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Sample records for asexual blood stage

  1. Mechanisms of immune protection in the asexual blood stage infection by Plasmodium falciparum: analysis by in vitro and ex-vivo assays

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    Jurg Gysin

    1992-01-01

    Full Text Available Mechanisms of immune protection against the asexual blood stage infection by Plasmodium falciparum are reviewed. Recent studies of two independent lines of research developed at the Institute Pasteur, in humans and primate infections clearly indicate an obligatory interaction of antibodies and effector cells to express the anti-parasitic effect.

  2. Mechanisms of protective immunity against asexual blood stages of Plasmodium falciparum in the experimental host Saimiri

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    J. Gysin

    1992-01-01

    Full Text Available In the Saimiri monkey, an experimental host for human malaria, acquired protection against Plasmodium falciparum blood stages depends on the IgG antibody populations developed. In vivo protective anti-falciparum activity of IgG antibodies is correlated with the in vivo opsonizing activity promoting phagocytosis of parasited red bloood cells. In contrast, non protective antibodies inhibit this mechanism by competing at the target level. A similar phenomenon can be and human infection. Anti-cytoadherent and anti-rosette antibodies developed by Saimiri and humans prevent the development of physiopathological events like cerebral malaria which can also occur in this experimental host. Furthermore, transfer to protective human anti-falciparum IgG antibodies into infected Saimiri monkeys exerts an anti parasite activity as efficient as that observed when it is transfered into acute falciparum malaria patients, making the Saimiri an even more attractive host. Studies on the role of immunocompetent cells in the protective immune reponse are still in their infancy, however the existance of a restricted polymorphism of MHC II class molecules in the Saimiri confers additional theoretical and practical importance to this model.

  3. Flow cytometric readout based on Mitotracker Red CMXRos staining of live asexual blood stage malarial parasites reliably assesses antibody dependent cellular inhibition

    DEFF Research Database (Denmark)

    Jogdand, Prajakta S; Singh, Susheel K; Christiansen, Michael;

    2012-01-01

    ABSTRACT: BACKGROUND: Functional in vitro assays could provide insights into the efficacy of malaria vaccine candidates. For estimating the anti-parasite effect induced by a vaccine candidate, an accurate determination of live parasite count is an essential component of most in vitro bioassays...... asynchronous and tightly synchronized asexual blood stage cultures of Plasmodium falciparum were stained with CMXRos and subjected to detection by flow cytometry and fluorescence microscopy. The parasite counts obtained by flow cytometry were compared to standard microscopic counts obtained through examination...

  4. Plasmodium falciparum SERA5 plays a non-enzymatic role in the malarial asexual blood-stage lifecycle.

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    Stallmach, Robert; Kavishwar, Manoli; Withers-Martinez, Chrislaine; Hackett, Fiona; Collins, Christine R; Howell, Steven A; Yeoh, Sharon; Knuepfer, Ellen; Atid, Avshalom J; Holder, Anthony A; Blackman, Michael J

    2015-04-01

    The malaria parasite Plasmodium falciparum replicates in an intraerythrocytic parasitophorous vacuole (PV). The most abundant P. falciparum PV protein, called SERA5, is essential in blood stages and possesses a papain-like domain, prompting speculation that it functions as a proteolytic enzyme. Unusually however, SERA5 possesses a Ser residue (Ser596) at the position of the canonical catalytic Cys of papain-like proteases, and the function of SERA5 or whether it performs an enzymatic role is unknown. In this study, we failed to detect proteolytic activity associated with the Ser596-containing parasite-derived or recombinant protein. However, substitution of Ser596 with a Cys residue produced an active recombinant enzyme with characteristics of a cysteine protease, demonstrating that SERA5 can bind peptides. Using targeted homologous recombination in P. falciparum, we substituted Ser596 with Ala with no phenotypic consequences, proving that SERA5 does not perform an essential enzymatic role in the parasite. We could also replace an internal segment of SERA5 with an affinity-purification tag. In contrast, using almost identical targeting constructs, we could not truncate or C-terminally tag the SERA5 gene, or replace Ser596 with a bulky Arg residue. Our findings show that SERA5 plays an indispensable but non-enzymatic role in the P. falciparum blood-stage life cycle.

  5. Flow cytometric readout based on Mitotracker Red CMXRos staining of live asexual blood stage malarial parasites reliably assesses antibody dependent cellular inhibition

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    Jogdand Prajakta S

    2012-07-01

    Full Text Available Abstract Background Functional in vitro assays could provide insights into the efficacy of malaria vaccine candidates. For estimating the anti-parasite effect induced by a vaccine candidate, an accurate determination of live parasite count is an essential component of most in vitro bioassays. Although traditionally parasites are counted microscopically, a faster, more accurate and less subjective method for counting parasites is desirable. In this study mitochondrial dye (Mitotracker Red CMXRos was used for obtaining reliable live parasite counts through flow cytometry. Methods Both asynchronous and tightly synchronized asexual blood stage cultures of Plasmodium falciparum were stained with CMXRos and subjected to detection by flow cytometry and fluorescence microscopy. The parasite counts obtained by flow cytometry were compared to standard microscopic counts obtained through examination of Giemsa-stained thin smears. A comparison of the ability of CMXRos to stain live and compromised parasites (induced by either medium starvation or by anti-malarial drug treatment was carried out. Finally, parasite counts obtained by CMXRos staining through flow cytometry were used to determine specific growth inhibition index (SGI in an antibody-dependent cellular inhibition (ADCI assay. Results Mitotracker Red CMXRos can reliably detect live intra-erythrocytic stages of P. falciparum. Comparison between staining of live with compromised parasites shows that CMXRos predominantly stains live parasites with functional mitochondria. Parasite counts obtained by CMXRos staining and flow cytometry were highly reproducible and can reliably determine the ability of IgG from hyper-immune individuals to inhibit parasite growth in presence of monocytes in ADCI assay. Further, a dose-dependent parasite growth inhibitory effect could be detected for both total IgG purified from hyper-immune sera and affinity purified IgGs against the N-terminal non-repeat region of GLURP

  6. CRISPR-Cas9-modified pfmdr1 protects Plasmodium falciparum asexual blood stages and gametocytes against a class of piperazine-containing compounds but potentiates artemisinin-based combination therapy partner drugs.

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    Ng, Caroline L; Siciliano, Giulia; Lee, Marcus C S; de Almeida, Mariana J; Corey, Victoria C; Bopp, Selina E; Bertuccini, Lucia; Wittlin, Sergio; Kasdin, Rachel G; Le Bihan, Amélie; Clozel, Martine; Winzeler, Elizabeth A; Alano, Pietro; Fidock, David A

    2016-08-01

    Emerging resistance to first-line antimalarial combination therapies threatens malaria treatment and the global elimination campaign. Improved therapeutic strategies are required to protect existing drugs and enhance treatment efficacy. We report that the piperazine-containing compound ACT-451840 exhibits single-digit nanomolar inhibition of the Plasmodium falciparum asexual blood stages and transmissible gametocyte forms. Genome sequence analyses of in vitro-derived ACT-451840-resistant parasites revealed single nucleotide polymorphisms in pfmdr1, which encodes a digestive vacuole membrane-bound ATP-binding cassette transporter known to alter P. falciparum susceptibility to multiple first-line antimalarials. CRISPR-Cas9 based gene editing confirmed that PfMDR1 point mutations mediated ACT-451840 resistance. Resistant parasites demonstrated increased susceptibility to the clinical drugs lumefantrine, mefloquine, quinine and amodiaquine. Stage V gametocytes harboring Cas9-introduced pfmdr1 mutations also acquired ACT-451840 resistance. These findings reveal that PfMDR1 mutations can impart resistance to compounds active against asexual blood stages and mature gametocytes. Exploiting PfMDR1 resistance mechanisms provides new opportunities for developing disease-relieving and transmission-blocking antimalarials.

  7. Amino acid efflux by asexual blood-stage Plasmodium falciparum and its utility in interrogating the kinetics of hemoglobin endocytosis and catabolism in vivo.

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    Dalal, Seema; Klemba, Michael

    2015-06-01

    The endocytosis and catabolism of large quantities of host cell hemoglobin is a hallmark of the intraerythrocytic asexual stage of the human malaria parasite Plasmodium falciparum. It is known that the parasite's production of amino acids from hemoglobin far exceeds its metabolic needs. Here, we show that P. falciparum effluxes large quantities of certain non-polar (Ala, Leu, Val, Pro, Phe, Gly) and polar (Ser, Thr, His) amino acids to the external medium. That these amino acids originate from hemoglobin catabolism is indicated by the strong correlation between individual amino acid efflux rates and their abundances in hemoglobin, and the ability of the food vacuole falcipain inhibitor E-64d to greatly suppress efflux rates. We then developed a rapid, sensitive and precise method for quantifying flux through the hemoglobin endocytic-catabolic pathway that is based on leucine efflux. Optimization of the method involved the generation of a novel amino acid-restricted RPMI formulation as well as the validation of D-norvaline as an internal standard. The utility of this method was demonstrated by characterizing the effects of the phosphatidylinositol-3-kinase inhibitors wortmannin and dihydroartemisinin on the kinetics of Leu efflux. Both compounds rapidly inhibited Leu efflux, which is consistent with a role for phosphtidylinositol-3-phosphate production in the delivery of hemoglobin to the food vacuole; however, wortmannin inhibition was transient, which was likely due to the instability of this compound in culture medium. The simplicity, convenience and non-invasive nature of the Leu efflux assay described here makes it ideal for characterizing the in vivo kinetics of hemoglobin endocytosis and catabolism, for inhibitor target validation studies, and for medium-throughput screens to identify novel inhibitors of cytostomal endocytosis.

  8. Phase 1 Trial of AMA1-C1/Alhydrogel plus CPG 7909: An Asexual Blood-Stage Vaccine for Plasmodium falciparum Malaria

    OpenAIRE

    Mullen, Gregory E. D.; Ellis, Ruth D; Kazutoyo Miura; Elissa Malkin; Caroline Nolan; Mhorag Hay; Michael P Fay; Allan Saul; Daming Zhu; Kelly Rausch; Samuel Moretz; Hong Zhou; Long, Carole A.; Miller, Louis H.; John Treanor

    2008-01-01

    BACKGROUND: Apical Membrane Antigen 1 (AMA1), a polymorphic merozoite surface protein, is a leading blood-stage malaria vaccine candidate. This is the first reported use in humans of an investigational vaccine, AMA1-C1/Alhydrogel, with the novel adjuvant CPG 7909. METHODS: A phase 1 trial was conducted at the University of Rochester with 75 malaria-naive volunteers to assess the safety and immunogenicity of the AMA1-C1/Alhydrogel+CPG 7909 malaria vaccine. Participants were sequentially enroll...

  9. Phase 1 trial of AMA1-C1/Alhydrogel plus CPG 7909: an asexual blood-stage vaccine for Plasmodium falciparum malaria.

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    Gregory E D Mullen

    Full Text Available BACKGROUND: Apical Membrane Antigen 1 (AMA1, a polymorphic merozoite surface protein, is a leading blood-stage malaria vaccine candidate. This is the first reported use in humans of an investigational vaccine, AMA1-C1/Alhydrogel, with the novel adjuvant CPG 7909. METHODS: A phase 1 trial was conducted at the University of Rochester with 75 malaria-naive volunteers to assess the safety and immunogenicity of the AMA1-C1/Alhydrogel+CPG 7909 malaria vaccine. Participants were sequentially enrolled and randomized within dose escalating cohorts to receive three vaccinations on days 0, 28 and 56 of either 20 microg of AMA1-C1/Alhydrogel+564 microg CPG 7909 (n = 15, 80 microg of AMA1-C1/Alhydrogel (n = 30, or 80 microg of AMA1-C1/Alhydrogel+564 microg CPG 7909 (n = 30. RESULTS: Local and systemic adverse events were significantly more likely to be of higher severity with the addition of CPG 7909. Anti-AMA1 immunoglobulin G (IgG were detected by enzyme-linked immunosorbent assay (ELISA, and the immune sera of volunteers that received 20 microg or 80 microg of AMA1-C1/Alhydrogel+CPG 7909 had up to 14 fold significant increases in anti-AMA1 antibody concentration compared to 80 microg of AMA1-C1/Alhydrogel alone. The addition of CPG 7909 to the AMA1-C1/Alhydrogel vaccine in humans also elicited AMA1 specific immune IgG that significantly and dramatically increased the in vitro growth inhibition of homologous parasites to levels as high as 96% inhibition. CONCLUSION/SIGNIFICANCE: The safety profile of the AMA1-C1/Alhydrogel+CPG 7909 malaria vaccine is acceptable, given the significant increase in immunogenicity observed. Further clinical development is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov NCT00344539.

  10. Indomethacin induction of metamorphosis from the asexual stage to sexual stage in the moon jellyfish, Aurelia aurita.

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    Kuniyoshi, Hisato; Okumura, Izumi; Kuroda, Rie; Tsujita, Natsumi; Arakawa, Kenji; Shoji, Jun; Saito, Tamio; Osada, Hiroyuki

    2012-01-01

    We found while screening a chemical library that indomethacin, an inhibitor of prostaglandin biosynthesis, induced strobilation (metamorphosis from the asexual to sexual stage) in the moon jellyfish, Aurelia aurita. Indomethacin initiated strobilation in a dose-dependent manner, but was not involved in the progression of strobilation. Pharmacological experiments suggested that indomethacin could induce strobilation independently of prostaglandin biosynthesis.

  11. Does an asexual endophyte symbiont alter life stage and long-term survival in a perennial host grass?

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    Faeth, Stanley H; Hamilton, Cyd E

    2006-11-01

    Asexual, seedborne endophytic fungi in perennial grasses are often viewed as strong mutualists because fitness of the symbiont and host grass are closely coupled. However, at least for some native grasses, the asexual endophyte, Neotyphodium, acts parasitically, yet remains at high frequencies in natural populations. Most previous studies of Neotyphodium effects on host survival have been short term relative to the long life span of the perennial grass host. We therefore tested the hypothesis that Neotyphodium alters the survival in various life stages and long-term survival of adult native Arizona fescue (Festuca arizonica). To test the former, we planted 40 infected (E+) and 40 uninfected (E-, endophyte removed) seeds from four different maternal plants in the field under ambient conditions. We followed survival of seeds, seedlings, and adult plants over a 5-year period. To test the latter, we determined the infection of 1633 adult plants and followed their survival over the next 5-7 years. E+ seeds did not differ from uninfected seeds in terms of overall survival from seed germination to seedling to adult. However, the shape of the survival curve differed, with E+ plants showing higher mortality in early life stages. E+ adult plants did not differ from E- plants in long-term survival. Survival was generally very high during the study, which included a severe and prolonged drought. Infection by asexual Neotyphodium does not increase survival in early life stages or that of adult plants. Because asexual, vertically transmitted symbionts are predicted by evolutionary theory to be strong mutualists, the persistence of high infection frequencies in natural populations without long-term benefits to the host remains enigmatic. One possible explanation is that the long life span of the perennial host and low seedling recruitment may obscure either the costs or benefits of endophyte infection.

  12. A multi-stage malaria vaccine candidate targeting both transmission and asexual parasite life-cycle stages

    DEFF Research Database (Denmark)

    Theisen, Michael; Roeffen, Will; Singh, Susheel K;

    2014-01-01

    Effective control and eventual eradication of malaria drives the imperative need for clinical development of a malaria vaccine. Asexual parasite forms are responsible for clinical disease and death while apathogenic gametocytes are responsible for transmission from man to mosquito. Vaccines...

  13. Evolution and architecture of the inner membrane complex in asexual and sexual stages of the malaria parasite.

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    Kono, Maya; Herrmann, Susann; Loughran, Noeleen B; Cabrera, Ana; Engelberg, Klemens; Lehmann, Christine; Sinha, Dipto; Prinz, Boris; Ruch, Ulrike; Heussler, Volker; Spielmann, Tobias; Parkinson, John; Gilberger, Tim W

    2012-09-01

    The inner membrane complex (IMC) is a unifying morphological feature of all alveolate organisms. It consists of flattened vesicles underlying the plasma membrane and is interconnected with the cytoskeleton. Depending on the ecological niche of the organisms, the function of the IMC ranges from a fundamental role as reinforcement system to more specialized roles in motility and cytokinesis. In this article, we present a comprehensive evolutionary analysis of IMC components, which exemplifies the adaptive nature of the IMCs' protein composition. Focusing on eight structurally distinct proteins in the most prominent "genus" of the Alveolata-the malaria parasite Plasmodium-we demonstrate that the level of conservation is reflected in phenotypic characteristics, accentuated in differential spatial-temporal patterns of these proteins in the motile stages of the parasite's life cycle. Colocalization studies with the centromere and the spindle apparatus reveal their discriminative biogenesis. We also reveal that the IMC is an essential structural compartment for the development of the sexual stages of Plasmodium, as it seems to drive the morphological changes of the parasite during the long and multistaged process of sexual differentiation. We further found a Plasmodium-specific IMC membrane matrix protein that highlights transversal structures in gametocytes, which could represent a genus-specific structural innovation required by Plasmodium. We conclude that the IMC has an additional role during sexual development supporting morphogenesis of the cell, which in addition to its functions in the asexual stages highlights the multifunctional nature of the IMC in the Plasmodium life cycle.

  14. A Puf RNA-binding protein encoding gene PlM90 regulates the sexual and asexual life stages of the litchi downy blight pathogen Peronophythora litchii.

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    Jiang, Liqun; Ye, Wenwu; Situ, Junjian; Chen, Yubin; Yang, Xinyu; Kong, Guanghui; Liu, Yaya; Tinashe, Runyanga J; Xi, Pinggen; Wang, Yuanchao; Jiang, Zide

    2017-01-01

    Sexual and asexual reproduction are two key processes in the pathogenic cycle of many filamentous pathogens. However in Peronophythora litchii, the causal pathogen for the litchi downy blight disease, critical regulator(s) of sexual or asexual differentiation has not been elucidated. In this study, we cloned a gene named PlM90 from P. litchii, which encodes a putative Puf RNA-binding protein. We found that PlM90 was highly expressed during asexual development, and much higher than that during sexual development, while relatively lower during cyst germination and plant infection. By polyethylene glycol (PEG)-mediated protoplast transformation, we generated three PlM90-silenced transformants and found a severely impaired ability in sexual spore production and a delay in stages of zoospore release and encystment. However, the pathogenicity of P. litchii was not affected by PlM90-silencing. Therefore we conclude that PlM90 specifically regulates the sexual and asexual differentiation of P. litchii.

  15. Enhancement of neutrophil-mediated killing of Plasmodium falciparum asexual blood forms by fatty acids: importance of fatty acid structure.

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    Kumaratilake, L M; Ferrante, A; Robinson, B S; Jaeger, T; Poulos, A

    1997-10-01

    Effects of fatty acids on human neutrophil-mediated killing of Plasmodium falciparum asexual blood forms were investigated by using a quantitative radiometric assay. The results showed that the antiparasitic activity of neutrophils can be greatly increased (>threefold) by short-term treatment with fatty acids with 20 to 24 carbon atoms and at least three double bonds. In particular, the n-3 polyenoic fatty acids, eicosapentaenoic and docosahexaenoic acids, and the n-6 fatty acid, arachidonic acid, significantly enhanced neutrophil antiparasitic activity. This effect was >1.5-fold higher than that induced by an optical concentration of the known agonist cytokine tumor necrosis factor alpha (TNF-alpha). At suboptimal concentrations, the combination of arachidonic acid and TNF-alpha caused a synergistic increase in neutrophil-mediated parasite killing. The fatty acid-induced effect was independent of the availability of serum opsonins but dependent on the structure of the fatty acids. The length of the carbon chain, degree of unsaturation, and availability of a free carboxyl group were important determinants of fatty acid activity. The fatty acids which increased neutrophil-mediated killing primed the enhanced superoxide radical generation of neutrophils in response to P. falciparum as detected by chemiluminescence. Scavengers of oxygen radicals significantly reduced the fatty acid-enhanced parasite killing, but cyclooxygenase and lipoxygenase inhibitors had no effect. These findings have identified a new class of immunoenhancers that could be exploited to increase resistance against Plasmodium species.

  16. Antibody responses to a panel of Plasmodium falciparum malaria blood-stage antigens in relation to clinical disease outcome in Sudan

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    Iriemenam, Nnaemeka C; Khirelsied, Atif H; Nasr, Amre;

    2009-01-01

    Despite many intervention programmes aimed at curtailing the scourge, malaria remains a formidable problem of human health. Immunity to asexual blood-stage of Plasmodium falciparum malaria is thought to be associated with protective antibodies of certain immunoglobulin classes and subclasses. We ...

  17. Phosphorylated and Nonphosphorylated PfMAP2 Are Localized in the Nucleus, Dependent on the Stage of Plasmodium falciparum Asexual Maturation

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    Farah Aida Dahalan

    2016-01-01

    Full Text Available Plasmodium falciparum mitogen-activated protein (MAP kinases, a family of enzymes central to signal transduction processes including inflammatory responses, are a promising target for antimalarial drug development. Our study shows for the first time that the P. falciparum specific MAP kinase 2 (PfMAP2 is colocalized in the nucleus of all of the asexual erythrocytic stages of P. falciparum and is particularly elevated in its phosphorylated form. It was also discovered that PfMAP2 is expressed in its highest quantity during the early trophozoite (ring form stage and significantly reduced in the mature trophozoite and schizont stages. Although the phosphorylated form of the kinase is always more prevalent, its ratio relative to the nonphosphorylated form remained constant irrespective of the parasites’ developmental stage. We have also shown that the TSH motif specifically renders PfMAP2 genetically divergent from the other plasmodial MAP kinase activation sites using Neighbour Joining analysis. Furthermore, TSH motif-specific designed antibody is crucial in determining the location of the expression of the PfMAP2 protein. However, by using immunoelectron microscopy, PPfMAP2 were detected ubiquitously in the parasitized erythrocytes. In summary, PfMAP2 may play a far more important role than previously thought and is a worthy candidate for research as an antimalarial.

  18. Phosphorylated and Nonphosphorylated PfMAP2 Are Localized in the Nucleus, Dependent on the Stage of Plasmodium falciparum Asexual Maturation

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    Dahalan, Farah Aida; Sidek, Hasidah Mohd; Murtey, Mogana Das; Embi, Mohammed Noor; Ibrahim, Jamaiah; Fei Tieng, Lim; Zakaria, Nurul Aiezzah

    2016-01-01

    Plasmodium falciparum mitogen-activated protein (MAP) kinases, a family of enzymes central to signal transduction processes including inflammatory responses, are a promising target for antimalarial drug development. Our study shows for the first time that the P. falciparum specific MAP kinase 2 (PfMAP2) is colocalized in the nucleus of all of the asexual erythrocytic stages of P. falciparum and is particularly elevated in its phosphorylated form. It was also discovered that PfMAP2 is expressed in its highest quantity during the early trophozoite (ring form) stage and significantly reduced in the mature trophozoite and schizont stages. Although the phosphorylated form of the kinase is always more prevalent, its ratio relative to the nonphosphorylated form remained constant irrespective of the parasites' developmental stage. We have also shown that the TSH motif specifically renders PfMAP2 genetically divergent from the other plasmodial MAP kinase activation sites using Neighbour Joining analysis. Furthermore, TSH motif-specific designed antibody is crucial in determining the location of the expression of the PfMAP2 protein. However, by using immunoelectron microscopy, PPfMAP2 were detected ubiquitously in the parasitized erythrocytes. In summary, PfMAP2 may play a far more important role than previously thought and is a worthy candidate for research as an antimalarial. PMID:27525262

  19. The Novel Oomycide Oxathiapiprolin Inhibits All Stages in the Asexual Life Cycle of Pseudoperonospora cubensis - Causal Agent of Cucurbit Downy Mildew.

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    Yigal Cohen

    Full Text Available Oxathiapiprolin is a new oomycide (piperidinyl thiazole isoxazoline class discovered by DuPont which controls diseases caused by oomycete plant pathogens. It binds in the oxysterol-binding protein domain of Oomycetes. Growth chambers studies with detached leaves and potted plants showed remarkable activity of oxathiapiprolin against Pseudoperonospora cubensis in cucurbits. The compound affected all stages in the asexual life cycle of the pathogen. It inhibited zoospore release, cystospore germination, lesion formation, lesion expansion, sporangiophore development and sporangial production. When applied to the foliage as a preventive spray no lesions developed due to inhibition of zoospore release and cystospore germination, and when applied curatively, at one or two days after inoculation, small restricted lesions developed but no sporulation occurred. When applied later to mature lesions, sporulation was strongly inhibited. Oxathiapiprolin suppressed sporulation of P. cubensis in naturally-infected leaves. It exhibited trans-laminar activity, translocated acropetaly from older to younger leaves, and moved from the root system to the foliage. Seed coating was highly effective in protecting the developed cucumber plants against downy mildew. UV microscopy observations made with cucumber leaves infected with P. cubensis revealed that inhibition of mycelium growth and sporulation induced by oxathiapiprolin was associated with callose encasement of the haustoria.

  20. Protection from experimental cerebral malaria with a single dose of radiation-attenuated, blood-stage Plasmodium berghei parasites.

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    Noel J Gerald

    Full Text Available BACKGROUND: Whole malaria parasites are highly effective in inducing immunity against malaria. Due to the limited success of subunit based vaccines in clinical studies, there has been a renewed interest in whole parasite-based malaria vaccines. Apart from attenuated sporozoites, there have also been efforts to use live asexual stage parasites as vaccine immunogens. METHODOLOGY AND RESULTS: We used radiation exposure to attenuate the highly virulent asexual blood stages of the murine malaria parasite P. berghei to a non-replicable, avirulent form. We tested the ability of the attenuated blood stage parasites to induce immunity to parasitemia and the symptoms of severe malaria disease. Depending on the mouse genetic background, a single high dose immunization without adjuvant protected mice from parasitemia and severe disease (CD1 mice or from experimental cerebral malaria (ECM (C57BL/6 mice. A low dose immunization did not protect against parasitemia or severe disease in either model after one or two immunizations. The protection from ECM was associated with a parasite specific antibody response and also with a lower level of splenic parasite-specific IFN-γ production, which is a mediator of ECM pathology in C57BL/6 mice. Surprisingly, there was no difference in the sequestration of CD8+ T cells and CD45+ CD11b+ macrophages in the brains of immunized, ECM-protected mice. CONCLUSIONS: This report further demonstrates the effectiveness of a whole parasite blood-stage vaccine in inducing immunity to malaria and explicitly demonstrates its effectiveness against ECM, the most pathogenic consequence of malaria infection. This experimental model will be important to explore the formulation of whole parasite blood-stage vaccines against malaria and to investigate the immune mechanisms that mediate protection against parasitemia and cerebral malaria.

  1. Asexual Reproduction in Holothurians

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    Igor Yu. Dolmatov

    2014-01-01

    Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holot...

  2. Asexual reproduction in holothurians.

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    Dolmatov, Igor Yu

    2014-01-01

    Aspects of asexual reproduction in holothurians are discussed. Holothurians are significant as fishery and aquaculture items and have high commercial value. The last review on holothurian asexual reproduction was published 18 years ago and included only 8 species. An analysis of the available literature shows that asexual reproduction has now been confirmed in 16 holothurian species. Five additional species are also most likely capable of fission. The recent discovery of new fissiparous holothurian species indicates that this reproduction mode is more widespread in Holothuroidea than previously believed. New data about the history of the discovery of asexual reproduction in holothurians, features of fission, and regeneration of anterior and posterior fragments are described here. Asexual reproduction is obviously controlled by the integrated systems of the organism, primarily the nervous system. Special molecular mechanisms appear to determine the location where fission occurs along the anterior-posterior axis of the body. Alteration of the connective tissue strength of the body wall may play an important role during fission of holothurians. The basic mechanism of fission is the interaction of matrix metalloproteinases, their inhibitors, and enzymes forming cross-link complexes between fibrils of collagen. The population dynamics of fissiparous holothurians are discussed.

  3. A validated measure of no sexual attraction: the Asexuality Identification Scale.

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    Yule, Morag A; Brotto, Lori A; Gorzalka, Boris B

    2015-03-01

    Human asexuality has been described as a lack of sexual attraction toward anyone or anything. One percent of the adult population is thought to be asexual, and research suggests that asexuality is best conceptualized as a sexual orientation. A serious limitation in past research on asexuality has been the complete lack of a validated tool to measure asexuality. Due to limitations in recruiting sufficiently powered local samples, most studies have relied on recruiting via online web-based asexual communities. This is problematic because it limits the sample to individuals who have been recruited through established asexuality networks/communities. The present study aimed to develop and validate a self-report questionnaire to assess asexuality. The questionnaire was intended to provide a valid measure independent of whether the individual self-identified as asexual and was developed in several stages, including: development and administration of open-ended questions (209 participants: 139 asexual and 70 sexual); administration and analysis of resulting 111 items (917 participants: 165 asexual and 752 sexual); administration and analysis of 37 retained items (1,242 participants: 316 asexual and 926 sexual); and validity analysis of the final items. The resulting Asexuality Identification Scale (AIS), a 12-item questionnaire, is a brief, valid, and reliable self-report instrument for assessing asexuality. It is psychometrically sound, easy to administer, and has demonstrated ability to discriminate between sexual and asexual individuals. It should prove useful to allow researchers to recruit more representative samples of the asexual population, permitting for an increased understanding of asexuality.

  4. Pf155/RESA protein influences the dynamic microcirculatory behavior of ring-stage Plasmodium falciparum infected red blood cells

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    Diez-Silva, Monica; Park, Yongkeun; Huang, Sha; Bow, Hansen; Mercereau-Puijalon, Odile; Deplaine, Guillaume; Lavazec, Catherine; Perrot, Sylvie; Bonnefoy, Serge; Feld, Michael S.; Han, Jongyoon; Dao, Ming; Suresh, Subra

    2012-08-01

    Proteins exported by Plasmodium falciparum to the red blood cell (RBC) membrane modify the structural properties of the parasitized RBC (Pf-RBC). Although quasi-static single cell assays show reduced ring-stage Pf-RBCs deformability, the parameters influencing their microcirculatory behavior remain unexplored. Here, we study the dynamic properties of ring-stage Pf-RBCs and the role of the parasite protein Pf155/Ring-Infected Erythrocyte Surface Antigen (RESA). Diffraction phase microscopy revealed RESA-driven decreased Pf-RBCs membrane fluctuations. Microfluidic experiments showed a RESA-dependent reduction in the Pf-RBCs transit velocity, which was potentiated at febrile temperature. In a microspheres filtration system, incubation at febrile temperature impaired traversal of RESA-expressing Pf-RBCs. These results show that RESA influences ring-stage Pf-RBCs microcirculation, an effect that is fever-enhanced. This is the first identification of a parasite factor influencing the dynamic circulation of young asexual Pf-RBCs in physiologically relevant conditions, offering novel possibilities for interventions to reduce parasite survival and pathogenesis in its human host.

  5. Morphological characterization of the asexual reproduction in the acorn worm Balanoglossus simodensis.

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    Miyamoto, Norio; Saito, Yasunori

    2010-09-01

    The acorn worm Balanoglossus simodensis reproduces asexually by fragmentation and subsequent regeneration from the body fragments. We examined the morphogenesis of its asexual reproduction. At first, we collected asexually reproducing specimens and observed their morphogenesis. Then, we succeeded in inducing the asexual reproduction artificially by cutting the worm at the end of the genital region. The process of morphogenesis is completely the same between naturally collected and artificially induced specimens. The stages during morphogenesis were established on the basis of the external features of the asexually reproducing fragments. The internal features of the fragments were also examined at each stage. In a separate phase of the study, the capacity for regeneration of some body parts was also examined by dividing intact worms into about 10 fragments. Although the capacity for regeneration varied among the different body parts, some fragments regenerated into complete individuals in 1 month. The process of regeneration was the same as that in the asexually produced fragments.

  6. The Plasmodium falciparum, Nima-related kinase Pfnek-4: a marker for asexual parasites committed to sexual differentiation

    Directory of Open Access Journals (Sweden)

    Reininger Luc

    2012-07-01

    Full Text Available Abstract Background Malaria parasites undergo, in the vertebrate host, a developmental switch from asexual replication to sexual differentiation leading to the formation of gametocytes, the only form able to survive in the mosquito vector. Regulation of the onset of the sexual phase remains largely unknown and represents an important gap in the understanding of the parasite’s complex biology. Methods The expression and function of the Nima-related kinase Pfnek-4 during the early sexual development of the human malaria parasite Plasmodium falciparum were investigated, using three types of transgenic Plasmodium falciparum 3D7 lines: (i episomally expressing a Pfnek-4-GFP fusion protein under the control of its cognate pfnek-4 promoter; (ii episomally expressing negative or positive selectable markers, yeast cytosine deaminase-uridyl phosphoribosyl transferase, or human dihydrofolate reductase, under the control of the pfnek-4 promoter; and (iii lacking a functional pfnek-4 gene. Parasite transfectants were analysed by fluorescence microscopy and flow cytometry. In vitro growth rate and gametocyte formation were determined by Giemsa-stained blood smears. Results The Pfnek-4-GFP protein was found to be expressed in stage II to V gametocytes and, unexpectedly, in a subset of asexual-stage parasites undergoing schizogony. Culture conditions stimulating gametocyte formation resulted in significant increase of this schizont subpopulation. Moreover, sorted asexual parasites expressing the Pfnek-4-GFP protein displayed elevated gametocyte formation when returned to in vitro culture in presence of fresh red blood cells, when compared to GFP- parasites from the same initial population. Negative selection of asexual parasites expressing pfnek-4 showed a marginal reduction in growth rate, whereas positive selection caused a marked reduction in parasitaemia, but was not sufficient to completely abolish proliferation. Pfnek-4- clones are not affected in their

  7. Robust inducible Cre recombinase activity in the human malaria parasite Plasmodium falciparum enables efficient gene deletion within a single asexual erythrocytic growth cycle.

    Science.gov (United States)

    Collins, Christine R; Das, Sujaan; Wong, Eleanor H; Andenmatten, Nicole; Stallmach, Robert; Hackett, Fiona; Herman, Jean-Paul; Müller, Sylke; Meissner, Markus; Blackman, Michael J

    2013-05-01

    Asexual blood stages of the malaria parasite, which cause all the pathology associated with malaria, can readily be genetically modified by homologous recombination, enabling the functional study of parasite genes that are not essential in this part of the life cycle. However, no widely applicable method for conditional mutagenesis of essential asexual blood-stage malarial genes is available, hindering their functional analysis. We report the application of the DiCre conditional recombinase system to Plasmodium falciparum, the causative agent of the most dangerous form of malaria. We show that DiCre can be used to obtain rapid, highly regulated site-specific recombination in P. falciparum, capable of excising loxP-flanked sequences from a genomic locus with close to 100% efficiency within the time-span of a single erythrocytic growth cycle. DiCre-mediated deletion of the SERA5 3' UTR failed to reduce expression of the gene due to the existence of alternative cryptic polyadenylation sites within the modified locus. However, we successfully used the system to recycle the most widely used drug resistance marker for P. falciparum, human dihydrofolate reductase, in the process producing constitutively DiCre-expressing P. falciparum clones that have broad utility for the functional analysis of essential asexual blood-stage parasite genes.

  8. Dual stage synthesis and crucial role of cytoadherence-linked asexual gene 9 in the surface expression of malaria parasite var proteins

    DEFF Research Database (Denmark)

    Goel, Suchi; Valiyaveettil, Manojkumar; Achur, Rajeshwara N;

    2010-01-01

    ring and late trophozoite stages. Localization studies revealed that a substantial level of CLAG9 is located mainly at or in close proximity of the IRBC membrane in association with VAR2CSA. Upon treatment of IRBCs with trypsin, a significant amount of CLAG9 (˜150 kDa) was converted into ˜142-k......Da polypeptide. Together these data demonstrate that a considerable amount of CLAG9 is embedded in the IRBC membrane such that at least a portion of the polypeptide at either N or C terminus is exposed on the cell surface. In parasites lacking CLAG9, VAR2CSA failed to express on the IRBC surface and was located...... within the parasite. Based on these findings, we propose that CLAG9 plays a critical role in the trafficking of PfEMP1s onto the IRBC surface. These results have important implications for the development of therapeutics for cerebral, placental, and other cytoadherence-associated malaria illnesses....

