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Sample records for isolated frog heart

  1. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  2. Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

    DEFF Research Database (Denmark)

    Ariel, Ellen; Subramaniam, Kuttichantran; Imnoi, Kamonchai

    2017-01-01

    Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus) during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad r...

  3. Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands.

    Science.gov (United States)

    Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal; Gröne, Andrea; Kik, Marja J L

    2017-08-31

    Frog virus 3 was isolated from a strawberry poison frog ( Oophaga pumilio ) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op /2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the reference Frog virus 3 isolate. Copyright © 2017 Saucedo et al.

  4. Complete Genome Sequence of Frog virus 3, Isolated from a Strawberry Poison Frog (Oophaga pumilio) Imported from Nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; van Beurden, Steven J; Suárez, Nicolás M; Haenen, Olga L M; Voorbergen-Laarman, Michal A; Gröne, Andrea; Kik, Marja J L

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  5. Complete genome sequence of frog virus 3, isolated from a strawberry poison frog (Oophaga pumilio) imported from nicaragua into the Netherlands

    NARCIS (Netherlands)

    Saucedo, Bernardo; Hughes, Joseph; Beurden, van Steven J.; Suárez, Nicolás M.; Haenen, Olga L.M.; Voorbergen-Laarman, Michal; Gröne, Andrea; Kika, Marja J.L.

    2017-01-01

    Frog virus 3 was isolated from a strawberry poison frog (Oophaga pumilio) imported from Nicaragua via Germany to the Netherlands, and its complete genome sequence was determined. Frog virus 3 isolate Op/2015/Netherlands/UU3150324001 is 107,183 bp long and has a nucleotide similarity of 98.26% to the

  6. Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

    Science.gov (United States)

    Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

    2017-05-01

    Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

  7. Characterizing potential heart agents with an isolated perfused heart system

    International Nuclear Information System (INIS)

    Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

    1984-01-01

    The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood

  8. A consistent nomenclature of antimicrobial peptides isolated from frogs of the subfamily Phyllomedusinae.

    Science.gov (United States)

    Amiche, Mohamed; Ladram, Ali; Nicolas, Pierre

    2008-11-01

    A growing number of cationic antimicrobial peptides have been isolated from the skin of hylid frogs belonging to the Phyllomedusinae subfamily. The amino acid sequences of these peptides are currently located in several databases under identifiers with no consistent system of nomenclature to describe them. In order to provide a workable terminology for antimicrobial peptides from Phyllomedusid frogs, we have made a systematic effort to collect, analyze, and classify all the Phyllomedusid peptide sequences available in databases. We propose that frogs belonging to the Phyllomedusinae subfamily should be described by the species names set out in Amphibian Species of the World: http://research.amnh.org/herpetology/amphibia/index.php, American Museum of Natural History, New York, USA. Multiple alignments analysis of at least 80 antimicrobial peptides isolated from 12 Phyllomedusinae species were distributed in seven distinct peptide families including dermaseptin, phylloseptin, plasticin, dermatoxin, phylloxin, hyposin and orphan peptides, and will be considered as the name of the headgroup of each family. The parent peptide's name should be followed by the first upper letter of the species for orthologous peptides and publication date determines priority. For example, the abbreviation B for bicolor and H for hypochondrialis. When two species begin with the same letter, two letters in upper case should be used (the first letter followed by the second or the third letter and so on). For example, the abbreviation DI for distincta, DU for duellmani, VA for vaillanti and VN for vanzolinii. Paralogous peptides should bear letter(s) in upper case followed by numbers.

  9. Protective effect of taurine on the light-induced disruption of isolated frog rod outer segments

    International Nuclear Information System (INIS)

    Pasantes-Morales, H.; Ademe, R.M.; Quesada, O.

    1981-01-01

    Isolated frog rod outer segments (ROS) incubated in a Krebs-bicarbonate medium, and illuminated for 2 h, show a profound alteration in their structure. This is characterized by distention of discs, vesiculation, and a marked swelling. The light-induced ROS disruption requires the presence of bicarbonate and sodium chloride. Replacement of bicarbonate by TRIS or HEPES protects ROS structure. Also, substitution of sodium chloride by sucrose or choline chloride maintains unaltered the ROS structure. Deletion of calcium, magnesium, or phosphate does not modify the effect produced by illumination. An increased accumulation of labeled bicarbonate and tritiated water is observed in illuminated ROS, as compared with controls in the dark. The presence of taurine, GABA, or glycine, at concentrations of 5-25 mM, effectively counteracts the light-induced ROS disruption. Taurine (25 mM) reduces labeled bicarbonate and tritiated water levels to those observed in the dark incubated ROS

  10. Total excitation of the isolated human heart

    NARCIS (Netherlands)

    Durrer, D.; Dam, R.Th. van; Freud, G.E.; Janse, M.J.; Meijler, F.L.; Arzbaecher, R.C.

    To obtain information conceming the time course and instantaneous distribution of the excitatory process of the normal human healt, studies were made on isolated human hearts from seven individuals who died from various cerebral conditions, but who had no history of cardiac disease. Measurements

  11. Two-photon excited autofluorescence imaging of freshly isolated frog retinas.

    Science.gov (United States)

    Lu, Rong-Wen; Li, Yi-Chao; Ye, Tong; Strang, Christianne; Keyser, Kent; Curcio, Christine A; Yao, Xin-Cheng

    2011-06-01

    The purpose of this study was to investigate cellular sources of autofluorescence signals in freshly isolated frog (Rana pipiens) retinas. Equipped with an ultrafast laser, a laser scanning two-photon excitation fluorescence microscope was employed for sub-cellular resolution examination of both sliced and flat-mounted retinas. Two-photon imaging of retinal slices revealed autofluorescence signals over multiple functional layers, including the photoreceptor layer (PRL), outer nuclear layer (ONL), outer plexiform layer (OPL), inner nuclear layer (INL), inner plexiform layer (IPL), and ganglion cell layer (GCL). Using flat-mounted retinas, depth-resolved imaging of individual retinal layers further confirmed multiple sources of autofluorescence signals. Cellular structures were clearly observed at the PRL, ONL, INL, and GCL. At the PRL, the autofluorescence was dominantly recorded from the intracellular compartment of the photoreceptors; while mixed intracellular and extracellular autofluorescence signals were observed at the ONL, INL, and GCL. High resolution autofluorescence imaging clearly revealed mosaic organization of rod and cone photoreceptors; and sub-cellular bright autofluorescence spots, which might relate to connecting cilium, was observed in the cone photoreceptors only. Moreover, single-cone and double-cone outer segments could be directly differentiated.

  12. A Brucella spp. Isolate from a Pac-Man Frog (Ceratophrys ornata) Reveals Characteristics Departing from Classical Brucellae.

    Science.gov (United States)

    Soler-Lloréns, Pedro F; Quance, Chris R; Lawhon, Sara D; Stuber, Tod P; Edwards, John F; Ficht, Thomas A; Robbe-Austerman, Suelee; O'Callaghan, David; Keriel, Anne

    2016-01-01

    Brucella are highly infectious bacterial pathogens responsible for brucellosis, a frequent worldwide zoonosis. The Brucella genus has recently expanded from 6 to 11 species, all of which were associated with mammals; The natural host range recently expanded to amphibians after some reports of atypical strains from frogs. Here we describe the first in depth phenotypic and genetic characterization of a Brucella strains isolated from a frog. Strain B13-0095 was isolated from a Pac-Man frog ( Ceratophyrus ornate ) at a veterinary hospital in Texas and was initially misidentified as Ochrobactrum anthropi . We found that B13-0095 belongs to a group of early-diverging brucellae that includes Brucella inopinata strain BO1 and the B. inopinata -like strain BO2, with traits that depart significantly from those of the "classical" Brucella spp. Analysis of B13-0095 genome sequence revealed several specific features that suggest that this isolate represents an intermediate between a soil associated ancestor and the host adapted "classical" species. Like strain BO2, B13-0095 does not possess the genes required to produce the perosamine based LPS found in classical Brucella , but has a set of genes that could encode a rhamnose based O-antigen. Despite this, B13-0095 has a very fast intracellular replication rate in both epithelial cells and macrophages. Finally, another major finding in this study is the bacterial motility observed for strains B13-0095, BO1, and BO2, which is remarkable for this bacterial genus. This study thus highlights several novel characteristics in strains belonging to an emerging group within the Brucella genus. Accurate identification tools for such atypical Brucella isolates and careful evaluation of their zoonotic potential, are urgently required.

  13. Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Summers, Kyle

    2014-01-01

    study the Peruvian poison frog Ranitomeya imitator, a species that has undergone a mimetic radiation into four distinct morphs. Using a combination of colour–pattern analysis, landscape genetics and mate-choice experiments, we show that a mimetic shift in R. imitator is associated with a narrow...

  14. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  15. Isolated heart models: cardiovascular system studies and technological advances.

    Science.gov (United States)

    Olejnickova, Veronika; Novakova, Marie; Provaznik, Ivo

    2015-07-01

    Isolated heart model is a relevant tool for cardiovascular system studies. It represents a highly reproducible model for studying broad spectrum of biochemical, physiological, morphological, and pharmaceutical parameters, including analysis of intrinsic heart mechanics, metabolism, and coronary vascular response. Results obtained in this model are under no influence of other organ systems, plasma concentration of hormones or ions and influence of autonomic nervous system. The review describes various isolated heart models, the modes of heart perfusion, and advantages and limitations of various experimental setups. It reports the improvements of perfusion setup according to Langendorff introduced by the authors.

  16. Communication: Effect of diperoxovandate on isolated rat heart ...

    African Journals Online (AJOL)

    Diperoxovanadate (DPV), a product of vanadate is gaining importance as a biologically active vanadium compound. The aim of the present study was to evaluate the chronotropic and inotropic activity of DPV using isolated rat heart and to determine the concentration at which it is toxic to the heart. The study was carried out ...

  17. Complete inhibition of creatine kinase in isolated perfused rat hearts

    International Nuclear Information System (INIS)

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. 31 P-NMR of the heart was carried out

  18. Isolation, structure, synthesis, and activity of a new member of the calcitonin gene-related peptide family from frog skin and molecular cloning of its precursor.

    Science.gov (United States)

    Seon, A A; Pierre, T N; Redeker, V; Lacombe, C; Delfour, A; Nicolas, P; Amiche, M

    2000-02-25

    Calcitonin gene-related peptide has been extracted from the skin exudate of a single living specimen of the frog Phyllomedusa bicolor and purified to homogeneity by a two-step protocol. A total volume of 250 microl of exudate yielded 380 microg of purified peptide. Mass spectrometric analysis and gas phase sequencing of the purified peptide as well as chemical synthesis and cDNA analysis were consistent with the structure SCDTSTCATQRLADFLSRSGGIGSPDFVPTDVSANSF amide and the presence of a disulfide bridge linking Cys(2) and Cys(7). The skin peptide, named skin calcitonin gene-related peptide, differs significantly from all other members of the calcitonin gene-related peptide family of peptides at nine positions but binds with high affinity to calcitonin gene-related peptide receptors in the rat brain and acts as an agonist in the rat vas deferens bioassay with potencies equal to those of human CGRP. Reverse transcriptase-polymerase chain reaction coupled with cDNA cloning and sequencing demonstrated that skin calcitonin gene-related peptide isolated in the skin is identical to that present in the frog's central and enteric nervous systems. These data, which indicate for the first time the existence of calcitonin gene-related peptide in the frog skin, add further support to the brain-skin-gut triangle hypothesis as a useful tool in the identification and/or isolation of mammalian peptides that are present in the brain and other tissues in only minute quantities.

  19. Frog Statistics

    Science.gov (United States)

    Whole Frog Project and Virtual Frog Dissection Statistics wwwstats output for January 1 through duplicate or extraneous accesses. For example, in these statistics, while a POST requesting an image is as well. Note that this under-represents the bytes requested. Starting date for following statistics

  20. Perceived Social Isolation and Outcomes in Patients With Heart Failure.

    Science.gov (United States)

    Manemann, Sheila M; Chamberlain, Alanna M; Roger, Véronique L; Griffin, Joan M; Boyd, Cynthia M; Cudjoe, Thomas K M; Jensen, Daniel; Weston, Susan A; Fabbri, Matteo; Jiang, Ruoxiang; Finney Rutten, Lila J

    2018-05-23

    Perceived social isolation has been shown to have a negative impact on health outcomes, particularly among older adults. However, these relationships have not been fully examined among patients with heart failure. Residents from 11 southeast Minnesota counties with a first-ever International Classification of Diseases, Ninth Revision ( ICD-9 ) code 428 for heart failure between January 1, 2013, and March 31, 2015 (N=3867), were prospectively surveyed to measure perceived social isolation. A total of 2003 patients returned the survey (response rate, 52%); 1681 patients completed all questions and were retained for analysis. Among these patients (53% men; mean age, 73 years), ≈19% (n=312) had moderate perceived social isolation and 6% (n=108) had high perceived social isolation. After adjustment, patients reporting moderate perceived social isolation did not have an increased risk of death, hospitalizations, or emergency department visits compared with patients reporting low perceived social isolation; however, patients reporting high perceived social isolation had >3.5 times increased risk of death (hazard ratio, 3.74; 95% confidence interval [CI], 1.82-7.70), 68% increased risk of hospitalization (hazard ratio, 1.68; 95% CI, 1.18-2.39), and 57% increased risk of emergency department visits (hazard ratio, 1.57; 95% CI, 1.09-2.27). Compared with patients who self-reported low perceived social isolation, patients reporting moderate perceived social isolation had a 16% increased risk of outpatient visits (rate ratio, 1.16; 95% CI, 1.03-1.31), whereas those reporting high perceived social isolation had a 26% increased risk (rate ratio, 1.26; 95% CI, 1.04-1.53). In patients with heart failure, greater perceived social isolation is associated with an increased risk of death and healthcare use. Assessing perceived social isolation during the clinical encounter with a brief screening tool may help identify patients with heart failure at greater risk of poor outcomes.

  1. Polarographic measurement of ascorbate washout in isolated perfused rabbit hearts

    International Nuclear Information System (INIS)

    Arts, T.; Kuikka, J.T.; Reneman, R.S.; Bassingthwaighte, J.B.

    1985-01-01

    To study the myocardial washout of ascorbate, the applicability of polarographic detection of ascorbate ions by a platinum electrode (sensitive area 0.03 mm2) was investigated, in both a calibration setup (sampling flow along the electrode: 100 microliter X s-1) and isolated, retrogradely perfused rabbit hearts. In the calibration setup at pH 7.4, the sensitivity of the electrode was 70 microA/mol. This sensitivity increased moderately with increasing pH (13%/unit pH) and increasing sampling flow rate (14% at an increase from 100 to 150 microliter X s-1). In the isolated hearts, ascorbate infused into the aorta was detected in a right ventricular drain by the electrode as well as by the use of 14 C-labeled ascorbate. Both recorded time courses were similar except for a scaling factor dependent on flow velocity. During continuous infusion the arteriovenous difference of ascorbate was 2 +/- 2% (SD), indicating a relatively low consumption of ascorbate by the isolated heart. The authors conclude that polarographic measurement of ascorbate in the coronary effluent of an isolated rabbit heart can be performed on-line and relatively easily

  2. Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

    Science.gov (United States)

    Pfeiler, E; Markow, T A

    2008-10-01

    Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives.

  3. Frog eat frog: exploring variables influencing anurophagy

    OpenAIRE

    Measey, G. John; Vimercati, Giovanni; de Villiers, F. Andr?; Mokhatla, Mohlamatsane M.; Davies, Sarah J.; Edwards, Shelley; Altwegg, Res

    2015-01-01

    Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet ...

  4. Hyperthyroidism presenting as isolated tricuspid regurgitation and right heart failure.

    Science.gov (United States)

    Whitner, Tanya E; Hudson, Christopher J; Smith, Timothy D; Littmann, Laszlo

    2005-01-01

    Although hyperthyroidism has many signs and symptoms, right heart failure can occasionally be the main presenting symptom. We describe the case of a previously healthy 42-year-old woman whose chief complaint was progressive bilateral lower extremity edema. The echocardiogram revealed right atrial dilatation and moderate-to-severe tricuspid regurgitation. Results of laboratory studies were consistent with hyperthyroidism. Thyroid ablation resulted in permanent resolution of symptoms and resolution of tricuspid incompetence on echocardiography. In a case of isolated, unexplained tricuspid regurgitation, it is important to consider indolent hyperthyroidism in the differential diagnosis.

  5. Ciprofloxacin, an antibiotic with cardiac actions on isolated rat hearts

    Directory of Open Access Journals (Sweden)

    Loipa Galán-Martínez

    2018-04-01

    Full Text Available Context: Ciprofloxacin is the most commonly used fluoroquinolone and is prescribed as the antibiotic of choice in the treatment of several microbial infections. Some clinical reports have suggested that ciprofloxacin may induce QT-interval prolongation and Torsades de Pointes arrhythmias. This drug is a weak inhibitor of a rapid component of the cardiac delayed rectifier potassium current IKr, but there are few electrophysiological data available to assess whether ciprofloxacin has the potency to provoke QT prolongation and subsequent Torsades de Pointes arrhythmias. Aims: To evaluate the effect of ciprofloxacin on the contractile and electrical activity of isolated rat hearts. Methods: The Langendorff technique was performed in rat hearts, and the effects of ciprofloxacin (0.001 – 100 μM were measured on the cardiac force of contraction and on the RR, QRS and QTc intervals. The arrhythmogenic potential and the ventricular fibrillation threshold were evaluated with ciprofloxacin. Results: Ciprofloxacin decreased the force of contraction of all hearts studied, in a concentration-dependent manner. The estimated IC50 for the inotropic negative effect was 0.15 ± 0.04 μM. Ciprofloxacin significantly prolonged the QRS complex, QTc and RR interval. Significant arrhythmic effects with ciprofloxacin were shown and the ventricular fibrillation threshold was decreased. Conclusions: These results suggest that ciprofloxacin exerted effects on cardiac Na+, K+ and Ca2+ channels. The actions of ciprofloxacin require further studies at the cellular level. These conclusions may account for clinical data that have been reported previously.

  6. Metabolic variations of fatty acid in isolated rat heart reperfused after a transient global ischemia

    International Nuclear Information System (INIS)

    Huang Gang; Michel Comet; Zhao Huiyang; Zhu Cuiying; Yuan Jimin

    1998-01-01

    Purpose: The fatty acid metabolism and the effect of glucose on it were studied in isolated and reperfused rat heat. Methods: 32 isolated working rat hearts were perfused in Langengdorff device with modified Krebs and were divided into normal and ischemia-reperfused group. Each group was also classified into two subgroups, modified krebs with or without glucose subgroup. 131 I-HA was injected into aorta of isolated working rat heart and then the radio-residue curves were acquired. Results: When the isolated rat hearts were perfused with krebs plus glucose, the catabolism of fatty acid was significantly decreased in normal group, but a remarkable increase of fatty acid catabolism was found in ischemia-reperfused group. While the isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat hearts were perfused with krebs without glucose, the catabolism of fatty acid in ischemia-reperfused isolated rat heart was less than that in normal group. Conclusions: Transient ischemia damages the catabolism of myocardial fatty acid in mitochondria in some degree. In normal isolated working rat heart, the principal energy source is glucose. However, the major energy source is switched to catabolism of fatty acid in ischemia-reperfused isolated rat heart. This phenomenon may be related to compensative increase of fatty acid catabolism for replenishing the loss of energy during ischemia

  7. Stimulation of Na+-alanine cotransport activates a voltage-dependent conductance in single proximal tubule cells isolated from frog kidney

    Science.gov (United States)

    Robson, L; Hunter, M

    1999-01-01

    The swelling induced by Na+-alanine cotransport in proximal tubule cells of the frog kidney is followed by regulatory volume decrease (RVD). This RVD is inhibited by gadolinium (Gd3+), an inhibitor of stretch-activated channels, but is independent of extracellular Ca2+. In this study, the whole cell patch clamp technique was utilized to examine the effect of Na+-alanine cotransport on two previously identified volume- and Gd3+-sensitive conductances. One conductance is voltage dependent and anion selective (GVD) whilst the other is voltage independent and cation selective (GVI). Addition of 5 mM L-alanine to the bathing solution increased the whole cell conductance and gave a positive (depolarizing) shift in the reversal potential (Vrev, equivalent to the membrane potential in current-clamped cells) consistent with activation of Na+-alanine cotransport. Vrev shifted from -36 ± 4·9 to +12·9 ± 4·2 mV (n= 15). In the presence of alanine, the total whole cell conductance had several components including the cotransporter conductance and GVD and GVI. These conductances were separated using Gd3+, which inhibits both GVD and GVI, and the time dependency of GVD. Of these two volume-sensitive conductances, L-alanine elicited a specific increase in GVD, whereas GVI was unaffected. The L-alanine-induced activation of GVD was significantly reduced when cells were incubated in a hypertonic bathing solution. In summary, in single proximal tubule cells isolated from frog kidney, on stimulation of Na+-alanine cotransport GVD is activated, while GVI is unaffected. Taken with other evidence, this suggests that GVD is activated by cell swelling, consequent upon alanine entry, and may play a role as an anion efflux pathway during alanine-induced volume regulation. PMID:10226159

  8. In vitro assessment of cardiac performance after irradiation using an isolated working rat heart preparation

    International Nuclear Information System (INIS)

    Wondergem, J.; Laarse, A. van der; Ravels, F.J.M. van; Wermeskerken, A.-M. van; Verhoeve, H.R.; Graaf, B.W. de; Leer, J.W.H.

    1991-01-01

    The effect of irradiation on cardiac function was assessed using an isolated working rat heart preparation. The animals were given single doses of X-rays in the range 15-30 Gy to their hearts. Cardiac output (CO = aortic flow + coronary flow), heart weight and body weight were followed for a period of 10 months after treatment. Irradiation led to a decrease in cardiac function. This reduction was dose-dependent and progressive with time after treatment. The shape of the Frank-Starling curves constructed for irradiated hearts suggests a loss of contractile function of the myocardium. Coronary flow rates measured in 'working' hearts and in 'Langendorff' hearts were not significantly changed by the irradiation treatment. The isolated working rat heart preparation proved to be a simple and suitable animal model for the investigation of irradiation-induced cardiotoxicity. (author)

  9. Expression of cardiac neural crest and heart genes isolated by modified differential display.

    Science.gov (United States)

    Martinsen, Brad J; Groebner, Nathan J; Frasier, Allison J; Lohr, Jamie L

    2003-08-01

    The invasion of the cardiac neural crest (CNC) into the outflow tract (OFT) and subsequent outflow tract septation are critical events during vertebrate heart development. We have performed four modified differential display screens in the chick embryo to identify genes that may be involved in CNC, OFT, secondary heart field, and heart development. The screens included differential display of RNA isolated from three different axial segments containing premigratory cranial neural crest cells; of RNA from distal outflow tract, proximal outflow tract, and atrioventricular tissue of embryonic chick hearts; and of RNA isolated from left and right cranial tissues, including the early heart fields. These screens have resulted in the identification of the five cDNA clones presented here, which are expressed in the cardiac neural crest, outflow tract and developing heart in patterns that are unique in heart development.

  10. Seasonal variations of cellular stress response in the heart and gastrocnemius muscle of the water frog (Pelophylax ridibundus).

    Science.gov (United States)

    Feidantsis, Konstantinos; Anestis, Andreas; Vasara, Eleni; Kyriakopoulou-Sklavounou, Pasqualina; Michaelidis, Basile

    2012-08-01

    The present study aimed to investigate the seasonal cellular stress response in the heart and the gastrocnemius muscle of the amphibian Pelophylax ridibundus (former name Rana ridibunda) during an 8 month acclimatization period in the field. Processes studied included heat shock protein expression and protein kinase activation. The cellular stress response was addressed through the expression of Hsp70 and Hsp90 and the phosphorylation of stress-activated protein kinases and particularly p38 mitogen-activated protein kinase (p38 MAPK), the extracellular signal-regulated kinases (ERK-1/2) and c-Jun N-terminal kinases (JNK1/2/3). Due to a general metabolic depression during winter hibernation, the induction of Hsp70 and Hsp90 and the phosphorylation of p38 MAPK, JNKs and ERKs are retained at low levels of expression in the examined tissues of P. ridibundus. Recovery from hibernation induces increased levels of the specific proteins, probably providing stamina to the animals during their arousal. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Primary afferent depolarization and changes in extracellular potassium concentration induced by L-glutamate and L-proline in the isolated spinal cord of the frog.

    Science.gov (United States)

    Vyklický, L; Vyskocil, F; Kolaj, M; Jastreboff, P

    1982-10-08

    To test the hypothesis that L-proline acts as an antagonist on glutamate receptors [17, 18], the interaction between L-glutamate and L-proline was studied in the isolated spinal cord of the frog. Glutamate at concentrations of 10(-6) -5 x 10(-3) mol/l depolarized the primary afferent fibres and increased extracellular potassium concentration, [K+]e, by 0.3-4 mmol/l. Repeated applications lead to inactivation of the response. L-Proline at 5 x 10(-3) -10(-2) mol/l, also depolarized the primary afferents and increased [K+]e by 0.5-2 mmol/l, but there was only a slight decrease of the effects after repeated application. The effects were additive when the amino acids were applied simultaneously. The effect of L-proline was still present when it was applied during inactivation of the glutamate receptors. This suggests that L-glutamate and L-proline act on different receptors.

  12. Frog eat frog: exploring variables influencing anurophagy.

    Science.gov (United States)

    Measey, G John; Vimercati, Giovanni; de Villiers, F André; Mokhatla, Mohlamatsane M; Davies, Sarah J; Edwards, Shelley; Altwegg, Res

    2015-01-01

    Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested. Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis. Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet. Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

  13. Frog eat frog: exploring variables influencing anurophagy

    Directory of Open Access Journals (Sweden)

    G. John Measey

    2015-08-01

    Full Text Available Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis.Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

  14. Isolation of dermatoxin from frog skin, an antibacterial peptide encoded by a novel member of the dermaseptin genes family.

    Science.gov (United States)

    Amiche, M; Seon, A A; Wroblewski, H; Nicolas, P

    2000-07-01

    A 32-residue peptide, named dermatoxin, has been extracted from the skin of a single specimen of the tree frog Phyllomedusa bicolor, and purified to homogeneity using a four-step protocol. Mass spectral analysis and sequencing of the purified peptide, as well as chemical synthesis and cDNA analysis were consistent with the structure: SLGSFLKGVGTTLASVGKVVSDQF GKLLQAGQ. This peptide proved to be bactericidal towards mollicutes (wall-less eubacteria) and Gram-positive eubacteria, and also, though to a lesser extent, towards Gram-negative eubacteria. Measurement of the bacterial membrane potential revealed that the plasma membrane is the primary target of dermatoxin. Observation of bacterial cells using reflected light fluorescence microscopy after DNA-staining was consistent with a mechanism of cell killing based upon the alteration of membrane permeability rather than membrane solubilization, very likely by forming ion-conducting channels through the plasma membrane. CD spectroscopy and secondary structure predictions indicated that dermatoxin assumes an amphipathic alpha-helical conformation in low polarity media which mimic the lipophilicity of the membrane of target microorganisms. PCR analysis coupled with cDNA cloning and sequencing revealed that dermatoxin is expressed in the skin, the intestine and the brain. Preprodermatoxin from the brain and the intestine have the same sequence as the skin preproform except for two amino-acid substitutions in the preproregion of the brain precursor. The dermatoxin precursor displayed the characteristic features of preprodermaseptins, a family of peptide precursors found in the skin of Phyllomedusa ssp. Precursors of this family have a common N-terminal preproregion followed by markedly different C-terminal domains that give rise to 19-34-residue peptide antibiotics named dermaseptins B and phylloxin, and to the D-amino-acid-containing opioid heptapeptides dermorphins and deltorphins. Because the structures and cidal

  15. Isolated working heart: description of models relevant to radioisotopic and pharmacological assessments

    International Nuclear Information System (INIS)

    Depre, Christophe

    1998-01-01

    Isolated heart preparations are used to study physiological and metabolic parameters of the heart independently of its environment. Several preparations of isolated perfused heart are currently used, mainly the retrograde perfusion system and the working heart model. Both models allow investigations of the metabolic regulation of the heart in various physiological conditions (changes in workload, hormonal influences, substrate competition). These systems may also reproduce different pathological conditions, such as ischemia, reperfusion and hypoxia. Quantitation of metabolic activity can be performed with specific radioactive tracers. Finally, the effects of various drugs on cardiac performance and resistance to ischemia can be studied as well. Heart perfusion also revealed efficient methods to determine the tracer/tracee relation for radioisotopic analogues used with Positron Emission Tomography

  16. Effects of ketamine and its isomers on ischemic preconditioning in the isolated rat heart

    NARCIS (Netherlands)

    Molojavyi, A.; Preckel, B.; Comfère, T.; Müllenheim, J.; Thämer, V.; Schlack, W.

    2001-01-01

    BACKGROUND: Ischemic preconditioning protects the heart against subsequent ischemia. Opening of the adenosine triphosphate-sensitive potassium (KATP) channel is a key mechanism of preconditioning. Ketamine blocks KATP channels of isolated cardiomyocytes. The authors investigated the effects of

  17. Reversible Pulmonary Hypertension and Isolated Right-sided Heart Failure Associated with Hyperthyroidism

    OpenAIRE

    Ismail, Hassan M.

    2007-01-01

    Hyperthyroidism may present with signs and symptoms related to dysfunction of a variety of organs. Cardiovascular pathology in hyperthyroidism is common. A few case reports describe isolated right heart failure, tricuspid regurgitation, and pulmonary hypertension as the prominent cardiovascular manifestations of hyperthyroidism. Although most textbooks do not mention hyperthyroidism as a cause of pulmonary hypertension and isolated right heart failure, the literature suggests that some hypert...

  18. Fetal and neonatal mortality in patients with isolated congenital heart diseases and heart conditions associated with extracardiac abnormalities.

    Science.gov (United States)

    Marantz, Pablo; Sáenz Tejeira, M Mercedes; Peña, Gabriela; Segovia, Alejandra; Fustiñana, Carlos

    2013-10-01

    Congenital malformations are a known cause of intrauterine death; of them, congenital heart diseases (CHDs) are accountable for the highest fetal and neonatal mortality rates. They are strongly associated with other extracardiac malformations and an early fetal mortality. Two hundred and twenty fves cases of CHDs are presented. Of them, 155 were isolated CHDs (group A) and 70 were associated with extracardiac malformations, chromosomal disorders, or genetic syndromes (group B). The overall mortality in group B was higher than that observed in group A (p Heart diseases associated with extracardiac abnormalities had a higher mortality rate than isolated congenital heart diseases in the period up to 60 weeks of postmenstrual age (140 days post-term). No differences were observed between both groups of patients in terms of prenatal mortality.

  19. Transcapillary transport of metaiodobenzylguanidine (MIBG) in isolated rat heart

    International Nuclear Information System (INIS)

    DeGrado, Timothy R.; Wang Shuyan

    1998-01-01

    A better understanding of transcapillary transport for tracer metaiodobenzylguanidine (MIBG) is desirable for development of tracer kinetic models that yield meaningful estimates of neuronal uptake function from tissue radioactivity time courses. This study utilized a multiple-indicator approach in Langendorff-perfused rat hearts to define transport mechanisms and determine the capillary permeability-surface area (PSc) over a broad range of flow (F). Multiple injections within the same heart at different flows allowed characterization of the PSc/F relationship within the same heart. The coefficient of variation of E for multiple injections within the same hearts at constant flow was 6±2% (3 to 6 injections in 9 hearts). In 10 hearts (4 to 6 injections per heart), flow was varied between 2.0-16.5 mL/min. PSc was found to be nearly proportional to flow in each heart (r=0.88±0.14; slope = 0.23±0.10; intercept = 11±7 mL/min/g dry). Tissue hypoxia at low flows, as evidenced by enhanced lactate production, did not appear to influence the PSc/F relationship. Pharmacologic blockade of uptake-1 and uptake-2 had negligible affect on E or PSc as compared with flow-matched controls, although tissue retention was markedly reduced. The results show PSc of MIBG to be nearly proportional to flow but independent of specific neuronal and extraneuronal transport mechanisms and tissue hypoxia. The results are consistent with a passive diffusion process across the capillary endothelial barrier. The increase in PSc with increasing flow could reflect capillary recruitment and/or enhanced capillary permeability

  20. Electromechanical effects of bepridil on rabbit isolated hearts.

    OpenAIRE

    Anno, T.; Furuta, T.; Itoh, M.; Kodama, I.; Toyama, J.; Yamada, K.

    1984-01-01

    Electromechanical effects of a new antianginal agent, bepridil, on Langendorff-perfused rabbit hearts were compared with those of verapamil and lidocaine. Bepridil at concentrations above 2 X 10(-7)M caused a dose-related decrease in heart rate (HR), a prolongation of the atrio-His bundle conduction time (A-H interval) and a prolongation of the functional refractory period (FRP) of the atrioventricular (A-V) node. Similar changes in HR, A-H interval and the FRP of the A-V node were observed w...

  1. Stabilization of mitochondrial membrane potential prevents doxorubicin-induced cardiotoxicity in isolated rat heart

    International Nuclear Information System (INIS)

    Montaigne, David; Marechal, Xavier; Baccouch, Riadh; Modine, Thomas; Preau, Sebastien; Zannis, Konstantinos; Marchetti, Philippe; Lancel, Steve; Neviere, Remi

    2010-01-01

    The present study was undertaken to examine the effects of doxorubicin on left ventricular function and cellular energy state in intact isolated hearts, and, to test whether inhibition of mitochondrial membrane potential dissipation would prevent doxorubicin-induced mitochondrial and myocardial dysfunction. Myocardial contractile performance and mitochondrial respiration were evaluated by left ventricular tension and its first derivatives and cardiac fiber respirometry, respectively. NADH levels, mitochondrial membrane potential and glucose uptake were monitored non-invasively via epicardial imaging of the left ventricular wall of Langendorff-perfused rat hearts. Heart performance was reduced in a time-dependent manner in isolated rat hearts perfused with Krebs-Henseleit solution containing 1 μM doxorubicin. Compared with controls, doxorubicin induced acute myocardial dysfunction (dF/dt max of 105 ± 8 mN/s in control hearts vs. 49 ± 7 mN/s in doxorubicin-treated hearts; *p < 0.05). In cardiac fibers prepared from perfused hearts, doxorubicin induced depression of mitochondrial respiration (respiratory control ratio of 4.0 ± 0.2 in control hearts vs. 2.2 ± 0.2 in doxorubicin-treated hearts; *p < 0.05) and cytochrome c oxidase kinetic activity (24 ± 1 μM cytochrome c/min/mg in control hearts vs. 14 ± 3 μM cytochrome c/min/mg in doxorubicin-treated hearts; *p < 0.05). Acute cardiotoxicity induced by doxorubicin was accompanied by NADH redox state, mitochondrial membrane potential, and glucose uptake reduction. Inhibition of mitochondrial permeability transition pore opening by cyclosporine A largely prevented mitochondrial membrane potential dissipation, cardiac energy state and dysfunction. These results suggest that in intact hearts an impairment of mitochondrial metabolism is involved in the development of doxorubicin cardiotoxicity.

  2. Hyperthyroidism: Presenting as Isolated Tricuspid Regurgitation and Right Heart Failure

    OpenAIRE

    Whitner, Tanya E.; Hudson, Christopher J.; Smith, Timothy D.; Littmann, Laszlo

    2005-01-01

    Although hyperthyroidism has many signs and symptoms, right heart failure can occasionally be the main presenting symptom. We describe the case of a previously healthy 42-year-old woman whose chief complaint was progressive bilateral lower extremity edema. The echocardiogram revealed right atrial dilatation and moderate-to-severe tricuspid regurgitation. Results of laboratory studies were consistent with hyperthyroidism. Thyroid ablation resulted in permanent resolution of symptoms and resolu...

  3. Chamber-specific effects of hypokalaemia on ventricular arrhythmogenicity in isolated, perfused guinea-pig heart

    DEFF Research Database (Denmark)

    Osadchii, Oleg E; Bentzen, Bo Hjorth; Olesen, Søren-Peter

    2009-01-01

    of hypokalaemic perfusion (2.5 mm K(+) for 30 min) were assessed in isolated guinea-pig heart preparations using simultaneous recordings of volume-conducted electrocardiogram and monophasic action potentials from six ventricular epicardial sites. Effective refractory periods, ventricular fibrillation thresholds...... for re-entrant tachyarrhythmias. Taken together, these findings suggest that proarrhythmic effects of hypokalaemia are mostly attributed to increased LV arrhythmogenicity in the guinea-pig heart....

  4. Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations

    Directory of Open Access Journals (Sweden)

    Petrucci Júnior O.

    2003-01-01

    Full Text Available In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max, first derivative of minimum pressure (dP/dt min, systolic stress of the left ventricle (sigmas, and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.

  5. Uptake, incorporation and metabolism of (3H)triolein in the isolated perfused rabbit heart

    International Nuclear Information System (INIS)

    Weis, M.T.; Palazzo, A.J.; Williams, J.L. Jr.; Malik, K.U.

    1990-01-01

    The purpose of these experiments was to study the uptake and metabolism of exogenous triglyceride in the isolated perfused rabbit heart. When infused into the rabbit heart, [9,10-3H(N)]triolein was retained and incorporated into a lipid fraction that had the chromatographic mobility of authentic triolein. Incorporation of labeled triolein was not likely to be the result of a lipoprotein lipase-mediated lipolysis/resynthesis cycle, since: (i) The distribution of radioactivity following administration of [3H]oleic acid was markedly different from the distribution of radioactivity following the administration of [3H]triolein; (ii) heparin was administered to the rabbits at the time of sacrifice; and (iii) the hearts were perfused with a protein-free buffer for 20 min prior to the labelling period. When isoproterenol was administered to hearts labelled with [3H]triolein, there was an increased output of total radioactivity, composed of labelled free fatty acids, diacylglycerol and monoacylglycerol. In these same hearts, there was an increased output of glycerol in response to isoproterenol. However, following the administration of bradykinin or angiotensin II, neither the radioactivity nor the glycerol content of the perfusate was changed. These data suggest that [3H]triolein is selectively incorporated into the triglyceride pool of the isolated perfused rabbit heart. Furthermore, this [3H]triolein is available to hormonally-activated lipolytic enzymes

  6. Plasma protein concentration and control of coronary vascular resistance in isolated rat heart

    NARCIS (Netherlands)

    Avolio, A. P.; Spaan, J. A.; Laird, J. D.

    1980-01-01

    Isolated externally paced (300 beats/min) rat hearts were perfused at constant pressure (70 mmHg) using a modified Krebs-Henseleit solution with (n = 52) and without (n = 15) washed bovine red cells. Albumin concentration varied from 1 to 10 g/dl. With increasing albumin concentration in

  7. Effect of increased left ventricle mass on ischemia assessment in electrocardiographic signals: rabbit isolated heart study

    Czech Academy of Sciences Publication Activity Database

    Ronzhina, M.; Olejníčková, Veronika; Stračina, T.; Nováková, M.; Janoušek, O.; Hejč, J.; Kolářová, J.; Hlaváčová, M.; Paulová, H.

    2017-01-01

    Roč. 17, Aug 4 (2017), č. článku 216. ISSN 1471-2261 Institutional support: RVO:67985823 Keywords : myocardial ischemia detection * increased left ventricular mass * electrogram * ROC analysis * isolated heart * rabbit Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery OBOR OECD: Physiology (including cytology) Impact factor: 1.832, year: 2016

  8. Heterogeneous response of isolated adult rat heart cells to insulin

    International Nuclear Information System (INIS)

    Haworth, R.A.; Hunter, D.R.; Berkoff, H.A.

    1984-01-01

    3-O-Methylglucose uptake by Ca2+-resistant adult rat heart cells in suspension was measured, free of artifactual inhibitor-insensitive uptake, and with an accuracy of +/- 1.9% pellet water. (Ca2+-resistant cells are cells which retain their original rod-shaped morphology in the presence of physiological levels of Ca2+.) High levels of insulin (10(-6) M) stimulated the rate of 3-O-methylglucose uptake approximately 10-fold. In the presence of low levels of insulin (3 X 10(-11) M, 10(-10) M) uptake was biphasic; it could not be described by a single exponential function within experimental error, but required the sum of two exponentials. Deviation from a single exponential function was not so great with high levels of insulin (10(-6) M) or no insulin. Cell sugar uptake was also investigated using autoradiography of cells which had accumulated [2-14C]deoxyglucose under similar conditions. This showed considerable heterogeneity of 2-deoxyglucose uptake by cells treated with low levels of insulin, but significantly less heterogeneity of 2-deoxyglucose uptake by cells treated with high levels of insulin. It is concluded that the deviation of 3-O-methylglucose uptake from a single exponential observed at low insulin levels can be accounted for in terms of a heterogeneous response of cells to insulin

  9. Ex vivo stretch reveals altered mechanical properties of isolated dystrophin-deficient hearts.

    Directory of Open Access Journals (Sweden)

    Matthew S Barnabei

    Full Text Available Duchenne muscular dystrophy (DMD is a progressive and fatal disease of muscle wasting caused by loss of the cytoskeletal protein dystrophin. In the heart, DMD results in progressive cardiomyopathy and dilation of the left ventricle through mechanisms that are not fully understood. Previous reports have shown that loss of dystrophin causes sarcolemmal instability and reduced mechanical compliance of isolated cardiac myocytes. To expand upon these findings, here we have subjected the left ventricles of dystrophin-deficient mdx hearts to mechanical stretch. Unexpectedly, isolated mdx hearts showed increased left ventricular (LV compliance compared to controls during stretch as LV volume was increased above normal end diastolic volume. During LV chamber distention, sarcomere lengths increased similarly in mdx and WT hearts despite greater excursions in volume of mdx hearts. This suggests that the mechanical properties of the intact heart cannot be modeled as a simple extrapolation of findings in single cardiac myocytes. To explain these findings, a model is proposed in which disruption of the dystrophin-glycoprotein complex perturbs cell-extracellular matrix contacts and promotes the apparent slippage of myocytes past each other during LV distension. In comparison, similar increases in LV compliance were obtained in isolated hearts from β-sarcoglycan-null and laminin-α(2 mutant mice, but not in dysferlin-null mice, suggesting that increased whole-organ compliance in mdx mice is a specific effect of disrupted cell-extracellular matrix contacts and not a general consequence of cardiomyopathy via membrane defect processes. Collectively, these findings suggest a novel and cell-death independent mechanism for the progressive pathological LV dilation that occurs in DMD.

  10. Kinetics of the norepinephrine analog [76Br]-meta-bromobenzylguanidine in isolated working rat heart

    International Nuclear Information System (INIS)

    Raffel, David; Loc'h, Christian; Mardon, Karine; Maziere, Bernard; Syrota, Andre

    1998-01-01

    A related set of kinetic studies of the norepinephrine analog [ 76 Br]-meta-bromobenzylguanidine (MBBG) were performed with an isolated working rat heart preparation. A series of constant infusion studies over a wide range of MBBG concentrations allowed estimation of the Michaelis-Menten constants for transport by the neuronal norepinephrine transporter (uptake 1 ) and the extraneuronal uptake system (uptake 2 ). Pharmacological blocking studies with inhibitors of uptake 1 , uptake 2 and vesicular uptake were performed to delineate the relative importance of these norepinephrine handling mechanisms on the kinetics of MBBG in the rat heart. Bolus injection studies were done to assess the ability of compartmental modeling techniques to characterize the kinetics of MBBG. These studies demonstrate that MBBG shares many of the same uptake mechanisms as norepinephrine in the rat heart. PET imaging studies with MBBG would be useful for assessing sympathetic nerve status in the living human heart

  11. Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

    Science.gov (United States)

    McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

    2016-06-01

    Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

  12. Myocardial 99mTc-sestamibi extraction and washout in hypertensive heart failure using an isolated rat heart

    International Nuclear Information System (INIS)

    Fukushima, Kenji; Momose, Mitsuru; Kondo, Chisato; Higuchi, Takahiro; Kusakabe, Kiyoko; Hagiwara, Nobuhisa

    2010-01-01

    Purpose: Myocardial mitochondria are the primary part of energy production for healthy cardiac contraction. And mitochondrial dysfunction would play an important role in progressive heart failure. In the recent years, myocardial washout of 99m Tc-sestamibi [( 99m Tc-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI)] has been introduced to be a potential marker in patients with heart failure. The objective of this study was to clarify MIBI extraction and washout kinetics using isolated perfusion system in hypertension induced model of myocardial dysfunction. Methods: Six-week-old Dahl-salt sensitive rats, allotted to 4 groups; a 5-week high-salt group (5wk-HS), 12-week high-salt group (12wk-HS) and two age-matched, low-salt diet control groups (5wk-LS and 12wk-LS). The rats in 5wk-HS and 12wk-HS groups were fed a high-salt diet (containing 8% NaCl). Cardiac function was examined by echocardiography before removing heart. Hearts were perfused according to the Langendorff method at a constant flow rate, in which 20-min MIBI washin was conducted followed by 25-min MIBI washout. Whole heart radioactivity was collected every sec by an external gamma detector. The myocardial extraction, K 1 (ml/min) and washout rate, k 2 (min -1 ) were generated. Results: High-salt diet groups showed significant high-blood pressure. Echocardiography revealed thickened LV walls in 5wk-HS, and reduced cardiac function in 12wk-HS, compared to each age-matched control group. K 1 showed no significant difference among all groups (5wk-HS: 2.36±1.07, 5wk-control: 2.59±0.28, 12wk-HS: 1.91±0.90, and 12wk-control: 2.84±0.57). k 2 in 5wk-HS was comparable to that in the age matched control group (0.00030±0.00039 vs -0.000010±0.00044), but it was increased remarkably in 18wk-HS compared to the age matched control group (0.0025±0.0011 vs 0.000025±0.000041, P<.01), and 5wk-HS (P<.01). Conclusion: In the course of hypertensive heart disease, MIBI washout was increased in the transitional state

  13. Myocardial {sup 99m}Tc-sestamibi extraction and washout in hypertensive heart failure using an isolated rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kenji [Department of Cardiology, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Department of Radiology, Johns Hopkins University, Baltimore, MD (United States); Momose, Mitsuru, E-mail: mmomose@rad.twmu.ac.j [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Kondo, Chisato [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Higuchi, Takahiro [Department of Radiology, Johns Hopkins University, Baltimore, MD (United States); Kusakabe, Kiyoko [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan); Hagiwara, Nobuhisa [Department of Cardiology, Tokyo Women' s Medical University, Tokyo 162-8666 (Japan)

    2010-11-15

    Purpose: Myocardial mitochondria are the primary part of energy production for healthy cardiac contraction. And mitochondrial dysfunction would play an important role in progressive heart failure. In the recent years, myocardial washout of {sup 99m}Tc-sestamibi [({sup 99m}Tc-hexakis-2-methoxy-2-methylpropyl isonitrile (MIBI)] has been introduced to be a potential marker in patients with heart failure. The objective of this study was to clarify MIBI extraction and washout kinetics using isolated perfusion system in hypertension induced model of myocardial dysfunction. Methods: Six-week-old Dahl-salt sensitive rats, allotted to 4 groups; a 5-week high-salt group (5wk-HS), 12-week high-salt group (12wk-HS) and two age-matched, low-salt diet control groups (5wk-LS and 12wk-LS). The rats in 5wk-HS and 12wk-HS groups were fed a high-salt diet (containing 8% NaCl). Cardiac function was examined by echocardiography before removing heart. Hearts were perfused according to the Langendorff method at a constant flow rate, in which 20-min MIBI washin was conducted followed by 25-min MIBI washout. Whole heart radioactivity was collected every sec by an external gamma detector. The myocardial extraction, K{sub 1} (ml/min) and washout rate, k{sub 2} (min{sup -1}) were generated. Results: High-salt diet groups showed significant high-blood pressure. Echocardiography revealed thickened LV walls in 5wk-HS, and reduced cardiac function in 12wk-HS, compared to each age-matched control group. K{sub 1} showed no significant difference among all groups (5wk-HS: 2.36{+-}1.07, 5wk-control: 2.59{+-}0.28, 12wk-HS: 1.91{+-}0.90, and 12wk-control: 2.84{+-}0.57). k{sub 2} in 5wk-HS was comparable to that in the age matched control group (0.00030{+-}0.00039 vs -0.000010{+-}0.00044), but it was increased remarkably in 18wk-HS compared to the age matched control group (0.0025{+-}0.0011 vs 0.000025{+-}0.000041, P<.01), and 5wk-HS (P<.01). Conclusion: In the course of hypertensive heart disease, MIBI

  14. Characterizing Spatial Dynamics of Bifurcation to Alternans in Isolated Whole Rabbit Hearts Based on Alternate Pacing

    Directory of Open Access Journals (Sweden)

    Kanchan Kulkarni

    2015-01-01

    Full Text Available Sudden cardiac death instigated by ventricular fibrillation (VF is the largest cause of natural death in the USA. Alternans, a beat-to-beat alternation in the action potential duration, has been implicated as being proarrhythmic. The onset of alternans is mediated via a bifurcation, which may occur through either a smooth or a border-collision mechanism. The objective of this study was to characterize the mechanism of bifurcation to alternans based on experiments in isolated whole rabbit hearts. High resolution optical mapping was performed and the electrical activity was recorded from the left ventricle (LV epicardial surface of the heart. Each heart was paced using an “alternate pacing protocol,” where the basic cycle length (BCL was alternatively perturbed by ±δ. Local onset of alternans in the heart, BCLstart, was measured in the absence of perturbations (δ=0 and was defined as the BCL at which 10% of LV exhibited alternans. The influences of perturbation size were investigated at two BCLs: one prior to BCLstart (BCLprior=BCLstart+20 ms and one preceding BCLprior (BCLfar=BCLstart+40 ms. Our results demonstrate significant spatial correlation of the region exhibiting alternans with smooth bifurcation characteristics, indicating that transition to alternans in isolated rabbit hearts occurs predominantly through smooth bifurcation.

  15. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    Directory of Open Access Journals (Sweden)

    Dian Ratri Wulandari

    2013-04-01

    Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

  16. Courtship in Frogs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 12. Courtship in Frogs Role of Acoustic Communication in Amphibian Courtship Behaviour. Debjani Roy. General Article Volume 1 Issue 12 December 1996 pp 39-48 ...

  17. Study of the correlation between the concentration of potassium in an extract of Aferontany and its biological effect on an isolated heart

    International Nuclear Information System (INIS)

    MANOELA, F.P.

    2005-01-01

    The objective of the present work is to determine the elemental quality of the extract of the malagasy medicinal plant, named Aferontany (Mollugo Nudicaulis), in particular the content of potassium in order to measure its contribution to cause heart hazardous. Decoction was used for plant extraction purposes. Total Refection X ray fluorescence analytical method was employed for the quantitative analysis. Organ isolated test method was applied to evaluate the impact of potassium in the extract on heart. The analytical results showed that Aferontany plant contains potassium (K), calcium (Ca), iron (Fe), titanium (Ti), zinc (Zn), manganese (Mn), rubidium (Rb), barium (Ba), strontium (Sr), copper (Cu) and lead (Pb).Their concentration varies with the collecting sites, the conservation duration, the age and the type of plant used organ. The potassium content of the plant is high and varies between 0.016 and 0.064%. The obtained results showed that the elemental concentrations in the decoction increase with the amount of used plant, the temperature and the duration. The concentration value of strontium is lower than 14 μg/L (MDL). The toxic elements concentrations measured in the decoction are low and in the order of 160 μg/L, 6.45 μg/L for the barium and the lead respectively (1g of decocted plant for 100 mL of water). The same decoction contains 5.59 mg/L of calcium, 346 μg/L of manganese 4.05 mg/L of Iron and 130 μg/L of copper. When using the ordinary posology, these elements do not present theoretically any problem on heart function. Besides, the decoction has 520 mg/L of potassium. This high content of potassium may cause heart problem. According to the experimentation carried out on the frog heart, cardiac stopping may occur if the potassium concentration value is in the order of 1100 mg/L. Therefore, The plant decoction would have mortal effect in the case of over uptake. Nevertheless, the intoxication is reversible [fr

  18. 31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

    International Nuclear Information System (INIS)

    Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

    2000-01-01

    ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

  19. NMR study of damage on isolated perfused rat heart exposed to ischemia and hypoxia

    International Nuclear Information System (INIS)

    Luo Xuechun; Yan Yongbin; Zhang Riqing; Fan Lili

    2001-01-01

    Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P-NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia

  20. Tissue specific phosphorylation of mitochondrial proteins isolated from rat liver, heart muscle, and skeletal muscle

    DEFF Research Database (Denmark)

    Bak, Steffen; León, Ileana R; Jensen, Ole Nørregaard

    2013-01-01

    -specific phosphorylation sites were identified in tissue-specific enzymes such as those encoded by HMGCS2, BDH1, PCK2, CPS1, and OTC in liver mitochondria, and CKMT2 and CPT1B in heart and skeletal muscle. Kinase prediction showed an important role for PKA and PKC in all tissues but also for proline-directed kinases......Phosphorylation of mitochondrial proteins in a variety of biological processes is increasingly being recognized and may contribute to the differences in function and energy demands observed in mitochondria from different tissues such as liver, heart, and skeletal muscle. Here, we used a combination...... of TiO2 phosphopeptide-enrichment, HILIC fractionation, and LC-MS/MS on isolated mitochondria to investigate the tissue-specific mitochondrial phosphoproteomes of rat liver, heart, and skeletal muscle. In total, we identified 899 phosphorylation sites in 354 different mitochondrial proteins including...

  1. Congenital heart defects in newborns with apparently isolated single gastrointestinal malformation: A retrospective study.

    Science.gov (United States)

    Schierz, Ingrid Anne Mandy; Pinello, Giuseppa; Giuffrè, Mario; La Placa, Simona; Piro, Ettore; Corsello, Giovanni

    2016-12-01

    Congenital gastrointestinal system malformations/abdominal wall defects (GISM) may appear as isolated defects (single or complex), or in association with multiple malformations. The high incidence of association of GISM and congenital heart defects (CHD) in patients with syndromes and malformative sequences is known, but less expected is the association of apparently isolated single GISM and CHD. The aim of this study was to investigate the frequency of CHD in newborns with isolated GISM, and the possibility to modify the diagnostic-therapeutic approach just before the onset of cardiac symptoms or complications. Anamnestic, clinical, and imaging data of newborns requiring abdominal surgery for GISM, between 2009 and 2014, were compared with a control group of healthy newborns. Distribution of GISM and cardiovascular abnormalities were analyzed, and risk factors for adverse outcomes were identified. Seventy-one newborns with isolated GISM were included in this study. More frequent GISM were intestinal rotation and fixation disorders. CHD were observed in 15.5% of patients, augmenting their risk for morbidity. Risk factors for morbidity related to sepsis were identified in central venous catheter, intestinal stoma, and H2-inhibitor-drugs. Moreover, 28.2% of newborns presented only functional cardiac disorders but an unexpectedly higher mortality. The high incidence of congenital heart disease in infants with apparently isolated GISM confirms the need to perform an echocardiographic study before surgery to improve perioperative management and prevent complications such as sepsis and endocarditis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Cardiac endothelial cells isolated from mouse heart - a novel model for radiobiology

    International Nuclear Information System (INIS)

    Jelonek, K.; Walaszczyk, A.; Gabrys, D.; Pietrowska, M.; Widlak, P.; Kanthou, Ch.