  9. Epigenetic variation in asexually reproducing organisms

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Preite, V.

    2014-01-01

    The role that epigenetic inheritance can play in adaptation may differ between sexuals and asexuals because (1) the dynamics of adaptation differ under sexual and asexual reproduction and the opportunities offered by epigenetic inheritance may affect these dynamics differently; and (2) in asexual re

  10. Sexual and asexual oogenesis require the expression of unique and shared sets of genes in the insect Acyrthosiphon pisum

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    Gallot Aurore

    2012-02-01

    Full Text Available Abstract Background Although sexual reproduction is dominant within eukaryotes, asexual reproduction is widespread and has evolved independently as a derived trait in almost all major taxa. How asexuality evolved in sexual organisms is unclear. Aphids, such as Acyrthosiphon pisum, alternate between asexual and sexual reproductive means, as the production of parthenogenetic viviparous females or sexual oviparous females and males varies in response to seasonal photoperiodism. Consequently, sexual and asexual development in aphids can be analyzed simultaneously in genetically identical individuals. Results We compared the transcriptomes of aphid embryos in the stages of development during which the trajectory of oogenesis is determined for producing sexual or asexual gametes. This study design aimed at identifying genes involved in the onset of the divergent mechanisms that result in the sexual or asexual phenotype. We detected 33 genes that were differentially transcribed in sexual and asexual embryos. Functional annotation by gene ontology (GO showed a biological signature of oogenesis, cell cycle regulation, epigenetic regulation and RNA maturation. In situ hybridizations demonstrated that 16 of the differentially-transcribed genes were specifically expressed in germ cells and/or oocytes of asexual and/or sexual ovaries, and therefore may contribute to aphid oogenesis. We categorized these 16 genes by their transcription patterns in the two types of ovaries; they were: i expressed during sexual and asexual oogenesis; ii expressed during sexual and asexual oogenesis but with different localizations; or iii expressed only during sexual or asexual oogenesis. Conclusions Our results show that asexual and sexual oogenesis in aphids share common genetic programs but diverge by adapting specificities in their respective gene expression profiles in germ cells and oocytes.

  11. Asexual reproduction: genetics and evolutionary aspects.

    Science.gov (United States)

    de Meeûs, T; Prugnolle, F; Agnew, P

    2007-06-01

    Reproduction is essential to all organisms if they are to contribute to the next generation. There are various means and ways of achieving this goal. This review focuses on the role of asexual reproduction for eukaryotic organisms and how its integration in a life cycle can influence their population genetics and evolution. An important question for evolutionary biologists as to why some organisms reproduce sexually, as opposed to asexually, is addressed. We also discuss the economic and medical importance of asexual organisms.

  12. Synthetic TLR4 agonists enhance functional antibodies and CD4+ T-cell responses against the Plasmodium falciparum GMZ2.6C multi-stage vaccine antigen

    DEFF Research Database (Denmark)

    Baldwin, Susan L; Roeffen, Will; Singh, Susheel K;

    2016-01-01

    of the sexual-stage protein Pfs48/45-6C genetically fused to GMZ2, an asexual vaccine antigen in advanced clinical development. To select the most suitable vaccine formulation for downstream clinical studies, GMZ2.6C was tested with various immune modulators in different adjuvant formulations (stable emulsions......A subunit vaccine targeting both transmission and pathogenic asexual blood stages of Plasmodium falciparum, i.e., a multi-stage vaccine, could be a powerful tool to combat malaria. Here, we report production and characterization of the recombinant protein GMZ2.6C, which contains a fragment...

  13. Asexual Plant Reproduction. Agricultural Lesson Plans.

    Science.gov (United States)

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    These lesson plans are intended for use in conducting classes on asexual plant reproduction. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about asexual plant reproduction/propagation. The following topics are among those discussed: plant reproduction methods,…

  14. Relationship between blood pressure variability and different renal function impairment stages in elderly hypertension patients

    Institute of Scientific and Technical Information of China (English)

    王云

    2014-01-01

    Objective To observe the change of blood pressure variability(BPV)in elderly hypertension patients,and to analyze the correlation between BPV and stages of renal function damage.Methods 127 elderly primary hypertensive patients with chronic kidney disease(CKD)were divided into three groups:stage 2 CKD group(aged 60-

  15. Blood splash in lambs-a preliminary study using the one-stage prothrombin time test.

    Science.gov (United States)

    Restall, D J

    1981-02-01

    Lambs from a flock in which a high incidence of blood splash had been detected were examined using the one-stage prothrombin test. For comparison lambs from a commercial slaughter line were also examined. All the affected lambs and 35·4% from the slaughter line had extended prothrombin times, and a relationship between extended prothrombin times and the occurrence of blood splash was established. Investigation of the pastures grazed by the affected flock showed the presence of coumarin producing plants and grasses. Some coumarin drugs prolong one-stage prothrombin times, and more importantly, induce capillary fragility, thus predisposing animals to blood splash.

  16. The influence of Maloprim chemoprophylaxis on cellular and humoral immune responses to Plasmodium falciparum asexual blood stage antigens in schoolchildren living in a malaria endemic area of Mozambique

    DEFF Research Database (Denmark)

    Hogh, B; Thompson, R; Lobo, V;

    1994-01-01

    antigens. The study was carried out in the Escola Primária de Lingamo, a primary school in a suburban area of Maputo, Mozambique. A cohort of 392 schoolchildren (aged 7-12 years) was randomly allocated to two equal groups, one receiving chemoprophylaxis with dapsone/pyrimethamine (Maloprim), the other...... assays in vitro. Anti-GLURP and anti-Pf155/RESA antibodies were detected by enzyme-linked immunosorbent assay (ELISA) and erythrocyte membrane immunofluorescence (EMIF), and total anti-P. falciparum antibodies were measured by indirect fluorescent antibody test (IFAT). Immunological reactivities were...

  17. The Plasmodium falciparum blood stages acquire factor H family proteins to evade destruction by human complement.

    Science.gov (United States)

    Rosa, Thiago F A; Flammersfeld, Ansgar; Ngwa, Che J; Kiesow, Meike; Fischer, Rainer; Zipfel, Peter F; Skerka, Christine; Pradel, Gabriele

    2016-04-01

    The acquisition of regulatory proteins is a means of blood-borne pathogens to avoid destruction by the human complement. We recently showed that the gametes of the human malaria parasite Plasmodium falciparum bind factor H (FH) from the blood meal of the mosquito vector to assure successful sexual reproduction, which takes places in the mosquito midgut. While these findings provided a first glimpse of a complex mechanism used by Plasmodium to control the host immune attack, it is hitherto not known, how the pathogenic blood stages of the malaria parasite evade destruction by the human complement. We now show that the human complement system represents a severe threat for the replicating blood stages, particularly for the reinvading merozoites, with complement factor C3b accumulating on the surfaces of the intraerythrocytic schizonts as well as of free merozoites. C3b accumulation initiates terminal complement complex formation, in consequence resulting in blood stage lysis. To inactivate C3b, the parasites bind FH as well as related proteins FHL-1 and CFHR-1 to their surface, and FH binding is trypsin-resistant. Schizonts acquire FH via two contact sites, which involve CCP modules 5 and 20. Blockage of FH-mediated protection via anti-FH antibodies results in significantly impaired blood stage replication, pointing to the plasmodial complement evasion machinery as a promising malaria vaccine target.

  18. Can growth inhibition assays (GIA) predict blood-stage malaria vaccine efficacy?

    Science.gov (United States)

    Duncan, Christopher J A; Hill, Adrian V S; Ellis, Ruth D

    2012-06-01

    An effective vaccine against P. falciparum malaria remains a global health priority. Blood-stage vaccines are an important component of this effort, with some indications of recent progress. However only a fraction of potential blood-stage antigens have been tested, highlighting a critical need for efficient down-selection strategies. Functional in vitro assays such as the growth/invasion inhibition assays (GIA) are widely used, but it is unclear whether GIA activity correlates with protection or predicts vaccine efficacy. While preliminary data in controlled human malaria infection (CHMI) studies indicate a possible association between in vitro and in vivo parasite growth rates, there have been conflicting results of immunoepidemiology studies, where associations with exposure rather than protection have been observed. In addition, GIA-interfering antibodies in vaccinated individuals from endemic regions may limit assay sensitivity in heavily malaria-exposed populations. More work is needed to establish the utility of GIA for blood-stage vaccine development.

  19. Mitochondrial peroxidase TPx-2 is not essential in the blood and insect stages of Plasmodium berghei

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    Masuda-Suganuma Hirono

    2012-11-01

    Full Text Available Abstract Background Malaria parasites actively proliferate in the body of their vertebrate and insect hosts, and are subjected to the toxic effects of reactive oxygen species. The antioxidant defenses of malaria parasites are considered to play essential roles in their survival and are thus considered promising targets for intervention. We sought to identify the cellular function of thioredoxin peroxidase-2 (TPx-2, which is expressed in the mitochondria, by disrupting the TPx-2 gene (pbtpx-2 of the rodent malaria parasite Plasmodium berghei. Findings In three independent experiments, two disruptant populations (TPx-2 KO and three wild-type parasite populations with pyrimethamine resistance (dhfr-ts/mt at the DHFR-TS locus and intact pbtpx-2 (TPx-2 WT were obtained and cloned. Null expression of TPx-2 in the KO population was confirmed by RT-PCR and Western blot analyses. The TPx-2 KO parasite developed normally in mouse erythrocytes and multiplied at a rate similar to that of the TPx-2 WT parasite during the experimental period. The peak period of gametocytemia was delayed by 1 day in the TPx-2 KO compared with that of the TPx-2 WT and the parent parasite, however, the highest gametocyte number was comparable. The number of midgut oocysts in the TPx-2 KO at 14 days post feeding was comparable to that of the TPx-2 WT. Conclusions The present finding suggests that mitochondrial Prx TPx-2 is not essential for asexual and the insect stage development of the malaria parasite.

  20. Asexual reproduction : genetics and evolutionary aspects

    OpenAIRE

    DE Meeûs, Thierry; Prugnolle, Franck; Agnew, Philip

    2007-01-01

    Reproduction is essential to all organisms if they are to contribute to the next generation. There are various means and ways of achieving this goal. This review focuses on the role of asexual reproduction for eukaryotic organisms and how its integration in a life cycle can influence their population genetics and evolution. An important question for evolutionary biologists as to why some organisms reproduce sexually, as opposed to asexually, is addressed. We also discuss the economic and medi...

  1. Association between absolute blood eosinophil count and CKD stages among cardiac patients.

    Science.gov (United States)

    Ishii, Rui; Fujita, Shu-Ichi; Kizawa, Shun; Sakane, Kazushi; Morita, Hideaki; Ozeki, Michishige; Sohmiya, Koichi; Hoshiga, Masaaki; Ishizaka, Nobukazu

    2016-02-01

    Elevated eosinophil count was shown to be associated with the development of cholesterol embolization syndrome, a potentially life-threatening condition, after catheter-based procedures. We investigated the association between stages of chronic kidney disease (CKD) and the absolute eosinophil count (AEC) among cardiac patients. CKD stages were determined solely on the estimated glomerular filtration rate or requirement for hemodialysis. Eosinophilia is defined as an eosinophil count exceeding 500/μL. A total of 1022 patients were enrolled in the current study, and eosinophil counts (/μL) in the first through fourth eosinophil count quartiles were blood pressure, and total white blood cell count. Similarly, after adjustment for the same variables, eosinophilia was associated with severe renal dysfunction with an odds ratio of 2.60 (95 % confidence interval, 1.08-6.26, P count was positively associated with higher CKD stages among cardiology patients, some fraction of which might be related to subclinical cholesterol embolization.

  2. Action of adrenalin on the circulation of the murine Plasmodium developing stages, in different blood compartments

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    Bertani S.

    2004-12-01

    Full Text Available Adrenalin was used to investigate in vivo the circulation of the different stages of rodent Plasmodium present in the blood. A single dose of adrenalin injected to mice infected with P. yoelii resulted immediately in i a diminution of the parasitaemia of approximately 50 % in the peripheral large vessels (estimated in tail blood films, as well as in the capillaries (estimated in smears of blood collected from a fed Anopheles, and ii an increased parasitaemia in blood collected by cardiac puncture from the right heart. The numbers of young stages of P. yoelii in the peripheral blood were initially somewhat reduced but, unexpectedly, midterm trophozoites were preferentially expelled from the peripheral blood into major organs like the heart. With P. vinckei, parasitaemia decreased only when midterm trophozoites predominated, and with P. chabaudi no effect was observed at any time. We propose that midterm trophozoites, by their increased surface area, as compared to rings, and their flexibility which contrasts with the rigid schizonts, are particularly susceptible to haemodynamic perturbations.

  3. Effects of a structured treatment algorithm on blood pressure goal rates in both stage 1 and stage 2 hypertension.

    Science.gov (United States)

    Neutel, J M; Smith, D H G; Silfani, T N; Lee, Y; Weber, M A

    2006-04-01

    This study analysed the efficacy of an angiotensin receptor blocker-based treatment algorithm for achieving goal blood pressure (BP) in patients with stage 1 (systolic BP (SBP) 140-159 mmHg or diastolic BP (DBP) 90-99 mmHg) or stage 2 (SBP > or = 160 mmHg or DBP > or = 100 mmHg) hypertension. In this 24-week, open-label, multicentre study, patients followed a six-step algorithm until goal BP (mmHg) was attained. Initially, olmesartan medoxomil 20 mg/day was administered for 4 weeks. The regimen was modified every 4 weeks until goal BP was attained: increase olmesartan medoxomil to 40 mg/day; add hydrochlorothiazide (HCTZ) 12.5 mg/day; increase HCTZ to 25 mg/day; add amlodipine besylate 5 mg/day; increase amlodipine besylate to 10 mg/day. In patients with stage 1 hypertension, 80% (63/79) and 56% (44/79) achieved BP goals of mmHg and mmHg, respectively, with olmesartan medoxomil monotherapy (94% (74/79) and 89% (70/79) with olmesartan medoxomil/HCTZ double therapy, and 96% (76/79) and 98% (77/79) with addition of amlodipine besylate (triple therapy)). Mean SBP/DBP reductions were 16.7/11.6, 24.8/15.8, and 26.4/16.5 mmHg for mono-, double-, and triple-therapy, respectively. In patients with stage 2 hypertension, 42% (42/100) and 19% (19/100) achieved BP goals of mmHg and mmHg, respectively, with monotherapy (75% (75/100) and 54% (54/100) with double therapy, and 90% (90/100) and 81% (81/100) with triple-therapy). Mean SBP/DBP reductions in stage 2 patients were 18.4/10.0, 32.7/16.3, and 39.1/19.4 mmHg for mono-, double, and triple therapy, respectively. Overall, most patients with stage 1 or stage 2 hypertension achieved goal BP.

  4. "Asexual propagation of a virulent clone complex in human and feline outbreak of sporotrichosis"

    NARCIS (Netherlands)

    Teixeira, Marcus de Melo; Rodrigues, Anderson Messias; Tsui, Clement K M; de Almeida, Luiz Gonzaga Paulo; Van Diepeningen, Anne D; Gerrits van den Ende, Bert; Fernandes, Geisa Ferreira; Kano, Rui; Hamelin, Richard C; Lopes-Bezerra, Leila Maria; Ribeiro Vasconcelos, Ana Tereza; de Hoog, Sybren; de Camargo, Zoilo Pires; Felipe, Maria Sueli Soares

    2014-01-01

    Sporotrichosis is one of the most frequent subcutaneous fungal infections to human and animals caused by members of the plant-associated, dimorphic genus Sporothrix. Three of the four medically important Sporothrix species found in Brazil have been considered asexual, as no sexual stage has ever bee

  5. Disruption of transitional stages in 24-h blood pressure in renal transplant recipients

    Directory of Open Access Journals (Sweden)

    Marcelo E Katz

    2012-03-01

    Full Text Available Patients with kidney replacement exhibit disrupted circadian rhythms. Most studies measuring blood pressure use the dipper/non-dipper classification, which does not consider analysis of transitional stages between low and high blood pressure, confidence intervals nor shifts in the time of peak, while assuming subjective onsets of night and day phases. In order to better understand the nature of daily variation of blood pressure in these patients, we analyzed 24h recordings from 41 renal transplant recipients using the non-symmetrical double-logistic fitting assessment which does not assume abruptness nor symmetry in ascending and descending stages of the blood pressure profile, and a cosine best-fitting regression method (Cosinor. Compared with matched controls, double-logistic fitting showed that the times for most of transitional stages (ascending systolic and descending systolic, diastolic and mean arterial pressure had a wider distribution along the 24 h. The proportion of individuals without daily blood pressure rhythm in the transplanted group was larger only for systolic arterial pressure, and the amplitude showed no significant difference. Furthermore, the transplant recipient group had a less pronounced slope in descending systolic and ascending mean blood pressure. Cosinor analysis confirmed the phase related changes, showing a wider distribution of times of peak (acrophases. We conclude that daily disruptions in renal transplant recipients can be explained not only by absence in diurnal variation, but also in changes in waveform-related parameters of the rhythm, and that distortions in the phase of the rhythm are the most consistent finding for the patients.

  6. Acquisition of growth-inhibitory antibodies against blood-stage Plasmodium falciparum.

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    Fiona J McCallum

    Full Text Available BACKGROUND: Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity in humans. However, the acquisition and activity of these antibodies is not well understood. METHODS: We tested dialysed serum and purified immunoglobulins from Kenyan children and adults for inhibition of P. falciparum blood-stage growth in vitro using different parasite lines. Serum antibodies were measured by ELISA to blood-stage parasite antigens, extracted from P. falciparum schizonts, and to recombinant merozoite surface protein 1 (42 kDa C-terminal fragment, MSP1-42. RESULTS: Antibodies to blood-stage antigens present in schizont protein extract and to recombinant MSP1-42 significantly increased with age and were highly correlated. In contrast, growth-inhibitory activity was not strongly associated with age and tended to decline marginally with increasing age and exposure, with young children demonstrating the highest inhibitory activity. Comparison of growth-inhibitory activity among samples collected from the same population at different time points suggested that malaria transmission intensity influenced the level of growth-inhibitory antibodies. Antibodies to recombinant MSP1-42 were not associated with growth inhibition and high immunoglobulin G levels were poorly predictive of inhibitory activity. The level of inhibitory activity against different isolates varied. CONCLUSIONS: Children can acquire growth-inhibitory antibodies at a young age, but once they are acquired they do not appear to be boosted by on-going exposure. Inhibitory antibodies may play a role in protection from early childhood malaria.

  7. Environmental factors influencing asexual reproductive processes in echinoderms

    OpenAIRE

    Mladenov, Pv

    1996-01-01

    This review provides a brief update of the occurrence and adaptive significance of asexual reproduction in echinoderms. It then focuses on the state of knowledge of biotic and abiotic factors that influence asexual processes in this group, particularly factors that may play a role in regulating the expression and relative proportion of asexual versus sexual phenotypes within populations of species, as well as factors modulating and triggering asexual processes. The information presented in th...

  8. Queen succession through asexual reproduction in termites.

    Science.gov (United States)

    Matsuura, Kenji; Vargo, Edward L; Kawatsu, Kazutaka; Labadie, Paul E; Nakano, Hiroko; Yashiro, Toshihisa; Tsuji, Kazuki

    2009-03-27

    The evolution and maintenance of sexual reproduction may involve important tradeoffs because asexual reproduction can double an individual's contribution to the gene pool but reduces diversity. Moreover, in social insects the maintenance of genetic diversity among workers may be important for colony growth and survival. We identified a previously unknown termite breeding system in which both parthenogenesis and sexual reproduction are conditionally used. Queens produce their replacements asexually but use normal sexual reproduction to produce other colony members. These findings show how eusociality can lead to extraordinary reproductive systems and provide important insights into the advantages and disadvantages of sex.

  9. Molecular Evidence for Ancient Asexuality in Timema Stick Insects

    NARCIS (Netherlands)

    Schwander, Tanja; Henry, Lee; Crespi, Bernard J.

    2011-01-01

    Asexuality is rare in animals in spite of its apparent advantage relative to sexual reproduction, indicating that it must be associated with profound costs [1-9]. One expectation is that reproductive advantages gained by new asexual lineages will be quickly eroded over time [3, 5-7]. Ancient asexual

  10. Circulating micro-RNAs as potential blood-based markers for early stage breast cancer detection.

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    Michael G Schrauder

    Full Text Available INTRODUCTION: MicroRNAs (miRNAs, miRs are a class of small, non-coding RNA molecules with relevance as regulators of gene expression thereby affecting crucial processes in cancer development. MiRNAs offer great potential as biomarkers for cancer detection due to their remarkable stability in blood and their characteristic expression in many different diseases. We investigated whether microarray-based miRNA profiling on whole blood could discriminate between early stage breast cancer patients and healthy controls. METHODS: We performed microarray-based miRNA profiling on whole blood of 48 early stage breast cancer patients at diagnosis along with 57 healthy individuals as controls. This was followed by a real-time semi-quantitative Polymerase Chain Reaction (RT-qPCR validation in a separate cohort of 24 early stage breast cancer patients from a breast cancer screening unit and 24 age matched controls using two differentially expressed miRNAs (miR-202, miR-718. RESULTS: Using the significance level of p<0.05, we found that 59 miRNAs were differentially expressed in whole blood of early stage breast cancer patients compared to healthy controls. 13 significantly up-regulated miRNAs and 46 significantly down-regulated miRNAs in our microarray panel of 1100 miRNAs and miRNA star sequences could be detected. A set of 240 miRNAs that was evaluated by radial basis function kernel support vector machines and 10-fold cross validation yielded a specificity of 78.8%, and a sensitivity of 92.5%, as well as an accuracy of 85.6%. Two miRNAs were validated by RT-qPCR in an independent cohort. The relative fold changes of the RT-qPCR validation were in line with the microarray data for both miRNAs, and statistically significant differences in miRNA-expression were found for miR-202. CONCLUSIONS: MiRNA profiling in whole blood has potential as a novel method for early stage breast cancer detection, but there are still challenges that need to be addressed to

  11. Chlorthalidone Plus Amiloride Reduces the Central Systolic Blood Pressure in Stage 1 Hypertension Patients

    Science.gov (United States)

    Fernandes, Leticia Aparecida Barufi; Cestario, Elizabeth do Espirito Santo; Cosenso-Martin, Luciana Neves; Vilela-Martin, Jose Fernando; Yugar-Toledo, Juan Carlos; Fuchs, Flavio Danni

    2016-01-01

    Background Hypertension reduction strategies use blood pressure in the brachial artery as the primary endpoint. Individuals who achieve the target blood pressure reduction with antihypertensive treatment have residual cardiovascular risk attributed to the difference in pressure between the aorta and brachial artery. Antihypertensive treatment affects the intrinsic properties of the vascular wall and arterial stiffness markers and consequently the central pressure. Recent publications stress the importance of adequate control of the central compared to peripheral blood pressure. Related clinical implications suggest that individuals with normal peripheral but high central blood pressure should not receive antihypertensive drugs that act on the central pressure. Therefore, they are at greater cardiovascular risk. The aim of the study was to evaluate the effect of treatment with a thiazide diuretic versus losartan on the central blood pressure in stage 1 hypertensive patients. Methods Twenty-five patients were randomized to the chlorthalidone 25 mg/amiloride 5 mg group (q.d.) and 25 patients received losartan 50 mg (b.i.d). The central systolic blood pressure (CSBP) and augmentation index (AIx 75) were assessed using applanation tonometry. The paired t-test was used to compare the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), CSBP and AIx 75 between the thiazide and losartan groups at baseline and after 6 months of treatment. Results Significant reductions in CSBP (123.3 ± 14.2 vs. 113.4 ± 111.4, P = 0.0103) and AIx 75 (87.7 ± 9.6 vs. 83.8 ± 8.9, P = 0.0289) were observed after 6 months of drug treatment with chlorthalidone 25 mg/amiloride 5 mg (q.d.). The administration of losartan 50 mg (b.i.d) did not reduce the CSBP and there were insignificant changes in the AIx 75. Conclusions Six-month treatment of chlorthalidone/amiloride but not losartan reduces the CSBP and AIx 75 in adults with stage 1

  12. Ontology for the asexual development and anatomy of the colonial chordate Botryllus schlosseri.

    Directory of Open Access Journals (Sweden)

    Lucia Manni

    Full Text Available Ontologies provide an important resource to integrate information. For developmental biology and comparative anatomy studies, ontologies of a species are used to formalize and annotate data that are related to anatomical structures, their lineage and timing of development. Here, we have constructed the first ontology for anatomy and asexual development (blastogenesis of a bilaterian, the colonial tunicate Botryllus schlosseri. Tunicates, like Botryllus schlosseri, are non-vertebrates and the only chordate taxon species that reproduce both sexually and asexually. Their tadpole larval stage possesses structures characteristic of all chordates, i.e. a notochord, a dorsal neural tube, and gill slits. Larvae settle and metamorphose into individuals that are either solitary or colonial. The latter reproduce both sexually and asexually and these two reproductive modes lead to essentially the same adult body plan. The Botryllus schlosseri Ontology of Development and Anatomy (BODA will facilitate the comparison between both types of development. BODA uses the rules defined by the Open Biomedical Ontologies Foundry. It is based on studies that investigate the anatomy, blastogenesis and regeneration of this organism. BODA features allow the users to easily search and identify anatomical structures in the colony, to define the developmental stage, and to follow the morphogenetic events of a tissue and/or organ of interest throughout asexual development. We invite the scientific community to use this resource as a reference for the anatomy and developmental ontology of B. schlosseri and encourage recommendations for updates and improvements.

  13. Sexual and asexual reproduction in the colonial ascidian Botryllus schlosseri.

    Science.gov (United States)

    Gasparini, Fabio; Manni, Lucia; Cima, Francesca; Zaniolo, Giovanna; Burighel, Paolo; Caicci, Federico; Franchi, Nicola; Schiavon, Filippo; Rigon, Francesca; Campagna, Davide; Ballarin, Loriano

    2015-01-01

    The colonial tunicate Botryllus schlosseri is a widespread filter-feeding ascidian that lives in shallow waters and is easily reared in aquaria. Its peculiar blastogenetic cycle, characterized by the presence of three blastogenetic generations (filtering adults, buds, and budlets) and by recurrent generation changes, has resulted in over 60 years of studies aimed at understanding how sexual and asexual reproduction are coordinated and regulated in the colony. The possibility of using different methodological approaches, from classical genetics to cell transplantation, contributed to the development of this species as a valuable model organism for the study of a variety of biological processes. Here, we review the main studies detailing rearing, staging methods, reproduction and colony growth of this species, emphasizing the asymmetry in sexual and asexual reproduction potential, sexual reproduction in the field and the laboratory, and self- and cross-fertilization. These data, opportunely matched with recent tanscriptomic and genomic outcomes, can give a valuable help to the elucidation of some important steps in chordate evolution.

  14. Extreme genetic diversity in asexual grass thrips populations.

    Science.gov (United States)

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations.

  15. Stage-specific education/counseling intervention in women with elevated blood pressure.

    Science.gov (United States)

    Daley, Linda K; Fish, Anne F; Frid, David J; Mitchell, G Lynn

    2009-06-01

    Many women with elevated blood pressure who seek exercise opportunities require a flexible program with systematic follow-up. The study framework included motivational readiness (exercise stage of change) from the Transtheoretical Model and self-efficacy theory. This pilot study, which used a one-group repeated measures design, tested the feasibility of a stage-specific education/counseling intervention aimed at improving exercise outcomes in women with elevated blood pressure. Forty women completed a 2.5-hour session including prescription for moderate-vigorous exercise on their own, practice on equipment, maintenance of an exercise diary, and contracting; three follow-up calls (Weeks 1, 2, 3); a visit (Week 4); and a final call (Week 5). After the intervention, 85% of women moved to or remained in the action or maintenance stages of change, the highest levels of readiness; none relapsed. Exercise self-efficacy and benefits increased and barriers decreased (Pexercise performance. The intervention was feasible. Further testing is warranted using larger samples and including a control group.

  16. Decreased mitochondrial DNA content in blood samples of patients with stage I breast cancer

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    Fokas Emmanouil

    2009-12-01

    Full Text Available Abstract Background Alterations of mitochondrial DNA (mtDNA have been implicated in carcinogenesis. We developed an accurate multiplex quantitative real-time PCR for synchronized determination of mtDNA and nuclear DNA (nDNA. We sought to investigate whether mtDNA content in the peripheral blood of breast cancer patients is associated with clinical and pathological parameters. Methods Peripheral blood samples were collected from 60 patients with breast cancer and 51 age-matched healthy individuals as control. DNA was extracted from peripheral blood for the quantification of mtDNA and nDNA, using a one-step multiplex real-time PCR. A FAM labeled MGB probe and primers were used to amplify the mtDNA sequence of the ATP 8 gene, and a VIC labeled MGB probe and primers were employed to amplify the glyceraldehyde-3-phosphate-dehydrogenase gene. mtDNA content was correlated with tumor stage, menstruation status, and age of patients as well as lymph node status and the expression of estrogen receptor (ER, progesterone receptor (PR and Her-2/neu protein. Results The content of mtDNA in stage I breast cancer patients was significantly lower than in other stages (overall P = 0.023. Reduced mtDNA was found often in post menopausal cancer group (P = 0.024. No difference in mtDNA content, in regards to age (p = 0.564, lymph node involvement (p = 0.673, ER (p = 0.877, PR (p = 0.763, and Her-2/neu expression (p = 0.335, was observed. Conclusion Early detection of breast cancer has proved difficult and current detection methods are inadequate. In the present study, decreased mtDNA content in the peripheral blood of patients with breast cancer was strongly associated with stage I. The use of mtDNA may have diagnostic value and further studies are required to validate it as a potential biomarker for early detection of breast cancer.

  17. Blood platelet and monocyte activations and relation to stages of liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Anatol Panasiuk; Janusz Zak; Edwina Kasprzycka; Katarzyna Janicka; Danuta Prokopowicz

    2005-01-01

    AIM: Blood platelets (plt) and monocytes are the cells that play a crucial role in the pathogenesis of liver damage and liver cirrhosis (LC). In this paper, the analysis of mutual relationship between platelets and monocytes activation in LC was conducted.METHODS: Immunofluorescent flow cytometry was usedto measure the percentage of activated platelet populations(CD62P, CD63), the percentage of plt-monocyte aggregates (pma) (CD41/CD45), and activated monocytes (CD11b, CD14, CD16) in the blood of 20 volunteers and 40 patientswith LC. Platelet activation markers: sP-selectin, platelet factor 4 (PF4), beta-thromboglobulin (βTG) and monocyte chemotactic peptide-1 (MCP-1) were measured and compared in different stages of LC.RESULTS: Platelet activation with the increase in bothβTG serum concentration and elevation of plt population(CD62P and CD63 as well as MIF CD62P and CD63) is elevated as LC develops and thrombocytopenia rises. There is a positive correlation between medial intensityof fluorescence (MIF) CD62P and MIF CD63 in LC. We did not show any relationship between monocyte activation and pma level. SP-selectin concentration correlates positively with plt count and pma, and negatively with stage of plt activation and MIF CD62P and MIF CD63. There was no correlation between MCP-1 concentration andpit, monocyte activation as well as pma level in LC. CD16 monocytes and MIF CD16 populations are significantlyhigher in the end stage of LC. A positive correlation occurs between the value of CD11b monocyte population andMIF CD14 and MIF CD16 on monocytes in LC.CONCLUSION: Platelet and monocyte activation plays an important role in LC. Platelet activation stage does not influence monocyte activation and production of plt aggregates with monocytes in LC. With LC development, thrombocytopenia may be the result of plt consumption in platelet-monocyte aggregates.

  18. Exercise maintains blood-brain barrier integrity during early stages of brain metastasis formation.

    Science.gov (United States)

    Wolff, Gretchen; Davidson, Sarah J; Wrobel, Jagoda K; Toborek, Michal

    2015-08-07

    Tumor cell extravasation into the brain requires passage through the blood-brain barrier, which is a highly protected microvascular environment fortified with tight junction (TJ) proteins. TJ integrity can be regulated under physiological and pathophysiological conditions. There is evidence that exercise can modulate oxidation status within the brain microvasculature and protect against tumor cell extravasation and metastasis formation. In order to study these events, mature male mice were given access to voluntary exercise on a running wheel (exercise) or access to a locked wheel (sedentary) for five weeks. The average running distance was 9.0 ± 0.2 km/day. Highly metastatic tumor cells (murine Lewis lung carcinoma) were then infused into the brain microvasculature through the internal carotid artery. Analyses were performed at early stage (48 h) and late stage (3 weeks) post tumor cell infusion. Immunohistochemical analysis revealed fewer isolated tumor cells extravasating into the brain at both 48 h and 3 weeks post surgery in exercised mice. Occludin protein levels were reduced in the sedentary tumor group, but maintained in the exercised tumor group at 48 h post tumor cell infusion. These results indicate that voluntary exercise may participate in modulating blood-brain barrier integrity thereby protecting the brain during metastatic progression.

  19. Spatial and temporal escape from fungal parasitism in natural communities of anciently asexual bdelloid rotifers.

    Science.gov (United States)

    Wilson, Christopher G; Sherman, Paul W

    2013-08-22

    Sexual reproduction is costly, but it is nearly ubiquitous among plants and animals, whereas obligately asexual taxa are rare and almost always short-lived. The Red Queen hypothesis proposes that sex overcomes its costs by enabling organisms to keep pace with coevolving parasites and pathogens. If so, the few cases of stable long-term asexuality ought to be found in groups whose coevolutionary interactions with parasites are unusually weak. In theory, antagonistic coevolution will be attenuated if hosts disperse among patches within a metapopulation separately from parasites and more rapidly. We examined whether these conditions are met in natural communities of bdelloid rotifers, one of the longest-lived asexual lineages. At any life stage, these microscopic invertebrates can tolerate the complete desiccation of their ephemeral freshwater habitats, surviving as dormant propagules that are readily carried by the wind. In our field experiments, desiccation and wind transport enabled bdelloids to disperse independently of multiple fungal parasites, in both time and space. Surveys of bdelloid communities in unmanipulated moss patches confirmed that fungal parasitism was negatively correlated with extended drought and increasing height (exposure to wind). Bdelloid ecology therefore matches a key condition of models in which asexuals persist through spatio-temporal decoupling from coevolving enemies.

  20. Red blood cell abnormalities and the pathogenesis of anemia in end-stage renal disease.

    Science.gov (United States)

    Georgatzakou, Hara T; Antonelou, Marianna H; Papassideri, Issidora S; Kriebardis, Anastasios G

    2016-08-01

    Anemia is the most common hematologic complication in end-stage renal disease (ESRD). It is ascribed to decreased erythropoietin production, shortened red blood cell (RBC) lifespan, and inflammation. Uremic toxins severely affect RBC lifespan; however, the implicated molecular pathways are poorly understood. Moreover, current management of anemia in ESRD is controversial due to the "anemia paradox" phenomenon, which underlines the need for a more individualized approach to therapy. RBCs imprint the adverse effects of uremic, inflammatory, and oxidative stresses in a context of structural and functional deterioration that is associated with RBC removal signaling and morbidity risk. RBCs circulate in hostile plasma by raising elegant homeostatic defenses. Variability in primary defect, co-morbidity, and therapeutic approaches add complexity to the pathophysiological background of the anemic ESRD patient. Several blood components have been suggested as biomarkers of anemia-related morbidity and mortality risk in ESRD. However, a holistic view of blood cell and plasma modifications through integrated omics approaches and high-throughput studies might assist the development of new diagnostic tests and therapies that will target the underlying pathophysiologic processes of ESRD anemia.