    2011-01-01

    Cardiovascular disease is recognized as an important clinical problem in radiotherapy and radiation protection. However, only few radiobiological models relevant for assessment of cardiotoxic effects of ionizing radiation are available. Here we describe the isolation of mouse primary cardiac endothelial cells, a possible target for cardiotoxic effects of radiation. Cells isolated from hearts of juvenile mice were cultured and irradiated in vitro. In addition, cells isolated from hearts of locally irradiated adult animals (up to 6 days after irradiation) were tested. A dose-dependent formation of histone γH 2 A.X foci was observed after in vitro irradiation of cultured cells. However, such cells were resistant to radiation-induced apoptosis. Increased levels of actin stress fibres were observed in the cytoplasm of cardiac endothelial cells irradiated in vitro or isolated from irradiated animals. A high dose of 16 Gy did not increase permeability to Dextran in monolayers formed by endothelial cells. Up-regulated expression of Vcam1, Sele and Hsp70i genes was detected after irradiation in vitro and in cells isolated few days after irradiation in vivo. The increased level of actin stress fibres and enhanced expression of stress-response genes in irradiated endothelial cells are potentially involved in cardiotoxic effects of ionizing radiation. (authors)

  3. Flow heterogeneity following global no-flow ischemia in isolated rabbit heart

    International Nuclear Information System (INIS)

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; Schustz, Amy M.; Kuo, Chaincy; Huesman, Michelle K.; Huesman, Ronald H.

    2002-01-01

    The purpose of this study was to evaluate flow heterogeneity and impaired reflow during reperfusion following 60 min global no-flow ischemia in the isolated rabbit heart. Radiolabeled microspheres were used to measure relative flow in small left ventricular (LV) segments in five ischemia + reperfused hearts and in five non-ischemic controls. Although variable in the post-ischemic hearts, flow heterogeneity was increased relative to pre-ischemia for the whole LV (0.92 plus or minus 0.41 vs. 0.37 plus or minus 0.07, P < 0.05) as well as the subendocardium (Endo) and subepicardium (Epi) considered separately (endo: 1.28 plus or minus 0.74 vs. 0.30 plus or minus 0.09; epi: 0.69 plus or minus 0.22 vs. 0.38 plus or minus 0.08; P < 0.05 for both comparisons) during early reperfusion. There were also segments with abnormally reduced reflow. The number of segments with abnormally reduced reflow increased as flow heterogeneity increased. Abnormally reduced reflow indicates that regional ischemia can persist despite restoration of normal global flow. In addition, the relationship between regional and global flow is altered and venous outflow is derived from regions with continued perfusion and not the whole LV. These observations emphasize the need to quantify regional reflow during reperfusion following sustained no-flow ischemia in the isolated rabbit heart

  4. Flow heterogeneity following global no-flow ischemia in isolated rabbit heart

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; Schustz, Amy M.; Kuo, Chaincy; Huesman, Michelle K.; Huesman, Ronald H.

    2003-02-01

    The purpose of this study was to evaluate flow heterogeneity and impaired reflow during reperfusion following 60 min global no-flow ischemia in the isolated rabbit heart. Radiolabeled microspheres were used to measure relative flow in small left ventricular (LV) segments in five ischemia + reperfused hearts and in five non-ischemic controls. Although variable in the post-ischemic hearts, flow heterogeneity was increased relative to pre-ischemia for the whole LV (0.92 plus or minus 0.41 vs. 0.37 plus or minus 0.07, P < 0.05) as well as the subendocardium (Endo) and subepicardium (Epi) considered separately (endo: 1.28 plus or minus 0.74 vs. 0.30 plus or minus 0.09; epi: 0.69 plus or minus 0.22 vs. 0.38 plus or minus 0.08; P < 0.05 for both comparisons) during early reperfusion. There were also segments with abnormally reduced reflow. The number of segments with abnormally reduced reflow increased as flow heterogeneity increased. Abnormally reduced reflow indicates that regional ischemia can persist despite restoration of normal global flow. In addition, the relationship between regional and global flow is altered and venous outflow is derived from regions with continued perfusion and not the whole LV. These observations emphasize the need to quantify regional reflow during reperfusion following sustained no-flow ischemia in the isolated rabbit heart.

  5. Compartment analysis of 125I-labelled albumin washout from coronary vessels of isolated perfused hearts

    International Nuclear Information System (INIS)

    Cheng Eap Ng; Seh-Hoon Song

    1978-01-01

    Albumin labelled with 125 I was used as a tracer to investigate the washout kinetics of plasma from the coronary circulation of isolated perfused feline hearts. Compartmentalization with experimental results showed at least two compartments. The model was compared with a three-compartment model found previously for red blood cells. The results indicate that there is a separation of plasma and RBC in the coronary microcirculation. (author)

  6. Eleutherodactylus frog introductions to Hawaii

    Science.gov (United States)

    Kraus, Fred; Campbell, Earl W.; Allison, Allen; Pratt, Thane K.

    1999-01-01

    As an oceanic archipelago isolated from continental source areas, Hawaii lacks native terrestrial reptiles and amphibians, Polynesians apparently introduced seven gecko and skink species after discovering the islands approximately 1500 years ago, and another 15 reptiles and five frogs have been introduced in the last century and a half (McKeown 1996). The Polynesian introductions are probably inadvertent because the species involved are known stowaway dispersers (Gibbons 1985; Dye and Steadman 1990), In contrast, most of the herpetological introductions since European contact with Hawaii have been intentional. Several frog species were released for biocontrol of insects (e.g., Dendrobates auratus, Bufo marinus, Rana rugosa, Bryan 1932; Oliver and Shaw 1953), and most of the remaining species are released or escaped pets (e.g., Phelsuma spp., Chamaeleo jacksonii, Iguana iguana, McKeown 1996), Government-approved releases have not occurred for many years, but the rate of establishment of new species has increased in the past few decades because of the importation and subsequent release of pets.

  7. Baltikinin: A New Myotropic Tryptophyllin-3 Peptide Isolated from the Skin Secretion of the Purple-Sided Leaf Frog, Phyllomedusa baltea

    Directory of Open Access Journals (Sweden)

    Daning Shi

    2016-07-01

    Full Text Available Here we report the identification of a novel tryptophyllin-3 peptide with arterial smooth muscle relaxation activity from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea. This new peptide was named baltikinin and had the following primary structure, pGluDKPFGPPPIYPV, as determined by tandem mass spectrometry (MS/MS fragmentation sequencing and from cloned skin precursor-encoding cDNA. A synthetic replicate of baltikinin was found to have a similar potency to bradykinin in relaxing arterial smooth muscle (half maximal effective concentration (EC50 is 7.2 nM. These data illustrate how amphibian skin secretions can continue to provide novel potent peptides that act through functional targets in mammalian tissues.

  8. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    OpenAIRE

    Haleh Vaez; Mehrban Samadzadeh; Fahimeh Zahednezhad; Moslem Najafi

    2012-01-01

    Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibra...

  9. Calcium uptake by sarcoplasmic reticulum isolated from hearts of septic rats

    International Nuclear Information System (INIS)

    McDonough, K.H.

    1988-01-01

    Myocardial sarcoplasmic reticulum (SR) plays a critical role in the regulation of the cytosolic calcium fluctuations that occur during the cardiac cycle. One function of the SR is to lower the calcium concentration so that myocardial relaxation and thus ventricular filling can occur. The aim of the present study was to determine if hyperdynamic sepsis induced a decrease in the capacity of SR to take up calcium. This defect would result in decreased ventricular filling and thus decreased cardiac output, as has previously been shown in isolated perfused working hearts removed from septic rats. Therefore, rats were anesthetized with ether, and sepsis was induced by the injection of an aliquot of a fecal homogenate into the peritoneal cavity. Control animals either underwent surgery and received an aliquot of sterilized fecal inoculum (sham) or were untreated (no surgery). On day 2 after surgery, animals were anesthetized with pentobarbital, and hearts were removed, weighted, and SR isolated. The rate of uptake of 45 Ca 2+ by SR from septic rats was not depressed compared to controls but in fact was elevated. Maximum 45 Ca 2+ accumulated by the SR and Ca 2+ -stimulated ATPase activity were similar in SR from control and septic hearts. These results suggest that the contractile dysfunction noted in the myocardium in early sepsis is probably not due to inadequate SR removal of Ca 2+ during diastole

  10. Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens.

    Science.gov (United States)

    Hovey, Kyle J; Seiter, Emily M; Johnson, Erin E; Saporito, Ralph A

    2018-03-01

    Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.

  11. Cardiovascular Activity of Labdane Diterpenes from Andrographis paniculata in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Khalijah Awang

    2012-01-01

    Full Text Available The dichloromethane (DCM extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5±3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5±11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1, 14-deoxy-11,12-didehydroandrographolide (2, 14-deoxyandrographolide (3, andrographolide (4, and neoandrographolide (5, were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2 and (3 were responsible for the coronary vasodilatation. This study also showed that andrographolide (4, the major labdane diterpene in this plant, has minimal effects on the heart.

  12. Cardiovascular Activity of Labdane Diterpenes from Andrographis paniculata in Isolated Rat Hearts

    Science.gov (United States)

    Awang, Khalijah; Abdullah, Nor Hayati; Hadi, A. Hamid A.; Su Fong, Yew

    2012-01-01

    The dichloromethane (DCM) extract of Andrographis paniculata Nees was tested for cardiovascular activity. The extract significantly reduced coronary perfusion pressure by up to 24.5 ± 3.0 mm Hg at a 3 mg dose and also reduced heart rate by up to 49.5 ± 11.4 beats/minute at this dose. Five labdane diterpenes, 14-deoxy-12-hydroxyandrographolide (1), 14-deoxy-11,12-didehydroandrographolide (2), 14-deoxyandrographolide (3), andrographolide (4), and neoandrographolide (5), were isolated from the aerial parts of this medicinal plant. Bioassay-guided studies using animal model showed that compounds, (2) and (3) were responsible for the coronary vasodilatation. This study also showed that andrographolide (4), the major labdane diterpene in this plant, has minimal effects on the heart. PMID:22536026

  13. Pulmonary hypertension and isolated right heart failure complicating amiodarone induced hyperthyroidism.

    Science.gov (United States)

    Wong, Sean-Man; Tse, Hung-Fat; Siu, Chung-Wah

    2012-03-01

    Hyperthyroidism is a common side effect encountered in patients prescribed long-term amiodarone therapy for cardiac arrhythmias. We previously studied 354 patients prescribed amiodarone in whom the occurrence of hyperthyroidism was associated with major adverse cardiovascular events including heart failure, myocardial infarction, ventricular arrhythmias, stroke and even death [1]. We now present a case of amiodarone-induced hyperthyroidism complicated by isolated right heart failure and pulmonary hypertension that resolved with treatment of hyperthyroidism. Detailed quantitative echocardiography enables improved understanding of the haemodynamic mechanisms underlying the condition. Copyright © 2011 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  14. Patient perceptions of experience with cardiac rehabilitation after isolated heart valve surgery

    DEFF Research Database (Denmark)

    Hansen, Tina B; Berg, Selina K; Sibilitz, Kirstine L

    2018-01-01

    in a cardiac rehabilitation programme, and none have analysed their experiences with it. AIMS: The purpose of this qualitative analysis was to gain insight into patients' experiences in cardiac rehabilitation, the CopenHeartVR trial. This trial specifically assesses patients undergoing isolated heart valve...... to take active personal responsibility for their health. Despite these benefits, participants experienced existential and psychological challenges and musculoskeletal problems. Participants also sought additional advice from healthcare professionals both inside and outside the healthcare system....... CONCLUSIONS: Even though the cardiac rehabilitation programme reduced insecurity and helped participants take active personal responsibility for their health, they experienced existential, psychological and physical challenges during recovery. The cardiac rehabilitation programme had several limitations...

  15. Chronic exposure to zinc oxide nanoparticles increases ischemic-reperfusion injuries in isolated rat hearts

    Energy Technology Data Exchange (ETDEWEB)

    Milivojević, Tamara; Drobne, Damjana; Romih, Tea; Mali, Lilijana Bizjak [University of Ljubljana, Department of Biology, Biotechnical Faculty (Slovenia); Marin, Irena; Lunder, Mojca; Drevenšek, Gorazd, E-mail: gorazd.drevensek@mf.uni-lj.si [University of Ljubljana, Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine (Slovenia)

    2016-10-15

    The use of zinc oxide nanoparticles (ZnO NPs) in numerous products is increasing, although possible negative implications of their long-term consumption are not known yet. Our aim was to evaluate the chronic, 6-week oral exposure to two different concentrations of ZnO NPs on isolated rat hearts exposed to ischemic-reperfusion injury and on small intestine morphology. Wistar rats of both sexes (n = 18) were randomly divided into three groups: (1) 4 mg/kg ZnO NPs, (2) 40 mg/kg ZnO NPs, and (3) control. After 6 weeks of treatment, the hearts were isolated, the left ventricular pressure (LVP), the coronary flow (CF), the duration of arrhythmias and the lactate dehydrogenase release rate (LDH) were measured. A histological investigation of the small intestine was performed. Chronic exposure to ZnO NPs acted cardiotoxic dose-dependently. ZnO NPs in dosage 40 mg/kg maximally decreased LVP (3.3-fold) and CF (2.5-fold) and increased the duration of ventricular tachycardia (all P < 0.01) compared to control, whereas ZnO NPs in dosage 4 mg/kg acted less cardiotoxic. Goblet cells in the small intestine epithelium of rats, treated with 40 mg ZnO NPs/kg, were enlarged, swollen and numerous, the intestinal epithelium width was increased. Unexpectedly, ZnO NPs in both dosages significantly decreased LDH. A 6-week oral exposure to ZnO NPs dose-dependently increased heart injuries and caused irritation of the intestinal mucosa. A prolonged exposure to ZnO NPs might cause functional damage to the heart even with exposures to the recommended daily doses, which should be tested in future studies.

  16. Congestive heart failure effects on atrial fibroblast phenotype: differences between freshly-isolated and cultured cells.

    Directory of Open Access Journals (Sweden)

    Kristin Dawson

    Full Text Available Fibroblasts are important in the atrial fibrillation (AF substrate resulting from congestive heart failure (CHF. We previously noted changes in in vivo indices of fibroblast function in a CHF dog model, but could not detect changes in isolated cells. This study assessed CHF-induced changes in the phenotype of fibroblasts freshly isolated from control versus CHF dogs, and examined effects of cell culture on these differences.Left-atrial fibroblasts were isolated from control and CHF dogs (ventricular tachypacing 240 bpm × 2 weeks. Freshly-isolated fibroblasts were compared to fibroblasts in primary culture. Extracellular-matrix (ECM gene-expression was assessed by qPCR, protein by Western blot, fibroblast morphology with immunocytochemistry, and K(+-current with patch-clamp. Freshly-isolated CHF fibroblasts had increased expression-levels of collagen-1 (10-fold, collagen-3 (5-fold, and fibronectin-1 (3-fold vs. control, along with increased cell diameter (13.4 ± 0.4 µm vs control 8.4 ± 0.3 µm and cell spreading (shape factor 0.81 ± 0.02 vs. control 0.87 ± 0.02, consistent with an activated phenotype. Freshly-isolated control fibroblasts displayed robust tetraethylammonium (TEA-sensitive K(+-currents that were strongly downregulated in CHF. The TEA-sensitive K(+-current differences between control and CHF fibroblasts were attenuated after 2-day culture and eliminated after 7 days. Similarly, cell-culture eliminated the ECM protein-expression and shape differences between control and CHF fibroblasts.Freshly-isolated CHF and control atrial fibroblasts display distinct ECM-gene and morphological differences consistent with in vivo pathology. Culture for as little as 48 hours activates fibroblasts and obscures the effects of CHF. These results demonstrate potentially-important atrial-fibroblast phenotype changes in CHF and emphasize the need for caution in relating properties of cultured fibroblasts to in vivo systems.

  17. Courtship in Frogs

    Indian Academy of Sciences (India)

    well-defined physical characteristics and a clear biological meaning. ... men t most successfully were the frogs and toads (hereafter referred ... Sound Pressure Level (SPL) in decibels = 20 loglOPt/Pr where,. Pt is the .... R.erythraea (left) and mean spectrum and sonagram of the female ... and egg laying activities initiated. 5.

  18. Acute effects of nandrolone decanoate on oxidative stress in isolated rat heart

    Directory of Open Access Journals (Sweden)

    Jevđević Maja

    2015-01-01

    Full Text Available Abuse of anabolic-androgenic steroids (AAS produces side effects in different tissues, with oxidative stress linked to their pathophysiology, being involved in fibrosis, cellular proliferation, and tumorigenesis. The aim of this study was to examine the acute effects of nandrolone decanoate (ND on oxidative stress in isolated rat heart. The hearts of male Wistar albino were excised and perfused according to the Langendorff technique at gradually increasing coronary perfusion pressures (40-120 cmH2O. The hearts were perfused with ND at doses of 1, 10 and 100 μM. Oxidative stress markers, including the index of lipid peroxidation (thiobarbituric acid reactive substances (TBARS, nitric oxide (nitrites; NO2-, the superoxide anion radical (O2- and hydrogen peroxide (H2O2 were measured in the coronary venous effluent. Our results showed that acute effects of ND do not promote the production of reactive oxygen species (ROS. Our finding pointed out that the highest concentration of ND may even possess some anti-oxidative potential, which should be examined further.

  19. Cardiac actions of phencyclidine in isolated guinea pig and rat heart: possible involvement of slow channels

    International Nuclear Information System (INIS)

    Temma, K.; Akera, T.; Ng, Y.C.

    1985-01-01

    The mechanisms responsible for the positive inotropic effect of phencyclidine were studied in isolated preparations of guinea pig and rat heart. In electrically paced left atrial muscle preparations, phencyclidine increased the force of contraction; rat heart muscle preparations were more sensitive than guinea pig heart muscle preparations. The positive inotropic effect of phencyclidine was not significantly reduced by a combination of phentolamine and nadolol; however, the effect was competitively blocked by verapamil in the presence of phentolamine and nadolol. Inhibition of the outward K+ current by tetraethylammonium chloride also produced a positive inotropic effect; however, the effect of tetraethylammonium was reduced by phentolamine and nadolol, and was almost insensitive to verapamil. The inotropic effect of phencyclidine was associated with a marked prolongation of the action potential duration and a decrease in maximal upstroke velocity of the action potential, with no change in the resting membrane potential. The specific [ 3 H]phencyclidine binding observed with membrane preparations from guinea pig ventricular muscle was saturable with a single class of high-affinity binding site. This binding was inhibited by verapamil, diltiazem, or nitrendipine, but not by ryanodine or tetrodotoxin. These results suggest that the positive inotropic effect of phencyclidine results from enhanced Ca 2+ influx via slow channels, either by stimulation of the channels or secondary to inhibition of outward K + currents

  20. Effects Of The Direct Renin Inhibitor Aliskiren On Oxidative Stress In Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Plecevic Sasa

    2015-09-01

    Full Text Available Increased activity of the renin-angiotensin-aldosterone system (RAAS plays a significant role in the development and progression of various cardio-metabolic diseases, such as hypertension, atherosclerosis and heart failure. Aliskiren is the newest antihypertensive drug and the first orally active direct renin inhibitor to become available for clinical use. This study investigated the acute and direct effects of Aliskiren on different parameters of oxidative stress on isolated rat heart. The hearts of male Wistar albino rats (n = 24, 8 per experimental group, age 8 weeks, body mass 180–200 g, were excised and retrogradely perfused according to the Langendorfftechnique at a gradually increasing perfusion pressure (40-120 cmH2O. Markers of oxidative stress (NO2−, TBARS, H2O2 and O2− were measured spectrophotometrically after perfusion with three different concentrations of Aliskiren (0.1 μM, 1 μM, and 10 μM. The results demonstrated possible dose-dependent cardioprotective properties of Aliskiren, particularly with higher CPP. Lipid peroxidation (TBARS levels decreased with the highest dose of Aliskiren and higher CPP, and the same trend was observed in nitrite (NO2− and hydrogen peroxide (H2O2 levels. These findings indicate that the acute effects of Aliskiren do not likely promote the production of reactive oxygen species upon higher pressure with the highest dose. Aliskiren may exert beneficial effects on oxidative stress biomarkers.

  1. Measurement of the efficacy of 2% lipid in reversing bupivacaine- induced asystole in isolated rat hearts

    Science.gov (United States)

    2014-01-01

    Background The reversal efficacy of 2% lipid emulsion in cardiac asystole induced by different concentrations of bupivacaine is poorly defined and needs to be determined. Methods Forty-two male Sprague–Dawley rats were randomly divided into seven groups: B40, B60, B80, B100, B120, B140 and B160, n = 6. The Langendorff isolated heart perfusion model was used, which consisted of a balanced perfusion with Krebs-Henseleit solution for 25 minutes and a continuous infusion of 100 μmol/L bupivacaine until asystole had been induced for 3 minutes. The hearts in the seven groups were perfused with Krebs-Henseleit solution containing a 2% lipid emulsion, and 40, 60, 80, 100, 120, 140 or 160 μmol/L bupivacaine, respectively. Cardiac recovery was defined as a spontaneous and regular rhythm with a rate-pressure product > 10% of the baseline value for more than 1 minute. Our primary outcome was the rate-pressure product 25 minutes after cardiac recovery. Other cardiac function parameters were also recorded. Results All groups demonstrated cardiac recovery. During the recovery phase, heart rate, rate-pressure product, the maximum left ventricular pressure rise and decline in heart rate in the B120-B160 groups was significantly lower than those in the B40-B80 groups (P bupivacaine and the reversal effects of a 2% lipid emulsion showed a typical transoid S-shaped curve, R2 = 0.9983, IC50 value was 102.5 μmol/L (95% CI: 92.44 - 113.6). Conclusions There is a concentration-response relationship between the concentrations of bupivacaine and the reversal effects of 2% lipid emulsion. PMID:25089118

  2. Functional response of white rats isolated heart to the stimulation of adrenergic receptors after gamma-irradiation in low doses

    International Nuclear Information System (INIS)

    Antonenko, A.N.; Lobanok, L.M.

    1999-01-01

    It was investigated the effects of acute gamma-irradiation on bio mechanical activity of rats heart isolated by Langendorf's method in early and delayed terms after exposure to gamma-rays. Intra ventricle pressure and the rate of its growth, volumetric rate of coronal flow, frequency of heart contraction were registered. Stimulation of alpha-adrenergic receptors was conducted by means of specific agonist mesatone and stimulation of beta-adrenergic receptors was made by means of isoprenaline. The study has shown that acute irradiation of rats caused the decrease of both contractile ability and relaxation of myocardium in a 10 days after exposure. In delayed period bio mechanical activity of isolated heart was restored. Functional response of heart to the stimulation of alpha- and beta-adrenergic receptors was decreased in all terms of investigation

  3. Seasonal variations of anti-/apoptotic and antioxidant proteins in the heart and gastrocnemius muscle of the water frog Pelophylax ridibundus.

    Science.gov (United States)

    Feidantsis, Konstantinos; Anestis, Andreas; Michaelidis, Basile

    2013-10-01

    In the present work we investigated the seasonal variations of apoptotic and antioxidant proteins in the heart and gastrocnemius muscle of the amphibian Pelophylax ridibundus. Particularly processes studied included the evaluation of hypoxia through the levels of transcriptional factor Hif-1α, of apoptosis through the determination of Bcl-2 and Bax, ubiquitin conjugates levels and the antioxidant defense through the determination of the activity of enzymes such as superoxide dismutase, catalase and glutathione peroxidase. Due to a general metabolic depression during overwintering, levels of the above mentioned proteins and enzymes are generally retained at low levels of expression and activity in the examined tissues of P. ridibundus. On the other hand recovery from overwintering induces oxidative stress, followed by increased levels of the specific proteins and enzymes. A milder up-regulation of antioxidant enzymes during overwintering probably prepares P. ridibundus for oxidative stress during arousal. The seasonal activation of these mechanisms seems to protect this species from these unfavourable conditions. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Exposure to chronic isolation modulates receptors mRNAs for oxytocin and vasopressin in the hypothalamus and heart.

    Science.gov (United States)

    Pournajafi-Nazarloo, Hossein; Kenkel, William; Mohsenpour, Seyed Ramezan; Sanzenbacher, Lisa; Saadat, Habibollah; Partoo, Leila; Yee, Jason; Azizi, Fereidoun; Carter, C Sue

    2013-05-01

    The goal of our study was to explore the effect of social isolation stress of varying durations on the plasma oxytocin (OT), messenger ribonucleic acid (mRNA) for oxytocin receptor (OTR), plasma arginine vasopressin (AVP) and mRNA for V1a receptor of AVP (V1aR) expression in the hypothalamus and heart of socially monogamous female and male prairie voles (Microtus ochrogaster). Continuous isolation for 4 weeks (chronic isolation) increased plasma OT level in females, but not in males. One hour of isolation every day for 4 weeks (repeated isolation) was followed by a significant increase in plasma AVP level. Chronic isolation, but not repeated isolation, significantly decreased OTR mRNA in the hypothalamus and heart in both sexes. Chronic isolation significantly decreased cardiac V1aR mRNA, but no effect on hypothalamic V1aR mRNA expression. We did not find a gender difference within repeated social isolation groups. The results of the present study reveal that although chronic social isolation can down-regulate gene expression for the OTR in both sexes, the release of the OT peptide was increased after chronic isolation only in females, possibly somewhat protecting females from the negative consequences of isolation. In both sexes repeated, but not chronic, isolation increased plasma AVP, which could be permissive for mobilization and thus adaptive in response to a repeated stressor. The differential effects of isolation on OT and AVP systems may help in understanding mechanisms through social interactions can be protective against emotional and cardiovascular disorders. Published by Elsevier Inc.

  5. beta-Methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart.

    Science.gov (United States)

    DeGrado, T R; Holden, J E; Ng, C K; Raffel, D M; Gatley, S J

    1989-01-01

    The use of 15-p-iodophenyl-beta-methyl-pentadecanoic acid (beta Me-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both beta Me-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). In contrast, beta Me-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond beta Me-IPPA-CoA in the oxidative pathway.

  6. β-methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart

    International Nuclear Information System (INIS)

    DeGrado, T.R.; Holden, J.E.; Ng, C.K.; Raffel, D.M.; Gatley, S.J.

    1989-01-01

    The use of 15-p-iodophenyl-β-methyl-pentadecanoic acid (βMe-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both βMe-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). In contrast, βMe-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond βMe-IPPA-CoA in the oxidative pathway. (orig.)

  7. beta. -methyl-15-p-iodophenylpentadecanoic acid metabolism and kinetics in the isolated rat heart

    Energy Technology Data Exchange (ETDEWEB)

    DeGrado, T.R.; Holden, J.E.; Ng, C.K.; Raffel, D.M.; Gatley, S.J.

    1989-02-01

    The use of 15-p-iodophenyl-..beta..-methyl-pentadecanoic acid (..beta..Me-IPPA) as an indicator of long chain fatty acid (LCFA) utilization in nuclear medicine studies was evaluated in the isolated, perfused, working rat heart. Time courses of radioactivity (residue curves) were obtained following bolus injections of both ..beta..Me-IPPA and its straight chain counterpart 15-p-iodophenyl-pentadecanoic acid (IPPA). IPPA kinetics clearly indicated flow independent impairment of fatty acid oxidation caused by the carnitine palmitoyltransferase I inhibitor 2(5(4-chlorophenyl)pentyl)oxirane-2-carboxylate (POCA). In contrast, ..beta..Me-IPPA kinetics were insensitive to changes in fatty acid oxidation rate and net utilization of long chain fatty acid. Analysis of radiolabeled species in coronary effluent and heart homogenates showed the methylated fatty acid to be readily incorporated into complex lipids but a poor substrate for oxidation. POCA did not significantly alter metabolism of the tracer, suggesting that the tracer is poorly metabolized beyond ..beta..Me-IPPA-CoA in the oxidative pathway.

  8. Analyzing the electrophysiological effects of local epicardial temperature in experimental studies with isolated hearts

    International Nuclear Information System (INIS)

    Tormos, Alvaro; Millet, José; Guill, Antonio; Chorro, Francisco J; Cánoves, Joaquín; Mainar, Luis; Such, Luis; Alberola, Antonio; Trapero, Isabel; Such-Miquel, Luis

    2008-01-01

    As a result of their modulating effects upon myocardial electrophysiology, both hypo- and hyperthermia can be used to study the mechanisms that generate or sustain cardiac arrhythmias. The present study describes an original electrode developed with thick-film technology and capable of controlling regional temperature variations in the epicardium while simultaneously registering its electrical activity. In this way, it is possible to measure electrophysiological parameters of the heart at different temperatures. The results obtained with this device in a study with isolated and perfused rabbit hearts are reported. An exploration has been made of the effects of local temperature changes upon the electrophysiological parameters implicated in myocardial conduction. Likewise, an analysis has been made of the influence of local temperature upon ventricular fibrillation activation frequency. It is concluded that both regional hypo- and hyperthermia exert reversible and opposite effects upon myocardial refractoriness and conduction velocity in the altered zone. The ventricular activation wavelength determined during constant pacing at 250 ms cycles is not significantly modified, however. During ventricular fibrillation, the changes in the fibrillatory frequency do not seem to be transmitted to normal temperature zones

  9. Correlation between Amitriptyline-Induced Cardiotoxic Effects and Cardiac S100b Protein in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Nil Hocaoğlu

    2016-12-01

    Full Text Available Background: Amitriptyline is an important cause of mortality due to its cardiovascular toxicity. Aims: To investigate the changes in levels of cardiac S100b protein on amitriptyline-induced cardiotoxicity and also to examine the correlation between amitriptyline-induced cardiotoxic effects and cardiac S100b protein in an isolated rat heart model. Study Design: Animal experimentation, isolated heart model. Methods: After a stabilization period, isolated hearts were randomized to two groups (n=5 and n=7. In the control group, isolated hearts were subjected to an infusion of 5% dextrose for 60 minutes. In the amitriptyline group, 5.5×10-5 M amitriptyline was infused for 60 minutes to achieve amitriptyline toxicity. After the infusion period, heart tissues were removed for histological examination. Results: In comparison to control treatment, amitriptyline infusion decreased left ventricular developed pressure (LVDP, dp/dtmax and heart rate (HR and significantly prolonged QRS duration (p<0.05. The semiquantitative scores for S100b protein levels in amitriptyline-infused hearts were higher than in the control group (p<0.01. At the end of the experiment, in the amitriptyline-infused group, significant correlations were found between LVDP and S100b protein scores (r=-0.807, p=0.003 and between QRS duration and S100b protein scores (r=0.859, p=0.001. Conclusion: Our results indicate that the S100b protein may be a helpful indicator or biomarker in studying the cardiotoxic effects of amitriptyline.

  10. Ranavirus in wild edible frogs Pelophylax kl. esculentus in Denmark

    DEFF Research Database (Denmark)

    Ariel, Ellen; Kielgast, Jos; Svart, Hans Erik

    2009-01-01

    interviewed by phone and 10 cases were examined on suspicion of diseaseinduced mortality. All samples were negative for Bd. Ranavirus was isolated from 2 samples of recently dead frogs collected during a mass mortality event in an artificial pond near Slagelse, Denmark. The identity of the virus was confirmed...

  11. Dietary manipulation and social isolation alter disease progression in a murine model of coronary heart disease.

    Directory of Open Access Journals (Sweden)

    Yumiko Nakagawa-Toyama

    Full Text Available BACKGROUND: Mice with a deficiency in the HDL receptor SR-BI and low expression of a modified apolipoprotein E gene (SR-BI KO/ApoeR61(h/h called 'HypoE' when fed an atherogenic, 'Paigen' diet develop occlusive, atherosclerotic coronary arterial disease (CHD, myocardial infarctions (MI, and heart dysfunction and die prematurely (50% mortality ~40 days after initiation of this diet. Because few murine models share with HypoE mice these cardinal, human-like, features of CHD, HypoE mice represent a novel, small animal, diet-inducible and genetically tractable model for CHD. To better describe the properties of this model, we have explored the effects of varying the composition and timing of administration of atherogenic diets, as well as social isolation vs. group housing, on these animals. METHODOLOGY/PRINCIPAL FINDINGS: HypoE mice were maintained on a standard lab chow diet (control until two months of age. Subsequently they received one of three atherogenic diets (Paigen, Paigen without cholate, Western or control diet for varying times and were housed in groups or singly, and we determined the plasma cholesterol levels, extent of cardiomegaly and/or survival. The rate of disease progression could be reduced by lowering the severity of the atherogenic diet and accelerated by social isolation. Disease could be induced by Paigen diets either containing or free of cholate. We also established conditions under which CHD could be initiated by an atherogenic diet and then subsequently, by replacing this diet with standard lab chow, hypercholesterolemia could be reduced and progression to early death prevented. CONCLUSIONS/SIGNIFICANCE: HypoE mice provide a powerful, surgery-free, diet-'titratable' small animal model that can be used to study the onset of recovery from occlusive, atherosclerotic CHD and heart failure due to MI. HypoE mice can be used for the analysis of the effects of environment (diet, social isolation on a variety of features of

  12. The influence of Poly-Vinyl-Chloride tubing on the isolated perfused rat´s heart.

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1950-01-01

    There are types of poly-vinyl-chloride tubing sold and used for medical and biological purposes which deteriorate heart action in a few minutes. A simple method for testing P.V.C. tubing can be found in the isolated rat's he art perfused according to Langendorff.

  13. The effect of adrenaline and high Ca2+ on the mechanical performance and oxygen consumption of the isolated perfused trout (Oncorhynchus mykiss) heart

    DEFF Research Database (Denmark)

    Rytter, Dorte; Gesser, Hans

    2007-01-01

    In heart muscle from mammals, catecholamines frequently evoke an oxygen waste and reduce efficiency. It was examined if this also applies to fish in which heart muscle activity is often restricted by oxygen availability. In the isolated perfused heart from rainbow trout, adrenaline (0.5 micro...

  14. Snoring puddle frog

    International Nuclear Information System (INIS)

    Lloyd, Mark Anthony

    2000-01-01

    Full text: The purpose of this paper is to hold a biological mirror in front of ourselves, the nuclear energy community, and to suggest that the reflection we will see there will help us both professionally and as members of a broader society. Let us start with sex. For sex to function as a means of reproduction, a male and a female of a particular species have to recognise each other and mate. The important terms here are 'particular species' and 'recognise'. Within most species, extraordinarily precise mate recognition systems have evolved. The precise frequency of the croak of a particular species of frog; the precise seasonal coloration of a particular species of salmon; the precise length of the tail of a particular species of bird; each is recognisable instantly to a prospective mate, though not to untrained human ears or eyes. 'The Recognition Concept of Species' (1985) is a monograph that has become something of a 'classic' in annals of evolutionary biology. Its author, HEH Paterson, suggests that a species can be defined as a group of organisms that share a common mate recognition system. Mating is an exchange of genes, and creatures that do not recognise each other do not exchange genes. A mate recognition system closes off the gene pool and may increasingly isolate its participants from even their nearest relatives. Biological evolution has numerous links and parallels with the evolution of human cultures. Some of our recognition systems seem to have a knack for drawing everyone in - American popular culture, for example, is now inescapable. Other recognition systems repel all but a few - take, or rather don't take, the Hell's Angels or the Ku Klux Klan. We, as members of the nuclear energy culture, are members of a closed and even repellent gene pool. We share a recognition system by which we perpetuate ourselves from generation to generation, from Hiroshima to Chernobyl. Outsiders do not understand our language: terms like 'credit for fission products

  15. Lithobates sylvaticus (wood frog)

    Science.gov (United States)

    Fuller, Pam

    2016-01-01

    A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

  16. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

    Science.gov (United States)

    de Sá, Fábio P; Zina, Juliana; Haddad, Célio F B

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

  17. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

    Directory of Open Access Journals (Sweden)

    Fábio P de Sá

    Full Text Available Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids, we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

  18. Assessment of Cardiovascular Apoptosis in the Isolated Rat Heart by Magnetic Resonance Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Hiller

    2006-04-01

    Full Text Available Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart. Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA-coated liposomes. The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T1 and T2* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.

  19. Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model

    Directory of Open Access Journals (Sweden)

    Esterhuyse Adriaan J

    2010-06-01

    Full Text Available Abstract Background and Aims Recent studies have shown that dietary red palm oil (RPO supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2 activation and PKB/Akt phosphorylation were also investigated. Materials and methods Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC, a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO, for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography. Results Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% versus 30.2 ± 3.9% and 27.1 ± 2.4% respectively. Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308 was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation. Conclusions Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in

  20. Distribution, structure and projections of the frog intracardiac neurons.

    Science.gov (United States)

    Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

    2012-05-21

    Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Oxygen consumption and heart rate responses to isolated ballet exercise sets.

    Science.gov (United States)

    Rodrigues-Krause, Josianne; Dos Santos Cunha, Giovani; Alberton, Cristine Lima; Follmer, Bruno; Krause, Mauricio; Reischak-Oliveira, Alvaro

    2014-01-01

    Ballet stage performances are associated with higher cardiorespiratory demand than rehearsals and classes. Hence, new interest is emerging to create periodized training that enhances dancers' fitness while minimizing delayed exercise-induced fatigue and possible injuries. Finding out in what zones of intensity dancers work during different ballet movements may support the use of supplemental training adjusted to the needs of the individual dancer. Therefore, the main purpose of this study was to describe dancers' oxygen consumption (VO2) and heart rate (HR) responses during the performance of nine isolated ballet exercise sets, as correlated with their first and second ventilatory thresholds (VT1 and VT2). Twelve female ballet dancers volunteered for the study. Their maximum oxygen consumption (VO2max), VT1, and VT2 were determined by use of an incremental treadmill test. Nine sets of ballet movements were assessed: pliés, tendus, jetés, rond de jambes, fondus, grand adage (adage), grand battements, temps levés, and sautés. The sets were randomly executed and separated by 5 minute rest periods. ANOVA for repeated measurements followed by the Bonferroni Post-hoc test were applied (p ballet sets. This stratification followed closely, but not exactly, the variation in HR. For example, rond de jambes (156.8 ± 19 b·min(-1)) did not show any significant difference from all the other ballet sets, nor VT1 or VT2. It is concluded that the workloads of isolated ballet sets, based on VO2 responses, vary between low and moderate aerobic intensity in relation to dancers' VT1 and VT2. However, ballet set workloads may be higher when based on HR responses, due to the intermittent and isometric components of dance.

  2. The Effects Of L-Arginine And L-Name On Coronary Flow And Oxidative Stress In Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Sobot Tanja

    2015-12-01

    Full Text Available The aim of this experimental study was to assess the effects of the acute administration of L-arginine alone and in combination with L-NAME (a non-selective NO synthase inhibitor on the coronary flow and oxidative stress markers in isolated rat hearts. The experimental study was performed on hearts isolated from Wistar albino rats (n=12, male, 8 weeks old, body mass of 180-200 g. Retrograde perfusion of the isolated preparations was performed using a modified method according to the Langendorff technique with a gradual increase in the perfusion pressure (40–120 cmH2O. The following values were measured in the collected coronary effluents: coronary flow, released nitrites (NO production marker, superoxide anion radical and the index of lipid peroxidation (measured as thiobarbiturate reactive substances. The experimental protocol was performed under controlled conditions, followed by the administration of L-arginine alone (1 mmol and L-arginine (1 mmol + L-NAME (30 μmol. The results indicated that L-arginine did not significantly increase the coronary flow or the release of NO, TBARS and the superoxide anion radical. These effects were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive effect. Hence, the results of our study do not demonstrate significant effects of L-arginine administration on the coronary flow and oxidative stress markers in isolated rat hearts.

  3. The effect of rigor mortis on the passage of erythrocytes and fluid through the myocardium of isolated dog hearts.

    Science.gov (United States)

    Nevalainen, T J; Gavin, J B; Seelye, R N; Whitehouse, S; Donnell, M

    1978-07-01

    The effect of normal and artificially induced rigor mortis on the vascular passage of erythrocytes and fluid through isolated dog hearts was studied. Increased rigidity of 6-mm thick transmural sections through the centre of the posterior papillary muscle was used as an indication of rigor. The perfusibility of the myocardium was tested by injecting 10 ml of 1% sodium fluorescein in Hanks solution into the circumflex branch of the left coronary artery. In prerigor hearts (20 minute incubation) fluorescein perfused the myocardium evenly whether or not it was preceded by an injection of 10 ml of heparinized dog blood. Rigor mortis developed in all hearts after 90 minutes incubation or within 20 minutes of perfusing the heart with 50 ml of 5 mM iodoacetate in Hanks solution. Fluorescein injected into hearts in rigor did not enter the posterior papillary muscle and adjacent subendocardium whether or not it was preceded by heparinized blood. Thus the vascular occlusion caused by rigor in the dog heart appears to be so effective that it prevents flow into the subendocardium of small soluble ions such as fluorescein.

  4. Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

    International Nuclear Information System (INIS)

    Hicks, M.; Du, Z.Y.; Spratt, P.; Macdonald, P.

    1998-01-01

    The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 μM pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 μM); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H 2 O. The system was then converted to 'working mode' by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H 2 O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context

  5. Enhanced preservation of the isolated rat heart after hypothermic storage by pinacidil pretreatment and storage in lazaroid U74500A

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, M. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Division of Clinical Pharmacology and Toxicology; Du, Z.Y.; Spratt, P.; Macdonald, P. [St Vincent`s Hospital, Darlinghurst, NSW (Australia). Cardiopulmonary Transplant Unit

    1998-12-31

    The aim of the present study was to compare 3 protocols incorporating these approaches on the preservation of haemodynamic function in the isolated working rat heart after hypothermic storage. These protocols were: 1) pretreatment of the heart with 200 {mu}M pinacidil, an ATP-sensitive potassium channel opener; 2) storage in cardioplegic solution containing the lipid soluble lazaroid antioxidant U74500A (30 {mu}M); 3) A combination of protocols 1 and 2. Methods: Hearts from Wistar rats (250 to 330g body weight) were perfused on a Langendorff apparatus. Each heart was ligated to an aortic cannula and perfused retrogradely, with oxygenated Krebs solution at a hydrostatic pressure of 100 cm H{sub 2}O. The system was then converted to `working mode` by switching the perfusate from aorta to a left atrial cannula (filling pressure 15 cm H{sub 2}O). After stabilisation, the following pre-arrest indices of cardiac function were recorded: heart rate (HR), coronary flow (CF), aortic flow (AF) and cardiac output (CO). Hearts were then randomised to protocols 1-3, untreated controls or vehicle treated controls (n=6 animals/ group). Hearts were stored in an extracellular-based preservation solution for 12 hours at 2-3degC, remounted on the perfusion apparatus and stabilised as before. Haemodynamic measurements were then repeated. Conclusions: Combined pharmacological activation of ATP-sensitive potassium channels before cardioplegia and the addition of U74500A to the preservation solution is associated with a significantly enhanced haemodynamic function in the rat heart after 12 hours of hypothermic storage. These data suggest a novel use for these agents in the transplantation context Truncated abstract. 1 tab.

  6. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  7. Isolated persistent left-sided superior vena cava, giant coronary sinus, atrial tachycardia and heart failure in a child

    Directory of Open Access Journals (Sweden)

    Nagaraja Moorthy

    2013-09-01

    Full Text Available Persistence of a left-sided superior vena cava (PLSVC with absent right superior vena cava (isolated PLSVC is a very rare venous malformation and commonly associated with congenital heart disease or alterations of the cardiac situs. We describe an unusual case of a young boy presenting with persistent atrial tachycardia and congestive heart failure. He was detected to have unexplained grossly dilated right atrium, right ventricle with systolic dysfunction and a giant coronary sinus (CS. The dilated CS closely mimicked a pseudo cor-triatriatum on echocardiography. Contrast echocardiography from both arms revealed opacification of the CS before the right atrium. Bilateral upper limb venography confirmed the presence of absent right SVC and isolated persistent left SVC draining into the giant coronary sinus.

  8. The role of K –ATP channel in the preconditioning effect of magnesium in the rat isolated heart

    Directory of Open Access Journals (Sweden)

    Bazargan M.

    2007-05-01

    Full Text Available There is growing interest for beneficial effect of Mg in the cardiovascular disorders. A number of cardiovascular disorders including myocardial infarction, arrhythmias and congestive heart failure have been associated with low extracellular or intracellular concentrations of Mg. The aim of present study was to investigate the preconditioning effects of magnesium (Mg on cardiac function and infarct size in the globally ischemic-reperfusion in isolated rat heart. Rat hearts were Langendorff-perfused, subjected to 30 minutes of global ischemia and 90 minutes of reperfusion, and assigned to one of the following treatment groups with 7 hearts in each group: (1 control, (2 ischemic- reperfusion, (IR, (3 ischemic preconditioning, (IPC of 5 minutes of global ischemia - reperfusion before lethal ischemia; or pretreatment with (4 30 µmol/L of Diazoxide (Dia, (5 8 mmol/L magnesium, (6 10 µmol/L glibenclamid (Gli, (7 magnesium and Dia and (8 magnesium and Gli. Infarct size was measured by the triphenyltetrazolium chloride method. Left ventricular function was assessed by left ventricular developed pressure (LVDP, heart rate and coronary flow (CF. Mg limited infarct size (9.76 % vs 44.47% in IR, P< 0.001 as did Dia (10.2 % vs 44.4 % in IR P< 0.001 and IPC (8.69 % vs 44.47% in IR, P< 0.001. The protective effect of magnesium was abolished by Gli. Administration of Mg had an anti-infarct effect in ischemic-reperfusion isolated rat hearts and improved cardiac function. Blockade of K-ATP channel abolished the protective effects of magnesium and suggest that K-ATP channel has an important role in this effects.

  9. Development of an Assay Based on the Effects of PGBx on the Isolated Perfused Rat Heart and Rat Skeletal Muscle.

    Science.gov (United States)

    1980-09-01

    had no effect on discphe- nol induced alterations in spontaneous heart rate, but did appear to prevent the increase in coronary flow caused by...Phosphorylase a i -24 activity was also the same in each of the groups examined (Table 2-4). DISCUSSION The ability of PGBx to prevent 2,4-dinitrophenol-induced...euthyroid and hyperthyroid rats. Eur. J. Pharmac. 19, 12-17. Aronson, C. E. and Serlick, E. R. (1977a) Effects of chlorpromazine on the isolated

  10. Models of torsades de pointes: effects of FPL64176, DPI201106, dofetilide, and chromanol 293B in isolated rabbit and guinea pig hearts.

    Science.gov (United States)

    Cheng, Hsien C; Incardona, Josephine

    2009-01-01

    For studying the torsades de pointes (TdP) liability of a compound, most high and medium throughput methods use surrogate markers such as HERG inhibition and QT prolongation. In this study, we have tested whether isolated hearts may be modified to allow TdP to be the direct readout. Isolated spontaneously beating rabbit and guinea pig hearts were perfused according to the Langendorff method in hypokalemic (2.1 mM) solution. The in vitro lead II ECG equivalent and the incidence of TdP were monitored for 1 h. In addition, heart rate, QTc, Tp-Te, short-term variability (STV), time to arrhythmia, and time to TdP were also analyzed. FPL64176, a calcium channel activator; and DPI201106, a sodium channel inactivation inhibitor, produced TdP in isolated rabbit and guinea pig hearts in a concentration dependent manner; guinea pig hearts were 3- to 5-fold more sensitive than rabbit hearts. Both compounds also increased QTc and STV. In contrast, dofetilide, an IKr inhibitor, produced no (or a low incidence of) TdP in both species, in spite of prolongation of QTc intervals. Chromanol 293B, an IKs inhibitor, did not produce TdP in rabbit hearts but elicited TdP concentration dependently in guinea pig hearts even though the compound had no effect on QTc intervals. IKs inhibition appears to be more likely to produce TdP in isolated guinea pig hearts than IKr inhibition. Chromanol 293B did not produce TdP in rabbit hearts presumably due to a low level of IKs channels in the heart. TdP produced in this study was consistent with the notion that its production was a consequence of reduced repolarization reserve, thereby causing rhythmic abnormalities. This isolated, perfused, and spontaneously beating rabbit and guinea pig heart preparation in hypokalemic medium may be useful as a preclinical test model for studying proarrhythmic liability of compounds in new drug development.

  11. Epicardial excitation pattern as observed in the isolated revived and perfused fetal human heart

    NARCIS (Netherlands)

    Durrer, D.; Büller, J.; Graaff, P.; Lo, G.I.; Meijler, F.L.

    1961-01-01

    The resuscitated fetal human heart can be used as an experimental tooI for the investigation of the excitatory process in the human heart. During perfusion the configuration of the epicardial electrocardiograms does not change appreciably. For accurate recording permitting a detailed analysis, the

  12. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    Science.gov (United States)

    Vaez, Haleh; Samadzadeh, Mehrban; Zahednezhad, Fahimeh; Najafi, Moslem

    2012-01-01

    Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H) solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2%) for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (Phoney. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2%) markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (Phoney in global ischemia showed protective effects against ischemia/reperfusion (I/R) injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects. PMID:24312792

  13. Protectant activity of defibrotide in cardioplegia followed by ischemia/reperfusion injury in the isolated rat heart.

    Science.gov (United States)

    Rossoni, G; Pompilio, G; Biglioli, P; Alamanni, F; Tartara, P; Rona, P; Porqueddu, M; Berti, F

    1999-01-01

    Previous studies have shown that defibrotide, a polydeoxyribonucleotide obtained by depolymerization of DNA from porcine tissues, has important protective effects on myocardial ischemia, which may be associated with a prostacyclin-related mechanism. The purpose of this study was to investigate the direct effects of defibrotide (given in cardioplegia or after ischemia) on a model of rat heart recovery after cardioplegia followed by ischemia/reperfusion injury. Isolated rat hearts, undergoing 5 minutes of warm cardioplegic arrest followed by 20 minutes of global ischemia and 30 minutes of reperfusion, were studied using the modified Langendorff model. The cardioplegia consisted of St. Thomas' Hospital solution augmented with defibrotide (50, 100, and 200 microg/mL) or without defibrotide (controls). Left ventricular mechanical function and the levels of creatine kinase, lactate dehydrogenase, and 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha; the stable metabolite of prostacyclin) were measured during preischemic and reperfusion periods. After global ischemia, hearts receiving defibrotide in the cardioplegic solution (n = 8) manifested in a concentration-dependent fashion lower left ventricular end-diastolic pressure (p defibrotide in the cardioplegic solution also had, in a dose-dependent way, lower levels of creatine-kinase (p defibrotide was given alone to the hearts at the beginning of reperfusion (n = 7), the recovery of postischemic left ventricular function was inferior (p defibrotide was given in cardioplegia. Defibrotide confers to conventional crystalloid cardioplegia a potent concentration-dependent protective effect on the recovery of isolated rat heart undergoing ischemia/reperfusion injury. The low cost and the absence of contraindications (cardiac toxicity and hemodynamic effects) make defibrotide a promising augmentation to cardioplegia.

  14. Main alkaloids from the Brazilian dendrobatidae frog Epipedobates flavopictus: pumiliotoxin 251D, histrionicotoxin and decahydroquinolines.

    Science.gov (United States)

    Mortari, Márcia Renata; Schwartz, Elisabeth N Ferroni; Schwartz, Carlos Alberto; Pires, Osmindo Rodrigues; Santos, Marcello Moreira; Bloch, Carlos; Sebben, Antonio

    2004-03-01

    Epipedobates flavopictus, Dendrobatidae, is a small aposematic frog found in Brazilian Cerrado bioma. In the present work, we isolated and characterized chemically the most abundant alkaloids present in the cutaneous extract of E. flavopictus. The specimens were collected in Pirenópolis (Goiás, Brazil), their skins were removed and extracted with methanol, and submitted to purification by HPLC and identification by gas chromatography and mass spectrometry. Pumiliotoxin 251D, histrionicotoxin 285Da and two decahydroquinolines, 219A and 243A, were identified. The pumiliotoxin 251D was tested on isolated frog sciatic nerve and on isolated guinea pig ileum muscle. The pumiliotoxin 251D slightly reduced the action potentials amplitude of frog sciatic nerve. The crude skin extract of E. flavopictus and the pumiliotoxin 251D produced rhythmic contractions and increased the muscular tension on isolated guinea pig ileum.

  15. Myocardial Creatine Levels Do Not Influence Response to Acute Oxidative Stress in Isolated Perfused Heart

    Science.gov (United States)

    Aksentijević, Dunja; Zervou, Sevasti; Faller, Kiterie M. E.; McAndrew, Debra J.; Schneider, Jurgen E.; Neubauer, Stefan; Lygate, Craig A.

    2014-01-01

    Background Multiple studies suggest creatine mediates anti-oxidant activity in addition to its established role in cellular energy metabolism. The functional significance for the heart has yet to be established, but antioxidant activity could contribute to the cardioprotective effect of creatine in ischaemia/reperfusion injury. Objectives To determine whether intracellular creatine levels influence responses to acute reactive oxygen species (ROS) exposure in the intact beating heart. We hypothesised that mice with elevated creatine due to over-expression of the creatine transporter (CrT-OE) would be relatively protected, while mice with creatine-deficiency (GAMT KO) would fare worse. Methods and Results CrT-OE mice were pre-selected for creatine levels 20–100% above wild-type using in vivo 1H–MRS. Hearts were perfused in isovolumic Langendorff mode and cardiac function monitored throughout. After 20 min equilibration, hearts were perfused with either H2O2 0.5 µM (30 min), or the anti-neoplastic drug doxorubicin 15 µM (100 min). Protein carbonylation, creatine kinase isoenzyme activities and phospho-PKCδ expression were quantified in perfused hearts as markers of oxidative damage and apoptotic signalling. Wild-type hearts responded to ROS challenge with a profound decline in contractile function that was ameliorated by co-administration of catalase or dexrazoxane as positive controls. In contrast, the functional deterioration in CrT-OE and GAMT KO hearts was indistinguishable from wild-type controls, as was the extent of oxidative damage and apoptosis. Exogenous creatine supplementation also failed to protect hearts from doxorubicin-induced dysfunction. Conclusions Intracellular creatine levels do not influence the response to acute ROS challenge in the intact beating heart, arguing against creatine exerting (patho-)physiologically relevant anti-oxidant activity. PMID:25272153

  16. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

    1999-10-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  17. Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

    International Nuclear Information System (INIS)

    Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

    1999-01-01

    Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

  18. Hydroxyl radicals' production and ECG parameters during ischemia and reperfusion in rat, guinea pig and rabbit isolated heart.

    Science.gov (United States)

    Paulova, Hana; Stracina, Tibor; Jarkovsky, Jiri; Novakova, Marie; Taborska, Eva

    2013-06-01

    Ischemic and reperfusion injury is a serious condition related to numerous biochemical and electrical abnormalities of the myocardium. It has been repeatedly studied in various animal models. In this study, the production of hydroxyl radicals and electrophysiological parameters were compared in three species. Rat, guinea pig and rabbit isolated hearts were perfused according to Langendorff under strictly identical conditions. The heart rate and arrhythmia were monitored during ischemia and reperfusion periods at defined time intervals; the production of hydroxyl radical was determined by HPLC as 2.5-dihydroxybenzoic acid (2.5-DHBA) formed by salicylic acid hydroxylation. Relationship between arrhythmias and production of 2.5-DHBA was studied. The inter-species differences were observed in timing of arrhythmias onset and their severity, and in the production of 2.5-DHBA in both ischemia and reperfusion. The most considerable changes were observed in rats, where arrhythmias appeared early and with highest severity during ischemia on one side and the regular rhythm was restored early and completely during reperfusion. The corresponding changes in the production of 2.5-DHBA were observed. It can be concluded that rat isolated heart is the most suitable model for evaluation of ischemia/reperfusion injury under given experimental conditions.