  1. Dynamics of asexual reproduction in flatworms

    Science.gov (United States)

    Schoetz, Eva-Maria; Talbot, Jared; Dunkel, Joern

    2010-03-01

    Planarians (flatworms) are one of the simplest bilaterally symmetric organisms and famous for their extraordinary regenerative capabilities. One can cut a worm in 100 pieces and after a few weeks one obtains 100 new worms that have reconstructed their entire body, including a central nervous system. This amazing regenerative capability is due to a population of stem cells distributed throughout the planarian body. These stem cells do not only allow the worms to heal without scarring after wounding, they also allow for asexual reproduction: Planarians can split themselves in two, and then regenerate the missing body parts within about a week. Naively, one would think that this kind of asexual reproduction could be captured by simple models that describe cell growth in bacteria or other lower organisms. However, we find that there is much more to the story by monitoring >15 generations of many individuals, as well as the long-term behavior (> 9 months) of worm populations under different environmental conditions, such as population density, temperature, and feeding frequency. Surprisingly, we observe that reproduction decreases with increasing food supply, opposite to the relationship between food and reproduction in other asexually reproducing organisms (e.g. bacteria, yeast), and causing obese worms. Finally, our data allows us to address the question of aging in an organism that is thought to be ``forever young''.

  2. On the Genealogy of Asexual Diploids

    Science.gov (United States)

    Lam, Fumei; Langley, Charles H.; Song, Yun S.

    Given molecular genetic data from diploid individuals that, at present, reproduce mostly or exclusively asexually without recombination, an important problem in evolutionary biology is detecting evidence of past sexual reproduction (i.e., meiosis and mating) and recombination (both meiotic and mitotic). However, currently there is a lack of computational tools for carrying out such a study. In this paper, we formulate a new problem of reconstructing diploid genealogies under the assumption of no sexual reproduction or recombination, with the ultimate goal being to devise genealogy-based tools for testing deviation from these assumptions. We first consider the infinite-sites model of mutation and develop linear-time algorithms to test the existence of an asexual diploid genealogy compatible with the infinite-sites model of mutation, and to construct one if it exists. Then, we relax the infinite-sites assumption and develop an integer linear programming formulation to reconstruct asexual diploid genealogies with the minimum number of homoplasy (back or recurrent mutation) events. We apply our algorithms on simulated data sets with sizes of biological interest.

  3. A whole parasite vaccine to control the blood stages of Plasmodium: the case for lateral thinking.

    Science.gov (United States)

    Good, Michael F

    2011-08-01

    Now, 27 years following the cloning of malaria antigens with the promise of the rapid development of a malaria vaccine, we face significant obstacles that are belatedly being addressed. Poor immunogenicity of subunit vaccine antigens and significant antigenic diversity of target epitopes represent major hurdles for which there are no clear strategies for a way forward within the current paradigm. Thus, a different paradigm - a vaccine that uses the whole organism - is now being examined. Although most advances in this approach relate to a vaccine for the pre-erythrocytic stages (sporozoites, liver stages), this opinion paper will outline the possibilities of developing a whole parasite vaccine for the blood stage and address some of the challenges for this strategy, which are entirely different to the challenges for a subunit vaccine. It is the view of the author that both vaccine paradigms should be pursued, but that success will come more quickly using the paranormal approach of exposing individuals to ultra-low doses of whole attenuated or killed parasites.

  4. Anaemia in a phase 2 study of a blood stage falciparum malaria vaccine

    Directory of Open Access Journals (Sweden)

    Guindo Aldiouma

    2011-01-01

    Full Text Available Abstract Background A Phase 1-2b study of the blood stage malaria vaccine AMA1-C1/Alhydrogel was conducted in 336 children in Donéguébougou and Bancoumana, Mali. In the Phase 2 portion of the study (n = 300, no impact on parasite density or clinical malaria was seen; however, children who received the study vaccine had a higher frequency of anaemia (defined as haemoglobin Methods To further investigate the possible impact of vaccination on anaemia, additional analyses were conducted including patients from the Phase 1 portion of the study and controlling for baseline haemoglobin, haemoglobin types S or C, alpha-thalassaemia, G6PD deficiency, and age. A multiplicative intensity model was used, which generalizes Cox regression to allow for multiple events. Frailty effects for each subject were used to account for correlation of multiple anaemia events within the same subject. Intensity rates were calculated with reference to calendar time instead of time after randomization in order to account for staggered enrollment and seasonal effects of malaria incidence. Associations of anaemia with anti-AMA1 antibody were further explored using a similar analysis. Results A strong effect of vaccine on the incidence of anaemia (risk ratio [AMA1-C1 to comparator (Hiberix]= 2.01, 95% confidence interval [1.26,3.20] was demonstrated even after adjusting for baseline haemoglobin, haemoglobinopathies, and age, and using more sophisticated statistical models. Anti-AMA1 antibody levels were not associated with this effect. Conclusions While these additional analyses show a robust effect of vaccination on anaemia, this is an intensive exploration of secondary results and should, therefore, be interpreted with caution. Possible mechanisms of the apparent adverse effect on haemoglobin of vaccination with AMA1-C1/Alhydrogel and implications for blood stage vaccine development are discussed. The potential impact on malaria-associated anaemia should be closely

  5. P. falciparum and P. vivax Epitope-Focused VLPs Elicit Sterile Immunity to Blood Stage Infections.

    Directory of Open Access Journals (Sweden)

    David C Whitacre

    Full Text Available In order to design P. falciparum preerythrocytic vaccine candidates, a library of circumsporozoite (CS T and B cell epitopes displayed on the woodchuck hepatitis virus core antigen (WHcAg VLP platform was produced. To test the protective efficacy of the WHcAg-CS VLPs, hybrid CS P. berghei/P. falciparum (Pb/Pf sporozoites were used to challenge immunized mice. VLPs carrying 1 or 2 different CS repeat B cell epitopes and 3 VLPs carrying different CS non-repeat B cell epitopes elicited high levels of anti-insert antibodies (Abs. Whereas, VLPs carrying CS repeat B cell epitopes conferred 98% protection of the liver against a 10,000 Pb/Pf sporozoite challenge, VLPs carrying the CS non-repeat B cell eptiopes were minimally-to-non-protective. One-to-three CS-specific CD4/CD8 T cell sites were also fused to VLPs, which primed CS-specific as well as WHcAg-specific T cells. However, a VLP carrying only the 3 T cell domains failed to protect against a sporozoite challenge, indicating a requirement for anti-CS repeat Abs. A VLP carrying 2 CS repeat B cell epitopes and 3 CS T cell sites in alum adjuvant elicited high titer anti-CS Abs (endpoint dilution titer >1x10(6 and provided 80-100% protection against blood stage malaria. Using a similar strategy, VLPs were constructed carrying P. vivax CS repeat B cell epitopes (WHc-Pv-78, which elicited high levels of anti-CS Abs and conferred 99% protection of the liver against a 10,000 Pb/Pv sporozoite challenge and elicited sterile immunity to blood stage infection. These results indicate that immunization with epitope-focused VLPs carrying selected B and T cell epitopes from the P. falciparum and P. vivax CS proteins can elicit sterile immunity against blood stage malaria. Hybrid WHcAg-CS VLPs could provide the basis for a bivalent P. falciparum/P. vivax malaria vaccine.

  6. Origins of asexuality in Bryobia mites (Acari: Tetranychidae

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    Menken Steph BJ

    2008-05-01

    Full Text Available Abstract Background Obligate asexual reproduction is rare in the animal kingdom. Generally, asexuals are considered evolutionary dead ends that are unable to radiate. The phytophagous mite genus Bryobia contains a large number of asexual species. In this study, we investigate the origin and evolution of asexuality using samples from 111 populations in Europe, South Africa and the United States, belonging to eleven Bryobia species. We also examine intraspecific clonal diversity for one species, B. kissophila, by genotyping individuals from 61 different populations. Knowledge on the origin of asexuality and on clonal diversity can contribute to our understanding of the paradox of sex. Results The majority (94% of 111 sampled populations reproduces asexually. Analysis of part of nuclear 28S rDNA shows that these asexuals do not form a monophyletic clade. Analysis of the mitochondrial COI region shows that intraspecific variation is extensive (up to 8.8%. Within B. kissophila, distinct clades are found, which are absent at the nuclear 28S rDNA level. Moreover, paraphyletic patterns are found at the mitochondrial DNA. Conclusion Asexuality is widespread in the genus Bryobia, signifying that some animal taxa do contain a high number of asexuals. We argue that asexuality originated multiple times within Bryobia. Wolbachia bacteria cause asexuality in at least two Bryobia species and may have infected different species independently. The high intraspecific clonal diversity and the patterns of paraphyly at the mitochondrial DNA in B. kissophila might be explained by a high mutation fixation rate and past hybridization events. Reproductive parasites like Wolbachia and Cardinium might influence these processes. We discuss the role these bacteria could play in the evolutionary success of asexual species.

  7. Peripheral blood stem cell harvest in patients with limited stage small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Katakami, Nobuyuki; Takakura, Shunji; Fujii, Hiroshi; Nishimura, Takashi; Umeda, Bunichi [Kobe City General Hospital (Japan)

    2000-06-01

    Chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood stem cells (PBSC) was performed in patients with limited stage small-cell lung cancer. Chemotherapy consisted of cisplatin/etoposide or cisplatin/adriamycin/etoposide. The amounts of CD34 positive cells and granulocyte-macrophage colony forming units (CFU-GM) collected during 2-3 courses of apheresis were 3.1{+-}2.9 x 10{sup 6}/kg (n=10) and 3.1{+-}1.5 x 10{sup 5}/kg (n=8) , respectively. Adequate amounts of PBSC were also harvested even in patients treated with concurrent chemoradiotherapy. Eight patients were successfully treated with high-dose chemotherapy consisting of ifosfamide, carboplatin and etoposide with PBSC transfusion. The patients'-bone marrow reconstruction was rapid and no treatment-related death was observed. (author)

  8. Blood lactate minimum of rats during swimming test using three incremental stages

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    Mariana de Souza Sena

    2015-09-01

    Full Text Available AbstractThe purpose of this study was to determine the lactate minimum intensity (LMI by swimming LACmintest using three incremental stages (LACmintest3 and to evaluate its sensitivity to changes in aerobic fitness (AF. Twenty Wistar rats performed: LACmintest3 (1: induction of hyperlactacidemia and incremental phase (4%, 5% and 6.5% of bw; Constant loads tests on (2 and above (3 the LMI. Half of the animals were subjected to training with the individual LMI and the tests were performed again. The mean exercise load in LACmintest3 was 5.04 ± 0.13% bw at 5.08 ± 0.55 mmol L-1 blood lactate minimum (BLM. There was a stabilize and disproportionate increase of blood lactate in tests 2 and 3, respectively. After the training period, the mean BLM was lower in the trained animals. The LACmintest3 seems to be a good indicator of LMI and responsive to changes in AF in rats subjected to swim training.

  9. SOME BIOCHEMICAL BLOOD CONSTANTS EVOLUTION IN REPORT TO THE TRAINING SCHEDULE STAGE IN SPORT HORSES

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    FLAVIA BOCHIS

    2013-12-01

    Full Text Available To determine whether a clinical examination was adequate to assess the fitness of horses in a fence course riding, and to characterize the relationship between a clinical assessment of the horse's fitness, training schedule stage and its blood biochemistry, 22 horses were monitored before (S1, during training, immediately after warming-up (S2 and after an E level fence obstacle course ride (S3. The blood samples were taken from the jugular vein in the above three mentioned phases, for the determination of total protein (g/dl, nitrogen (mg/dl, glucose (mg/dl, lactic acid (nmol/l, calcium (mg/dl, cholesterol (mg/dl and phosphorus (mg/dl. The intend of the paper is to present the obtained results as a reference study for the appropriate use by clinicians, sport horses owners and trainers in view to have a solid base in evaluation, for the adequate protection of health and welfare of the jumper horses competitors.

  10. Blood Biomarkers Associated with Cognitive Decline in Early Stage and Drug-Naive Parkinson's Disease Patients.

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    Jose A Santiago

    Full Text Available Early diagnosis of Parkinson's disease (PD continues to be a major challenge in the field. The lack of a robust biomarker to detect early stage PD patients has considerably slowed the progress toward the development of potential therapeutic agents. We have previously evaluated several RNA biomarkers in whole blood from participants enrolled in two independent clinical studies. In these studies, PD patients were medicated, thus, expression of these biomarkers in de novo patients remains unknown. To this end, we tested ten RNA biomarkers in blood samples from 99 untreated PD patients and 101 HC nested in the cross-sectional Parkinson's Progression Markers Initiative by quantitative real-time PCR. One biomarker out of ten, COPZ1 trended toward significance (nominal p = 0.009 when adjusting for age, sex, and educational level. Further, COPZ1, EFTUD2 and PTBP1 mRNAs correlated with clinical features in PD patients including the Hoehn and Yahr scale, Movement Disorder Society revision of Unified Parkinson's Disease Rating Scale (MDS-UPDRS and Montreal Cognitive Assessment (MoCA score. Levels of EFTUD2 and PTBP1 were significantly higher in cognitively normal PD patients (PD-CN compared to cognitively impaired PD patients (PD-MCI. Interestingly, blood glucose levels were significantly higher in PD and PD-MCI patients (≥ 100 mg/dL, pre-diabetes compared to HC. Collectively, we report the association of three RNA biomarkers, COPZ1, EFTUD2 and PTBP1 with clinical features including cognitive decline in early drug-naïve PD patients. Further, our results show that drug-naïve PD and PD-MCI patients have glucose levels characteristic of pre-diabetes patients, suggesting that impaired glucose metabolism is an early event in PD. Evaluation of these potential biomarkers in a larger longitudinal study is warranted.

  11. Blood Biomarkers Associated with Cognitive Decline in Early Stage and Drug-Naive Parkinson's Disease Patients.

    Science.gov (United States)

    Santiago, Jose A; Potashkin, Judith A

    2015-01-01

    Early diagnosis of Parkinson's disease (PD) continues to be a major challenge in the field. The lack of a robust biomarker to detect early stage PD patients has considerably slowed the progress toward the development of potential therapeutic agents. We have previously evaluated several RNA biomarkers in whole blood from participants enrolled in two independent clinical studies. In these studies, PD patients were medicated, thus, expression of these biomarkers in de novo patients remains unknown. To this end, we tested ten RNA biomarkers in blood samples from 99 untreated PD patients and 101 HC nested in the cross-sectional Parkinson's Progression Markers Initiative by quantitative real-time PCR. One biomarker out of ten, COPZ1 trended toward significance (nominal p = 0.009) when adjusting for age, sex, and educational level. Further, COPZ1, EFTUD2 and PTBP1 mRNAs correlated with clinical features in PD patients including the Hoehn and Yahr scale, Movement Disorder Society revision of Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and Montreal Cognitive Assessment (MoCA) score. Levels of EFTUD2 and PTBP1 were significantly higher in cognitively normal PD patients (PD-CN) compared to cognitively impaired PD patients (PD-MCI). Interestingly, blood glucose levels were significantly higher in PD and PD-MCI patients (≥ 100 mg/dL, pre-diabetes) compared to HC. Collectively, we report the association of three RNA biomarkers, COPZ1, EFTUD2 and PTBP1 with clinical features including cognitive decline in early drug-naïve PD patients. Further, our results show that drug-naïve PD and PD-MCI patients have glucose levels characteristic of pre-diabetes patients, suggesting that impaired glucose metabolism is an early event in PD. Evaluation of these potential biomarkers in a larger longitudinal study is warranted.

  12. [Asexual reproduction of planarians: metric studies].

    Science.gov (United States)

    Sheĭman, I M; Sedel'nikov, Z V; Shkutin, M F; Kreshchenko, N D

    2006-01-01

    A relationship was studied between fission and restoration of body and its individual parts under different experimental conditions in planarians of the Dugesia tigrina asexual race. The body and its fragments were studied morphomterically. After fission, the growth of planarians demonstrated topographic differences. The separated tail fragments and postpharyngeal area, in which the zone of fission is formed, were growing at the highest rate. More active growth was also noted over the long body axis. Fission and growth were more active in isolated planarians, as compared to those kept in groups.

  13. Deleterious mutation accumulation in asexual Timema stick insects.

    Science.gov (United States)

    Henry, Lee; Schwander, Tanja; Crespi, Bernard J

    2012-01-01

    Sexual reproduction is extremely widespread in spite of its presumed costs relative to asexual reproduction, indicating that it must provide significant advantages. One postulated benefit of sex and recombination is that they facilitate the purging of mildly deleterious mutations, which would accumulate in asexual lineages and contribute to their short evolutionary life span. To test this prediction, we estimated the accumulation rate of coding (nonsynonymous) mutations, which are expected to be deleterious, in parts of one mitochondrial (COI) and two nuclear (Actin and Hsp70) genes in six independently derived asexual lineages and related sexual species of Timema stick insects. We found signatures of increased coding mutation accumulation in all six asexual Timema and for each of the three analyzed genes, with 3.6- to 13.4-fold higher rates in the asexuals as compared with the sexuals. In addition, because coding mutations in the asexuals often resulted in considerable hydrophobicity changes at the concerned amino acid positions, coding mutations in the asexuals are likely associated with more strongly deleterious effects than in the sexuals. Our results demonstrate that deleterious mutation accumulation can differentially affect sexual and asexual lineages and support the idea that deleterious mutation accumulation plays an important role in limiting the long-term persistence of all-female lineages.

  14. Molecular evidence for ancient asexuality in timema stick insects.

    Science.gov (United States)

    Schwander, Tanja; Henry, Lee; Crespi, Bernard J

    2011-07-12

    Asexuality is rare in animals in spite of its apparent advantage relative to sexual reproduction, indicating that it must be associated with profound costs [1-9]. One expectation is that reproductive advantages gained by new asexual lineages will be quickly eroded over time [3, 5-7]. Ancient asexual taxa that have evolved and adapted without sex would be "scandalous" exceptions to this rule, but it is often difficult to exclude the possibility that putative asexuals deploy some form of "cryptic" sex, or have abandoned sex more recently than estimated from divergence times to sexual relatives [10]. Here we provide evidence, from high intraspecific divergence of mitochondrial sequence and nuclear allele divergence patterns, that several independently derived Timema stick-insect lineages have persisted without recombination for more than a million generations. Nuclear alleles in the asexual lineages displayed significantly higher intraindividual divergences than in related sexual species. In addition, within two asexuals, nuclear allele phylogenies suggested the presence of two clades, with sequences from the same individual appearing in both clades. These data strongly support ancient asexuality in Timema and validate the genus as an exceptional opportunity to attack the question of how asexual reproduction can be maintained over long periods of evolutionary time.

  15. Mutation-selection balance and mixed mating with asexual reproduction.

    Science.gov (United States)

    Marriage, Tara N; Orive, Maria E

    2012-09-07

    The effects of asexual reproduction on both the number of deleterious mutations per gamete and the mean fitness under mutation-selection balance are investigated. We use two simulation models, considering both finite and infinite populations. The two models incorporate asexual reproduction with varying levels of outcrossing and selfing, degrees of dominance and selection coefficients. The values for mean fitness and number of deleterious mutations per gamete are compared within and among finite and infinite populations to identify the effect of asexual reproduction on levels of load, and how asexual reproduction may interact with genetic drift (population size). Increasing asexual reproduction resulted in an increase in mean fitness and a decrease in the average number of deleterious mutations per gamete for both nearly recessive and additive alleles in both the infinite and finite simulations. Increased mean fitness with increasing asexuality is possibly due to two interacting forces: a greater opportunity for selection to act on heterozygous versus homozygous mutations and the shielding of a proportion of the population from meiotic mutations due to asexual reproduction. The results found here highlight the need to consider asexual reproduction along with mixed mating in models of genetic load and mutation-selection balance.

  16. On the asexual reproduction of Plagiochila pluma Steph.

    OpenAIRE

    Piippo, Sinikka

    1992-01-01

    Four types of asexual reproduction in Plagiochila and the Plagiochilaceae are known: propagules, caducous leaves, gemmae and cladia. Plagiochila pluma Steph. has caducous leaves and teeth with regenerants. The terms for asexual reproduction modes in liverworts are briefly discussed and new definitions proposed.

  17. Habitat heterogeneity favors asexual reproduction in natural populations of grassthrips.

    Science.gov (United States)

    Lavanchy, Guillaume; Strehler, Marie; Llanos Roman, Maria Noemi; Lessard-Therrien, Malie; Humbert, Jean-Yves; Dumas, Zoé; Jalvingh, Kirsten; Ghali, Karim; Fontcuberta García-Cuenca, Amaranta; Zijlstra, Bart; Arlettaz, Raphaël; Schwander, Tanja

    2016-08-01

    Explaining the overwhelming success of sex among eukaryotes is difficult given the obvious costs of sex relative to asexuality. Different studies have shown that sex can provide benefits in spatially heterogeneous environments under specific conditions, but whether spatial heterogeneity commonly contributes to the maintenance of sex in natural populations remains unknown. We experimentally manipulated habitat heterogeneity for sexual and asexual thrips lineages in natural populations and under seminatural mesocosm conditions by varying the number of hostplants available to these herbivorous insects. Asexual lineages rapidly replaced the sexual ones, independently of the level of habitat heterogeneity in mesocosms. In natural populations, the success of sexual thrips decreased with increasing habitat heterogeneity, with sexual thrips apparently only persisting in certain types of hostplant communities. Our results illustrate how genetic diversity-based mechanisms can favor asexuality instead of sex when sexual lineages co-occur with genetically variable asexual lineages.

  18. Biomarkers for early and late stage chronic allograft nephropathy by proteogenomic profiling of peripheral blood.

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    Sunil M Kurian

    Full Text Available BACKGROUND: Despite significant improvements in life expectancy of kidney transplant patients due to advances in surgery and immunosuppression, Chronic Allograft Nephropathy (CAN remains a daunting problem. A complex network of cellular mechanisms in both graft and peripheral immune compartments complicates the non-invasive diagnosis of CAN, which still requires biopsy histology. This is compounded by non-immunological factors contributing to graft injury. There is a pressing need to identify and validate minimally invasive biomarkers for CAN to serve as early predictors of graft loss and as metrics for managing long-term immunosuppression. METHODS: We used DNA microarrays, tandem mass spectroscopy proteomics and bioinformatics to identify genomic and proteomic markers of mild and moderate/severe CAN in peripheral blood of two distinct cohorts (n = 77 total of kidney transplant patients with biopsy-documented histology. FINDINGS: Gene expression profiles reveal over 2400 genes for mild CAN, and over 700 for moderate/severe CAN. A consensus analysis reveals 393 (mild and 63 (moderate/severe final candidates as CAN markers with predictive accuracy of 80% (mild and 92% (moderate/severe. Proteomic profiles show over 500 candidates each, for both stages of CAN including 302 proteins unique to mild and 509 unique to moderate/severe CAN. CONCLUSIONS: This study identifies several unique signatures of transcript and protein biomarkers with high predictive accuracies for mild and moderate/severe CAN, the most common cause of late allograft failure. These biomarkers are the necessary first step to a proteogenomic classification of CAN based on peripheral blood profiling and will be the targets of a prospective clinical validation study.

  19. Constraints on the evolution of asexual reproduction.

    Science.gov (United States)

    Engelstädter, Jan

    2008-11-01

    Sexual reproduction is almost ubiquitous among multicellular organisms even though it entails severe fitness costs. To resolve this apparent paradox, an extensive body of research has been devoted to identifying the selective advantages of recombination that counteract these costs. Yet, how easy is it to make the transition to asexual reproduction once sexual reproduction has been established for a long time? The present review approaches this question by considering factors that impede the evolution of parthenogenesis in animals. Most importantly, eggs need a diploid chromosome set in most species in order to develop normally. Next, eggs may need to be activated by sperm, and sperm may also contribute centrioles and other paternal factors to the zygote. Depending on how diploidy is achieved mechanistically, further problems may arise in offspring that stem from 'inbreeding depression' or inappropriate sex determination systems. Finally, genomic imprinting is another well-known barrier to the evolution of asexuality in mammals. Studies on species with occasional, deficient parthenogenesis indicate that the relative importance of these constraints may vary widely. The intimate evolutionary relations between haplodiploidy and parthenogenesis as well as implications for the clade selection hypothesis of the maintenance of sexual reproduction are also discussed.

  20. Asexuality development among middle aged and older men.

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    Yan-Ping Huang

    Full Text Available OBJECTIVES: To assess erectile function in middle-aged and older men with asexuality status and further analyze their specific reasons for this condition. SUBJECTS AND METHODS: Men who had regular sexual intercourse attempts (sex frequency ≥ 1 time per month were classified into mild erectile dysfunction (ED, moderate to severe ED and non-ED according to International Index of Erectile Function-5, and men having no sexual intercourse attempts for at least 6 months were defined as having an asexuality status. The risk factors associated with ED were collected in a sample of 1,531 Chinese men aged 40 to 80 years, and the self-report reasons for asexuality were recorded in asexual cohort individually. Comparative analyses and multivariate regression models were conducted among these groups. RESULTS: The prevalence rates of ED and asexuality status were 49.9% and 37.2%. The asexuality status group had higher risk factors than the moderate to severe ED group in terms of old age (age ≥ 65, adjusted odds ratio (OR 17.69 versus (Vs. 7.19, diabetes (crude OR: 2.40 Vs. 2.36 and hypertension (crude OR: 1.78 Vs. 1.72. The specific reasons for the asexuality status were "erectile difficulty" (52.9%, "do not care about sexuality" (53.5%", "no longer necessary to have sexuality at this age" (47.7%, "severe stress" (44.4%, "severe fatigue" (26.3% and "masturbation" (26.9%. CONCLUSIONS: Men with an asexual status suffer from higher risk factors for ED than men with moderate to severe ED. The majority of this asexual status could be attributed to a full ED, although the reasons for this transient asexuality also involved sexual attitudes and interests, sexual partners and masturbation.

  1. Blood biochemical changes in lambs infected with normal and gamma irradiated third stage larvae of Dictyocaulus filaria

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    Bhat, T.K.; Dhar, D.N.; Bansal, G.C.; Sharma, R.L. (Indian Veterinary Research Inst., Srinagar (India). Regional Centre)

    1984-09-01

    Primary infections with normal third stage larvae of Dictyocaulus filaria at a dose of 150 1/kg caused significant decrease in the levels of haemoglobin, blood glucose, serum total proteins, serum albumin, albumin/globulin ratio and increase in levels of total globulins and lactate dehydrogenase (LDH) activity in lambs. Almost similar changes in the above blood constituents excepting for haemoglobin, blood glucose and LDH activity were noticed in lambs immunised with two doses of gamma irradiation larvae and subsequently challenged with normal larvae of D. filaria at a dose of 150 1/kg. In both the infected groups, serum calcium, inorganic phosphorus, malate dehydrogenase and alkaline phosphatase activities were, however, not affected.

  2. Characterization of the Duffy-Binding-Like Domain of Plasmodium falciparum Blood-Stage Antigen 332

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    Sandra Nilsson

    2011-01-01

    Full Text Available Studies on Pf332, a major Plasmodium falciparum blood-stage antigen, have largely been hampered by the cross-reactive nature of antibodies generated against the molecule due to its high content of repeats, which are present in other malaria antigens. We previously reported the identification of a conserved domain in Pf332 with a high degree of similarity to the Duffy-binding-like (DBL domains of the erythrocyte-binding-like (EBL family. We here describe that antibodies towards Pf332-DBL are induced after repeated exposure to P. falciparum and that they are acquired early in life in areas of intense malaria transmission. Furthermore, a homology model of Pf332-DBL was found to be similar to the structure of the EBL-DBLs. Despite their similarities, antibodies towards Pf332-DBL did not display any cross-reactivity with EBL-proteins as demonstrated by immunofluorescence microscopy, Western blotting, and peptide microarray. Thus the DBL domain is an attractive region to use in further studies on the giant Pf332 molecule.

  3. Type I Interferons Regulate Immune Responses in Humans with Blood-Stage Plasmodium falciparum Infection

    Science.gov (United States)

    Montes de Oca, Marcela; Kumar, Rajiv; de Labastida Rivera, Fabian; Amante, Fiona H.; Sheel, Meru; Faleiro, Rebecca J.; Bunn, Patrick T.; Best, Shannon E.; Beattie, Lynette; Ng, Susanna S.; Edwards, Chelsea L.; Boyle, Glen M.; Price, Ric N.; Anstey, Nicholas M.; Loughland, Jessica R.; Burel, Julie; Doolan, Denise L.; Haque, Ashraful; McCarthy, James S.; Engwerda, Christian R.

    2016-01-01

    Summary The development of immunoregulatory networks is important to prevent disease. However, these same networks allow pathogens to persist and reduce vaccine efficacy. Here, we identify type I interferons (IFNs) as important regulators in developing anti-parasitic immunity in healthy volunteers infected for the first time with Plasmodium falciparum. Type I IFNs suppressed innate immune cell function and parasitic-specific CD4+ T cell IFNγ production, and they promoted the development of parasitic-specific IL-10-producing Th1 (Tr1) cells. Type I IFN-dependent, parasite-specific IL-10 production was also observed in P. falciparum malaria patients in the field following chemoprophylaxis. Parasite-induced IL-10 suppressed inflammatory cytokine production, and IL-10 levels after drug treatment were positively associated with parasite burdens before anti-parasitic drug administration. These findings have important implications for understanding the development of host immune responses following blood-stage P. falciparum infection, and they identify type I IFNs and related signaling pathways as potential targets for therapies or vaccine efficacy improvement. PMID:27705789

  4. Development of blood-stages malaria vaccines%红内期疟疾疫苗的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈琳; 黄复生

    2011-01-01

    目前发展疟疾疫苗仍然是防治和消灭疟疾感染的重要手段,红内期是疟原虫致病并引起临床症状的主要时期,发展有效的红内期疫苗不仅能减轻临床症状,还可降低血中配子体数量从而起到阻断传播作用.本文就目前红内期亚单位疫苗候选抗原及全虫疫苗的研究现状作一综述.%A key tool for control and elimination of malaria is an effective vaccine.The pathology and clinical symptoms of malaria are associated with the blood stages of the parasite's life cycle.The development of blood stage vaccines can reduce or clear the clinical symptoms and reduce the transmission through the mosquito vector.The review focuses only on advantages and challenges of candidate antigens of blood-stage subunit vaccine and whole blood-stage parasites vaccine.

  5. Generation of an antibody that recognizes Plasmodium chabaudi cysteine protease (chabaupain-1) in both sexual and asexual parasite life cycle and evaluation of chabaupain-1 vaccine potential.

    Science.gov (United States)

    Armada, Ana; Gazarini, Marcos L; Gonçalves, Lídia M; Antunes, Sandra; Custódio, Ana; Rodrigues, Armanda; Almeida, António J; Silveira, Henrique; Rosário, Virgílio do; Santos-Gomes, Gabriela; Domingos, Ana

    2013-09-01

    Malaria cysteine proteases have been shown to be immunogenic and are being exploited as serodiagnostic markers, drug and vaccine targets. Several Plasmodium spp. cysteine proteases have been described and the best characterized of these are the falcipains, a family of papain-family enzymes. Falcipain-2 and falcipain-3 act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. Falcipain-1 has less similarity to the other falcipains and its physiological role in parasite asexual blood stage still remains uncertain. Immunolocalization studies using an antibody developed against the Plasmodium chabaudi recombinant chabaupain-1, the falcipain-1 ortholog, were performed confirming its cellular localization in both erythrocyte and mosquito ookinete stage. Immunostaining of chabaupain-1 preferentially in apical portion of parasite ookinete suggests that this protease may be related with parasite egression from mosquito midgut. Immune responses to chabaupain-1 were evaluated using two different adjuvants, chitosan nanoparticles and hydroxide aluminum. Mice immunized with the recombinant protein alone or in association with nanoparticles were challenged with P. chabaudi showing that immunization with the recombinant protein confers partial protection to blood stage infection in BALB/c animal model.

  6. Origination of asexual plantlets in three species of Crassulaceae.

    Science.gov (United States)

    Guo, Jiansheng; Liu, Hailiang; He, Yangyang; Cui, Xianghuan; Du, Xiling; Zhu, Jian

    2015-03-01

    During asexual plant reproduction, cells from different organs can be reprogrammed to produce new individuals, a process that requires the coordination of cell cycle reactivation with the acquisition of other cellular morphological characteristics. However, the factors that influence the variety of asexual reproduction have not yet been determined. Here, we report on plantlet formation in Kalanchoe daigremontiana, Graptopetalum paraguayense, and Crassula portulacea (Crassulaceae) and analyse the effect of initiating cells on asexual reproduction in these three species. Additionally, the roles of WUSCHEL (WUS) and CUP-SHAPED COTYLEDON 1 (CUC1) in the asexual reproduction of these species were analysed through qRT-PCR. Our results indicated that pre-existing stem cell-like cells at the sites of asexual reproduction were responsible for the formation of plantlets. These cells were arrested in different phases of the cell cycle and showed different cell morphological characteristics and cell counts. The accumulation of auxin and cytokinin at the sites of asexual plantlet formation indicated their important functions, particularly for cell cycle reactivation. These differences may influence the pattern and complexity of asexual reproduction in these Crassulaceae species. Additionally, the dynamic expression levels of CUC1 and WUS may indicate that CUC1 functions in the formation of callus and shoot meristems; whereas, WUS was only associated with shoot induction.

  7. Genetic causes of transitions from sexual reproduction to asexuality in plants and animals.

    Science.gov (United States)

    Neiman, M; Sharbel, T F; Schwander, T

    2014-07-01

    The persistence of sexual reproduction in the face of competition from asexual invaders is more likely if asexual lineages are produced infrequently or have low fitness. The generation rate and success of new asexual lineages will be influenced by the proximate mechanisms underlying transitions to asexuality. As such, characterization of these mechanisms can help explain the distribution of reproductive modes among natural populations. Here, we synthesize the literature addressing proximate causes of transitions from sexual to asexual reproduction in plants and animals. In cyclical and facultatively asexual taxa, individual mutations can cause obligate asexuality. The evolution of asexuality in obligately sexual groups is more complex, requiring the simultaneous acquisition of two traits generally controlled by different genetic factors: unreduced gamete formation and spontaneous development of unfertilized gametes. At least three 'pre-adaptations' could favour transitions to obligate asexuality in obligate sexuals. First, linkage among loci affecting separate key components of asexuality facilitates its spread, with evidence for these linkage blocks in plants. Second, asexuality should evolve more readily in haplodiploids; support for this hypothesis comes from two examples where a single locus causes transitions to asexuality. Third, standing genetic variation for the production of unreduced gametes could facilitate transitions to asexuality, but whether the ability to produce unreduced gametes contributes to the evolution of obligate asexuality remains unclear. We close by reviewing the associations between asexuality, hybridization and polyploidy, and argue that current data suggest that hybridization is more likely to play a causal role in transitions to asexuality than polyploidy.

  8. Nebivolol reduces central blood pressure in stage I hypertensive patients: experimental single cohort study

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    Renan Oliveira Vaz-de-Melo

    Full Text Available CONTEXT AND OBJECTIVES: Assessment of central blood pressure (BP has grown substantially over recent years because evidence has shown that central BP is more relevant to cardiovascular outcomes than peripheral BP. Thus, different classes of antihypertensive drugs have different effects on central BP despite similar reductions in brachial BP. The aim of this study was to investigate the effect of nebivolol, a β-blocker with vasodilator properties, on the biochemical and hemodynamic parameters of hypertensive patients.DESIGN AND SETTING: Experimental single cohort study conducted in the outpatient clinic of a university hospital.METHODS: Twenty-six patients were recruited. All of them underwent biochemical and hemodynamic evaluation (BP, heart rate (HR, central BP and augmentation index before and after 3 months of using nebivolol.RESULTS: 88.5% of the patients were male; their mean age was 49.7 ± 9.3 years and most of them were overweight (29.6 ± 3.1 kg/m2 with large abdominal waist (102.1 ± 7.2 cm. There were significant decreases in peripheral systolic BP (P = 0.0020, diastolic BP (P = 0.0049, HR (P < 0.0001 and central BP (129.9 ± 12.3 versus 122.3 ± 10.3 mmHg; P = 0.0083 after treatment, in comparison with the baseline values. There was no statistical difference in the augmentation index or in the biochemical parameters, from before to after the treatment.CONCLUSIONS: Nebivolol use seems to be associated with significant reduction of central BP in stage I hypertensive patients, in addition to reductions in brachial systolic and diastolic BP.

  9. Evidence of parasexual activity in "asexual amoebae" Cochliopodium spp. (Amoebozoa): extensive cellular and nuclear fusion.

    Science.gov (United States)

    Tekle, Yonas I; Anderson, O Roger; Lecky, Ariel F

    2014-09-01

    The majority of microbial eukaryotes have long been considered asexual, though new evidence indicates sex, or sexual-like (parasexual) behaviors that deviate from the usual union of two gametes, among other variant aspects. Over a dozen amoebozoans are implicated to have sexual stages. However, the exact mechanism by which sex occurs in these lineages remains elusive. This is mainly due to the diverse quality and cryptic nature of their life cycle. In this study we present evidence of some previously unreported aspects of the life cycle of an amoeba, Cochliopodium, that undergoes unusual intraspecific interactions using light microscopy and immunocytochemistry. Similar to other amoebozoans, Cochliopodium, is considered asexual with no published reports of sex or parasexuality. We also investigated environmental conditions that govern the observed intraspecific interactions. Both light microscopic and immunocytochemistry evidence demonstrates Cochliopodium undergoes cellular fusion (plasmogamy) and nuclear fusion (karyogamy). Large plasmodia eventually undergo karyogamy and contain large fused, polyploid, nuclei. These are observed to fragment, subsequently, by karyotomy (nuclear fission) and cytoplasmic fission to yield uninucleated amoebae. This process could lead to a non-meiotic, parasexual exchange of chromosomes in Cochliopodium. These findings strongly suggest that Cochliopodium is involved in parasexual activity and should no longer be considered strictly asexual.

  10. Blood stage malaria vaccine eliciting high antigen-specific antibody concentrations confers no protection to young children in Western Kenya.

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    Bernhards R Ogutu

    Full Text Available The antigen, falciparum malaria protein 1 (FMP1, represents the 42-kDa C-terminal fragment of merozoite surface protein-1 (MSP-1 of the 3D7 clone of P. falciparum. Formulated with AS02 (a proprietary Adjuvant System, it constitutes the FMP1/AS02 candidate malaria vaccine. We evaluated this vaccine's safety, immunogenicity, and efficacy in African children.A randomised, double-blind, Phase IIb, comparator-controlled trial.The trial was conducted in 13 field stations of one mile radii within Kombewa Division, Nyanza Province, Western Kenya, an area of holoendemic transmission of P. falciparum. We enrolled 400 children aged 12-47 months in general good health.Children were randomised in a 1ratio1 fashion to receive either FMP1/AS02 (50 microg or Rabipur(R rabies vaccine. Vaccinations were administered on a 0, 1, and 2 month schedule. The primary study endpoint was time to first clinical episode of P. falciparum malaria (temperature >/=37.5 degrees C with asexual parasitaemia of >/=50,000 parasites/microL of blood occurring between 14 days and six months after a third dose. Case detection was both active and passive. Safety and immunogenicity were evaluated for eight months after first immunisations; vaccine efficacy (VE was measured over a six-month period following third vaccinations.374 of 400 children received all three doses and completed six months of follow-up. FMP1/AS02 had a good safety profile and was well-tolerated but more reactogenic than the comparator. Geometric mean anti-MSP-1(42 antibody concentrations increased from1.3 microg/mL to 27.3 microg/mL in the FMP1/AS02 recipients, but were unchanged in controls. 97 children in the FMP1/AS02 group and 98 controls had a primary endpoint episode. Overall VE was 5.1% (95% CI: -26% to +28%; p-value = 0.7.FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-1(42 vaccine development should focus on other formulations and antigen constructs

  11. Relative importance of sexual and asexual reproduction for range expansion of Spartina alterniflora in different tidal zones on Chinese coast

    Science.gov (United States)

    Liu, Huiyu; Lin, Zhenshan; Zhang, Mingyang; Qi, Xiangzhen

    2017-02-01

    In this paper, based on spatially explicit individual-based model and global sensitivity analysis, the relative importance of sexual and asexual reproduction for range expansion of Spartina alterniflora in different tidal zones during different invasion stages has been revealed. The results showed that: 1) sexual reproduction is thought to accelerate the range expansion in middle and high tidal zones; 2) seed dispersal and adult survival rate are the two most important for range expansion of S. alterniflora during most invasion stages in all tidal zones. However, in high tidal zone, the importance of seed dispersal distance is much less than in low and middle tidal zones, and that of sexual reproduction is also great, which cannot be ignored. In middle tidal zone, the importance of adult survival rate is less important than in high and low tidal zones, and is very close to asexual reproduction. Moreover, there are significant fluctuations among the importance of different parameters except seed dispersal distance, indicating strong interactions. 3) the importance of adult survival rate and asexual reproduction is much greater than seed dispersal distance during early invasion. Especially, their importance is much higher during early and middle invasion stages in high tidal zone. During early invasion stages, the interactions among different parameters are very strong. To enhance the invasion control efficiency, it is necessary to take different control measures according to different tidal zones and invasion stages.

  12. Can perfusion CT assessment of primary colorectal adenocarcinoma blood flow at staging predict for subsequent metastatic disease? A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Vicky [Mount Vernon Hospital, Paul Strickland Scanner Centre, Northwood (United Kingdom); Halligan, Steve [University College Hospital, Department of Academic Radiology, London (United Kingdom); Wellsted, David M. [University of Hertfordshire, Health Research and Development Support Unit, Hatfield (United Kingdom); Bartram, Clive I. [St Mark' s Hospital, Intestinal Imaging Centre, Harrow (United Kingdom)

    2009-01-15

    We aimed to determine whether perfusion CT measurements at colorectal cancer staging may predict for subsequent metastatic relapse. Fifty two prospective patients underwent perfusion CT at staging to estimate tumour blood flow, blood volume, mean transit time, and permeability surface area product. Patients considered metastasis free and suitable for surgery underwent curative resection subsequently. At final analysis, a median of 48.6 months post-surgery, patients were divided into those who remained disease free, and those with subsequent metastases. Vascular parameters for these two groups were compared using t-testing, and receiver operator curve analysis was performed to determine the sensitivity and specificity of these vascular parameters for predicting metastases. Thirty seven (71%) patients underwent curative surgery; data were available for 35: 26 (74%) remained disease free; 9 (26%) recurred (8 metastatic, 1 local). Tumour blood flow differed significantly between disease-free and metastatic patients (76.0 versus 45.7 ml/min/100 g tissue; p=0.008). With blood flow <64 ml/min/100 g tissue, sensitivity and specificity (95% CI) for development of metastases were 100% (60-100%) and 73% (53-87%), respectively. Our preliminary findings suggest that primary tumour blood flow might potentially be a useful predictor warranting further study. (orig.)

  13. [Seasonal changes in the blood coagulating and anticoagulating system indices in men at the preclinical stage of ischemic heart disease].

    Science.gov (United States)

    Andreenko, G V; Panchenko, V M; Liutova, L V; Lisina, A N; Karabasova, M A

    1980-03-01

    Examination of 52 males (aged 23 to 40 years) in the preclinical stage of ischemic heart disease revealed seasonal differences in the values of the blood coagulation and anticoagulation systems: in the spring, there was an increase in blood coagulation activity displayed by growth of the concentration of fibrinogen and soluble fibrin and a reduction in the amount of the plasminogen activator. The authors suggest conducting preventive treatment of patients in the spring, the most unfavourable season in respect of the effect of the pathogenetic factors.

  14. Hybridization and the Origin of Contagious Asexuality in Daphnia pulex

    OpenAIRE

    Xu, Sen; Spitze, Ken; Ackerman, Matthew S.; Ye, Zhiqiang; Bright, Lydia; Keith, Nathan; Jackson, Craig E.; Shaw, Joseph R.; Lynch, Michael

    2015-01-01

    Hybridization plays a potentially important role in the origin of obligate parthenogenesis (OP) in many organisms. However, it remains controversial whether hybridization directly triggers the transition from sexual reproduction to obligate asexuality or a hybrid genetic background enables asexual species to persist. Furthermore, we know little about the specific genetic elements from the divergent, yet still hybridizing lineages responsible for this transition and how these elements are furt...

  15. Red blood cell calcium homeostasis in patients with end-stage renal disease

    Energy Technology Data Exchange (ETDEWEB)

    Gafter, U.; Malachi, T.; Barak, H.; Djaldetti, M.; Levi, J. (Hasharon Hospital, Petah-Tiqva (Israel))

    1989-09-01

    Low cell calcium level is essential for preservation of red blood cell (RBC) membrane deformability and survival. RBCs from patients with end-stage renal disease (ESRD) demonstrate reduction in membrane deformability, possibly as a result of increased RBC cellular calcium level. To evaluate calcium homeostasis in RBCs from patients with ESRD, we measured cell calcium level, basal and calmodulin-stimulated calcium-stimulated Mg-dependent ATPase (CaATPase) activity, and calcium 45 efflux were measured before and after hemodialysis. The in vitro effect of uremic plasma and of urea on CaATPase activity of normal RBCs was tested, and 45Ca influx into RBCs of patients undergoing hemodialysis also was determined. A morphologic evaluation of red cells from patients with ESRD was performed with a scanning electron microscope. RBC calcium level in patients (mean +/- SEM 21.2 +/- 2.8 mumol/L of cells; n = 28) was higher than in controls (4.9 +/- 0.3 mumol/L of cells; n = 24; p less than 0.001). Hemodialysis had no effect on cell calcium level. Both basal and calmodulin-stimulated RBC CaATPase activities in patients with ESRD (n = 9) were reduced by approximately 50% (p less than 0.01), but after hemodialysis, enzyme activity returned to normal. 45Ca efflux from calcium-loaded cells, which was 2574.0 +/- 217.0 mumol/L of cells per 0.5 hours before hemodialysis, increased to 3140.7 +/- 206.8 mumol/L of cells per 0.5 hours after hemodialysis (p less than 0.005). In vitro incubation of normal RBCs with uremic plasma depressed CaATPase activity, but incubation with urea had no effect. RBCs of patients with ESRD revealed increased 45Ca influx, 7.63 +/- 1.15 mumol/L of cells per hour versus 4.61 +/- 0.39 mumol/L of cells per hour (p less than 0.025). RBCs of patients revealed a high incidence of spherocytosis and echynocytosis, which correlated with a high cell calcium level (r = 0.894, p less than 0.01).

  16. Stage-Specific Changes in Plasmodium Metabolism Required for Differentiation and Adaptation to Different Host and Vector Environments

    Science.gov (United States)

    Srivastava, Anubhav; Philip, Nisha; Hughes, Katie R.; Georgiou, Konstantina; MacRae, James I.; Barrett, Michael P.; McConville, Malcolm J.

    2016-01-01

    Malaria parasites (Plasmodium spp.) encounter markedly different (nutritional) environments during their complex life cycles in the mosquito and human hosts. Adaptation to these different host niches is associated with a dramatic rewiring of metabolism, from a highly glycolytic metabolism in the asexual blood stages to increased dependence on tricarboxylic acid (TCA) metabolism in mosquito stages. Here we have used stable isotope labelling, targeted metabolomics and reverse genetics to map stage-specific changes in Plasmodium berghei carbon metabolism and determine the functional significance of these changes on parasite survival in the blood and mosquito stages. We show that glutamine serves as the predominant input into TCA metabolism in both asexual and sexual blood stages and is important for complete male gametogenesis. Glutamine catabolism, as well as key reactions in intermediary metabolism and CoA synthesis are also essential for ookinete to oocyst transition in the mosquito. These data extend our knowledge of Plasmodium metabolism and point towards possible targets for transmission-blocking intervention strategies. Furthermore, they highlight significant metabolic differences between Plasmodium species which are not easily anticipated based on genomics or transcriptomics studies and underline the importance of integration of metabolomics data with other platforms in order to better inform drug discovery and design. PMID:28027318

  17. "In vitro" activity of gentian violet against asexual Plasmodium falciparum parasites

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    Shen Lin Yang

    1988-02-01

    Full Text Available In order to investigate whether gentian violet exhibited "in vitro" inhibitory activity against Plasmodium falciparum, the Authors have carried out 20 sensitivity tests according to the microtechnique described by RIECK MANN et al.5. Results have shown inhibition of schizonts'maturation at the following concentration: 1/1000; 1/1500; 1/2000; 1/2500; 1/3000 and 1/4000, thus demonstrating inhibitory activity of the tested dye against asexual blood parasites. The present data suggest gentain violet may be possibly used in the prophylaxis of transfusion-acquired malaria.

  18. Effect of artificial colloids on blood coagulation during shock stage of severe burn injury

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian-jun; XING Nan; CHEN Jiong; SHI Jian-wu; SU Guo-liang

    2013-01-01

    Background There are controversies about the use of artificial colloids.This research was aimed to determine the effect of various artificial colloids on blood coagulation in the shock stage of severe burn injury.Methods Totally,18 female Ba-Ma mini-pigs were subjected to a 40% total body surface third-degree flame burn under anesthesia.Resuscitation therapy was applied 2 hours after the injury,using the burn shock fluid resuscitation formula commonly accepted in the surgical treatment of burns.The Ba-Ma mini-pigs were randomly assigned to three groups (six pigs in each group):succinylated gelatin group (the artificial colloid used was succinylated gelatin Injection),hydroxyethyl starch group (the artificial colloid used was hydroxyethyl starch (130/0.4)),and allogeneic plasma group (the colloid used was allogeneic plasma).Blood samples were collected from the animals prior to the burn injury and again at intervals of 4,8,24 and 48 hours post-injury.The platelet count (PLT),prothrombin time (PT),international normalized ratio (INR),activated partial thromboplastin time (APTT),and fibrinogen (Fib) were measured,followed by a statistical analysis of all results.Results The PLT of succinylated gelatin group and hydroxyethyl starch group at intervals of 24 and 48 hours were (124.3±52.7),(78.8±16.4)×109/L and (159.0±62.8),(87.3±32.0)×109/L respectively.But in the allogeneic plasma group at intervals of 8,24,and 48 hours were (234.3±52.6),(136.0±47.4),(75.8±31.0)×109/L.The decrease were all statistically significant (P <0.05,P <0.01) when compared to pre-burn ((383.3±77.9),(382.7±65.7),(381.0±49.4)×109/L).The PLT among the three groups,at all the time points,had no statistical difference (P >0.05).Compared to pre-burn ((10.8±0.9),(11.4±0.8),(10.6±0.7) seconds),the PT of succinylated gelatin group and hydroxyethyl starch group at 24 hours were (14.5±1.5) and (16.2±1.3) seconds,whereas in the allogeneic plasma group at 8 and 24 hours the PT were

  19. Stage-selective inhibition of rodent malaria by cyclosporine.

    Science.gov (United States)

    Murphy, J R; Baqar, S; Baker, R H; Roberts, E; Nickell, S P; Cole, G A

    1988-01-01

    The relative susceptibility of different developmental stages of Plasmodium berghei to cyclosporine was investigated in vivo. Within 12 h of receiving a single 25-mg/kg (body weight) dose of cyclosporine, mice with patent P. berghei infections uniformly exhibited a rapid fall in asexual parasite stages. Initially, ring forms and mature schizonts disappeared. Subsequently, trophozoites disappeared between 21 and 24 h, whereas gametocytes persisted for 36 h. In contrast, when cyclosporine was administered to mice 1 day before inoculation (100 mg/kg) with P. berghei sporozoites and for 2 consecutive days after inoculation (25 mg/kg), infections developed normally. When mice with patent infections were placed on prolonged cyclosporine therapy (25 mg/kg per day), parasitemia initially disappeared but often recrudesced. Recrudescent parasites were frequently resistant to cyclosporine (Csr). The Csr phenotype remained stable after serial passage of parasites in mice and after transmission through Anopheles stephensi mosquitoes, in which the capacity to produce oocysts was reduced. When infections of untreated mice were initiated with equal numbers of Csr and cyclosporine-susceptible (Css) parasites and then carried through two serial cycles of mosquito-to-mouse transmission without cyclosporine treatment, the Csr phenotype was lost. The results indicate that cyclosporine selectively inhibits asexual blood stages of P. berghei and favors the emergence of Csr parasites with diminished infectivity for mosquitoes. PMID:3288113

  20. Public goods dilemma in asexual ant societies.

    Science.gov (United States)

    Dobata, Shigeto; Tsuji, Kazuki

    2013-10-01

    Cooperation in biological, social, and economic groups is underpinned by public goods that are generated by group members at some personal cost. Theory predicts that public goods will be exploited by cheaters who benefit from the goods by not paying for them, thereby leading to the collapse of cooperation. This situation, described as the "public goods dilemma" in game theory, makes the ubiquity of cooperation a major evolutionary puzzle. Despite this generalization, the demonstration of genetic background and fitness effects of the public goods dilemma has been limited to interactions between viruses and between cells, and thus its relevance at higher levels of organismal complexity is still largely unexplored. Here we provide experimental evidence for the public goods dilemma in a social insect, the ant Pristomyrmex punctatus. In this species, all workers are involved in both asexual reproduction and cooperative tasks. Genetic cheaters infiltrate field colonies, reproducing more than the workers but shunning cooperative tasks. In laboratory experiments, cheaters outcompeted coexisting workers in both survival and reproduction, although a group composed only of cheaters failed to produce offspring. The operations of the public goods dilemma in P. punctatus showed a remarkable convergence with those in microbial societies, not only in fitness consequences but also in behavioral mechanisms. Our study reinforces the evolutionary impact of cheaters on diverse cooperative systems in the laboratory and in the field.

  1. Chromosome length scaling in haploid, asexual reproduction

    Science.gov (United States)

    de Oliveira, P. M. C.

    2007-02-01

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size.

  2. Chromosome length scaling in haploid, asexual reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, P M C de [Instituto de Fisica, Universidade Federal Fluminense, avenida Litoranea s/n, Boa Viagem, Niteroi 24210-340 (Brazil)

    2007-02-14

    We study the genetic behaviour of a population formed by haploid individuals which reproduce asexually. The genetic information for each individual is stored along a bit-string (or chromosome) with L bits, where 0-bits represent the wild allele and 1-bits correspond to harmful mutations. Each newborn inherits this chromosome from its parent with a few random mutations: on average a fixed number m of bits are flipped. Selection is implemented according to the number N of 1-bits counted along the individual's chromosome: the smaller N the higher the probability an individual has to survive a new time step. Such a population evolves, with births and deaths, and its genetic distribution becomes stabilized after sufficiently many generations have passed. The question we pose concerns the procedure of increasing L. The aim is to get the same distribution of genetic loads N/L among the equilibrated population, in spite of a larger L. Should we keep the same mutation rate m/L for different values of L? The answer is yes, which intuitively seems to be plausible. However, this conclusion is not trivial, according to our simulation results: the question also involves the population size.

  3. Non-invasive assessment of pulmonary blood supply after staged repair of pulmonary atresia.

    OpenAIRE

    Del Torso, S.; Kelly, M J; Kalff, V; Stellin, G; Mee, R B; Venables, A W

    1985-01-01

    Radionuclide studies were performed to determine pulmonary blood flow in six children who had undergone surgery for pulmonary atresia, ventricular septal defect, and hypoplastic pulmonary arteries with or without major aortopulmonary collateral arteries. Lung blood flow was assessed from both particle perfusion lung scans and the pulmonary and systemic phase of a radionuclide dynamic flow study. Five patients had perfusion defects identified on the particle perfusion lung scan. In three of th...

  4. Clinical Observation in 45 Cases of Hemorrhagic Apoplexy of the Acute Stage Treated by Promoting Blood Circulation and Removing Blood Stasis

    Institute of Scientific and Technical Information of China (English)

    孙国柱

    2003-01-01

    To explore the therapeutic effects of the method of promoting blood circulation and removing blood stasis on hemorrhagic apoplexy of acute stage, 45 cases were treated by the method and observed for their conscious state and motor function, which were compared with 40 cases treated with regular western drugs. The results showed that the effective rate in the treated group was 82.2% and that in control group 60% with a significant difference (P<0.05) between the two groups. In the treated group, the scores of the conscious state and the motor function after treatment were elevated dramatically (P<0.01), indicating a much better effect in the treated group than in the control group.

  5. Botryllus schlosseri: a model ascidian for the study of asexual reproduction.

    Science.gov (United States)

    Manni, L; Zaniolo, G; Cima, F; Burighel, P; Ballarin, L

    2007-02-01

    Botryllus schlosseri, a cosmopolitan colonial ascidian reared in the laboratory for more than 50 years, reproduces both sexually and asexually and is used as a model organism for studying a variety of biological problems. Colonies are formed of numerous, genetically identical individuals (zooids) and undergo cyclical generation changes in which the adult zooids die and are replaced by their maturing buds. Because the progression of the colonial life cycle is intimately correlated with blastogenesis, a shared staging method of bud development is required to compare data coming from different laboratories. With the present review, we aim (1) to introduce B. schlosseri as a valuable chordate model to study various biological problems and, especially, sexual and asexual development; (2) to offer a detailed description of bud development up to adulthood and the attainment of sexual maturity; (3) to re-examine Sabbadin's (1955) staging method and re-propose it as a simple tool for in vivo recognition of the main morphogenetic events and recurrent changes in the blastogenetic cycle, as it refers to the developmental stages of buds and adults.

  6. Hepatitis C Virus Infection May Lead to Slower Emergence of P. falciparum in Blood

    Science.gov (United States)

    Ollomo, Benjamin; Mezui-Me-Ndong, Jérome; Noulin, Florian; Lachard, Isabelle; Ndong-Atome, Guy-Roger; Makuwa, Maria; Roques, Pierre; Branger, Michel; Preux, Pierre-Marie; Mazier, Dominique; Bisser, Sylvie

    2011-01-01

    Background Areas endemic for Plasmodium falciparum, hepatitis B virus (HBV) and hepatitis C virus (HCV) overlap in many parts of sub-Saharan Africa. HBV and HCV infections develop in the liver, where takes place the first development stage of P. falciparum before its further spread in blood. The complex mechanisms involved in the development of hepatitis may potentially influence the development of the liver stage of malaria parasites. Understanding the molecular mechanisms of these interactions could provide new pathophysiological insights for treatment strategies in Malaria. Methodology We studied a cohort of 319 individuals living in a village where the three infections are prevalent. The patients were initially given a curative antimalarial treatment and were then monitored for the emergence of asexual P. falciparum forms in blood, fortnightly for one year, by microscopy and polymerase chain reaction. Principal Findings At inclusion, 65 (20.4%) subjects had detectable malaria parasites in blood, 36 (11.3%) were HBV chronic carriers, and 61 (18.9%) were HCV chronic carriers. During follow-up, asexual P. falciparum forms were detected in the blood of 203 patients. The median time to P. falciparum emergence in blood was respectively 140 and 120 days in HBV- and HBV+ individuals, and 135 and 224 days in HCV- and HCV+ individuals. HCV carriage was associated with delayed emergence of asexual P. falciparum forms in blood relative to patients without HCV infection. Conclusions This pilot study represents first tentative evidence of a potential epidemiological interaction between HBV, HCV and P. falciparum infections. Age is an important confounding factor in this setting however multivariate analysis points to an interaction between P. falciparum and HCV at the hepatic level with a slower emergence of P. falciparum in HCV chronic carriers. More in depth analysis are necessary to unravel the basis of hepatic interactions between these two pathogens, which could help in

  7. Hepatitis C virus infection may lead to slower emergence of P. falciparum in blood.

    Directory of Open Access Journals (Sweden)

    Odile Ouwe-Missi-Oukem-Boyer

    Full Text Available BACKGROUND: Areas endemic for Plasmodium falciparum, hepatitis B virus (HBV and hepatitis C virus (HCV overlap in many parts of sub-Saharan Africa. HBV and HCV infections develop in the liver, where takes place the first development stage of P. falciparum before its further spread in blood. The complex mechanisms involved in the development of hepatitis may potentially influence the development of the liver stage of malaria parasites. Understanding the molecular mechanisms of these interactions could provide new pathophysiological insights for treatment strategies in Malaria. METHODOLOGY: We studied a cohort of 319 individuals living in a village where the three infections are prevalent. The patients were initially given a curative antimalarial treatment and were then monitored for the emergence of asexual P. falciparum forms in blood, fortnightly for one year, by microscopy and polymerase chain reaction. PRINCIPAL FINDINGS: At inclusion, 65 (20.4% subjects had detectable malaria parasites in blood, 36 (11.3% were HBV chronic carriers, and 61 (18.9% were HCV chronic carriers. During follow-up, asexual P. falciparum forms were detected in the blood of 203 patients. The median time to P. falciparum emergence in blood was respectively 140 and 120 days in HBV- and HBV+ individuals, and 135 and 224 days in HCV- and HCV+ individuals. HCV carriage was associated with delayed emergence of asexual P. falciparum forms in blood relative to patients without HCV infection. CONCLUSIONS: This pilot study represents first tentative evidence of a potential epidemiological interaction between HBV, HCV and P. falciparum infections. Age is an important confounding factor in this setting however multivariate analysis points to an interaction between P. falciparum and HCV at the hepatic level with a slower emergence of P. falciparum in HCV chronic carriers. More in depth analysis are necessary to unravel the basis of hepatic interactions between these two pathogens

  8. Male microchimerism at high levels in peripheral blood mononuclear cells from women with end stage renal disease before kidney transplantation.

    Directory of Open Access Journals (Sweden)

    Laetitia Albano

    Full Text Available Patients with end stage renal diseases (ESRD are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc, deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62% and quantities (98 genome equivalent cells per million of host cells, gEq/M of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, p<0.00001 and p = 0.0005 respectively. Male Mc was increased in women with ESRD whether they had or not a history of male pregnancy and/or of blood transfusion. Three out of five renal biopsies obtained a few years prior to the blood test also contained Mc, but no correlation could be established between earlier Mc in a kidney and later presence in PBMC. Finally, several years after female kidney transplantation, male Mc was totally cleared from PBMC in all women tested but one. This intriguing and striking initial result of natural and iatrogenic male Mc persistence in peripheral blood from women with ESRD raises several hypotheses for the possible role of these cells in renal diseases. Further studies are needed to elucidate mechanisms of recruitment and persistence of Mc in women with ESRD.

  9. Male microchimerism at high levels in peripheral blood mononuclear cells from women with end stage renal disease before kidney transplantation.

    Science.gov (United States)

    Albano, Laetitia; Rak, Justyna M; Azzouz, Doua F; Cassuto-Viguier, Elisabeth; Gugenheim, Jean; Lambert, Nathalie C

    2012-01-01

    Patients with end stage renal diseases (ESRD) are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc), deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC) from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62%) and quantities (98 genome equivalent cells per million of host cells, gEq/M) of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, ppregnancy and/or of blood transfusion. Three out of five renal biopsies obtained a few years prior to the blood test also contained Mc, but no correlation could be established between earlier Mc in a kidney and later presence in PBMC. Finally, several years after female kidney transplantation, male Mc was totally cleared from PBMC in all women tested but one. This intriguing and striking initial result of natural and iatrogenic male Mc persistence in peripheral blood from women with ESRD raises several hypotheses for the possible role of these cells in renal diseases. Further studies are needed to elucidate mechanisms of recruitment and persistence of Mc in women with ESRD.

  10. A Plasmodium vivax plasmid DNA- and adenovirus-vectored malaria vaccine encoding blood stage antigens AMA1 and MSP142 in a prime/boost heterologous immunization regimen partially protects Aotus monkeys against blood stage challenge.

    Science.gov (United States)

    Obaldia, Nicanor; Stockelman, Michael G; Otero, William; Cockrill, Jennifer A; Ganeshan, Harini; Abot, Esteban N; Zhang, Jianfeng; Limbach, Keith; Charoenvit, Yupin; Doolan, Denise L; Tang, De-Chu C; Richie, Thomas L

    2017-02-08

    Malaria is caused by parasites of the genus Plasmodium that are transmitted to humans by the bites of Anopheles mosquitoes. After the elimination of P. falciparum it is predicted that Plasmodium vivax will remain an important cause of morbidity and mortality outside of Africa, stressing the importance of developing a vaccine against malaria. In this study we assess the immunogenicity and protective efficacy of two P. vivax antigens, AMA1 and MSP142 in a recombinant DNA plasmid prime/adenoviral vector (Ad) boost regimen in Aotus monkeys. Groups of 4 to 5 monkeys were immunized with DNA alone, Ad alone, prime/boost regimens of each antigen, prime/boost with both antigens, and empty vector controls, and then subjected to blood stage challenge. The heterologous immunization regimen with the antigen pair was more protective than either antigen alone or both antigens delivered with a single vaccine platform, based on their ability to induced the longest pre-patent period and time to peak parasitemia; the lowest peak and mean parasitemia; the smallest area under the parasitemia curve and the highest self-cured rate. Overall, pre-challenge MSP1 antibody titers strongly correlated with decreased parasite burden. Nevertheless, a significant proportion of immunized animals developed anemia. In conclusion, P. vivax plasmid DNA/Ad5 vaccine encoding blood stage parasite antigens AMA1 and MSP142 in a heterologous prime/boost immunization regimen, provided significant protection against blood-stage challenge in Aotus monkeys, indicating the suitability of these antigens and regimen for further development.

  11. Autologous peripheral blood stem cell transplantation in tumor-stage mycosis fungoides: predictors of disease-free survival.

    Science.gov (United States)

    Russell-Jones, R; Child, F; Olavarria, E; Whittaker, S; Spittle, M; Apperley, J

    2001-09-01

    Nine patients with mycosis fungoides (age range 27-67) underwent autologous peripheral blood stem cell transplantation (PBSCT). All patients had tumor-stage disease, and four had lymph node involvement. Eight patients exhibited a peripheral blood T cell clone using PCR/SSCP analysis of the TCR gamma gene, six prior to harvest and two at the time of harvest. Mobilization of CD34+ stem cells was achieved with etoposide and G-CSF. Harvested cells were positively selected for CD34. After negative selection for CD4 and CD8, only two samples became PCR negative. Conditioning prior to reinfusion of stem cells was achieved with various combinations of total skin electron beam (TSEB), total body irradiation (TBI), and chemotherapy, depending upon the patient's prior exposure to radiotherapy. One patient failed to engraft and died of candidal septicemia 15 days posttransplant. The other eight patients achieved complete remission, but this was short-lived in four (median disease-free survival [DFS] = 2 months) and prolonged in three (median DFS 11 months). Those with a short DFS were distinguished by rapid tumor onset prior to transplant but not by stage at transplant. Loss of a detectable T cell clone after manipulation of the harvest did not discriminate between the two groups, but rapid relapsers had been subjected to a greater degree of T cell depletion, possibly indicating a compromised cytotoxic response post-PBSCT. The median survival of the cohort is four years from tumor onset, 15 months from PBSCT, and 27 months from the date a peripheral blood clone was first detected in the presence of tumor-stage disease. Rapid relapse was associated with poor overall survival. Our data demonstrate the value of PBSCT for inducing remission in tumor-stage mycosis fungoides. Reinfusion of neoplastic cells could be avoided by harvesting stem cells at an earlier stage in the disease process, preferably before a T cell clone is detectable in the peripheral blood. Alternatively T cell

  12. Interruption of the blood-stage cycle of the malaria parasite, Plasmodium chabaudi, by protein tyrosine kinase inhibitors

    Directory of Open Access Journals (Sweden)

    M.L. Gazarini

    2003-11-01

    Full Text Available Malaria is a devastating disease caused by a unicellular protozoan, Plasmodium, which affects 3.7 million people every year. Resistance of the parasite to classical treatments such as chloroquine requires the development of new drugs. To gain insight into the mechanisms that control Plasmodium cell cycle, we have examined the effects of kinase inhibitors on the blood-stage cycle of the rodent malaria parasite, Plasmodium chabaudi. In vitro incubation of red blood cells for 17 h at 37ºC with the inhibitors led to a decrease in the percent of infected cells, compared to control treatment, as follows: genistein (200 µM - 75%, staurosporine (1 µM - 58%, R03 (1 µM - 75%, and tyrphostins B44 (100 µM - 66% and B46 (100 µM - 68%. All these treatments were shown to retard or prevent maturation of the intraerythrocytic parasites. The diverse concentration ranges at which these inhibitors exert their effects give a clue as to the types of signals that initiate the transitions between the different developmental stages of the parasite. The present data support our hypothesis that the maturation of the intraerythrocytic cycle of malaria parasites requires phosphorylation. In this respect, we have recently reported a high Ca2+ microenvironment surrounding the parasite within red blood cells. Several kinase activities are modulated by Ca2+. The molecular identification of the targets of these kinases could provide new strategies against malaria.

  13. Biological markers of asexuality: Handedness, birth order, and finger length ratios in self-identified asexual men and women.

    Science.gov (United States)

    Yule, Morag A; Brotto, Lori A; Gorzalka, Boris B

    2014-02-01

    Human asexuality is defined as a lack of sexual attraction to anyone or anything and it has been suggested that it may be best conceptualized as a sexual orientation. Non-right-handedness, fraternal birth order, and finger length ratio (2D:4D) are early neurodevelopmental markers associated with sexual orientation. We conducted an Internet study investigating the relationship between self-identification as asexual, handedness, number of older siblings, and self-measured finger-lengths in comparison to individuals of other sexual orientation groups. A total of 325 asexuals (60 men and 265 women; M age, 24.8 years), 690 heterosexuals (190 men and 500 women; M age, 23.5 years), and 268 non-heterosexuals (homosexual and bisexual; 64 men and 204 women; M age, 29.0 years) completed online questionnaires. Asexual men and women were 2.4 and 2.5 times, respectively, more likely to be non-right-handed than their heterosexual counterparts and there were significant differences between sexual orientation groups in number of older brothers and older sisters, and this depended on handedness. Asexual and non-heterosexual men were more likely to be later-born than heterosexual men, and asexual women were more likely to be earlier-born than non-heterosexual women. We found no significant differences between sexual orientation groups on measurements of 2D:4D ratio. This is one of the first studies to test and provide preliminary empirical support for an underlying neurodevelopmental basis to account for the lack of sexual attraction characteristic of asexuality.