  19. Pemanfaatan kulit kodok (bull frog

    Directory of Open Access Journals (Sweden)

    Muchtar Lutfie

    1995-06-01

    Full Text Available The objective of this study was to measure the tensile strength and the elongation of finished leather made from Bull Frog skin, so that the utilization of that leather can be specified. The samples used were twenty pieces of wet salted Bull Frog skin from East Java which have been processed to finished leather using chromosal B. and Irgatan LV as the tanning agents. Laboratory tests shawed that the average tensile strength was 177,675 Kg/Cm2 and the average elongation was 89,9%. Based on those results, it can be concluded that Bull Frog leather was suitable for leather goods such as bag, wallet, etc. so it can be used as substitute for Glace leather.

  20. The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

    Directory of Open Access Journals (Sweden)

    Marcio Mageski

    2015-10-01

    Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

  1. Ventricular filling slows epicardial conduction and increases action potential duration in an optical mapping study of the isolated rabbit heart

    Science.gov (United States)

    Sung, Derrick; Mills, Robert W.; Schettler, Jan; Narayan, Sanjiv M.; Omens, Jeffrey H.; McCulloch, Andrew D.; McCullough, A. D. (Principal Investigator)

    2003-01-01

    INTRODUCTION: Mechanical stimulation can induce electrophysiologic changes in cardiac myocytes, but how mechanoelectric feedback in the intact heart affects action potential propagation remains unclear. METHODS AND RESULTS: Changes in action potential propagation and repolarization with increased left ventricular end-diastolic pressure from 0 to 30 mmHg were investigated using optical mapping in isolated perfused rabbit hearts. With respect to 0 mmHg, epicardial strain at 30 mmHg in the anterior left ventricle averaged 0.040 +/- 0.004 in the muscle fiber direction and 0.032 +/- 0.006 in the cross-fiber direction. An increase in ventricular loading increased average epicardial activation time by 25%+/- 3% (P action potential duration at 20% repolarization (APD20) but did at 80% repolarization (APD80), from 179 +/- 7 msec to 207 +/- 5 msec (P action potential duration by a load-dependent mechanism that may not involve stretch-activated channels.

  2. Effects of Scirpusin B, a polyphenol in passion fruit seeds, on the coronary circulation of the isolated perfused rat heart

    Directory of Open Access Journals (Sweden)

    Yutaka Matsumoto, Nozomi Gotoh, Shoko Sano, Kenkichi Sugiyama, Tatsuhiko Ito, Yohei Abe, Yumi Katano, Akira Ishihata

    2014-07-01

    Full Text Available Objective: Piceatannol, a polyphenol which is contained in passion fruits seed, is a derivative of resveratrol and is known to have antioxidant, anti-inflammatory and vasorelaxing activities. Passion fruits seed also contains a dimer of Piceatannol, Scirpusin B. The aim of this study was to investigate the effect of Scirpusin B on the coronary circulation of the isolated rat heart. Methods: Hearts were isolated from male Fischer 344 rats (5 – 6 months old, and perfused with modified Krebs-Henseleit solution aerated with 95% O2 and 5% CO2 (37 °C at constant pressure (75 cmH2O by Langendorff’s method. Piceatannol or Scirpusin B (10, 30 and 100 μM was injected as a bolus into the aortic cannula and coronary flow (CF was continuously measured by the electromagnetic flow meter. In some experiments, rat hearts were pretreated with L-NAME (an inhibitor of nitric oxide synthase or Diclofenac (an inhibitor of cyclooxygenase to reveal the possible involvement of nitric oxide (NO and vasodilating prostanoids in the effect of Scirpusin B. Results: Scirpusin B increased CF up to 108.2 % of the initial value, while Piceatannol did not increase CF. In addition; Scirpusin B increased CF concentration-dependently. Pretreatment with L-NAME or Diclofenac significantly attenuated the Scirpusin B-induced coronary vasodilatation. Scirpusin B did not change the heart rate either left ventricular pressure. Conclusion: This study shows that Scirpusin B could increase CF via production of NO and vasodilating prostanoids.

  3. Actual management and prognosis of severe isolated tricuspid regurgitation associated with atrial fibrillation without structural heart disease.

    Science.gov (United States)

    Takahashi, Yusuke; Izumi, Chisato; Miyake, Makoto; Imanaka, Miyako; Kuroda, Maiko; Nishimura, Shunsuke; Yoshikawa, Yusuke; Amano, Masashi; Imamura, Sari; Onishi, Naoaki; Tamaki, Yodo; Enomoto, Soichiro; Tamura, Toshihiro; Kondo, Hirokazu; Kaitani, Kazuaki; Nakagawa, Yoshihisa

    2017-09-15

    Patients with atrial fibrillation (AF) without structural heart diseases can show severe tricuspid regurgitation (TR), especially among aged people. The aim of this study was to clarify the actual management, prognosis, and prognostic factors for severe isolated TR associated with AF without structural heart diseases. We retrospectively investigated actual management in 178 consecutive patients with severe isolated TR associated with AF between 1999 and 2011 in our institution. Prognosis and its predictors were also investigated in 115 patients (68 persistent TR and 47 transient TR) who were followed-up for >1year. During the follow-up period (mean: 5.9years), event free rate from death due to right-sided heart failure (RHF) was 97% at 5years. Persistent TR was associated with higher risk of hospitalization due to RHF than transient TR (log-rank P=0.048) and death due to RHF were all seen in patients with persistent TR who experienced hospitalization due to RHF. Among patients with persistent TR, right ventricular outflow tract dimension >35.3mm, right atrial area >40.3cm 2 , and tenting height >2.1mm were associated with higher risk of hospitalization due to RHF (adjusted hazard ratio: 3.32, 3.83, and 2.89, respectively; P=0.003, 0.002, and 0.009, respectively). The prognosis of severe isolated TR associated with AF was good with a focus on cardiac death. However, the incidence of cardiac death increased among patients who experienced hospitalization due to RHF. Larger right ventricular outflow tract dimension, right atrial area and tenting height were predictors of hospitalization due to RHF. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Guinea Worm in a Frog

    Centers for Disease Control (CDC) Podcasts

    2017-03-09

    Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

  5. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  6. Isolation and characterization of a Ca/sup 2 +/ carrier candidate from calf heart inner mitochondrial membrane

    Energy Technology Data Exchange (ETDEWEB)

    Jeng, A.Y.

    1979-01-01

    A protein was isolated from calf heart inner mitochondrial membrane with the aid of an electron paramagnetic resonance assay based on the relative binding properties of Ca/sup 2 +/, Mn/sup 2 +/, and Mg/sup 2 +/ to the protein. Partial delipidation of the protein was performed by using either the organic solvent extraction procedure or the silicic acid column chromatography. Control experiments indicated that the Ca/sup 2 +/ transport properties of the isolated protein were not due to the contaminating phospholipids. A complete delipidation procedure was developd by using Sephadex LH-20 column chromatography. Further characterization of the physical and chemical properties of the delipidated protein showed that delipidated protein becomes more hydrophobic in the presence of Ca/sup 2 +/ and alkaline pH in the organic solvent extraction experiments. Two possible models of calciphorin-mediated Ca/sup 2 +/ transport in mitochondria are proposed. (PCS)

  7. CARE AND FEEDING OF FROGS

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2012-01-01

    'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Blériot', appear consistent with a sinusoid of period ∼4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay , the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t delay exceeds the frog libration period P lib , and if damping from Lindblad torques balances driving from co-orbital torques. If t delay ib , then the libration amplitude damps to zero. In the case of Blériot, the frog resonance model can reproduce the observed libration period P lib ≅ 4 yr. However, our simple feedback prescription suggests that Blériot's t delay ∼ 0.01P lib , which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  8. Agonist of inward rectifier K+ channels enhances the protection of ischemic postconditioning in isolated rat hearts.

    Science.gov (United States)

    Liao, Z; Feng, Z; Long, C

    2014-07-01

    Selective inhibition of inward rectifier K + channels could abolish the protection mediated by ischemic preconditioning, but the roles of these channels in ischemic postconditioning have not been well characterized. Our study aims to evaluate the effect of inward rectifier K + channels on the protection induced by ischemic postconditioning. Langendorff-perfused rat hearts (n=8 per group) were split into four groups: postconditioning hearts (IPO group); ischemic postconditioning with BaCl 2 hearts (PB group); ischemic postconditioning with zacopride hearts (PZ group); and without ischemic postconditioning (CON group). After suffering 30 minutes of global ischemia, groups IPO, PB and PZ went through 10 seconds of ischemic postconditioning with three different perfusates: respectively, Krebs-Henseleit buffer (IPO group); 20 μmol/L BaCl 2 (antagonist of the channel, PB group); 1 μmol/L zacopride (agonist of the channel, PZ group). At the end of reperfusion, the myocardial performance was better preserved in the PZ group than the other three groups. The PB group showed no significant differences from the CON group. Our study has shown that the I K1 channel agonist zacopride is associated with the enhancement of ischemic postconditioning. © The Author(s) 2014.

  9. From frog integument to human skin: dermatological perspectives from frog skin biology

    NARCIS (Netherlands)

    Haslam, I.S.; Roubos, E.W.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

    2014-01-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

  10. Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2012-08-01

    Full Text Available Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13. The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2% for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (P<0.001, 138±48 (P<0.01, 142±37 (P<0.001 and 157±40 (P<0.01, respectively. Number and duration of VT and time spent in reversible VF were also reduced by honey. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2% markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (P<0.001, respectively. Conclusion: Postischemic administration of natural honey in global ischemia showed protective effects against ischemia/reperfusion (I/R injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects.

  11. Metabolism in the isolated rat heart: comparison of 125I-BMIPP with 125I-IPPA

    International Nuclear Information System (INIS)

    Chen Shaoliang; Cheng Aiping; Xu Lanwen; Qiao Weiwei

    2008-01-01

    Objective: The fatty acid metabolism in myocardium is recently one of the most interesting subjects in nuclear cardiology. The purpose of this study was to clarify the metabolic fate of 125 I-labeled 15-(p-iodophenyl)-3-(R, S)-methyl-pentadecanoic acid ( 125 I-BMIPP) and 15-(p-[ 125 I] iodophenyl) pentadecanoic acid ( 125 I-IPPA) by means of isolated rat hearts. Methods: Ten isolated rat hearts were prepared and perfused with 125 I-BMIPP (5 rats) or 125 I-IPPA (5 rats) for 3 h following a basic perfusion of 30 min. After perfusion, the radioactivity in the recirculated buffer was measured. The metabolites in the buffer were then extracted and analyzed using high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Results: At the beginning (5 rain) of 125 I-BMIPP perfusion, the main radioactive peak appeared on HPLC at 37 min, which remained after 3 h perfusion. Several small peaks eluting were found before the parent peak at 30, 26, 21, 16, 12 and 9 min, respectively. At the beginning (5 min) of 125 I-IPPA perfusion, the main peak appeared on HPLC at 33 min, which disappeared after 3 h. Conclusions: 125 I-BMIPP strongly inhibited beta-oxidation, therefore appeared suitable for myocardial metabolic imaging. 125 I-IPPA was metabolized rapidly. (authors)

  12. Vasotocin has the potential to inhibit basolateral Na(+)/K (+)-pump current across isolated skin of tree frog in vitro, via its V(2)-type receptor/cAMP pathway.

    Science.gov (United States)

    Takada, Makoto; Fujimaki, Kayo; Hokari, Shigeru

    2008-11-01

    Adult frog skin transports Na(+) from the apical to the basolateral side across the skin. Antidiuretic hormone (ADH) is involved in the regulation of Na(+) transport in both mammals and amphibians. We investigated the effect of arginine vasotocin (AVT), the ADH of amphibians, on the short-circuit current (SCC) across intact skin and on the basolateral Na(+)/K(+)-pump current across apically nystatin-permeabilized skin of the tree frog, Hyla japonica, in which the V(2)-type ADH receptor is expressed in vitro. In intact skin, 1 pM AVT had no effect on the SCC, but 10 nM AVT was sufficient to stimulate the SCC since 10 nM and 1 microM of AVT increased the SCC 3.2- and 3.4-fold, respectively (P > 0.9). However, in permeabilized skin, AVT (1 microM) decreased the Na(+)/K(+)-pump current to 0.79 times vehicle control. Similarly, 500 microM of 8Br-cAMP increased the SCC 3.2-fold, yet 1 mM of 8Br-cAMP decreased the Na(+)/K(+)-pump current to 0.76 times vehicle control. Arachidonic acid (10(-5) M) tended to decrease the Na(+)/K(+)-pump current. To judge from these in vitro experiments, AVT has the potential to inhibit the basolateral Na(+)/K(+)-pump current via the V(2)-type receptor/cAMP pathway in the skin of the tree frog.

  13. Pharmacological and physiological assessment of serotonin formation and degradation in isolated preparations from mouse and human hearts.

    Science.gov (United States)

    Gergs, Ulrich; Jung, Franziska; Buchwalow, Igor B; Hofmann, Britt; Simm, Andreas; Treede, Hendrik; Neumann, Joachim

    2017-12-01

    Using transgenic (TG) mice that overexpress the human serotonin (5-HT) 4a receptor specifically in cardiomyocytes, we wanted to know whether 5-HT can be formed and degraded in the mammalian heart and whether this can likewise lead to inotropic and chronotropic effects in this TG model. We noted that the 5-HT precursor 5-hydroxy-tryptophan (5-HTP) can exert inotropic and chronotropic effects in cardiac preparations from TG mice but not from wild-type (WT) mice; similar results were found in human atrial preparations as well as in intact TG animals using echocardiography. Moreover, by immunohistochemistry we could detect 5-HT metabolizing enzymes and 5-HT transporters in mouse hearts as well as in human atria. Hence, in the presence of an inhibitor of aromatic l-amino acid decarboxylase, the positive inotropic effects of 5-HTP were absent in TG and isolated human atrial preparations, and, moreover, inhibitors of enzymes involved in 5-HT degradation enhanced the efficacy of 5-HT in TG atria. A releaser of neurotransmitters increased inotropy in the isolated TG atrium, and this effect could be blocked by a 5-HT 4a receptor antagonist. Fluoxetine, an inhibitor of 5-HT uptake, elevated the potency of 5-HT to increase contractility in the TG atrium. In addition, inhibitors of organic cation and monoamine transporters apparently reduced the positive inotropic potency of 5-HT in the TG atrium. Hence, we tentatively conclude that a local production and degradation of 5-HT in the mammalian heart and more specifically in mammalian myocytes probably occurs. Conceivably, this formation of 5-HT and possibly impaired degradation may be clinically relevant in cases of unexplained tachycardia and other arrhythmias. NEW & NOTEWORTHY The present work suggests that inotropically active serotonin (5-HT) can be formed in the mouse and human heart and probably by cardiomyocytes themselves. Moreover, active degradation of 5-HT seems to occur in the mammalian heart. These findings may again

  14. Effect of immobilization stress on gene expression of catecholamine biosynthetic enzymes in heart auricles of socially isolated rats

    Directory of Open Access Journals (Sweden)

    L. Gavrilovic

    2009-12-01

    Full Text Available Chronic stress is associated with the development of cardiovascular diseases. The sympathoneural system plays an important role in the regulation of cardiac function both in health and disease. In the present study, the changes in gene expression of the catecholamine biosynthetic enzymes tyrosine hydroxylase (TH, dopamine-β-hydroxylase (DBH and phenylethanolamine N-methyltransferase (PNMT and protein levels in the right and left heart auricles of naive control and long-term (12 weeks socially isolated rats were investigated by Taqman RT-PCR and Western blot analysis. The response of these animals to additional immobilization stress (2 h was also examined. Long-term social isolation produced a decrease in TH mRNA level in left auricles (about 70% compared to the corresponding control. Expression of the DBH gene was markedly decreased both in the right (about 62% and left (about 81% auricles compared to the corresponding control, group-maintained rats, whereas PNMT mRNA levels remained unchanged. Exposure of group-housed rats to acute immobilization for 2 h led to a significant increase of mRNA levels of TH (about 267%, DBH (about 37% and PNMT (about 60% only in the right auricles. Additional 2-h immobilization of individually housed rats did not affect gene expression of these enzymes in either the right or left auricle. Protein levels of TH, DBH and PNMT in left and right heart auricles were unchanged either in both individually housed and immobilized rats. The unchanged mRNA levels of the enzymes examined after short-term immobilization suggest that the catecholaminergic system of the heart auricles of animals previously exposed to chronic psychosocial stress was adapted to maintain appropriate cardiovascular homeostasis.

  15. Internal pigment cells respond to external UV radiation in frogs.

    Science.gov (United States)

    Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

    2016-05-01

    Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

  16. MCT1 and MCT4 Expression During Myocardial Ischemic-Reperfusion Injury in the Isolated Rat Heart

    Directory of Open Access Journals (Sweden)

    Yi Zhu

    2013-09-01

    Full Text Available Background/Aims: Myocardium ischemia-reperfusion (I/R injury can be caused by imbalances in cellular metabolism. Lactate, transported by monocarboxylate transporters (MCTs, has been implicated as a mechanism in this process. The present study was designed to investigate the expression and functional role of MCTs in rat hearts during ischemia and reperfusion. Methods: Langendorff-perfused rat hearts were subjected to 20 minutes stabilization, 30 minutes of global ischemia and 60 minutes reperfusion. Hearts were collected serially for detecting expression changes in MCT1, MCT4 during myocardial I/R injury and lactate concentration was measured. Post-ischemic left ventricular function and infract size were determined at end-point, followed by the pretreatment of D-lactate, a competitive inhibitor of MCTs. Results: MCT4 was significantly increased following global ischemia and MCT1 expression was increased during the early stages of reperfusion in isolated rat hearts, while the expression of the ancillary protein CD147 was increased during I/R injury. We determined increases in AMPK phosphorylation status, which was significantly elevated following ischemia and early reperfusion. Blocking monocarboxylate transport by competitive inhibition with D-lactate caused decreased left ventricular performance and increased infarct size. Conclusion: Increased MCT4 expression facilitates lactate extrusion during the ischemic period, while increased MCT1 may facilitate lactate transport into and out of cells simultaneously during early reperfusion, with increases in AMPK phosphorylation status during the myocardial I/R period. Lactate transport by MCTs has a profound protective effect during myocardial ischemia reperfusion injury.

  17. [Periodontal microbiota and microorganisms isolated from heart valves in patients undergoing valve replacement surgery in a clinic in Cali, Colombia].

    Science.gov (United States)

    Moreno, Sandra; Parra, Beatriz; Botero, Javier E; Moreno, Freddy; Vásquez, Daniel; Fernández, Hugo; Alba, Sandra; Gallego, Sara; Castillo, Gilberto; Contreras, Adolfo

    2017-12-01

    Periodontitis is an infectious disease that affects the support tissue of the teeth and it is associated with different systemic diseases, including cardiovascular disease. Microbiological studies facilitate the detection of microorganisms from subgingival and cardiovascular samples. To describe the cultivable periodontal microbiota and the presence of microorganisms in heart valves from patients undergoing valve replacement surgery in a clinic in Cali. We analyzed 30 subgingival and valvular tissue samples by means of two-phase culture medium, supplemented blood agar and trypticase soy agar with antibiotics. Conventional PCR was performed on samples of valve tissue. The periodontal pathogens isolated from periodontal pockets were: Fusobacterium nucleatum (50%), Prevotella intermedia/ nigrescens (40%), Campylobacter rectus (40%), Eikenella corrodens (36.7%), Gram negative enteric bacilli (36.7%), Porphyromonas gingivalis (33.3%), and Eubacterium spp. (33.3%). The pathogens isolated from the aortic valve were Propionibacterium acnes (12%), Gram negative enteric bacilli (8%), Bacteroides merdae (4%), and Clostridium bifermentans (4%), and from the mitral valve we isolated P. acnes and Clostridium beijerinckii. Conventional PCR did not return positive results for oral pathogens and bacterial DNA was detected only in two samples. Periodontal microbiota of patients undergoing surgery for heart valve replacement consisted of species of Gram-negative bacteria that have been associated with infections in extraoral tissues. However, there is no evidence of the presence of periodontal pathogens in valve tissue, because even though there were valve and subgingival samples positive for Gram-negative enteric bacilli, it is not possible to maintain they corresponded to the same phylogenetic origin.

  18. Isolated Non-Compaction of the Left Ventricle in a Patient with New-Onset Heart Failure: Morphologic and Functional Evaluation with Cardiac Multidetector Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Heon [Soonchuhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Kim, Seok Yeon [Seoul Medical Center, Seoul (Korea, Republic of); Schoepf, U. Joseph [Medical University of South Carolina, SC (United States)

    2012-03-15

    We describe a case of new-onset heart failure in a patient in whom cardiac CT enabled the non-invasive diagnosis of isolated non-compaction and associated functional abnormalities of the left ventricle with the concomitant evaluation of coronary arteries. This case highlights the utility of cardiac CT for the morphological and functional evaluation of the heart as a single imaging modality.

  19. An automated multi-modal object analysis approach to coronary calcium scoring of adaptive heart isolated MSCT images

    Science.gov (United States)

    Wu, Jing; Ferns, Gordon; Giles, John; Lewis, Emma

    2012-02-01

    Inter- and intra- observer variability is a problem often faced when an expert or observer is tasked with assessing the severity of a disease. This issue is keenly felt in coronary calcium scoring of patients suffering from atherosclerosis where in clinical practice, the observer must identify firstly the presence, followed by the location of candidate calcified plaques found within the coronary arteries that may prevent oxygenated blood flow to the heart muscle. This can be challenging for a human observer as it is difficult to differentiate calcified plaques that are located in the coronary arteries from those found in surrounding anatomy such as the mitral valve or pericardium. The inclusion or exclusion of false positive or true positive calcified plaques respectively will alter the patient calcium score incorrectly, thus leading to the possibility of incorrect treatment prescription. In addition to the benefits to scoring accuracy, the use of fast, low dose multi-slice CT imaging to perform the cardiac scan is capable of acquiring the entire heart within a single breath hold. Thus exposing the patient to lower radiation dose, which for a progressive disease such as atherosclerosis where multiple scans may be required, is beneficial to their health. Presented here is a fully automated method for calcium scoring using both the traditional Agatston method, as well as the Volume scoring method. Elimination of the unwanted regions of the cardiac image slices such as lungs, ribs, and vertebrae is carried out using adaptive heart isolation. Such regions cannot contain calcified plaques but can be of a similar intensity and their removal will aid detection. Removal of both the ascending and descending aortas, as they contain clinical insignificant plaques, is necessary before the final calcium scores are calculated and examined against ground truth scores of three averaged expert observer results. The results presented here are intended to show the requirement and

  20. Influence of fasting on the myocardial metabolsim of [123I] 16-iodohexadecenoic acid (IHA): a study on isolated rat heart

    International Nuclear Information System (INIS)

    Ghezzi, C.; Bontemps, L.; Demaison, L.; Dubois, F.; Comet, M.; Cuchet, P.

    1986-01-01

    IHA has been proposed for the study of myocardial metabolism by external detection. This requires numerical data on the iodinated fatty acid metabolism of the myocardium which can be derived from an analysis of the time activity curve. We developed a mathematical 4-compartment model for this purpose with compartments 0, 1, 2 and 3 representing vascular IHA, intracellular IHA, esterified forms and iodide, respectively. To validate this model it was applied to the study of the effect of fasting on rat myocardial metabolism. Two groups of rats were used, one fed ad lib. and the other fasted for 36 hours. After a bolus injection of IHA into the perfused rat coronaries myocardial time activity curves were recorded for 30 minutes and the activity distribution in the 4 compartments was simulated. Then intracellular activity in perfused rat heart homogenates was determined at different intervals p.i.. Measured and computed values were found to agree well in all compartments. A 36-hour fast was associated with increased uptake and accelerated β-oxidation, while esterification was unchanged. In conclusion, the proposed mathematical model helps to demonstrate even discrete changes of myocardial fatty acid metabolism in the isolated rat heart. Our results, once again, document the excellent suitability of IHA for assessing myocardial metabolism. (Author)

  1. Post ischemic reperfusion and anoxic perfusion in the isolated heart: alteration in distribution of radionuclides and in protein synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Schreiber, S S; Oratz, M; Rothschild, M A [Veterans Administration Hospital, New York (USA)

    1980-12-01

    Reperfusion after ischemia and perfusion with total anoxia were studied in the isolated guinea pig heart model, Deprivation of oxygen in both situations resulted in a marked shift of circulation from the left to the right ventricle, with markedly increased spaces of distribution of sup(99m)Tc radionuclides and albumin in the latter. In view of the complexities of measuring protein synthesis during ischemia, continuous anoxic perfusion was used to evaluate this parameter in anoxic induced arrest. There was a profound fall in protein synthesis associated with this arrest, accompanied by a fall in ATP, creatine phosphate, glycogen, potassium, and a rise in lactate production. The fall in protein synthesis was more marked in the left ventricle. The changes in synthesis were almost completely prevented by initiating cardiac arrest with high K/sup +/ (16 meq/l) at the same time as anoxia; energy metabolism remained near normal, and recovery of contractility was nearly complete. The studies demonstrated the differences in vascular distribution between the ventricles after ischemia or with perfusion anoxia, the possible difference in availability of substrate to the two ventricles under these conditions, as well as the difference in protein synthetic response, and further support the protective effect of potassium induced arrest on the hypoxic heart.

  2. Extraction of long-chain fatty acids in isolated rat heart during acute low-flow ischemia.

    Science.gov (United States)

    Richter, W S; Fischer, S; Ernst, N; Munz, D L

    2001-07-01

    Although beta-oxidation of fatty acids is suppressed rapidly during ischemia, the behavior of fatty acid extraction at different flow rates is incompletely understood. This study assessed the relationship between flow and extraction of (123)I-iodophenylpentadecanoic acid (IPPA) in the isolated heart model, especially at low flow. Isolated hearts from male Wistar rats (n = 15) were subjected to retrograde perfusion with constant flow (Krebs Henseleit solution containing 10 mmol/L glucose). A latex balloon in the left ventricle allowed isovolumetric contractions and ventricular pressure measurements. The extraction of (123)I-IPPA was assessed with the indicator dilution technique and (99m)Tc-albumin as the intravascular reference. The flow was either increased from the control flow (8 mL/min) until 300% or reduced until 10%. (123)I-IPPA extraction was measured three times before and 10 min after flow alteration. The tracer uptake was estimated from the product of net extraction and flow. The mean (123)I-IPPA extraction at the control flow (third measurement) was 51.6% +/- 2.8%. Between flow rates of approximately 25% and 300%, (123)I-IPPA extraction increased exponentially at decreasing flow rates. At flow rates < or =25% of the control flow, (123)I-IPPA extraction was exponentially higher than predicted. (123)I-IPPA uptake and flow changed largely in parallel. During low flow, the rate-pressure product showed the expected decline (perfusion-contraction matching). The extraction of (123)I-IPPA is preserved and slightly increased (relative to flow) during acute low-flow ischemia.

  3. Microfilarial reduction following ProHeart® 6 and ProHeart® SR-12 treatment in dogs experimentally inoculated with a resistant isolate of Dirofilaria immitis.

    Science.gov (United States)

    McTier, Tom L; Pullins, Aleah; Inskeep, Gregory A; Gagnon, Genevieve; Fan, Huihao; Schoell, Adam; Bidgood, Tara; Login, Joyce; Meeus, Patrick

    2017-11-09

    Emerging resistance of heartworms (Dirofilaria immitis) to macrocyclic lactone (ML) preventives is an increasing concern for veterinarians, pet owners and animal health companies that supply heartworm preventives, with recent reports of resistant isolates identified from the Mississippi Delta region of the United States. Products that are effective in eliminating microfilariae (MF) in dogs harboring resistant heartworm infections could be important in reducing the spread of heartworm resistance. The current study was conducted to investigate the potential for ProHeart® 6 (PH 6; Zoetis) and ProHeart® SR-12 (PH 12; Zoetis) to reduce MF in dogs experimentally inoculated with an isolate of D. immitis (ZoeMo-2012) confirmed to be resistant to MLs. Twenty-three dogs with preexisting heartworm infections (via surgical transplantation) were randomly allocated to four groups based on pretreatment (Day -14) MF counts. On Day 0, dogs received a subcutaneous injection of either saline (placebo-treated control, 6 dogs), PH 6 (0.17 mg/kg, 6 dogs), PH 12 (0.5 mg/kg, 5 dogs) or a single oral dose of moxidectin powder in a gelatin capsule (0.25 mg/kg, 6 dogs). All dogs were bled for MF counts (modified Knott's test) on Days 0 (pretreatment), 1, 3, 7, 14, 21, 28, 42, 56, and 84. Dogs in control and PH 6 groups were also bled for MF counts on Days 112, 140, and 168. No adverse events associated with treatment were observed for any dog. Average reductions in MF counts compared with controls for PH 6 were 9.7% on Day 1, increasing to 75.0% on Day 7, and further to 86.5% on Day 28. On Day 42, average MF reduction increased to 90.3%. Reductions increased further over the next several months with reductions of 91.3, 96.8, 96.6, and 98.9% on Days 56, 84, 112, and 140, respectively. On Day 168, the reduction was 99.3% (P < 0.0001). Average reductions in MF counts compared with controls for PH 12 were 20.9% on Day 1, increasing to 78.9% on Day 7, and further to 91.2% on Day 28. On Day 84

  4. Allozyme comparison of three Trypanosoma species (Kinetoplastida: Trypanosomatidae) of toads and frogs by starch-gel electrophoresis.

    Science.gov (United States)

    Martin, D S; Desser, S S; Hong, H

    1992-04-01

    Six metabolic enzymes, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, isocitrate dehydrogenase, malate dehydrogenase, phosphoglucomutase, and purine nucleoside phosphorylase, from clonal isolates of 3 presumptive species of Trypanosoma (T. fallisi, T. ranarum, and T. rotatorium) from 3 anuran hosts (Bufo americanus, Rana clamitans, and Rana catesbeiana) were compared using starch-gel electrophoresis. Although bands were shared among the different zymodemes of isolates of the same host genus, low genetic polymorphism of the enzyme loci was observed with few apparent shared bands between samples isolated from frogs and toads. A distance value calculated between toad and frog trypanosome isolates suggests the likelihood of long-time separation of species. Cluster analysis based on overall similarity distinguished the trypanosomes of toads and frogs as separate taxa, suggesting that host specificity and observed morphological differences are consistent with heritable allozyme differences.

  5. Action of ouabain and an amino-cardenolide on Na+-pump function and contractility of isolated canine heart cells

    International Nuclear Information System (INIS)

    Porterfield, L.M.; Songu-Mize, E.; Chryssanthis, T.; Caldwell, R.W.

    1986-01-01

    Viable, rod-shaped, Ca ++ -tolerant cells were isolated from the cardiac ventricle of adult mongrel dogs, a digitalis-sensitive species. These cells do not contract spontaneously but contractions were driven by electrical field stimulation. Changes in contractile amplitude were assessed by computer-assisted analysis of recorded phase contrast images. Addition of a polar aminocardenolide (AC), ASI-222, produced a dose-related increase in contractility with a concentration producing a 50% maximal response (RC 50 ) of 4 x 10 -8 M. For ouabain (OB) the RC 50 was 7 x 10 -7 M. Cellular Na + -pump (NaP) function was determined as digitalis-sensitive 86 Rb + -uptake. Addition of AC and OB to these cells produced a dose-related decrease in 86 Rb + -uptake; concentrations which produced a 50% inhibition (IC 50 ) of NaP function were of 6 x 10 -8 M and 1.2 x 10 -6 M for AC and OB, respectively. Their data indicates that in isolated dog heart cells AC is both a more potent inotropic agent and an inhibitor of NaP function by 15-20 fold than OB. The RC 50 and IC 50 for these processes correlate for each glycoside

  6. Direct comparison of cardioprotective effects of necroptosis inhibitors against global ischemia-reperfusion in the isolated rat heart

    Directory of Open Access Journals (Sweden)

    Yu. V. Dmitriev

    2017-01-01

    Full Text Available The study was aimed at comparative assessment of cardioprotective properties of various necroptosis inhibitors in the isolated perfused rat heart subjected to global ischemia-reperfusion.Materials and Methods. The study was performed on 38 male Wistar rats weighting 250–300 g. The following necroptosis inhibitors were tested: necrostatin-1 (Nec-1, necrostatin-5 (Nec-5, necrostatin-1s (Nec1s, and necrosulfonamide (NSA. All tested substances were administered intraperitoneally (i.p. 1 hour prior to heart perfusion. Control animals were treated either with the vehicle (dimethyl sulfoxide, DMSO or with 0,9% sodium chloride solution (Controls. The dose of necroptosis inhibitors was calculated on the basis of effective concentration (EC50 data. One hour after i.p. injection, the animals were anesthetized, the hearts were rapidly excised, the aorta was cannulated and retrogradely perfused according to Langendorff. After stabilization, the perfusion was stopped for 35 minutes, which was followed by 2 hours of reperfusion. Prior to stabilization, fluid-filled polyethylene balloon was placed into the left ventricle for left ventricular pressure registration. Coronary flow was measured at baseline and during reperfusion by means of perfusate collection. The volume of necrotic myocardium was expressed as a percentage of triphenyltetrazolium chloride-negative tissue relative to the entire heart volume.Results. The volume of myocardial necrosis and functional heart parameters were not different between Controls and DMSO group. All tested necroptosis inhibitors demonstrated infarct-limiting effect. However, there were no differences between the groups. The volume of necrotic myocardium was (50,5 ± 7,82%, (29,9 ± 3,42%, (27,7 ± 3,42%, (30,6 ± 3,82%, and (34,7 ± 5,82% in DMSO, Nec-1, Nec-5, Nec-1s, and NSA groups, respectively (p < 0,01 vs. DMSO group.Nec-1s and NSA were shown to improve functional recovery of the heart after ischemia. In particular, left

  7. Hemidesmus indicus and Hibiscus rosa-sinensis Affect Ischemia Reperfusion Injury in Isolated Rat Hearts

    Directory of Open Access Journals (Sweden)

    Vinoth Kumar Megraj Khandelwal

    2011-01-01

    Full Text Available Hemidesmus indicus (L. R. Br. (HI and Hibiscus rosa-sinensis L. (HRS are widely used traditional medicine. We investigated cardioprotective effects of these plants applied for 15 min at concentrations of 90, 180, and 360 μg/mL in Langendorff-perfused rat hearts prior to 25-min global ischemia/120-min reperfusion (I/R. Functional recovery (left ventricular developed pressure—LVDP, and rate of development of pressure, reperfusion arrhythmias, and infarct size (TTC staining served as the endpoints. A transient increase in LVDP (32%–75% occurred at all concentrations of HI, while coronary flow (CF was significantly increased after HI 180 and 360. Only a moderate increase in LVDP (21% and 55% and a tendency to increase CF was observed at HRS 180 and 360. HI and HRS at 180 and 360 significantly improved postischemic recovery of LVDP. Both the drugs dose-dependently reduced the numbers of ectopic beats and duration of ventricular tachycardia. The size of infarction was significantly decreased by HI 360, while HRS significantly reduced the infarct size at all concentrations in a dose-dependent manner. Thus, it can be concluded that HI might cause vasodilation, positive inotropic effect, and cardioprotection, while HRS might cause these effects at higher concentrations. However, further study is needed to elucidate the exact mechanism of their actions.

  8. Chemical labeling studies on isolated and vesicular bovine heart mitochondrial cytochrome c oxidase

    International Nuclear Information System (INIS)

    Venzke, K.S.; Reynolds, K.A.; Prochaska, L.J.

    1987-01-01

    Bovine heart cytochrome c oxidase dispersed in Triton X-100, Tween 80, or dodecyl maltoside was reacted with the water-soluble reagents [ 35 S]-diazonium benzene sulfonate (DABS) (10-100 μM) or [ 125 I]-iodo-DABS (34-55 nM) to map the surface topography of the enzyme in different protein aggregation states. Both reagents gave similar labeling profiles of the enzyme under all conditions. Subunits II, III, and VII were extensively labeled by DABS, while subunits I and VI were unreactive with DABS in each detergent. Subunit V exhibited an increase in DABS labeling when the enzyme was reacted in Tween 80 as compared to the enzyme in Triton X-100 or dodecyl maltoside. Also, components b and c showed an increase in DABS reactivity when the enzyme was modified in dodecyl maltoside. In general, the labeling profile of the enzyme in dodecyl maltoside resembled that of the enzyme in Triton X-100, emphasizing that the mechanism of dispersal of the enzyme by both detergents is similar. Cytochrome c oxidase incorporated into phosphatidylglycerol:phosphatidylcholine(1:20)(w:w) phospholipid vesicles (COV) by cholate dialysis was reacted with DABS and subunits II and III were significantly labeled. Approximately 65-70% of the enzyme in COV was oriented with the cytochrome c binding domain facing the extravesicular medium, as determined by comparison of the DABS labeling in subunit IV in detergent-lysed and intact COV

  9. Chemical camouflage--a frog's strategy to co-exist with aggressive ants.

    Directory of Open Access Journals (Sweden)

    Mark-Oliver Rödel

    Full Text Available Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus. The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.

  10. Increase vs. decrease of calcium uptake by isolated heart cells induced by H2O2 vs. HOCl

    International Nuclear Information System (INIS)

    Kaminishi, T.; Matsuoka, T.; Yanagishita, T.; Kako, K.J.

    1989-01-01

    Adult rat heart myocytes were labeled rapidly with exogenous [45Ca2+]. Addition of 2.5 mM H2O2 to the heart cell suspension raised the content of rapidly exchangeable intracellular Ca2+ twofold, whereas addition of 1-30 mM HOCl decreased the Ca2+ content. The H2O2-induced increase in Ca2+ content was dependent on the medium Na+, pH, and temperature but was not significantly affected by addition of verapamil, diltiazem, amiloride, or 3-aminobenzamide. The [3H]ouabain binding to myocytes was suppressed by H2O2, whereas the Ca2+ efflux from myocytes was not influenced. An uncoupler, carbonyl cyanide m-chlorophenylhydrazone, reduced Ca2+ content, implying that the H2O2-induced change in Ca2+ content was not directly related to ATP depletion. On the other hand, the H2O2-induced Ca2+ accumulation in myocytes was prevented by deferoxamine or o-phenanthroline. These results suggest that H2O2 inhibited Na+-K+-ATPase, resulting in an increase in intracellular Na+ concentration and stimulation of sarcolemmal Na+-Ca2+ exchange activity, which caused a transient net Ca2+ influx into myocytes. By contrast, HOCl decreased the Ca2+ content of the rapidly exchangeable pool below control levels and this action of HOCl was antagonized by 1,4-dithiothreitol. HOCl accelerated Ca2+ efflux from myocytes. Ca2+ uptake and Ca2+-ATPase of the isolated sarcoplasmic reticular (SR) fraction were highly sensitive to the action of HOCl. Ca2+ uptake by intracellular sites, studied with myocytes permeabilized with digitonin, was inhibited by both H2O2 and HOCl. Thus these results suggest that HOCl inhibits the SR Ca2+ pump, resulting in the observed acceleration of Ca2+ efflux from and decline in Ca2+ content of myocytes

  11. Glucagon effects on 3H-histamine uptake by the isolated guinea-pig heart during anaphylaxis.

    Science.gov (United States)

    Rosic, Mirko; Parodi, Oberdan; Jakovljevic, Vladimir; Colic, Maja; Zivkovic, Vladimir; Jokovic, Vuk; Pantovic, Suzana

    2014-01-01

    We estimated the influence of acute glucagon applications on (3)H-histamine uptake by the isolated guinea-pig heart, during a single (3)H-histamine passage through the coronary circulation, before and during anaphylaxis, and the influence of glucagon on level of histamine, NO, O2 (-), and H2O2 in the venous effluent during anaphylaxis. Before anaphylaxis, glucagon pretreatment does not change (3)H-histamine Umax and the level of endogenous histamine. At the same time, in the presence of glucagon, (3)H-histamine Unet is increased and backflux is decreased when compared to the corresponding values in the absence of glucagon. During anaphylaxis, in the presence of glucagon, the values of (3)H-histamine Umax and Unet are significantly higher and backflux is significantly lower in the presence of glucagon when compared to the corresponding values in the absence of glucagon. The level of endogenous histamine during anaphylaxis in the presence of glucagon (6.9-7.38 × 10(-8) μM) is significantly lower than the histamine level in the absence of glucagon (10.35-10.45 × 10(-8) μM). Glucagon pretreatment leads to a significant increase in NO release (5.69 nmol/mL) in comparison with the period before glucagon administration (2.49 nmol/mL). Then, in the presence of glucagon, O2 (-) level fails to increase during anaphylaxis. Also, our results show no significant differences in H2O2 levels before, during, and after anaphylaxis in the presence of glucagon, but these values are significantly lower than the corresponding values in the absence of glucagon. In conclusion, our results show that glucagon increases NO release and prevents the increased release of free radicals during anaphylaxis, and decreases histamine level in the venous effluent during cardiac anaphylaxis, which may be a consequence of decreased histamine release and/or intensified histamine capturing by the heart during anaphylaxis.

  12. Padronização de modelo de coração isolado "working heart" com circulação parabiótica Development of isolated swine "working heart model" with parabiotic circulation

    Directory of Open Access Journals (Sweden)

    Lindemberg da Mota Silveira Filho

    2008-03-01

    Full Text Available OBJETIVO: Desenvolver modelo de coração isolado de suíno "working heart" sob suporte por circulação parabiótica e verificar se o mesmo é estável e se possibilitou de forma efetiva a mensuração dos dados propostos. MÉTODOS: O modelo foi padronizado durante preparação para estudo de associação de agente à solução cardioplégica. Foram realizados 18 experimentos com um animal suporte e um animal doador em cada. O coração do animal doador foi perfundido como coração isolado pelo animal suporte em modo de execução de trabalho ("coração ejetante". O coração isolado foi submetido à isquemia regional por pinçamento da artéria interventricular anterior seguido de isquemia global. Durante reperfusão, com o coração ejetante (em modo "working heart", aos 30, 60 e 90 minutos foram medidos parâmetros hemodinâmicos de contratilidade e metabólicos, obtendo-se assim a elastância máxima (Emáx, o trabalho sistólico pré-recrutável (PRSW, rigidez do ventrículo (EDPRV, fluxo coronariano, consumo de oxigênio e dosagens de lactato e glicose. RESULTADOS: Os animais suporte ficaram estáveis durante todo o experimento. O pH, a pressão parcial de oxigênio e o hematócrito foram mantidos estáveis e dentro da faixa fisiológica. O coração isolado foi perfundido de forma adequada durante todo o experimento. Os dados hemodinâmicos e metabólicos propostos puderam ser mensurados adequadamente e sempre com o coração ejetante, em modo de execução de trabalho ("working heart". CONCLUSÃO: O modelo de coração isolado desenvolvido tipo "working heart" se manteve estável durante todo o experimento, sem a administração de drogas cardiotônicas e possibilitou a mensuração de todos os dados propostos de forma efetiva com o coração executando trabalho.OBJECTIVE: To develop an isolated working heart model with parabiotic circulaton in swines and verify its stability and possibility to allow effective measurements of

  13. Intermittent losartan administration triggers cardiac post-conditioning in isolated rat hearts: role of BK2 receptors.

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    Luca Sgarra

    Full Text Available The angiotensin (Ang and bradykinin (BK tissue-system plays a pivotal role in post-conditioning, but the efficacy of angiotensin type 1 receptor (AT1R blockers (ARBs in post-ischemic strategies is still under investigation. We evaluated functional and morphological outcomes, together with activation of cytosolic RISK pathway kinases, in rat hearts subjected to losartan (LOS or irbesartan (IRB post-ischemic administration.Isolated rat hearts underwent 30 min ischemia and 120 min reperfusion. Post-conditioning was obtained by intermittent (10 s/each or continuous drug infusion during the first 3 min of reperfusion. Left ventricular end-diastolic pressure (LVEDP, left ventricular developed pressure (dLVP, coronary flow (CF, and left ventricular infarct mass (IM were measured together with the activation status of RISK kinases Akt, p42/44 MAPK and GSK3β.When compared to hearts subjected to ischemia/reperfusion (iI/R alone, continuous IRB or LOS administration did not significantly reduce total infarct mass (cIRB or cLOS vs. iI/R, p = 0.2. Similarly, intermittent IRB (iIRB was not able to enhance cardioprotection. Conversely, intermittent LOS administration (iLOS significantly ameliorated cardiac recovery (iLOS vs iI/R, p<0.01. Differences between iLOS and iIRB persisted under continuous blockade of AT2R (iLOS+cPD vs. iIRB+cPD, p<0.05. Interestingly, iLOS cardioprotection was lost when BK2R was simultaneously blocked (iLOS+cHOE vs. iI/R, p = 0.6, whereas concurrent administration of iBK and iIRB replicated iLOS effects (iIRB+iBK vs. iLOS, p = 0.7. At the molecular level, iIRB treatment did not significantly activate RISK kinases, whereas both iLOS and iBK treatments were associated with activation of the Akt/GSK3β branch of the RISK pathways (p<0.05 vs. iI/R, for both.Our results suggest that intermittent losartan is effective in mediating post-conditioning cardioprotection, whereas irbesartan is not. The infarct mass reduction by intermittent

  14. Effects of salicylic acid on post-ischaemic ventricular function and purine efflux in isolated mouse hearts.

    Science.gov (United States)

    Farthing, Don; Gehr, Lynne; Karnes, H Thomas; Sica, Domenic; Gehr, Todd; Larus, Terri; Farthing, Christine; Xi, Lei

    2007-01-01

    Acetyl salicylic acid (aspirin) is one of the most widely used drugs in the world. Various plasma concentrations of aspirin and its predominant metabolite, salicylic acid, are required for its antiarthritic (1.5-2.5 mM), anti-inflammatory (0.5-5.0 mM) or antiplatelet (0.18-0.36 mM) actions. A recent study demonstrated the inhibitory effects of both aspirin and salicylic acid on oxidative phosphorylation and ATP synthesis in isolated rat cardiac mitochondria in a dose-dependent manner (0-10 mM concentration range). In this context, the present study was conducted to determine the effects of salicylic acid on inosine efflux (a potential biomarker of acute cardiac ischaemia) as well as cardiac contractile function in the isolated mouse heart following 20 min of zero-flow global ischaemia. Inosine efflux was found at significantly higher concentrations in ischaemic hearts perfused with Krebs buffer fortified with 1.0 mM salicylic acid compared with those without salicylic acid (12575+/-3319 vs. 1437+/-348 ng ml(-1) min(-1), mean+/-SEM, n=6 per group, psalicylic acid potentiates 8.8-fold ATP nucleotide purine catabolism into its metabolites (e.g. inosine, hypoxanthine). Salicylic acid (0.1 or 1.0 mM) did not appreciably inhibit purine nucleoside phosphorylase (the enzyme converts inosine to hypoxanthine) suggesting the augmented inosine efflux was due to the salicylic acid effect on upstream elements of cellular respiration. Whereas post-ischaemic cardiac function was further depressed by 1.0 mM salicylic acid, perfusion with 0.1 mM salicylic acid led to a remarkable functional improvement despite moderately increased inosine efflux (2.7-fold). We conclude that inosine is a sensitive biomarker for detecting cardiac ischaemia and salicylic acid-induced effects on cellular respiration. However, the inosine efflux level appears to be a poor predictor of the individual post-ischaemic cardiac functional recovery in this ex vivo model.

  15. Legionella cardiaca sp. nov., isolated from a case of native valve endocarditis in a human heart

    Science.gov (United States)

    Pearce, Meghan M.; Theodoropoulos, Nicole; Mandel, Mark J.; Brown, Ellen; Reed, Kurt D.

    2012-01-01

    A Gram-negative, rod-shaped bacterium, designated H63T, was isolated from aortic valve tissue of a patient with native valve endocarditis. 16S rRNA gene sequencing revealed that H63T belongs to the genus Legionella, with its closest neighbours being the type strains of Legionella brunensis (98.8 % similarity), L. londiniensis (97.0 %), L. jordanis (96.8 %), L. erythra (96.2 %), L. dresdenensis (96.0 %) and L. rubrilucens, L. feeleii, L. pneumophila and L. birminghamensis (95.7 %). DNA–DNA hybridization studies yielded values of Legionella. H63T was distinguishable from its neighbours based on it being positive for hippurate hydrolysis. H63T was further differentiated by its inability to grow on BCYE agar at 17 °C, its poor growth on low-iron medium and the absence of sliding motility. Also, H63T did not react with antisera generated from type strains of Legionella species. H63T replicated within macrophages. It also grew in mouse lungs, inducing histopathological evidence of pneumonia and dissemination to the spleen. Together, these results confirm that H63T represents a novel, pathogenic Legionella species, for which the name Legionella cardiaca sp. nov. is proposed. The type strain is H63T ( = ATCC BAA-2315T  = DSM 25049T  = JCM 17854T). PMID:22286905

  16. The cardioprotective and inotropic components of the postconditioning effects of GLP-1 and GLP-1(9-36)a in an isolated rat heart

    DEFF Research Database (Denmark)

    Ossum, Alvilde; van Deurs, Ulla; Engstrøm, Thomas

    2009-01-01

    GLP-1 and its metabolite GLP-1(9-36)a have been shown to exert cardiotropic effects, and were demonstrated to be cardioprotective agents in isolated, postischemic rat or mouse hearts. An agent's total effect on myocardial performance in a postconditioning paradigm is a sum of its myocyte-preservi......GLP-1 and its metabolite GLP-1(9-36)a have been shown to exert cardiotropic effects, and were demonstrated to be cardioprotective agents in isolated, postischemic rat or mouse hearts. An agent's total effect on myocardial performance in a postconditioning paradigm is a sum of its myocyte...... protocol, as exemplified by use of GLP-1 and GLP-1(9-36)a following a global ischemia in isolated rat hearts. Peptides were administered during the first 15min of 120min reperfusion. GLP-1 0.3nM reduced infarct size from 23.2+/-2.4% to 14.1+/-2.3% of area-at-risk (n=15, P=0.0223), an effect abolished......, rather than any true inotropic effect. In contrast, GLP-1(9-36)a did not reduce infarct size significantly, but acted as a strong negative inotrope in postischemic hearts, causing a contractility deficit (LVDP 58.8%, P=0.0004; RPP 58.2%, P=0.0007; dP/dt(max)=58.2%, P=0.0012), quantifiable by an analysis...

  17. Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    Roberta Hack Mendes

    2017-07-01

    Full Text Available Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 supplementation on experimental hyperhomocysteinemia (Hhe induced by homocysteine thiolactone (HcyT. Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6. On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6. After 60 days of treatment, homocysteine (Hcy, cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2-like 2 (NRF2 and glutathione S-transferase (GST immunocontent, and superoxide dismutase (SOD, catalase (CAT, and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62% in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51% in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17% in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53% compared to the CB6 group. Ejection fraction (EF was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI (r = 0.71; P = 0.06 and E/A ratio (r = 0.6; P = 0.01, and between EF and GST activity (r = 0.62; P = 0.02. Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters.   Keywords: Homocysteine; oxidative stress; vitamin B6.

  18. Dependence of Ca outflow and depression of frog myocardium contraction on ryodipine concentration.

    Science.gov (United States)

    Narusevicius, E; Gendviliene, V; Macianskiene, R; Hmelj-Dunai, G; Velena, A; Duburs, G

    1988-02-01

    The effect of ryodipine on calcium outflow from tissues, on contraction force, the duration of action potentials and the relaxation phase time-constant in the contraction cycles of myocardial strips was studied using frog heart preparations. It was found that calcium outflow (delta Ca) as a function on ryodipine concentration can be represented as: (formula; see text) A linear correlation exists between Ca2+, contraction blocking and the shortening of the action potential in the presence of various ryodipine concentrations. Ryodipine (10(-5) mol/l) decreased the relaxation time-constant by about 20% as compared to controls. It was concluded that calcium outflow from myocardial tissues in response to ryodipine is due to blockade of calcium entry into the cells and their output through the Na+--Ca2+ exchange system. Frog heart myocardial contractions are essentially under the control of calcium entry through sarcolemmal calcium channels.

  19. The effect of streptomycin on stretch-induced electrophysiological changes of isolated acute myocardial infarcted hearts in rats.

    Science.gov (United States)

    Fu, Lu; Cao, Jun-xian; Xie, Rong-sheng; Li, Jia; Han, Ying; Zhu, Li-qun; Dai, Ying-nan

    2007-08-01

    To explore whether the stretch of ischaemic myocardium could modulate the electrophysiological characteristics, especially repolarization via mechanoelectric feedback (MEF), as well as the effect of streptomycin (SM) on these changes. Methods Thirty-six wistar rats were randomly divided into four groups: control group (n = 9), SM group (n = 9), myocardial infarction (MI) group (n = 9), and MI + SM group (n = 9). After perfused on Langendorff, the isolated hearts were stretched for 5s by a ballon inflation of 0.2mL. After being stretched, the effect of the stretch was observed for 30s, including the 20, 20-70, 70, and 90% monophasic action potential duration (MAPD), i.e. MAPD(20), MAPD(20-70), MAPD(70), and MAPD(90), respectively, premature ventricular beats (PVB), and ventricular tachycardia (VT). Results The stretch caused a decrease in MAPD(20-70) (both P 0.05, except MAPD(20-70) between the control and SM groups, P maintenance of malignant arrhythmias. SM could significantly inhibit the occurrence of arrhythmias, which may correlate with the effect on blocking stretch-activated ion channels.

  20. Electrophysiologic effects of the IK1 inhibitor PA-6 are modulated by extracellular potassium in isolated guinea pig hearts

    DEFF Research Database (Denmark)

    Hoeker, Gregory S; Skarsfeldt, Mark A; Jespersen, Thomas

    2017-01-01

    in Langendorff-perfused guinea pig hearts. PA-6 (200 nm) or vehicle was perfused into ex-vivo guinea pig hearts for 60 min. Hearts were optically mapped with di-4-ANEPPS to quantify CV and APD at 90% repolarization (APD90). Ventricular APD90was significantly prolonged in hearts treated with PA-6 (115 ± 2...... APD90to a lesser degree, but profoundly increased CV Thus, in intact guinea pig hearts, the electrophysiologic effects of the IK1inhibitor, PA-6, are [K+]o-dependent....

  1. Neuromuscular control of prey capture in frogs.

    OpenAIRE

    Nishikawa, K C

    1999-01-01

    While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions. (1) How do frog tongues differ biomechanically? (2) What anatomical and physiological differences are responsible? (3) How is biomechanics related to mechanisms of neuromuscular cont...

  2. Prey specialization and diet of frogs in Borneo

    OpenAIRE

    Ahlm, Kristoffer

    2015-01-01

    Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet. However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization. The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the 156 k...