  14. Hybridization and the Origin of Contagious Asexuality in Daphnia pulex

    Science.gov (United States)

    Xu, Sen; Spitze, Ken; Ackerman, Matthew S.; Ye, Zhiqiang; Bright, Lydia; Keith, Nathan; Jackson, Craig E.; Shaw, Joseph R.; Lynch, Michael

    2015-01-01

    Hybridization plays a potentially important role in the origin of obligate parthenogenesis (OP) in many organisms. However, it remains controversial whether hybridization directly triggers the transition from sexual reproduction to obligate asexuality or a hybrid genetic background enables asexual species to persist. Furthermore, we know little about the specific genetic elements from the divergent, yet still hybridizing lineages responsible for this transition and how these elements are further spread to create other OP lineages. In this study, we address these questions in Daphnia pulex, where cyclically parthenogenetic (CP) and OP lineages coexist. Ancestry estimates and whole-genome association mapping using 32 OP isolates suggest that a complex hybridization history between the parental species D. pulex and D. pulicaria is responsible for the introgression of a set of 647 D. pulicaria single nucleotide polymorphism alleles that show perfect association with OP. Crossing experiments using males of OP lineages and females of CP lineages strongly support a polygenic basis for OP. Single-sperm analyses show that although normal meiotic recombination occurs in the production of haploid sperm by males of OP lineages, a significant proportion of such sperm are polyploid, suggesting that the spread of asexual elements through these males (i.e., contagious asexuality) is much less efficient than previously envisioned. Although the current Daphnia genome annotation does not provide mechanistic insight into the nature of the asexuality-associated alleles, these alleles should be considered as candidates for future investigations on the genetic underpinnings of OP. PMID:26351296

  15. Coevolution of robustness, epistasis, and recombination favors asexual reproduction.

    Science.gov (United States)

    MacCarthy, Thomas; Bergman, Aviv

    2007-07-31

    The prevalence of sexual reproduction remains one of the most perplexing phenomena in evolutionary biology. The deterministic mutation hypothesis postulates that sexual reproduction will be advantageous under synergistic epistasis, a condition in which mutations cause a greater reduction in fitness when combined than would be expected from their individual effects. The inverse condition, antagonistic epistasis, correspondingly is predicted to favor asexual reproduction. To assess this hypothesis, we introduce a finite population evolutionary process that combines a recombination modifier formalism with a gene-regulatory network model. We demonstrate that when reproductive mode and epistasis are allowed to coevolve, asexual reproduction outcompetes sexual reproduction. In addition, no correlation is found between the level of synergistic epistasis and the fixation time of the asexual mode. However, a significant correlation is found between the level of antagonistic epistasis and asexual mode fixation time. This asymmetry can be explained by the greater reduction in fitness imposed by sexual reproduction as compared with asexual reproduction. Our findings present evidence and suggest plausible explanations that challenge both the deterministic mutation hypothesis and recent arguments asserting the importance of emergent synergistic epistasis in the maintenance of sexual reproduction.

  16. Hybridization and the Origin of Contagious Asexuality in Daphnia pulex.

    Science.gov (United States)

    Xu, Sen; Spitze, Ken; Ackerman, Matthew S; Ye, Zhiqiang; Bright, Lydia; Keith, Nathan; Jackson, Craig E; Shaw, Joseph R; Lynch, Michael

    2015-12-01

    Hybridization plays a potentially important role in the origin of obligate parthenogenesis (OP) in many organisms. However, it remains controversial whether hybridization directly triggers the transition from sexual reproduction to obligate asexuality or a hybrid genetic background enables asexual species to persist. Furthermore, we know little about the specific genetic elements from the divergent, yet still hybridizing lineages responsible for this transition and how these elements are further spread to create other OP lineages. In this study, we address these questions in Daphnia pulex, where cyclically parthenogenetic (CP) and OP lineages coexist. Ancestry estimates and whole-genome association mapping using 32 OP isolates suggest that a complex hybridization history between the parental species D. pulex and D. pulicaria is responsible for the introgression of a set of 647 D. pulicaria single nucleotide polymorphism alleles that show perfect association with OP. Crossing experiments using males of OP lineages and females of CP lineages strongly support a polygenic basis for OP. Single-sperm analyses show that although normal meiotic recombination occurs in the production of haploid sperm by males of OP lineages, a significant proportion of such sperm are polyploid, suggesting that the spread of asexual elements through these males (i.e., contagious asexuality) is much less efficient than previously envisioned. Although the current Daphnia genome annotation does not provide mechanistic insight into the nature of the asexuality-associated alleles, these alleles should be considered as candidates for future investigations on the genetic underpinnings of OP.

  17. Ontology-based Malaria Parasite Stage and Species Identification from Peripheral Blood Smear Images

    NARCIS (Netherlands)

    Makkapati, V.; Rao, R.

    2011-01-01

    The diagnosis and treatment of malaria infection requires detectingthe presence of malaria parasite in the patient as well as identification of the parasite species. We present an image processing-basedapproach to detect parasites in microscope images of blood smear andan ontology-based classificati

  18. Longitudinal observations on circadian blood pressure variation in chronic kidney disease stages 3-5

    DEFF Research Database (Denmark)

    Elung-Jensen, Thomas; Strandgaard, Svend; Kamper, Anne-Lise

    2008-01-01

    BACKGROUND: It has been suggested that status as a 'non-dipper' determined from 24-h blood pressure (BP) recordings is associated with increased risk of end-organ damage but little is known about the consistency of dipper status in renal patients. The present post hoc analysis evaluated dipper...

  19. Efficacy of combination therapy with amlodipine besylate/benazepril hydrochloride for lowering systolic blood pressure in stage 2 hypertension.

    Science.gov (United States)

    Neutel, Joel M; Smith, David H G; Weber, Michael A; Schofield, Lesley; Purkayastha, Das; Gatlin, Marjorie

    2006-01-01

    The Systolic Evaluation of Lotrel Efficacy and Comparative Therapies (SELECT) study compared daily treatment with combination amlodipine besylate/benazepril hydrochloride 5/20 mg, amlodipine besylate 5 mg, and benazepril hydrochloride 20 mg in 505 patients aged 55 years of age or older with stage 2 hypertension (systolic blood pressure [BP] > or =160 and or =60 and < or =100 mm Hg). BP and pulse pressure were assessed by conventional office BP measurements and 24-hour ambulatory BP monitoring. In this analysis, combination therapy was associated with significantly greater reductions in mean 24-hour BP, pulse pressure, and mean ambulatory BP during various time intervals compared with either monotherapy in the intent-to-treat population, in those with isolated and predominantly systolic hypertension, and in dippers and nondippers. Adverse event rates were low and similar in all treatment groups. This study demonstrated that combination therapy is superior to monotherapy in older patients with stage 2 systolic hypertension and is well tolerated.

  20. [Early stages of development of Trypanosoma rotatorium (Mayer, 1843) from peripheral blood and internal organs of Anurans Bufo bufo (Linnaeus) and Rana sp. (Anura)].

    Science.gov (United States)

    Malysheva, M N

    2014-01-01

    The data on the fauna of trypanosomes of Anura of the Leningrad Province are given. The initial development stages of Trypanosoma rotatorium in peripheral blood and internal organs of the frog are described for the first time.

  1. Coexistence of sexual individuals and genetically isolated asexual counterparts in a thrips.

    OpenAIRE

    Kazuya Kobayashi; Jin Yoshimura; Eisuke Hasegawa

    2013-01-01

    Sex is a paradoxical phenomenon because it is less efficient compared with asexual reproduction. To resolve this paradox we need a direct comparison between sexual and asexual forms. In many organisms, however, sexual and asexual forms do not occur in the same habitat, or at the same time. In a few cases where sexual and asexual forms are found in a single population, some (though rare) genetic exchange is usually detected between the two forms. When genetic exchange occurs a direct compariso...

  2. What Asexuality Contributes to the Same-Sex Marriage Discussion.

    Science.gov (United States)

    Scherrer, Kristin S

    2010-01-01

    While same-sex marriage debates have captured public attention, it is but one component of a broader discussion regarding the role of marriage in a changing society. To inform this discussion, I draw on qualitative, Internet survey data from 102 self-identified asexual individuals. I find that asexual relationships are complicated and nuanced in ways that have implications for a GLBTQ political agenda, including same-sex marriage recognition. In addition, findings indicate that assumptions of sex and sexuality in relationships are problematic and that present language for describing relationships is limiting. Findings suggest a social justice agenda for marginalized sexualities should be broader in scope than same-sex marriage.

  3. [The diagnosis, treatment and prevention of early stages of cerebral blood flow insufficiency].

    Science.gov (United States)

    Martynov, Iu S; Girich, T I; Kuntsevich, G I; Sokov, E L; Malkova, E V; Borisova, N F; Nozdriukhina, N V; Shuvakhina, N A

    1998-01-01

    Biomicroscopy of bulbar conjuctiva as well as oencephalography were quite informative for discovery of subclinical manifestations of disorders of cerebral circulation (DCC). That conclusion resulted from the observation of 133 patients with early forms of vascular pathology of brain. Besides, to find the early signs, it was also worth while to perform some biochemical studies (coagulogram, studies of both rheologic properties and lipids of blood). In order to establish discirculatory encephalopathy it was also expedient to use ultrasonic dopplerography and electroencephalography. Efficiency of some medical-prophylactic measures (normalization of the diet, weight, muscular activity, administration of antiatherosclerotic drugs) that prevented the progression of aorta's stenosis was also demonstrated.

  4. What can asexual lineage age tell us about the maintenance of sex?

    Science.gov (United States)

    Neiman, Maurine; Meirmans, Stephanie; Meirmans, Patrick G

    2009-06-01

    Sexual reproduction is both extremely costly and extremely common relative to asexuality, indicating that it must confer profound benefits. This in turn points to major disadvantages of asexual reproduction, which is usually given as an explanation for why almost all asexual lineages are apparently quite short-lived. However, a growing body of evidence suggests that some asexual lineages are actually quite old. Insight into why sex is so common may come from understanding why asexual lineages persist in some places or taxa but not others. Here, we review the distribution of asexual lineage ages estimated from a diverse array of taxa, and we discuss our results in light of the main mutational and environmental hypotheses for sex. Along with strengthening the case for wide variation in asexual lineage age and the existence of many old asexual taxa, we also found that the distribution of asexual lineage age estimates follows a surprisingly regular distribution, to the extent that asexual taxa viewed as "scandalously" ancient merely fall on the high end of this distribution. We interpret this result to mean that similar mechanisms may determine asexual lineage age across eukaryotic taxa. We also derive some qualitative predictions for asexual lineage age under different theories for sex and discuss empirical evidence for these predictions. Ultimately, we were limited in the extent to which we could use these data to make inferences about the maintenance of sex by the absence of both clear theoretical expectations and estimates of key parameters.

  5. Evidence for an amoeba-like infectious stage of ichthyophonus sp. and description of a circulating blood stage: a probable mechanism for dispersal within the fish host

    Science.gov (United States)

    Kocan, Richard; LaPatra, Scott; Hershberger, Paul

    2013-01-01

    Small amoeboid cells, believed to be the infectious stage of Ichthyophonus sp., were observed in the bolus (stomach contents) and tunica propria (stomach wall) of Pacific staghorn sculpins and rainbow trout shortly after they ingested Ichthyophonus sp.–infected tissues. By 24–48 hr post-exposure (PE) the parasite morphed from the classically reported multinucleate thick walled schizonts to 2 distinct cell types, i.e., a larger multinucleate amoeboid cell surrounded by a narrow translucent zone and a smaller spherical cell surrounded by a “halo” and resembling a small schizont. Both cell types also appeared in the tunica propria, indicating that they had recently penetrated the columnar epithelium of the stomach. No Ichthyophonus sp. pseudo-hyphae (“germination tubes”) were observed in the bolus or penetrating the stomach wall. Simultaneously, Ichthyophonus sp. was isolated in vitro from aortic blood, which was consistently positive from 6 to 144 hr PE, then only intermittently for the next 4 wk. Small PAS-positive cells observed in blood cultures grew into colonies consisting of non-septate tubules (pseudo-hyphae) terminating in multinucleated knob-like apices similar to those seen in organ explant cultures. Organ explants were culture positive every day; however, typical Ichthyophonus sp. schizonts were not observed histologically until 20–25 days PE. From 20 to 60 days PE, schizont diameter increased from ≤25 μm to ≥82 μm. Based on the data presented herein, we are confident that we have resolved the life cycle of Ichthyophonus sp. within the piscivorous host.

  6. Polymorphisms in B Cell Co-Stimulatory Genes Are Associated with IgG Antibody Responses against Blood-Stage Proteins of Plasmodium vivax.

    Directory of Open Access Journals (Sweden)

    Gustavo C Cassiano

    Full Text Available The development of an effective immune response can help decrease mortality from malaria and its clinical symptoms. However, this mechanism is complex and has significant inter-individual variation, most likely owing to the genetic contribution of the human host. Therefore, this study aimed to investigate the influence of polymorphisms in genes involved in the costimulation of B-lymphocytes in the naturally acquired humoral immune response against proteins of the asexual stage of Plasmodium vivax. A total of 319 individuals living in an area of malaria transmission in the Brazilian Amazon were genotyped for four SNPs in the genes CD40, CD40L, BLYS and CD86. In addition, IgG antibodies against P. vivax apical membrane antigen 1 (PvAMA-1, Duffy binding protein (PvDBP and merozoite surface protein 1 (PvMSP-119 were detected by ELISA. The SNP BLYS -871C>T was associated with the frequency of IgG responders to PvAMA-1 and PvMSP-119. The SNP CD40 -1C>T was associated with the IgG response against PvDBP, whereas IgG antibody titers against PvMSP-119 were influenced by the polymorphism CD86 +1057G>A. These data may help to elucidate the immunological aspects of vivax malaria and consequently assist in the design of malaria vaccines.

  7. [The comparison of concentration of endogenous ethanol blood serum in alcoholics and in non-alcoholics at different stages of abstinence].

    Science.gov (United States)

    Lukaszewicz, A; Markowski, T; Pawlak, D

    1997-01-01

    In this report the concentration of endogenous ethanol in blood serum in alcoholics at different stages of abstinence and in non-alcoholics was studied. 36 people--26 alcoholics and 10 non-alcoholics were examined and gas chromatography was used. It was revealed that the longer the period of abstinence in alcoholics, the lower the concentration of endogenous ethanol in blood serum. Moreover, the alcoholics showed a higher concentration of endogenous ethanol in blood serum as compared to non-alcoholics.

  8. Improving blood pressure control in end stage renal disease through a supportive educative nursing intervention.

    Science.gov (United States)

    Kauric-Klein, Zorica

    2012-01-01

    Hypertension in patients on hemodialysis (HD) contributes significantly to their morbidity and mortality. This study examined whether a supportive nursing intervention incorporating monitoring, goal setting, and reinforcement can improve blood pressure (BP) control in a chronic HD population. A randomized controlled design was used and 118 participants were recruited from six HD units in the Detroit metro area. The intervention consisted of (1) BP education sessions; (2) a 12-week intervention, including monitoring, goal setting, and reinforcement; and (3) a 30-day post-intervention follow-up period. Participants in the treatment were asked to monitor their BP, sodium, and fluid intake weekly for 12 weeks in weekly logs. BP, fluid and sodium logs were reviewed weekly with the researcher to determine if goals were met or not met. Reinforcement was given for goals met and problem solving offered when goals were not met. The control group received standard care. Both systolic and diastolic BPs were significantly decreased in the treatment group.

  9. Distinct kinetics of memory B-cell and plasma-cell responses in peripheral blood following a blood-stage Plasmodium chabaudi infection in mice.

    Directory of Open Access Journals (Sweden)

    Eunice W Nduati

    Full Text Available B cell and plasma cell responses take place in lymphoid organs, but because of the inaccessibility of these organs, analyses of human responses are largely performed using peripheral blood mononuclear cells (PBMC. To determine whether PBMC are a useful source of memory B cells and plasma cells in malaria, and whether they reflect Plasmodium-specific B cell responses in spleen or bone marrow, we have investigated these components of the humoral response in PBMC using a model of Plasmodium chabaudi blood-stage infections in C57BL/6 mice. We detected memory B cells, defined as isotype-switched IgD(- IgM(- CD19(+ B cells, and low numbers of Plasmodium chabaudi Merozoite Surface Protein-1 (MSP1-specific memory B cells, in PBMC at all time points sampled for up to 90 days following primary or secondary infection. By contrast, we only detected CD138(+ plasma cells and MSP1-specific antibody-secreting cells within a narrow time frame following primary (days 10 to 25 or secondary (day 10 infection. CD138(+ plasma cells in PBMC at these times expressed CD19, B220 and MHC class II, suggesting that they were not dislodged bone-marrow long-lived plasma cells, but newly differentiated migratory plasmablasts migrating to the bone marrow; thus reflective of an ongoing or developing immune response. Our data indicates that PBMC can be a useful source for malaria-specific memory B cells and plasma cells, but extrapolation of the results to human malaria infections suggests that timing of sampling, particularly for plasma cells, may be critical. Studies should therefore include multiple sampling points, and at times of infection/immunisation when the B-cell phenotypes of interest are likely to be found in peripheral blood.

  10. Deleterious Mutation Accumulation in Asexual Timema Stick Insects

    NARCIS (Netherlands)

    Henry, Lee; Schwander, Tanja; Crespi, Bernard J.

    2012-01-01

    Sexual reproduction is extremely widespread in spite of its presumed costs relative to asexual reproduction, indicating that it must provide significant advantages. One postulated benefit of sex and recombination is that they facilitate the purging of mildly deleterious mutations, which would accumu

  11. Increased red blood cell distribution width associates with cancer stage and prognosis in patients with lung cancer.

    Directory of Open Access Journals (Sweden)

    Yasuko Koma

    Full Text Available BACKGROUND: Red cell distribution width (RDW, one of many routinely examined parameters, shows the heterogeneity in erythrocyte size. We investigated the association of RDW levels with clinical parameters and prognosis of lung cancer patients. METHODS: Clinical and laboratory data from 332 patients with lung cancer in a single institution were retrospectively studied by univariate analysis. Kaplan-Meier survival analysis and Cox proportional hazard models were used to examine the effect of RDW on survival. RESULTS: THE RDW LEVELS WERE DIVIDED INTO TWO GROUPS: high RDW (>=15%, n=73 vs. low RDW, n=259 (<15%. Univariate analysis showed that there were significant associations of high RDW values with cancer stage, performance status, presence of other disease, white blood cell count, hemoglobin, mean corpuscular volume, platelet count, albumin level, C-reactive protein level, and cytokeratin 19 fragment level. Kruskal-Wallis tests revealed an association of RDW values with cancer stage in patients irrespective of comorbidity (patient with/without comorbidity: p<0.0001, patient without comorbidity: p<0.0001. Stages I-IV lung cancer patients with higher RDW values had poorer prognoses than those with lower RDW values (Wilcoxon test: p=0.002. In particular, the survival rates of stage I and II patients (n=141 were lower in the high RDW group (n=19 than in the low RDW group (n=122 (Wilcoxon test: p<0.001. Moreover, multivariate analysis showed higher RDW is a significant prognostic factor (p=0.040. CONCLUSION: RDW is associated with several factors that reflect inflammation and malnutrition in lung cancer patients. Moreover, high levels of RDW are associated with poor survival. RDW might be used as a new and convenient marker to determine a patient's general condition and to predict the mortality risk of lung cancer patients.

  12. IPP-rich milk protein hydrolysate lowers blood pressure in subjects with stage 1 hypertension, a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kloek Joris

    2010-11-01

    Full Text Available Abstract Background Milk derived peptides have been identified as potential antihypertensive agents. The primary objective was to investigate the effectiveness of IPP-rich milk protein hydrolysates (MPH on reducing blood pressure (BP as well as to investigate safety parameters and tolerability. The secondary objective was to confirm or falsify ACE inhibition as the mechanism underlying BP reductions by measuring plasma renin activity and angiotensin I and II. Methods We conducted a randomized, placebo-controlled, double blind, crossover study including 70 Caucasian subjects with prehypertension or stage 1 hypertension. Study treatments consisted of daily consumption of two capsules MPH1 (each containing 7.5 mg Isoleucine-Proline-Proline; IPP, MPH2 (each containing 6.6 mg Methionine-Alanine-Proline, 2.3 mg Leucine-Proline-Proline, 1.8 mg IPP, or placebo (containing cellulose for 4 weeks. Results In subjects with stage 1 hypertension, MPH1 lowered systolic BP by 3.8 mm Hg (P = 0.0080 and diastolic BP by 2.3 mm Hg (P = 0.0065 compared with placebo. In prehypertensive subjects, the differences in BP between MPH1 and placebo were not significant. MPH2 did not change BP significantly compared with placebo in stage I hypertensive or prehypertensive subjects. Intake of MPHs was well tolerated and safe. No treatment differences in hematology, clinical laboratory parameters or adverse effects were observed. No significant differences between MPHs and placebo were found in plasma renin activity, or angiotensin I and II. Conclusions MPH1, containing IPP and no minerals, exerts clinically relevant BP lowering effects in subjects with stage 1 hypertension. It may be included in lifestyle changes aiming to prevent or reduce high BP. Trial registration ClinicalTrials.gov NCT00471263

  13. Bacterial symbiosis maintenance in the asexually reproducing and regenerating flatworm Paracatenula galateia.

    Science.gov (United States)

    Dirks, Ulrich; Gruber-Vodicka, Harald R; Leisch, Nikolaus; Bulgheresi, Silvia; Egger, Bernhard; Ladurner, Peter; Ott, Jörg A

    2012-01-01

    Bacteriocytes set the stage for some of the most intimate interactions between animal and bacterial cells. In all bacteriocyte possessing systems studied so far, de novo formation of bacteriocytes occurs only once in the host development, at the time of symbiosis establishment. Here, we present the free-living symbiotic flatworm Paracatenula galateia and its intracellular, sulfur-oxidizing bacteria as a system with previously undescribed strategies of bacteriocyte formation and bacterial symbiont transmission. Using thymidine analogue S-phase labeling and immunohistochemistry, we show that all somatic cells in adult worms - including bacteriocytes - originate exclusively from aposymbiotic stem cells (neoblasts). The continued bacteriocyte formation from aposymbiotic stem cells in adult animals represents a previously undescribed strategy of symbiosis maintenance and makes P. galateia a unique system to study bacteriocyte differentiation and development. We also provide morphological and immunohistochemical evidence that P. galateia reproduces by asexual fragmentation and regeneration (paratomy) and, thereby, vertically transmits numerous symbiont-containing bacteriocytes to its asexual progeny. Our data support the earlier reported hypothesis that the symbiont population is subjected to reduced bottleneck effects. This would justify both the codiversification between Paracatenula hosts and their Candidatus Riegeria symbionts, and the slow evolutionary rates observed for several symbiont genes.

  14. Cryptic species in putative ancient asexual darwinulids (Crustacea, Ostracoda.

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    Isa Schön

    Full Text Available BACKGROUND: Fully asexually reproducing taxa lack outcrossing. Hence, the classic Biological Species Concept cannot be applied. METHODOLOGY/PRINCIPAL FINDINGS: We used DNA sequences from the mitochondrial COI gene and the nuclear ITS2 region to check species boundaries according to the evolutionary genetic (EG species concept in five morphospecies in the putative ancient asexual ostracod genera, Penthesilenula and Darwinula, from different continents. We applied two methods for detecting cryptic species, namely the K/θ method and the General Mixed Yule Coalescent model (GMYC. We could confirm the existence of species in all five darwinulid morphospecies and additional cryptic diversity in three morphospecies, namely in Penthesilenula brasiliensis, Darwinula stevensoni and in P. aotearoa. The number of cryptic species within one morphospecies varied between seven (P. brasiliensis, five to six (D. stevensoni and two (P. aotearoa, respectively, depending on the method used. Cryptic species mainly followed continental distributions. We also found evidence for coexistence at the local scale for Brazilian cryptic species of P. brasiliensis and P. aotearoa. Our ITS2 data confirmed that species exist in darwinulids but detected far less EG species, namely two to three cryptic species in P. brasiliensis and no cryptic species at all in the other darwinulid morphospecies. CONCLUSIONS/SIGNIFICANCE: Our results clearly demonstrate that both species and cryptic diversity can be recognized in putative ancient asexual ostracods using the EG species concept, and that COI data are more suitable than ITS2 for this purpose. The discovery of up to eight cryptic species within a single morphospecies will significantly increase estimates of biodiversity in this asexual ostracod group. Which factors, other than long-term geographic isolation, are important for speciation processes in these ancient asexuals remains to be investigated.

  15. Blood

    Science.gov (United States)

    ... Also, blood is either Rh-positive or Rh-negative. So if you have type A blood, it's either A positive or A negative. Which type you are is important if you need a blood transfusion. And your Rh factor could be important ...

  16. Preoperative Monocyte-to-Lymphocyte Ratio in Peripheral Blood Predicts Stages, Metastasis, and Histological Grades in Patients with Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Jiangdong Xiang

    2017-02-01

    dehydrogenase were found between the low-MLR group (MLR ≤ 0.23 and the high-MLR group (MLR > 0.23. Correspondingly, dramatic differences were observed between the two groups in OS. CONCLUSION: Our results show that the peripheral blood MLR before surgery could be a significant predictor of advanced stages, advanced pathologic grades, and positive lymphatic metastasis in ovarian cancer patients.

  17. Nucleated red blood cells and early EEG: predicting Sarnat stage and two year outcome.

    LENUS (Irish Health Repository)

    Walsh, B H

    2012-01-31

    AIMS: Hypoxic Ischaemic Encephalopathy (HIE) causes characteristic changes of the electroencephalogram (EEG), and a raised Nucleated Red Blood Cell (NRBC) count compared to controls. We wished to examine whether combining these markers could improve their ability to predict HIE severity in the first 24h. METHODS: Term infants with HIE were recruited. NRBC count and continuous multi-channel EEG were recorded within the first 24h. Neurological assessment was carried out at 24 months. A control population with NRBC counts in the first 24h was recruited. RESULTS: 44 infants with HIE and 43 control infants were recruited. Of the HIE population 39 completed a 2 year follow-up. The median NRBC count differed significantly between the controls and those with HIE (3\\/100 WBC [range of 0-11] vs 12.3\\/100 WBC [0-240]) (p<0.001). Within the HIE population the median NRBC count was significantly greater in infants with moderate\\/severe HIE than mild (16\\/100 WBC [range of 0-240] vs 8\\/100 WBC [1-23]) (p=0.016), and among infants with abnormal outcome compared to normal (21.3\\/100 WBC [1-239.8] vs 8.3\\/100 WBC [0-50])(p=0.03). The predictive ability of EEG changed with time post-delivery, therefore results are given at both 12 and 24h of age. At both time points the combined marker had a stronger correlation than EEG alone; with HIE severity (12h: r=0.661 vs r=0.622), (24h: r=0.645 vs r=0.598), and with outcome at 2 years (12h: r=0.756 vs r=0.652), (24h: r=0.802 vs r=0.746). CONCLUSION: Combining early EEG and NRBC count to predict HIE severity and neurological outcome, improved the predictive ability of either in isolation.

  18. CD8+ T cells from a novel T cell receptor transgenic mouse induce liver-stage immunity that can be boosted by blood-stage infection in rodent malaria.

    Science.gov (United States)

    Lau, Lei Shong; Fernandez-Ruiz, Daniel; Mollard, Vanessa; Sturm, Angelika; Neller, Michelle A; Cozijnsen, Anton; Gregory, Julia L; Davey, Gayle M; Jones, Claerwen M; Lin, Yi-Hsuan; Haque, Ashraful; Engwerda, Christian R; Nie, Catherine Q; Hansen, Diana S; Murphy, Kenneth M; Papenfuss, Anthony T; Miles, John J; Burrows, Scott R; de Koning-Ward, Tania; McFadden, Geoffrey I; Carbone, Francis R; Crabb, Brendan S; Heath, William R

    2014-05-01

    To follow the fate of CD8+ T cells responsive to Plasmodium berghei ANKA (PbA) infection, we generated an MHC I-restricted TCR transgenic mouse line against this pathogen. T cells from this line, termed PbT-I T cells, were able to respond to blood-stage infection by PbA and two other rodent malaria species, P. yoelii XNL and P. chabaudi AS. These PbT-I T cells were also able to respond to sporozoites and to protect mice from liver-stage infection. Examination of the requirements for priming after intravenous administration of irradiated sporozoites, an effective vaccination approach, showed that the spleen rather than the liver was the main site of priming and that responses depended on CD8α+ dendritic cells. Importantly, sequential exposure to irradiated sporozoites followed two days later by blood-stage infection led to augmented PbT-I T cell expansion. These findings indicate that PbT-I T cells are a highly versatile tool for studying multiple stages and species of rodent malaria and suggest that cross-stage reactive CD8+ T cells may be utilized in liver-stage vaccine design to enable boosting by blood-stage infections.

  19. Biosynthesis of GDP-fucose and other sugar nucleotides in the blood stages of Plasmodium falciparum.

    Science.gov (United States)

    Sanz, Sílvia; Bandini, Giulia; Ospina, Diego; Bernabeu, Maria; Mariño, Karina; Fernández-Becerra, Carmen; Izquierdo, Luis

    2013-06-01

    Carbohydrate structures play important roles in many biological processes, including cell adhesion, cell-cell communication, and host-pathogen interactions. Sugar nucleotides are activated forms of sugars used by the cell as donors for most glycosylation reactions. Using a liquid chromatography-tandem mass spectrometry-based method, we identified and quantified the pools of UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, GDP-mannose, and GDP-fucose in Plasmodium falciparum intraerythrocytic life stages. We assembled these data with the in silico functional reconstruction of the parasite metabolic pathways obtained from the P. falciparum annotated genome, exposing new active biosynthetic routes crucial for further glycosylation reactions. Fucose is a sugar present in glycoconjugates often associated with recognition and adhesion events. Thus, the GDP-fucose precursor is essential in a wide variety of organisms. P. falciparum presents homologues of GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase enzymes that are active in vitro, indicating that most GDP-fucose is formed by a de novo pathway that involves the bioconversion of GDP-mannose. Homologues for enzymes involved in a fucose salvage pathway are apparently absent in the P. falciparum genome. This is in agreement with in vivo metabolic labeling experiments showing that fucose is not significantly incorporated by the parasite. Fluorescence microscopy of epitope-tagged versions of P. falciparum GDP-mannose 4,6-dehydratase and GDP-L-fucose synthase expressed in transgenic 3D7 parasites shows that these enzymes localize in the cytoplasm of P. falciparum during the intraerythrocytic developmental cycle. Although the function of fucose in the parasite is not known, the presence of GDP-fucose suggests that the metabolite may be used for further fucosylation reactions.

  20. IFNAR1-Signalling Obstructs ICOS-mediated Humoral Immunity during Non-lethal Blood-Stage Plasmodium Infection

    Science.gov (United States)

    Sebina, Ismail; James, Kylie R.; Soon, Megan S. F.; Best, Shannon E.; Montes de Oca, Marcela; Amante, Fiona H.; Thomas, Bryce S.; Beattie, Lynette; Souza-Fonseca-Guimaraes, Fernando; Smyth, Mark J.; Hertzog, Paul J.; Hill, Geoffrey R.; Engwerda, Christian R.

    2016-01-01

    Parasite-specific antibodies protect against blood-stage Plasmodium infection. However, in malaria-endemic regions, it takes many months for naturally-exposed individuals to develop robust humoral immunity. Explanations for this have focused on antigenic variation by Plasmodium, but have considered less whether host production of parasite-specific antibody is sub-optimal. In particular, it is unclear whether host immune factors might limit antibody responses. Here, we explored the effect of Type I Interferon signalling via IFNAR1 on CD4+ T-cell and B-cell responses in two non-lethal murine models of malaria, P. chabaudi chabaudi AS (PcAS) and P. yoelii 17XNL (Py17XNL) infection. Firstly, we demonstrated that CD4+ T-cells and ICOS-signalling were crucial for generating germinal centre (GC) B-cells, plasmablasts and parasite-specific antibodies, and likewise that T follicular helper (Tfh) cell responses relied on B cells. Next, we found that IFNAR1-signalling impeded the resolution of non-lethal blood-stage infection, which was associated with impaired production of parasite-specific IgM and several IgG sub-classes. Consistent with this, GC B-cell formation, Ig-class switching, plasmablast and Tfh differentiation were all impaired by IFNAR1-signalling. IFNAR1-signalling proceeded via conventional dendritic cells, and acted early by limiting activation, proliferation and ICOS expression by CD4+ T-cells, by restricting the localization of activated CD4+ T-cells adjacent to and within B-cell areas of the spleen, and by simultaneously suppressing Th1 and Tfh responses. Finally, IFNAR1-deficiency accelerated humoral immune responses and parasite control by boosting ICOS-signalling. Thus, we provide evidence of a host innate cytokine response that impedes the onset of humoral immunity during experimental malaria. PMID:27812214

  1. Subcompartmentalisation of proteins in the rhoptries correlates with ordered events of erythrocyte invasion by the blood stage malaria parasite.

    Directory of Open Access Journals (Sweden)

    Elizabeth S Zuccala

    Full Text Available Host cell infection by apicomplexan parasites plays an essential role in lifecycle progression for these obligate intracellular pathogens. For most species, including the etiological agents of malaria and toxoplasmosis, infection requires active host-cell invasion dependent on formation of a tight junction - the organising interface between parasite and host cell during entry. Formation of this structure is not, however, shared across all Apicomplexa or indeed all parasite lifecycle stages. Here, using an in silico integrative genomic search and endogenous gene-tagging strategy, we sought to characterise proteins that function specifically during junction-dependent invasion, a class of proteins we term invasins to distinguish them from adhesins that function in species specific host-cell recognition. High-definition imaging of tagged Plasmodium falciparum invasins localised proteins to multiple cellular compartments of the blood stage merozoite. This includes several that localise to distinct subcompartments within the rhoptries. While originating from the same organelle, however, each has very different dynamics during invasion. Apical Sushi Protein and Rhoptry Neck protein 2 release early, following the junction, whilst a novel rhoptry protein PFF0645c releases only after invasion is complete. This supports the idea that organisation of proteins within a secretory organelle determines the order and destination of protein secretion and provides a localisation-based classification strategy for predicting invasin function during apicomplexan parasite invasion.

  2. Discovery of GAMA, a Plasmodium falciparum merozoite micronemal protein, as a novel blood-stage vaccine candidate antigen.

    Science.gov (United States)

    Arumugam, Thangavelu U; Takeo, Satoru; Yamasaki, Tsutomu; Thonkukiatkul, Amporn; Miura, Kazutoyo; Otsuki, Hitoshi; Zhou, Hong; Long, Carole A; Sattabongkot, Jetsumon; Thompson, Jennifer; Wilson, Danny W; Beeson, James G; Healer, Julie; Crabb, Brendan S; Cowman, Alan F; Torii, Motomi; Tsuboi, Takafumi

    2011-11-01

    One of the solutions for reducing the global mortality and morbidity due to malaria is multivalent vaccines comprising antigens of several life cycle stages of the malarial parasite. Hence, there is a need for supplementing the current set of malaria vaccine candidate antigens. Here, we aimed to characterize glycosylphosphatidylinositol (GPI)-anchored micronemal antigen (GAMA) encoded by the PF08_0008 gene in Plasmodium falciparum. Antibodies were raised against recombinant GAMA synthesized by using a wheat germ cell-free system. Immunoelectron microscopy demonstrated for the first time that GAMA is a microneme protein of the merozoite. Erythrocyte binding assays revealed that GAMA possesses an erythrocyte binding epitope in the C-terminal region and it binds a nonsialylated protein receptor on human erythrocytes. Growth inhibition assays revealed that anti-GAMA antibodies can inhibit P. falciparum invasion in a dose-dependent manner and GAMA plays a role in the sialic acid (SA)-independent invasion pathway. Anti-GAMA antibodies in combination with anti-erythrocyte binding antigen 175 exhibited a significantly higher level of invasion inhibition, supporting the rationale that targeting of both SA-dependent and SA-independent ligands/pathways is better than targeting either of them alone. Human sera collected from areas of malaria endemicity in Mali and Thailand recognized GAMA. Since GAMA in P. falciparum is refractory to gene knockout attempts, it is essential to parasite invasion. Overall, our study indicates that GAMA is a novel blood-stage vaccine candidate antigen.