  3. Influence of β-adrenoceptor stimulation on the metabolism of C 18 unsaturated fatty acids in isolated heart of rat

    International Nuclear Information System (INIS)

    Makdissi, Samar

    1993-02-01

    The influence of stimulating β receptors on the metabolism of 18:1 n-9, 18:2 n-6 and 18:3 n-3 acids in an isolated perfused heart of a rat was studied. Experiments were carried out in two stages. In the first stage, each fatty acid was entered solely in Krebs liquid labelled with C 14 and complexed with albumin. In the second stage, isoproterenol (10 -4 M) was added to the previous mixture in order to stimulate the cardiac β-receptors. It appeared that the heart extracts each of 18:1 and 18:3 in a rate that exceeds the rate of extracting 18:2 and that the oxidation rate of 18:1 was the highest among the three studied acids which were alike in their esterification so they were all entered mainly in the triglycerid group (65-66%) and to less extend in the phospholipids (16-18%). While, the diglycerid and the free fatty acids did only form secondary compounds that would soon convert to the other groups that are more stable the reactions of double bond breakage for the 18:1 acid that converts to triple bond derivatives and 18:3 that converts to tetra, penta and hexa derivatives in the triglycerid were noticed. The 18:3 acid was the least influenced by the stimulation of β. The uptake rate of 18:2 acid was increased slightly while the 18:1 was decreased would indicate a competition between this acid ant the stored one in the cell. Also, the oxidation rate of 18:1 acid as well as the rate of entering it in the triglycerid and the phospholipids increased. In the same way, the oxidation rate of 18:2 acid increased, but its esterification turned in a way that the rate of entering it among the phospholipids increased, while the rate of entering it in the triglycerid decreased. According to what has been mentioned above, it can be said that the 18:1 plays an essential role in the production of direct power besides its role as a component of phospholipids that are deposited in the cellular membranes, while the metabolism of 18:2 acid turns-largely towards the phospholipids

  4. Glucagon Effects on 3H-Histamine Uptake by the Isolated Guinea-Pig Heart during Anaphylaxis

    Directory of Open Access Journals (Sweden)

    Mirko Rosic

    2014-01-01

    Full Text Available We estimated the influence of acute glucagon applications on 3H-histamine uptake by the isolated guinea-pig heart, during a single 3H-histamine passage through the coronary circulation, before and during anaphylaxis, and the influence of glucagon on level of histamine, NO, O2-, and H2O2 in the venous effluent during anaphylaxis. Before anaphylaxis, glucagon pretreatment does not change 3H-histamine Umax and the level of endogenous histamine. At the same time, in the presence of glucagon, 3H-histamine Unet is increased and backflux is decreased when compared to the corresponding values in the absence of glucagon. During anaphylaxis, in the presence of glucagon, the values of 3H-histamine Umax and Unet are significantly higher and backflux is significantly lower in the presence of glucagon when compared to the corresponding values in the absence of glucagon. The level of endogenous histamine during anaphylaxis in the presence of glucagon (6.9–7.38 × 10−8 μM is significantly lower than the histamine level in the absence of glucagon (10.35–10.45 × 10−8 μM. Glucagon pretreatment leads to a significant increase in NO release (5.69 nmol/mL in comparison with the period before glucagon administration (2.49 nmol/mL. Then, in the presence of glucagon, O2- level fails to increase during anaphylaxis. Also, our results show no significant differences in H2O2 levels before, during, and after anaphylaxis in the presence of glucagon, but these values are significantly lower than the corresponding values in the absence of glucagon. In conclusion, our results show that glucagon increases NO release and prevents the increased release of free radicals during anaphylaxis, and decreases histamine level in the venous effluent during cardiac anaphylaxis, which may be a consequence of decreased histamine release and/or intensified histamine capturing by the heart during anaphylaxis.

  5. Diversity within diversity: Parasite species richness in poison frogs assessed by transcriptomics.

    Science.gov (United States)

    Santos, Juan C; Tarvin, Rebecca D; O'Connell, Lauren A; Blackburn, David C; Coloma, Luis A

    2018-08-01

    Symbionts (e.g., endoparasites and commensals) play an integral role in their host's ecology, yet in many cases their diversity is likely underestimated. Although endoparasites are traditionally characterized using morphology, sequences of conserved genes, and shotgun metagenomics, host transcriptomes constitute an underused resource to identify these organisms' diversity. By isolating non-host transcripts from host transcriptomes, individual host tissues can now simultaneously reveal their endoparasite species richness (i.e., number of different taxa) and provide insights into parasite gene expression. These approaches can be used in host taxa whose endoparasites are mostly unknown, such as those of tropical amphibians. Here, we focus on the poison frogs (Dendrobatidae) as hosts, which are a Neotropical clade known for their bright coloration and defensive alkaloids. These toxins are an effective protection against vertebrate predators (e.g., snakes and birds), bacteria, and skin-biting ectoparasites (e.g., mosquitoes); however, little is known about their deterrence against eukaryotic endoparasites. With de novo transcriptomes of dendrobatids, we developed a bioinformatics pipeline for endoparasite identification that uses host annotated RNA-seq data and set of a priori parasite taxonomic terms, which are used to mine for specific endoparasites. We found a large community of helminths and protozoans that were mostly restricted to the digestive tract and a few systemic parasites (e.g., Trypanosoma). Contrary to our expectations, all dendrobatid frogs regardless of the presence of alkaloid defenses have endoparasites, with their highest species richness located in the frog digestive tract. Some of these organisms (e.g., roundworms) might prove to be generalists, as they were not found to be co-diversifying with their frog hosts. We propose that endoparasites may escape poison frogs' chemical defenses by colonizing tissues with fewer alkaloids than the frog's skin

  6. Correlates of virulence in a frog-killing fungal pathogen: evidence from a California amphibian decline.

    Science.gov (United States)

    Piovia-Scott, Jonah; Pope, Karen; Worth, S Joy; Rosenblum, Erica Bree; Poorten, Thomas; Refsnider, Jeanine; Rollins-Smith, Louise A; Reinert, Laura K; Wells, Heather L; Rejmanek, Dan; Lawler, Sharon; Foley, Janet

    2015-07-01

    The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines.

  7. Activation patterns of Purkinje fibers during long-duration ventricular fibrillation in an isolated canine heart model.

    Science.gov (United States)

    Tabereaux, Paul B; Walcott, Greg P; Rogers, Jack M; Kim, Jong; Dosdall, Derek J; Robertson, Peter G; Killingsworth, Cheryl R; Smith, William M; Ideker, Raymond E

    2007-09-04

    The roles of Purkinje fibers (PFs) and focal wave fronts, if any, in the maintenance of ventricular fibrillation (VF) are unknown. If PFs are involved in VF maintenance, it should be possible to map wave fronts propagating from PFs into the working ventricular myocardium during VF. If wave fronts ever arise focally during VF, it should be possible to map them appearing de novo. Six canine hearts were isolated, and the left main coronary artery was cannulated and perfused. The left ventricular cavity was exposed, which allowed direct endocardial mapping of the anterior papillary muscle insertion. Nonperfused VF was induced, and 6 segments of data, each 5 seconds long, were analyzed during 10 minutes of VF. During 36 segments of data that were analyzed, 1018 PF or focal wave fronts of activation were identified. In 534 wave fronts, activation was mapped propagating from working ventricular myocardium to PF. In 142 wave fronts, activation was mapped propagating from PF to working ventricular myocardium. In 342 wave fronts, activation was mapped arising focally. More than 1 of these 3 patterns could occur in the same wave front. PFs are highly active throughout the first 10 minutes of VF. In addition to retrograde propagation from the working ventricular myocardium to PFs, antegrade propagation occurs from PFs to working ventricular myocardium, which suggests PFs are important in VF maintenance. Prior plunge needle recordings in dogs indicate activation propagates from the endocardium toward the epicardium after 1 minute of VF, which suggests that focal sites on the endocardium may represent foci and not breakthrough. If so, in addition to reentry, abnormal automaticity or triggered activity may also occur during VF.

  8. Insulin Preconditioning Elevates p-Akt and Cardiac Contractility after Reperfusion in the Isolated Ischemic Rat Heart

    Directory of Open Access Journals (Sweden)

    Tamaki Sato

    2014-01-01

    Full Text Available Insulin induces cardioprotection partly via an antiapoptotic effect. However, the optimal timing of insulin administration for the best quality cardioprotection remains unclear. We tested the hypothesis that insulin administered prior to ischemia provides better cardioprotection than insulin administration after ischemia. Isolated rat hearts were prepared using Langendorff method and divided into three groups. The Pre-Ins group (Pre-Ins received 0.5 U/L insulin prior to 15 min no-flow ischemia for 20 min followed by 20 min of reperfusion. The Post-Ins group (Post-Ins received 0.5 U/L insulin during the reperfusion period only. The control group (Control was perfused with KH buffer throughout. The maximum of left ventricular derivative of pressure development (dP/dt(max was recorded continuously. Measurements of TNF-α and p-Akt in each time point were assayed by ELISA. After reperfusion, dP/dt(max in Pre-Ins was elevated, compared with Post-Ins at 10 minutes after reperfusion and Control at all-time points. TNF-α levels at 5 minutes after reperfusion in the Pre-Ins were lower than the others. After 5 minutes of reperfusion, p-Akt was elevated in Pre-Ins compared with the other groups. Insulin administration prior to ischemia provides better cardioprotection than insulin administration only at reperfusion. TNF-α suppression is possibly mediated via p-Akt leading to a reduction in contractile myocardial dysfunction.

  9. Role of glycolysis in maintenance of the action potential duration and contractile activity in isolated perfused rat heart.

    Science.gov (United States)

    Opie, L H; Tuschmidt, R; Bricknell, O; Girardier, L

    1980-01-01

    1. Changing substrates from glucose to pyruvate in paced isolated rat hearts, perfused by the Langendorff technique at 65 cm H2O with a Krebs-Henseleit bicarbonate buffer, produced effects which are opposite to those of ouabain treatment: negative inotropy, decreased work efficiency, hyperpolarization, increased maximum rate of rise and amplitude of the action potential, increased conduction velocity. 2. All the effects resulting from perfusion with pyruvate can be reversed by adding ouabain at a concentration of 100 microM. 3. The correlation between various tissue metabolises and change in contractile force (delta F), rate of tension development [maximum + (dF/dt)] and rate of relaxation [maximum -(dF/dt)] was studied by multiple linear regression. No significant correlation was found with either glycogen content and tissue lactate or with cAMP and cGMP. A weak negative correlation was found with ATP and phosphocreatine. The strongest correlation was found 76 to 807 nM/g in passing from glucose- to pyruvate-containing perfusion solution. 4. In vitro tests performed with a solution containing high energy phosphates and magnesium at concentrations equal to their calculated values in the cytosol (pH 7.0) showed that a significant negative correlation exists between citrate concentration (range: 1 and 1500 M) and free calcium concentration in the micromole range. 5. It is concluded that the effects of pyruvate (non glucose substrate) perfusion could be mediated by a decrease in cytosolic-free calcium resulting from an increase in intracellular citrate. The observation that all these effects can be reversed by ouabain is taken as a circumstantial evidence of a common mechanism.

  10. [Biological testing of water with different structural states in rats and frogs].

    Science.gov (United States)

    Farashchuk, N F; Mikhaylova, R I; Telenkova, O G

    2014-01-01

    The effect of water samples with different structural states on some physiological indices of white laboratory rats, 5 groups of 10 animals (5 females and 5 males) and frogs has been studied. The investigation was performed for 1 month. For the determination of the content of liquid crystal associates (LCA) in water samples there was used the dilatometric method, the performance of experimental animals was studied by the swimming test (up to total fatigue). The performed experiment on growing rats with the use of water with varying degrees of structuredness showed that according to the weight gain there were optimal water "Lekor" and tap water, treated with Bioptron (the content of the structured fraction is 5.06 +/- 0.09% and 6.9 +/- 0.23%, respectively). On physical performance the best indices were in animals consumed water treated with the Bioptron lamp. In performance of experiments on frogs it was found that cardiac function in animals under experimental conditions over time weakens spontaneously: heart rate and cardiac output decline. Therefore, the effect of different water samples on the cardiac function was assessed on the intensity of its decrease for 15 minutes. In the experimental study of the effect of water with different content of LCA on heart rate and cardiac output of the frog it was found that the optimum level of structuredness of water is within the range of 5.06 +/- 0.09% (in water "Lekor") - 6.9 +/- 0.23% (tap water treated with Bioptron). All the other water samples, the content of nanocrystals in which was below or above this range, has a pronounced inhibitory effect on the heart performance of the frog.

  11. The Change of a Medically Important Genus: Worldwide Occurrence of Genetically Diverse Novel Brucella Species in Exotic Frogs.

    Science.gov (United States)

    Scholz, Holger C; Mühldorfer, Kristin; Shilton, Cathy; Benedict, Suresh; Whatmore, Adrian M; Blom, Jochen; Eisenberg, Tobias

    2016-01-01

    The genus Brucella comprises various species of both veterinary and human medical importance. All species are genetically highly related to each other, sharing intra-species average nucleotide identities (ANI) of > 99%. Infections occur among various warm-blooded animal species, marine mammals, and humans. Until recently, amphibians had not been recognized as a host for Brucella. In this study, however, we show that novel Brucella species are distributed among exotic frogs worldwide. Comparative recA gene analysis of 36 frog isolates from various continents and different frog species revealed an unexpected high genetic diversity, not observed among classical Brucella species. In phylogenetic reconstructions the isolates consequently formed various clusters and grouped together with atypical more distantly related brucellae, like B. inopinata, strain BO2, and Australian isolates from rodents, some of which were isolated as human pathogens. Of one frog isolate (10RB9215) the genome sequence was determined. Comparative genome analysis of this isolate and the classical Brucella species revealed additional genetic material, absent from classical Brucella species but present in Ochrobactrum, the closest genetic neighbor of Brucella, and in other soil associated genera of the Alphaproteobacteria. The presence of gene clusters encoding for additional metabolic functions, flanked by tRNAs and mobile genetic elements, as well as by bacteriophages is suggestive for a different ecology compared to classical Brucella species. Furthermore it suggests that amphibian isolates may represent a link between free living soil saprophytes and the pathogenic Brucella with a preferred intracellular habitat. We therefore assume that brucellae from frogs have a reservoir in soil and, in contrast to classical brucellae, undergo extensive horizontal gene transfer.

  12. Pharmacological activation of rapid delayed rectifier potassium current suppresses bradycardia-induced triggered activity in the isolated guinea pig heart

    DEFF Research Database (Denmark)

    Hansen, Rie Schultz; Olesen, Søren-Peter; Grunnet, Morten

    2007-01-01

    arrhythmias. We present here data that support that NS3623 affects native I(Kr) and report the effects that activating this potassium current have in the intact guinea pig heart. In Langendorff-perfused hearts, the compound showed a concentration-dependent shortening of action potential duration, which...

  13. THE PROPELLER AND THE FROG

    International Nuclear Information System (INIS)

    Pan, Margaret; Chiang, Eugene

    2010-01-01

    'Propellers' in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the 'frog' resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bleriot in Saturn's A ring, our theory predicts a libration period of ∼4 years, similar to the ∼3.7 year period over which Bleriot's orbital longitude is observed to vary. These librations should be subtracted from the longitude data before any inferences about moonlet migration are made.

  14. Evaluation of Chronic Physical and Psychological Stress Induction on Cardiac Ischemia / Reperfusion Injuries in Isolated Male Rat Heart: The Role of Sympathetic Nervous System

    Directory of Open Access Journals (Sweden)

    Kamran Rakhshan

    2015-10-01

    Full Text Available Exposure to stress leads to physiological changes called “stress response” which are the result ofthe changes in the adrenomedullary hormone system, hypothalamus-pituitary-adrenal (HPA and sympatheticnervous system (SNS activity. In the present study, the effects of chronic physical and psychological stressand also the role of sympathetic system effects in stress on ischemia/reperfusion (I/R injuries have beenstudied in isolated rat heart. Rat heart was isolated and subjected to 30 min regional ischemia and 120 minreperfusion. The daily stress was induced for one week prior to I/R induction. Sympathectomy was donechemically by injection of hydroxyl-dopamine prior to stress induction. There were no significant changes inheart rate and Coronary Flow between groups. Left ventricular developed pressure (LVDP and rate productpressure (RPP in both physical and psychological stress groups decreased significantly compared to those incontrol group (Pgroups. Infarct size significantly increased in both physical and psychological stress groups and control group(Pas compared with stress groups (Ppsychological stress prior to ischemia/reperfusion causes enhancement of myocardial injuries and it seemsthat increased sympathetic activity in response to stress is responsible for these adverse effects of stress onischemic/reperfused heart.

  15. Attenuation of ischemia-reperfusion injury by sevoflurane postconditioning involves protein kinase B and glycogen synthase kinase 3 beta activation in isolated rat hearts.

    Science.gov (United States)

    Fang, Neng-Xin; Yao, Yun-Tai; Shi, Chun-Xia; Li, Li-Huan

    2010-12-01

    Volatile anesthetic ischemic postconditioning reduces infarct size following ischemia/reperfusion. Whether phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3 beta (GSK3β) is causal for cardioprotection by postconditioning is controversial. We therefore investigated the impact of PKB/Akt and GSK3β in isolated perfused rat hearts subjected to 40 min of ischemia followed by 1 h of reperfusion. 2.0% sevoflurane (1.0 minimum alveolar concentration) was administered at the onset of reperfusion in 15 min as postconditioning. Western blot analysis was used to determine phosphorylation of PKB/Akt and its downstream target GSK3β after 1 h of reperfusion. Mitochondrial and cytosolic content of cytochrome C checked by western blot served as a marker for mitochondrial permeability transition pore opening. Sevoflurane postconditioning significantly improved functional cardiac recovery and decreased infarct size in isolated rat hearts. Compared with unprotected hearts, sevoflurane postconditioning-induced phosphorylation of PKB/Akt and GSK3β were significantly increased. Increase of cytochrome C in mitochondria and decrease of it in cytosol is significant when compared with unprotected ones which have reversal effects on cytochrome C. The current study presents evidence that sevoflurane-induced cardioprotection at the onset of reperfusion are partly through activation of PKB/Akt and GSK3β.

  16. Slowing of electrical activity in ventricular fibrillation is not associated with increased defibrillation energies in the isolated rabbit heart

    Directory of Open Access Journals (Sweden)

    Jane eCaldwell

    2011-04-01

    Full Text Available Prolonged out-of-hospital ventricular fibrillation (VF arrests are associated with reduced ECG dominant frequency (DF and diminished defibrillation success. Partial reversal of ischaemia increases ECG DF and improves defibrillation outcome. We have investigated the metabolic components of ischaemia responsible for the decline in ECG DF and defibrillation success.Isolated Langendorff-perfused rabbit hearts were loaded with the voltage-sensitive dye RH237. Using a photodiode array, epicardial membrane potentials were recorded at 252 sites (15x15mm on the anterior surface of the left & right ventricles. Simultaneously, a global ECG was recorded. VF was induced by burst pacing, and after 60s, perfusion was either reduced to 6ml/min or the perfusate composition changed to impose hypoxia (95%N2/5%CO2, pH 6.7 (80%O2/20%CO2, or hyperkalaemia (8mM. Using Fast Fourier Transform, power spectra were created from the optical signals and the global ECG. The optical power spectra were summated to give a global power spectrum (pseudoECG. At 600s the minimum defibrillation voltage (MDV was determined by step-up protocol.During VF, the ECG and pseudoECG DF were reduced by low-flow ischaemia (9.0±1.0Hz, p<0.01, n=5 and raised [K+]o (12.2±1.3 Hz, p<0.05, n=7 compared to control (19.2±1.5 Hz, n=20, but were unaffected by acidic pHo (16.7±1.1 Hz, n=11 and hypoxia (14.0±1.2 Hz, n=10. In contrast, the MDV was raised by acidic pH (156.1±26.4V, p<0.001 and hypoxia (154.1±22.1V, p<0.01 compared to control (65.6±2.3V, but comparable changes were not observed in low-flow ischaemia (61.0±0.5V or raised [K+]o (56±3V. In summary, different metabolites are responsible for the reduction in DF and the increase in defibrillation energy during ischaemic VF.

  17. Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium

    Directory of Open Access Journals (Sweden)

    H. Rodriguez-Angulo

    2013-01-01

    Full Text Available Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol.

  18. Birds and frogs in mathematics and physics

    Energy Technology Data Exchange (ETDEWEB)

    Dyson, Freeman J [Institute for Advanced Study, Princeton, NJ (United States)

    2010-11-15

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

  19. Hematophagous insects as vectors for frog trypanosomes.

    Science.gov (United States)

    Ramos, B; Urdaneta-Morales, S

    1977-12-01

    Experimental infections of three hematophagous arthropods (Rhodnius prolixus, Aedes aegypti, and Culex pipiens) with a trypanosome of the Trypanosoma rotatorium complex found in the frogs Hyla crepitans and Leptodactylus insularum revealed that A. aegypti is a good host for the flagellate; the course of development in the intestinal tract of the mosquito is described from 15 minutes to 168 hours. C. pipiens showed only low intestinal infections and R. prolixus did not permit development of the parasite. It is postulated that, in addition to the transmission of T. rotatorium by leeches, batrachophilic mosquitoes may transmit the parasite to frogs of more terrestrial habits by being ingested by these anurans.

  20. Birds and frogs in mathematics and physics

    International Nuclear Information System (INIS)

    Dyson, Freeman J

    2010-01-01

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

  1. The cardioprotective effect of vanillic acid on hemodynamic parameters, malondialdehyde, and infarct size in ischemia-reperfusion isolated rat heart exposed to PM10

    Directory of Open Access Journals (Sweden)

    Esmat Radmanesh

    2017-07-01

    Full Text Available Objective(s: Particulate matter (PM exposure can promote cardiac ischemia and myocardial damage. The effects of PM10 on hemodynamic parameters, lipid peroxidation, and infarct size induced by ischemia-reperfusion injury and the protective effects of vanillic acid (VA in isolated rat heart were investigated. Materials and Methods: Eighty male Wistar rats (250–300 g were divided into 8 groups (n=10: Control, Sham, VAc, VA, PMa (0.5 mg/kg PM, intratracheal instillation, PMb (2.5 mg/kg PM, intratracheal instillation, PMc (5 mg/kg PM, intratracheal instillation, and PMc + VA (5 mg/kg PM, intratracheal instillation; and 10 mg/kg vanillic acid, gavage for 10 days. PM10 was instilled into the trachea in two stages, within 48 hr. After isolating the hearts and transfer to a Langendorff apparatus, hearts were subjected to 30 min ischemia and 60 min reperfusion. Hemodynamic parameters (±dp/dt, LVSP, LVDP, and RPP, production of lipid peroxidation (MDA, and infarct size were assessed. Results: A significant decrease in ±dp/dt, LVSP, LVDP and RPP occurred in PM groups. A significant increase in MDA and myocardial infarct size occurred in PM groups. A significant increase in LVDP, LVSP, ±dp/dt, RPP and decrease in infarct size, MDA, and myocardial dysfunction was observed in groups that received vanillic acid after ischemia–reperfusion. Conclusion: It was demonstrated that PM10 increases MDA, as well as the percentage of cardiac infarct size, and has negative effects on hemodynamic parameters. This study suggests that vanillic acid may serve as an adjunctive treatment in delaying the progression of ischemic heart disease.

  2. Hydrogen sulfide postconditioning protects isolated rat hearts against ischemia and reperfusion injury mediated by the JAK2/STAT3 survival pathway

    Directory of Open Access Journals (Sweden)

    Heng-Fei Luan

    2012-10-01

    Full Text Available The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g were divided into 6 groups (N = 14 per group: time-matched perfusion (Sham group, ischemia/reperfusion (I/R group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM group, and dimethyl sulfoxide (DMSO; <0.2% group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP, left ventricular end-diastolic pressure (LVEDP, and the maximum rate of increase or decrease of left ventricular pressure (± dp/dt max were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05 and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05. However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.

  3. Electrophysiological effects of Chinese medicine Shen song Yang xin (SSYX) on Chinese miniature swine heart and isolated guinea pig ventricular myocytes.

    Science.gov (United States)

    Feng, Li; Gong, Jing; Jin, Zhen-yi; Li, Ning; Sun, Li-ping; Wu, Yi-ling; Pu, Jie-lin

    2009-07-05

    Shen song Yang xin (SSYX) is a compound of Chinese medicine with the effect of increasing heart rate (HR). This study aimed to evaluate its electrophysiological properties at heart and cellular levels. The Chinese miniature swines were randomly assigned to two groups, administered with SSYX or placebo for 4 weeks (n = 8 per group). Cardiac electrophysiological study (EPS) was performed before and after drug administration. The guinea pig ventricular myocytes were enzymatically isolated and whole cell voltage-clamp technique was used to evaluate the effect of SSYX on cardiac action potential (AP). SSYX treatment accelerated the HR from (141.8 +/- 36.0) beats per minute to (163.0 +/- 38.0) beats per minute (P = 0.013) without changing the other parameters in surface electrocardiogram. After blockage of the autonomic nervous system with metoprolol and atropin, SSYX had no effect on intrinsic HR (IHR), but decreased corrected sinus node recovery time (CSNRT) and sinus atrium conducting time (SACT). Intra cardiac EPS showed that SSYX significantly decreased the A-H and A-V intervals as well as shortened the atrial (A), atrioventricular node (AVN) and ventricular (V) effective refractory period (ERP). In isolated guinea pig ventricular myocytes, the most obvious effect of SSYX on action potential was a shortening of the action potential duration (APD) without change in shape of action potential. The shortening rates of APD(30), APD(50) and APD(90) were 19.5%, 17.8% and 15.3%, respectively. The resting potential (Em) and the interval between the end of APD(30) and APD(90) did not significantly change. The present study demonstrates that SSYX increases the HR and enhances the conducting capacity of the heart in the condition of the intact autonomic nervous system. SSYX homogenously decreases the ERP of the heart and shortens the APD of the myocytes, suggesting its antiarrhythmic effect without proarrhythmia.

  4. Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

    Science.gov (United States)

    Rittman, S.E.; Muths, E.; Green, D.E.

    2003-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

  5. New in vitro model for proarrhythmia safety screening: IKs inhibition potentiates the QTc prolonging effect of IKr inhibitors in isolated guinea pig hearts.

    Science.gov (United States)

    Kui, Péter; Orosz, Szabolcs; Takács, Hedvig; Sarusi, Annamária; Csík, Norbert; Rárosi, Ferenc; Csekő, Csongor; Varró, András; Papp, Julius Gy; Forster, Tamás; Farkas, Attila S; Farkas, András

    2016-01-01

    Preclinical in vivo QT measurement as a proarrhythmia essay is expensive and not reliable enough. The aim of the present study was to develop a sensitive, cost-effective, Langendorff perfused guinea pig heart model for proarrhythmia safety screening. Low concentrations of dofetilide and cisapride (inhibitors of the rapid delayed rectifier potassium current, IKr) were tested alone and co-perfused with HMR-1556 (inhibitor of the slow delayed rectifier potassium current, IKs) in Langendorff perfused guinea pig hearts. The electrocardiographic rate corrected QT (QTc) interval, the Tpeak-Tend interval and the beat-to-beat variability and instability (BVI) of the QT interval were determined in sinus rhythm. Dofetilide and HMR-1556 alone or co-perfused, prolonged the QTc interval by 20±2%, 10±1% and 55±10%, respectively. Similarly, cisapride and HMR-1556 alone or co-perfused, prolonged the QTc interval by 11±3%, 11±4% and 38±6%, respectively. Catecholamine-induced fast heart rate abolished the QTc prolonging effects of the IKr inhibitors, but augmented the QTc prolongation during IKs inhibition. None of the drug perfusions increased significantly the Tpeak-Tend interval and the sinus BVI of the QT interval. IKs inhibition increased the QTc prolonging effect of IKr inhibitors in a super-additive (synergistic) manner, and the QTc interval was superior to other proarrhythmia biomarkers measured in sinus rhythm in isolated guinea pig hearts. The effect of catecholamines on the QTc facilitated differentiation between IKr and IKs inhibitors. Thus, QTc measurement in Langendorff perfused guinea pig hearts with pharmacologically attenuated repolarization reserve and periodic catecholamine perfusion seems to be suitable for preclinical proarrhythmia screening. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  7. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  8. Acute administration of fish oil inhibits triggered activity in isolated myocytes from rabbits and patients with heart failure.

    NARCIS (Netherlands)

    den Ruijter, H.M.; Berecki, G.; Verkerk, A.O.; Bakker, D.; Baartscheer, A.; Schumacher, C.A.; Belterman, C.N.; de Jonge, N.; Fiolet, J.W.; Brouwer, I.A.; Coronel, R.

    2008-01-01

    Background-Fish oil reduces sudden death in patients with prior myocardial infarction. Sudden death in heart failure may be due to triggered activity based on disturbed calcium handling. We hypothesized that superfusion with ω3-polyunsaturated fatty acids (ω3-PUFAs) from fish inhibits triggered

  9. Roselle Polyphenols Exert Potent Negative Inotropic Effects via Modulation of Intracellular Calcium Regulatory Channels in Isolated Rat Heart.

    Science.gov (United States)

    Lim, Yi-Cheng; Budin, Siti Balkis; Othman, Faizah; Latip, Jalifah; Zainalabidin, Satirah

    2017-07-01

    Roselle (Hibiscus sabdariffa Linn.) calyces have demonstrated propitious cardioprotective effects in animal and clinical studies; however, little is known about its action on cardiac mechanical function. This study was undertaken to investigate direct action of roselle polyphenols (RP) on cardiac function in Langendorff-perfused rat hearts. We utilized RP extract which consists of 12 flavonoids and seven phenolic acids (as shown by HPLC profiling) and has a safe concentration range between 125 and 500 μg/ml in this study. Direct perfusion of RP in concentration-dependent manner lowered systolic function of the heart as shown by lowered LVDP and dP/dt max , suggesting a negative inotropic effect. RP also reduced heart rate (negative chronotropic action) while simultaneously increasing maximal velocity of relaxation (positive lusitropic action). Conversely, RP perfusion increased coronary pressure, an indicator for improvement in coronary blood flow. Inotropic responses elicited by pharmacological agonists for L-type Ca 2+ channel [(±)-Bay K 8644], ryanodine receptor (4-chloro-m-cresol), β-adrenergic receptor (isoproterenol) and SERCA blocker (thapsigargin) were all abolished by RP. In conclusion, RP elicits negative inotropic, negative chronotropic and positive lusitropic responses by possibly modulating calcium entry, release and reuptake in the heart. Our findings have shown the potential use of RP as a therapeutic agent to treat conditions like arrhythmia.

  10. Multiplex Ligation-Dependent Probe Amplification Analysis of GATA4 Gene Copy Number Variations in Patients with Isolated Congenital Heart Disease

    Directory of Open Access Journals (Sweden)

    Valentina Guida

    2010-01-01

    Full Text Available GATA4 mutations are found in patients with different isolated congenital heart defects (CHDs, mostly cardiac septal defects and tetralogy of Fallot. In addition, GATA4 is supposed to be the responsible gene for the CHDs in the chromosomal 8p23 deletion syndrome, which is recognized as a malformation syndrome with clinical symptoms of facial anomalies, microcephaly, mental retardation, and congenital heart defects. Thus far, no study has been carried out to investigate the role of GATA4 copy number variations (CNVs in non-syndromic CHDs. To explore the possible occurrence of GATA4 gene CNVs in isolated CHDs, we analyzed by multiplex ligation-dependent probe amplification (MLPA a cohort of 161 non-syndromic patients with cardiac anomalies previously associated with GATA4 gene mutations. The patients were mutation-negative for GATA4, NKX2.5, and FOG2 genes after screening with denaturing high performance liquid chromatography. MLPA analysis revealed that normalized MLPA signals were all found within the normal range values for all exons in all patients, excluding a major contribution of GATA4 gene CNVs in CHD pathogenesis.

  11. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria)

    OpenAIRE

    Strong, Becky; Halsall, Crispin James; Ferenčík, Martin; Jones, Kevin Christopher; Shore, Richard Francis; Martin, Francis Luke

    2016-01-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpol...

  12. Calcium regulation in frog peripheral nerve by the blood-nerve barrier

    International Nuclear Information System (INIS)

    Wadhwani, K.C.

    1986-01-01

    The objectives of this research were: (a) to investigate the characteristics of calcium transport across the perineurium and the endoneurial capillaries, and (b) to gain a better understanding of the extent of calcium homeostasis in the endoneurial space. To study the nature of calcium transport across the perineurium, the flux of radiotracer 45 Ca was measured through the perineurial cylinder, isolated from the frog sciatic nerve, and through the perineurium into the nerve in situ. To study the nature of calcium transport across the endoneurial capillaries, the permeability-surface area product (PA) of 45 Ca was determined as a function of the calcium concentration in the blood. To study calcium homeostasis, the calcium content of the frog sciatic nerve was determined as a function of chronic changes in plasma [Ca

  13. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

    OpenAIRE

    Gossling, J; Loesche, W J; Nace, G W

    1982-01-01

    The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs wer...

  14. Inotropic and chronotropic effects of crude extract and its butanol fraction of dry fruit of aegle marmelos linn. in isolated working rat heart

    International Nuclear Information System (INIS)

    Rahman, A.U.

    2016-01-01

    The fruit of Aegle marmelos Linn. is a most edible part of the tree, ripe, unripe and dry fruit is recommended for wide variety of disorders. Lack of pharmacological evaluation limits the use to nutritional value. Dry and ripe fruit of A. marmelos was investigated as crude extract and its butanol fraction in isolated working male Wistar rat heart. Aortic out flow, coronary effluent, cardiac output, dP/dt(max), dP/dt(min), systolic and diastolic pressure, heart rate, and aortic pressure were measured. Preload and after load was kept constant. These parameters are relevant to cardiac physiology and pathological conditions. All the concentrations of crude extract caused concentration-dependent effects. The crude extract decreased coronary effluent at 100.0 and 300.0 mg/mL, increased the dP/dt(max) at 300.0 mg/mL, systolic pressure and aortic pressure were observed maximum at 100.0 mg/mL. Whereas, aortic out flow, dP/dt(min) diastolic pressure and cardiac output and heart rate remained unaffected. The butanol fraction increased the aortic outflow, dP/dt(max), aortic pressure at 10.0 and 30.0 mg/mL maximally. Whereas, dP/dt(min), diastolic pressure and cardiac output remained unaffected. Coronary effluent at 1.0, 10.0, and 30.0 mg/mL and heart rate at 10.0 and 30.0 mg/mL were decreased maximally. It seems that the bioactive compound got concentrated in butanol fraction according to polarity of the solvent. The crude extract and butanol fraction were found to be positive inotropic whereas, butanol fraction showed negative chronotropic effect as well. (author)

  15. Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: Implications for future monitoring

    Science.gov (United States)

    Chelgren, Nathan D.; Pearl, Christopher A.; Bowerman, Jay; Adams, Michael J.

    2007-01-01

    From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology. Movement rates revealed complementary use of sites seasonally, with one small spring being preferred during winter that was rarely used during the rest of the year. Growth rates were significantly higher in ponds that were not used for breeding, and larger size resulted in significantly higher survival. When variation in survival by size was accounted for there was little variation among ponds in survival. Seasonal estimates of survival were lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. Overwintering survival for both genders was relatively high. Our study supports others in suggesting Oregon spotted frogs are specific in their overwintering habitat requirements, and that predator-free springs may be of particular value. We suggest that any future monitoring include measures of the rate of pond succession. Demographic monitoring should include metrics of both frog reproduction and survival: counts of egg masses at all ponds during spring, and capture-recapture study of survival in mid and late summer when capture rates are highest. Additional study of early life stages would be particularly useful to broaden our understanding of the species’ ecology. Specifically, adding intensive capture and marking effort after larval transformation in fall would enable a full understanding of the annual life cycle. Complete study of the annual life cycle is needed to isolate the life stages and mechanisms through which Oregon spotted frogs are affected by stressors such as nonnative predators. Dilman Meadow, which lacks many hypothesized stressors, is an important reference for

  16. The effect of methyl-lidocaine on the biosynthesis of phospholipids de novo in the isolated hamster heart.

    OpenAIRE

    Tardi, P G; Man, R Y; Choy, P C

    1992-01-01

    Methyl-lidocaine is an amphiphilic agent which has been used as an experimental anti-arrhythmic drug. When hamster hearts were perfused with labelled glycerol, the presence of methyl-lidocaine in the perfusate was found to enhance the labelling in phosphatidylserine, phosphatidylinositol, diacylglycerol and triacylglycerol. However, the labelling of phosphatidylcholine and phosphatidylethanolamine was not significantly changed by methyl-lidocaine treatment. Assays in vitro for the enzymes inv...

  17. The cardioprotective effect of thymoquinone on ischemia-reperfusion injury in isolated rat heart via regulation of apoptosis and autophagy.

    Science.gov (United States)

    Xiao, Junhui; Ke, Zun-Ping; Shi, Yan; Zeng, Qiutang; Cao, Zhe

    2018-06-22

    Thymoquinone (TQ), as the active constituents of black cumin (Nigella sativa) seed oil, has been reported to have potential protective effects on the cardiovascular system. This study aimed to investigate the effects and the underlying mechanisms of TQ on myocardial ischemia-reperfusion (I/R) injury in Langendorff-perfused rat hearts. Wister rat hearts were subjected to I/R and the experimental group were pretreated with TQ prior to I/R. Hemodynamic parameters, myocardial infarct size, cardiac marker enzymes, superoxide dismutase (SOD), malondialdehyde (MDA) content, and cardiomyocyte apoptosis were assayed. Compared with the untreated group, TQ preconditioning significantly improved cardiac function, reduced infarct size, decreased cardiac lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) levels, suppressed enedoxidative stress, and apoptosis. In addition, TQ treatment promoted autophagy, which was partially reversed by chloroquine (CQ), a kind of autophagy blocker. Our study suggests that TQ can protect heart against I/R injury, which is associated with anti-oxidative and anti-apoptotic effects through activation of autophagy. © 2018 Wiley Periodicals, Inc.

  18. A comparative study of contractility of the heart ventricle in some ectothermic vertebrates

    Directory of Open Access Journals (Sweden)

    Sergey Kharin

    2009-07-01

    Full Text Available The purpose of this study was to analyze contractility of the heart ventricle in selected reptilian and amphibian species having the same ventricular excitation pattern. Systolic time intervals and indices of contractility of the heart ventricle were measured in anaesthetized frogs, snakes, and tortoises by use of polycardiography. The electromechanical delay was significantly shorter in tortoises compared with the other two species. The isovolumetric contraction time in frogs was approximately twofold longer than in reptiles. The pre-ejection period was the longest in frogs and the shortest in tortoises, whereas snakes were intermediate. The ejection time was slightly longer in tortoises compared with the other two species. The greatest isovolumetric contraction index and the smallest myocardial tension index corresponded to the frog and tortoise heart ventricle, respectively. The intrasystolic index in tortoises was significantly greater than in frogs, whereas quite similar to that in snakes. The frog ventricle had lower contractility compared with the reptilian one. Although ventricular contractility tended to be lower in snakes compared with tortoises, this difference was not statistically significant. Possible causes for these differences are discussed. We suppose a large variety in ventricular contractility among amphibian and reptilian species having the same ventricular activation pattern. This variety may be conditioned by heart anatomy, intracardiac shunting, lifestyles, and habitats. It can only be hypothesized that on the average, ventricular contractility is higher in reptiles compared with amphibians and in chelonians compared with snakes.

  19. Peptidomic analysis of skin secretions supports separate species status for the tailed frogs, Ascaphus truei and Ascaphus montanus

    Science.gov (United States)

    Conlon, J.M.; Bevier, C.R.; Coquet, L.; Leprince, J.; Jouenne, T.; Vaudry, H.; Hossack, B.R.

    2007-01-01

    The tailed frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue and Wallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the products of orthologous ascaphin genes in electrically-stimulated skin secretions from inland range specimens. Structural characterization of the peptides demonstrated that ascaphins from the inland range contained the following amino acid substitutions compared with orthologs from the coastal range frogs: ascaphin-1 (Ala12 → Glu), ascaphin-3 (Asp4 → Glu), ascaphin-4 (Ala19 → Ser), ascaphin-5 (Lys12 → Thr), and ascaphin-7 (Gly8 → Ser and Ser20 → Asn). Orthologs of ascaphins-2, -6, and -8 were not identified but a paralog of ascaphin-5, identical to ascaphin-5 from coastal range frogs, was found. The data support the claims, derived from analysis of the nucleotide sequences of mitochondrial genes, that the inland populations of the tailed frog should be recognized as a distinct species, the Rocky Mountain tailed frog Ascaphus montanus and that the divergence of the species from A. truei probably occurred in the late Miocene (approximately 10 Mya).

  20. Apomorphine effects on frog locomotor behavior

    OpenAIRE

    Chu, Joanne; Wilczynski, Walter

    2007-01-01

    The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology. DA is well known for its role in facilitating motor behaviors in mammals. We examined whether a similar role for DA exists in amphibians using the Northern Leopard Frog (Rana pipiens). We investigated the effects of the nonspecific DA agonist, apomorp...

  1. Vocal competition in male Xenopus laevis frogs

    OpenAIRE

    Tobias, Martha L.; Corke, Anna; Korsh, Jeremy; Yin, David; Kelley, Darcy B.

    2010-01-01

    Male Xenopus laevis frogs produce underwater advertisement calls that attract gravid females and suppress calling by male competitors. Here we explore whether groups of males establish vocal ranks and whether auditory cues alone suffice for vocal suppression. Tests of male–male pairs within assigned groups reveal linear vocal dominance relations, in which each male has a defined rank. Both the duration over which males interact, as well as the number of competitive opportunities, affect linea...

  2. Cellular mechanisms of nociception in the frog

    Czech Academy of Sciences Publication Activity Database

    Kuffler, D. P.; Lyfenko, Alla; Vyklický st., Ladislav; Vlachová, Viktorie

    2002-01-01

    Roč. 88, č. 4 (2002), s. 1843-1850 ISSN 0022-3077 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Grant - others:NATO(XX) Grant 977062 Institutional research plan: CEZ:AV0Z5011922 Keywords : cellular mechanisms of nociception * frog Subject RIV: FH - Neurology Impact factor: 3.743, year: 2002

  3. Biogeographic patterns of Colombian frogs and toads

    International Nuclear Information System (INIS)

    Lynch, John D.; Ruiz Carranza, Pedro M; Ardila Robayo, Maria Cristina

    1997-01-01

    Using the data provided in Ruiz-Carranza et al. (1996) the distributions of the 540 species of frogs and toads are partitioned among ten ecogeographic units of Colombia defined on the basis of precipitation and elevation. Some lowlands areas (pacific lowlands, Amazonian) exhibit high diversity (85-94 species) but lowlands areas in general are impoverished (30-52 species), especially when contrasted with upland areas. The three Andean cordilleras harbor between 87 and 121 species of frogs and toads, demonstrating that the biodiversity of Colombia resides primarily in its montane components, not in its lowland rain forests. When biological endemicity is separated from political endemicity, five areas of high endemicity remain (the three Andean cordilleras, the Sierra Nevada de Santa Marta, and the pacific lowlands). We endeavor to explain this description by recourse to cladistic analyses of several groups of leptodactylid frogs where we find that the general pattern of diversification is by means of horizontal diversification (allopatric speciation) with a minor contribution from vertical diversification

  4. Antimicrobial Activity of Chlorhexidine, Peracetic acid/ Peroxide hydrogen and Alcohol based compound on Isolated Bacteria in Madani Heart Hospital, Tabriz, Azerbaijan, Iran

    Directory of Open Access Journals (Sweden)

    Reza Ghotaslou

    2012-06-01

    Full Text Available Purpose: The aim of present study was to investigate the effect of chemical agents on the clinical isolates in Madani Heart Hospital, Tabriz, Iran. Methods: The minimum bactericide concentration (MBC of disinfectants including chlorhexidine (Fort, peracetic acid (Micro and an alcohol based compound (Deconex on selected bacteria at various dilutions were determined by the standard suspension technique. Results: MBC of Micro, Fort and Deconex were 2-128 mg/L, 2-64 mg/L and 4 - 32 mg/L, respectively. The Gram negative bacteria were more resistance to disinfectant relation to Gram positive bacteria. Conclusion: The results showed that these agents are able to eradicate the bacteria and they can be used lonely.

  5. Amino acid transamination is crucial for ischaemic cardioprotection in normal and preconditioned isolated rat hearts--focus on L-glutamate

    DEFF Research Database (Denmark)

    Løfgren, Bo; Povlsen, Jonas Agerlund; Rasmussen, Lars Ege

    2010-01-01

    We have found that cardioprotection by l-glutamate mimics protection by classical ischaemic preconditioning (IPC). We investigated whether the effect of IPC involves amino acid transamination and whether IPC modulates myocardial glutamate metabolism. In a glucose-perfused, isolated rat heart model...... subjected to 40 min global no-flow ischaemia and 120 min reperfusion, the effects of IPC (2 cycles of 5 min ischaemia and 5 min reperfusion) and continuous glutamate (20 mm) administration during reperfusion on infarct size and haemodynamic recovery were studied. The effect of inhibiting amino acid...... transamination was evaluated by adding the amino acid transaminase inhibitor amino-oxyacetate (AOA; 0.025 mm) during reperfusion. Changes in coronary effluent, interstitial (microdialysis) and intracellular glutamate ([GLUT](i)) concentrations were measured. Ischaemic preconditioning and postischaemic glutamate...

  6. Antimicrobial Activity of Chlorhexidine, Peracetic acid/ Peroxide hydrogen and Alcohol based compound on Isolated Bacteria in Madani Heart Hospital, Tabriz, Azerbaijan, Iran

    Science.gov (United States)

    Ghotaslou, Reza; Bahrami, Nashmil

    2012-01-01

    Purpose: The aim of present study was to investigate the effect of chemical agents on the clinical isolates in Madani Heart Hospital, Tabriz, Iran. Methods: The minimum bactericide concentration (MBC) of disinfectants including chlorhexidine (Fort), peracetic acid (Micro) and an alcohol based compound (Deconex) on selected bacteria at various dilutions were determined by the standard suspension technique. Results: MBC of Micro, Fort and Deconex were 2-128 mg/L, 2-64 mg/L and 4 - 32 mg/L, respectively. The Gram negative bacteria were more resistance to disinfectant relation to Gram positive bacteria. Conclusion: The results showed that these agents are able to eradicate the bacteria and they can be used lonely. PMID:24312771

  7. Two-dimensional multi-heart cutting centrifugal partition chromatography-liquid chromatography for the preparative isolation of antioxidants from Edelweiss plant.

    Science.gov (United States)

    Marlot, Léa; Batteau, Magali; Escofet, Marie-Claire; Nuccio, Sylvie; Coquoin, Véronique; De Vaumas, René; Faure, Karine

    2017-06-30

    The Edelweiss plant has been recognized as a very valuable source of anti-aging principles due to its composition of antioxidants compounds: leontopodic acid A and 3,5-dicaffeoylquinic acid. In this work, off-line multi-heart cutting CPC-LC separation was set up at industrial scale in order to isolate and produce new high quality reference material of these two antioxidants from Edelweiss. For this purpose, CPC and HPLC methods were developed and optimized at laboratory scale and a comprehensive CPCxHPLC analysis of the crude extract was established. Thereby, the CPC method led to a first separation of the target compounds according to their partition coefficient in the solvent system and the HPLC method was performed on the recovered fractions to lead to a second separation. A 2D CPCxHPLC plot was established in order to know the fractions to select at the industrial scale. Then, the CPC and HPLC methods were transferred at industrial scale and the multi-heart cutting CPC-LC was performed in off-line mode. Using CPC with methyl ter-butyl ether-water 1:1 (v/v) solvent system and LC with Denali C18 column, 2g of crude extract sample were injected and leontopodic acid A and 3,5-dicaffeoylquinic acid were recovered with purity over 97%. The compounds were identified by MS and NMR. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Effects of Gallic Acid and Cyclosporine A on Antioxidant Capacity and Cardiac Markers of Rat Isolated Heart After Ischemia/Reperfusion

    Science.gov (United States)

    Badavi, Mohammad; Sadeghi, Najmeh; Dianat, Mahin; Samarbafzadeh, Alireza

    2014-01-01

    Background: Myocardial infarction is one of the important causes of death during old ages. Gallic acid as an antioxidant or cyclosporine A (CsA) as inhibitor of mitochondrial permeability transition pore (mPTP) alone could prevent these complications to some extent, but their combination effect has not been investigated. Objectives: The aim of this study was to determine the combined effect of gallic acid and CsA on antioxidant capacity of isolated heart tissues during ischemia reperfusion. Materials and Methods: Eighty male Wistar rats were randomly assigned to different groups: sham, control (Ca, received saline, 1 mL/kg); 3 groups were pretreated with gallic acid (G1a: 7.5, G2a: 15, G3a: 30 mg/kg) for 10 days, and the other 3 groups were pretreated with gallic acid and received CsA (0.2 µM) for 10 minutes before induction of ischemia and during the first 10 minutes of reperfusion (G1b, G2b and G3b) and the last group received CsA alone (Cb). After 10 days of pretreatment, the heart was isolated and transferred to the Langendorff apparatus and exposed to 30 minutes ischemia followed by 60 minutes of reperfusion. After that cardiac markers and antioxidant enzymes were assessed in cardiac tissues. Results: Lactate dehydrogenase (LDH), Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activity increased and malondialdehyde (MDA) decreased in animals pretreated with gallic acid significantly. However, pretreatment with gallic acid followed by CsA during reperfusion improved the antioxidant capacity and cardiac marker enzymes and restored the lipid peroxidation more effective than gallic acid or CsA alone. Nevertheless, CsA did not change the cardiac marker enzymes significantly. Conclusions: Gallic acid and CsA combination improved antioxidant capacity and cell membrane integrity more than each one alone. Therefore, it can be a therapeutic approach to reduce the I/R injury. PMID:25068044

  9. Hemodynamic and Mechanical Properties of the Proximal Aorta in Young and Middle-Aged Adults With Isolated Systolic Hypertension: The Dallas Heart Study.

    Science.gov (United States)

    Yano, Yuichiro; Neeland, Ian J; Ayers, Colby; Peshock, Ronald; Berry, Jarett D; Lloyd-Jones, Donald M; Greenland, Philip; Mitchell, Gary F; Vongpatanasin, Wanpen

    2017-07-01

    The aim of this study was to assess characteristic impedance (Z c ) of the proximal aorta in young and middle-aged individuals with isolated systolic hypertension (ISH). Z c is an index of aortic stiffness relative to aortic size. In the Dallas Heart Study, 2001 untreated participants 18 to 64 years of age (mean age: 42.3 years; 44% black race) were divided into the following groups based on office blood pressure (BP) measurements: (1) optimal BP (systolic BP [SBP] hypertension (SBP hypertension (SBP ≥140 mm Hg and DBP ≥90 mm Hg; n=178). Z c , aortic arch pulse wave velocity, and minimum ascending aortic size were quantified using cardiovascular magnetic resonance. In multivariable-adjusted linear models, Z c was highest in the ISH group compared with the optimal BP, isolated diastolic hypertension, or systolic-diastolic hypertension groups (103.2±4.0 versus 68.3±2.1, 75.4±6.0, and 88.9±4.8 dyne*seconds/cm 5 , respectively; all P hypertension, or systolic-diastolic hypertension groups (6.3±0.3 versus 4.3±0.1, 4.4±0.4 and 5.5±0.3 m/s, respectively; all P 0.2). Results were similar in a subgroup of 1551 participants 18 to 49 years of age. In a multiracial population-based sample, we found evidence of a mismatch between proximal aortic stiffness and diameter in young and middle-aged adults with ISH. © 2017 American Heart Association, Inc.

  10. Skin microbiota in frogs from the Brazilian Atlantic Forest: Species, forest type, and potential against pathogens.

    Science.gov (United States)

    Assis, Ananda Brito de; Barreto, Cristine Chaves; Navas, Carlos Arturo

    2017-01-01

    The cutaneous microbiota of amphibians can be defined as a biological component of protection, since it can be composed of bacteria that produce antimicrobial compounds. Several factors influence skin microbial structure and it is possible that environmental variations are among one of these factors, perhaps through physical-chemical variations in the skin. This community, therefore, is likely modified in habitats in which some ecophysiological parameters are altered, as in fragmented forests. Our research goal was to compare the skin bacterial community of four anuran species of the Atlantic Forest of Brazil in landscapes from two different environments: continuous forest and fragmented forest. The guiding hypotheses were: 1) microbial communities of anuran skin vary among sympatric frog species of the Atlantic forest; 2) the degree to which forested areas are intact affects the cutaneous bacterial community of amphibians. If the external environment influences the skin microbiota, and if such influences affect microorganisms capable of inhibiting the colonization of pathogens, we expect consequences for the protection of host individuals. We compared bacterial communities based on richness and density of colony forming units; investigated the antimicrobial potential of isolated strains; and did the taxonomic identification of isolated morphotypes. We collected 188 individual frogs belonging to the species Proceratophrys boiei, Dendropsophus minutus, Aplastodiscus leucopygius and Phyllomedusa distincta, and isolated 221 bacterial morphotypes. Our results demonstrate variation in the skin microbiota of sympatric amphibians, but only one frog species exhibited differences in the bacterial communities between populations from fragmented and continuous forest. Therefore, the variation we observed is probably derived from both intrinsic aspects of the host amphibian species and extrinsic aspects of the environment occupied by the host. Finally, we detected

  11. Cloning of Interleukin-10 from African Clawed Frog (Xenopus tropicalis, with the Finding of IL-19/20 Homologue in the IL-10 Locus

    Directory of Open Access Journals (Sweden)

    Zhitao Qi

    2015-01-01

    Full Text Available Interleukin-10 (IL-10 is a pleiotropic cytokine that plays an important role in immune system. In the present study, the IL-10 gene of African clawed frog (Xenopus tropicalis was first cloned, and its expression pattern and 3D structure were also analyzed. The frog IL-10 mRNA encoded 172 amino acids which possessed several conserved features found in IL-10s from other species, including five-exon/four-intron genomic structure, conserved four cysteine residues, IL-10 family motif, and six α-helices. Real-time PCR showed that frog IL-10 mRNA was ubiquitous expressed in all examined tissues, highly in some immune related tissues including kidney, spleen, and intestine and lowly in heart, stomach, and liver. The frog IL-10 mRNA was upregulated at 24 h after LPS stimulation, indicating that it plays a part in the host immune response to bacterial infection. Another IL, termed as IL-20, was identified from the frog IL-10 locus, which might be the homologue of mammalian IL-19/20 according to the analysis results of the phylogenetic tree and the sequence identities.

  12. Heart Health - Brave Heart

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Brave Heart Past Issues / Winter 2009 Table of Contents For ... you can have a good life after a heart attack." Lifestyle Changes Surviving—and thriving—after such ...

  13. Assessment of frog meat utilisation in Ibadan, Oyo state, Nigeria ...

    African Journals Online (AJOL)

    Frogs are among the most threatened species of wildlife in IUCN red list. Its utilisation in Ibadan, a major depot in western Nigeria was therefore conducted with the aim of assessing the forms and trend of use; and amongst others, reasons for frog meat consumption. Data for the study were collected through questionnaire, ...

  14. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

  15. New material of Beelzebufo, a hyperossified frog (Amphibia: Anura from the late cretaceous of Madagascar.

    Directory of Open Access Journals (Sweden)

    Susan E Evans

    Full Text Available The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates.