  3. Insertion polymorphisms of mobile genetic elements in sexual and asexual populations of Daphnia pulex.

    Science.gov (United States)

    Jiang, Xiaoqian; Tang, Haixu; Ye, Zhiqiang; Lynch, Michael

    2017-01-04

    Transposable elements (TEs) constitute a substantial portion of many eukaryotic genomes, and can in principle contribute to evolutionary innovation as well as genomic deterioration. Daphnia pulex serves as a useful model for studying TE dynamics as a potential cause and/or consequence of asexuality. We analyzed insertion polymorphisms of TEs in 20 sexual and 20 asexual isolates of D. pulex across North American from their available whole-genome sequencing data. Our results show that the total fraction of the derived sequences of TEs is not substantially different between asexual and sexual D. pulex isolates. However, in general, sexual clones contain fewer fixed TE insertions but more total insertion polymorphisms than asexual clones, supporting the hypothesis that sexual reproduction facilitates the spread and elimination of TEs. We identified 9 asexual-specific fixed TE insertions, 8 LTR retrotransposons and 1 DNA transposon. By comparison, no sexual-specific fixed TE insertions were observed in our analysis. Furthermore, except 1 TE insertion located on a contig from chromosome 7, the other 8 asexual-specific insertion sites are located on contigs from chromosome 9 that is known to be associated with obligate asexuality in D. pulex. We found that all 9 asexual-specific fixed TE insertions can also be detected in some D. pulicaria isolates, indicating that a substantial number of TE insertions in asexual D. pulex have been directly inherited from D. pulicaria during the origin of obligate asexuals.

  4. Physiological and subjective sexual arousal in self-identified asexual women.

    Science.gov (United States)

    Brotto, Lori A; Yule, Morag A

    2011-08-01

    Asexuality can be defined as a lifelong lack of sexual attraction. Empirical research on asexuality reveals significantly lower self-reported sexual desire and arousal and lower rates of sexual activity; however, the speculation that there may also be an impaired psychophysiological sexual arousal response has never been tested. The aim of this study was to compare genital (vaginal pulse amplitude; VPA) and subjective sexual arousal in asexual and non-asexual women. Thirty-eight women between the ages of 19 and 55 years (10 heterosexual, 10 bisexual, 11 homosexual, and 7 asexual) viewed neutral and erotic audiovisual stimuli while VPA and self-reported sexual arousal and affect were measured. There were no significant group differences in the increased VPA and self-reported sexual arousal response to the erotic film between the groups. Asexuals showed significantly less positive affect, sensuality-sexual attraction, and self-reported autonomic arousal to the erotic film compared to the other groups; however, there were no group differences in negative affect or anxiety. Genital-subjective sexual arousal concordance was significantly positive for the asexual women and non-significant for the other three groups, suggesting higher levels of interoceptive awareness among asexuals. Taken together, the findings suggest normal subjective and physiological sexual arousal capacity in asexual women and challenge the view that asexuality should be characterized as a sexual dysfunction.

  5. Do asexual polyploid lineages lead short evolutionary lives? A case study from the fern genus Astrolepis.

    Science.gov (United States)

    Beck, James B; Windham, Michael D; Pryer, Kathleen M

    2011-11-01

    A life-history transition to asexuality is typically viewed as leading to a heightened extinction risk, and a number of studies have evaluated this claim by examining the relative ages of asexual versus closely related sexual lineages. Surprisingly, a rigorous assessment of the age of an asexual plant lineage has never been published, although asexuality is extraordinarily common among plants. Here, we estimate the ages of sexual diploids and asexual polyploids in the fern genus Astrolepis using a well-supported plastid phylogeny and a relaxed-clock dating approach. The 50 asexual polyploid samples we included were conservatively estimated to comprise 19 distinct lineages, including a variety of auto- and allopolyploid genomic combinations. All were either the same age or younger than the crown group comprising their maternal sexual-diploid parents based simply on their phylogenetic position. Node ages estimated with the relaxed-clock approach indicated that the average maximum age of asexual lineages was 0.4 My, and individual lineages were on average 7 to 47 times younger than the crown- and total-ages of their sexual parents. Although the confounding association between asexuality and polyploidy precludes definite conclusions regarding the effect of asexuality, our results suggest that asexuality limits evolutionary potential in Astrolepis.

  6. Insertion Polymorphisms of Mobile Genetic Elements in Sexual and Asexual Populations of Daphnia pulex

    Science.gov (United States)

    Ye, Zhiqiang; Lynch, Michael

    2017-01-01

    Transposable elements (TEs) constitute a substantial portion of many eukaryotic genomes, and can in principle contribute to evolutionary innovation as well as genomic deterioration. Daphnia pulex serves as a useful model for studying TE dynamics as a potential cause and/or consequence of asexuality. We analyzed insertion polymorphisms of TEs in 20 sexual and 20 asexual isolates of D. pulex across North American from their available whole-genome sequencing data. Our results show that the total fraction of the derived sequences of TEs is not substantially different between asexual and sexual D. pulex isolates. However, in general, sexual clones contain fewer fixed TE insertions but more total insertion polymorphisms than asexual clones, supporting the hypothesis that sexual reproduction facilitates the spread and elimination of TEs. We identified nine asexual-specific fixed TE insertions, eight long terminal repeat retrotransposons, and one DNA transposon. By comparison, no sexual-specific fixed TE insertions were observed in our analysis. Furthermore, except one TE insertion located on a contig from chromosome 7, the other eight asexual-specific insertion sites are located on contigs from chromosome 9 that is known to be associated with obligate asexuality in D. pulex. We found that all nine asexual-specific fixed TE insertions can also be detected in some Daphnia pulicaria isolates, indicating that a substantial number of TE insertions in asexual D. pulex have been directly inherited from D. pulicaria during the origin of obligate asexuals. PMID:28057730

  7. Differential miRNA Expression in the Liver of Balb/c Mice Protected by Vaccination during Crisis of Plasmodium chabaudi Blood-Stage Malaria

    Science.gov (United States)

    Dkhil, Mohamed A.; Al-Quraishy, Saleh A.; Abdel-Baki, Abdel-Azeem S.; Delic, Denis; Wunderlich, Frank

    2017-01-01

    MicroRNAs are increasingly recognized as epigenetic regulators for outcome of diverse infectious diseases and vaccination efficacy, but little information referring to this exists for malaria. This study investigates possible effects of both protective vaccination and P. chabaudi malaria on the miRNome of the liver as an effector against blood-stage malaria using miRNA microarrays and quantitative PCR. Plasmodium chabaudi blood-stage malaria takes a lethal outcome in female Balb/c mice, but a self-healing course after immunization with a non-infectious blood-stage vaccine. The liver robustly expresses 71 miRNA species at varying levels, among which 65 miRNA species respond to malaria evidenced as steadily increasing or decreasing expressions reaching highest or lowest levels toward the end of the crisis phase on day 11 p.i. in lethal malaria. Protective vaccination does not affect constitutive miRNA expression, but leads to significant (p malaria.

  8. Sexual Fantasy and Masturbation Among Asexual Individuals: An In-Depth Exploration.

    Science.gov (United States)

    Yule, Morag A; Brotto, Lori A; Gorzalka, Boris B

    2017-01-01

    Human asexuality is generally defined as a lack of sexual attraction. We used online questionnaires to investigate reasons for masturbation, and explored and compared the contents of sexual fantasies of asexual individuals (identified using the Asexual Identification Scale) with those of sexual individuals. A total of 351 asexual participants (292 women, 59 men) and 388 sexual participants (221 women, 167 men) participated. Asexual women were significantly less likely to masturbate than sexual women, sexual men, and asexual men. Asexual women were less likely to report masturbating for sexual pleasure or fun than their sexual counterparts, and asexual men were less likely to report masturbating for sexual pleasure than sexual men. Both asexual women and men were significantly more likely than sexual women and men to report that they had never had a sexual fantasy. Of those who have had a sexual fantasy, asexual women and men were significantly more likely to endorse the response "my fantasies do not involve other people" compared to sexual participants, and consistently scored each sexual fantasy on a questionnaire as being less sexually exciting than did sexual participants. When using an open-ended format, asexual participants were more likely to report having fantasies about sexual activities that did not involve themselves, and were less likely to fantasize about topics such as group sex, public sex, and having an affair. Interestingly, there was a large amount of overlap between sexual fantasies of asexual and sexual participants. Notably, both asexual and sexual participants (both men and women) were equally likely to fantasize about topics such as fetishes and BDSM.

  9. Gonad establishment during asexual reproduction in the annelid Pristina leidyi.

    Science.gov (United States)

    Özpolat, B Duygu; Bely, Alexandra E

    2015-09-01

    Animals that can reproduce by both asexual agametic reproduction and sexual reproduction must transmit or re-establish their germ line post-embryonically. Although such a dual reproductive mode has evolved repeatedly among animals, how asexually produced individuals establish their germ line remains poorly understood in most groups. We investigated germ line development in the annelid Pristina leidyi, a species that typically reproduces asexually by paratomic fission, intercalating a new tail and head in the middle of the body followed by splitting. We found that in fissioning individuals, gonads occur in anterior segments in the anterior-most individual as well as in new heads forming within fission zones. Homologs of the germ line/multipotency genes piwi, vasa, and nanos are expressed in the gonads, as well as in proliferative tissues including the posterior growth zone, fission zone, and regeneration blastema. In fissioning animals, certain cells on the ventral nerve cord express a homolog of piwi, are abundant near fission zones, and sometimes make contact with gonads. Such cells are typically undetectable near the blastema and posterior growth zone. Time-lapse imaging provides direct evidence that cells on the ventral nerve cord migrate preferentially towards fission zones. Our findings indicate that gonads form routinely in fissioning individuals, that a population of piwi-positive cells on the ventral nerve cord is associated with fission and gonads, and that cells resembling these piwi-positive cells migrate along the ventral nerve cord. We suggest that the piwi-positive ventral cells are germ cells that transmit the germ line across asexually produced individuals via migration along the ventral nerve cord.

  10. Coevolution of robustness, epistasis, and recombination favors asexual reproduction

    OpenAIRE

    MacCarthy, Thomas; Bergman, Aviv

    2007-01-01

    The prevalence of sexual reproduction remains one of the most perplexing phenomena in evolutionary biology. The deterministic mutation hypothesis postulates that sexual reproduction will be advantageous under synergistic epistasis, a condition in which mutations cause a greater reduction in fitness when combined than would be expected from their individual effects. The inverse condition, antagonistic epistasis, correspondingly is predicted to favor asexual reproduction. To assess this hypothe...

  11. The Genetic Control of Apomixis: Asexual Seed Formation

    OpenAIRE

    Hand, Melanie L; Koltunow, Anna M. G.

    2014-01-01

    Apomixis (asexual seed formation) is the result of a plant gaining the ability to bypass the most fundamental aspects of sexual reproduction: meiosis and fertilization. Without the need for male fertilization, the resulting seed germinates a plant that develops as a maternal clone. This dramatic shift in reproductive process has been documented in many flowering plant species, although no major seed crops have been shown to be capable of apomixis. The ability to generate maternal clones and t...

  12. Morphogenesis during asexual reproduction in Pygospio elegans Claparede (Annelida, Polychaeta).

    Science.gov (United States)

    Gibson, G D; Harvey, J M

    2000-08-01

    The spionid Pygospio elegans reproduces both asexually and sexually. Using scanning electron and bright field microscopy, we examined morphogenesis following asexual reproduction to determine how "lost" body regions were regenerated after a worm spontaneously divided. Asexual reproduction occurred through transverse fission and divided the parent worm into 2 to 6 fragments (architomy). All fragments retained their original anterior-posterior polarity. Regeneration in all fragments followed a specific series of events: wound healing (day 1); extension of the blastema to generate lost body regions-specifically, the head and thorax for posterior fragments and the tail and pygidium for anterior fragments (days 2-3); segmentation (days 3-6); and differentiation of segment- or region-specific structures (days 4-8). This pattern occurred regardless of where the original division took place. Subsequent growth occurred through addition of terminal setigers anterior to the pygidium followed by differentiation of tail setigers into abdominal setigers, leaving the tail region about 6 to 10 setigers in size. Division rates were compared in worms from three populations in Nova Scotia, Canada. Worms from two populations (Conrad's Beach, Starr's Point) divided more frequently (about 1.2 and 1.3 weeks between divisions, respectively) than worms from Bon Portage Island (3.5 weeks between divisions). Fragments containing the original head (original mouth intact, generally much larger fragment) had a higher survivorship than fragments containing the original tail.

  13. Genetic variation in organisms with sexual and asexual reproduction.

    Science.gov (United States)

    Bengtsson, B O

    2003-03-01

    The genetic variation in a partially asexual organism is investigated by two models suited for different time scales. Only selectively neutral variation is considered. Model 1 shows, by the use of a coalescence argument, that three sexually derived individuals per generation are sufficient to give a population the same pattern of allelic variation as found in fully sexually reproducing organisms. With less than one sexual event every third generation, the characteristic pattern expected for asexual organisms appear, with strong allelic divergence between the gene copies in individuals. At intermediary levels of sexuality, a complex situation reigns. The pair-wise allelic divergence under partial sexuality exceeds, however, always the corresponding value under full sexuality. These results apply to large populations with stable reproductive systems. In a more general framework, Model 2 shows that a small number of sexual individuals per generation is sufficient to make an apparently asexual population highly genotypically variable. The time scale in terms of generations needed to produce this effect is given by the population size and the inverse of the rate of sexuality.

  14. Blood levels of vitamin D and early stage breast cancer prognosis: a systematic review and meta-analysis.

    Science.gov (United States)

    Rose, April A N; Elser, Christine; Ennis, Marguerite; Goodwin, Pamela J

    2013-10-01

    Vitamin D regulates expression of genes important in development and progression of breast cancer. The association of vitamin D with breast cancer outcomes among breast cancer patients is controversial. We conducted a systematic review and meta-analysis of this association in early stage breast cancer outcome. We searched MEDLINE (1982-May 1, 2013), the American Society of Clinical Oncology (2009-2012), and the San Antonio Breast Cancer Symposium (2010-2012) for abstracts, using the following keywords: "breast cancer" and "prognosis" or "survival", and "vitamin D" or" calcitriol" to identify studies reporting the associations of blood vitamin D levels (drawn close to diagnosis) with breast cancer outcomes. Meta-analyses were performed using an inverse-variance weighted fixed-effects model with Stata Version 12. Eight studies including 5,691 patients were identified. Vitamin D deficiency was variably categorized across studies; a median of 36.8 % of patients were classified as deficient. Low vitamin D levels were associated with a pooled hazard ratio of 2.13 (95 % CI 1.64-2.78) and 1.76 (95 % CIs 1.35-2.30) for recurrence (six studies) and death (four studies), respectively, with no evidence of significant heterogeneity across studies. There was potential evidence of a publication bias in studies examining associations with death (but not in those examining associations with recurrence). These findings support an association of low levels of vitamin D with increased risk of recurrence and death in early stage breast cancer patients. Given the observational nature of the included studies, it cannot be concluded that this association is causal. Further research is warranted to investigate the potential beneficial effects of vitamin D in breast cancer.

  15. Coexistence of sexual individuals and genetically isolated asexual counterparts in a thrips.

    Science.gov (United States)

    Kobayashi, Kazuya; Yoshimura, Jin; Hasegawa, Eisuke

    2013-11-21

    Sex is a paradoxical phenomenon because it is less efficient compared with asexual reproduction. To resolve this paradox we need a direct comparison between sexual and asexual forms. In many organisms, however, sexual and asexual forms do not occur in the same habitat, or at the same time. In a few cases where sexual and asexual forms are found in a single population, some (though rare) genetic exchange is usually detected between the two forms. When genetic exchange occurs a direct comparison is impossible. Here we investigate a thrips exhibiting both sexual and asexual forms (lineages) that are morphologically indistinguishable. We examine if the two forms are genetically isolated. Phylogeny based on nuclear genes confirms that the sexual and asexual lineages are genetically differentiated. Thus we demonstrate that the current system has certain advantages over existing and previously used model systems in the evolution of sexual reproduction.

  16. A NEW METHOD OF SINGLE-STAGE ISLAND PLASTY BY TWO BONE AUTOGRAFTS WITH BLOOD SUPPLY IN PATIENTS WITH PSEUDOARTHROSIS OF BOTH FOREARM BONES

    Directory of Open Access Journals (Sweden)

    R. M. Tikhilov

    2010-01-01

    Full Text Available The applied topographic-anatomic studies prepared in 14 fixed and 16 unfixed preparations of upper extremity allowed to precise the details of radius blood supply with reference to possibilities of formation of bone autografts with blood supply. Due to this fact the novel method of single-stage bone plasty for pseudoarthrosis of both forearm bones was developed and successfully approved in clinic. This method proposes the formation of two periosteal-cortical grafts with blood supply and small muscle cuff in distal and middle one-thirds of radius simultaneously.

  17. Identification of MMV malaria box inhibitors of plasmodium falciparum early-stage gametocytes using a luciferase-based high-throughput assay.

    Science.gov (United States)

    Lucantoni, Leonardo; Duffy, Sandra; Adjalley, Sophie H; Fidock, David A; Avery, Vicky M

    2013-12-01

    The design of new antimalarial combinations to treat Plasmodium falciparum infections requires drugs that, in addition to resolving disease symptoms caused by asexual blood stage parasites, can also interrupt transmission to the mosquito vector. Gametocytes, which are essential for transmission, develop as sexual blood stage parasites in the human host over 8 to 12 days and are the most accessible developmental stage for transmission-blocking drugs. Considerable effort is currently being devoted to identifying compounds active against mature gametocytes. However, investigations on the drug sensitivity of developing gametocytes, as well as screening methods for identifying inhibitors of early gametocytogenesis, remain scarce. We have developed a luciferase-based high-throughput screening (HTS) assay using tightly synchronous stage I to III gametocytes from a recombinant P. falciparum line expressing green fluorescent protein (GFP)-luciferase. The assay has been used to evaluate the early-stage gametocytocidal activity of the MMV Malaria Box, a collection of 400 compounds with known antimalarial (asexual blood stage) activity. Screening this collection against early-stage (I to III) gametocytes yielded 64 gametocytocidal compounds with 50% inhibitory concentrations (IC50s) below 2.5 μM. This assay is reproducible and suitable for the screening of large compound libraries, with an average percent coefficient of variance (%CV) of ≤5%, an average signal-to-noise ratio (S:N) of >30, and a Z' of ∼0.8. Our findings highlight the need for screening efforts directed specifically against early gametocytogenesis and indicate the importance of experimental verification of early-stage gametocytocidal activity in the development of new antimalarial candidates for combination therapy.

  18. Single-locus recessive inheritance of asexual reproduction in a parasitoid wasp.

    Science.gov (United States)

    Sandrock, Christoph; Vorburger, Christoph

    2011-03-08

    The evolutionary maintenance of sex is one of the big unresolved puzzles in biology. All else being equal, all-female asexual populations should enjoy a two-fold reproductive advantage over sexual relatives consisting of male and female individuals. However, the "all else being equal" assumption rarely holds in real organisms because asexuality tends to be confounded with altered genomic constitutions such as hybridization and polyploidization or to be associated with parthenogenesis-inducing microbes. This limits the ability to draw general conclusions from any particular system. Here we describe a new system that permits unbiased comparisons of sexual and asexual reproduction: the parasitic wasp Lysiphlebus fabarum. Crossing experiments demonstrated that asexual reproduction has a simple genetic basis in this species and is consistently inherited as a single-locus recessive trait. We further show that the asexuality-inducing allele exhibits complete linkage to a specific allele at a microsatellite marker: all asexual lines in the field were homozygous for this allele, and the allele cosegregated perfectly with asexual reproduction in our experimental crossings. This novel system of contagious asexuality allows the production of closely related individuals with different reproductive modes, as well as the monitoring of the asexuality-inducing allele in natural and experimental populations.

  19. Existence of two sexual races in the planarian species switching between asexual and sexual reproduction.

    Science.gov (United States)

    Kobayashi, Kazuya; Maezawa, Takanobu; Nakagawa, Haruka; Hoshi, Motonori

    2012-04-01

    In certain planarian species that are able to switch between asexual and sexual reproduction, determining whether a sexual has the ability to switch to the asexual state is problematic, which renders the definition of sexuals controversial. We experimentally show the existence of two sexual races, acquired and innate, in the planarian Dugesia ryukyuensis. Acquired sexuals used in this study were experimentally switched from asexuals. Inbreeding of acquired sexuals produced both innate sexuals and asexuals, but inbreeding of innate sexuals produced innate sexuals only and no asexuals. Acquired sexuals, but not innate sexuals, were forced to become asexuals by ablation and regeneration (asexual induction). This suggests that acquired sexuals somehow retain asexual potential, while innate sexuals do not. We also found that acquired sexuals have the potential to develop hyperplastic and supernumerary ovaries, while innate sexuals do not. In this regard, acquired sexuals were more prolific than innate sexuals. The differences between acquired and innate sexuals will provide a structure for examining the mechanism underlying asexual and sexual reproduction in planarians.

  20. Dynamics of asexual reproduction in planarians

    Science.gov (United States)

    Schoetz, Eva-Maria; Lincoln, Bryan; Quinodoz, Sofia

    2011-03-01

    Planaria research is experiencing a resurgence due to the development of molecular tools, the Planarian genome project and database resources. Despite the resulting progress in planarian biology research, an extensive study of their physical properties remains to be undertaken. We developed a method to collect a large amount of data on the dynamics of clonal reproduction in the freshwater planarian S.mediterranea. The capability of planarians to regenerate an entire organism from a minuscule body part is based on a homogeneously distributed stem cell population that comprises 25-30% of all cells. Due to this stem cell contingent, planarians can reproduce spontaneously by dividing into a larger head and a smaller tail piece, which then will rebuild the missing body parts, including a central nervous system, within about a week. Time-lapse imaging allows us to characterize the fission process in detail, revealing the stages of the process as well as capturing the nature of the rupture itself. A traction force measurement setup is being developed to allow us to quantify the forces planarians exert on the substrate during reproduction, a macroscopic analog to the Traction Force Microscopy setups used to determine local cellular forces. We are particularly interested in the molecular processes during division and the interplay between tissue mechanics and cell signaling.

  1. Cytokine responses of CD4+ T cells during a Plasmodium chabaudi chabaudi (ER blood-stage infection in mice initiated by the natural route of infection

    Directory of Open Access Journals (Sweden)

    Butcher Geoffrey

    2007-06-01

    Full Text Available Abstract Background Investigation of host responses to blood stages of Plasmodium spp, and the immunopathology associated with this phase of the life cycle are often performed on mice infected directly with infected red blood cells. Thus, the effects of mosquito bites and the pre-erythrocytic stages of the parasite, which would be present in natural infection, are ignored In this paper, Plasmodium chabaudi chabaudi infections of mice injected directly with infected red blood cells were compared with those of mice infected by the bites of infected mosquitoes, in order to determine whether the courses of primary infection and splenic CD4 T cell responses are similar. Methods C57Bl/6 mice were injected with red blood cells infected with P. chabaudi (ER or infected via the bite of Anopheles stephensi mosquitoes. Parasitaemia were monitored by Giemsa-stained thin blood films. Total spleen cells, CD4+ T cells, and cytokine production (IFN-γ, IL-2, IL-4, IL-10 were analysed by flow cytometry. In some experiments, mice were subjected to bites of uninfected mosquitoes prior to infectious bites in order to determine whether mosquito bites per se could affect a subsequent P. chabaudi infection. Results P. chabaudi (ER infections initiated by mosquito bite were characterized by lower parasitaemia of shorter duration than those observed after direct blood challenge. However, splenomegaly was comparable suggesting that parasitaemia alone does not account for the increase in spleen size. Total numbers of CD4 T cells and those producing IFN-γ, IL-10 and IL-2 were reduced in comparison to direct blood challenge. By contrast, the reduction in IL-4 producing cells was less marked suggesting that there is a proportionally lower Th1-like response in mice infected via infectious mosquitoes. Strikingly, pre-exposure to bites of uninfected mosquitoes reduced the magnitude and duration of the subsequent mosquito-transmitted infection still further, but enhanced the

  2. Evaluation of elevated ploidy and asexual reproduction as alternative explanations for geographic parthenogenesis in Eucypris virens ostracods.

    Science.gov (United States)

    Adolfsson, Sofia; Michalakis, Yannis; Paczesniak, Dorota; Bode, Saskia N S; Butlin, Roger K; Lamatsch, Dunja K; Martins, Maria J F; Schmit, Olivier; Vandekerkhove, Jochen; Jokela, Jukka

    2010-04-01

    Transitions from sexual to asexual reproduction are often coupled with elevations in ploidy. As a consequence, the importance of ploidy per se for the maintenance and spread of asexual populations is unclear. To examine the effects of ploidy and asexual reproduction as independent determinants of the success of asexual lineages, we sampled diploid sexual, diploid asexual, and triploid asexual Eucypris virens ostracods across a European wide range. Applying nuclear and mitochondrial markers, we found that E. virens consists of genetically highly differentiated diploid sexual populations, to the extent that these sexual clades could be considered as cryptic species. All sexual populations were found in southern Europe and North Africa and we found that both diploid asexual and triploid asexual lineages have originated multiple times from several sexual lineages. Therefore, the asexual lineages show a wide variety of genetic backgrounds and very strong population genetic structure across the wide geographic range. Finally, we found that triploid, but not diploid, asexual clones dominate habitats in northern Europe. The limited distribution of diploid asexual lineages, despite their shared ancestry with triploid asexual lineages, strongly suggests that the wider geographic distribution of triploids is due to elevated ploidy rather than to asexuality.

  3. Efficacy of OZ439 (artefenomel) against early Plasmodium falciparum blood-stage malaria infection in healthy volunteers

    Science.gov (United States)

    McCarthy, James S.; Baker, Mark; O'Rourke, Peter; Marquart, Louise; Griffin, Paul; Hooft van Huijsduijnen, Rob; Möhrle, Jörg J.

    2016-01-01

    Objectives OZ439, or artefenomel, is an investigational synthetic ozonide antimalarial with similar potency, but a significantly improved pharmacokinetic profile, compared with artemisinins. We wished to measure key pharmacokinetic and pharmacodynamic parameters and the pharmacokinetic/pharmacodynamic relationship of artefenomel in humans to guide the drug's further development as combination therapy in patients. Patients and methods We tested artefenomel in the human induced blood-stage malaria (IBSM) model. Plasmodium infection was monitored by quantitative PCR (qPCR) and upon reaching 1000 parasites/mL single doses of 100, 200 and 500 mg of artefenomel were administered orally with evaluation of drug exposure and parasitaemia until rescue treatment after 16 days or earlier, if required. Results A single 100 mg dose had only a transient effect, while the 200 mg dose resulted in a significant reduction in parasitaemia before early recrudescence. At the highest (500 mg) dose, initial clearance of parasites below the limit of detection of qPCR was observed, with a 48 h parasite reduction ratio (PRR48) >10 000 and a parasite clearance half-life of 3.6 h (95% CI 3.4–3.8 h). However, at this dose, recrudescence was seen in four of eight subjects 6–10 days after treatment. Pharmacokinetic/pharmacodynamic modelling predicted an MIC of 4.1 ng/mL. Conclusions These results confirm the antimalarial potential of artefenomel for use in a single-exposure combination therapy. The observations from this study support and will assist further clinical development of artefenomel. PMID:27272721

  4. Simulated emergence of cyclic sexual-asexual reproduction

    Science.gov (United States)

    Sá Martins, J. S.; Racco, A.

    2001-08-01

    Motivated by the cyclic pattern of reproductive regimes observed in some species of green flies (“ aphids”), we simulate the evolution of a population enduring harsh seasonal conditions for survival. The reproductive regime of each female is also seasonal in principle and genetically acquired, and can mutate for each newborn with some small probability. The results show a sharp transition at a critical value of the survival probability in the winter, between a reproductive regime in the fall that is predominantly sexual, for low values of this probability, or asexual, for high values.

  5. [Regulation of asexual reproduction in the planarian Dugesia tigrina].

    Science.gov (United States)

    Sheĭman, I M; Sakharova, N Iu; Tiras, Kh P; Shkutin, M F; Isaeva, V V

    2003-01-01

    We studied asexual reproduction of planarians under the natural and artificial photoperiodic conditions. It was shown that light inhibits the fission of planarians, while darkness stimulates it. The diurnal dynamics of the fission of planarians demonstrated a circadian rhythm. This rhythm is stable, which is expressed when the conditions are experimentally changed: constant darkness, unnatural rhythm of light-darkness succession). However, this stability is affected at the time zone change. The planarians are adapted to new conditions and begin to fission at once in correspondence with the new diurnal regime.

  6. Increased SOCS expression in peripheral blood mononuclear cells of end stage renal disease patients is related to inflammation and dialysis modality.

    Science.gov (United States)

    Rastmanesh, M Mehdi; Braam, Branko; Joles, Jaap A; Boer, Peter; Bluyssen, Hans A R

    2009-01-05

    Inflammation is a characteristic of cardiovascular disease and is increased in end-stage renal disease. Suppressors of cytokine signaling (SOCS) inhibit and reflect activation of intracellular inflammatory pathways. We hypothesized that SOCS expression in peripheral blood mononuclear cells of end stage renal disease patients is increased. Whether SOCS expression in peripheral blood mononuclear cells is related to inflammation, dialysis, and dialysis modality was investigated. Monocytes and lymphocytes were isolated from peripheral blood mononuclear cells of patients not on dialysis (n=8), on peritoneal dialysis (n=8), on hemodialysis (n=14) and of healthy control (n=15) subjects. SOCS expression was assessed by real-time quantitative PCR and plasma cytokines by ELISA. In end stage renal disease patients monocyte SOCS1, and lymphocyte SOCS1 and cytokine-inducible SH2 containing protein-1 (CIS-1) gene expression were increased along with increased plasma levels of interleukin (IL)-6, tumor necrosis factor (TNF)alpha ,and C-reactive protein (CRP). Monocyte SOCS1 correlated with IL-6. Lymphocyte CIS-1 was increased in non-dialysis and peritoneal dialysis but not in hemodialysis patients. Lymphocyte CIS-1 in peritoneal dialysis patients correlated with plasma TNFalpha. Despite the relatively low number of patients studied we observed increased expression of SOCS1 in both monocytes and lymphocytes, and of CIS-1 solely in lymphocytes of the patients. SOCS expression was related to increased systemic inflammation, illustrated by a significant correlation between monocyte SOCS1 and plasma IL-6. SOCS expression in peripheral blood mononuclear cells was also affected by hemodialysis, indicated by increased lymphocyte CIS-1 in non-dialysis and peritoneal dialysis but not in hemodialysis patients. We suggest that increased SOCS expression in peripheral blood mononuclear cells of end stage renal disease patients reflects whether and to which extent systemic inflammation

  7. Evolution of asexuality via different mechanisms in grass thrips (Thysanoptra: Aptinothrips)

    NARCIS (Netherlands)

    van der Kooi, Casper J.; Schwander, Tanja

    2014-01-01

    Asexual lineages can derive from sexual ancestors via different mechanisms and at variable rates, which affects the diversity of the asexual population and thereby its ecological success. We investigated the variation and evolution of reproductive systems in Aptinothrips, a genus of grass thrips com

  8. Comparative toxicant sensitivity of sexual and asexual reproduction in the rotifer Brachionus calyciflorus

    Energy Technology Data Exchange (ETDEWEB)

    Snell, T.W. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Biology; Carmona, M.J. [Univ. de Valencia (Spain). Area de Ecologia

    1995-03-01

    Cyclically parthenogenetic zooplankters like rotifers are important tools for assessing toxicity in aquatic environments. Sexual reproduction is an essential component of rotifer life cycles, but current toxicity tests utilize only asexual reproduction. The authors compared the effects of four toxicants on asexual and sexual reproduction of the rotifer Brachionus calyciflorus. Toxicants had a differential effect on sexual and asexual reproduction, with sexual reproduction consistently the most sensitive. Concentrations of 0.2 {mu}g/ml PCP (sodium pentachlorophenate) had no effect on the asexual reproductive rate, but significantly reduced sexual reproduction. Likewise, chlorpyrifos concentrations of 0.3 {mu}g/ml had no significant effect on asexual reproduction, but sexual reproduction was significantly reduced. There was no difference in NOECs, LOECs, and chronic values for asexual and sexual reproduction for cadmium and naphthol tests. However, comparison of toxicant effect levels revealed that sexual reproduction was more strongly reduced at each toxicant concentration. The four toxicants tested inhibited sexual reproduction 2 to 68 times more than asexual reproduction at the lowest observed effect concentrations. Toxicants inhibited sexual reproduction in its initial step: sexual female production. Because sexual reproduction is more sensitive, toxicity tests based exclusively on asexual reproduction may not be protective of rotifer life cycles.

  9. A population of sexual Daphnia pulex resists invasion by asexual clones.

    Science.gov (United States)

    Innes, David J; Ginn, Michael

    2014-08-07

    Asexual reproduction avoids the costs associated with sex, predicting that invading asexual clones can quickly replace sexual populations. Daphnia pulex populations in the Great Lakes area are predominately asexual, but the elimination of sexual populations by invading clones is poorly understood. Asexual clones were detected at low frequency in one rare sexual population in 1995, with some increase in frequency during 2003 and 2004. However, these clones remained at low frequency during further yearly sampling (2005-2013) with no evidence that the resident sexual population was in danger of elimination. There was evidence for hybridization between rare males produced by asexual clones and sexual females with the potential to produce new asexual genotypes and spread the genetic factors for asexuality. In a short-term laboratory competition experiment, the two most common asexual clones did not increase in frequency relative to a genetically diverse sexual population due in part to a greater investment in diapausing eggs that trades-off current population growth for increased contribution to the egg bank. Our results suggest that a successful invasion can be prolonged, requiring a combination of clonal genotypes with high fitness, persistence of clones in the egg bank and negative factors affecting the sexual population such as inbreeding depression resulting from population bottlenecks.

  10. The exact distributions of F(IS under partial asexuality in small finite populations with mutation.

    Directory of Open Access Journals (Sweden)

    Solenn Stoeckel

    Full Text Available Reproductive systems like partial asexuality participate to shape the evolution of genetic diversity within populations, which is often quantified by the inbreeding coefficient F IS. Understanding how those mating systems impact the possible distributions of F IS values in theoretical populations helps to unravel forces shaping the evolution of real populations. We proposed a population genetics model based on genotypic states in a finite population with mutation. For populations with less than 400 individuals, we assessed the impact of the rates of asexuality on the full exact distributions of F IS, the probabilities of positive and negative F IS, the probabilities of fixation and the probabilities to observe changes in the sign of F IS over one generation. After an infinite number of generations, we distinguished three main patterns of effects of the rates of asexuality on genetic diversity that also varied according to the interactions of mutation and genetic drift. Even rare asexual events in mainly sexual populations impacted the balance between negative and positive F IS and the occurrence of extreme values. It also drastically modified the probability to change the sign of F IS value at one locus over one generation. When mutation prevailed over genetic drift, increasing rates of asexuality continuously increased the variance of F IS that reached its highest value in fully asexual populations. In consequence, even ancient asexual populations showed the entire F IS spectrum, including strong positive F IS. The prevalence of heterozygous loci only occurred in full asexual populations when genetic drift dominated.

  11. On the origin of asexual species by means of hybridization and drift

    DEFF Research Database (Denmark)

    Hartfield, Matthew

    2016-01-01

    Several species of asexuals appear to have existed for millions of years. This is despite the prevalent view that natural selection is weakened without gene exchange, which should cause these organisms to rapidly go extinct. In theory, one can identify evolutionary long-lived asexuals from...

  12. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage

    Directory of Open Access Journals (Sweden)

    Agnieszka Morel

    2015-01-01

    Full Text Available Multiple sclerosis (MS is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases were examined to evaluate the biological activity of blood platelets (adhesion, aggregation, especially their response to the most important physiological agonists (thrombin, ADP, and collagen and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2-∙ in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets.

  13. Malaria parasite-synthesized heme is essential in the mosquito and liver stages and complements host heme in the blood stages of infection.