  16. Underestimation of species richness in neotropical frogs revealed by mtDNA analyses.

    Directory of Open Access Journals (Sweden)

    Antoine Fouquet

    2007-10-01

    Full Text Available Amphibians are rapidly vanishing. At the same time, it is most likely that the number of amphibian species is highly underestimated. Recent DNA barcoding work has attempted to define a threshold between intra- and inter-specific genetic distances to help identify candidate species. In groups with high extinction rates and poorly known species boundaries, like amphibians, such tools may provide a way to rapidly evaluate species richness.Here we analyse published and new 16S rDNA sequences from 60 frog species of Amazonia-Guianas to obtain a minimum estimate of the number of undescribed species in this region. We combined isolation by distance, phylogenetic analyses, and comparison of molecular distances to evaluate threshold values for the identification of candidate species among these frogs.In most cases, geographically distant populations belong to genetically highly distinct lineages that could be considered as candidate new species. This was not universal among the taxa studied and thus widespread species of Neotropical frogs really do exist, contrary to previous assumptions. Moreover, the many instances of paraphyly and the wide overlap between distributions of inter- and intra-specific distances reinforce the hypothesis that many cryptic species remain to be described. In our data set, pairwise genetic distances below 0.02 are strongly correlated with geographical distances. This correlation remains statistically significant until genetic distance is 0.05, with no such relation thereafter. This suggests that for higher distances allopatric and sympatric cryptic species prevail. Based on our analyses, we propose a more inclusive pairwise genetic distance of 0.03 between taxa to target lineages that could correspond to candidate species.Using this approach, we identify 129 candidate species, two-fold greater than the 60 species included in the current study. This leads to estimates of around 170 to 460 frog taxa unrecognized in Amazonia

  17. Isolation and in vitro culture of trypanosomes from Leptodactylus ocellatus from the Atlantic Forest in a new experimental culture medium.

    Science.gov (United States)

    Lemos, M; Souza, C S F; da Costa, S C Gonçalves; Souto-Padrón, T; D'Agosto, M

    2013-02-01

    The purpose of this study was to verify the in vitro development of Trypanosoma sp. isolated from Leptodactylus ocellatus frogs under a new protocol using a biphasic medium composed of Novy, McNeal, and Nicolle (NNN) blood agar medium as a solid phase and liver infusion, brain heart infusion, and tryptose (LIBHIT) medium as a liquid phase. Blood forms, collected by cardiac puncture or after the maceration of different organs, were inoculated in culture tubes containing the biphasic medium composed by NNN and LIBHIT. Trypanosomes were observed 4 days postinoculation; most bloodstream trypomastigotes had differentiated into epimastigotes and amastigotes by this time. Trypomastigotes were again observed in older cultures (7 days). Parasites were successfully subcultured for 8 mo in this medium and successfully cryopreserved. The present study provides a new protocol medium for the isolation and culture of anuran trypanosomes.

  18. Biochemical and molecular characteristics of Listeria monocytogenes isolates from a prosthetic mitral heart valve-bearing patient´s blood cultures

    Directory of Open Access Journals (Sweden)

    Nilma Cintra Leal

    2013-09-01

    Full Text Available Background: In Brazil, listeriosis is not a notifiable disease; thus, the incidence of Brazilian cases remains unknown. Listeria monocytogenes is not always included in automated systems, and its detection depends on the high skill level of microbiology laboratory professionals. This paper describes the characteristics of L. monocytogenes isolates fortuitously obtained from an endocarditis case in Recife, PE, Brazil. Methods: Six bacterial isolates obtained from six blood cultures from a 28-year-old male bearing a prosthetic mitral heart valve were analyzed by PCR using primers specific of L. monocytogenes to confirm a presumptive identification, determine the serotype and presence of the virulence genes (inlA, inlB, inlC, inlJ, hly, plcA, actA, prfA in an attempt to determine the Listeria genotype by PCR-ribotyping. Results: The samples were identified as L. monocytogenes 4b. All investigated virulence genes were amplified by PCR, and the identity of the amplified segments was confirmed by sequencing. A deletion of 105 base pairs was detected in the actA gene. All of the samples generated the same PCR-ribotype pattern, clustered into a single ribotype, and were considered a single strain. Conclusion: L. monocytogenes infection should be considered in endocarditis differential diagnoses, especially among high-risk groups, due to its high pathogenicity and the environmental ubiquity.

  19. BIOCHEMICAL AND MOLECULAR CHARACTERISTICS OF LISTERIA MONOCYTOGENES ISOLATES FROM A PROSTHETIC MITRAL HEART VALVE-BEARING PATIENT´S BLOOD CULTURES

    Directory of Open Access Journals (Sweden)

    Nilma Cintra Lea

    2013-09-01

    Full Text Available Background: In Brazil, listeriosis is not a notifiable disease; thus, the incidence of Brazilian cases remains unknown. Listeria monocytogenes is not always included in automated systems, and its detection depends on the high skill level of microbiology laboratory professionals. This paper describes the characteristics of L. monocytogenes isolates fortuitously obtained from an endocarditis case in Recife, PE, Brazil. Methods: Six bacterial isolates obtained from six blood cultures from a 28-year-old male bearing a prosthetic mitral heart valve were analyzed by PCR using primers specific of L. monocytogenes to confirm a presumptive identification, determine the serotype and presence of the virulence genes (inlA, inlB, inlC, inlJ, hly, plcA, actA, prfA in an attempt to determine the Listeria genotype by PCR-ribotyping. Results: The samples were identified as L. monocytogenes 4b. All investigated virulence genes were amplified by PCR, and the identity of the amplified segments was confirmed by sequencing. A deletion of 105 base pairs was detected in the actA gene. All of the samples generated the same PCR-ribotype pattern, clustered into a single ribotype, and were considered a single strain. Conclusion: L. monocytogenes infection should be considered in endocarditis differential diagnoses, especially among high-risk groups, due to its high pathogenicity and the environmental ubiquity.

  20. PHENOMENON OF DEMIKHOV. "TRANSPLANTATION OF VITAL ORGANS IN EXPERIMENT" (1960. HOMOPLASTIC ORGAN TRANSPLANTATION: OF AN ISOLATED HEART, ISOLATED LUNG, KIDNEY, HEAD, HALF OF THE TRUNK, AND THE WHOLE TRUNK

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    S. P. Glyantsev

    2017-01-01

    Full Text Available The  article  (the third one of five presents the analysis of the final part  of the third chapter on homoplastic organ transplantation from V.P.  Demikhov's monograph "Transplantation of  vital  organs  in  experiment"  (MedGIz Publ., Moscow,  1960. The article covers the data presented by V.P. Demikhov on his creating the following animal models:  of the isolated  heart  and lung,  kidneys, head, half of the trunk, and the whole  trunk. The isolated  heart  models where  the heart  was positioned in place of the biological one were not successful. The longest  period  of the dog-recipient survival was  15 hours. The  dogs with transplanted lobes of  the  lung  survived up  to 6 days  (there  are no evidence of  a whole lung  transplant in the book; animal-recipients of kidneys survived up to 19 days.  V.P. Demikhov considered that  the graft deaths might be caused  by the biological  tissue  incompatibility between  the donor  and  recipient, and  he stressed the  need  for  its suppression and  the  importance of  choosing the  donor  and  recipient compatible by their  blood group for  successful homoplastic transplantation. By  transplanting the puppies' heads  onto  the cervical  vessels  of  the dogs, starting the experiments from 1954, V.P. Demikhov attempted to prove the role of the central nervous system in the organ engraftment, which was one of the targets  in those experiments. The integration of two bodies, combining their vascular systems, and mixing the blood had two goals: to create the conditions for overcoming the transplantation immunity and to make an animal model  of organ transplant in combination with retaining the organ neurohumoral links. The model of the cross circulation also allowed the formulation and implementation of the organ bank concept in the experiment.

  1. Efficacy of ivermectin as an anthelmintic in leopard frogs.

    Science.gov (United States)

    Letcher, J; Glade, M

    1992-02-15

    Ivermectin administered cutaneously at dosages of 2 mg/kg of body weight eliminated nematode infections in leopard frogs. Three clinical trials were conducted. In the first trial, 5 groups of 11 frogs were given ivermectin IM at dosages of 0, 0.2, 0.4, 2, or 20 mg/kg. All frogs given ivermectin IM at dosages of 2.0 mg/kg or greater died. In trial 2, 44 frogs, allotted to 5 groups, were given ivermectin cutaneously at 0, 0.2, 2, or 20 mg/kg. Cutaneously administered ivermectin was not toxic at dosages up to 20 mg/kg. In trial 3, nematode infections were eliminated in all 10 frogs treated cutaneously with ivermectin at 2.0 mg/kg.

  2. Adaptive plasticity of skeletal muscle energetics in hibernating frogs: mitochondrial proton leak during metabolic depression.

    Science.gov (United States)

    Boutilier, Robert G; St-Pierre, Julie

    2002-08-01

    The common frog (Rana temporaria) spends the coldest months of each year overwintering in ice-covered ponds where temperatures can vary from 0.5 to 4.0 degrees C. Over the course of a winter season, the animals enter progressively into a state of metabolic depression that relies almost exclusively on aerobic production of ATP. However, if aerobic metabolism is threatened, for example by increasingly hypoxic conditions, decreases in the animal's metabolic rate can reach upwards of 75% compared with the 50% decrease seen during normoxia. Under these conditions, the major proportion of the overall reduction in whole-animal metabolic rate can be accounted for by metabolic suppression of the skeletal muscle (which makes up approximately 40% of body mass). Little is known about the properties of mitochondria during prolonged periods of metabolic depression, so we have examined several aspects of mitochondrial metabolism in the skeletal muscle of frogs over periods of hibernation of up to 4 months. Mitochondria isolated from the skeletal muscle of frogs hibernating in hypoxic water show a considerable reorganisation of function compared with those isolated from normoxic submerged animals at the same temperature (3 degrees C). Both the active (state 3) and resting (state 4) respiration rates of mitochondria decrease during hypoxic, but not normoxic, hibernation. In addition, the affinity of mitochondria for oxygen increases during periods of acute hypoxic stress during normoxic hibernation as well as during long-term hibernation in hypoxic water. The decrease in mitochondrial state 4 respiration rates during hypoxic hibernation evidently occurs through a reduction in electron-transport chain activity, not through a lowered proton conductance of the mitochondrial inner membrane. The reduced aerobic capacity of frog skeletal muscle during hypoxic hibernation is accompanied by lowered activities of key enzymes of mitochondrial metabolism caused by changes in the intrinsic

  3. Evaluation of the efficacy of ProHeart® 6 (moxidectin against a resistant isolate of Dirofilaria immitis (JYD-34 in dogs

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    Dwight D. Bowman

    2017-11-01

    Full Text Available Abstract Background In a previous study, it was demonstrated that ProHeart® 6 (PH6 (moxidectin, Zoetis provided only about 20% efficacy in a small six-dog study against a macrocyclic lactone –resistant Dirofilaria immitis isolate (Jd2009–2 when dogs were inoculated with infective third-stage larvae (L3 at the end of the dosing period (ie, 180 days post treatment. The objective of the current study was to determine the prophylactic efficacy of a moxidectin sustained-release formulation (PH6 against a confirmed macrocyclic lactone–resistant isolate of D. immitis (JYD-34 in dogs when administered by subcutaneous injection at the labeled dose of 0.17 mg/kg 2 days before L3 inoculation. This was intended to model the scenario where dogs become infected with resistant heartworms at the end of the PH6 treatment period (ie, 6 months post treatment when dogs would routinely be given another injection under normal field use. Methods Twelve purpose-bred Beagle dogs (six males and six females were selected and randomly allocated to two groups, untreated controls and PH6-treated dogs in groups of six each. The dogs were ≥8 months old at the start of the study, and using blood samples collected on Day −7 were shown to be negative for adult heartworm antigen and microfilariae. On Day 0, the dogs in the untreated control group were administered saline subcutaneously by injection, and the dogs in the treated group were administered PH6 according to label instructions. On Day 2, each dog was inoculated in the inguinal area with 50 L3 of D. immitis. The dogs were necropsied on Day 150 (148 days post infection, and the worms were collected and counted. Results All of the six control dogs were infected and harbored a range of 21 to 37 worms (geometric mean, 25.4; 10.9 males and 13.9 females. Only one of the six PH6 dogs was found to be infected, harboring a single male worm. Efficacy was 99.5% (geometric mean. Conclusion ProHeart® 6 was highly

  4. Evaluation of the efficacy of ProHeart® 6 (moxidectin) against a resistant isolate of Dirofilaria immitis (JYD-34) in dogs.

    Science.gov (United States)

    Bowman, Dwight D; McTier, Tom L; Adams, Eric L; Mahabir, Sean P; Login, Joyce A; Bidgood, Tara; Woods, Debra J

    2017-11-09

    In a previous study, it was demonstrated that ProHeart ® 6 (PH6) (moxidectin, Zoetis) provided only about 20% efficacy in a small six-dog study against a macrocyclic lactone -resistant Dirofilaria immitis isolate (Jd2009-2) when dogs were inoculated with infective third-stage larvae (L3) at the end of the dosing period (ie, 180 days post treatment). The objective of the current study was to determine the prophylactic efficacy of a moxidectin sustained-release formulation (PH6) against a confirmed macrocyclic lactone-resistant isolate of D. immitis (JYD-34) in dogs when administered by subcutaneous injection at the labeled dose of 0.17 mg/kg 2 days before L3 inoculation. This was intended to model the scenario where dogs become infected with resistant heartworms at the end of the PH6 treatment period (ie, 6 months post treatment) when dogs would routinely be given another injection under normal field use. Twelve purpose-bred Beagle dogs (six males and six females) were selected and randomly allocated to two groups, untreated controls and PH6-treated dogs in groups of six each. The dogs were ≥8 months old at the start of the study, and using blood samples collected on Day -7 were shown to be negative for adult heartworm antigen and microfilariae. On Day 0, the dogs in the untreated control group were administered saline subcutaneously by injection, and the dogs in the treated group were administered PH6 according to label instructions. On Day 2, each dog was inoculated in the inguinal area with 50 L3 of D. immitis. The dogs were necropsied on Day 150 (148 days post infection), and the worms were collected and counted. All of the six control dogs were infected and harbored a range of 21 to 37 worms (geometric mean, 25.4; 10.9 males and 13.9 females). Only one of the six PH6 dogs was found to be infected, harboring a single male worm. Efficacy was 99.5% (geometric mean). ProHeart ® 6 was highly effective in preventing the development of heartworms in dogs

  5. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  6. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    OpenAIRE

    Edward C. Netherlands; Courtney A. Cook; Donnavan J.D. Kruger; Louis H. du Preez; Nico J. Smit

    2015-01-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracell...

  7. Effects of the new imidazopyridine CL 86-02-01 on isolated papillary muscle of guinea-pig hearts.

    Science.gov (United States)

    Studenik, C; Lemmens-Gruber, R; Heistracher, P

    1998-06-01

    Inotropic activity and the effect of CL 86-02-01 (2-(3-methoxy-5-methylsulfinyl-2-thienyl)-1H-imidazo[4,5-c]pyridine hydrochloride, CAS 109 792-24-7) on membrane resting and action potentials were studied in isolated guinea-pig papillary muscles. Membrane resting potential and action potential parameters were not significantly changed, while CL 86-02-01 exerted a concentration-dependent inotropic effect by increasing the maximum rate of force development and maximum rate of force relaxation. Time to peak force, relaxation time and total contraction time were reduced. These effects are similar to those of beta-adrenergic drugs and phosphodiesterase inhibitors, but markedly differ from those described for other positive inotropic agents like cardiac glycosides, calcium agonists, alpha-adrenergic drugs or increased extracellular calcium concentration.

  8. LOOKING INTO THE HEARTS OF BOK GLOBULES: MILLIMETER AND SUBMILLIMETER CONTINUUM IMAGES OF ISOLATED STAR-FORMING CORES

    International Nuclear Information System (INIS)

    Launhardt, R.; Henning, Th.; Khanzadyan, T.; Schmalzl, M.; Wolf, S.; Nutter, D.; Ward-Thompson, D.; Bourke, T. L.; Zylka, R.

    2010-01-01

    We present the results of a comprehensive infrared, submillimeter, and millimeter continuum emission study of isolated low-mass star-forming cores in 32 Bok globules, with the aim to investigate the process of star formation in these regions. The submillimeter and millimeter dust continuum emission maps together with the spectral energy distributions are used to model and derive the physical properties of the star-forming cores, such as luminosities, sizes, masses, densities, etc. Comparisons with ground-based near-infrared and space-based mid- and far-infrared images from Spitzer are used to reveal the stellar content of the Bok globules, association of embedded young stellar objects (YSOs) with the submillimeter dust cores, and the evolutionary stages of the individual sources. Submillimeter dust continuum emission was detected in 26 out of the 32 globule cores observed. For 18 globules with detected (sub)millimeter cores, we derive evolutionary stages and physical parameters of the embedded sources. We identify nine starless cores, most of which are presumably prestellar, nine Class 0 protostars, and twelve Class I YSOs. Specific source properties like bolometric temperature, core size, and central densities are discussed as a function of evolutionary stage. We find that at least two thirds (16 out of 24) of the star-forming globules studied here show evidence of forming multiple stars on scales between 1000 and 50,000 AU. However, we also find that most of these small prototstar and star groups are comprised of sources with different evolutionary stages, suggesting a picture of slow and sequential star formation in isolated globules.

  9. Pathogenicity of frog virus 3-like virus in red-eared slider turtles (Trachemys scripta elegans) at two environmental temperatures.

    Science.gov (United States)

    Allender, M C; Mitchell, M A; Torres, T; Sekowska, J; Driskell, E A

    2013-01-01

    Ranaviral disease has affected several species of reptiles, but disease progression and mortality in relation to environmental temperature has yet to be determined. In this study, two separate trials challenged adult female red-eared slider turtles (Trachemys scripta elegans) with a ranavirus (frog virus 3-like virus; FV3) isolate at environmental temperatures of 22 °C (n = 4) and 28 °C (n = 4). The mortality rates in the turtles in the 22 °C and 28 °C trials were 100% and 50%, respectively. Median survival time for turtles exposed to FV3 at 22 °C was 24 days, while it was 30 days in the group kept at 28 °C. Consistent microscopical lesions were observed only in the group inoculated at 22 °C and included fibrinoid necrosis of vessels in the spleen, vascular and sinusoidal thrombi in the liver, necrotizing myositis and a mild heterophilic interstitial pneumonia. Quantitative polymerase chain reaction, targeting a conserved portion of the major capsid protein, was able to detect virus copies in whole blood, oral and cloacal swabs, tongue, skeletal muscle, lung, heart, liver, spleen, ovary and kidney. Viral copy number in ante-mortem clinical samples was non-significantly highest in whole blood, while kidney had the highest viral copy number in post-mortem samples. All samples had higher virus copy number in turtles exposed to FV3 at 22 °C compared with 28 °C. This study determined that environmental temperature affects the survival and disease progression in ranavirus-infected red-eared slider turtles, which will aid in managing animals in a clinical or free-ranging setting. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Peatlands and green frogs: A relationship regulated by acidity?

    Science.gov (United States)

    Mazerolle, M.J.

    2005-01-01

    The effects of site acidification on amphibian populations have been thoroughly addressed in the last decades. However, amphibians in naturally acidic environments, such as peatlands facing pressure from the peat mining industry, have received little attention. Through two field studies and an experiment, I assessed the use of bog habitats by the green frog (Rana clamitans melanota), a species sensitive to various forestry and peat mining disturbances. First, I compared the occurrence and breeding patterns of frogs in bog and upland ponds. I then evaluated frog movements between forest and bog habitats to determine whether they corresponded to breeding or postbreeding movements. Finally, I investigated, through a field experiment, the value of bogs as rehydrating areas for amphibians by offering living Sphagnum moss and two media associated with uplands (i.e., water with pH ca 6.5 and water-saturated soil) to acutely dehydrated frogs. Green frog reproduction at bog ponds was a rare event, and no net movements occurred between forest and bog habitats. However, acutely dehydrated frogs did not avoid Sphagnum. Results show that although green frogs rarely breed in bogs and do not move en masse between forest and bog habitats, they do not avoid bog substrates for rehydrating, despite their acidity. Thus, bogs offer viable summering habitat to amphibians, which highlights the value of these threatened environments in terrestrial amphibian ecology.

  11. Ex situ diet influences the bacterial community associated with the skin of red-eyed tree frogs (Agalychnis callidryas.

    Directory of Open Access Journals (Sweden)

    Rachael E Antwis

    Full Text Available Amphibians support symbiotic bacterial communities on their skin that protect against a range of infectious pathogens, including the amphibian chytrid fungus. The conditions under which amphibians are maintained in captivity (e.g. diet, substrate, enrichment in ex situ conservation programmes may affect the composition of the bacterial community. In addition, ex situ amphibian populations may support different bacterial communities in comparison to in situ populations of the same species. This could have implications for the suitability of populations intended for reintroduction, as well as the success of probiotic bacterial inoculations intended to provide amphibians with a bacterial community that resists invasion by the chytrid fungus. We aimed to investigate the effect of a carotenoid-enriched diet on the culturable bacterial community associated with captive red-eyed tree frogs (Agalychnis callidryas and make comparisons to bacteria isolated from a wild population from the Chiquibul Rainforest in Belize. We successfully showed carotenoid availability influences the overall community composition, species richness and abundance of the bacterial community associated with the skin of captive frogs, with A. callidryas fed a carotenoid-enriched diet supporting a greater species richness and abundance of bacteria than those fed a carotenoid-free diet. Our results suggest that availability of carotenoids in the diet of captive frogs is likely to be beneficial for the bacterial community associated with the skin. We also found wild A. callidryas hosted more than double the number of different bacterial species than captive frogs with very little commonality between species. This suggests frogs in captivity may support a reduced and diverged bacterial community in comparison to wild populations of the same species, which could have particular relevance for ex situ conservation projects.

  12. Pomegranate Extract Enhances Endothelium-Dependent Coronary Relaxation in Isolated Perfused Hearts from Spontaneously Hypertensive Ovariectomized Rats

    Science.gov (United States)

    Delgado, Nathalie T. B.; Rouver, Wender do N.; Freitas-Lima, Leandro C.; de Paula, Tiago D.-C.; Duarte, Andressa; Silva, Josiane F.; Lemos, Virgínia S.; Santos, Alexandre M. C.; Mauad, Helder; Santos, Roger L.; Moysés, Margareth R.

    2017-01-01

    Decline in estrogen levels promotes endothelial dysfunction and, consequently, the most prevalent cardiovascular diseases in menopausal women. The use of natural therapies such as pomegranate can change these results. Pomegranate [Punica granatum L. (Punicaceae)] is widely used as a phytotherapeutic agent worldwide, including in Brazil. We hypothesized that treatment with pomegranate hydroalcoholic extract (PHE) would improve coronary vascular reactivity and cardiovascular parameters. At the beginning of treatment, spontaneously hypertensive female rats were divided into Sham and ovariectomized (OVX) groups, which received pomegranate extract (PHE) (250 mg/kg) or filtered water (V) for 30 days by gavage. Systolic blood pressure was measured by tail plethysmography. After euthanasia, the heart was removed and coronary vascular reactivity was assessed by Langendorff retrograde perfusion technique. A dose-response curve for bradykinin was performed, followed by L-NAME inhibition. The protein expression of p-eNOS Ser1177, p-eNOS Thr495, total eNOS, p-AKT Ser473, total AKT, SOD-2, and catalase was quantified by Western blotting. The detection of coronary superoxide was performed using the protocol of dihydroethidium (DHE) staining Plasma nitrite measurement was analyzed by Griess method. Systolic blood pressure increased in both Sham-V and OVX-V groups, whereas it was reduced after treatment in Sham-PHE and OVX-PHE groups. The baseline coronary perfusion pressure was reduced in the Sham-PHE group. The relaxation was significantly higher in the treated group, and L-NAME attenuated the relaxation in all groups. The treatment has not changed p-eNOS (Ser1177), total eNOS, p-AKT (Ser473) and total AKT in any groups. However, in Sham and OVX group the treatment reduced the p-eNOS (Thr495) and SOD-2. The ovariectomy promoted an increasing in the superoxide anion levels and the treatment was able to prevent this elevation and reducing oxidative stress. Moreover, the treatment

  13. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  14. Heart murmurs

    Science.gov (United States)

    Chest sounds - murmurs; Heart sounds - abnormal; Murmur - innocent; Innocent murmur; Systolic heart murmur; Diastolic heart murmur ... The heart has 4 chambers: Two upper chambers (atria) Two lower chambers (ventricles) The heart has valves that close ...

  15. Enzyme characterisation, isolation and cDNA cloning of polyphenol oxidase in the hearts of palm of three commercially important species.

    Science.gov (United States)

    Shimizu, Milton Massao; Melo, Geraldo Aclécio; Brombini Dos Santos, Adriana; Bottcher, Alexandra; Cesarino, Igor; Araújo, Pedro; Magalhães Silva Moura, Jullyana Cristina; Mazzafera, Paulo

    2011-09-01

    Heart of palm (palmito) is the edible part of the apical meristem of palms and is considered a gourmet vegetable. Palmitos from the palms Euterpe edulis (Juçara) and Euterpe oleracea (Açaí) oxidise after harvesting, whereas almost no oxidation is observed in palmitos from Bactris gasipaes (Pupunha). Previous investigations showed that oxidation in Juçara and Açaí was mainly attributable to polyphenol oxidase (PPO; EC 1.14.18.1) activity. In this study, we partially purified PPOs from these three palmitos and analysed them for SDS activation, substrate specificity, inhibition by specific inhibitors, thermal stability, optimum pH and temperature conditions, Km and Ki. In addition, the total phenolic content and chlorogenic acid content were determined. Two partial cDNA sequences were isolated and sequenced from Açaí (EoPPO1) and Juçara (EePPO1). Semi-quantitative RT-PCR expression assays showed that Açaí and Juçara PPOs were strongly expressed in palmitos and weakly expressed in leaves. No amplification was observed for Pupunha samples. The lack of oxidation in the palmito Pupunha might be explained by the low PPO expression, low enzyme activity or the phenolic profile, particularly the low content of chlorogenic acid. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Efficacy and safety assessment of isolated ultrafiltration compared to intravenous diuretics for acutely decompensated heart failure: a systematic review with meta-analysis.

    Science.gov (United States)

    De Vecchis, R; Esposito, C; Ariano, C

    2014-04-01

    Intravenous diuretics at relatively high doses are currently used for treating acute decompensated heart failure (ADHF). However, the existence of harmful side effects diuretic-related, such as electrolyte abnormalities, symptomatic hypotension and marked neuro-hormonal activation have led researchers to implement alternative therapeutic tools such as isolated ultrafiltration (IUF). Our study aimed to compare intravenous diuretics vs. IUF as regards their respective efficacy and safety in ADHF patients through systematic review and meta-analysis of data derived from relevant randomized controlled trials. 6 studies grouping a total of 477 patients were included in the systematic review. By contrast, data from only three studies were pooled for the meta-analysis, because of different adopted outcomes or marked dissimilarities in the data presentation . Weight loss at 48 h was greater in IUF group compared to the diuretics group [weighted mean difference (WMD)=1.77 kg; 95%CI: 1.18-2.36 kg; Pdiuretics group (WMD=1.2 liters; 95%CI: 0.73-1.67 liters; P 0.3 mg/dl at 48 hours, was similar to the one found in the diuretics group (OR=1.33; 95% CI: 0.81-2.16 P=0.26). On the basis of this meta-analysis, IUF induced greater weight loss and larger fluid removal compared to iv diuretics in ADHF patients, whereas the probability of developing WRF was not significantly different in the comparison between iv diuretics and IUF.

  17. [Effects of synthetic antioxidant ionol on bioelectric activity of cardiomyocytes and arrhythmia in global ischemia and reperfusion of the isolated rat heart].

    Science.gov (United States)

    Belkina, L M; Vovk, V I; Meerson, F Z

    1992-04-01

    Isolated rat hearts were subjected to global ischemia (15 min) and reperfusion (20 min). Transmembrane potentials were recorded on the epicardial surface and contractile force was measured. Ischemia reduced the resting potential, the action potential (AP) amplitude and the AP duration (APD) in control animals. Pretreatment with synthetic antioxidant ionol (BHT, 50 mg/kg, per os) didn't influence the time course of changes in the resting potential and AP amplitude during ischemia, but significantly increased APD. In the pretreated group, 5 min after the aorta clamping, the APD at 50% and 90% levels of repolarization was 36% (p less than 0.05) and 13% (p less than 0.1) higher in comparison to the preischemic level and 10 min after clamping by 27% (p less than 0.1) and 29% (p less than 0.05), respectively. By the end of ischemia in the pretreated group, APD re-decreased almost to basal level, but in control group, it remained decreased. During reperfusion BHT improved the recovery of bioelectrical activity and the contractile function. The BHT 10-fold reduced the malignant arrhythmias duration and 2.5-fold the incidence of ventricular tachycardia and fibrillation during reperfusion. These results indicate that the induced by BHT increase in APD can contribute to the mechanism of BHT antiarrhythmic action.

  18. Ovarian hyperstimulation syndrome in gonadotropin-treated laboratory South African clawed frogs (Xenopus laevis).

    Science.gov (United States)

    Green, Sherril L; Parker, John; Davis, Corrine; Bouley, Donna M

    2007-05-01

    Ovarian hyperstimulation syndrome (OHS) is a rare but sometimes fatal iatrogenic complication of ovarian stimulation associated with the administration of exogenous gonadotropins to women undergoing treatment for infertility. Laboratory Xenopus spp are commonly treated with human chorionic gonadotropin (hCG) to stimulate ovulation and optimize the number of oocytes harvested for use in biomedical research. Here we report cases of OHS in 2 gonadotropin-treated laboratory Xenopus laevis. After receiving hCG, the frogs developed severe subcutaneous accumulation of fluid, coelomic distention, and whole-body edema and were unable to dive, although they continued to eat and swim. At postmortem examination, extensive subcutaneous edema was present; ascites and massive numbers of free-floating eggs were found in the coelomic cavity and in aberrant locations: around the heart-sac and adhered to the liver capsule. Whole-body edema, gross enlargement of the ovaries, ascites, and abdominal distention are findings comparable to those observed in women with OHS. The pathophysiology of OHS is thought to be related to hormonally induced disturbances of vasoactive mediators, one of which may be vascular endothelial growth factor secreted by theca and granulosa cells. We know of no other report describing OHSlike symptoms in gonadotropin-treated frogs, and the cases described here are 2 of the 3 we have observed at our respective institutions over the last 6 y. According to these results, OHS appears to be rare in gonadotropin-treated laboratory Xenopus. However, the condition should be included in the differential diagnosis for the bloated frog.

  19. FROG: The Fast And Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  20. Metabolomic profiling of Green Frogs exposed to Mixed Pesticides

    Data.gov (United States)

    U.S. Environmental Protection Agency — GC/MS data from the metabolomic profiling of green frog livers after exposure to pesticides and their mixtures. This dataset is associated with the following...

  1. Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

    Science.gov (United States)

    Zhang, Dian; Cui, Jianguo; Tang, Yezhong

    2012-01-01

    In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs) evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

  2. Plasticity of peripheral auditory frequency sensitivity in Emei music frog.

    Directory of Open Access Journals (Sweden)

    Dian Zhang

    Full Text Available In anurans reproductive behavior is strongly seasonal. During the spring, frogs emerge from hibernation and males vocalize for mating or advertising territories. Female frogs have the ability to evaluate the quality of the males' resources on the basis of these vocalizations. Although studies revealed that central single torus semicircularis neurons in frogs exhibit season plasticity, the plasticity of peripheral auditory sensitivity in frog is unknown. In this study the seasonally plasticity of peripheral auditory sensitivity was test in the Emei music frog Babina daunchina, by comparing thresholds and latencies of auditory brainstem responses (ABRs evoked by tone pips and clicks in the reproductive and non-reproductive seasons. The results show that both ABR thresholds and latency differ significantly between the reproductive and non-reproductive seasons. The thresholds of tone pip evoked ABRs in the non-reproductive season increased significantly about 10 dB than those in the reproductive season for frequencies from 1 KHz to 6 KHz. ABR latencies to waveform valley values for tone pips for the same frequencies using appropriate threshold stimulus levels are longer than those in the reproductive season for frequencies from 1.5 to 6 KHz range, although from 0.2 to 1.5 KHz range it is shorter in the non-reproductive season. These results demonstrated that peripheral auditory frequency sensitivity exhibits seasonal plasticity changes which may be adaptive to seasonal reproductive behavior in frogs.

  3. Is chytridiomycosis driving Darwin's frogs to extinction?

    Directory of Open Access Journals (Sweden)

    Claudio Soto-Azat

    Full Text Available Darwin's frogs (Rhinoderma darwinii and R. rufum are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9% of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans, all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9% was significantly lower than that found in other anurans (7.3%. The prevalence of infection (30% in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x(2 = 106.407, P<0.001. This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further.

  4. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    Science.gov (United States)

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

  5. Enlarged Heart

    Science.gov (United States)

    ... rheumatic fever, a heart defect, infections (infectious endocarditis), connective tissue disorders, certain medications or radiation treatments for cancer, your heart may enlarge. Disease of the heart ...

  6. The kinetics of {beta}-methyl-substituted labelled fatty acids in ischaemic myocardium: an analysis in man and with a blood-perfused isolated heart model

    Energy Technology Data Exchange (ETDEWEB)

    Marie, P.Y.; Ayalew, A.; Hassan, N.; Olivier, P.; Karcher, G.; Bertrand, A. [Dept. of Nuclear Medicine, UPRES EA, Nancy (France); Menu, P. [Dept. of Hematology and Physiology, University Henri Poincare, Nancy (France); Angioi, M.; Mertes, P.M.; Danchin, N. [Dept. of Cardiology, UPRES EA, Nancy (France); Fagret, D. [Dept. of Nuclear Medicine, Grenoble (France); Pasqualini, R. [CIS Bio International, Gif-sur-Yvette (France)

    1999-05-01

    {beta}-Methyl-substituted free fatty acids (FFAs) have been developed for myocardial single-photon emission tomography (SPET) imaging, but little is known about their kinetics in ischaemic conditions. The aim of this study was to determine the changes in the myocardial kinetics of a {beta}-methyl-branched FFA, [{sup 123}I]16-iodo-3-methyl-hexadecanoic acid (MIHA), under ischaemic conditions. The kinetics of MIHA were analysed: (a) using a blood-perfused isolated heart model subjected to moderate ischaemia (50% flow reduction) and (b) in patients who had an exercise thallium-201 SPET defect corresponding to either necrotic (n = 13) or chronically ischaemic and viable (n = 15) myocardium, and who underwent two consecutive SPET studies after MIHA injection. In animals, the myocardial early retention fraction of MIHA, but not its clearance rate, was dependent on coronary flow, the early retention fraction being higher in ischaemic than in normoxic conditions (0.24{+-}0.10 vs 0.14{+-}0.04, P = 0.004). In the patient SPET studies, the uptake of MIHA calculated in ischaemic and viable areas (G1: 74%{+-}9% of maximal left ventricular value) was different from that calculated in necrotic (G2: 59%{+-}7%, P<0.001) or normal (G3: 88{+-}6%, P<0.001) areas. By contrast, MIHA-clearance calculated between the two consecutive SPET studies was not different in G1, G2 and G3. Unlike in the case of other FFAs, the myocardial clearance of MIHA is not decreased by ischaemia. However, the early retention of MIHA is increased in the case of a moderate reduction in coronary flow, a property which might help in the detection of viability in chronically ischaemic myocardium. (orig.) With 5 figs., 3 tabs., 44 refs.

  7. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium

    DEFF Research Database (Denmark)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel

    2015-01-01

    Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore......, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated...... form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C...

  8. Female preferences for aposematic signal components in a polymorphic poison frog

    NARCIS (Netherlands)

    Maan, Martine E.; Cummings, Molly E.

    Aposematic signals may be subject to conflicting selective pressures from predators and conspecifics. We studied female preferences for different components of aposematic coloration in the polymorphic poison frog Oophaga pumilio across several phenotypically distinct populations. This frog shows

  9. Determination of age, longevity and age at reproduction of the frog ...

    Indian Academy of Sciences (India)

    Unknown

    separately in plastic bags and placed in 5 different aquaria. Each frog was anaesthetized (using anaesthetic ether), the body mass ... bone of each frog, were measured using an ocular .... One of the problems generally associated with skeleto-.

  10. Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

    DEFF Research Database (Denmark)

    Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

    1995-01-01

    Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

  11. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  12. Frogs Call at a Higher Pitch in Traffic Noise

    Directory of Open Access Journals (Sweden)

    Kirsten M. Parris

    2009-06-01

    Full Text Available Male frogs call to attract females for mating and to defend territories from rival males. Female frogs of some species prefer lower-pitched calls, which indicate larger, more experienced males. Acoustic interference occurs when background noise reduces the active distance or the distance over which an acoustic signal can be detected. Birds are known to call at a higher pitch or frequency in urban noise, decreasing acoustic interference from low-frequency noise. Using Bayesian linear regression, we investigated the effect of traffic noise on the pitch of advertisement calls in two species of frogs, the southern brown tree frog (Litoria ewingii and the common eastern froglet (Crinia signifera. We found evidence that L. ewingii calls at a higher pitch in traffic noise, with an average increase in dominant frequency of 4.1 Hz/dB of traffic noise, and a total effect size of 123 Hz. This frequency shift is smaller than that observed in birds, but is still large enough to be detected by conspecific frogs and confer a significant benefit to the caller. Mathematical modelling predicted a 24% increase in the active distance of a L. ewingii call in traffic noise with a frequency shift of this size. Crinia signifera may also call at a higher pitch in traffic noise, but more data are required to be confident of this effect. Because frog calls are innate rather than learned, the frequency shift demonstrated by L. ewingii may represent an evolutionary adaptation to noisy conditions. The phenomenon of frogs calling at a higher pitch in traffic noise could therefore constitute an intriguing trade-off between audibility and attractiveness to potential mates.

  13. THE MOCHE BOTANICAL FROG (La rana botánica mochica)

    OpenAIRE

    Donna McClelland †

    2011-01-01

    Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog perform...

  14. Ciguatoxin enhances quantal transmitter release from frog motor nerve terminals.

    Science.gov (United States)

    Molgó, J.; Comella, J. X.; Legrand, A. M.

    1990-01-01

    1. Ciguatoxin (CTX), a marine toxin produced by the benthic dinoflagellate Gambierdiscus toxicus, is responsible for a complex endemic disease in man known as ciguatera fish poisoning. In the present study we have investigated the effects of purified CTX extracted for Gymnothorax javanicus moray-eel liver on frog isolated neuromuscular preparations with conventional electrophysiological techniques. 2. CTX (1-2.5 nM) applied to cutaneous pectoris nerve-muscle preparations induced, after a short delay, spontaneous fibrillations of the muscle fibres that could be suppressed with 1 microM tetrodotoxin (TTX) or by formamide to uncouple excitation-contraction. 3. In preparations treated with formamide, CTX (1-2.5 nM) caused either spontaneous or repetitive muscle action potentials (up to frequencies of 60-100 Hz) in response to a single nerve stimulus. Recordings performed at extrajunctional regions of the muscle membrane revealed that during the repetitive firing a prolongation of the repolarizing phase of the action potential occurred. At junctional sites the repetitive action potentials were triggered by repetitive endplate potentials (e.p.ps). 4. CTX (2.5 nM) caused a TTX-sensitive depolarization of the muscle membrane. 5. In junctions equilibrated in solutions containing high Mg2+ + low Ca2+, addition of CTX (1.5 nM) first induced an average increase of 239 +/- 36% in the mean quantal content of e.p.ps. Subsequently CTX reduced and finally blocked nerve-evoked transmitter release irreversibly. 6. CTX (1.5-2.5 nM) increased the frequency of miniature endplate potentials (m.e.p.ps) in junctions bathed either in normal Ringer, low Ca2(+)-high Mg2+ medium or in a nominally Ca2(+)-free solution containing EGTA.2+ Extensive washing with toxin-free solutions did not reverse the effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1972891

  15. Antitumor and angiostatic peptides from frog skin secretions.

    Science.gov (United States)

    van Zoggel, Hanneke; Hamma-Kourbali, Yamina; Galanth, Cécile; Ladram, Ali; Nicolas, Pierre; Courty, José; Amiche, Mohamed; Delbé, Jean

    2012-01-01

    The discovery of new molecules with potential antitumor activity continues to be of great importance in cancer research. In this respect, natural antimicrobial peptides isolated from various animal species including humans and amphibians have been found to be of particular interest. Here, we report the presence of two anti-proliferative peptides active against cancer cells in the skin secretions of the South American tree frog, Phyllomedusa bicolor. The crude skin exudate was fractioned by size exclusion gel followed by reverse-phase HPLC chromatography. After these two purification steps, we identified two fractions that exhibited anti-proliferative activity. Sequence analysis indicated that this activity was due to two antimicrobial α-helical cationic peptides of the dermaseptin family (dermaseptins B2 and B3). This result was confirmed using synthetic dermaseptins. When tested in vitro, synthetic B2 and B3 dermaseptins inhibited the proliferation of the human prostatic adenocarcinoma PC-3 cell line by more than 90%, with an EC(50) of around 2-3 μM. No effect was observed on the growth of the NIH-3T3 non-tumor mouse cell line with Drs B2, whereas a slight inhibiting effect was observed with Drs B3 at high dose. In addition, the two fractions obtained after size exclusion chromatography also inhibited PC-3 cell colony formation in soft agar. Interestingly, inhibition of the proliferation and differentiation of activated adult bovine aortic endothelial cells was observed in cells treated with these two fractions. Dermaseptins B2 and B3 could, therefore, represent interesting new pharmacological molecules with antitumor and angiostatic properties for the development of a new class of anticancer drugs.

  16. Passive ionic properties of frog retinal pigment epithelium.

    Science.gov (United States)

    Miller, S S; Steinberg, R H

    1977-09-15

    The isolated pigment epithelium and choroid of frog was mounted in a chamber so that the apical surfaces of the epithelial cells and the choroid were exposed to separate solutions. The apical membrane of these cells was penetrated with microelectrodes and the mean apical membrane potential was --88 mV. The basal membrane potential was depolarized by the amount of the transepithelial potential (8--20 mV). Changes in apical and basal cell membrane voltage were produced by changing ion concentrations on one or both sides of the tissue. Although these voltage changes were altered by shunting and changes in membrane resistance, it was possible to estimate apical and basal cell membrane and shunt resistance, and the relative ionic conductance Ti of each membrane. For the apical membrane: TK approximately equal to 0.52, THCO3 approximately equal to 0.39 and TNa approximately equal to 0.05, and its specific resistance was estimated to be 6000--7000 omega cm2. For the basal membrane: TK approximately equal to 0.90 and its specific resistance was estimated to be 400--1200 omega cm2. From the basal potassium voltage responses the intracellular potassium concentration was estimated at 110 mM. The shunt resistance consisted of two pathways: a paracellular one, due to the junctional complexes and another, around the edge of the tissue, due to the imperfect nature of the mechanical seal. In well-sealed tissues, the specific resistance of the shunt was about ten times the apical plus basal membrane specific resistances. This epithelium, therefore, should be considered "tight". The shunt pathway did not distinguish between anions (HCO--3, Cl--, methylsulfate, isethionate) but did distinguish between Na+ and K+.

  17. Post-evaluation of the neurophaties treatment post-trauma with therapeutic laser. Model in sciatic nerve of frog

    Science.gov (United States)

    Escobar, Antonio S.; Ocampo, Arcelia F. M.; Hernández, María G. H.; Jasso, José L. C.; Lira, Maricela O. F.; Flores, Mariana A.; Balderrama, Vicente L.

    2010-05-01

    The purpose of this study was to evaluate the compound nerve action potential amplitude and latency measured to determine the degree of myelination and the number of fibers stimulated in a model of stimulated frog sciatic nerve laser at 810 nm as perioperative treatment after injury. It used 30 bullfrogs (Rana catesbeiana) to obtain 60 sciatic nerves forming four groups, groups 1 and 2 worked with nerves in vitro, were dissected in humid chambers for placing isolated organ, was recorded on compound nerve action potential, the second group laser was applied at 24, 48, 72, 96 and 120 hours and at the same time were placed in 10% formalin. Groups 3 and 4 are worked in vivo localizing the nerve and causing damage through compression, occurred over the compound nerve action potential to assess the degree of myelination and the number of fibers stimulated, the group 4 was applied to 810 nm laser (500 Hz, 10 J, 200 mW) after injury, after 48 hours, three frogs were sacrificed by introducing the nerves in 10% formalin. The latency recorded by stimulating the sciatic nerve of frog to 0.5 mA and 100 ms in groups 1 and 2 show significant differences (p000), as to the extent, if any statistically significant difference. (pparesthesia (post-traumatic neuropathy).

  18. Post-evaluation of the neurophaties treatment post-trauma with therapeutic laser. Model in sciatic nerve of frog

    International Nuclear Information System (INIS)

    Escobar, Antonio S.; Ocampo, Arcelia F. M.; Hernandez, Maria G. H.; Jasso, Jose L. C.; Lira, Maricela O. F.; Flores, Mariana A.; Balderrama, Vicente L.

    2010-01-01

    The purpose of this study was to evaluate the compound nerve action potential amplitude and latency measured to determine the degree of myelination and the number of fibers stimulated in a model of stimulated frog sciatic nerve laser at 810 nm as perioperative treatment after injury. It used 30 bullfrogs (Rana catesbeiana) to obtain 60 sciatic nerves forming four groups, groups 1 and 2 worked with nerves in vitro, were dissected in humid chambers for placing isolated organ, was recorded on compound nerve action potential, the second group laser was applied at 24, 48, 72, 96 and 120 hours and at the same time were placed in 10% formalin. Groups 3 and 4 are worked in vivo localizing the nerve and causing damage through compression, occurred over the compound nerve action potential to assess the degree of myelination and the number of fibers stimulated, the group 4 was applied to 810 nm laser (500 Hz, 10 J, 200 mW) after injury, after 48 hours, three frogs were sacrificed by introducing the nerves in 10% formalin. The latency recorded by stimulating the sciatic nerve of frog to 0.5 mA and 100 ms in groups 1 and 2 show significant differences (p 000), as to the extent, if any statistically significant difference. (p<0.001 and p<0.000). The laser produces a favorable response in the treatment of paresthesia (post-traumatic neuropathy).

  19. Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

    Science.gov (United States)

    Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

    2005-01-01

    We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

  20. Tourism and the Conservation of Critically Endangered Frogs

    Science.gov (United States)

    Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

    2012-01-01

    Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

  1. Frog sound identification using extended k-nearest neighbor classifier

    Science.gov (United States)

    Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

    2017-09-01

    Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

  2. Taurine biosynthesis in frog retina: effects of light and dark adaptations

    International Nuclear Information System (INIS)

    Nishimura, C.; Ida, S.; Kuriyama, K.

    1983-01-01

    The retinal uptake and metabolism of cysteine, a precursor for taurine biosynthesis, were analysed using the bull frog. The [ 14 C] cysteine uptake into isolated retina had some specific properties: It was rather temperature independent, required Na ions, was inhibited by ouabain but not by dinitrophenol, and exhibited saturation kinetics composed of two components. When retinal homogenate was incubated with 12-30 microM of L-[U- 14 C]cysteine, the accumulation of labeled alanine, cysteine sulfinic acid (CSA), cysteic acid (CA), hypotaurine, and taurine was detected. The metabolic conversions of [ 14 C] cysteine to labeled alanine, hypotaurine, and taurine were linear over 90 minutes. Prolonged light adaptation (3 weeks) induced a significant reduction in the formation of labeled CA, CSA, hypotaurine, and taurine from [ 14 C] cysteine. On the other hand, it was found that in dark-adapted retinae, the formation of labeled taurine from [ 14 C] cysteine increased significantly in spite of the reduction in the formation of labeled CA. These results indicate that biosynthetic pathways exist for taurine from cysteine in frog retina, and that these metabolic pathways are involved in the regulation of retinal taurine content under continuous visual adaptation

  3. Glaciations, gradients, and geography: multiple drivers of diversification of bush frogs in the Western Ghats Escarpment

    Science.gov (United States)

    Menezes, Riya C.; Jayarajan, Aditi; Shanker, Kartik

    2016-01-01

    The historical processes underlying high diversity in tropical biodiversity hotspots like the Western Ghats of Peninsular India remain poorly understood. We sampled bush frogs on 13 massifs across the Western Ghats Escarpment and examined the relative influence of Quaternary glaciations, ecological gradients and geological processes on the spatial patterns of lineage and clade diversification. The results reveal a large in situ radiation (more than 60 lineages), exhibiting geographical structure and clade-level endemism, with two deeply divergent sister clades, North and South, highlighting the biogeographic significance of an ancient valley, the Palghat Gap. A majority of the bush frog sister lineages were isolated on adjacent massifs, and signatures of range stasis provide support for the dominance of geological processes in allopatric speciation. In situ diversification events within the montane zones (more than 1800 m) of the two highest massifs suggest a role for climate-mediated forest-grassland persistence. Independent transitions along elevational gradients among sub-clades during the Miocene point to diversification along the elevational gradient. The study highlights the evolutionary significance of massifs in the Western Ghats with the high elevations acting as centres of lineage diversification and the low- and mid-elevations of the southern regions, with deeply divergent lineages, serving as museums. PMID:27534957

  4. The electrical properties of auditory hair cells in the frog amphibian papilla.

    Science.gov (United States)

    Smotherman, M S; Narins, P M

    1999-07-01

    The amphibian papilla (AP) is the principal auditory organ of the frog. Anatomical and neurophysiological evidence suggests that this hearing organ utilizes both mechanical and electrical (hair cell-based) frequency tuning mechanisms, yet relatively little is known about the electrophysiology of AP hair cells. Using the whole-cell patch-clamp technique, we have investigated the electrical properties and ionic currents of isolated hair cells along the rostrocaudal axis of the AP. Electrical resonances were observed in the voltage response of hair cells harvested from the rostral and medial, but not caudal, regions of the AP. Two ionic currents, ICa and IK(Ca), were observed in every hair cell; however, their amplitudes varied substantially along the epithelium. Only rostral hair cells exhibited an inactivating potassium current (IA), whereas an inwardly rectifying potassium current (IK1) was identified only in caudal AP hair cells. Electrically tuned hair cells exhibited resonant frequencies from 50 to 375 Hz, which correlated well with hair cell position and the tonotopic organization of the papilla. Variations in the kinetics of the outward current contribute substantially to the determination of resonant frequency. ICa and IK(Ca) amplitudes increased with resonant frequency, reducing the membrane time constant with increasing resonant frequency. We conclude that a tonotopically organized hair cell substrate exists to support electrical tuning in the rostromedial region of the frog amphibian papilla and that the cellular mechanisms for frequency determination are very similar to those reported for another electrically tuned auditory organ, the turtle basilar papilla.

  5. Apomorphine effects on frog locomotor behavior.

    Science.gov (United States)

    Chu, Joanne; Wilczynski, Walter

    2007-05-16

    The neuroanatomical pathways of the DA systems have been shown to be largely conserved across many vertebrate taxa. It is less certain whether the structural similarities seen between mammals and amphibians reflect a similar functional homology. DA is well known for its role in facilitating motor behaviors in mammals. We examined whether a similar role for DA exists in amphibians using the Northern Leopard Frog (Rana pipiens). We investigated the effects of the nonspecific DA agonist, apomorphine (APO) on a complex motor task that included two distinct components known to be differentially modulated by DA in mammals: swimming and climbing. We demonstrated that a high single dose of APO (20 mg/kg, body weight) strongly increased the amount of time spent completing the motor task. Furthermore, we showed that although APO did not significantly alter several aspects of swimming behavior, two aspects of climbing behavior were disrupted. Both climbing speed and climbing ability were impaired by APO treatment. These results increase our understanding of DA function in amphibians and add to our understanding of structure-function homologies of dopamine function across vertebrate taxa.

  6. Xenopus: An Emerging Model for Studying Congenital Heart Disease

    Science.gov (United States)

    Kaltenbrun, Erin; Tandon, Panna; Amin, Nirav M.; Waldron, Lauren; Showell, Chris; Conlon, Frank L.

    2011-01-01

    Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well-studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes. PMID:21538812

  7. Heart Failure

    Science.gov (United States)

    Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

  8. Landscape genetics of high mountain frog metapopulations

    Science.gov (United States)

    Murphy, M.A.; Dezzani, R.; Pilliod, D.S.; Storfer, A.

    2010-01-01

    Explaining functional connectivity among occupied habitats is crucial for understanding metapopulation dynamics and species ecology. Landscape genetics has primarily focused on elucidating how ecological features between observations influence gene flow. Functional connectivity, however, may be the result of both these between-site (landscape resistance) landscape characteristics and at-site (patch quality) landscape processes that can be captured using network based models. We test hypotheses of functional connectivity that include both between-site and at-site landscape processes in metapopulations of Columbia spotted frogs (Rana luteiventris) by employing a novel justification of gravity models for landscape genetics (eight microsatellite loci, 37 sites, n = 441). Primarily used in transportation and economic geography, gravity models are a unique approach as flow (e.g. gene flow) is explained as a function of three basic components: distance between sites, production/attraction (e.g. at-site landscape process) and resistance (e.g. between-site landscape process). The study system contains a network of nutrient poor high mountain lakes where we hypothesized a short growing season and complex topography between sites limit R. luteiventris gene flow. In addition, we hypothesized production of offspring is limited by breeding site characteristics such as the introduction of predatory fish and inherent site productivity. We found that R. luteiventris connectivity was negatively correlated with distance between sites, presence of predatory fish (at-site) and topographic complexity (between-site). Conversely, site productivity (as measured by heat load index, at-site) and growing season (as measured by frost-free period between-sites) were positively correlated with gene flow. The negative effect of predation and positive effect of site productivity, in concert with bottleneck tests, support the presence of source-sink dynamics. In conclusion, gravity models provide a

  9. Identification and characterization of two dermorphins from skin extracts of the Amazonian frog Phyllomedusa bicolor.

    Science.gov (United States)

    Mignogna, G; Severini, C; Simmaco, M; Negri, L; Erspamer, G F; Kreil, G; Barra, D

    1992-05-11

    Skin extracts of South American hylid frogs of the subfamily Phyllomedusinae contain dermorphins and deltorphins, opioid heptapeptides highly selective for either mu or delta receptors. In all these peptides, a D-amino acid is present in the second position. The structure of the precursors for Ala-deltorphins was recently deduced from cloned cDNAs derived from skin of Phyllomedusa bicolor (Richter et al. (1990) Proc. Natl. Acad. Sci. USA 87, 4836-4839). From the amino acid sequence of these precursors, the existence of three peptides related to dermorphin could be predicted. From methanol extracts of skin of Ph. bicolor we have isolated two of these peptides, [Lys7]dermorphin-OH and [Trp4,Asn7]dermorphin-OH. The biological activity of these new dermorphins and their amidated counterparts is presented.

  10. Modification of permeability of frog perineurium to [14C]-sucrose by stretch and hypertonicity

    International Nuclear Information System (INIS)

    Weerasuriya, A.; Rapoport, S.I.; Taylor, R.E.

    1979-01-01

    An in vitro method has been developed to determine quantitatively the permeability of the perineurium to radiotracers at room temperature. The permeability to [ 14 C]sucrose of the isolated perineurium of the sciatic nerve of the frog, Rana pipiens, was measured at rest length, when the perineurium was stretched and after the perineurium had been subjected to hypertonic treatment. Mean permeability at rest length was calculated to be 5.6 +- 0.27 (S.E.M., n=45)x10 -7 cm/sec, and both stretch and hypertonic treatment increased the permeability. A 10% stretch increased permeability reversibly, whereas a 20% stretch or immersion of the perineurium in a hypertonic bath increased permeability irreversibly. Altered permeability under these conditions might be related to changes in the ultrastructure of tight junctions in the perineurium. (Auth.)

  11. Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae Ontogenetic polychromatism in marsupial frogs (Anura: Hylidae

    Directory of Open Access Journals (Sweden)

    Duellman William E.

    1986-12-01

    Full Text Available Color polymorphism is common in many species of marsupial frogs.  Extreme cases of pattern polymorphism are documented in four species. In Amphignathodon guentheri, Castrotheca aureomaculata, G. qriswoldi, and G. helenae juveniles are known to have only one color morph, where as two or more patterns exist in adults. In these species, polymorphism apparently develops ontogenetically. El polimorfismo cromático es común a algunas especies de sapos marsupiales. Casos extremos del modelo de polimorfismo son evidentes en cuatro especies Amphignathodon guentheri, Gastrotheca aureomaculata, G. griswoldi, y G. helenae. En estas especies, se sabe que los juveniles tienen sólo un morfo de color; el polimorfismo, al parecer, se desarrolla ontogenéticamente.

  12. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  13. Speculations on colonizing success of the African clawed frog ...

    African Journals Online (AJOL)

    1991-12-12

    Dec 12, 1991 ... Robinson. Ann. Durban Mus. 1: 167-170. SMITH, J.L.B. 1961. Fishes of the family Apogonidae of the western Indian Ocean and the Red Sea.lchlhyol. .... J. Herp. 12: 391-396. BAIRD, T. 1983. Influence of social and predatory stimulus on the air-breathing behavior of the African clawed frog,. Xenopus laevis.

  14. Natural disturbance reduces disease risk in endangered rainforest frog populations.

    Science.gov (United States)

    Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

    2015-08-21

    Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

  15. Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

    Science.gov (United States)

    Roelants, Kim; Bossuyt, Franky

    2005-02-01

    Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

  16. Choosing the safest route: frog orientation in an agricultural landscape

    NARCIS (Netherlands)

    Mazerolle, M.J.; Vos, C.C.

    2006-01-01

    Orientation is a key component to successful movements between habitats. We hypothesized that barren agricultural landscapes hinder the ability of frogs to orient and move between habitats. Specifically, we predicted that when presented with a choice between a short route through a hostile

  17. Frogs from the Leeward group, Venezuela and eastern Colombia

    NARCIS (Netherlands)

    Brongersma, L.D.

    1948-01-01

    The present notes deal with a small collection of frogs that was made by Dr. P. WAGENAAR HUMMELINCK during his visits to the islands of the Leeward Group, Venezuela and Eastern Colombia. I have included in this study the specimens of Pleurodema brachyops (Cope) already present in the Rijksmuseum van

  18. Taxonomic variation in oviposition by tailed frogs (Aschaphus spp.).

    Science.gov (United States)

    Nancy E. Karraker; David S. Pilliod; Michael J. Adams; Evelyn L. Bull; Paul Stephen Corn; Lowell V. Diller; Linda A. Dupuis; Marc P. Hayes; Blake R. Hossack; Garth R. Hodgson; Erin J. Hyde; Kirk Lohman; Bradford R. Norman; Lisa M. Ollivier; Christopher A. Pearl; Charles R. Peterson

    2006-01-01

    Tailed frogs (Ascaphus spp.) oviposit in cryptic locations in streams of the Pacific Northwest and Rocky Mountains. This aspect of their life history has restricted our understanding of their reproductive ecology. The recent split of A. montanus in the Rocky Mountains from A. truei was based on molecular...

  19. A new grass frog from Namibia | Channing | African Zoology

    African Journals Online (AJOL)

    A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that ...

  20. Antifungal activity of epithelial secretions from selected frog species ...

    African Journals Online (AJOL)

    This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions ...

  1. Vectorcardiogram of the 'Man-Frog' | Skowron | South African ...

    African Journals Online (AJOL)

    Chest electrodes from a man and from a frog are connected simultaneously to an oscilloscope - the one to the vertical and the other to the horizontal plates - and the resulting display observed. It consists of a loop, the interpretation of which is discussed, and the conclusion is reached that the presently held vector theory ...

  2. Macro and Trace Element Accumulation in Edible Crabs and Frogs ...

    African Journals Online (AJOL)

    The tissue accumulation of five macroelements (Na, Mg, K, Ca, Fe) and twelve trace elements (Vd, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Pb) were assessed in the organs of the edible frogs; Xenopus laevis and Rana esculentus, and whole body of the crab, Callinestes caught from Alaro Stream Floodplain (Ibadan, ...

  3. Foraging behaviour in tadpoles of the bronze frog Rana temporalis ...

    Indian Academy of Sciences (India)

    Unknown

    The ability of bronze frog Rana temporalis tadpoles (pure or mixed parental lines) to ... less of whether they are siblings or non-siblings in a group, which correlates well with ..... Sutherland W J and Parker G A 1992 The relationship between.

  4. Elastic modulus of tree frog adhesive toe pads.

    Science.gov (United States)

    Barnes, W Jon P; Goodwyn, Pablo J Perez; Nokhbatolfoghahai, Mohsen; Gorb, Stanislav N

    2011-10-01

    Previous work using an atomic force microscope in nanoindenter mode indicated that the outer, 10- to 15-μm thick, keratinised layer of tree frog toe pads has a modulus of elasticity equivalent to silicone rubber (5-15 MPa) (Scholz et al. 2009), but gave no information on the physical properties of deeper structures. In this study, micro-indentation is used to measure the stiffness of whole toe pads of the tree frog, Litoria caerulea. We show here that tree frog toe pads are amongst the softest of biological structures (effective elastic modulus 4-25 kPa), and that they exhibit a gradient of stiffness, being stiffest on the outside. This stiffness gradient results from the presence of a dense network of capillaries lying beneath the pad epidermis, which probably has a shock absorbing function. Additionally, we compare the physical properties (elastic modulus, work of adhesion, pull-off force) of the toe pads of immature and adult frogs.

  5. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  6. Research on moving object detection based on frog's eyes

    Science.gov (United States)

    Fu, Hongwei; Li, Dongguang; Zhang, Xinyuan

    2008-12-01

    On the basis of object's information processing mechanism with frog's eyes, this paper discussed a bionic detection technology which suitable for object's information processing based on frog's vision. First, the bionics detection theory by imitating frog vision is established, it is an parallel processing mechanism which including pick-up and pretreatment of object's information, parallel separating of digital image, parallel processing, and information synthesis. The computer vision detection system is described to detect moving objects which has special color, special shape, the experiment indicates that it can scheme out the detecting result in the certain interfered background can be detected. A moving objects detection electro-model by imitating biologic vision based on frog's eyes is established, the video simulative signal is digital firstly in this system, then the digital signal is parallel separated by FPGA. IN the parallel processing, the video information can be caught, processed and displayed in the same time, the information fusion is taken by DSP HPI ports, in order to transmit the data which processed by DSP. This system can watch the bigger visual field and get higher image resolution than ordinary monitor systems. In summary, simulative experiments for edge detection of moving object with canny algorithm based on this system indicate that this system can detect the edge of moving objects in real time, the feasibility of bionic model was fully demonstrated in the engineering system, and it laid a solid foundation for the future study of detection technology by imitating biologic vision.

  7. Measurement and Evaluation of Wear Frogs Switches ŽSR

    Directory of Open Access Journals (Sweden)

    Urda Ján

    2014-05-01

    Full Text Available This paper deals with the measurement and evaluation of wear frogs switches ZSR. One of the main problems is the oversize wear. The possibilities analysis of this problem is offered through a set of switches and monitoring of selected parameters. One of these parameters is also monitoring the vertical wear

  8. Comparison of 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA) metabolism and kinetics in the isolated rat heart

    International Nuclear Information System (INIS)

    DeGrado, T.R.; Ng, C.K.; Raffel, D.M.; Holden, J.E.

    1988-01-01

    Time courses of radioactivity (residue curves) were obtained following bolus injection into working rat hearts of two 125 I-labeled long chain fatty acids: 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA). Residue curves were analyzed in terms of a rapid vascular washout component, an early tissue clearance component, and a very slow late component. For IHDA and IPPA in control hearts, early myocardial clearance kinetics were limited by the diffusion of catabolites. Sensitivity of the kinetics to impaired fatty acid oxidation was examined by pretreatment of animals with 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). Decreased fatty acid oxidation was indicated in IHDA and IPPA residue curves by a decrease in the relative size of the early clearance component. Analysis of radiolabeled species in coronary effluent and heart homogenates showed that back diffusion of IPPA was slower than that of IHDA; this discrepancy was most apparent in POCA hearts. In vitro binding assays suggested higher tissue: Albumin relative affinity for IPPA than for IHDA. Thus, IPPA early clearance kinetics were more closely related to the clearance of labeled (catabolite(s)) and were therefore more sensitive to the oxidation rate of long chain fatty acids. (orig.)

  9. High frequency of submicroscopic genomic aberrations detected by tiling path array comparative genome hybridisation in patients with isolated congenital heart disease

    DEFF Research Database (Denmark)

    Erdogan, F; Larsen, Lars Allan; Zhang, L

    2008-01-01

    BACKGROUND: Congenital heart disease (CHD) is the most common birth defect and affects nearly 1% of newborns. The aetiology of CHD is largely unknown and only a small percentage can be assigned to environmental risk factors such as maternal diseases or exposure to mutagenic agents during pregnanc...

  10. Comparison of 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA) metabolism and kinetics in the isolated rat heart

    Energy Technology Data Exchange (ETDEWEB)

    DeGrado, T.R.; Ng, C.K.; Raffel, D.M.; Holden, J.E.

    1988-12-01

    Time courses of radioactivity (residue curves) were obtained following bolus injection into working rat hearts of two /sup 125/I-labeled long chain fatty acids: 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA). Residue curves were analyzed in terms of a rapid vascular washout component, an early tissue clearance component, and a very slow late component. For IHDA and IPPA in control hearts, early myocardial clearance kinetics were limited by the diffusion of catabolites. Sensitivity of the kinetics to impaired fatty acid oxidation was examined by pretreatment of animals with 2(5(4-chlorophenyl)pentyl)oxirane-2-carboxylate (POCA). Decreased fatty acid oxidation was indicated in IHDA and IPPA residue curves by a decrease in the relative size of the early clearance component. Analysis of radiolabeled species in coronary effluent and heart homogenates showed that back diffusion of IPPA was slower than that of IHDA; this discrepancy was most apparent in POCA hearts. In vitro binding assays suggested higher tissue: Albumin relative affinity for IPPA than for IHDA. Thus, IPPA early clearance kinetics were more closely related to the clearance of labeled (catabolite(s)) and were therefore more sensitive to the oxidation rate of long chain fatty acids.

  11. Comparison of 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA) metabolism and kinetics in the isolated rat heart.

    Science.gov (United States)

    DeGrado, T R; Holden, J E; Ng, C K; Raffel, D M; Gatley, S J

    1988-01-01

    Time courses of radioactivity (residue curves) were obtained following bolus injection into working rat hearts of two 125I-labeled long chain fatty acids: 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA). Residue curves were analyzed in terms of a rapid vascular washout component, an early tissue clearance component, and a very slow late component. For IHDA and IPPA in control hearts, early myocardial clearance kinetics were rate limited by the diffusion of catabolites. Sensitivity of the kinetics to impaired fatty acid oxidation was examination by pretreatment of animals with 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). Decreased fatty acid oxidation was indicated in IHDA and IPPA residue curves by a decrease in the relative size of the early clearance component. Analysis of radiolabeled species in coronary effluent and heart homogenates showed that back diffusion of IPPA was slower than that of IHDA; this discrepancy was most apparent in POCA hearts. In vitro binding assays suggested higher tissue:albumin relative affinity for IPPA than for IHDA. Thus, IPPA early clearance kinetics were more closely related to the clearance of labeled catabolite(s) and were therefore more sensitive to the oxidation rate of long chain fatty acids.

  12. COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

    Science.gov (United States)

    The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

  13. Heart Diseases

    Science.gov (United States)

    ... you're like most people, you think that heart disease is a problem for others. But heart disease is the number one killer in the ... of disability. There are many different forms of heart disease. The most common cause of heart disease ...

  14. Heart Transplantation

    Science.gov (United States)

    A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The ...

  15. Molecular cloning of skin peptide precursor-encoding cDNAs from tibial gland secretion of the Giant Monkey Frog, Phyllomedusa bicolor (Hylidae, Anura).

    Science.gov (United States)

    König, Enrico; Clark, Valerie C; Shaw, Chris; Bininda-Emonds, Olaf R P

    2012-12-01

    The skins of phyllomedusine frogs have long been considered as being tremendously rich sources of bioactive peptides. Previous studies of both peptides and cloning of their precursor encoding cDNAs have relied upon methanolic skin extracts or the dissected skins of recently deceased specimens and have not considered the different glands in isolation. We therefore focused our attention on the tibial gland of the Giant Monkey Frog, Phyllomedusa bicolor and constructed a cDNA library from the skin secretion that was obtained via mechanical stimulation of this macrogland. Using shotgun cloning, four precursors encoding host-defense peptides were identified: two archetypal dermaseptins, a phyllokinin and a phylloseptin that is new for this species but has been recently described from the Waxy Monkey Leaf Frog, Phyllomedusa sauvagii. Our study is the first to report defensive peptides specifically isolated from anuran tibial glands, confirming the hypothesis that these glands also contribute to chemical defense. Moreover, the discovery of novel compounds for this otherwise very well characterized species suggests that this largely neglected gland might possess a different cocktail of secretions from glands elsewhere in the same animal. We will also discuss some evolutionary implications of our findings with respect to the adaptive plasticity of secretory glands. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. An experimental test for age-related improvements in reproductive performance in a frog that cares for its young

    Science.gov (United States)

    Dugas, Matthew B.; Moore, Michael P.; Wamelink, Caitlin N.; Richards-Zawacki, Corinne L.; Martin, Ryan A.

    2015-10-01

    Reproductive performance often increases with age in long-lived iteroparous organisms, a pattern that can result from within-individual increases in effort and/or competence. In free-living populations, it is typically difficult to distinguish these mechanisms or to isolate particular features of reproduction-influencing outcomes. In captive Oophaga pumilio, a frog in which mothers provide extended offspring provisioning via trophic eggs, we experimentally manipulated the age at which females started breeding and then monitored them across repeated reproductive events. This experiment allowed us to decouple age and experience and isolate maternal care as the proximate source of any differences in performance. Younger first-time mothers produced larger broods than older first-time mothers, but did not rear more offspring to independence. Across repeated reproductive events, maternal age was unassociated with any metric of performance. At later reproductive events, however, mothers produced fewer metamorphs, and a lower proportion of individuals in their broods reached independence. These patterns suggest that performance does not improve with age or breeding experience in this frog, and that eventual declines in performance are driven by reproductive activity, not age per se. Broadly, age-specific patterns of reproductive performance may depend on the proximate mechanism by which parents influence offspring fitness and how sensitive these are to effort and competence.

  17. Frog: Asynchronous Graph Processing on GPU with Hybrid Coloring Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xuanhua; Luo, Xuan; Liang, Junling; Zhao, Peng; Di, Sheng; He, Bingsheng; Jin, Hai

    2018-01-01

    GPUs have been increasingly used to accelerate graph processing for complicated computational problems regarding graph theory. Many parallel graph algorithms adopt the asynchronous computing model to accelerate the iterative convergence. Unfortunately, the consistent asynchronous computing requires locking or atomic operations, leading to significant penalties/overheads when implemented on GPUs. As such, coloring algorithm is adopted to separate the vertices with potential updating conflicts, guaranteeing the consistency/correctness of the parallel processing. Common coloring algorithms, however, may suffer from low parallelism because of a large number of colors generally required for processing a large-scale graph with billions of vertices. We propose a light-weight asynchronous processing framework called Frog with a preprocessing/hybrid coloring model. The fundamental idea is based on Pareto principle (or 80-20 rule) about coloring algorithms as we observed through masses of realworld graph coloring cases. We find that a majority of vertices (about 80%) are colored with only a few colors, such that they can be read and updated in a very high degree of parallelism without violating the sequential consistency. Accordingly, our solution separates the processing of the vertices based on the distribution of colors. In this work, we mainly answer three questions: (1) how to partition the vertices in a sparse graph with maximized parallelism, (2) how to process large-scale graphs that cannot fit into GPU memory, and (3) how to reduce the overhead of data transfers on PCIe while processing each partition. We conduct experiments on real-world data (Amazon, DBLP, YouTube, RoadNet-CA, WikiTalk and Twitter) to evaluate our approach and make comparisons with well-known non-preprocessed (such as Totem, Medusa, MapGraph and Gunrock) and preprocessed (Cusha) approaches, by testing four classical algorithms (BFS, PageRank, SSSP and CC). On all the tested applications and

  18. Standardization of an experimental model of parabiotic isolated heart in rabbits Padronização de modelo experimental de coração isolado parabiótico em coelhos

    Directory of Open Access Journals (Sweden)

    Antônio Sérgio Martins

    2000-09-01

    Full Text Available The objective was to standardize an experimental model of parabiotic isolated heart in rabbits, testing their stability and durability for use in cardiovascular research. Sixty-six Norfolk-2000 rabbits were used and divided in 2 groups: donors of the isolated heart and support animals, in a total of 33 preparations. Circulatory support for the isolated heart was established with the aid of peristaltic pumps and the flow was kept constant (16ml/min.. An intraventricular balloon was inserted in the left ventriculum, and was adjusted to produce diastolic pressure of ± 10mmHg. Heart rate was established at 120 beats per minute with the use of a pacemaker. Hemodynamic, laboratory and histopathological parameters were evaluated. Of the 33 preparations, 13 were excluded according to preestablished criteria. Of the 20 remaining preparations, 10 completed the maximum protocol time (180 minutes. There was progressive hemodynamic deterioration with decrease of mean blood pressure (89.30±6.09mmHg->47.50±6.35mmHg in the support animal. There was hemodynamic stability of the isolated heart for the 10 preparations that completed the 180 minutes of the protocol. Laboratory parameters showed progressive decrease of sodium, potassium and hemoglobin, which is compatible with hemodilution. Histopathology showed greater distance among the fibers, compatible with edema. The present model showed 100% stability and activity of the preparations within 60 minutes, and 50% of the active preparations were progressively lost within 180 minutes. The present model is viable for cardiovascular research.O objetivo foi a padronização de modelo experimental de coração isolado parabiótico em coelhos, testando sua estabilidade e durabilidade, para fins de pesquisa cardiovascular. Foram utilizados 66 coelhos raça Norfolk-2000 divididos em grupo doador do coração isolado e animais suporte, totalizando 33 preparações. Mediante auxilio de bombas peristálticas estabeleceu

  19. Sexual differences in prevalence of a new species of trypanosome infecting t?ngara frogs

    OpenAIRE

    Bernal, Ximena E.; Pinto, C. Miguel

    2016-01-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypa...

  20. The life history of Hepatozoon leptodactyli (Lesage, 1908 Pessoa, 1970: a parasite of the common laboratory animal: the frog of the genus Leptodactylus

    Directory of Open Access Journals (Sweden)

    Sylvio Celso Goncalves da Costa

    1973-01-01

    Full Text Available The main object of the present paper is to furnish a brief account to the knowledgement of Protozoa parasitic in common Brazilian frog of the genus Leptodactylus for general students in Zoology and for investigators that use this frog as a laboratory animal. Hepatozoon leptodactyli (Haemogregarina leptodactyli was found in two species of frogs - Leptodactylus ocellatus and L. pentadactylus - in which develop schizogony whereas sporogony occurs in the leech Haementeria lutzi as was obtainded in experimental conditions. Intracellular forms have been found in peripheral circulation, chiefly in erythrocytes, but we have found them in leukocytes too. Tissue stages were found in frog, liver, lungs, spleen, gut, brain and heart. The occurence of hemogregarine in the Central Nervous System was recorded by Costa & al,(13 and Ball (2. Some cytochemical methods were employed in attempt to differentiate gametocytes from trophozoites in the peripheral blood and to characterize the cystic membrane as well. The speorogonic cycle was developed in only one specie of leech. A brief description of the parasite is given.Os autores apresentam uma revisão da hemogregarina parasita de rãs do gênero Leptodactylus. A posisção sistemática sob o ponto de vista genérico fica definida com os estudos do ciclo no vetor Haementeria lutzi, publicados em nota preliminar por um dos autores (Pessoa 24 quando utilizou rãs L. petadactylus em trabalho experimental. Este trabalho experimental continua sendo desenvolvido no Laboratório de Protozoologia do Instituto Oswaldo Cruz, utilizando a rã L. ocellatus e as sanguessugas Haementeria vizuttoi e Haementeria gracilis. Algumas técnicas citoquímicas foram empregadas para melhor caracterização dos esquizontes e das granulações do citoplasma das formas sanguíneas.

  1. Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James, L.; Ulyshen, Michael D.; Kilgo, John, C.

    2005-04-01

    ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  2. Effect of cattle exclosures on Columbia Spotted Frog abundance

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher; Chambert, Thierry; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2018-01-01

    Livestock grazing is an important land use in the western USA and can have positive or negative effects on amphibians. Columbia Spotted Frog (Rana luteiventris) often use ponds that provide water for cattle. We conducted a long-term manipulative study on US Forest Service land in northeastern Oregon to determine the effects of full and partial exclosures that limited cattle access to ponds used by frogs. We found weak evidence of a short-term increase in abundance that did not differ between full and partial exclosures and that diminished with continuing exclusion of cattle. The benefit of exclosures was small relative to the overall decline in breeding numbers that we documented. This suggests that some protection can provide a short-term boost to populations.

  3. Old World frog and bird vocalizations contain prominent ultrasonic harmonics

    Science.gov (United States)

    Narins, Peter M.; Feng, Albert S.; Lin, Wenyu; Schnitzler, Hans-Ulrich; Denzinger, Annette; Suthers, Roderick A.; Xu, Chunhe

    2004-02-01

    Several groups of mammals such as bats, dolphins and whales are known to produce ultrasonic signals which are used for navigation and hunting by means of echolocation, as well as for communication. In contrast, frogs and birds produce sounds during night- and day-time hours that are audible to humans; their sounds are so pervasive that together with those of insects, they are considered the primary sounds of nature. Here we show that an Old World frog (Amolops tormotus) and an oscine songbird (Abroscopus albogularis) living near noisy streams reliably produce acoustic signals that contain prominent ultrasonic harmonics. Our findings provide the first evidence that anurans and passerines are capable of generating tonal ultrasonic call components and should stimulate the quest for additional ultrasonic species.

  4. The Genome of the Western Clawed Frog Xenopus tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, Uffe; Harland, Richard M.; Gilchrist, Michael J.; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H.; Shu, Shengqiang; Taher, Leila; Blitz, Ira L.; Blumberg, Bruce; Dichmann, Darwin S.; Dubchak, Inna; Amaya, Enrique; Detter, John C.; Fletcher, Russell; Gerhard, Daniela S.; Goodstein, David; Graves, Tina; Grigoriev, Igor V.; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M.; Mead, Paul E.; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V.; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K.; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D.; Warren, Wesley C.; Wells, Dan; Wills, Andrea; Wilson, Richard K.; Zimmerman, Lyle B.; Zorn, Aaron M.; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K.; Richardson, Paul M.; Rokhsar, Daniel S.

    2009-10-01

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes over 20,000 protein-coding genes, including orthologs of at least 1,700 human disease genes. Over a million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like other tetrapods, the genome contains gene deserts enriched for conserved non-coding elements. The genome exhibits remarkable shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  5. The rediscovered Hula painted frog is a living fossil.

    Science.gov (United States)

    Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig

    2013-01-01

    Amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. Because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. Here we report the rediscovery of the Hula painted frog, the first amphibian to have been declared extinct. We provide evidence that not only has this species survived undetected in its type locality for almost 60 years but also that it is a surviving member of an otherwise extinct genus of alytid frogs, Latonia, known only as fossils from Oligocene to Pleistocene in Europe. The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian.

  6. ESR analysis of irradiated frogs' legs and fishes

    International Nuclear Information System (INIS)

    Raffi, J.; Agnel, J.-P.; Evans, J.C.; Rowlands, C.C.; Lesgards, G.

    1989-01-01

    Electron spin resonance (ESR) spectral analysis of different parts (bones, scales, jaw, etc.) from ionized (irradiated) frozen frogs' legs and fishes (brown trout and sardine) were recorded. There is always present, after treatment, a signal due to the irradiation. ESR and ENDOR experiments lead us to assign it to h 1 centers from hydroxyapatite, as in the case of other irradiated meat bones. The use of ESR to prove whether one of these foods has been irradiated or not is discussed. (author)

  7. Vocalizations of primary forest frog species in the Central Amazon.

    OpenAIRE

    Zimmerman, Barbara L.; Bogart, James P.

    1984-01-01

    The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos National Park near Itaituba, the Reserva Ducke near Manaus, and the INPA-WWF reserves near Manaus. Structural and time parameters and sonographs of these calls including previously undescribed vocalization by 10 species are presented. Unlike open habitat species, several forest frong species characteriscally demonstrated one on more of the following temporal parameters: very low call rates, sporadic i...

  8. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    discrimination from background noise and heterospecific calls. However, we present here evidence that two anurans, Brachycephalus ephippium and B. pitanga, are insensitive to the sound of their own calls. Both species produce advertisement calls outside their hearing sensitivity range and their inner ears...... by their high toxicity might help to explain why calling has not yet disappeared, and that visual communication may have replaced auditory in these colourful, diurnal frogs....

  9. Reflex Marine celebrates 10. anniversary of FROG crew transfer device

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-07-15

    Reflex Marine developed the initial 3-person FROG crew transfer device in response to the main risks identified from incidents involving traditional rope baskets for personnel transfer: falling, collisions, hard landings, and immersion. To address these issues, the FROG was developed with 4-point harnesses, a protective shell, shock-absorbing landing feet, and self-righting capability. As a result of industry demand for a higher capacity transfer device, the company introduced 6- and 9-man versions of the FROG. The perceptions and reality of marine transfers have changed greatly over the past decade, from the design of the device to vessel specifications and increased focus on crane operations. Marine transfers offer a low-risk alternative to helicopter transfers. The TORO, a low-cost crew transfer capsule launched in February 2009, fits into a standard shipping container, providing significant logistical advantages. The TORO can carry 4 passengers, offer protection from side impacts and hard landings, and is buoyant and self-righting. Most of the units are being used by major oil and gas companies, but offshore wind turbines are an emerging source of demand for the crew transfer system. 3 figs.

  10. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

    Science.gov (United States)

    Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

  11. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Nielsen, Robert

    2000-01-01

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  12. Heart Truth

    Science.gov (United States)

    ... health! Get a free badge or banner to post to your website or blog. Are you at risk for heart disease? Here's how to find out . Planning to use The Heart Truth logo? Check out our logo guidelines and downloads. ...

  13. Heart Disease

    Science.gov (United States)

    ... it may be caused by diseases, such as connective tissue disorders, excessive iron buildup in your body (hemochromatosis), the buildup of abnormal proteins (amyloidosis) or by some cancer treatments. Causes of heart infection A heart infection, ...

  14. Heart Attack

    Science.gov (United States)

    ... family history of heart attack race – African Americans, Mexican Americans, Native Americans, and native Hawaiians are at ... Your doctor will prescribe the medicines that are right for you. If you have had a heart ...

  15. Phosphorus nuclear magnetic resonance studies of the energetic state and of the intracellular pH of the isolated rat heart in the course of ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, A [Grenoble-1 Univ., 38 (France); Martin, J; de Leiris, J [CEA Centre d' Etudes Nucleaires de Grenoble, 38 (France). Lab. de Chimie Organique Physique

    1981-01-01

    Continuous measurements of high energy phosphate compounds and intracellular pH in perfused, beating rat hearts, were performed by /sup 31/P nuclear magnetic resonance (NMR). Hearts were placed in a 15 mm NMR tube and perfused at 28/sup 0/C by conventional methods with a phosphate-free solution. Phosphorus NMR spectra were recorded at 101,3 MHz in a Brucker WP 250 spectrometer. Global mild ischemia was achieved by reducing the coronary flow to 1/10 of its initial value. Changes in creatine phosphate (CP) and inorganic phosphate (Pi) levels and intracellular pH (pHi) were monitored in the course of a 50 min ischemia and during the post-ischemic phase. When the breakdown of CP was less than 30%, the decrease in pHi was about 0.1 to 0.2 pH unit; for a greater CP decrease, the fall in pHi was about 1 pH unit.

  16. Heart pacemaker

    Science.gov (United States)

    Cardiac pacemaker implantation; Artificial pacemaker; Permanent pacemaker; Internal pacemaker; Cardiac resynchronization therapy; CRT; Biventricular pacemaker; Arrhythmia - pacemaker; Abnormal heart ...

  17. IgE antibodies of fish allergic patients cross-react with frog parvalbumin.

    Science.gov (United States)

    Hilger, C; Thill, L; Grigioni, F; Lehners, C; Falagiani, P; Ferrara, A; Romano, C; Stevens, W; Hentges, F

    2004-06-01

    The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross-recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin alpha has been found to be responsible for a case of IgE-mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross-react with frog parvalbumin and to appreciate its clinical relevance. The sera of 15 fish allergic patients and one fish and frog allergic patient were tested by IgE-immunoblotting against frog muscle extract. Sera were tested against recombinant parvalbumin alpha and beta from Rana esculenta. Skin prick tests were performed in selected patients with recombinant frog parvalbumin. Ca(2+) depletion experiments and inhibition studies with purified cod and frog recombinant parvalbumin were done to characterize the cross-reactive pattern. Fourteen of the sera tested had IgE antibodies recognizing low molecular weight components in frog muscle extract. Calcium depletion experiments or inhibition of patient sera with purified cod parvalbumin led to a significant or complete decrease in IgE binding. When tested against recombinant parvalbumins, three of 13 sera reacted with alpha parvalbumin and 11 of 12 reacted with beta parvalbumin from R. esculenta. Skin prick tests performed with recombinant frog parvalbumin were positive in fish allergic patients. Inhibition studies showed that a fish and frog allergic patient was primarily sensitized to fish parvalbumin. Cod parvalbumin, a major cross-reactive allergen among different fish species, shares IgE binding epitopes with frog parvalbumin. This in vitro cross-reactivity seems to be also clinically relevant. Parvalbumins probably represent a new family of cross-reactive allergens.

  18. An addition to the diversity of dendrobatid frogs in Venezuela: description of three new collared frogs (Anura: Dendrobatidae: Mannophryne

    Directory of Open Access Journals (Sweden)

    César Luis Barrio-Amorós

    2010-07-01

    Full Text Available Three new species of collared frogs of the genus Mannophryne are described from Venezuela. Two are newly discovered taxa from the Venezuelan Andes, whereas the third species, previously confused with M. trinitatis, is from the Caracas area in the Cordillera de la Costa. The call of the three new species and that of Mannophryne collaris are described. Taxonomic, zoogeographic, and conservation issues are discussed.

  19. Role of mitochondrial ATP-sensitive potassium channel-mediated PKC-ε in delayed protection against myocardial ischemia/reperfusion injury in isolated hearts of sevoflurane-preconditioned rats

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C. [Department of Anesthesiology and Critical Care, The Second Affiliate Hospital, Soochow University, Suzhou (China); Institute of Neuroscience, Soochow University, Suzhou (China); Hu, S.M. [Institute of Neuroscience, Soochow University, Suzhou (China); Xie, H.; Qiao, S.G. [Department of Anesthesiology and Critical Care, The Second Affiliate Hospital, Soochow University, Suzhou (China); Liu, H. [Department of Anesthesiology and Pain Medicine, University of California Davis Health System, Davis, CA (United States); Liu, C.F. [Institute of Neuroscience, Soochow University, Suzhou (China)

    2015-03-27

    This study aimed to determine the role of mitochondrial adenosine triphosphate-sensitive potassium (mitoK{sub ATP}) channels and protein kinase C (PKC)-ε in the delayed protective effects of sevoflurane preconditioning using Langendorff isolated heart perfusion models. Fifty-four isolated perfused rat hearts were randomly divided into 6 groups (n=9). The rats were exposed for 60 min to 2.5% sevoflurane (the second window of protection group, SWOP group) or 33% oxygen inhalation (I/R group) 24 h before coronary occlusion. The control group (CON) and the sevoflurane group (SEVO) group were exposed to 33% oxygen and 2.5% sevoflurane for 60 min, respectively, without coronary occlusion. The mitoK{sub ATP} channel inhibitor 5-hydroxydecanoate (5-HD) was given 30 min before sevoflurane preconditioning (5-HD+SWOP group). Cardiac function indices, infarct sizes, serum cardiac troponin I (cTnI) concentrations, and the expression levels of phosphorylated PKC-ε (p-PKC-ε) and caspase-8 were measured. Cardiac function was unchanged, p-PKC-ε expression was upregulated, caspase-8 expression was downregulated, cTnI concentrations were decreased, and the infarcts were significantly smaller (P<0.05) in the SWOP group compared with the I/R group. Cardiac function was worse, p-PKC-ε expression was downregulated, caspase-8 expression was upregulated, cTnI concentration was increased and infarcts were larger in the 5-HD+SWOP group (P<0.05) compared with the SWOP group. The results suggest that mitoK{sub ATP} channels are involved in the myocardial protective effects of sevoflurane in preconditioning against I/R injury, by regulating PKC-ε phosphorylation before ischemia, and by downregulating caspase-8 during reperfusion.

  20. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia) commercialized in France

    OpenAIRE

    Ohler, Annemarie; Nicolas, Violaine

    2017-01-01

    International audience; Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya ca...

  1. How fast do amphibians disperse? Introductions, distribution and dispersal of the common frog Rana temporaria and the common toad Bufo bufo on a coastal island in Central Norway

    Directory of Open Access Journals (Sweden)

    Dag Dolmen

    2016-04-01

    Full Text Available The common frog (Rana temporaria and the common toad (Bufo bufo were introduced successfully to the coastal island of Frøya in Central Norway several times during 1960–2012. There is still a very high degree of conformity between sites where they were introduced and the present distribution of the two species. However, in western Frøya, a release of frogs about 1996 was followed by a quick expansion of their distribution area; in 2012 and 2013, breeding was registered close to 7 km westwards and eastwards, respectively, i.e. a population dispersal speed of approximately 0.4 km/yr. On eastern Frøya and some small islands in the archipelago, area expansions at another four frog localities have been prevented by ecological barriers like unfavourable limnetic or terrestrial habitats or salty water. Two local common toad populations on eastern Frøya do not show any expansion either. However, an apparently isolated record of the species on western Frøya in 2011 can possibly be explained by the expansion westwards of a population in northern central Frøya, where toads were introduced around 1995. This stretch is about 9.9 km, i.e. an average population dispersal speed of 0.6 km/yr.

  2. Isolated congenital heart block in undifferentiated connective tissue disease and in primary Sjögren’s syndrome: a clinical study of 81 pregnancies in 41 patients

    Directory of Open Access Journals (Sweden)

    S. Todesco

    2011-09-01

    Full Text Available Objective: To study the incidence and the features of congenital heart block (CHB in patients with undifferentiated connective tissue disease (UCTD and primary Sjögren’s syndrome (pSS. Methods: We studied 81 pregnancies of 41 women attending the Outpatients’ Clinic of the Rheumatology Unit of University Hospital of Padova from July 1989 to March 2004. Twenty five of these (61% were affected with UCTD and 16 (39% with pSS. Serologic inclusion criteria was anti-Ro/La positivity, assessed by counterimmunoelectrophoresis and ELISA. Results: CHB was found in 2 out of the 46 (4,3% pregnancies followed by our Staff and in 2 out of the 35 (5,7% included in the retrospective part of the study. In 3 cases CHB was a 3rd degree block, causing pregnancy termination in 2. The only 2nd degree block was identified in one patient at the 22nd week of gestation and treated with dexamethasone and plasma-exchange. All of the women were positive to 52 kd and 60 kd Ro autoantibodies. CHB mothers had higher titer antibodies to 52 kd Ro protein than did the mothers with healthy infants (P = 0,026. Electrocardiographic abnormalities at birth were found in 3 out of 29 asymptomatic infants. One presented sinus bradycardia, the second abnormalities of ventricular repolarization, both regressed spontaneously, while the third ventricular extrasystoles which continue even now at 5 months. Conclusion: These results showed that in UCTD and pSS there is a higher incidence of CHB than that reported in Systemic Lupus Erythematosus. Electrocardiographic screening in all infants born to mothers with anti-Ro/La antibodies would seem an important measure to identify those with irreversible heart conduction abnormalities.

  3. A frog's-eye view of the landscape : quantifying connectivity for fragmented amphibian populations

    NARCIS (Netherlands)

    Vos, C.C.

    1999-01-01

    The spatial habitat requirements are studied for two amphibian species: the tree frog ( Hyla arborea ) and the moor frog ( Rana arvalis ). Fragmentation, the destruction of suitable habitat, results in small fragments that are separated by

  4. Propulsive force calculations in swimming frogs I. A momentum-impulse approach

    NARCIS (Netherlands)

    Nauwelaerts, S; Stamhuis, EJ; Aerts, P

    Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

  5. Surveys for California red-legged frog and arroyo toad on the Los Padres National Forest

    Science.gov (United States)

    Valerie K. Hubbartt; Thomas G. Murphey

    2005-01-01

    Starting in the spring of 1999 through the fall of 2000, USDA Forest Service biologists have conducted surveys throughout the Los Padres National Forest for the federally-listed California red-legged frog (Rana aurora draytonii) and arroyo toad (Bufo californicus). Sites known to have frogs or toads present were monitored for...

  6. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs.

    Science.gov (United States)

    Bernal, Ximena E; Pinto, C Miguel

    2016-04-01

    Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus), a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp.), were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

  7. Bacterial flora on Cascades frogs in the Klamath Mountains of California

    Science.gov (United States)

    Karen Pope

    2013-01-01

    Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

  8. Ichthyophonus sp. (Ichthyophonae, Ichthyophonida) infection in a South American amphibian, the hylid frog Hypsiboas pulchellus.

    Science.gov (United States)

    Borteiro, Claudio; Verdes, José Manuel; Cruz, Juan Carlos; Sabalsagaray, María Jesús; Kolenc, Francisco; Martínez Debat, Claudio; Ubilla, Martín

    2015-04-01

    We report infection by Ichthyophonus sp. in a South American amphibian, the hylid frog Hypsiboas pulchellus in Uruguay. This frog had a large subcutaneous mass over the urostyle and dorsal musculature comprised of parasitic cysts with mild granulomatous inflammation but otherwise appeared healthy.

  9. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

    Directory of Open Access Journals (Sweden)

    S D Biju

    Full Text Available Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae, this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

  10. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

    2005-01-01

    Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  11. Parasites of the mink frog (rana septentrionalis) from Minnesota, U.S.A.

    Science.gov (United States)

    Schotthoefer, Anna M.; Bolek, M.G.; Cole, Rebecca A.; Beasley, Val R.

    2009-01-01

    Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

  12. Cryptic diversity and deep divergence in an upper Amazonian leaflitter frog, Eleutherodactylus ockendeni

    Directory of Open Access Journals (Sweden)

    Dávila José A

    2007-12-01

    Full Text Available Abstract Background The forests of the upper Amazon basin harbour some of the world's highest anuran species richness, but to date we have only the sparsest understanding of the distribution of genetic diversity within and among species in this region. To quantify region-wide genealogical patterns and to test for the presence of deep intraspecific divergences that have been documented in some other neotropical anurans, we developed a molecular phylogeny of the wide-spread terrestrial leaflitter frog Eleutherodactylus ockendeni (Leptodactylidae from 13 localities throughout its range in Ecuador using data from two mitochondrial genes (16S and cyt b; 1246 base pairs. We examined the relation between divergence of mtDNA and the nuclear genome, as sampled by five species-specific microsatellite loci, to evaluate indirectly whether lineages are reproductively isolated where they co-occur. Our extensive phylogeographic survey thus assesses the spatial distribution of E. ockendeni genetic diversity across eastern Ecuador. Results We identified three distinct and well-supported clades within the Ecuadorean range of E. ockendeni: an uplands clade spanning north to south, a northeastern and central lowlands clade, and a central and southeastern clade, which is basal. Clades are separated by 12% to 15% net corrected p-distance for cytochrome b, with comparatively low sequence divergence within clades. Clades marginally overlap in some geographic areas (e.g., Napo River basin but are reproductively isolated, evidenced by diagnostic differences in microsatellite PCR amplification profiles or DNA repeat number and coalescent analyses (in MDIV best modelled without migration. Using Bayesian (BEAST and net phylogenetic estimates, the Southeastern Clade diverged from the Upland/Lowland clades in the mid-Miocene or late Oligocene. Lowland and Upland clades speciated more recently, in the early or late Miocene. Conclusion Our findings uncover previously

  13. Isolation and characterization of cAMP-free and cAMP-bound forms of bovine heart type II cAMP-dependent protein kinase

    International Nuclear Information System (INIS)

    Cobb, C.E.

    1986-01-01

    Bovine heart type II cAMP-dependent protein kinase holoenzyme (cAMP-PK) was purified to homogeneity as determined by denaturing SDS-PAGE. An HPLC-DEAE purification step resolved two distinct peaks of cAMP-dependent kinase activity, which were designated Peak 1 and Peak 2 based on their order of elution. They had the same Stoke's radii and had very similar sedimentation coefficients. As determined by densitometric scanning of SDS-PAGE brands, by their mobility on denaturing PAGE, and by the ratios of equilibrium [ 3 H] cAMP binding to maximal kinase activity, the subunit stoichiometry of the two peaks was the same. In a cAMP assay it was found that Peak 1 holoenzyme was cAMP-free, but half of the Peak 2 holoenzyme cAMP binding sites contained cAMP. Dissociation assays indicated that the cAMP was equally distributed in binding Site 1 and Site 2 of Peak 2. Although SDS-PAGE analysis ruled out conversions by proteolysis or autophosphorylation-dephosphorylation, Peak 1 could be partially converted to Peak 2 by the addition of subsaturating amounts of cAMP, and Peak 2 could be partially converted to Peak 1 by aging. The interconvertibility of the two holoenzyme peaks strongly suggested that the difference between the two peaks was caused by the presence of cAMP in Peak 2

  14. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  15. Heart regeneration.

    Science.gov (United States)

    Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

    2016-07-01

    Regenerating an injured heart holds great promise for millions of patients suffering from heart diseases. Since the human heart has very limited regenerative capacity, this is a challenging task. Numerous strategies aiming to improve heart function have been developed. In this review we focus on approaches intending to replace damaged heart muscle by new cardiomyocytes. Different strategies for the production of cardiomyocytes from human embryonic stem cells or human induced pluripotent stem cells, by direct reprogramming and induction of cardiomyocyte proliferation are discussed regarding their therapeutic potential and respective advantages and disadvantages. Furthermore, different methods for the transplantation of pluripotent stem cell-derived cardiomyocytes are described and their clinical perspectives are discussed. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Heart Failure

    OpenAIRE

    McMurray, John; Ponikowski, Piotr

    2011-01-01

    Heart failure occurs in 3% to 4% of adults aged over 65 years, usually as a consequence of coronary artery disease or hypertension, and causes breathlessness, effort intolerance, fluid retention, and increased mortality. The 5-year mortality in people with systolic heart failure ranges from 25% to 75%, often owing to sudden death following ventricular arrhythmia. Risks of cardiovascular events are increased in people with left ventricular systolic dysfunction (LVSD) or heart failure.

  17. Artificial heart

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-18

    Super-pure plutonium-238 could use heat produced during fission to power an implanted artificial heart. Three model hearts have worked for some time. Concern that excess heat would make the procedure unsafe for humans has broadened the search for another energy source, such as electrohydraulic drive or an external power battery. A back pack approach may provide an interim solution until materials are developed which can withstand heart activity and be small enough for implantation.

  18. Types of Heart Failure

    Science.gov (United States)

    ... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and procedures related to heart disease and stroke. Heart Failure Questions to Ask Your Doctor Use these questions ...

  19. Alternative leech vectors for frog and turtle trypanosomes.

    Science.gov (United States)

    Siddall, M E; Desser, S S

    1992-06-01

    Trypanosoma pipientis infections were achieved by exposing laboratory-raised bullfrog tadpoles (Rana catesbeiana) to the leech Desserobdella picta that had fed on infected frogs. Likewise, a laboratory-raised snapping turtle (Chelydra serpentina) was infected with Trypanosoma chrysemydis following exposure to infected Placobdella ornata. Transmission of the trypanosomes by these leeches constitutes new vector records for the parasites. The biology of D. picta and P. ornata suggests that they are more important in transmitting these flagellates than the species of leech previously reported as vectors.

  20. Taxonomy Icon Data: Japanese tree frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese tree frog Hyla japonica Chordata/Vertebrata/Amphibia Hyla_japonica_L.png Hyla_jap...onica_NL.png Hyla_japonica_S.png Hyla_japonica_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap...onica&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap

  1. DNA methylation abnormalities in congenital heart disease.

    Science.gov (United States)

    Serra-Juhé, Clara; Cuscó, Ivon; Homs, Aïda; Flores, Raquel; Torán, Núria; Pérez-Jurado, Luis A

    2015-01-01

    Congenital heart defects represent the most common malformation at birth, occurring also in ∼50% of individuals with Down syndrome. Congenital heart defects are thought to have multifactorial etiology, but the main causes are largely unknown. We have explored the global methylation profile of fetal heart DNA in comparison to blood DNA from control subjects: an absolute correlation with the type of tissue was detected. Pathway analysis revealed a significant enrichment of differential methylation at genes related to muscle contraction and cardiomyopathies in the developing heart DNA. We have also searched for abnormal methylation profiles on developing heart-tissue DNA of syndromic and non-syndromic congenital heart defects. On average, 3 regions with aberrant methylation were detected per sample and 18 regions were found differentially methylated between groups. Several epimutations were detected in candidate genes involved in growth regulation, apoptosis and folate pathway. A likely pathogenic hypermethylation of several intragenic sites at the MSX1 gene, involved in outflow tract morphogenesis, was found in a fetus with isolated heart malformation. In addition, hypermethylation of the GATA4 gene was present in fetuses with Down syndrome with or without congenital heart defects, as well as in fetuses with isolated heart malformations. Expression deregulation of the abnormally methylated genes was detected. Our data indicate that epigenetic alterations of relevant genes are present in developing heart DNA in fetuses with both isolated and syndromic heart malformations. These epimutations likely contribute to the pathogenesis of the malformation by cis-acting effects on gene expression.

  2. Comparative study of tranavirus isolates from cod (Gadus morhua) and turbot (Psetta maxima) with reference to other ranaviruses

    DEFF Research Database (Denmark)

    Ariel, Ellen; Holopainen, Riikka; Olesen, Niels Jørgen

    2010-01-01

    Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity in immun......Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity......). The challenge trials indicate that rainbow trout fry cultured at 15A degrees C are not target species for the virus isolates in the present panel. We suggest that the two isolates belong in the genus Ranavirus and propose the name Ranavirus maxima (Rmax) for the turbot isolate....

  3. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium.

    Science.gov (United States)

    Arcanjo, Daniel Dias Rufino; Vasconcelos, Andreanne Gomes; Comerma-Steffensen, Simón Gabriel; Jesus, Joilson Ramos; Silva, Luciano Paulino; Pires Júnior, Osmindo Rodrigues; Costa-Neto, Claudio Miguel; Oliveira, Eduardo Brandt; Migliolo, Ludovico; Franco, Octávio Luiz; Restini, Carolina Baraldi Araújo; Paulo, Michele; Bendhack, Lusiane Maria; Bemquerer, Marcelo Porto; Oliveira, Aldeidia Pereira; Simonsen, Ulf; Leite, José Roberto de Souza de Almeida

    2015-01-01

    Proline-rich oligopeptides (PROs) are a large family which comprises the bradykinin-potentiating peptides (BPPs). They inhibit the activity of the angiotensin I-converting enzyme (ACE) and have a typical pyroglutamyl (Pyr)/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO). Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.

  4. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium.

    Directory of Open Access Journals (Sweden)

    Daniel Dias Rufino Arcanjo

    Full Text Available Proline-rich oligopeptides (PROs are a large family which comprises the bradykinin-potentiating peptides (BPPs. They inhibit the activity of the angiotensin I-converting enzyme (ACE and have a typical pyroglutamyl (Pyr/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO. Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.

  5. Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Samantha Vertucci

    Full Text Available Southwest Australia (SWA is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals, and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly

  6. Efeitos da N-acetilcisteína no precondicionamento isquêmico: estudo em corações isolados de ratos Effects of n-acetylcysteine on ischemic preconditioning: study in isolated rat hearts

    Directory of Open Access Journals (Sweden)

    Denoel Marcelino de Oliveira

    2009-03-01

    Full Text Available OBJETIVO: Avaliar se a N-Acetilcisteína (NAC altera o Precondicionamento Isquêmico (PC em corações isolados de ratos usando apenas um ciclo de PC. MÉTODOS: Freqüência Cardíaca (FC, Fluxo Coronariano (FLC e Contratilidade Miocárdica (dP/dt foram registradas em 30 corações de ratos Wistar. Após anestesia, os corações foram perfundidos em sistema de Langendorff com solução de Krebs-Hensleit (K-H, equilibrada (95% de O2 e 5% de CO2. GI: Controle (n=6; GII: 20 min. isquemia (n=6; GIII: PC (n=6; GIV 50 µg/ml/min NAC antes do PC (n =6; GV: 100 µg/ml/min NAC antes do PC (n=6. Todos os parâmetros foram mensurados após 15 minutos de estabilização (T0 e T3, T5, T10, T15, T20, T25 e T30 minutos de reperfusão. Significância estatística foi considerada quando P0,05. dP/dt foi maior no GV comparado com GIV, mas com diferença estatisticamente significativa somente em T30. CONCLUSÃO: Os corações precondicionados tiveram melhor dP/dt, sendo alteradas pelo uso de NAC no GIV e não alteradas no GV.OBJECTIVE: The aim of this study is to assess if N-Acetylcysteine (NAC changes the Ischemic Preconditioning (IP in isolated rat hearts using only one cycle of IP. METHODS: Heart Rate (HR, Coronary Flow (CF and Myocardial Contractility (dP/dt were registered in 30 Wistar rat's hearts. After anesthesia the hearts were removed and perfused with Krebes-Hensleit equilibrated solution with 95% of O2 and 5% of CO2 according Langendorff's method. GI: Control (n=6; GII: 20 min. ischemia (n=6; GIII: IP (n=6; GIV 50 µg/ml/min NAC before IP (n =6; GV: 100 µg/ ml/min NAC before IP (n=6. Parameters were measured after 15 min. of stabilization (T 0 and T3, T5, T10, T15, T20, T25 and T30 min. after reperfusion. Statistical significance was considered when P0.05. dP/dt was higher in GV than GIV but with statistically significant difference only at T30. CONCLUSION: dP/dt was better in preconditioned hearts and was changed if using NAC in GIV. The use of NAC

  7. A Method for Mechanism Analysis of Frog Swimming Based on Motion Observation Experiments

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2014-05-01

    Full Text Available For understanding the mechanism of frog swimming under water and designing a frog-inspired swimming robot, kinematics of the frog body and trajectories of joints should be obtained. In this paper, an aquatic frog, Xenopus laevis, was chosen for analysis of swimming motions which were recorded by a high speed camera, and kinematic data were processed in a swimming data extraction platform. According to the shape features of the frog, we propose a method that the frog eyes are set as the natural data extraction markers for body motion, and kinematic data of joint trajectories are calculated by the contour points on the limbs. For the data processing, a pinhole camera model was built to transform the pixel coordinate system to world coordinate system, and the errors caused by the water refraction were analyzed and corrected. Finally, from the developed data extraction platform, the kinematic data for the analysis of swimming mechanism and design of frog-inspired robot were obtained.

  8. Poison frog colors are honest signals of toxicity, particularly for bird predators.

    Science.gov (United States)

    Maan, Martine E; Cummings, Molly E

    2012-01-01

    Antipredator defenses and warning signals typically evolve in concert. However, the extensive variation across taxa in both these components of predator deterrence and the relationship between them are poorly understood. Here we test whether there is a predictive relationship between visual conspicuousness and toxicity levels across 10 populations of the color-polymorphic strawberry poison frog, Dendrobates pumilio. Using a mouse-based toxicity assay, we find extreme variation in toxicity between frog populations. This variation is significantly positively correlated with frog coloration brightness, a viewer-independent measure of visual conspicuousness (i.e., total reflectance flux). We also examine conspicuousness from the view of three potential predator taxa, as well as conspecific frogs, using taxon-specific visual detection models and three natural background substrates. We find very strong positive relationships between frog toxicity and conspicuousness for bird-specific perceptual models. Weaker but still positive correlations are found for crab and D. pumilio conspecific visual perception, while frog coloration as viewed by snakes is not related to toxicity. These results suggest that poison frog colors can be honest signals of prey unpalatability to predators and that birds in particular may exert selection on aposematic signal design. © 2011 by The University of Chicago.

  9. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834

    Directory of Open Access Journals (Sweden)

    Achariya Sailasuta

    2011-01-01

    Full Text Available One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834, were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140 were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia.

  10. Environmental and Host Effects on Skin Bacterial Community Composition in Panamanian Frogs

    Directory of Open Access Journals (Sweden)

    Brandon J. Varela

    2018-02-01

    Full Text Available Research on the amphibian skin microbiota has focused on identifying bacterial taxa that deter a pathogenic chytrid fungus, and on describing patterns of microbiota variation. However, it remains unclear how environmental variation affects amphibian skin bacterial communities, and whether the overall functional diversity of the amphibian skin microbiota is associated to such variation. We sampled skin microbial communities from one dendrobatoid frog species across an environmental gradient along the Panama Canal, and from three dendrobatoid frog species before and after the onset of the wet season in one site. We found frog skin microbial alpha diversity to be highest in frogs from sites with low soil pH, but no clear effect of the onset of the wet season. However, we found frog skin microbial community structure to be affected by soil pH and the onset of the wet season, which also resulted in a decrease in between-sample variation. Across the sampled frog species, bacterial functional groups changed with the onset of the wet season, with certain bacterial functional groups entirely disappearing and others differing in their relative abundances. In particular, we found the proportion of Bd-inhibitory bacteria to correlate with mean soil pH, and to increase in two of the frog species with the onset of the wet season. Taken together, our results suggest that structure and predicted function of amphibian bacterial skin communities may be influenced by environmental variables such as pH and precipitation, site effects, and host effects.

  11. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834)

    Science.gov (United States)

    Sailasuta, Achariya; Satetasit, Jetjun; Chutmongkonkul, Malinee

    2011-01-01

    One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834), were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140) were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs) surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia. PMID:21918731

  12. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    Tobias, Martha L.; Evans, Ben J.; Kelley, Darcy B.

    2014-01-01

    Summary For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types — click, burst and trill — that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  13. Network thermodynamic approach compartmental analysis. Na+ transients in frog skin.

    Science.gov (United States)

    Mikulecky, D C; Huf, E G; Thomas, S R

    1979-01-01

    We introduce a general network thermodynamic method for compartmental analysis which uses a compartmental model of sodium flows through frog skin as an illustrative example (Huf and Howell, 1974a). We use network thermodynamics (Mikulecky et al., 1977b) to formulate the problem, and a circuit simulation program (ASTEC 2, SPICE2, or PCAP) for computation. In this way, the compartment concentrations and net fluxes between compartments are readily obtained for a set of experimental conditions involving a square-wave pulse of labeled sodium at the outer surface of the skin. Qualitative features of the influx at the outer surface correlate very well with those observed for the short circuit current under another similar set of conditions by Morel and LeBlanc (1975). In related work, the compartmental model is used as a basis for simulation of the short circuit current and sodium flows simultaneously using a two-port network (Mikulecky et al., 1977a, and Mikulecky et al., A network thermodynamic model for short circuit current transients in frog skin. Manuscript in preparation; Gary-Bobo et al., 1978). The network approach lends itself to computation of classic compartmental problems in a simple manner using circuit simulation programs (Chua and Lin, 1975), and it further extends the compartmental models to more complicated situations involving coupled flows and non-linearities such as concentration dependencies, chemical reaction kinetics, etc.