    Directory of Open Access Journals (Sweden)

    Viswanathan Arun Nagaraj

    Full Text Available Heme metabolism is central to malaria parasite biology. The parasite acquires heme from host hemoglobin in the intraerythrocytic stages and stores it as hemozoin to prevent free heme toxicity. The parasite can also synthesize heme de novo, and all the enzymes in the pathway are characterized. To study the role of the dual heme sources in malaria parasite growth and development, we knocked out the first enzyme, δ-aminolevulinate synthase (ALAS, and the last enzyme, ferrochelatase (FC, in the heme-biosynthetic pathway of Plasmodium berghei (Pb. The wild-type and knockout (KO parasites had similar intraerythrocytic growth patterns in mice. We carried out in vitro radiolabeling of heme in Pb-infected mouse reticulocytes and Plasmodium falciparum-infected human RBCs using [4-(14C] aminolevulinic acid (ALA. We found that the parasites incorporated both host hemoglobin-heme and parasite-synthesized heme into hemozoin and mitochondrial cytochromes. The similar fates of the two heme sources suggest that they may serve as backup mechanisms to provide heme in the intraerythrocytic stages. Nevertheless, the de novo pathway is absolutely essential for parasite development in the mosquito and liver stages. PbKO parasites formed drastically reduced oocysts and did not form sporozoites in the salivary glands. Oocyst production in PbALASKO parasites recovered when mosquitoes received an ALA supplement. PbALASKO sporozoites could infect mice only when the mice received an ALA supplement. Our results indicate the potential for new therapeutic interventions targeting the heme-biosynthetic pathway in the parasite during the mosquito and liver stages.

  14. Skeletogenesis and asexual reproduction in the earliest biomineralizing animal Cloudina

    Science.gov (United States)

    Hua, Hong; Chen, Zhe; Yuan, Xunlai; Zhang, Luyi; Xiao, Shuhai

    2005-04-01

    The tubular fossil Cloudina is emerging as an important Ediacaran index fossil. However, its morphology, skeletogenesis, reproduction, and phylogenetic affinity have not been fully resolved. New material from the Dengying Formation of south China confirms that Cloudina tubes consist of eccentrically and sometimes deeply nested funnels and that the tubes lack transverse cross-walls, inconsistent with the traditional cone-in-cone morphological reconstruction. Tube walls are composed of micrometer-sized, more or less equant crystals. A number of Cloudina tubes branch dichotomously, in which daughter funnels split within parent ones. The Cloudina animal is interpreted to have been able to initiate biomineralization of new funnels within old ones. Its skeleton was probably secreted as calcite crystals suspended in organic matrix; the crystals do not appear to have nucleated and grown on a sheeted substrate. It was clearly capable of asexual reproduction, through budding within parent funnels rather than at the apertural end. The morphology, skeletogenesis, and asexual reproduction of Cloudina are broadly similar to modern serpulid annelids, indicating possible phylogenetic relationships or morphological convergence.

  15. Identification of Phytophthora sojae genes involved in asexual sporogenesis

    Indian Academy of Sciences (India)

    Ziying Wang; Xhaoxia Wang; Jie Shen; Guangyue Wang; Xiaoxi Zhu; Hongxia Lu

    2009-08-01

    To explore the molecular mechanisms involved in asexual spore development in Phytophthora sojae, the zoospores of strain PS26 were treated with ultraviolet (UV) irradiation. After selection, a mutant progeny, termed PS26-U03, was obtained and demonstrated to exhibit no oospore production. A suppression subtractive hybridization (SSH) approach was developed to investigate differences in gene expression between PS26 and PS26-U03 during asexual sporogenesis. Of the 126 sequences chosen for examination, 39 putative unigenes were identified that exhibit high expression in PS26. These sequences are predicted to encode proteins involved in metabolism, cell cycle, protein biosynthesis, cell signalling, cell defence, and transcription regulation. Seven clones were selected for temporal expression analysis using RT-PCR based on the results of the dot-blot screens. Three of the selected genes, developmental protein DG1037 (UB88), glycoside hydrolase (UB149) and a hypothetical protein (UB145), were expressed only in PS26, whereas the transcripts of phosphatidylinositol-4-phosphate 5-kinase (UB36), FAD-dependent pyridine nucleotide-disulphide oxidoreductase (UB226) and sugar transporter (UB256) were expressed at very low levels in PS26-U03 but at high levels in PS26.

  16. Genetic diversity and fitness in small populations of partially asexual, self-incompatible plants.

    Science.gov (United States)

    Navascués, M; Stoeckel, S; Mariette, S

    2010-05-01

    How self-incompatibility systems are maintained in plant populations is still a debated issue. Theoretical models predict that self-incompatibility systems break down according to the intensity of inbreeding depression and number of S-alleles. Other studies have explored the function of asexual reproduction in the maintenance of self-incompatibility. However, the population genetics of partially asexual, self-incompatible populations are poorly understood and previous studies have failed to consider all possible effects of asexual reproduction or could only speculate on those effects. In this study, we investigated how partial asexuality may affect genetic diversity at the S-locus and fitness in small self-incompatible populations. A genetic model including an S-locus and a viability locus was developed to perform forward simulations of the evolution of populations of various sizes. Drift combined with partial asexuality produced a decrease in the number of alleles at the S-locus. In addition, an excess of heterozygotes was present in the population, causing an increase in mutation load. This heterozygote excess was enhanced by the self-incompatibility system in small populations. In addition, in highly asexual populations, individuals produced asexually had some fitness advantages over individuals produced sexually, because sexual reproduction produces homozygotes of the deleterious allele, contrary to asexual reproduction. Our results suggest that future research on the function of asexuality for the maintenance of self-incompatibility will need to (1) account for whole-genome fitness (mutation load generated by asexuality, self-incompatibility and drift) and (2) acknowledge that the maintenance of self-incompatibility may not be independent of the maintenance of sex itself.

  17. Comparative effect of fixed dose combination of Amlodipine + Bisoprolol versus Amlodipine and Bisoprolol alone on blood pressure in stage-2 essential hypertensive patients.

    Directory of Open Access Journals (Sweden)

    Shirure PA,Tadvi NA, Bajait CS, Baig MS, Gade PR

    2012-09-01

    Full Text Available Background: Employment of low dose combinations of two antihypertensives, with different mode of action has gained acceptance worldwide for the treatment of mild to moderate hypertension. However, most studies in hypertensive disease have focused on monotherapy. The combination therapy in the treatment of hypertension is largely extrapolated from these monotherapy studies. Objectives: To study and compare the effect of amlodipine, bisoprolol and fixed dose combination of amlodipine + bisoprolol on blood pressure in stage-2 essential hypertensive patients. Methods: The present study was carried out in Department of Pharmacology in collaboration with Department of Medicine at Government Medical College and Hospital, Aurangabad. Results and Conclusion : Amlodipine + bisoprolol in fixed dose combination have showed significant blood pressure control in patients of stage-2 essential hypertension and the antihypertensive effect was greater than individual monotherapy study groups.

  18. Distinct patterns of blood-stage parasite antigens detected by plasma IgG subclasses from individuals with different level of exposure to Plasmodium falciparum infections

    DEFF Research Database (Denmark)

    Olesen, Cathrine Holm; Brahimi, Karima; Vandahl, Brian;

    2010-01-01

    ABSTRACT: BACKGROUND: In endemic regions naturally acquired immunity against Plasmodium falciparum develops as a function of age and exposure to parasite infections and is known to be mediated by IgG. The targets of protective antibodies remain to be fully defined. Several immunoepidemiological...... then gradually develop into protective response dominated by cytophilic IgG1 and IgG3 antibodies. METHODS: Naturally occurring IgG antibodies against P. falciparum blood-stage antigens were analysed from plasma samples collected from four groups of individuals differing in age and level of exposure to P....... falciparum infections. Western Blot profiling of blood-stage parasite antigens displaying reactivity with individual plasma samples in terms of their subclass specificities was conducted. Parasite antigens detected by IgG were grouped based on their apparent molecular sizes resolved by SDS-PAGE as high...

  19. Efficient monitoring of blood-stage infection in a malaria rodent model by the rotating-crystal magneto-optical method

    CERN Document Server

    Orban, Agnes; Albuquerque, Inês S; Butykai, Adam; Kezsmarki, Istvan; Hänscheid, Thomas

    2015-01-01

    Global research efforts have been focused on the simultaneous improvement of the efficiency and sensitivity of malaria diagnosis in resource-limited settings and for the active case detection of asymptomatic infections. A recently developed magneto-optical (MO) method allows the high-sensitivity detection of malaria pigment (hemozoin) crystals in blood via their magnetically induced rotational motion. The evaluation of the method using synthetic $\\beta$-hematin crystals and P. falciparum in vitro cultures implies its potential for in-field diagnosis. Here, we study the performance of the method in monitoring the in vivo onset and progression of the blood stage infection using a malaria mouse model. We found that the MO method can detect the first generation of intraerythrocytic parasites at the ring stage 61-66 hours after sporozoite injection demonstrating better sensitivity than light microscopy and flow cytometry. MO measurements performed after treatment of severe P. berghei infections show that the clear...

  20. Recombinant viral-vectored vaccines expressing Plasmodium chabaudi AS apical membrane antigen 1: mechanisms of vaccine-induced blood-stage protection.

    Science.gov (United States)

    Biswas, Sumi; Spencer, Alexandra J; Forbes, Emily K; Gilbert, Sarah C; Holder, Anthony A; Hill, Adrian V S; Draper, Simon J

    2012-05-15

    Apical membrane Ag 1 (AMA1) is one of the leading candidate Ags for inclusion in a subunit vaccine against blood-stage malaria. However, the efficacy of Ab-inducing recombinant AMA1 protein vaccines in phase IIa/b clinical trials remains disappointing. In this article, we describe the development of recombinant human adenovirus serotype 5 and modified vaccinia virus Ankara vectors encoding AMA1 from the Plasmodium chabaudi chabaudi strain AS. These vectors, when used in a heterologous prime-boost regimen in BALB/c mice, are capable of inducing strong transgene-specific humoral and cellular immune responses. We show that this vaccination regimen is protective against a nonlethal P. chabaudi chabaudi strain AS blood-stage challenge, resulting in reduced peak parasitemias. The role of vaccine-induced, AMA1-specific Abs and T cells in mediating the antiparasite effect was investigated by in vivo depletion of CD4(+) T cells and adoptive-transfer studies into naive and immunodeficient mice. Depletion of CD4(+) T cells led to a loss of vaccine-induced protection. Adoptive-transfer studies confirmed that efficacy is mediated by both CD4(+) T cells and Abs functioning in the context of an intact immune system. Unlike previous studies, these results confirm that Ag-specific CD4(+) T cells, induced by a clinically relevant vaccine-delivery platform, can make a significant contribution to vaccine blood-stage efficacy in the P. chabaudi model. Given that cell-mediated immunity may also contribute to parasite control in human malaria, these data support the clinical development of viral-vectored vaccines that induce both T cell and Abs against Plasmodium falciparum blood-stage malaria Ags like AMA1.

  1. A high force of plasmodium vivax blood-stage infection drives the rapid acquisition of immunity in papua new guinean children.

    Directory of Open Access Journals (Sweden)

    Cristian Koepfli

    Full Text Available BACKGROUND: When both parasite species are co-endemic, Plasmodium vivax incidence peaks in younger children compared to P. falciparum. To identify differences in the number of blood stage infections of these species and its potential link to acquisition of immunity, we have estimated the molecular force of blood-stage infection of P. vivax ((molFOB, i.e. the number of genetically distinct blood-stage infections over time, and compared it to previously reported values for P. falciparum. METHODS: P. vivax (molFOB was estimated by high resolution genotyping parasites in samples collected over 16 months in a cohort of 264 Papua New Guinean children living in an area highly endemic for P. falciparum and P. vivax. In this cohort, P. vivax episodes decreased three-fold over the age range of 1-4.5 years. RESULTS: On average, children acquired 14.0 new P. vivax blood-stage clones/child/year-at-risk. While the incidence of clinical P. vivax illness was strongly associated with mol FOB (incidence rate ratio (IRR = 1.99, 95% confidence interval (CI95 [1.80, 2.19], (molFOB did not change with age. The incidence of P. vivax showed a faster decrease with age in children with high (IRR = 0.49, CI95 [0.38, 0.64] p<0.001 compared to those with low exposure (IRR = 0.63, CI95[0.43, 0.93] p = 0.02. CONCLUSION: P. vivax (molFOB is considerably higher than P. falciparum (molFOB (5.5 clones/child/year-at-risk. The high number of P. vivax clones that infect children in early childhood contribute to the rapid acquisition of immunity against clinical P. vivax malaria.

  2. Novel measurement of blood velocity profile using translating-stage optical method and theoretical modeling based on non-Newtonian viscosity model

    Science.gov (United States)

    Kim, Chang-Beom; Lim, Jaeho; Hong, Hyobong; Kresh, J. Yasha; Wootton, David M.

    2015-07-01

    Detailed knowledge of the blood velocity distribution over the cross-sectional area of a microvessel is important for several reasons: (1) Information about the flow field velocity gradients can suggest an adequate description of blood flow. (2) Transport of blood components is determined by the velocity profiles and the concentration of the cells over the cross-sectional area. (3) The velocity profile is required to investigate volume flow rate as well as wall shear rate and shear stress which are important parameters in describing the interaction between blood cells and the vessel wall. The present study shows the accurate measurement of non-Newtonian blood velocity profiles at different shear rates in a microchannel using a novel translating-stage optical method. Newtonian fluid velocity profile has been well known to be a parabola, but blood is a non-Newtonian fluid which has a plug flow region at the centerline due to yield shear stress and has different viscosities depending on shear rates. The experimental results were compared at the same flow conditions with the theoretical flow equations derived from Casson non-Newtonian viscosity model in a rectangular capillary tube. And accurate wall shear rate and shear stress were estimated for different flow rates based on these velocity profiles. Also the velocity profiles were modeled and compared with parabolic profiles, concluding that the wall shear rates were at least 1.46-3.94 times higher than parabolic distribution for the same volume flow rate.

  3. Relationship of gelatinases-tight junction proteins and blood-brain barrier permeability in the early stage of cerebral ischemia and reperfusion

    Institute of Scientific and Technical Information of China (English)

    Haolin Xin; Wenzhao Liang; Jing Mang; Lina Lin; Na Guo; Feng Zhang; Zhongxin Xu

    2012-01-01

    Gelatinases matrix metalloproteinase-2 and matrix metalloproteinase-9 have been shown to mediate claudin-5 and occludin degradation, and play an important regulatory role in blood-brain barrier permeability. This study established a rat model of 1.5-hour middle cerebral artery occlusion with reperfusion. Protein expression levels of claudin-5 and occludin gradually decreased in the early stage of reperfusion, which corresponded to the increase of the gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9. In addition, rats that received treatment with matrix metalloproteinase inhibitor N-[(2R)-2-(hydroxamidocarbonylmethyl)-4-methylpenthanoyl]-L- tryptophan methylamide (GM6001) showed a significant reduction in Evans blue leakage and an inhibition of claudin-5 and occludin protein degradation in striatal tissue. These data indicate that matrix metalloproteinase-2 and matrix metalloproteinase-9-mediated claudin-5 and occludin degradation is an important reason for blood-brain barrier leakage in the early stage of reperfusion. The leakage of the blood-brain barrier was present due to gelatinases-mediated degradation of claudin-5 and occludin proteins. We hypothesized that the timely closure of the structural component of the blood-brain barrier (tight junction proteins) is of importance.

  4. Origin, divergence, and phylogeny of asexual Epichloë endophyte in Elymus species from western China.

    Science.gov (United States)

    Song, Hui; Nan, Zhibiao

    2015-01-01

    Asexual Epichloë species are likely derived directly from sexual Epichloë species that then lost their capacity for sexual reproduction or lost sexual reproduction because of interspecific hybridization between distinct lineages of sexual Epichloë and/or asexual Epichloë species. In this study we isolated asexual Epichloë endophytes from Elymus species in western China and sequenced intron-rich regions in the genes encoding β-tubulin (tubB) and translation elongation factor 1-α (tefA). Our results showed that there are no gene copies of tubB and tefA in any of the isolates. Phylogenetic analysis showed that sequences in this study formed a single clade with asexual Epichloë bromicola from Hordeum brevisubulatum, which implies asexual Epichloë endophytes that are symbionts in a western Chinese Elymus species likely share a common ancestor with asexual E. bromicola from European H. brevisubulatum. In addition, our results revealed that asexual E. bromicola isolates that are symbionts in a western Chinese Elymus species and sexual Epichloë species that are symbionts in a North American Elymus species have a different origin. Further analysis found that Epichloë species likely originated in Eurasia. In addition, the results support the hypothesis that migratory birds or humans might have aided the dispersal of these fungal endophytes to other continents.

  5. Origin, divergence, and phylogeny of asexual Epichloe endophyte in Elymus species from western China.

    Directory of Open Access Journals (Sweden)

    Hui Song

    Full Text Available Asexual Epichloë species are likely derived directly from sexual Epichloë species that then lost their capacity for sexual reproduction or lost sexual reproduction because of interspecific hybridization between distinct lineages of sexual Epichloë and/or asexual Epichloë species. In this study we isolated asexual Epichloë endophytes from Elymus species in western China and sequenced intron-rich regions in the genes encoding β-tubulin (tubB and translation elongation factor 1-α (tefA. Our results showed that there are no gene copies of tubB and tefA in any of the isolates. Phylogenetic analysis showed that sequences in this study formed a single clade with asexual Epichloë bromicola from Hordeum brevisubulatum, which implies asexual Epichloë endophytes that are symbionts in a western Chinese Elymus species likely share a common ancestor with asexual E. bromicola from European H. brevisubulatum. In addition, our results revealed that asexual E. bromicola isolates that are symbionts in a western Chinese Elymus species and sexual Epichloë species that are symbionts in a North American Elymus species have a different origin. Further analysis found that Epichloë species likely originated in Eurasia. In addition, the results support the hypothesis that migratory birds or humans might have aided the dispersal of these fungal endophytes to other continents.

  6. 浅析血液生化检测各阶段质控对策%Analysis of the various stages of quality control blood biochemical detection countermeasures

    Institute of Scientific and Technical Information of China (English)

    王光让; 李婷; 刘宁

    2013-01-01

    Objective To investigate the effects of the various stages of quality control sample pass rate of biochemical tests of blood. Methods Patients in February 2013 -2014 February 422 routine blood biochemical examination of the hospital for the study. order by patients admitted to hospital will be divided into a control group (n = 211) and experimental group (n = 211). The control group received routine blood chemistry testing. Experimental group at all stages of biochemical strict quality control testing. Compare two samples of blood biochemical test pass rate case. Results The control group of blood samples biochemical detection rate of 84.36% passing (178/211), the experimental group 98.58% (208/211), blood biochemistry experimental group was significantly higher pass rate specimens (P <0.01). Conclusion The various stages of quality control can significantly improve the pass rate of clinical specimens of blood biochemical tests provide a reliable basis for clinical diagnosis and treatment.%目的:探讨各阶段质控对血液生化检测标本合格率的影响。方法选取我院2013年2月至2013年8月422例行血生化检查的患者作为研究对象。按患者入院顺序,将其分为对照组(n=211)和实验组(n=211)。对照组接受常规血生化检测。实验组对血生化检测的各个阶段进行严格质控。对比两组血生化检测标本合格率情况。结果对照组血生化检测标本合格率84.36%(178/211),实验组98.58%(208/211),实验组血生化检测标本合格率显著高于对照组(P<0.01)。结论各阶段质控可显著提高临床血生化检测标本的合格率,为临床诊断及治疗提供可靠依据。

  7. Complete blood counts, liver function tests, and chest x-rays as routine screening in early-stage breast cancer: value added or just cost?

    Science.gov (United States)

    Louie, Raphael J; Tonneson, Jennifer E; Gowarty, Minda; Goodney, Philip P; Barth, Richard J; Rosenkranz, Kari M

    2015-11-01

    Current National Comprehensive Cancer Network guidelines for breast cancer staging include pre-treatment complete blood count (CBC) and liver function tests (LFT) to screen for occult metastatic disease. To date, the relevance of these tests in detecting metastatic disease in asymptomatic women with early-stage breast cancer (Stage I/II) has not been demonstrated. Although chest x-rays are no longer recommended in the NCCN guidelines, many centers continue to include this imaging as part of their screening process. We aim to determine the clinical and financial impact of these labs and x-rays in the evaluation of early-stage breast cancer patients. A single institution IRB-approved retrospective chart review was conducted of patients with biopsy-proven invasive breast cancer treated from January 1, 2005–December 31, 2009. We collected patient demographics, clinical and pathologic staging, chest x-ray, CBC, and LFT results at the time of referral. Patients were stratified according to radiographic stage at the time of diagnosis. We obtained Medicare reimbursement fees for cost analysis. From 2005 to 2009, 1609 patients with biopsy-proven invasive breast cancer were treated at our institution. Of the 1082 patients with radiographic stage I/II disease, 27.3 % of patients had abnormal CBCs. No additional testing was performed to evaluate these abnormalities. In the early-stage population, 24.7 % of patients had elevated LFTs, resulting in 84 additional imaging studies. No metastatic disease was detected. The cost of CBC, LFTs and chest x-rays was $110.20 per patient, totaling $106,410.99. Additional tests prompted by abnormal results cost $58,143.30 over the five-year period. We found that pre-treatment CBCs, LFTs, and chest x-rays did not improve detection of occult metastatic disease but resulted in additional financial costs. Avoiding routine ordering of these tests would save the US healthcare system $25.7 million annually.

  8. The paf gene product modulates asexual development in Penicillium chrysogenum.

    Science.gov (United States)

    Hegedüs, Nikoletta; Sigl, Claudia; Zadra, Ivo; Pócsi, Istvan; Marx, Florentine

    2011-06-01

    Penicillium chrysogenum secretes a low molecular weight, cationic and cysteine-rich protein (PAF). It has growth inhibitory activity against the model organism Aspergillus nidulans and numerous zoo- and phytopathogenic fungi but shows only minimal conditional antifungal activity against the producing organism itself. In this study we provide evidence for an additional function of PAF which is distinct from the antifungal activity against putative ecologically concurrent microorganisms. Our data indicate that PAF enhances conidiation in P. chrysogenum by modulating the expression of brlA, the central regulatory gene for mitospore development. A paf deletion strain showed a significant impairment of mitospore formation which sustains our hypothesis that PAF plays an important role in balancing asexual differentiation in P. chrysogenum.

  9. Use of a selective inhibitor to define the chemotherapeutic potential of the plasmodial hexose transporter in different stages of the parasite's life cycle.

    Science.gov (United States)

    Slavic, Ksenija; Delves, Michael J; Prudêncio, Miguel; Talman, Arthur M; Straschil, Ursula; Derbyshire, Elvira T; Xu, Zhengyao; Sinden, Robert E; Mota, Maria M; Morin, Christophe; Tewari, Rita; Krishna, Sanjeev; Staines, Henry M

    2011-06-01

    During blood infection, malarial parasites use D-glucose as their main energy source. The Plasmodium falciparum hexose transporter (PfHT), which mediates the uptake of D-glucose into parasites, is essential for survival of asexual blood-stage parasites. Recently, genetic studies in the rodent malaria model, Plasmodium berghei, found that the orthologous hexose transporter (PbHT) is expressed throughout the parasite's development within the mosquito vector, in addition to being essential during intraerythrocytic development. Here, using a D-glucose-derived specific inhibitor of plasmodial hexose transporters, compound 3361, we have investigated the importance of D-glucose uptake during liver and transmission stages of P. berghei. Initially, we confirmed the expression of PbHT during liver stage development, using a green fluorescent protein (GFP) tagging strategy. Compound 3361 inhibited liver-stage parasite development, with a 50% inhibitory concentration (IC₅₀) of 11 μM. This process was insensitive to the external D-glucose concentration. In addition, compound 3361 inhibited ookinete development and microgametogenesis, with IC₅₀s in the region of 250 μM (the latter in a D-glucose-sensitive manner). Consistent with our findings for the effect of compound 3361 on vector parasite stages, 1 mM compound 3361 demonstrated transmission blocking activity. These data indicate that novel chemotherapeutic interventions that target PfHT may be active against liver and, to a lesser extent, transmission stages, in addition to blood stages.

  10. Asexual and sexual reproductive strategies in clonal plants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yufen; ZHANG Dayong

    2007-01-01

    Most plants can reproduce both sexually and asexually (or vegetatively),and the balance between the two reproductive modes may vary widely between and within species.Extensive clonal growth may affect the evolution of life history traits in many ways.First,in some clonal species,sexual reproduction and sex ratio vary largely among populations.Variation in sexual reproduction may strongly affect plant's adaptation to local environments and the evolution of the geographic range.Second,clonal growth can increase floral display,and thus pollinator attraction,while it may impose serious constraints and evolutionary challenges on plants through geitonogamy that may strongly influence pollen dispersal.Geitonogamous pollination can bring a cost to plant fitness through both female and male functions.Some co-evolutionary interactions,therefore,may exist between the spatial structure and the mating behavior of clonal plants.Finally,a trade-off may exist between sexual reproduction and clonal growth.Resource allocation to the two reproductive modes may depend on environmental conditions,competitive dominance,life span,and genetic factors.If different reproductive modes represent adaptive strategies for plants in different environments,we expect that most of the resources should be allocated to sexual reproduction in habitats with fluctuating environmental conditions and strong competition,while clonal growth should be dominant in stable habitats.Yet we know little about the consequence of natural selection on the two reproductive modes and factors which control the balance of the two reproductive modes.Future studies should investigate the reproductive strategies of clonal plants simultaneously from both sexual and asexual perspectives.

  11. A novel Pfs38 protein complex on the surface of Plasmodium falciparum blood-stage merozoites

    DEFF Research Database (Denmark)

    Paul, Gourab; Deshmukh, Arunaditya; Kaur, Inderjeet;

    2017-01-01

    BACKGROUND: The Plasmodium genome encodes for a number of 6-Cys proteins that contain a module of six cysteine residues forming three intramolecular disulphide bonds. These proteins have been well characterized at transmission as well as hepatic stages of the parasite life cycle. In the present s...

  12. Natural epigenetic variation contributes to heritable flowering divergence in a widespread asexual dandelion lineage

    NARCIS (Netherlands)

    Wilschut, Rutger; Oplaat, C.; Snoek, L.B.; Kirschner, J.; Verhoeven, K.J.F.

    2016-01-01

    Epigenetic variation has been proposed to contribute to the success of asexual plants, either as a contributor to phenotypic plasticity or by enabling transient adaptation via selection on transgenerationally stable, but reversible, epialleles. While recent studies in experimental plant populations

  13. Stem cell system in asexual and sexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelida).

    Science.gov (United States)

    Yoshida-Noro, Chikako; Tochinai, Shin

    2010-01-01

    Enchytraeus japonensis is a small oligochaete species that proliferates asexually via fragmentation and regeneration. As sexual reproduction can also be induced, it is a good model system for the study of both regenerative and germline stem cells. It has been shown by histological study that putative mesodermal stem cells called neoblasts, and dedifferentiated epidermal and endodermal cells are involved in blastema formation. Recently, we isolated three region-specific marker genes expressed in the digestive tract and showed by in situ hybridization that morphallactic as well as epimorphic regulation of the body patterning occurs during regeneration. We also cloned two vasa-related genes and analyzed their expression during development and in mature worms that undergo sexual reproduction. The results arising form these studies suggest that the origin and development of germline stem cells and neoblasts may be independent. Furthermore, we carried out functional analysis using RNA interference (RNAi) and showed that a novel gene termed grimp is required for mesodermal cell proliferation at the initial stages of regeneration. These findings indicate that the stem cell system in E. japonensis is regulated by both internal and external environmental factors.

  14. Recombination in Glomus intraradices, a supposed ancient asexual arbuscular mycorrhizal fungus

    Directory of Open Access Journals (Sweden)

    Sanders Ian R

    2009-01-01

    Full Text Available Abstract Background Arbuscular mycorrhizal fungi (AMF are important symbionts of most plant species, promoting plant diversity and productivity. This symbiosis is thought to have contributed to the early colonisation of land by plants. Morphological stasis over 400 million years and the lack of an observed sexual stage in any member of the phylum Glomeromycota led to the controversial suggestion of AMF being ancients asexuals. Evidence for recombination in AMF is contradictory. Results We addressed the question of recombination in the AMF Glomus intraradices by sequencing 11 polymorphic nuclear loci in 40 morphologically identical isolates from one field. Phylogenetic relationships among genotypes showed a reticulate network pattern providing a rationale to test for recombination. Five statistical tests predicted multiple recombinant regions in the genome of a core set of isolates. In contrast, five clonal lineages had fixed a large number of differences. Conclusion Our data show that AMF from one field have undergone recombination but that clonal lineages coexist. This finding has important consequences for understanding AMF evolution, co-evolution of AMF and plants and highlights the potential for commercially introduced AMF inoculum recombining with existing local populations. Finally, our results reconcile seemingly contradictory studies on whether AMF are clonal or form recombining populations.

  15. T-cell depletion and autologous stem cell transplantation in the management of tumour stage mycosis fungoides with peripheral blood involvement.

    Science.gov (United States)

    Olavarria, E; Child, F; Woolford, A; Whittaker, S J; Davis, J G; McDonald, C; Chilcott, S; Spittle, M; Grieve, R J; Stewart, S; Apperley, J F; Russell-Jones, R

    2001-09-01

    Nine patients with tumour stage mycosis fungoides (MF) have been entered into a pilot study of T-cell depletion and autologous stem cell transplantation (SCT). Eight patients had detectable rearrangements of the T-cell receptor (TCR) gamma-gene demonstrated by polymerase chain reaction (PCR)/single-stranded conformation polymorphism (SSCP) in the peripheral blood. The median age was 47 years and the median duration of disease before SCT was 61 months; Peripheral blood progenitor cells were mobilized using high-dose etoposide (1.6 g/m2) and granulocyte colony-stimulating factor (G-CSF). The apheresis products underwent rigorous T-cell depletion with immunomagnetic methods. Double CD34-positive and CD4/CD8-negative selection achieved a median reduction of 3.89 log of T cells. All nine patients have been transplanted. Conditioning included carmustine (BCNU), etoposide and melphalan (BEM) in seven patients and total body irradiation plus etoposide or melphalan in two. Eight patients engrafted promptly and one patient died of septicaemia. All survivors entered complete remission. Seven patients have relapsed at a median of 7 months (2-14) post SCT. However, most patients have relapsed into a less aggressive stage, which has responded to conventional therapy. Four out of seven evaluable patients had detectable TCR rearrangements in the T-cell depleted graft. A T-cell clone was also detected in the peripheral blood before relapse in four cases. Autologous SCT is feasible, safe and can result in complete remission in a significant proportion of patients with tumour stage mycosis fungoides. Despite a short relapse-free survival, most patients achieved good disease control at the time of relapse.

  16. A randomized controlled trial comparing the effects of yoga with an active control on ambulatory blood pressure in individuals with prehypertension and stage 1 hypertension.

    Science.gov (United States)

    Hagins, Marshall; Rundle, Andrew; Consedine, Nathan S; Khalsa, Sat Bir S

    2014-01-01

    The purpose of this study was to compare the effects of yoga with an active control (nonaerobic exercise) in individuals with prehypertension and stage 1 hypertension. A randomized clinical trial was performed using two arms: (1) yoga and (2) active control. Primary outcomes were 24-hour day and night ambulatory systolic and diastolic blood pressures. Within-group and between-group analyses were performed using paired t tests and repeated-measures analysis of variance (time × group), respectively. Eighty-four participants enrolled, with 68 participants completing the trial. Within-group analyses found 24-hour diastolic, night diastolic, and mean arterial pressure all significantly reduced in the yoga group (-3.93, -4.7, -4.23 mm Hg, respectively) but no significant within-group changes in the active control group. Direct comparisons of the yoga intervention with the control group found a single blood pressure variable (diastolic night) to be significantly different (P=.038). This study has demonstrated that a yoga intervention can lower blood pressure in patients with mild hypertension. Although this study was not adequately powered to show between-group differences, the size of the yoga-induced blood pressure reduction appears to justify performing a definitive trial of this intervention to test whether it can provide meaningful therapeutic value for the management of hypertension.

  17. Azilsartan medoxomil plus chlorthalidone reduces blood pressure more effectively than olmesartan plus hydrochlorothiazide in stage 2 systolic hypertension.

    Science.gov (United States)

    Cushman, William C; Bakris, George L; White, William B; Weber, Michael A; Sica, Domenic; Roberts, Andrew; Lloyd, Eric; Kupfer, Stuart

    2012-08-01

    Azilsartan medoxomil, an effective, long-acting angiotensin II receptor blocker, is a new treatment for hypertension that is also being developed in fixed-dose combinations with chlorthalidone, a potent, long-acting thiazide-like diuretic. We compared once-daily fixed-dose combinations of azilsartan medoxomil/chlorthalidone force titrated to a high dose of either 40/25 mg or 80/25 mg with a fixed-dose combination of the angiotensin II receptor blocker olmesartan medoxomil plus the thiazide diuretic hydrochlorothiazide force titrated to 40/25 mg. The design was a randomized, 3-arm, double-blind, 12-week study of 1071 participants with baseline clinic systolic blood pressure 160 to 190 mm Hg and diastolic blood pressure ≤119 mm Hg. Patients had a mean age of 57 years; 59% were men, 73% were white, and 22% were black. At baseline, mean clinic blood pressure was 165/96 mm Hg and 24-hour mean blood pressure was 150/88 mm Hg. Changes in clinic (primary end point) and ambulatory systolic blood pressures at week 12 were significantly greater in both azilsartan medoxomil/chlorthalidone arms than in the olmesartan/hydrochlorothiazide arm (Pblood pressure (mean±SE) were -42.5±0.8, -44.0±0.8, and -37.1±0.8 mm Hg, respectively. Changes in 24-hour ambulatory systolic blood pressure were -33.9±0.8, -36.3±0.8, and -27.5±0.8 mm Hg, respectively. Adverse events leading to permanent drug discontinuation occurred in 7.9%, 14.5%, and 7.1% of the groups given azilsartan medoxomil/chlorthalidone 40/25 mg, azilsartan medoxomil/chlorthalidone 80/25 mg, and olmesartan/hydrochlorothiazide 40/25 mg, respectively. This large, forced-titration study has demonstrated superior antihypertensive efficacy of azilsartan medoxomil/chlorthalidone fixed-dose combinations compared with the maximum approved dose of olmesartan/hydrochlorothiazide.

  18. Targeting Angiotensin II Type-1 Receptor (AT1R) Inhibits the Harmful Phenotype of Plasmodium-Specific CD8+ T Cells during Blood-Stage Malaria

    Science.gov (United States)

    Silva-Filho, João L.; Caruso-Neves, Celso; Pinheiro, Ana A. S.

    2017-01-01

    CD8+ T-cell response is critical in the pathogenesis of cerebral malaria during blood-stage. Our group and other have been shown that angiotensin II (Ang II) and its receptor AT1 (AT1R), a key effector axis of renin-angiotensin system (RAS), have immune regulatory effects on T cells. Previously, we showed that inhibition of AT1R signaling protects mice against the lethal disease induced by Plasmodium berghei ANKA infection However, most of the Ang II/AT1R actions were characterized by using only pharmacological approaches, the effects of which may not always be due to a specific receptor blockade. In addition, the mechanisms of action of the AT1R in inducing the pathogenic activity of Plasmodium-specific CD8+ T cells during blood-stage were not determined. Here, we examined how angiotensin II/AT1R axis promotes the harmful response of Plasmodium-specific CD8+ T-cell during blood-stage by using genetic and pharmacological approaches. We evaluated the response of wild-type (WT) and AT1R−/− Plasmodium-specific CD8+ T cells in mice infected with a transgenic PbA lineage expressing ovalbumin; and in parallel infected mice receiving WT Plasmodium-specific CD8+ T cells were treated with losartan (AT1R antagonist) or captopril (ACE inhibitor). Both, AT1R−/− OT-I cells and WT OT-I cells from losartan- or captopril-treated mice showed lower expansion, reduced IL-2 production and IL-2Rα expression, lower activation (lower expression of CD69, CD44 and CD160) and lower exhaustion profiles. AT1R−/− OT-I cells also exhibit lower expression of the integrin LFA-1 and the chemokine receptors CCR5 and CXCR3, known to play a key role in the development of cerebral malaria. Moreover, AT1R−/− OT-I cells produce lower amounts of IFN-γ and TNF-α and show lower degranulation upon restimulation. In conclusion, our results show the pivotal mechanisms of AT1R-induced harmful phenotype of Plasmodium-specific CD8+ T cells during blood-stage malaria. PMID:28261571

  19. Staged treatment of a blood blister-like aneurysm with stent-assisted coiling followed by flow diverter in-stent insertion. A case report.