  14. LOCALIZATION OF PERMEABILITY BARRIERS IN THE FROG SKIN EPITHELIUM

    Science.gov (United States)

    Martinez-Palomo, A.; Erlij, D.; Bracho, H.

    1971-01-01

    Ruthenium red and colloidal lanthanum were used to determine the site of the structural barriers to diffusion within the intercellular spaces of frog skin epithelium. Electron micrographs show that occluding zonules located at the outer border of the stratum corneum and at the outer layer of the stratum granulosum are true tight junctions since they are impermeable to these tracers. Measurement of 140La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum. Examination of these skins with the electron microscope suggests that the compartment is localized between the external membrane of the cells at the outer layer of the s. granulosum and at the outermost surface of the skin. These observations and other findings described in the literature indicate that the site of the external high resistance barrier of the frog skin is localized at the outer border of the s. granulosum. PMID:4329611

  15. A novel 35 kDa frog liver acid metallophosphatase.

    Science.gov (United States)

    Szalewicz, A; Radomska, B; Strzelczyk, B; Kubicz, A

    1999-04-12

    The lower molecular weight (35 kDa) acid phosphatase from the frog (Rana esculenta) liver is a glycometalloenzyme susceptible to activation by reducing agents and displaying tartrate and fluoride resistance. Metal chelators (EDTA, 1,10-phenanthroline) inactivate the enzyme reversibly in a time- and temperature-dependent manner. The apoenzyme is reactivated by divalent transition metal cations, i. e. cobalt, zinc, ferrous, manganese, cadmium and nickel to 130%, 75%, 63%, 62%, 55% and 34% of the original activity, respectively. Magnesium, calcium, cupric and ferric ions were shown to be ineffective in this process. Metal analysis by the emission spectrometry method (inductively coupled plasma-atomic emission spectrometry) revealed the presence of zinc, iron and magnesium. The time course of the apoenzyme reactivation, the stabilization effect and the relatively high resistance to oxidizing conditions indicate that the zinc ion is crucial for the enzyme activity. The presence of iron was additionally confirmed by the visible absorption spectrum of the enzyme with a shoulder at 417 nm and by the electron paramagnetic resonance line of high spin iron(III) with geff of 2.4. The active center containing only zinc or both zinc and iron ions is proposed. The frog liver lower molecular weight acid phosphatase is a novel metallophosphatase of lower vertebrate origin, distinct from the mammalian tartrate-resistant, purple acid phosphatases.

  16. Multiple sexual signals: Calls over colors for mate attraction in an aposematic, color-diverse poison frog

    Directory of Open Access Journals (Sweden)

    Corinna Eva Dreher

    2014-06-01

    Full Text Available Sexual signals indicate species identity and mate quality, and their importance for mate attraction is largely recognized. Recently, research in animal communication has started to integrate multiple signal modalities and evaluate their interactions. However, mate choice experiments across animal taxa have been limited to laboratory conditions, and assessments of multiple sexual signals under field conditions are still lacking. We take advantage of the divergence in visual and acoustic signals among populations of the Neotropical poison frog Oophaga pumilio to evaluate the importance of male advertisement calls and color patterns in female mate selection. Previous mate choice experiments in this species suggested color-assortative female mate preferences across many populations. Nevertheless, acoustic signals are crucial for sexual selection in frogs, and males of O. pumilio use advertisement calls to attract females. We hypothesize that both advertisement calls and coloration affects female mate selection in O.pumilio. To test this hypothesis we tested 452 receptive females from six populations in Costa Rica and Panama in their natural home ranges for preferences regarding local vs. non-local advertisement calls and color patterns. Overall, the calls overrode the effect of coloration, whereby most females preferred local over non-local calls. We found a tendency to prefer brighter (but not necessarily local males in two populations. Furthermore the strength of preferences varied geographically, and thus might be involved in prezygotic isolation among populations. The stronger effect of calls on mate attraction is associated with acoustic divergence between genetic groups in the species, while colour pattern diversity is mostly located within one genetic group, i.e. not linked to large-scale population structure. Finally our data highlights the importance to consider an array of signal modalities in multiple wild populations in studies of

  17. Influence of CO2 on electrophysiology and ionic permeability of the basolateral membrane of frog skin

    International Nuclear Information System (INIS)

    Stoddard, J.S.

    1984-01-01

    When short-circuited epithelia of frog skin bathed in an alkaline Ringer solution equilibrated with room air, are exposed to a Ringer solution equilibrated with 5% CO 2 , inhibition of transepithelial Na + transport is observed accompanied by a marked depolarization of the basolateral membrane voltage as measured with intracellular microelectrodes. To study further the mechanisms involved, basolateral membrane influxes and effluxes of 24 Na, 42 K, and 36 Cl were measured in control and CO 2 -treated isolated epithelia. In control epithelia, studies of the bidirectional 24 Na fluxes confirmed the existence of an important basolateral membrane permeability to Na + . In control epithelia, the apical membranes of the cells were found to be virtually impermeable to Cl - , while basolateral membranes were highly permeable to Cl - . Although CO 2 caused a partial inhibition of pump activity as assessed from decreases of pump-mediated Na + efflux and K + influx, CO 2 caused little or no change of the leak influx of Na + or K + . K + efflux was increased markedly with CO 2 resulting in a net loss of K + from the cells. Cl - influx was increased and Cl - efflux was decreased by CO 2 leading to a net influx of Cl - . Analysis of the data according to criteria involving changes of flux, ionic equilibrium potentials, mass and charge balance restrictions indicated that the principle changes involve a transient decrease in electrical conductance to K + with a concurrent increase in electrical conductance to HCO 3 - (OH - or H + ) of the basolateral membranes of the cells

  18. Comprehensive Transcriptome Profiling and Functional Analysis of the Frog (Bombina maxima) Immune System

    Science.gov (United States)

    Zhao, Feng; Yan, Chao; Wang, Xuan; Yang, Yang; Wang, Guangyin; Lee, Wenhui; Xiang, Yang; Zhang, Yun

    2014-01-01

    Amphibians occupy a key phylogenetic position in vertebrates and evolution of the immune system. But, the resources of its transcriptome or genome are still little now. Bombina maxima possess strong ability to survival in very harsh environment with a more mature immune system. We obtained a comprehensive transcriptome by RNA-sequencing technology. 14.3% of transcripts were identified to be skin-specific genes, most of which were not isolated from skin secretion in previous works or novel non-coding RNAs. 27.9% of transcripts were mapped into 242 predicted KEGG pathways and 6.16% of transcripts related to human disease and cancer. Of 39 448 transcripts with the coding sequence, at least 1501 transcripts (570 genes) related to the immune system process. The molecules of immune signalling pathway were almost presented, several transcripts with high expression in skin and stomach. Experiments showed that lipopolysaccharide or bacteria challenge stimulated pro-inflammatory cytokine production and activation of pro-inflammatory caspase-1. These frog's data can remarkably expand the existing genome or transcriptome resources of amphibians, especially immunity data. The entity of the data provides a valuable platform for further investigation on more detailed immune response in B. maxima and a comparative study with other amphibians. PMID:23942912

  19. Slow and fast fatigable frog muscle fibres: electrophysiological and histochemical characteristics.

    Science.gov (United States)

    Vydevska-Chichova, M; Mileva, K; Todorova, R; Dimitrova, M; Radicheva, N

    2005-12-01

    Continuous activity of isolated frog gastrocnemius muscle fibres provoked by repetitive stimulation of 5 Hz was used as an experimental model for fatigue development in different fibre types. Parameter changes of the elicited intracellular action potentials and mechanical twitches during the period of uninterrupted activity were used as criteria for fatigue evaluation. Slow fatigable muscle fibre (SMF) and fast fatigable muscle fibre (FMF) types were distinguished depending on the duration of their uninterrupted activity, which was significantly longer in SMFs than in FMFs. The normalized changes of action potential amplitude and duration were significantly smaller in FMFs than in SMFs. The average twitch force and velocity of contraction and relaxation were significantly higher in FMFs than in SMFs. Myosin ATPase (mATPase) and succinate dehydrogenase activity were studied by histochemical assessment in order to validate the fibre type classification based on their electrophysiological characteristics. Based on the relative mATPase reactivity, the fibres of the studied muscle were classified as one of five different types (1-2, 2, 2-3, 3 and tonic). Smaller sized fibres (tonic and type 3) expressed higher succinate dehydrogenase activity than larger sized fibres (type 1-2, 2), which is related to the fatigue resistance. The differences between fatigue development in SMFs and FMFs during continuous activity were associated with fibre-type specific mATPase and succinate dehydrogenase activity.

  20. Evaluating mechanisms of diversification in a Guineo-Congolian tropical forest frog using demographic model selection.

    Science.gov (United States)

    Portik, Daniel M; Leaché, Adam D; Rivera, Danielle; Barej, Michael F; Burger, Marius; Hirschfeld, Mareike; Rödel, Mark-Oliver; Blackburn, David C; Fujita, Matthew K

    2017-10-01

    The accumulation of biodiversity in tropical forests can occur through multiple allopatric and parapatric models of diversification, including forest refugia, riverine barriers and ecological gradients. Considerable debate surrounds the major diversification process, particularly in the West African Lower Guinea forests, which contain a complex geographic arrangement of topographic features and historical refugia. We used genomic data to investigate alternative mechanisms of diversification in the Gaboon forest frog, Scotobleps gabonicus, by first identifying population structure and then performing demographic model selection and spatially explicit analyses. We found that a majority of population divergences are best explained by allopatric models consistent with the forest refugia hypothesis and involve divergence in isolation with subsequent expansion and gene flow. These population divergences occurred simultaneously and conform to predictions based on climatically stable regions inferred through ecological niche modelling. Although forest refugia played a prominent role in the intraspecific diversification of S. gabonicus, we also find evidence for potential interactions between landscape features and historical refugia, including major rivers and elevational barriers such as the Cameroonian Volcanic Line. We outline the advantages of using genomewide variation in a model-testing framework to distinguish between alternative allopatric hypotheses, and the pitfalls of limited geographic and molecular sampling. Although phylogeographic patterns are often species-specific and related to life-history traits, additional comparative studies incorporating genomic data are necessary for separating shared historical processes from idiosyncratic responses to environmental, climatic and geological influences on diversification. © 2017 John Wiley & Sons Ltd.

  1. Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia

    Directory of Open Access Journals (Sweden)

    Leandro Talione Sabagh

    2012-02-01

    Full Text Available We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae and Leptodactylus andreae (Leptodactylidae in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.

  2. First report of Hepatozoon sp. in the Oregon spotted frog, Rana pretiosa.

    Science.gov (United States)

    Stenberg, Patricia L; Bowerman, William J

    2010-07-01

    From 2005 through 2008, we screened 650 Oregon spotted frogs (Rana pretiosa) from three populations in central Oregon, USA, for hemoparasites. A Hepatozoon sp., not previously reported in R. pretiosa, was found in one population of frogs, mostly as intracellular gamonts at a prevalence of 10.5% with parasitemias ranging from 0.02% to greater than 42% of erythrocytes within individual frogs. Intra-and extracellular merozoites were present, but rare. A potential vector, the mosquito Culex boharti, was common throughout the habitat of the population carrying Hepatozoon sp.

  3. Antioxidant response and metal accumulation in tissues of Iberian green frogs (Pelophylax perezi) inhabiting a deactivated uranium mine.

    Science.gov (United States)

    Marques, Sérgio M; Antunes, Sara C; Nunes, Bruno; Gonçalves, Fernando; Pereira, Ruth

    2011-08-01

    Human mining activities tend often to generate greatly impacted areas which remain contaminated for long periods of time, giving rise to extreme habitats. Mining sites are usually characterized for the production of metal rich effluents with very low pH. In this work we analyzed physical and chemical parameters of water from a deactivated uranium mine pond (M) and a reference site (REF) as well as their metal content. Furthermore, we determined and compared metal accumulation in liver, kidney, bones, muscle and skin of Pelophylax perezi from REF with P. perezi from M. We also determined the enzymatic activities of glutathione-S-transferases (GSTs), catalase (CAT), glutathione reductase (Gred), and glutathione peroxidase (GPx; both selenium-dependent and selenium-independent) in liver, kidney, lung and heart. Additionally, lipoperoxidation (LPO) was also assessed in the same tissues via thiobarbituric acid reactive substances (TBARS) assay and lactate dehydrogenase (LDH) activity was determined in muscle. Our results revealed that the majority of metals were in higher concentrations in tissues of organisms from M. This trend was especially evident for U whose content reached a difference of 1350 fold between REF and M organisms. None of the organs tested for antioxidant defenses revealed LPO, nonetheless, with exception for liver, all organs from the M frogs presented increased total GPx activity and selenium-dependent GPx. However, this response was significant only for the lung, probably as a consequence of the significant inhibition of CAT upstream and to cope with the subsequent increase in H(2)O(2). Lungs were the organs displaying greater responsiveness of the anti-oxidant stress system in frogs from the uranium mine area.

  4. Simple, heart-smart substitutions

    Science.gov (United States)

    Coronary artery disease - heart smart substitutions; Atherosclerosis - heart smart substitutions; Cholesterol - heart smart substitutions; Coronary heart disease - heart smart substitutions; Healthy diet - heart ...

  5. Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide-ranging frog species in an arid landscape.

    Science.gov (United States)

    Pilliod, David S; Arkle, Robert S; Robertson, Jeanne M; Murphy, Melanie A; Funk, W Chris

    2015-09-01

    Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900-1930), recent (1981-2010), and future (2071-2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates. We then modeled changes in surface water availability at each time period. Finally, we quantified connectivity among existing populations on the basis of hydrology and correlated it with interpopulation genetic distance. We found that the area of the Great Basin with suitable climate conditions has declined by approximately 49% over the last century and will likely continue to decline under future climate scenarios. Climate conditions at currently occupied locations have been relatively stable over the last century, which may explain persistence at these sites. However, future climates at these currently occupied locations are predicted to become warmer throughout the year and drier during the frog's activity period (May - September). Fall and winter precipitation may increase, but as rain instead of snow. Earlier runoff and lower summer base flows may reduce connectivity between neighboring populations, which is already limited. Many of these changes could have negative effects on remaining populations over the next 50-80 years, but milder winters, longer growing seasons, and wetter falls might positively affect survival and dispersal. Collectively, however, seasonal shifts in temperature, precipitation, and stream flow patterns could reduce habitat suitability and connectivity for frogs and possibly other aquatic species inhabiting streams in this arid region.

  6. Effects of changing climate on aquatic habitat and connectivity for remnant populations of a wide-ranging frog species in an arid landscape

    Science.gov (United States)

    Pilliod, David S.; Arkle, Robert S.; Robertson, Jeanne M; Murphy, Melanie; Funk, W. Chris

    2015-01-01

    Amphibian species persisting in isolated streams and wetlands in desert environments can be susceptible to low connectivity, genetic isolation, and climate changes. We evaluated the past (1900–1930), recent (1981–2010), and future (2071–2100) climate suitability of the arid Great Basin (USA) for the Columbia spotted frog (Rana luteiventris) and assessed whether changes in surface water may affect connectivity for remaining populations. We developed a predictive model of current climate suitability and used it to predict the historic and future distribution of suitable climates. We then modeled changes in surface water availability at each time period. Finally, we quantified connectivity among existing populations on the basis of hydrology and correlated it with interpopulation genetic distance. We found that the area of the Great Basin with suitable climate conditions has declined by approximately 49% over the last century and will likely continue to decline under future climate scenarios. Climate conditions at currently occupied locations have been relatively stable over the last century, which may explain persistence at these sites. However, future climates at these currently occupied locations are predicted to become warmer throughout the year and drier during the frog's activity period (May – September). Fall and winter precipitation may increase, but as rain instead of snow. Earlier runoff and lower summer base flows may reduce connectivity between neighboring populations, which is already limited. Many of these changes could have negative effects on remaining populations over the next 50–80 years, but milder winters, longer growing seasons, and wetter falls might positively affect survival and dispersal. Collectively, however, seasonal shifts in temperature, precipitation, and stream flow patterns could reduce habitat suitability and connectivity for frogs and possibly other aquatic species inhabiting streams in this arid region.

  7. The extraordinary biology and development of marsupial frogs (Hemiphractidae) in comparison with fish, mammals, birds, amphibians and other animals.

    Science.gov (United States)

    Del Pino, Eugenia M

    2018-01-03

    The study of oogenesis and early development of frogs belonging to the family Hemiphractidae provide important comparison to the aquatic development of other frogs, such as Xenopus laevis, because reproduction on land characterizes the Hemiphractidae. In this review, the multinucleated oogenesis of the marsupial frog Flectonotus pygmaeus (Hemiphractidae) is analyzed and interpreted. In addition, the adaptations associated with the incubation of embryos in the pouch of the female marsupial frog Gastrotheca riobambae (Hemiphractidae) and the embryonic development of this frog are summarized. Moreover, G. riobambae gastrulation is compared with the gastrulation modes of Engystomops randi and Engystomops coloradorum (Leptodactylidae); Ceratophrys stolzmanni (Ceratophryidae); Hyalinobatrachium fleischmanni and Espadarana callistomma (Centrolenidae); Ameerega bilinguis, Dendrobates auratus, Epipedobates anthonyi, Epipedobates machalilla, Epipedobates tricolor, and Hyloxalus vertebralis (Dendrobatidae); Eleutherodactylus coqui (Terrarana: Eleutherodactylidae), and X. laevis (Pipidae). The comparison indicated two modes of frog gastrulation. In X. laevis and in frogs with aquatic reproduction, convergent extension begins during gastrulation. In contrast, convergent extension occurs in the post-gastrula of frogs with terrestrial reproduction. These two modes of gastrulation resemble the transitions toward meroblastic cleavage found in ray-finned fishes (Actinopterygii). In spite of this difference, the genes that guide early development seem to be highly conserved in frogs. I conclude that the shift of convergent extension to the post-gastrula accompanied the diversification of frog egg size and terrestrial reproductive modes. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. The Effects of Cisplatin and Its PT(II Analogue on Oxidative Stress of Isolated Rat Heart/ Efekti Cisplatine I PT(II Analoga Cisplatine Na Oksidacioni Stres Izolovanog Srca Pacova

    Directory of Open Access Journals (Sweden)

    Stojic Isidora

    2016-03-01

    Full Text Available To date, numerous platinum (II complexes have been successfully used in the treatment of different types of cancer. Therapeutic platinum complexes are different in terms of their structure, chemical reactivity, solubility, pharmacokinetics and toxicity. The aim of our research was the evaluation of cardiotoxicity of dichloro-(ethylendiamine platinum (II in a model of isolated rat heart using the Langedorff technique. Oxidative stress was assessed by determination of superoxide anion radical, hydrogen peroxide, Thiobarbituric Acid Reactive Substances and nitric oxide levels from coronary venous effluent. All reagents were perfused at increasing concentrations from 10-8 to 10-4 M for 30 minutes. In this paper, we report that substances administered at higher doses did not induce dose-dependent effects on oxidative stress markers. The results of this research may be of great interest for future studies in this area. There are many novel platinum compounds that had previously demonstrated antitumour activity, and these types of experiments in our study can assist in the examination of their cardiotoxicity. These results could be helpful for understanding dose-dependent side effects of existing and novel platinum compounds

  9. Regulation of the insulin-Akt signaling pathway and glycolysis during dehydration stress in the African clawed frog Xenopus laevis.

    Science.gov (United States)

    Wu, Cheng-Wei; Tessier, Shannon N; Storey, Kenneth B

    2017-12-01

    Estivation is an adaptive stress response utilized by some amphibians during periods of drought in the summer season. In this study, we examine the regulation of the insulin signaling cascade and glycolysis pathway in the African clawed frog Xenopus laevis during the dehydration stress induced state of estivation. We show that in the brain and heart of X. laevis, dehydration reduces the phosphorylation of the insulin growth factor-1 receptor (IGF-1R), and this is followed by similar reductions in the phosphorylation of the Akt and mechanistic target of rapamycin (mTOR) kinase. Interestingly, phosphorylation levels of IGF-1R and mTOR were not affected in the kidney, and phosphorylation levels of P70S6K and the ribosomal S6 protein were elevated during dehydration stress. Animals under estivation are also susceptible to periods of hypoxia, suggesting that glycolysis may also be affected. We observed that protein levels of many glycolytic enzymes remained unchanged during dehydration; however, the hypoxia response factor-1 alpha (HIF-1α) protein was elevated by greater than twofold in the heart during dehydration. Overall, we provide evidence that shows that the insulin signaling pathway in X. laevis is regulated in a tissue-specific manner during dehydration stress and suggests an important role for this signaling cascade in mediating the estivation response.

  10. Heart Failure

    Science.gov (United States)

    ... Other diseases. Chronic diseases — such as diabetes, HIV, hyperthyroidism, hypothyroidism, or a buildup of iron (hemochromatosis) or ... transplantation or support with a ventricular assist device. Prevention The key to preventing heart failure is to ...

  11. Heart Attack

    Science.gov (United States)

    ... properly causes your body's blood sugar levels to rise, increasing your risk of heart attack. Metabolic syndrome. This occurs when you have obesity, high blood pressure and high blood sugar. Having metabolic ...

  12. Species Profile: Gopher Frog (Rana capito spp.) on Military Installations in the Southeastern United States

    National Research Council Canada - National Science Library

    Palis, John

    1997-01-01

    ....' Gopher frogs inhabit xeric upland pine communities of the Southeastern Coastal Plain from the southern half of the North Carolina coastal plain to southern Florida and westward to eastern Louisiana...

  13. Semaphoring in an earless frog: the origin of a novel visual signal.

    Science.gov (United States)

    Lindquist, E D; Hetherington, T E

    1998-10-01

    Social communication in anuran amphibians (frogs and toads) is mediated predominantly by acoustic signals. Unlike most anurans, the Panamanian golden frog, Atelopus zeteki, lacks a standard tympanic middle ear and appears to have augmented its communicatory repertoire to include rotational limb motions as visual signals, referred to here as semaphores. The communicatory nature of semaphoring was inferred from experimental manipulations using mirrored self-image presentations and nonresident introductions. Male frogs semaphored significantly more when presented with a mirrored self-image than with a nonreflective control. Novel encounters between resident males and nonresident frogs demonstrated that semaphores were used directionally and were displayed toward target individuals. Females semaphored frequently and this observation represents a rare case of signaling by females in a typically male-biased communicatory regime. Semaphore actions were clearly linked to a locomotory gait pattern and appear to have originated as an elaboration of a standard stepping motion.

  14. Further Development and Validation of the Frog Embryo Teratogenesis Assay - Xenopus (FETAX). Phase III

    National Research Council Canada - National Science Library

    Bantle, John

    1996-01-01

    This interlaboratory study of the Frog Embryo Teratogenesis Assay (FETAX) was undertaken in order to assess the repeatability and reliability of data collected under the guide published by the American Society for Testing and Materials...

  15. Design and Evaluation of a Digital Flight Control System for the FROG Unmanned Aerial Vehicle

    National Research Council Canada - National Science Library

    Flood, Christopher

    2001-01-01

    .... This autopilot imposed significant limitations on the responsiveness of the FROG. This project developed and tested an off board digital flight control system for use in lieu of the previous electromechanical device...

  16. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (/sup 3/H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (/sup 3/H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (/sup 3/H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand.

  17. PHENOBARBITAL AFFECTS THYROID HISTOLOGY AND LARVAL DEVELOPMENT IN THE AFRICAN CLAWED FROG XENOPUS LAEVIS

    Science.gov (United States)

    The abstract highlights our recent study to explore endocrine disrupting effects of phenobarbital in the African clawed frog, Xenopus laevis. In mammals, this chemical is known to induce the biotransforming enzyme UDP-glucuronosyltransferase (UDPGT) resulting in increased thyroid...

  18. Classes of Heart Failure

    Science.gov (United States)

    ... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and Advanced HF • Tools and Resources • Personal Stories Heart Failure Questions to Ask Your Doctor Use these questions ...

  19. Men and Heart Disease

    Science.gov (United States)

    ... Pressure Salt Cholesterol Million Hearts® WISEWOMAN Men and Heart Disease Fact Sheet Recommend on Facebook Tweet Share Compartir Source: Interactive Atlas of Heart Disease and Stroke Heart Disease Facts in Men Heart disease is the leading ...

  20. Wine and heart health

    Science.gov (United States)

    Health and wine; Wine and heart disease; Preventing heart disease - wine; Preventing heart disease - alcohol ... more often just to lower your risk of heart disease. Heavier drinking can harm the heart and ...

  1. Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

    Science.gov (United States)

    Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

    2011-04-15

    Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

    Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

  3. Effects of X-irradiation on some aspects of protein metabolism in the frog, Rana hexadactyla

    International Nuclear Information System (INIS)

    Rajarami Reddy, G.; Sasira Babu, K.

    1980-01-01

    Changes in the level of total proteins and protease in brain, muscle and liver tissues of normal and X-irradiated frogs were determined. Low doses of radiation produced an increment in protein level while high doses produced decrement. However, protease activity at all doses exhibited an elevatory trend. Exposure of frogs to lethal doses resulted in increased protease activity and decreased protein content during post-irradiation periods. The results are discussed on the basis of protein destruction and lysosomal damage. (auth.)

  4. Interference of a short-chain phospholipid with ion transport pathways in frog skin

    DEFF Research Database (Denmark)

    Unmack, M A; Frederiksen, O; Willumsen, N J

    1997-01-01

    The effects of mucosal application of the short-chain phospholipid didecanoyl-L-alpha-phosphatidylcholine (DDPC; with two saturated 10-carbon acyl chains) on active Na+ transport and transepithelial conductance (G) in the frog skin (Rana temporaria) were investigated. Active Na+ transport...... of the frog skin epithelium and opens a paracellular tight junction pathway. Both effects may be caused by incorporation of DDPC in the apical cell membrane....

  5. Pecular Features of Hematopoiesis in the Liver of Mature and Immature Green Frogs (Pelophylax Esculentus Complex

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    Akulenko N. M.

    2016-12-01

    Full Text Available The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex. Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.

  6. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

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    Ximena E. Bernal

    2016-04-01

    Full Text Available Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus, a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp., were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%. This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

  7. Glycogen accumulation in normal and irradiated minced muscle autografts on frog gastrocnemius

    International Nuclear Information System (INIS)

    Malhotra, R.K.; Kaul, R.; Malhotra, N.

    1989-01-01

    Alterations induced in glycogen content and phosphorylase activity have been studied in normal and irradiated minced muscle autografts on frog gastrocnemius at days 1, 3, 5, 7, 10, 15 and 30 postgrafting. The changes observed in the glycogen content and phosphorylase activity conform to the degeneration and regeneration phases of muscle repair. An attempt has been made to explain the altered glycogen utilizing capacities of the frog skeletal muscle during its repair and regeneration. (author)

  8. How minute sooglossid frogs hear without a middle ear.

    Science.gov (United States)

    Boistel, Renaud; Aubin, Thierry; Cloetens, Peter; Peyrin, Françoise; Scotti, Thierry; Herzog, Philippe; Gerlach, Justin; Pollet, Nicolas; Aubry, Jean-François

    2013-09-17

    Acoustic communication is widespread in animals. According to the sensory drive hypothesis [Endler JA (1993) Philos Trans R Soc Lond B Biol Sci 340(1292):215-225], communication signals and perceptual systems have coevolved. A clear illustration of this is the evolution of the tetrapod middle ear, adapted to life on land. Here we report the discovery of a bone conduction-mediated stimulation of the ear by wave propagation in Sechellophryne gardineri, one of the world's smallest terrestrial tetrapods, which lacks a middle ear yet produces acoustic signals. Based on X-ray synchrotron holotomography, we measured the biomechanical properties of the otic tissues and modeled the acoustic propagation. Our models show how bone conduction enhanced by the resonating role of the mouth allows these seemingly deaf frogs to communicate effectively without a middle ear.

  9. Endocrine control of active sodium transport across frog skin

    International Nuclear Information System (INIS)

    Maetz, J.

    1959-01-01

    I. Action of the neurohypophyseal peptides on sodium transport. 1) On Rana Esculenta, oxytocin alone is active on the sodium transport (not vaso pressin). 2) The post hypophysis of R.e. contains an hormonal factor even more specific on Na transport (12 times more active than oxytocin). 3) This new factor must be closely related to oxytocin. II. Action of the adrenal corticoids. 1) The skin of frogs adapted to a salt-rich external medium, shows a considerable diminution in sodium uptake. 2) This decreased sodium uptake is brought back to normal by the injections of aldosterone. 3) This suggests that salt loading of amphibians (as well as mammals) inhibits the mineralocorticoid activity of the adrenals. (author) [fr

  10. Origin of invasive Florida frogs traced to Cuba

    Science.gov (United States)

    Heinicke, Matthew P.; Diaz, Luis M.; Hedges, S. Blair

    2011-01-01

    Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent. PMID:21270024

  11. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

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    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  12. Effects of acute exposure to magnetic field on ionic composition of frog sciatic nerve

    International Nuclear Information System (INIS)

    Salem, A.; Hafedh, A.; Mohsen, S.

    2004-01-01

    Objective: To evaluate the possible interaction between magnetic field and cadmium on ionic composition of frog sciatic nerve. Design: The combined effect of magnetic field and cadmium (1.5mg/kg; in lymphatic sac) were studied in frog sciatic nerves (Rana Esculenta). Sciatic nerve samples were extracted, weighed and mixed in bidistilled water in order to analyze by inductively coupled plasma (ICP) ionic composition. Setting: Frogs (Rana Esculenta) were reared in swimming-pool (Faculte des Sciences de Bizerte, Tunisia). Frogs were cared for under the Tunisian Code of Practice for the Care and Use of Animals for Scientific purpose and the Experimental Protocols were approved by the Ethics Committee. Subjects: Treated and control groups (n=6) weighing 50-100g at the time of experiments were housed in the same condition three weeks before the beginning of the experiments. Results: Acute exposure to magnetic field increased significantly the calcium (+298%, p<0.05) and iron (+50%, p<0.05) contents of frog sciatic nerve, whereas magnesium and copper contents remained unchanged. The association between magnetic field and cadmium, induced marked increase of calcium (+360%, p<0.05), whereas magnesium content remained stable. Conclusions: Magnetic field exposure alters the ionic composition in the frog sciatic nerve, especially calcium and iron. Magnetic field magnifies the effect of cadmium on calcium homeostasis. (author)

  13. Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

    Science.gov (United States)

    Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

    2012-04-01

    Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

  14. Acute Toxicity of a Heavy Metal Cadmium to an Anuran, the Indian Skipper Frog Rana cyanophlyctis

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    Ajai Kumar Srivastav

    2016-08-01

    Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L. At different exposure periods (24, 48, 72 and 96 h, the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of cadmium chloride for the frog R. cyanophlyctis at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.

  15. Speciation in little: the role of range and body size in the diversification of Malagasy mantellid frogs

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    Vences Miguel

    2011-07-01

    diversity. In contrast, small range sizes were unexpectedly associated with a slow-down of mitochondrial substitution rates. Conclusions Based on these results we define a testable hypothesis under which small body sizes result in limited dispersal capabilities and low physiological tolerances, causing smaller and more strongly fragmented ranges. This can be thought to facilitate reproductive isolation and thus favor speciation. Contrary to the expectation of the faster speciation of such microendemic phenotype species, we only found small body sizes of mantellid frogs to be linked to higher diversification and substitution rates, but not small range sizes. A joint analysis of various species-rich regional anuran radiations might provide enough species with all combinations of range and body sizes for a more conclusive test of this hypothesis.

  16. Ecological and genetic divergence between two lineages of Middle American túngara frogs Physalaemus (= Engystomops pustulosus

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    Ron Santiago R

    2010-05-01

    Full Text Available Abstract Background Uncovering how populations of a species differ genetically and ecologically is important for understanding evolutionary processes. Here we combine population genetic methods (microsatellites with phylogenetic information (mtDNA to define genetic population clusters of the wide-spread Neotropical túngara frog (Physalaemus pustulosus. We measure gene flow and migration within and between population clusters and compare genetic diversity between population clusters. By applying ecological niche modeling we determine whether the two most divergent genetic groups of the túngara frog (1 inhabit different habitats, and (2 are separated geographically by unsuitable habitat across a gap in the distribution. Results Most population structure is captured by dividing all sample localities into two allopatric genetic lineages. The Northern genetic lineage (NW Costa Rica is genetically homogenous while the Southern lineage (SW Costa Rica and Panama is sub-divided into three population clusters by both microsatellite and mtDNA analyses. Gene flow is higher within the Northern lineage than within the Southern lineage, perhaps due to increased landscape heterogeneity in the South. Niche modeling reveals differences in suitable habitat between the Northern and Southern lineages: the Northern lineage inhabits dry/pine-oak forests, while the Southern lineage is confined to tropical moist forests. Both lineages seem to have had little movement across the distribution gap, which persisted during the last glacial maximum. The lack of movement was more pronounced for the Southern lineage than for the Northern lineage. Conclusions This study confirms the finding of previous studies that túngara frogs diverged into two allopatric genetic lineages north and south of the gap in the distribution in central Costa Rica several million years ago. The allopatric distribution is attributed to unsuitable habitat and probably other unknown ecological factors

  17. Docosahexaenoate-containing molecular species of glycerophospholipids from frog retinal rod outer segments show different rates of biosynthesis and turnover

    International Nuclear Information System (INIS)

    Louie, K.; Wiegand, R.D.; Anderson, R.E.

    1988-01-01

    The authors have studied the de novo synthesis and subsequent turnover of major docosahexaenoate-containing molecular species in frog rod outer segment (ROS) phospholipids following intravitreal injection of [2- 3 H]glycerol. On selected days after injection, ROS were prepared and phospholipids extracted. Phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) were isolated and converted to diradylglycerols with phospholipase C. Diradylglycerols were derivatized with benzoic anhydride and resolve into diacylglycerobenzoates and ether-linked glycerobenzoates. The diacylglycerobenzoates were fractionated into molecular species by HPLC, quantitated, and counted for radioactivity. Label was incorporated into ROS phospholipids by day 1 and was followed up through the eighth day. The dipolyenoic species 22:6-22:6 from PC showed 1 3-5 times higher radiospecific activity than the same species from either PE or PS. The rate of decline was determined by calculating the half-life of each molecular species, which was used as a measure of the turnover of the species. The percent distribution of radioactivity in the molecular species of PC and PE was quite different from the relative mass distribution at day 1. However, percent dpm approached the mole percent by 31 days. In PS, percent dpm and mole percent were the same at all time points. These results indicate that the molecular species composition of PC and PE in frog retinal ROS is determined by a combination of factors, which include rate of synthesis, rate of degradation, and selective interconversions. In contrast, PS composition appears to be determined at the time of synthesis

  18. Microbiological study of a crushed 'core heart' packaged under sterile atmosphere and isolation of different bacterial strains from the Callovo-Oxfordian argillaceous rock (Bure, France)

    International Nuclear Information System (INIS)

    Mayeux, B.; Daumas, S.; Vinsot, A.; Labat, M.

    2010-01-01

    packed into aluminium bags, which were also flushed and sealed. The samples were shipped to the IRD Laboratory at ambient temperature. Core opening and sub-sampling was conducted within 36 hours after the core was retrieved from the borehole. All tools were sterilized either by autoclaving or flaming with ethanol. These precautions allow sampling the 'core heart' free of any presence of foreign microorganisms in the sample. The core heart was crushed aseptically using a sterilized mortar and pestle in anaerobic conditions. The powder was hydrated with sterile minimal mineral medium (MM) with a low salt concentration. The clay suspension obtained was enriched in different conditions to study the present microflora: - Aerobic: MM with yeast extract or glucose. - Fermentative: MM with yeast extract or glucose but without any presence of oxygen. - Sulfate-reducing: MM with Sodium-sulfate and lactate or acetate (as carbon source). - Thio-sulfato-reducing: MM with Sodium-thiosulfate and lactate or acetate. - Auto-trophic: MM with very low concentration of acetate (to enhance the start of the growth) and with an H 2 /CO 2 (80/20%) atmosphere (CO 2 as source of carbon and H 2 as source of energy). These cultures were performed at 30 deg. C for the mesophilic and 60 deg. C to study the thermophilic microorganisms. As some of the enhancements had been positive, an isolation phase of these various bacteria was performed in Petri dishes for aerobes and Roll-tube for anaerobes (the Roll-Tubes were made from agar poured along the glass-wall and were sterilely and anaerobically closed). Different aerobic strains were selected in which the 16S rRNA gene (ubiquitous gene of the bacteria) was sequenced. The results showed the presence of several strains phylogenetically close to aerobic spore-forming genera (Bacillus, Brevibacillus, Geobacillus) and a non spore-forming strain phylogenetically close to the genus Pseudomonas. One of these isolated strains is a thermo

  19. Efeitos da angiotensina-I e isquemia na recuperação funcional em corações isolados Effects of angiotensin-I and ischemia on functional recovery in isolated hearts

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    Ubirajara Oliveira de Oliveira

    2011-11-01

    dysfunction during reperfusion. OBJECTIVE: To investigate the effects of angiotensin-I and different periods of ischemia on functional recovery in isolated rat hearts. METHODS: Isolated hearts from Wistar rats (n=45; 250-300 g were submitted to different periods of global ischemia (20, 25 or 30 min and reperfused (30 min with Krebs-Henseleit buffer alone or with the addition of 400 nmol/L angiotensin-I, or 400 nmol/L angiotensin-I + 100 mmol/L captopril along the reperfusion period. RESULTS: The maximal positive derivative of pressure (+dP/dt max and rate-pressure product were reduced in hearts exposed to 25 min ischemia (~73% and 30 min ischemia (~80% vs. 20 min ischemia. Left ventricular end-diastolic pressure (LVEDP and perfusion pressure (PP were increased in hearts exposed to 25 min ischemia (5.5 and 1.08 fold, respectively and 30 min ischemia (6 and 1.10 fold, respectively vs. 20 min ischemia. Angiotensin-I caused a decrease in +dP/dt max and rate-pressure product (~85-94% in all ischemic periods and an increase in LVEDP and PP (6.9 and 1.25 fold, respectively only at 20 min ischemia. Captopril was able to partially or completely reverse the effects of angiotensin-I on functional recovery in 20 min and 25 min ischemia. CONCLUSION: These data suggest that angiotensin-II directly or indirectly participates in the post-ischemic damage, and the ability of an ACE inhibitor to attenuate this damage depends on ischemic time.

  20. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

    Science.gov (United States)

    Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

    2008-02-01

    We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  1. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

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    CFD. Rocha

    Full Text Available We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí, Espírito Santo (Praia das Neves and Setiba and Bahia (Prado and Trancoso. We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species, followed by Grussaí and Trancoso (eight species in each. The commonest species in the restingas was Scinax alter (found in eight restingas, followed by Aparasphenodon brunoi (seven areas. Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007. Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  2. Load dependency in force-length relations in isolated single cardiomyocytes.

    Science.gov (United States)

    Iribe, Gentaro; Kaneko, Toshiyuki; Yamaguchi, Yohei; Naruse, Keiji

    2014-08-01

    The previously reported pressure-volume (PV) relationship in frog hearts shows that end-systolic PV relation (ESPVR) is load dependent, whereas ESPVR in canine hearts is load independent. To study intrinsic cardiac mechanics in detail, it is desirable to study mechanics in a single isolated cardiomyocyte that is free from interstitial connective tissue. Previous single cell mechanics studies used a pair of carbon fibers (CF) attached to the upper surface of opposite cell ends to stretch cells. These studies showed that end-systolic force-length (FL) relation (ESFLR) is load independent. However, the range of applicable mechanical load using the conventional technique is limited because of weak cell-CF attachment. Therefore, the behavior of ESFLR in single cells under physiologically possible conditions of greater load is not yet well known. To cover wider loading range, we contrived a new method to hold cell-ends more firmly using two pairs of CF attached to both upper and bottom surfaces of cells. The new method allowed stretching cells to 2.2 μm or more in end-diastolic sarcomere length. ESFLR virtually behaves in a load independent manner only with end-diastolic sarcomere length less than 1.95 μm. It exhibited clear load dependency with higher preload, especially with low afterload conditions. Instantaneous cellular elastance curves showed that decreasing afterload enhanced relaxation and slowed time to peak elastance, as previously reported. A simulation study of a mathematical model with detailed description of thin filament activation suggested that velocity dependent thin filament inactivation is crucial for the observed load dependent behaviors and previously reported afterload dependent change in Ca(2+) transient shape. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Analysis of isolates within species of anuran trypanosomes using random amplified polymorphic DNA.

    Science.gov (United States)

    Lun, Z R; Desser, S S

    1996-01-01

    A total of 20 decamer primers were used to generate random applied polymorphic DNA (RAPD) markers from 5 isolates of Trypanosoma fallisi, 3 isolates of T. ranarum, 2 isolates of T. rotatorium, and 2 isolates of T. rotatorium-like trypanosomes in addition to 2 species from the American Type Culture Collection, T. chattoni (ATCC 50294) and Trypanosoma sp. (ATCC 50295). A slight polymorphism was observed among the four isolates of T. fallisi obtained form American toads, Bufo americanus, collected in Algonquin Park, Ontario, Canada, and an isolate obtained from the same species of host collected in Marquette, Michigan, United States, and produced similarity coefficients ranging from 80.7% to 96.9%. Pronounced polymorphism was recorded among the three isolates of T. ranarum from bullfrogs, Rana catesbeiana, collected in Ontario, Canada, and in Maryland, United States, and from a Northern leopard frog, R. pipiens, collected in Minnesota (USA). The similarity coefficients ranged from 54.7% to 59.5%, suggesting that alleles of these isolates were conserved over a wide geographic range. The high degree of polymorphism observed in two isolates of T. rotatorium from a bullfrog collected in Ontario and two isolates of a T. rotatorium-like parasite from the green frog R. clamitans, collected in Louisiana (USA) suggests that they are different species. These results reflect the high similarity among isolates from the same geographic location and the pronounced polymorphism apparent among isolates from distant geographic locations.

  4. Contractility of isolated hearts from myxedematous rats

    NARCIS (Netherlands)

    Meijler, F.L.

    1963-01-01

    HYPOTHYROIDISM is often complicated by coronary sclerosis and cardiac failure. It is generally believed that the coronary sclerosis is mainly caused by the disturbed lipoid metabolism. The cardiac failure, however, is less well understood. Our findings demonstrate that current concepts about

  5. Heart valve surgery

    Science.gov (United States)

    ... replacement; Valve repair; Heart valve prosthesis; Mechanical valves; Prosthetic valves ... surgery. Your heart valve has been damaged by infection ( endocarditis ). You have received a new heart valve ...

  6. Heart failure - tests

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    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic, diastolic, valvular) Monitor your heart failure and ...

  7. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Science.gov (United States)

    Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

    2015-01-01

    Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

  8. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

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    Edward C. Netherlands

    2015-04-01

    Full Text Available Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01 in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively. Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

  9. Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine

    Science.gov (United States)

    2013-01-01

    Background Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid – P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. Results In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG)n-repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes. Conclusions The constructed cytological maps of lampbrush chromosomes of P

  10. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Netherlands, Edward C; Cook, Courtney A; Kruger, Donnavan J D; du Preez, Louis H; Smit, Nico J

    2015-04-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

  11. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Directory of Open Access Journals (Sweden)

    Corinna E Dreher

    Full Text Available Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and

  12. Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

    Science.gov (United States)

    Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

    2016-04-01

    Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Women's Heart Disease: Heart Attack Symptoms

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Women's Heart Disease Heart Attack Symptoms Past Issues / Winter ... most common heart attack symptom in men and women is chest pain or discomfort. However, women also ...

  14. Heart Health: The Heart Truth Campaign 2009

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story Heart Health The Heart Truth Campaign 2009 Past Issues / Winter 2009 Table ... one of the celebrities supporting this year's The Heart Truth campaign. Both R&B singer Ashanti (center) ...

  15. Heart Health - Heart Disease: Symptoms, Diagnosis, Treatment

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Cover Story Heart Health Heart Disease: Symptoms, Diagnosis, Treatment Past Issues / Winter 2009 ... of this page please turn Javascript on. Most heart attacks happen when a clot in the coronary ...

  16. Women's Heart Disease: Heart Disease Risk Factors

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Women's Heart Disease Heart Disease Risk Factors Past Issues / Winter 2014 Table ... or habits may raise your risk for coronary heart disease (CHD). These conditions are known as risk ...

  17. Geographic Variation in Advertisement Calls in a Tree Frog Species: Gene Flow and Selection Hypotheses

    Science.gov (United States)

    Jang, Yikweon; Hahm, Eun Hye; Lee, Hyun-Jung; Park, Soyeon; Won, Yong-Jin; Choe, Jae C.

    2011-01-01

    Background In a species with a large distribution relative to its dispersal capacity, geographic variation in traits may be explained by gene flow, selection, or the combined effects of both. Studies of genetic diversity using neutral molecular markers show that patterns of isolation by distance (IBD) or barrier effect may be evident for geographic variation at the molecular level in amphibian species. However, selective factors such as habitat, predator, or interspecific interactions may be critical for geographic variation in sexual traits. We studied geographic variation in advertisement calls in the tree frog Hyla japonica to understand patterns of variation in these traits across Korea and provide clues about the underlying forces for variation. Methodology We recorded calls of H. japonica in three breeding seasons from 17 localities including localities in remote Jeju Island. Call characters analyzed were note repetition rate (NRR), note duration (ND), and dominant frequency (DF), along with snout-to-vent length. Results The findings of a barrier effect on DF and a longitudinal variation in NRR seemed to suggest that an open sea between the mainland and Jeju Island and mountain ranges dominated by the north-south Taebaek Mountains were related to geographic variation in call characters. Furthermore, there was a pattern of IBD in mitochondrial DNA sequences. However, no comparable pattern of IBD was found between geographic distance and call characters. We also failed to detect any effects of habitat or interspecific interaction on call characters. Conclusions Geographic variations in call characters as well as mitochondrial DNA sequences were largely stratified by geographic factors such as distance and barriers in Korean populations of H. japoinca. Although we did not detect effects of habitat or interspecific interaction, some other selective factors such as sexual selection might still be operating on call characters in conjunction with restricted gene

  18. Pericarditis - after heart attack

    Science.gov (United States)

    ... include: A previous heart attack Open heart surgery Chest trauma A heart attack that has affected the thickness of your heart muscle Symptoms Symptoms include: Anxiety Chest pain from the swollen pericardium rubbing on the ...

  19. Heart failure - home monitoring

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000113.htm Heart failure - home monitoring To use the sharing features on ... your high blood pressure Fast food tips Heart failure - discharge Heart failure - fluids and diuretics Heart failure - what to ...

  20. Heart Diseases and Disorders

    Science.gov (United States)

    ... Resources Heart Diseases & Disorders Back to Patient Resources Heart Diseases & Disorders Millions of people experience irregular or abnormal ... harmless and happen in healthy people free of heart disease. However, some abnormal heart rhythms can be serious ...

  1. Heart disease and diet

    Science.gov (United States)

    Diet - heart disease; CAD - diet; Coronary artery disease - diet; Coronary heart disease - diet ... diet and lifestyle can reduce your risk of: Heart disease, heart attacks, and stroke Conditions that lead ...

  2. Coronary heart disease

    Science.gov (United States)

    Heart disease, Coronary heart disease, Coronary artery disease; Arteriosclerotic heart disease; CHD; CAD ... buildup of plaque in the arteries to your heart. This may also be called hardening of the ...

  3. Heart attack first aid

    Science.gov (United States)

    First aid - heart attack; First aid - cardiopulmonary arrest; First aid - cardiac arrest ... A heart attack occurs when the blood flow that carries oxygen to the heart is blocked. The heart muscle ...

  4. Structure, synthesis, and activity of dermaseptin b, a novel vertebrate defensive peptide from frog skin: relationship with adenoregulin.

    Science.gov (United States)

    Mor, A; Amiche, M; Nicolas, P

    1994-05-31

    A novel antimicrobial peptide, designated dermaseptin b, was isolated from the skin of the arboreal frog Phyllomedusa bicolor. This 27-residue peptide amide is basic, containing 3 lysine residues that punctuate an alternating hydrophobic and hydrophilic sequence. In helix-inducing solvent, dermaseptin b adopts an amphipathic alpha-helical conformation that most closely resembles class L amphipathic helixes, with all lysine residues on the polar face of the helix. The peptide exhibits growth inhibition activity in vitro against a broad spectrum of pathogenic microorganisms including yeast and bacteria as well as various filamentous fungi that are responsible for severe opportunistic infections accompanying acquired immunodeficiency syndrome and the use of immunosuppressive agents. Maximized pairwise sequence alignment of dermaseptin b and dermaseptin s, a 34-residue antimicrobial peptide previously isolated from Phyllomedusa sauvagii, reveals 81% amino acid identity. No other significant similarity was found between dermaseptin b and any prokaryotic or eukaryotic protein, but similarity was found with adenoregulin (38% amino acid postional identity), a 33-residue peptide that enhances binding of agonists to the A1 adenosine receptor. The synthetic replicates of dermaseptin b and adenoregulin displayed similar but nonidentical spectra of antimicrobial activity, and both peptides were devoid of lytic effect on mammalian cells. Accordingly, the observation that adenoregulin enhances binding of agonists to the adenosine receptor may in fact be a consequence of its ability to alter the structure of biological membranes and to produce signal transduction via interactions with the lipid bilayer, bypassing cell surface receptor interactions.

  5. A Laboratory Experiment on Muscular Metabolism and Fatigue Using the Isolated Frog Muscle Preparation.

    Science.gov (United States)

    Ianuzzo, C. David; And Others

    1987-01-01

    Describes an experiment which demonstrates the association of particular metabolic biochemical changes and muscular fatigue. Highlights applications related to cellular energy metabolism, metabolic regulation, and muscle energetics. (ML)

  6. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

  7. THE MOCHE BOTANICAL FROG (La rana botánica mochica

    Directory of Open Access Journals (Sweden)

    Donna McClelland †

    2011-06-01

    Full Text Available Plants and animals with features which identify them as supernaturals characterize the art of the Precolumbian Moche culture of northern Peru. Among these animals is a frog with feline attributes and a consistent association with manioc tubers, stalks, and plants, the Botanical Frog. The Botanical Frog appears to have been patterned on Leptodactylus pentadactylus. It is shown copulating with felines. Fine line painted vessels and ones with low relief decoration show the Botanical Frog performing as part of a ritual involving other animals and cultivated crops, suggesting that the Botanical Frog was associated with agriculture. ESPAÑOL: El arte de la cultura mochica de la costa norte del Perú presenta plantas y animales mostrando rasgos sobrenaturales. Uno de los animales es una rana con elementos felinos y asociada con tubérculos, ramas y plantas de yuca. La Rana Botánica probablemente tiene su origen en Leptodactylus pentadactylus, una rana carnívora de la selva amazónica. La Rana Botánica copula con felinos y, en vasijas pintadas con líneas finas o con escenarios representados en bajorrelieve, toma parte en ceremonias involucrando a otros animales y cosechas domésticas. Parece ser que la Rana Botánica era un ser sobrenatural asociado con la agricultura.

  8. Evaluation of use of tiletamine/zolazepam for anesthesia of bullfrogs and leopard frogs.

    Science.gov (United States)

    Letcher, J; Durante, R

    1995-07-01

    Use of tiletamine hydrochloride and zolazepam hydrochloride (1:1 fixed ratio combination) as an anesthetic agent in 2 anuran species was studied. A dosage of 5 mg/kg of body weight, administered IM, resulted in variable weak tranquilization. Intramuscular administration at dosages of 10 and 20 mg/kg induced variable states of tranquilization or anesthesia in leopard frogs (Rana pipiens) and bullfrogs (R catesbeiana). The dosages of 50 mg/kg induced anesthesia with greater consistency than lower dosages in bullfrogs, but resulted in mortalities. The same dosage was uniformly fatal in leopard frogs. Neither gross nor histologic lesions were identified in the frogs that died. Depth and duration of anesthesia was dosage related. At the 20 and 50 mg/kg dosages, leopard frogs attained a greater depth of anesthesia and remained anesthetized for a significantly greater duration than did bullfrogs; however, at the 5 and 10 mg/kg dosages, bullfrogs developed greater tranquilization for longer periods than did leopard frogs. Results of this study revealed profound intraspecies variation in depth and duration of effect of tiletamine/zolazepam; therefore, the drug does not appear to be a suitable injectable anesthetic in anurans.

  9. Citizen Science Program Shows Urban Areas Have Lower Occurrence of Frog Species, but Not Accelerated Declines.

    Directory of Open Access Journals (Sweden)

    Martin J Westgate

    Full Text Available Understanding the influence of landscape change on animal populations is critical to inform biodiversity conservation efforts. A particularly important goal is to understand how urban density affects the persistence of animal populations through time, and how these impacts can be mediated by habitat provision; but data on this question are limited for some taxa. Here, we use data from a citizen science monitoring program to investigate the effect of urbanization on patterns of frog species richness and occurrence over 13 years. Sites surrounded by a high proportion of bare ground (a proxy for urbanization had consistently lower frog occurrence, but we found no evidence that declines were restricted to urban areas. Instead, several frog species showed declines in rural wetlands with low-quality habitat. Our analysis shows that urban wetlands had low but stable species richness; but also that population trajectories are strongly influenced by vegetation provision in both the riparian zone and the wider landscape. Future increases in the extent of urban environments in our study area are likely to negatively impact populations of several frog species. However, existing urban areas are unlikely to lose further frog species in the medium term. We recommend that landscape planning and management focus on the conservation and restoration of rural wetlands to arrest current declines, and the revegetation of urban wetlands to facilitate the re-expansion of urban-sensitive species.

  10. Propulsive efficiency of frog swimming with different feet and swimming patterns

    Directory of Open Access Journals (Sweden)

    Fan Jizhuang

    2017-04-01

    Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

  11. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    Directory of Open Access Journals (Sweden)

    Brett R. Scheffers

    2014-12-01

    Full Text Available Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of various sizes to identify relationships between water and temperature buffering. Ferns are the preferred diurnal microhabitat and breeding habitat for arboreal frogs. A strong positive relationship exists between fern size and frog usage and abundance. Our drying experiments show that large ferns buffer maximum temperatures and reduce variability in temperatures, and buffering is directly linked to their hydration. Frogs are likely using large ferns for their moist, cool, environments for breeding and daytime retreat, which supports the buffered microhabitat hypothesis—these plants promote species coexistence through habitat creation and amelioration of physical stress. However, drying experiments suggest that this buffering is contingent on regular rainfall. Altered rainfall regimes could lead to the unexpected loss of the functional capacity of these important fern habitats. Keywords: Climate change, Functionality, Microhabitat, Refuge, Ectotherm, Precipitation

  12. Factors influencing survival and mark retention in postmetamorphic boreal chorus frogs

    Science.gov (United States)

    Swanson, Jennifer E; Bailey, Larissa L.; Muths, Erin L.; Funk, W. Chris

    2013-01-01

    The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer and photo identification. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphosed individuals and as a result little is known about this life-history phase for most amphibians. Our focus was to explore survival probabilities, mark retention, and mark migration in postmetamorphic Boreal Chorus Frogs (Psuedacris maculata) in a laboratory setting. One hundred forty-seven individuals were assigned randomly to two treatment groups or a control group. Frogs in the first treatment group were marked with visual implant elastomer, while frogs in the second treatment group were toe clipped. Growth and mortality were recorded for one year and resulting data were analyzed using known-fate models in Program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. We found that frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in other treatments, but individuals can be marked by clipping a single toe on two different feet without any mark loss or negative survival effects. Individuals treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6%, and also showed very little negative survival impacts relative to control individuals.

  13. Severe right heart failure in a patient with Grave's disease.

    Science.gov (United States)

    Xenopoulos, N P; Braden, G A; Applegate, R J

    1996-11-01

    This brief report presents a patient with isolated right heart failure and two rare underlying causes, hyperthyroidism and dysplastic tricuspid valve. Repair of the tricuspid valve and treatment of the hyperthyroidism were both essential for successful treatment of the right heart failure. Most important, recrudescence of hyperthyroidism in this patient was associated with reappearance of florid right heart failure. This report provides further information about a potential linkage of hyperthyroidism and severe right heart failure.

  14. AcT-2: a novel myotropic and antimicrobial type 2 tryptophyllin from the skin secretion of the Central American red-eyed leaf frog, Agalychnis callidryas.

    Science.gov (United States)

    Ge, Lilin; Lyu, Peng; Zhou, Mei; Zhang, Huiling; Wan, Yuantai; Li, Bin; Li, Renjie; Wang, Lei; Chen, Tianbao; Shaw, Chris

    2014-01-01

    Tryptophyllins are a diverse family of amphibian peptides originally found in extracts of phyllomedusine frog skin by chemical means. Their biological activities remain obscure. Here we describe the isolation and preliminary pharmacological characterization of a novel type 2 tryptophyllin, named AcT-2, from the skin secretion of the red-eyed leaf frog, Agalychnis callidryas. The peptide was initially identified during smooth muscle pharmacological screening of skin secretion HPLC fractions and the unique primary structure--GMRPPWF-NH2--was established by both Edman degradation and electrospray MS/MS fragmentation sequencing. A. cDNA encoding the biosynthetic precursor of AcT-2 was successfully cloned from a skin secretion-derived cDNA library by means of RACE PCR and this contained an open-reading frame consisting of 62 amino acid residues with a single AcT-2 encoding sequence located towards the C-terminus. A synthetic replicate of AcT-2 was found to relax arterial smooth muscle (EC50 = 5.1 nM) and to contract rat urinary bladder smooth muscle (EC50 = 9.3 μ M). The peptide could also inhibit the growth of the microorganisms, Staphylococcus aureus, (MIC = 256 mg/L) Escherichia coli (MIC = 512 mg/L), and Candida albicans (128 mg/L). AcT-2 is thus the first amphibian skin tryptophyllin found to possess both myotropic and antimicrobial activities.

  15. AcT-2: A Novel Myotropic and Antimicrobial Type 2 Tryptophyllin from the Skin Secretion of the Central American Red-Eyed Leaf Frog, Agalychnis callidryas

    Directory of Open Access Journals (Sweden)

    Lilin Ge

    2014-01-01

    Full Text Available Tryptophyllins are a diverse family of amphibian peptides originally found in extracts of phyllomedusine frog skin by chemical means. Their biological activities remain obscure. Here we describe the isolation and preliminary pharmacological characterization of a novel type 2 tryptophyllin, named AcT-2, from the skin secretion of the red-eyed leaf frog, Agalychnis callidryas. The peptide was initially identified during smooth muscle pharmacological screening of skin secretion HPLC fractions and the unique primary structure—GMRPPWF-NH2—was established by both Edman degradation and electrospray MS/MS fragmentation sequencing. A. cDNA encoding the biosynthetic precursor of AcT-2 was successfully cloned from a skin secretion-derived cDNA library by means of RACE PCR and this contained an open-reading frame consisting of 62 amino acid residues with a single AcT-2 encoding sequence located towards the C-terminus. A synthetic replicate of AcT-2 was found to relax arterial smooth muscle (EC50 = 5.1 nM and to contract rat urinary bladder smooth muscle (EC50 = 9.3 μM. The peptide could also inhibit the growth of the microorganisms, Staphylococcus aureus, (MIC = 256 mg/L Escherichia coli (MIC = 512 mg/L, and Candida albicans (128 mg/L. AcT-2 is thus the first amphibian skin tryptophyllin found to possess both myotropic and antimicrobial activities.

  16. Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

    Science.gov (United States)

    Delfino, Massimo

    2017-07-13

    Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    Science.gov (United States)

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  18. Chiricahua leopard frog status in the Galiuro Mountains, Arizona, with a monitoring framework for the species' entire range

    Science.gov (United States)

    Lawrence L. C. Jones; Michael J. Sredl

    2005-01-01

    The Chiricahua leopard frog (Rana chiricahuensis) was historically widespread in suitable habitat throughout its range. Reports of recent population declines led to inventories of Chiricahua leopard frog localities. Surveys reported here establish a new baseline of occurrence in the Galiuros: only two of 21 historical localities were found to be...

  19. Viability of Vibrio cholerae 01 on frog legs under frozen and refrigerated conditions and low dose radiation treatment

    International Nuclear Information System (INIS)

    Sang, F.C.; Hugh-Jones, M.E.; Hagstad, H.V.

    1987-01-01

    Frog legs were contaminated with Vibrio cholerae 01, Inaba serotype, EITor biotype. The organism remained viable for more than 28 and 2 d when stored at -20°C and 4°C, respectively. Exposure to a multicuries 60 Cobalt source of 50 and 100 kilorads eliminated V. cholerae from both the frozen and fresh frog legs

  20. Phylogenomics reveals rapid, simultaneous diversification of three major clades of Gondwanan frogs at the Cretaceous-Paleogene boundary.

    Science.gov (United States)

    Feng, Yan-Jie; Blackburn, David C; Liang, Dan; Hillis, David M; Wake, David B; Cannatella, David C; Zhang, Peng

    2017-07-18

    Frogs (Anura) are one of the most diverse groups of vertebrates and comprise nearly 90% of living amphibian species. Their worldwide distribution and diverse biology make them well-suited for assessing fundamental questions in evolution, ecology, and conservation. However, despite their scientific importance, the evolutionary history and tempo of frog diversification remain poorly understood. By using a molecular dataset of unprecedented size, including 88-kb characters from 95 nuclear genes of 156 frog species, in conjunction with 20 fossil-based calibrations, our analyses result in the most strongly supported phylogeny of all major frog lineages and provide a timescale of frog evolution that suggests much younger divergence times than suggested by earlier studies. Unexpectedly, our divergence-time analyses show that three species-rich clades (Hyloidea, Microhylidae, and Natatanura), which together comprise ∼88% of extant anuran species, simultaneously underwent rapid diversification at the Cretaceous-Paleogene (K-Pg) boundary (KPB). Moreover, anuran families and subfamilies containing arboreal species originated near or after the KPB. These results suggest that the K-Pg mass extinction may have triggered explosive radiations of frogs by creating new ecological opportunities. This phylogeny also reveals relationships such as Microhylidae being sister to all other ranoid frogs and African continental lineages of Natatanura forming a clade that is sister to a clade of Eurasian, Indian, Melanesian, and Malagasy lineages. Biogeographical analyses suggest that the ancestral area of modern frogs was Africa, and their current distribution is largely associated with the breakup of Pangaea and subsequent Gondwanan fragmentation.

  1. Pediatric heart surgery

    Science.gov (United States)

    Heart surgery - pediatric; Heart surgery for children; Acquired heart disease; Heart valve surgery - children ... There are many kinds of heart defects. Some are minor, and others are more serious. Defects can occur inside the heart or in the large blood vessels ...

  2. Environmental constraints and call evolution in torrent-dwelling frogs.

    Science.gov (United States)

    Goutte, Sandra; Dubois, Alain; Howard, Samuel D; Marquez, Rafael; Rowley, Jodi J L; Dehling, J Maximilian; Grandcolas, Philippe; Rongchuan, Xiong; Legendre, Frédéric

    2016-04-01

    Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  3. Synthesis of nanoparticles with frog foam nest proteins

    International Nuclear Information System (INIS)

    Choi, Hyo-Jick; Ebersbacher, Charles F.; Myung, Nosang V.; Montemagno, Carlo D.

    2012-01-01

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water–oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8–10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  4. Synthesis of nanoparticles with frog foam nest proteins

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyo-Jick, E-mail: choihc@ucmail.uc.edu; Ebersbacher, Charles F. [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States); Myung, Nosang V. [University of California, Riverside, Department of Chemical and Environmental Engineering (United States); Montemagno, Carlo D., E-mail: montemcd@ucmail.uc.edu [University of Cincinnati, School of Energy, Environmental, Biological and Medical Engineering (United States)

    2012-09-15

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water-oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8-10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  5. Synthesis of nanoparticles with frog foam nest proteins

    Science.gov (United States)

    Choi, Hyo-Jick; Ebersbacher, Charles F.; Myung, Nosang V.; Montemagno, Carlo D.

    2012-09-01

    Microemulsions provide an efficient means of synthesizing monodispersed nanoparticles. Recent studies have demonstrated potential problems of surfactant due to the interaction with nanoparticles/precursors. To solve the problems, various types of chemical surfactants have been tested, but natural biosurfactants have not received a great deal of attention in engineering application. Here, we report the formation of microemulsions using frog foam nest protein, ranaspumin-2 (RSN-2), based on the hypothesis that RSN-2 assembles at the water-oil interface as a result of conformational change into an extended form. Fluorescence spectroscopic studies showed that RSN-2 undergoes a reversible transition between extended and globular conformation in foams/microemulsions and aqueous solution, respectively. Microemulsions were formulated with RSN-2 to synthesize 8-10 nm superparamagnetic iron oxide nanoparticles by mixing precursor-containing microemulsions with base-containing microemulsions. RSN-2 proteins were recovered from microemulsions and found to be recycled to make foams and microemulsions. Fluorescence spectroscopic analyses showed that RSN-2 maintained its mechanical agitation-induced amphiphilicity throughout multiple foaming/defoaming processes. These results suggest that conformational flexibility and structural stability of RSN-2 in aggressive environments enable the recycled use of RSN-2, elucidating the cost-effective advantage.

  6. Birds and frogs selected papers, 1990-2014

    CERN Document Server

    Dyson, Freeman J

    2015-01-01

    This book is a sequel to the volume of selected papers of Dyson up to 1990 that was published by the American Mathematical Society in 1996. The present edition comprises a collection of the most interesting writings of Freeman Dyson, all personally selected by the author, from the period 1990–2014. The five sections start off with an Introduction, followed by Talks about Science, Memoirs, Politics and History, and some Technical Papers. The most noteworthy is a lecture entitled Birds and Frogs to the American Mathematical Society that describes two kinds of mathematicians with examples from real life. Other invaluable contributions include an important tribute to C. N. Yang written for his retirement banquet at Stony Brook University, as well as a historical account of the Operational Research at RAF Bomber Command in World War II provocatively titled A Failure of Intelligence. The final section carries the open-ended question of whether any conceivable experiment could detect single gravitons to provide d...

  7. Habitat selection, movement patterns, and hazards encountered by northern leopard frogs (Lithobates pipiens) in an agricultural landscape

    Science.gov (United States)

    Knutson, Melinda G.; Herner-Thogmartin, Jennifer H.; Thogmartin, Wayne E.; Kapfer, Joshua M.; Nelson, John

    2018-01-01

    Telemetry data for 59 Northern Leopard Frogs (Lithobates pipiens) breeding in ponds in Houston and Winona Counties, MN; 2001-2002. Agricultural intensification is causing declines in many wildlife species, including Northern Leopard Frogs (Lithobates pipiens). Specific information about frog movements, habitat selection, and sources of mortality can be used to inform conservation-focused land management and acquisition. We studied Northern Leopard Frogs in southeastern Minnesota, part of the Driftless Area ecoregion, characterized by hills and valleys and a mix of agriculture, forests, small towns and farmsteads. In this area, small farm ponds, originally built to control soil erosion are used by the species for breeding and wintering in addition to riparian wetlands. But, this agricultural landscape may be hazardous for frogs moving between breeding, feeding, and wintering habitats. We surgically implanted transmitters into the peritoneal cavity of 59 Northern Leopard Frogs and tracked them from May to October 2001-2002. The total distance traveled by radio-tagged frogs ranged from 12 to 3316 m, the 95% home range averaged 5.3 ± 1.2 (SE) ha, and the 50% core area averaged 1.05 ± 0.3 (SE) ha. As expected, Northern Leopard Frogs selected wetlands over all other land cover classes and row crops were generally avoided at all levels of selection. Only a few tracked frogs were successful at dispersing (n = 6). Most frogs attempting to disperse (n =31) ended up missing (n = 14), died due to mowing (n = 8), or were recorded as transmitter failure (n = 2) or unknown mortalities (n = 1). For the conservation of Northern Leopard Frogs in this agricultural setting, we must consider both the aquatic and the terrestrial needs of this species. Conservation agencies that restore, manage, and acquire wetlands should consider the hazards posed by land uses adjacent to frog breeding and wintering sites and plan for movement corridors between these locations. For example

  8. A success model and implementation on examining teacher’s attitude in using frog virtual learning environment

    Directory of Open Access Journals (Sweden)

    Wan Rozaini Sheik Osman

    2017-12-01

    Full Text Available The Frog Virtual Learning Environment (Frog VLE together with school administrators, teachers, students and parents has formed the concept of a virtual community within the school environment. The research uses a qualitative approach that involves interviewing four selected teachers in a primary school located in the district of Baling/ Sik, Kedah. The study employs a structured questionnaire as an interview protocol instrument. The questionnaires were also distributed to sixteen other teachers to compare the responses. The findings showed that teachers were using Frog VLE application and it helps in teaching and learning. Frog VLE also motivates teachers to teach better. However, not all teachers are comfortable using it because there are many obstacles and constraints that teachers face when applying them. The analysis of result from the teacher’s attitude indicated that there was an important relationship between the teacher’s basic knowledge of ICT and the skills in accessing the Frog VLE.

  9. FROG ASSEMBLAGE ASSOCIATED WITH BROMELIADS IN A SANDY COASTAL PLAIN IN THE STATE OF ESPÍRITO SANTO, SOUTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    MARCIO MARQUES MAGESKI

    Full Text Available ABSTRACT Amphibians may use bromeliads for reproduction (i.e., bromeligenous species or only for refuge and foraging (i.e., bromelicolous species. The partition of bromeliad resources is essential to maintain the coexistence of the associated assemblages. We sampled 913 bromeliads in a sandy coastal plain (i.e., restinga habitat in southeastern Brazil and found 234 frogs belonging to seven species. One of the frog species was bromeligenous and the other six were facultative bromelicolous. The bromeliads of the genus Aechmea were the most frequently used by frogs. The low degree of frog occupancy of bromeliads (26% suggests habitat segregation. Our study highlights the importance of maintenance of bromeliad species for conservation of the associated frog assemblages.

  10. [Genetics of congenital heart diseases].

    Science.gov (United States)

    Bonnet, Damien

    2017-06-01

    Developmental genetics of congenital heart diseases has evolved from analysis of serial slices in embryos towards molecular genetics of cardiac morphogenesis with a dynamic view of cardiac development. Genetics of congenital heart diseases has also changed from formal genetic analysis of familial recurrences or population-based analysis to screening for mutations in candidates genes identified in animal models. Close cooperation between molecular embryologists, pathologists involved in heart development and pediatric cardiologists is crucial for further increase of knowledge in the field of cardiac morphogenesis and genetics of cardiac defects. The genetic model for congenital heart disease has to be revised to favor a polygenic origin rather than a monogenic one. The main mechanism is altered genic dosage that can account for heart diseases in chromosomal anomalies as well as in point mutations in syndromic and isolated congenital heart diseases. The use of big data grouping information from cardiac development, interactions between genes and proteins, epigenetic factors such as chromatin remodeling or DNA methylation is the current source for improving our knowledge in the field and to give clues for future therapies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. Model-based analyses reveal insular population diversification and cryptic frog species in the Ischnocnema parva complex in the Atlantic forest of Brazil.

    Science.gov (United States)

    Gehara, Marcelo; Barth, Adriane; Oliveira, Eliana Faria de; Costa, Marco Antonio; Haddad, Célio Fernando Baptista; Vences, Miguel

    2017-07-01

    The Atlantic Forest (AF) of Brazil has long been recognized as a biodiversity conservation hotspot. Despite decades of studies the species inventory of this biome continues to increase with the discovery of cryptic diversity and the description of new species. Different diversification mechanisms have been proposed to explain the diversity in the region, including models of forest dynamics, barriers to gene flow and dispersal. Also, sea level change is thought to have influenced coastal diversification and isolated populations on continental islands. However, the timing and mode of diversification of insular populations in the AF region were rarely investigated. Here, we analyze the phylogeography and species diversity of the small-sized direct-developing frog Ischnocnema parva. These frogs are independent from water bodies but dependent on forest cover and high humidity, and provide good models to understand forest dynamics and insular diversification. Our analysis was based on DNA sequences for one mitochondrial and four nuclear genes of 71 samples from 18 localities including two islands, São Sebastião, municipality of Ilhabela, and Mar Virado, municipality of Ubatuba, both in the state of São Paulo. We use molecular taxonomic methods to show that I. parva is composed of six independently evolving lineages, with the nominal I. parva likely endemic to the type locality. The time-calibrated species tree shows that these lineages have diverged in the Pliocene and Pleistocene, suggesting the persistence of micro-refuges of forest in the AF. For the two insular populations we used approximate Bayesian computation to test different diversification hypotheses. Our findings support isolation with migration for São Sebastião population, with ∼1Mya divergence time, and isolation without migration for Mar Virado population, with ∼13Kya divergence time, suggesting a combination of different processes for diversification on AF islands. Copyright © 2017. Published

  12. Columbia spotted frog (Rana luteiventris) in southeastern Oregon: A survey of historical localities, 2009

    Science.gov (United States)

    Pearl, Chistopher A.; Galvan, Stephanie K.; Adams, Michael J.; McCreary, Brome

    2010-01-01

    The Columbia spotted frog (Rana luteiventris) occupies a large range in western North America and is comprised of at least three genetic units. Concern exists regarding the status of the Great Basin populations in Oregon, Idaho, and Nevada. We surveyed target and nearby alternate sites on public lands in southeastern Oregon where there was evidence that Columbia spotted frogs were historically present. We found the species at 59.5 percent (25 of 42) of target or nearby alternate sites. They were in 15 of 23 permanent streams and 8 of 13 intermittent streams. Our surveys do not provide evidence of widespread population losses in our sites. Interpretation of status of Columbia spotted frogs in this study is limited by a lack of precision in some of the historical locations and by our inability to determine if locations where only adults were indicated in the historical record once had breeding populations. Our results support the need for continued investigation of these populations.

  13. Field guide to malformations of frogs and toads: with radiographic interpretations

    Science.gov (United States)

    Meteyer, Carol U.

    2000-01-01

    In 1995, students found numerous malformed frogs on a field trip to a Minnesota pond. Since that time, reports of malformed frogs have increased dramatically. Malformed frogs have now been reported in 44 states in 38 species of frogs, and 19 species of toads. Estimates as high as 60% of the newly metamorphosed frog populations have had malformations at some ponds (NARCAM, ’99). The wide geographic distribution of malformed frogs and the variety of malformations are a concern to resource managers, research scientists and public health officials. The potential for malformations to serve as a signal of ecosystem disruption, and the affect this potential disruption might have on other organisms that share those ecosystems, has not been resolved. Malformations represent an error that occurred early in development. The event that caused the developmental error is temporally distant from the malformation we see in the fully developed animal. Knowledge of normal developmental principles is necessary to design thoughtful investigations that will define the events involved in abnormal development in wild frog populations.Development begins at the time an egg is fertilized and progresses by chemical communication between cells and cell layers. This communication is programmed through gene expression. Malformations represent primary errors in development, errors in chemical communication or translation of genetic information. Deformations arise later in development and usually result from the influence of mechanical factors (such as amputation) that alter shape or anatomy of a structure that has developed normally. The occurrence and the type of malformations are influenced by the type of error or insult as well as the timing of the error (the developmental stage at which the error occurred). The appearance of the malformation can therefore provide clues that suggest when the error may have occurred. If the malformation is an incomplete organ, such as an incomplete limb, the

  14. Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

    Science.gov (United States)

    Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

    2011-06-23

    Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

  15. Reciprocal Trophic Interactions and Transmission of Blood Parasites between Mosquitoes and Frogs

    Directory of Open Access Journals (Sweden)

    Todd G. Smith

    2012-04-01

    Full Text Available The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species.

  16. Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

    Science.gov (United States)

    Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

    2013-12-01

    Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary

  17. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria).

    Science.gov (United States)

    Strong, Rebecca J; Halsall, Crispin J; Ferenčík, Martin; Jones, Kevin C; Shore, Richard F; Martin, Francis L

    2016-06-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpoles collected from ponds with differing water quality. Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site. Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination. Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Cardioplegia using low volumic cardioplegic agents: morphological study in isolated rabbit hearts Cardioplegia utilizando baixo volume de agentes cardioplégicos: estudo morfológico em coração isolado de coelhos

    Directory of Open Access Journals (Sweden)

    Ana Paula Marques Lima-Oliveira

    2003-09-01

    Full Text Available INTRODUCTION: Pharmacological cardioplegic solution aims to eliminate the consequences of ischemic damage, which results from the misbalance between the offer and consumption of energy during the arrest of the heart beats during cardiac surgery with cardiopulmonary bypass. OBJECTIVES: This research experimentally evaluates the structural and ultrastructural changes in isolated rabbit hearts submitted to arrest protected by a Low Volumetric Cardioplegic Solution (LVCS. MATERIAL AND METHOD: The study counted with a control group and two experimental groups. In group I the cardiac arrest was obtained by infusion of the LVCS for 2 hours. In group II the experiment was conducted in the same way until the arrest protected by LVCS for 2 hours, and immediately after reperfusion was performed with the Ringer Locke (RL oxygenated solution for 1 hour. In the control group the hearts were perfused with the RL oxygenated solution for 2 hours. After the experiments, 8 samples of the left ventricle were fixed in 10% formaldehyde and 2.5% glutaraldehyde for histological and ultrastructural analysis. RESULTS: The myocardial cells, the fibroblasts and the endothelial cells which were observed in the experimental groups I and II, presented with marginalization of the heterochromatin, compaction of the nucleolus, change in the morphology of the mitochondria and compaction of the cristae. Also there was an increase of the density of the mitochondrial matrix. This indicates that the nuclear structure as well as the structure of the cytoplasmic organelles were altered when compared to the cells of the control group. CONCLUSION: The structural modifications were due a physiological adaptation of the cell, and not an indication of oncosis or apoptosis, suggesting that the cardioplegic solution used was efficient for the preservation of the cells.INTRODUÇÃO: A solução cardioplégica farmacológica busca eliminar as conseqüências do dano isquêmico, que é o

  19. The Australasian frog family Ceratobatrachidae in China, Myanmar and Thailand: discovery of a new Himalayan forest frog clade

    Science.gov (United States)

    YAN, Fang; JIANG, Ke; WANG, Kai; JIN, Jie-Qiong; SUWANNAPOOM, Chatmongkon; LI, Cheng; Jens, V. VINDUM; Rafe, M. BROWN; CHE, Jing

    2016-01-01

    In an effort to study the systematic affinities and specieslevel phylogenetic relationships of the enigmatic anurans variably assigned to the genera Ingerana or Limnonectes (family Dicroglossidae), we collected new molecular sequence data for five species including four Himalayan taxa, Limnonectes xizangensis, Lim. medogensis, Lim. alpine, Ingerana borealis and one southeast Asian species, I. tasanae, and analyzed these together with data from previous studies involving other ostensibly related taxa. Our surprising results demonstrate unequivocally that Lim. xizangensis, Lim. medogensis and Lim. alpine form a strongly supported clade, the sister-group of the family Australasian forest frog family Ceratobatrachidae. This discovery requires an expansion of the definition of Ceratobatrachidae and represents the first record of this family in China. These three species are distinguished from the species of Ingerana and Limnonectes by the: (1) absence of interdigital webbing of the foot, (2) absence of terminal discs on fingers and toes, (3) absence of circumarginal grooves on the fingers and toes, and (4) absence of tarsal folds. Given their phylogenetic and morphological distinctiveness, we assign them to the oldest available generic name for this clade, Liurana Dubois 1987, and transfer Liurana from Dicroglossidae to the family Ceratobatrachidae. In contrast, Ingerana tasanae was found to be clustered with strong support with the recently described genus Alcalus (Ceratobatrachidae), a small clade of otherwise Sundaic species; this constitutes a new record of the family Ceratobatrachidae for Myanmar and Thailand. Finally, Ingerana borealis clustered with the "true" Ingerana (family Dicroglossidae), for which the type species is I. tenasserimensis. PMID:26828029

  20. The potential effects of climate change on the status of Seychelles frogs (Anura: Sooglossidae

    Directory of Open Access Journals (Sweden)

    J. Gerlach

    2011-11-01

    Full Text Available The status of the Seychelles frogs of the family Sooglossidae was investigated, using monitoring data from 1993-2010, climate data from 1998-2010 and studies of populations and local climate effects. Climate monitoring at each plot covered rainfall and temperature, with leaf wetness and soil moisture being monitored additionally at one site. Analysis of the data and ecological modelling of the distribution identify geographical patterns in climate which explain the present distribution of the different sooglossid species. In addition it identifies a drying trend in the first quarter of the year which corresponds to frog population declines in mid-altitude forests. This is interpreted as evidence of an ongoing deterioration in the suitability of habitats for the frogs, with declines recorded in areas of marginal suitability. By extension it is assumed that currently optimal frog habitat is also undergoing a decline in suitability, due to early year decreases in moisture. Projected changes in climate were used to predict changes in ranges of the sooglossids over the next 90 years. This predicts significant declines, with the possible extinction of the palm frog Sooglossus pipilodryas by 2100. Accordingly all four sooglossid species should be categorised as Endangered, rather than their current status of Vulnerable. Captive assurance colonies have not been successfully established to date. Captive groups have been maintained with a high degree of success but breeding has not been recorded so far. Further work needed for the conservation of the frogs is outlined: development of a reliable method of monitoring the cryptic S. thomasseti and development of captive breeding techniques.

  1. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    Science.gov (United States)

    Netherlands, Edward C.; Cook, Courtney A.; Kruger, Donnavan J.D.; du Preez, Louis H.; Smit, Nico J.

    2015-01-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity. PMID:25830113

  2. Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

    Science.gov (United States)

    Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

    2008-09-01

    Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

  3. Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

    Science.gov (United States)

    Smalling, Kelly L; Reeves, Rebecca; Muths, Erin; Vandever, Mark; Battaglin, William A; Hladik, Michelle L; Pierce, Clay L

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1,500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing

  4. Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

    Science.gov (United States)

    Smalling, Kelly L.; Reeves, Rebecca; Muths, Erin L.; Vandever, Mark W.; Battaglin, William A.; Hladik, Michelle; Pierce, Clay L.

    2015-01-01

    Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and

  5. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis

    International Nuclear Information System (INIS)

    Zhang Hangjun; Cai Chenchen; Shi Cailei; Cao Hui; Han Ziliu; Jia Xiuying

    2012-01-01

    Highlights: ► Cd can cause vacuoles and deformity of the spermatogenic cells in the frog testes. ► Cd can result in oxidative stress in the frog testes. ► Cd can induce significantly increase of ROS contents triggered DNA damages in the frog testes. ► Cd can cause apoptosis in the testes of male R. limnocharis. ► Apoptosis by Cd in the frog testes is related to Caspase-3, Bax and Bcl-2 genes. - Abstract: This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose–effect relationship. Moreover, the same dosages of Cd 2+ solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P < 0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5–7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P < 0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species.

  6. The redesigned Forensic Research/Reference on Genetics-knowledge base, FROG-kb.

    Science.gov (United States)

    Kidd, Kenneth K; Soundararajan, Usha; Rajeevan, Haseena; Pakstis, Andrew J; Moore, Katherine N; Ropero-Miller, Jeri D

    2018-03-01

    The Forensic Resource/Reference on Genetics-knowledge base (FROG-kb) web site was introduced in 2011 and in the five years since the previous publication ongoing research into how the database can better serve forensics has resulted in extensive redesign of the database interface and functionality. Originally designed as a prototype to support forensic use of single nucleotide polymorphisms (SNPs), FROG-kb provides a freely accessible web interface that facilitates forensic practice and can be useful for teaching and research. Based on knowledge gained through its use, the web interface has been redesigned for easier navigation through the multiple components. The site also has functional enhancements, extensive new documentation, and new reference panels of SNPs with new curated data. FROG-kb focuses on single nucleotide polymorphisms (SNPs) and provides reference population data for several published panels of individual identification SNPs (IISNPs) and several published panels of ancestry inference SNPs (AISNPs). For each of the various marker panels with reference population data, FROG-kb calculates random match probabilities (RMP) and relative likelihoods of ancestry for a user-entered genotype profile (either completely or partially specified). Example genotype profiles are available and the User's Manual presents interpretation guidelines for the calculations. The extensive documentation along with ongoing updates makes FROG-kb a comprehensive tool in facilitating use of SNPs in forensic practice and education. An overview of the new FROG-kb with examples and material explaining the results of its use are presented here. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Introducing the Forensic Research/Reference on Genetics knowledge base, FROG-kb.

    Science.gov (United States)

    Rajeevan, Haseena; Soundararajan, Usha; Pakstis, Andrew J; Kidd, Kenneth K

    2012-09-01

    Online tools and databases based on multi-allelic short tandem repeat polymorphisms (STRPs) are actively used in forensic teaching, research, and investigations. The Fst value of each CODIS marker tends to be low across the populations of the world and most populations typically have all the common STRP alleles present diminishing the ability of these systems to discriminate ethnicity. Recently, considerable research is being conducted on single nucleotide polymorphisms (SNPs) to be considered for human identification and description. However, online tools and databases that can be used for forensic research and investigation are limited. The back end DBMS (Database Management System) for FROG-kb is Oracle version 10. The front end is implemented with specific code using technologies such as Java, Java Servlet, JSP, JQuery, and GoogleCharts. We present an open access web application, FROG-kb (Forensic Research/Reference on Genetics-knowledge base, http://frog.med.yale.edu), that is useful for teaching and research relevant to forensics and can serve as a tool facilitating forensic practice. The underlying data for FROG-kb are provided by the already extensively used and referenced ALlele FREquency Database, ALFRED (http://alfred.med.yale.edu). In addition to displaying data in an organized manner, computational tools that use the underlying allele frequencies with user-provided data are implemented in FROG-kb. These tools are organized by the different published SNP/marker panels available. This web tool currently has implemented general functions possible for two types of SNP panels, individual identification and ancestry inference, and a prediction function specific to a phenotype informative panel for eye color. The current online version of FROG-kb already provides new and useful functionality. We expect FROG-kb to grow and expand in capabilities and welcome input from the forensic community in identifying datasets and functionalities that will be most helpful

  8. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob

    2014-01-01

    by individuals to generate their observed population behaviour. A number of existing agent-modelling frameworks are considered, but none have the ability to handle large numbers of time-dependent event-generating agents; hence the construction of a new tool, RANA. The calling behaviour of the Puerto Rican Tree...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

  9. Early-Life Diet Affects Host Microbiota and Later-Life Defenses Against Parasites in Frogs.

    Science.gov (United States)

    Knutie, Sarah A; Shea, Lauren A; Kupselaitis, Marinna; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

    2017-10-01

    Food resources can affect the health of organisms by altering their symbiotic microbiota and affecting energy reserves for host defenses against parasites. Different diets can vary in their macronutrient content and therefore they might favor certain bacterial communities of the host and affect the development and maintenance of the immune system, such as the inflammatory or antibody responses. Thus, testing the effect of diet, especially for animals with wide diet breadths, on host-associated microbiota and defenses against parasites might be important in determining infection and disease risk. Here, we test whether the early-life diet of Cuban tree frogs (Osteopilus septentrionalis) affects early- and later-life microbiota as well as later-life defenses against skin-penetrating, gut worms (Aplectana hamatospicula). We fed tadpoles two ecologically common diets: a diet of conspecifics or a diet of algae (Arthrospira sp.). We then: (1) characterized the gut microbiota of tadpoles and adults; and (2) challenged adult frogs with parasitic worms and measured host resistance (including the antibody-mediated immune response) and tolerance of infections. Tadpole diet affected bacterial communities in the guts of tadpoles but did not have enduring effects on the bacterial communities of adults. In contrast, tadpole diet had enduring effects on host resistance and tolerance of infections in adult frogs. Frogs that were fed a conspecific-based diet as tadpoles were more resistant to worm penetration compared with frogs that were fed an alga-based diet as tadpoles, but less resistant to worm establishment, which may be related to their suppressed antibody response during worm establishment. Furthermore, frogs that were fed a conspecific-based diet as tadpoles were more tolerant to the effect of parasite abundance on host mass during worm establishment. Overall, our study demonstrates that the diet of Cuban tree frog tadpoles affects the gut microbiota and defenses against

  10. Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    Dieni, Christopher A; Storey, Kenneth B

    2008-04-22

    The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65-70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to approximately 1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg.ATP and Mg.ADP and inhibited by Mg.GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5 degrees C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

  11. Food Habits of the Endemic Long Legged Wood Frog, Rana Pseudodalmatina (Amphibia, Ranidae, in Northern Iran

    Directory of Open Access Journals (Sweden)

    Najibzadeh M.

    2016-08-01

    Full Text Available Iranian long legged wood frog, Rana pseudodalmatina Eiselt & Schmidtler, 1971 is a brown frog species endemic to the Hyrcanian forest. The objective of the present study is to collect detailed information on the feeding habits of 44 specimens of this species (24 ♂, 20 ♀ by analyzing the stomach contents of individuals from 10 populations inhabiting range. The food habit of R. pseudodalmatina generally varies by the availability of surrounding prey items, and it is a foraging predator, the food of which consists largely of Coleoptera (mainly Carabidae, Dytiscidae and Haliplidae, Diptera (Muscidae and Hymenoptera (Formicidae, and no difference was found between females and males in the stomach content.

  12. Helminth parasites of the levantine frog (Pelophylax bedriagae Camerano, 1882 from the western part of Turkey

    Directory of Open Access Journals (Sweden)

    Demır S.

    2015-02-01

    Full Text Available Fifty-four Pelophylax bedriagae (Levantine Frog from Turkey (İzmir and Manisa Provinces were examined for helminth parasites. The frogs were collected between 2012 and 2014 years. Eight species of helminth parasites were recorded: 3 species of Nematoda (Rhabdias bufonis, Cosmocerca ornata, Oswaldocruzia filiformis, 3 species of Digenea (Diplodiscus subclavatus, Haematoloechus bre-viansa, Gorgoderina vitelliloba, 1 species of Acanthocephala (Acanthocephalus ranae and 1 species of Hirudinea (Hirudo medicinalis. Pelophylax bedriagae is a new host record for these parasite species.

  13. Histamine H1 receptors are expressed in mouse and frog semicircular canal sensory epithelia.

    Science.gov (United States)

    Botta, Laura; Tritto, Simona; Perin, Paola; Laforenza, Umberto; Gastaldi, Giulia; Zampini, Valeria; Zucca, Gianpiero; Valli, Stefano; Masetto, Sergio; Valli, Paolo

    2008-03-05

    Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. Their site and mechanism of action, however, are still poorly understood. To increase our knowledge of the histaminergic system in the vestibular organs, we have investigated the expression of H1 and H3 histamine receptors in the frog and mouse semicircular canal sensory epithelia. Analysis was performed by mRNA reverse transcriptase-PCR, immunoblotting and immunocytochemistry experiments. Our data show that both frog and mouse vestibular epithelia express H1 receptors. Conversely no clear evidence for H3 receptors expression was found.

  14. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  15. A new Gephyromantis (Phylacomantis frog species from the pinnacle karst of Bemaraha, western Madagascar

    Directory of Open Access Journals (Sweden)

    Angelica Crottini

    2011-02-01

    Full Text Available We describe a new mantellid frog of the subfamily Mantellinae from the karstic Bemaraha Plateau, western Madagascar. The new species belongs to the genus Gephyromantis, subgenus Phylacomantis, which previously included G. azzurrae, G. corvus and G. pseudoasper. Gephyromantis atsingy sp. n. has a snout-vent length of 35–43 mm and is a scansorial frog living among the Tsingy de Bemaraha pinnacles and inside the caves present in the area. A morphological analysis and biomolecular comparison revealed the degree of differentiation between these four species of the Phylacomantis subgenus. The new species seems to be endemic to Tsingy de Bemaraha.

  16. Blood parasites of frogs from an equatorial African montane forest in western Uganda.

    Science.gov (United States)

    Readel, Anne M; Goldberg, Tony L

    2010-04-01

    In a survey of blood parasites in Ugandan frogs, 30 (17%) of 180 frogs were infected with at least 1 species of Hepatozoon or Trypanosoma, or with microfilariae. There were significant differences in the prevalence of parasitism among species, with parasitemia detected in only 3 of 9 species. The intensity of blood parasite infection ranged from 1 to 1,080 infected cells per 5,000 cells examined. Seasonal changes in the prevalence and intensity of parasitemia were not observed, nor was there any association between parasitemia and infection with the pandemic fungus Batrachochytrium dendrobatidis.

  17. Whale Heart

    DEFF Research Database (Denmark)

    2017-01-01

    Student bachelor film. Synopsis:Silas lives in an isolated whaling town, toiling for months in the harsh and bloody trade on which he and his community depend. However, in order to be capable of killing the creatures whose bone and blubber pay his wage, he has developed an ungodly method for extr...

  18. Cost-effective conservation of an endangered frog under uncertainty.

    Science.gov (United States)

    Rose, Lucy E; Heard, Geoffrey W; Chee, Yung En; Wintle, Brendan A

    2016-04-01

    How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well-developed tools exist for prioritizing areas for one-time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost-effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost-effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost-effectiveness analysis. This allowed us to discern between cost-effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost-effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost-effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost-effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost

  19. Heart failure - surgeries and devices

    Science.gov (United States)

    ... surgery; HF - surgery; Intra-aortic balloon pumps - heart failure; IABP - heart failure; Catheter based assist devices - heart failure ... problem may cause heart failure or make heart failure worse. Heart valve surgery may be needed to repair or ...

  20. [Atrial fibrillation concomitant with valvular heart disease].

    Science.gov (United States)

    Ishii, Yosuke

    2013-01-01

    Patients with valvular heart disease frequently have atrial fibrillation(AF) due to elevated pressure and dilatation of the left and right atria and pulmonary veins. Guidelines for valvular heart disease and AF recommend that surgical treatment for the valvular heart disease should be performed concomitantly with AF surgery. The Full-Maze procedure has evolved into the gold standard of treatment for medically refractory AF. In addition to the pulmonary vein isolation, the right and left atrial incisions of the Full-Maze procedure are designed to block potential macroreentrant pathways. According to the mechanisms of AF with valvular heart disease, the Full-Maze procedure is more effective for the patients than the pulmonary vein isolation alone.

  1. Valvular Heart Disease in Heart Failure

    Directory of Open Access Journals (Sweden)

    Giuseppe MC Rosano

    2017-01-01

    Full Text Available Structural valvular heart disease may be the cause of heart failure or may worsen the clinical status of patients with heart failure. Heart failure may also develop in patients treated with valve surgery. Patients with heart failure with valvular heart disease are at increased risk of events including sudden cardiac death. Before considering intervention (surgical or percutaneous all patients should receive appropriate medical and device therapy taking into account that vasodilators must be used with caution in patients with severe aortic stenosis. Numerous percutaneous and/or hybrid procedures have been introduced in the past few years and they are changing the management of valvular heart disease. In patients with heart failure and valvular heart disease, either primary or functional, the whole process of decision-making should be staged through a comprehensive evaluation of the risk– benefit ratio of different treatment strategies and should be made by a multidisciplinary ‘heart team’ with a particular expertise in valvular heart disease. The heart team should include heart failure cardiologists, cardiac surgeons/structural valve interventionists, imaging specialists, anaesthetists, geriatricians and intensive care specialists. This article will review recent developments and distill practical guidance in the management of this important heart failure co-morbidity.

  2. Differentiation of frog fats from vegetable and marine oils by Fourier Transform Infrared Spectroscopy and chemometric analysis

    Directory of Open Access Journals (Sweden)

    A. N. Nina Naquiah

    2015-01-01

    Full Text Available The agro-based production and consumption of frogs coupled with world-wide trading have been increased in the recent years giving rise to the risk of frog fat adulteration in expensive vegetable and marine oils. For the first time, we profiled here frog fats using Fourier Transform Infrared (FTIR Spectroscopy coupled with multivariate principal component analysis (PCA. The comparison of the FTIR spectral absorbance intensities demonstrated linkage of frog fats to other edible fats and oils. Three commercially available marine oils and three vegetables oils were studied with frog fats and clear pattern of clusters with distinctive identifiable features were obtained through PCA modeling. PCA analysis identified 2922.21 cm-1, 2852.88 cm-1, 1745.45 cm-1, 1158.29 cm-1 and 721.51 cm-1 FTIR-frequencies as the most discriminating variables influencing the group separation into different clusters. This fundamental study has clear implications in the identification of frog fat from its marine and vegetable counterparts for the potential detection of frog fat adulteration in various fat and oils.

  3. Dry-season retreat and dietary shift of the dart-poison frog Dendrobates tinctorius (Anura: Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Marga Born

    2010-07-01

    Full Text Available Seasonal rainfall affects tropical forest dynamics and behaviorof species that are part of these ecosystems. The positive correlation between amphibian activity patterns and rainfall has been demonstrated repeatedly. Members of Dendrobatidae, a clade of Neotropical dart-poison frogs, are well known for their habitat use and behavior during the rainy season, but their behavior during the dry season has received little attention. We studied habitat use and diet of the dendrobatid frog Dendrobates tinctorius in French Guiana during the rainy and dry seasons. Unlike many other dendrobatid frogs, D. tinctorius does not maintain territories for the entire rainy season. Both sexes colonize recently formed canopy-gaps and stay in these forest patches for only a few weeks. The frogs inthese patches consume a great diversity of prey, consisting of ants, beetles, wasps, insect larvae, and mites. During the dry season, frogs move to retreat sites in mature forest, such as palm bracts and tree holes. The frogs are less active and consume fewer prey items in the dry season, and they consume fewer wasps and insect larvae, but more termites. Ants are the most common prey items during both the wet and dry seasons. We discuss the effects of shifts in seasonal habitat use on the territorial behavior of dendrobatid frogs.

  4. Medicinal use of secretions (“the frog vaccine” from the kambô frog (Phyllomedusa bicolor by non-indigenous peoples in Rondônia, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Bernarde

    2009-09-01

    Full Text Available Amphibians have pharmaceutically active skin secretions that protect against infections and predation. Some indigenous people in southwestern Amazonia use these secretions from P. bicolor for medicinal purposes. While the use of these secretions by indigenous people is relatively well-known, the use by non-indigenous peoples is very poorly studied. Here we describe the use of the “frog vaccine” by non-indigenous populations in the Brazilian state of Rondônia. Thirty-one people who had received this “vaccine” were interviewed. The use of this vaccine is not typical or habitual in this region, and the person who administers the vaccine must travel from another part of Amazonia. Users of the vaccine come from middle and upper social classes with reasonable levels of education (primary, secondary and university. Approximately half the people vaccinated felt that their health had improved after vaccination and if need be, they would take the vaccination again. Most of the people do not know the frog species from which the secretions are taken. While the people who use this treatment believe that it is good for any infirmity, the medicinal properties, if any, of the “frog vaccine” are under study and are still unknown.

  5. Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

    Science.gov (United States)

    Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

    2015-01-01

    In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

  6. The Semantics of Heart: Translation Problems

    Directory of Open Access Journals (Sweden)

    Hortensia Pârlog

    2005-06-01

    Full Text Available Words hardly ever occur on their own, because they can hardly mean anything on their own, when asked about the meaning of an isolated word, in order to figure it out, what one does is try to place it in a context or use it in a collocation. The verbal contexts in which words appear influence or at least clarify their semantic value, it is because of contextual factors that a word may have more than one meaning. Therefore, the analysis above word level is extremely important. An analysis of translational decisions may also prove to be a valuable source of information in establishing the semantics of a lexical item. The above statements are illustrated by discussing the semantics of heart. The word occurs in a great number of structures in both English and Romanian, of which eight will be analysed: heart + verb, verb + heart, heart + of phrase, adjective + heart, heart + head noun, head noun +of heart, adjective + preposition + heart, heart in sayings or fixed expressions.

  7. Description of the tadpoles of three rare species of megophryid frogs (Amphibia: Anura: Megophryidae) from Gunung Mulu, Sarawak, Malaysia.

    Science.gov (United States)

    Oberhummer, Evelyne; Barten, Catherin; Schweizer, Manuel; Das, Indraneil; Haas, Alexander; Hertwig, Stefan T

    2014-07-09

    The megophryid frogs Leptobrachella brevicrus, Leptolalax dringi and Megophrys dringi are species exclusively known  from highly localised areas in isolated mountain ranges on Borneo. The tadpoles and adults in this study were collected at the shared type locality for the three species in Gunung Mulu National Park, Sarawak, Malaysia (Borneo). The species identities of larvae were determined via comparison to syntopic adults using DNA barcoding techniques based on partial 16S rRNA mitochondrial gene sequences. The genetic data supported the status of the three taxa as valid species. Descriptions of colouration in life and after preservation, external morphological features, morphometric measurements and ecological notes in comparison to congeneric species are supplied. The tadpoles of L. brevicrus and L. dringi show similar adaptations to a fossorial lifestyle. These include an elongated, vermiform body, a relatively long tail and small eyes. Both were found in the gravel beds of a small mountain stream. In contrast, the larvae of M. dringi are adapted to occupying and feeding at the surface of pools within the stream. 

  8. Identification of a Novel Vasodilatory Octapeptide from the Skin Secretion of the African Hyperoliid Frog, Kassina senegalensis.

    Science.gov (United States)

    Du, Qiang; Wang, Hui; Ma, Chengbang; Wu, Yue; Xi, Xinping; Zhou, Mei; Chen, Tianbao; Shaw, Chris; Wang, Lei

    2017-07-19

    The defensive skin secretions of amphibians continue to be an excellent source of novel biologically-active peptides. Here we report the identification and pharmacological activity of a novel C-terminally amided myotropic octapeptide from the skin secretion of the African hyperoliid frog, Kassina senegalensis . The 8-amino acid peptide has the following primary structure: WMSLGWSL-amide and has a molecular mass of 978 Da. The primary structure and organisation of the biosynthetic precursor of WL-8 amide was successfully deduced from cloned skin secretion-derived cDNA. The open-reading frame encoded a single copy of WL-8, located at the C-terminus. Synthetic WL-8 amide was found to cause relaxation of rat tail artery smooth muscle with an EC 50 of 25.98 nM. This peptide is unique in terms of its primary structure and is unlike any other peptide previously isolated from an amphibian source which has been archived in the NCBI database. WL-8 amide thus represents the prototype of a novel family of myotropic peptide from amphibian defensive skin secretions.

  9. Conduction velocity of action potentials measured from unidimensional latency-topography in human and frog skeletal muscle fibers.

    Science.gov (United States)

    Homma, S; Nakajima, Y; Hayashi, K; Toma, S

    1986-01-01

    Conduction of an action potential along skeletal muscle fibers was graphically displayed by unidimensional latency-topography, UDLT. Since the slopes of the equipotential line were linear and the width of the line was constant, it was possible to calculate conduction velocity from the slope. To determine conduction direction of the muscle action potential elicited by electric stimulation applied directly to the muscle, surface recording electrodes were placed on a two-dimensional plane over a human muscle. Thus a bi-dimensional topography was obtained. Then, twelve or sixteen surface electrodes were placed linearly along the longitudinal direction of the action potential conduction which was disclosed by the bi-dimensional topography. Thus conduction velocity of muscle action potential in man, calculated from the slope, was for m. brachioradialis, 3.9 +/- 0.4 m/s; for m. biceps brachii, 3.6 +/- 0.2 m/s; for m. sternocleidomastoideus, 3.6 +/- 0.4 m/s. By using a tungsten microelectrode to stimulate the motor axons, a convex-like equipotential line of an action potential in UDLT was obtained from human muscle fibers. Since a similar pattern of UDLT was obtained from experiments on isolated frog muscles, in which the muscle action potential was elicited by stimulating the motor axon, it was assumed that the maximum of the curve corresponds to the end-plate region, and that the slopes on both sides indicate bi-directional conduction of the action potential.

  10. Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

    Science.gov (United States)

    Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

    2017-09-01

    Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

  11. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  12. Modeling Sexual Selection in Túngara Frog and Rationality of Mate Choice.

    Science.gov (United States)

    Vargas Bernal, Esteban; Sanabria Malagon, Camilo

    2017-12-01

    The males of the species of frogs Engystomops pustulosus produce simple and complex calls to lure females, as a way of intersexual selection. Complex calls lead males to a greater reproductive success than what simple calls do. However, the complex calls are also more attractive to their main predator, the bat Trachops cirrhosus. Therefore, as M. Ryan suggests in (The túngara frog: a study in sexual selection and communication. University of Chicago Press, Chicago, 1985), the complexity of the calls lets the frogs keep a trade-off between reproductive success and predation. In this paper, we verify this trade-off from the perspective of game theory. We first model the proportion of simple calls as a symmetric game of two strategies. We also model the effect of adding a third strategy, males that keep quiet and intercept females, which would play a role of intrasexual selection. Under the assumption that the decision of the males takes into account this trade-off between reproductive success and predation, our model reproduces the observed behavior reported in the literature with minimal assumption on the parameters. From the model with three strategies, we verify that the quiet strategy could only coexists with the simple and complex strategies if the rate at which quiet males intercept females is high, which explains the rarity of the quiet strategy. We conclude that the reproductive strategy of the male frog E. pustulosus is rational.

  13. COMPARATIVE ACTIVITY OF CECROPIN A AND POLYMYXIN B AGAINST FROG BACTERIAL PATHOGENS

    Directory of Open Access Journals (Sweden)

    Ermin Schadich

    2013-03-01

    Full Text Available The antimicrobial activity of two antimicrobial peptides, cecropin A and polymyxin B against different bacterial pathogens associated with bacterial dermatosepticemia, a fatal bacterial infectious disease of frogs was investigated. The peptides were tested in serial of concentrations (100-0.19 µg/ml for growth inhibition of seven pathogens: Aeromonas hydrophila, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Serratia liquefaciens. Their antimicrobial activity was compared with that of two antimicrobial peptides from frog skin, magainin 2 and aurein 2.1. Both cecropin A and polymyxin B, completely inhibited the growth of three pathogens: C. freundii, K. pneumoniae and P. aeruginosa at a concentration some sixteen times less than two skin peptides. Furthermore, cecropin A inhibited the growth of three pathogens resistant to the two skin peptides, A. hydrophila, C. meningosepticum and P. mirabilis. Polymyxin B also inhibited the growth of three pathogens resistant to the skin peptides, A. hydrophila, C. meningosepticum and S. liquefaciens. Cecropin A and polymyxin B have marked antibacterial activity against different frog bacterial pathogens indicating potential for therapeutic measures.Keywords: frogs, antimicrobial, bacteria, cecropin, polymyxin, resistance

  14. Chytrid Fungus, Batrachochytrium dendrobatidis , in Wild Populations of the Lake Titicaca Frog, Telmatobius culeus, in Peru.

    Science.gov (United States)

    Berenguel, Raul A; Elias, Roberto K; Weaver, Thomas J; Reading, Richard P

    2016-10-01

    The Lake Titicaca frog (Telmatobius culeus) is critically endangered, primarily from overexploitation. However, additional threats, such as chytrid fungus ( Batrachochytrium dendrobatidis ), are poorly studied. We found moderate levels of chytrid infection using quantitative PCR. Our results enhance our understanding of chytrid tolerance to high pH and low water temperature.

  15. A taxonomic revision of the Neotropical poison frog genus Ranitomeya (Amphibia: Dendrobatidae)

    NARCIS (Netherlands)

    Brown, J.L.; Twomey, E.; Amézquita, A.; Souza, M.B.; Caldwell, J.P.; Lötters, S.; May, R.; Melo-Sampaio, P.R.; Mejía-Vargas, D.; Perez-Peña, P.; Pepper, M.; Poelman, E.H.; Sanchez-Rodriguez, M.; Summers, K.

    2011-01-01

    The Neotropical poison frog genus Ranitomeya is revised, resulting in one new genus, one new species, five synonymies and one species classified as nomen dubium. We present an expanded molecular phylogeny that contains 235 terminals, 104 of which are new to this study. Notable additions to this

  16. On Semiotics and Jumping Frogs: The Role of Gesture in the Teaching of Subtraction

    Science.gov (United States)

    Farrugia, Marie Therese

    2017-01-01

    In this article, I describe a research/teaching experience I undertook with a class of 5-year-old children in Malta. The topic was subtraction on the number line. I interpret the teaching/learning process through a semiotic perspective. In particular, I highlight the role played by the gesture of forming "frog jumps" on the number line.…

  17. Fatal attraction: adaptations to prey on native frogs imperil snakes after invasion of toxic toads.

    Science.gov (United States)

    Hagman, Mattias; Phillips, Benjamin L; Shine, Richard

    2009-08-07

    Adaptations that enhance fitness in one situation can become liabilities if circumstances change. In tropical Australia, native snake species are vulnerable to the invasion of toxic cane toads. Death adders (Acanthophis praelongus) are ambush foragers that (i) attract vertebrate prey by caudal luring and (ii) handle anuran prey by killing the frog then waiting until the frog's chemical defences degrade before ingesting it. These tactics render death adders vulnerable to toxic cane toads (Bufo marinus), because toads elicit caudal luring more effectively than do native frogs, and are more readily attracted to the lure. Moreover, the strategy of delaying ingestion of a toad after the strike does not prevent fatal poisoning, because toad toxins (unlike those of native frogs) do not degrade shortly after the prey dies. In our laboratory and field trials, half of the death adders died after ingesting a toad, showing that the specialized predatory behaviours death adders use to capture and process prey render them vulnerable to this novel prey type. The toads' strong response to caudal luring also renders them less fit than native anurans (which largely ignored the lure): all toads bitten by adders died. Together, these results illustrate the dissonance in behavioural adaptations that can arise following the arrival of invasive species, and reveal the strong selection that occurs when mutually naive species first interact.

  18. Long-Term United Kindrom Trends in the Breeding Phenology of the Common Frog, Rana temporaria

    Czech Academy of Sciences Publication Activity Database

    Scott, W.A.; Pithart, David; Adamson, J. K.

    2008-01-01

    Roč. 42, č. 1 (2008), s. 89-96 ISSN 0022-1511 Institutional research plan: CEZ:AV0Z60870520 Keywords : Long-term * Common Frog * Breeding * Rana temporaria Subject RIV: EG - Zoology Impact factor: 0.888, year: 2008

  19. 78 FR 53581 - Endangered and Threatened Wildlife and Plants; Threatened Status for Oregon Spotted Frog

    Science.gov (United States)

    2013-08-29

    ...). Oregon spotted frogs breed in shallow pools (2-12 in (5-30 cm) deep) that are near flowing water, or... to: Public Comments Processing, Attn: FWS-R1-ES-2013-0013; Division of Policy and Directives... Friesz 1998, p. 3). They are laid in shallow, often temporary, pools of water; gradually receding...

  20. Mimetic Divergence and the Speciation Continuum in the Mimic Poison Frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Venegas, Pablo J.

    2016-01-01

    While divergent ecological adaptation can drive speciation, understanding the factors that facilitate or constrain this process remains a major goal in speciation research. Here, we study two mimetic transition zones in the poison frog Ranitomeya imitator, a species that has undergone a Mullerian...