    Science.gov (United States)

    Princiotta, C; Dall'olio, M; Cirillo, L; Leonardi, M

    2011-09-01

    Blood blister-like aneurysms (BBLA) are rare lesions sometimes difficult to recognize and in most cases associated with diffuse subarachnoid haemorrhage and severe clinical conditions. BBLA are life-threatening because they tend to enlarge rapidly and to rebleed, and no consensus has so far been reached on the best management strategy. We describe a patient with a BBLA in the right ICA treated successful by a two-stage embolization procedure first with coils and an open cell stent (Neuroform 3) and later by further coil placement and insertion of a flow-diverting stent (Silk).

  20. The Plasmodium falciparum var gene transcription strategy at the onset of blood stage infection in a human volunteer

    DEFF Research Database (Denmark)

    Wang, Christian W; Hermsen, Cornelus C; Sauerwein, Robert W;

    2009-01-01

    The var genes encode a family of adhesion receptor proteins, Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), which profoundly influence malaria pathogenesis. Only a single var gene is transcribed and one PfEMP1 expressed per P.falciparum parasite. Here we present the in vivo...... transcript distribution of var genes in a P. falciparum-infected non-immune individual and show that the initial expression of PfEMP1 is based on a strategy that allows all or most variants of PfEMP1s to be expressed by the parasite population at the onset of the blood stage infection....

  1. Sexual versus Asexual Reproduction: Distinct Outcomes in Relative Abundance of Parthenogenetic Mealybugs following Recent Colonization.

    Science.gov (United States)

    Tabata, Jun; Ichiki, Ryoko T; Tanaka, Hirotaka; Kageyama, Daisuke

    2016-01-01

    Asexual reproduction, including parthenogenesis in which embryos develop within a female without fertilization, is assumed to confer advantages over sexual reproduction, which includes a "cost of males." Sexual reproduction largely predominates in animals, however, indicating that this cost is outweighed by the genetic and/or ecological benefits of sexuality, including the acquisition of advantageous mutations occurring in different individuals and the elimination of deleterious mutations. But the evolution of sexual reproduction remains unclear, because we have limited examples that demonstrate the relative success of sexual lineages in the face of competition from asexual lineages in the same environment. Here we investigated a sympatric occurrence of sexual and asexual reproduction in the pineapple mealybug, Dysmicoccus brevipes. This pest invaded southwestern Japan, including Okinawa and Ishigaki Islands, in the 1930s in association with imported pineapple plants. Our recent censuses demonstrated that on Okinawa sexually reproducing individuals can coexist with and even dominate asexual individuals in the presence of habitat and resource competition, which is considered to be severe for this nearly immobile insect. Molecular phylogeny based on partial DNA sequences in the mitochondrial and nuclear genomes, as well as the endosymbiotic bacterial genome, revealed that the asexual lineage diverged from a common sexual ancestor in the relatively recent past. In contrast, only the asexual lineage exhibiting obligate apomictic thelytoky was discovered on Ishigaki. Co-existence of the two lineages cannot be explained by the results of laboratory experiments, which showed that the intrinsic rate of increase in the sexual lineage was not obviously superior to that of the asexual lineage. Differences in biotic and/or abiotic selective forces operating on the two islands might be the cause of this discrepancy. This biological system offers a unique opportunity to assess

  2. Sexual versus Asexual Reproduction: Distinct Outcomes in Relative Abundance of Parthenogenetic Mealybugs following Recent Colonization.

    Directory of Open Access Journals (Sweden)

    Jun Tabata

    Full Text Available Asexual reproduction, including parthenogenesis in which embryos develop within a female without fertilization, is assumed to confer advantages over sexual reproduction, which includes a "cost of males." Sexual reproduction largely predominates in animals, however, indicating that this cost is outweighed by the genetic and/or ecological benefits of sexuality, including the acquisition of advantageous mutations occurring in different individuals and the elimination of deleterious mutations. But the evolution of sexual reproduction remains unclear, because we have limited examples that demonstrate the relative success of sexual lineages in the face of competition from asexual lineages in the same environment. Here we investigated a sympatric occurrence of sexual and asexual reproduction in the pineapple mealybug, Dysmicoccus brevipes. This pest invaded southwestern Japan, including Okinawa and Ishigaki Islands, in the 1930s in association with imported pineapple plants. Our recent censuses demonstrated that on Okinawa sexually reproducing individuals can coexist with and even dominate asexual individuals in the presence of habitat and resource competition, which is considered to be severe for this nearly immobile insect. Molecular phylogeny based on partial DNA sequences in the mitochondrial and nuclear genomes, as well as the endosymbiotic bacterial genome, revealed that the asexual lineage diverged from a common sexual ancestor in the relatively recent past. In contrast, only the asexual lineage exhibiting obligate apomictic thelytoky was discovered on Ishigaki. Co-existence of the two lineages cannot be explained by the results of laboratory experiments, which showed that the intrinsic rate of increase in the sexual lineage was not obviously superior to that of the asexual lineage. Differences in biotic and/or abiotic selective forces operating on the two islands might be the cause of this discrepancy. This biological system offers a unique

  3. Toxic effects of bisphenol A on sexual and asexual reproduction in Hydra oligactis.

    Science.gov (United States)

    Fukuhori, N; Kitano, M; Kimura, H

    2005-05-01

    Hydra oligactis, an evolutionarily primitive invertebrate, produced eggs or testes (sexual reproduction) when starved at 10 degrees C, and produced buds (asexual reproduction) when fed at 20 degrees C. Bisphenol A (BPA) at 2-4 mg/L given to male or female hydra had adverse effects on both sexual and asexual reproduction. Despite the estrogenic nature of BPA, testis formation and egg formation were similarly affected. The doses causing these acute toxicities were comparable to those reported earlier in aquatic invertebrates and were much higher than environmentally detected doses, at which the disruption of the endocrine system has been reported in fishes. All these facts indicate that the adverse effects are the results of general toxicity and may not be due to the estrogenic function of the compound. On the other hand, we found that BPA at 1 mg/L (a dose still much higher than environmental doses) stimulated asexual reproduction. No such stimulation of sexual reproduction was seen. When male hydras were fed at 10 degrees C, they produced both buds and testes simultaneously. BPA at 0.5 and 1 mg/L under this condition also stimulated asexual reproduction, whereas it suppressed sexual reproduction more severely than BPA at 2-3 mg/L. There may be some interaction between processes involved in sexual and asexual reproduction under this condition, and the stimulation of asexual reproduction by BPA may cause suppression of sexual reproduction.

  4. Impacts of acupuncture on blood pressure and hematoma in patients of cerebral hemorrhage at the early stage

    Institute of Scientific and Technical Information of China (English)

    陶文强

    2014-01-01

    Objective To explore the therapeutic effect of acupuncture for hypertensive cerebral hemorrhage at the early stage.Methods Fifty-four cases of small-amount cerebral hemorrhage were randomized into an acupuncture group and a conventional treatment group,27 cases in each.In the conventional treatment group,special care,oxygen therapy,nerve nutrition and symptomatic support were applied.If necessary,dehydrant and hypotensive drugs were prescribed for antihypertension,or surgery

  5. Three-dimensional visualisation of developmental stages of an apicomplexan fish blood parasite in its invertebrate host

    Directory of Open Access Journals (Sweden)

    Hayes Polly M

    2011-11-01

    Full Text Available Abstract Background Although widely used in medicine, the application of three-dimensional (3D imaging to parasitology appears limited to date. In this study, developmental stages of a marine fish haemogregarine, Haemogregarina curvata (Apicomplexa: Adeleorina, were investigated in their leech vector, Zeylanicobdella arugamensis; this involved 3D visualisation of brightfield and confocal microscopy images of histological sections through infected leech salivary gland cells. Findings 3D assessment demonstrated the morphology of the haemogregarine stages, their spatial layout, and their relationship with enlarged host cells showing reduced cellular content. Haemogregarine meronts, located marginally within leech salivary gland cells, had small tail-like connections to the host cell limiting membrane; this parasite-host cell interface was not visible in two-dimensional (2D light micrographs and no records of a similar connection in apicomplexan development have been traced. Conclusions This is likely the first account of the use of 3D visualisation to study developmental stages of an apicomplexan parasite in its invertebrate vector. Elucidation of the extent of development of the haemogregarine within the leech salivary cells, together with the unusual connections between meronts and the host cell membrane, illustrates the future potential of 3D visualisation in parasite-vector biology.

  6. Estimated aortic blood pressure based on radial artery tonometry underestimates directly measured aortic blood pressure in patients with advancing chronic kidney disease staging and increasing arterial stiffness

    DEFF Research Database (Denmark)

    Carlsen, Rasmus K; Peters, Christian D; Khatir, Dinah S;

    2016-01-01

    we compared invasive aortic systolic BP (SBP) with estimated central SBP obtained by radial artery tonometry and examined the influence of renal function and arterial stiffness on this relationship. We evaluated 83 patients with stage 3 to 5 CKD (mean estimated glomerular filtration rate [eGFR] 30 ml......% confidence interval -14.9 to -11.4) mm Hg. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cf-PWV) and was significantly increased in CKD patients compared with (versus) control patients (mean 10.7 vs. 9.3 m/s). The difference in BP significantly increased 1.0 mm Hg for every 10 ml....../min decrease in eGFR and by 1.6 mm Hg per 1 m/s increase in cfPWV. Using multivariate regression analysis including both eGFR and cfPWV, the difference between estimated central and invasive aortic SBP was significantly increased by 0.7 mm Hg. For the entire cohort brachial SBP significantly better reflected...

  7. Regulatory T cells in dogs with multicentric lymphoma: peripheral blood quantification at diagnosis and after initial stage chemotherapy

    Directory of Open Access Journals (Sweden)

    T.D. Munhoz

    2016-02-01

    Full Text Available Lymphoma is the most common hematopoietic malignancy in dogs and one of the most frequent among all neoplastic diseases in this species. It can occur in several anatomical locations with distinct histological and immunophenotypes. Depending on the host immune response towards the tumor, prognosis information could be collected. Because its well established immunosuppressant, antitumor activity, the function of regulatory T cells (Tregs in canine neoplasias has been investigated. In this study, we sought to quantify, using flow cytometry, the Tregs subpopulation in peripheral blood of healthy dogs (10 and in those diagnosed with type-B (14 and type-T (8 multicentric lymphoma before (at diagnosis and after the first cycle (5-week of 19-week Madison-Wisconsin (MW protocol of chemotherapy. Our results indicated that dogs with lymphoma showed higher percentage of Tregs (18,84±2,56 when compared to healthy dogs (4,70±0,50 (P0,05. There was no difference in Tregs percentage between B-type (17,45±2,77 and T-type (21,27±5,27 lymphoma (P>0,05. With this, we conclude that canine lymphoma increases Tregs in the peripheral blood and the MW protocol of chemotherapy reduces this cell subpopulation to control values.

  8. The genetic control of apomixis: asexual seed formation.

    Science.gov (United States)

    Hand, Melanie L; Koltunow, Anna M G

    2014-06-01

    Apomixis (asexual seed formation) is the result of a plant gaining the ability to bypass the most fundamental aspects of sexual reproduction: meiosis and fertilization. Without the need for male fertilization, the resulting seed germinates a plant that develops as a maternal clone. This dramatic shift in reproductive process has been documented in many flowering plant species, although no major seed crops have been shown to be capable of apomixis. The ability to generate maternal clones and therefore rapidly fix desirable genotypes in crop species could accelerate agricultural breeding strategies. The potential of apomixis as a next-generation breeding technology has contributed to increasing interest in the mechanisms controlling apomixis. In this review, we discuss the progress made toward understanding the genetic and molecular control of apomixis. Research is currently focused on two fronts. One aims to identify and characterize genes causing apomixis in apomictic species that have been developed as model species. The other aims to engineer or switch the sexual seed formation pathway in non-apomictic species, to one that mimics apomixis. Here we describe the major apomictic mechanisms and update knowledge concerning the loci that control them, in addition to presenting candidate genes that may be used as tools for switching the sexual pathway to an apomictic mode of reproduction in crops.

  9. Ultrastructural changes during asexual multiple reproduction in Trichomonas vaginalis.

    Science.gov (United States)

    Yusof, A; Kumar, S

    2012-05-01

    Trichomonas vaginalis, a flagellated protozoan parasite, is commonly found in the genitourinary tract of humans. Its mode of reproduction has always been reported to be binary fission. The high parasite numbers seen in a relatively short period in in vitro cultures led us to believe that there must be other modes of reproduction. The present study for the first time provides transformational evidence at the ultrastructural level seen in tropohozoites of T. vaginalis undergoing a multiple asexual mode of reproduction. The findings show that the single cell with a nucleus is capable of dividing to as many as eight nuclei within the cytoplasmic body. Before the commencement of division, the nucleus remained round or ovoid in shape with condensed chromatin masses and only a few endoplasmic reticula surrounding the nucleus. During the division, the nucleus started to elongate and become irregular in shape with visible chromatin masses condensing with the accumulation of numerous endoplasmic reticula. Nuclear division gave rise to as many as eight nuclei within a cell, which could be seen to be connected by numerous endoplasmic reticula. In addition, a high number of hydrogenosomes and vacuoles can be seen in multinucleated T. vaginalis compared with single nucleated T. vaginalis. This study confirms that multiple modes of nuclear division do exist in T. vaginalis and are a precursor to progeny formation.

  10. Molecular phylogenetics and asexuality in the brine shrimp Artemia.

    Science.gov (United States)

    Baxevanis, Athanasios D; Kappas, Ilias; Abatzopoulos, Theodore J

    2006-09-01

    Explaining cases of long-term persistence of parthenogenesis has proven an arduous task for evolutionary biologists. Interpreting sexual-asexual interactions though has recently advanced owing to methodological design, increased taxon sampling and choice of model organisms. We inferred the phylogeny of Artemia, a halophilic branchiopod genus of sexual and parthenogenetic forms with cosmopolitan distribution, marked geographic patterns and ecological partitioning. Joint analysis of newly derived ITS1 sequences and 16S RFLP markers from global isolates indicates significant interspecific divergence as well as pronounced diversity for parthenogens, matching that of sexual ancestors. Maximum parsimony, maximum likelihood, and Bayesian methods were largely congruent in reconstructing the phylogeny of the genus. Given the current sampling, at least four independent origins of parthenogenesis are deduced. Molecular clock calibrations based on biogeographic landmarks indicate that the lineage leading to A. persimilis diverged from the common ancestor of all Artemia species between 80 and 90 MYA at the time of separation of Africa from South America, whereas parthenogenesis first appeared at least 3 MYA. Common mitochondrial DNA haplotypes delineate A. urmiana and A. tibetiana as possible maternal parents of several clonal lineages. A novel topological placement of A. franciscana as a sister clade to all Asian Artemia and parthenogenetic forms is proposed and also supported by ITS1 length and other existing data.

  11. Sexual and Asexual Reproduction of Salix sitchensis and the Influence of Beaver (Castor canadensis) Herbivory on Reproductive Success

    OpenAIRE

    Travis G. Gerwing; Alyssa M. Allen Gerwing; Rapaport, Eric; Alström-Rapaport, Cecilia

    2012-01-01

    The influence of beaver (Castor canadensis Kuhl) herbivory on Salix reproduction, specifically the stimulation of asexual reproduction via browsed stem fragments, is relatively unknown. This study aimed to determine if beaver herbivory stimulates asexual reproduction of riparian willows and results in mature populations dominated by clones. The survival of seedlings and asexual propagules produced by beaver browse in populations of the riparian willow Salix sitchensis (Sanson in Bongard) were...

  12. Glycoprotein and Glycan in Tissue and Blood Samples of Patients With Stage IB-IVA Cervical Cancer Undergoing Surgery to Remove Pelvic and Abdominal Lymph Nodes

    Science.gov (United States)

    2016-10-26

    Cervical Adenocarcinoma; Cervical Adenosquamous Carcinoma; Cervical Small Cell Carcinoma; Cervical Squamous Cell Carcinoma, Not Otherwise Specified; Stage IB Cervical Cancer; Stage IIA Cervical Cancer; Stage IIB Cervical Cancer; Stage III Cervical Cancer; Stage IVA Cervical Cancer

  13. Two-stage cyclic enzymatic amplification method for ultrasensitive electrochemical assay of microRNA-21 in the blood serum of gastric cancer patients.

    Science.gov (United States)

    Li, Bingchen; Liu, Fei; Peng, Yuanyuan; Zhou, Yunlei; Fan, Wenxuan; Yin, Huanshun; Ai, Shiyun; Zhang, Xiansheng

    2016-05-15

    MicroRNA (miRNA) is riveting nowadays due to its close relevance to human malignancies. Exploiting a fast and convenient biosensor for sensitive and specific detecting miRNA is necessary and it has significant meaning for oncology. In this work, to understand the relationship between miRNA-21 and gastric cancer, we employ T4 RNA ligase 2 to initiate specific ligation reaction depending on the sequence of target RNA, and T7 exonuclease to catalyze the first stage cyclic enzymatic amplification method (CEAM) specifically, which also resting on the target RNA sequence, and the second stage CEAM to further amplify the response resulting from the initial target RNA. Our two-stage CEAM strategy can detect miRNA-21 as low as 0.36fM with remarkable specificity, and most importantly, it can be used to inspect the expression level of miRNA-21 in blood serum of gastric cancer patients. This will offer new perspective for figuring out the pathways of miRNA-21 involving in cancer.

  14. Discordance between nuclear and mitochondrial genomes in sexual and asexual lineages of the freshwater snail Potamopyrgus antipodarum.

    Science.gov (United States)

    Paczesniak, Dorota; Jokela, Jukka; Larkin, Katelyn; Neiman, Maurine

    2013-09-01

    The presence and extent of mitonuclear discordance in coexisting sexual and asexual lineages provides insight into 1) how and when asexual lineages emerged, and 2) the spatial and temporal scales at which the ecological and evolutionary processes influencing the evolution of sexual and asexual reproduction occur. Here, we used nuclear single-nucleotide polymorphism (SNP) markers and a mitochondrial gene to characterize phylogeographic structure and the extent of mitonuclear discordance in Potamopyrgus antipodarum. This New Zealand freshwater snail is often used to study the evolution and maintenance of sex because obligately sexual and obligately asexual individuals often coexist. While our data indicate that sexual and asexual P. antipodarum sampled from the same lake population are often genetically similar, suggesting recent origin of these asexuals from sympatric sexual P. antipodarum, we also found significantly more population structure in sexuals vs. asexuals. This latter result suggests that some asexual lineages originated in other lakes and/or in the relatively distant past. When comparing mitochondrial and nuclear population genetic structure, we discovered that one mitochondrial haplotype ('1A') was rare in sexuals, but common and widespread in asexuals. Haplotype 1A frequency and nuclear genetic diversity were not associated, suggesting that the commonness of this haplotype cannot be attributed entirely to genetic drift and pointing instead to a role for selection.

  15. Advantage or Disadvantage: Is Asexual Reproduction Beneficial to Survival of the Tunicate, Polyandrocarpa misakiensis.

    Science.gov (United States)

    Kawamura, K; Fujiwara, S

    2000-04-01

    It has been believed that clonal propagation by asexual reproduction has serious disadvantages for long-term survival, because asexual reproduction seems not to remove harmful mutations, it seems not to give rise to genetic variations upon which evolution depends and it seems not to reset cell aging. In this article, we re-consider those arguments, by reviewing asexual reproduction of the tunicate, Polyandrocarpa misakiensis. Tracer experiments of bud formation and growth using morphological and chimeric phenotypes showed that the parental epithelial tissues surrounding the bud primordium do not enter the growing bud. It is possible, therefore, to assume that budding involves the purge of a large number of parental somatic cells and tissues. Unlike sexuals, asexuals do not carry out meiotic recombination nor gene shuffling that are two major sources of genetic variation, but we can show that in P. misakiensis at least two genes have significant redundancy and genetic variation even in a clonal colony. Telomerase expressed in germlines is thought to reset the molecular clock executed by telomere shortening. In our Polyandrocarpa cDNA projects, four out of about 2,000 cDNAs examined were matched with retroviral reverse transcriptase that is the catalytic subunit of telomerase, suggesting that telomerase might work in asexual reproduction. In P. misakiensis, dedifferentiation system is used to make new asexual generations. TC14 lectin plays an important role in the maintenance of multipotent but differentiated state of the formative tissue. It is antagonized by tunicate serine protease (TRAMP) that has striking mitogenic and dedifferentiation-inducing activities on the multipotent cells. This system would serve to delay aging of somatic cells. In conclusion, empirical arguments that asexual reproduction is disadvantageous to long-term life do not appear to be tenable to budding of P. misakiensis.

  16. [Anti-alpha-gliadin antibodies. Sensitivity, specificity and correlation with blood xylose test in the 3 diagnostic stages of celiac disease in children].

    Science.gov (United States)

    Ventura, A; Florean, P; Trevisan, M; Not, T; Perticarari, S; Quadrifoglio, F; Torre, G; Cauci, S

    1987-01-01

    The specificity and sensibility of IgA and IgG alfagliadin antibody test (AaGA) for screening, diagnosis and follow-up of childhood coeliac disease has been evaluated. We have compared AaGA test to D-xylose blood test and at last we have examined the false positive and negative results given by the test. Two groups of subjects were considered: 1) 90 children with untreated coeliac disease (21 newly diagnosed (I stage), 50 in gluten withdrawal (II stage), 19 in challenge (III stage); 2) 255 disease controls including: 157 healthy controls; 31 children with gastroenterological disorders other than coeliac disease; 31 children with food allergy and atopic dermatitis; 36 children with "constitutional" short stature (without GH deficiency and with normal intestinal mucosa). The sensibility of AaGA test in the first stage of coeliac disease has been of 95.2% for the IgG class antibody and 90.4% for the IgA class; on the other hand the showed a specificity of 83.6% for IgG class antibody and 96.9% for IgA class. In only two newly diagnosed coeliac children we have found false negative results: in the first case the patient was IgA-deficient, in the second the age was above 3 years. AaGA IgA resulted positive only in the 12.9% of the group of gastroenterological and atopic controls; particularly most cases were affected by multiple food allergies and two patients by chronic autoimmune disease of small intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Compromised Blood-Brain Barrier Competence in Remote Brain Areas in Ischemic Stroke Rats at Chronic Stage

    Science.gov (United States)

    Garbuzova-Davis, Svitlana; Haller, Edward; Williams, Stephanie N.; Haim, Eithan D.; Tajiri, Naoki; Hernandez-Ontiveros, Diana G.; Frisina-Deyo, Aric; Boffeli, Sean M.; Sanberg, Paul R.; Borlongan, Cesario V.

    2014-01-01

    Stroke is a life threatening disease leading to long-term disability in stroke survivors. Cerebral functional insufficiency in chronic stroke might be due to pathological changes in brain areas remote from initial ischemic lesion, i.e. diaschisis. Previously, we showed that the damaged blood-brain barrier (BBB) was implicated in subacute diaschisis. The present study investigated BBB competence in chronic diaschisis using a transient middle cerebral artery occlusion (tMCAO) rat model. Our results demonstrated significant BBB damage mostly in the ipsilateral striatum and motor cortex in rats at 30 days after tMCAO. The BBB alterations were also determined in the contralateral hemisphere via ultrastructural and immunohistochemical analyses. Major BBB pathological changes in contralateral remote striatum and motor cortex areas included: (1) vacuolated endothelial cells containing large autophagosomes, (2) degenerated pericytes displaying mitochondria with cristae disruption, (3) degenerated astrocytes and perivascular edema, (4) Evans Blue extravasation, and (5) appearance of parenchymal astrogliosis. Importantly, discrete analyses of striatal and motor cortex areas revealed significantly higher autophagosome accumulation in capillaries of ventral striatum and astrogliosis in dorsal striatum in both cerebral hemispheres. These widespread microvascular alterations in ipsilateral and contralateral brain hemispheres suggest persistent and/or continued BBB damage in chronic ischemia. The pathological changes in remote brain areas likely indicate chronic ischemic diaschisis, which should be considered in the development of treatment strategies for stroke. PMID:24610730

  18. Analysis of stage specific protein expression during babesia bovis development within rhipicephalus microplus female ticks

    Science.gov (United States)

    Arthropod borne pathogens have a complex life cycle that includes asexual reproduction of haploid stages in mammalian erythrocytes and development of diploid stages in the vector. Transition of Apicomplexan pathogens between the mammalian host and the arthropod vector is critical for ongoing transmi...

  19. Horizontal transfer generates genetic variation in an asexual pathogen

    Directory of Open Access Journals (Sweden)

    Xiaoqiu Huang

    2014-10-01

    Full Text Available There are major gaps in the understanding of how genetic variation is generated in the asexual pathogen Verticillium dahliae. On the one hand, V. dahliae is a haploid organism that reproduces clonally. On the other hand, single-nucleotide polymorphisms and chromosomal rearrangements were found between V. dahliae strains. Lineage-specific (LS regions comprising about 5% of the genome are highly variable between V. dahliae strains. Nonetheless, it is unknown whether horizontal gene transfer plays a major role in generating genetic variation in V. dahliae. Here, we analyzed a previously sequenced V. dahliae population of nine strains from various geographical locations and hosts. We found highly homologous elements in LS regions of each strain; LS regions of V. dahliae strain JR2 are much richer in highly homologous elements than the core genome. In addition, we discovered, in LS regions of JR2, several structural forms of nonhomologous recombination, and two or three homologous sequence types of each form, with almost each sequence type present in an LS region of another strain. A large section of one of the forms is known to be horizontally transferred between V. dahliae strains. We unexpectedly found that 350 kilobases of dynamic LS regions were much more conserved than the core genome between V. dahliae and a closely related species (V. albo-atrum, suggesting that these LS regions were horizontally transferred recently. Our results support the view that genetic variation in LS regions is generated by horizontal transfer between strains, and by chromosomal reshuffling reported previously.

  20. Light-regulated asexual reproduction in Paecilomyces fumosoroseus.

    Science.gov (United States)

    Sánchez-Murillo, Rosa Icela; de la Torre-Martínez, Mayra; Aguirre-Linares, Jesús; Herrera-Estrella, Alfredo

    2004-02-01

    The entomopathogenic fungus Paecilomyces fumosoroseus has been successfully used in the control of several insect pests. Asexually produced spores (conidia) are the means for dispersal and transmission of the entomopathogen; upon contact with the insect cuticle they germinate and penetrate the host. In model fungal systems it has been found that phototropism, resetting of the circadian rhythm, the induction of carotenogenesis and the development of reproductive structures are controlled by blue light. The effect of light quality on conidial yield of P. fumosoroseus was investigated. Incubation in total darkness resulted in continued vegetative growth and lack of reproductive structures. In contrast, growth of the fungus in continuous illumination or under a night-day regime resulted in prolific formation of conidiophores bearing abundant mature conidia. Conidiation was photoinduced in competent mycelia by a single pulse of blue light and colonies were competent only after they had grown at least 72 h under total darkness. The fluence-response curves generated with blue light indicated that the minimal fluence required for the photomorphogenetic response was 180 micro mol m(-2) and the half-maximal response was at 400 micro mol m(-2). A fluence of 540 micro mol m(-2) was enough to saturate the system, inducing the maximum production of 2.12x10(8) conidia per colony. Higher light intensities markedly decreased conidiation, suggesting the occurrence of a process of adaptation. The authors propose the existence of a dual light-perception system with at least two photoreceptors in P. fumosoroseus, one promoting and one inhibiting conidiation.

  1. Neutral and selection-driven decay of sexual traits in asexual stick insects.

    Science.gov (United States)

    Schwander, Tanja; Crespi, Bernard J; Gries, Regine; Gries, Gerhard

    2013-08-07

    Environmental shifts and lifestyle changes may result in formerly adaptive traits becoming non-functional or maladaptive. The subsequent decay of such traits highlights the importance of natural selection for adaptations, yet its causes have rarely been investigated. To study the fate of formerly adaptive traits after lifestyle changes, we evaluated sexual traits in five independently derived asexual lineages, including traits that are specific to males and therefore not exposed to selection. At least four of the asexual lineages retained the capacity to produce males that display normal courtship behaviours and are able to fertilize eggs of females from related sexual species. The maintenance of male traits may stem from pleiotropy, or from these traits only regressing via drift, which may require millions of years to generate phenotypic effects. By contrast, we found parallel decay of sexual traits in females. Asexual females produced altered airborne and contact signals, had modified sperm storage organs, and lost the ability to fertilize their eggs, impeding reversals to sexual reproduction. Female sexual traits were decayed even in recently derived asexuals, suggesting that trait changes following the evolution of asexuality, when they occur, proceed rapidly and are driven by selective processes rather than drift.

  2. Infection dynamics in coexisting sexual and asexual host populations: support for the Red Queen hypothesis.

    Science.gov (United States)

    Vergara, Daniela; Jokela, Jukka; Lively, Curtis M

    2014-08-01

    The persistence of sexual reproduction is a classic problem in evolutionary biology. The problem stems from the fact that, all else equal, asexual lineages should rapidly replace coexisting sexual individuals due to the cost of producing males in sexual populations. One possible countervailing advantage to sexual reproduction is that, on average, outcrossed offspring are more resistant than common clones to coevolving parasites, as predicted under the Red Queen hypothesis. In this study, we evaluated the prevalence of infection by a sterilizing trematode (Microphallus sp.) in a natural population of freshwater snails that was composed of both sexual and asexual individuals (Potamopyrgus antipodarum). More specifically, we compared the frequency of infection in sexual and asexual individuals over a 5-year period at four sites at a natural glacial lake (Lake Alexandrina, South Island, New Zealand). We found that at most sites and over most years, the sexual population was less infected than the coexisting asexual population. Moreover, the frequency of uninfected sexual females was periodically greater than two times the frequency of uninfected asexual females. These results give clear support for a fluctuating parasite-mediated advantage to sexual reproduction in a natural population.

  3. Exploring the role of asexual multiplication in poplar rust epidemics: impact on diversity and genetic structure.

    Science.gov (United States)

    Barrès, Benoît; Dutech, Cyril; Andrieux, Axelle; Halkett, Fabien; Frey, Pascal

    2012-10-01

    Fungal plant pathogens, especially rust fungi (Pucciniales), are well known for their complex life cycles, which include phases of sexual and asexual reproduction. The effect of asexual multiplication on population genetic diversity has been investigated in the poplar rust fungus Melampsora larici-populina using a nested hierarchical sampling scheme. Four hierarchical levels were considered: leaf, twig, tree and site. Both cultivated and wild poplar stands were sampled at two time points at the start and end of rust epidemics. A total of 641 fungal isolates was analysed using nine microsatellite markers. This study revealed that the genetic signature of asexual multiplication in the wild poplar stand was seen only at lower hierarchical levels (leaf and twig). Moreover, we observed an erosion of clonal structure through time, with an increase in both gene and genotypic diversity. New genotypes contributed to host infection over time, which demonstrates the importance of allo-infection in the epidemic process in this host-pathogen system. Compared with the wild stands, the nearly lack of detection of clonal structure in the cultivated stands reflects the higher infection level on cultivated poplars. More generally, this genetic analysis illustrates the utility of population genetics approach for elucidating the proportion of asexual reproduction in the multiplication of isolates during an epidemic, and for proper quantification of asexual dispersal in plant pathogens.

  4. Environmental challenges improve resource utilization for asexual reproduction and maintenance in hydra.

    Science.gov (United States)

    Schaible, Ralf; Ringelhan, Felix; Kramer, Boris H; Miethe, Tanja

    2011-10-01

    Variation in life history can reflect genetic differences, and may be caused by environmental effects on phenotypes. Understanding how these two sources of life history variation interact to express an optimal allocation of resources in a changing environment is central to life history theory. This study addresses variation in the allocation of resources to asexual reproduction and to maintenance of Hydra magnipapillata in relation to differences in temperature and food availability. Hydra is a non-senescent, persistent species with primarily clonal reproduction. We recorded changes in budding rate and mean survival under starvation, which indicate changes in the allocation of resources to asexual reproduction and maintenance. In constant conditions we observed a clear trade-off between asexual reproduction and maintenance, where budding increased linearly with food intake while starvation survival stayed rather constant. In contrast, an environment with fluctuations in temperature or food availability promotes maintenance and increases the survival chances of hydra under starvation. Surprisingly, asexual reproduction also tends to be positively affected by fluctuating environmental conditions, which suggests that in this case there is no clear trade-off between asexual reproduction and maintenance in hydra. Environmental stresses have a beneficial impact on the fitness-related phenotypical traits of the basal metazoan hydra. The results indicate that, if the stress occurs in hormetic doses, variable stressful and fluctuating environments can be salutary for hydra. A closer examination of this dynamic can therefore enable us to develop a deeper understanding of the evolution of aging and longevity.

  5. Adaptive molecular evolution of a defence gene in sexual but not functionally asexual evening primroses.

    Science.gov (United States)

    Hersch-Green, E I; Myburg, H; Johnson, M T J

    2012-08-01

    Theory predicts that sexual reproduction provides evolutionary advantages over asexual reproduction by reducing mutational load and increasing adaptive potential. Here, we test the latter prediction in the context of plant defences against pathogens because pathogens frequently reduce plant fitness and drive the evolution of plant defences. Specifically, we ask whether sexual evening primrose plant lineages (Onagraceae) have faster rates of adaptive molecular evolution and altered gene expression of a class I chitinase, a gene implicated in defence against pathogens, than functionally asexual evening primrose lineages. We found that the ratio of amino acid to silent substitutions (K(a) /K(s) = 0.19 vs. 0.11 for sexual and asexual lineages, respectively), the number of sites identified to be under positive selection (four vs. zero for sexual and asexual lineages, respectively) and the expression of chitinase were all higher in sexual than in asexual lineages. Our results are congruent with the conclusion that a loss of sexual recombination and segregation in the Onagraceae negatively affects adaptive structural and potentially regulatory evolution of a plant defence protein.

  6. Regional cerebral blood flow in acute stage ischemic cerebrovascular disease by xenon-133 inhalation and single photon emission computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Hiroyuki (Akita Univ. (Japan). School of Medicine)

    1989-03-01

    During the period from February 1984 through June 1985, single photon emission computerized tomography (SPECT) with xenon-133 inhalation method has been performed for the measurement of regional cerebral blood flow (rCBF) during the first 48 hours of onset of cerebral infarction (n=71) and transient ischemic attack (n=21). X-ray CT (CT) and carotid arteriography were concurrently performed in all the patients. In repeated studies performed for 15 normal volunteers, rCBF measurement by SPECT was found reproducible. Mean values of rCBF for the right and left cerebral hemispheres were 60.3{plus minus}6.52 and 61.8{plus minus}6.91 ml/100 g/min, respectively. For cerebral infarction, ischemic foci corresponding to clinical symptoms were detected more frequently on SPECT than on CT (93% vs 63%). In all of the evaluable 35 patients with cerebral infarction, rCBF within the first 8 hours of onset was decreased: 31.0 ml/100 g/min for the internal carotid artery (ICA) occlusion and 36.0 ml/100 g/min for the middle cerebral artery (MCA) occlusion. Crossed cerebellar diaschisis was observed in 50% (9/18) for ICA occlusion and 37% (14/38) for MCA occlusion. For transient ischemic attack, there was no significant difference in the detection of ischemic foci between SPECT and CT (38% vs 43%). In detecting small foci especially in the deep regions such as the basal ganglia, SPECT was inferior to CT. Mean rCBF for transient ischemic attack tended to be lower than the normal rCBF (50.7 ml/100 g/min for the right cerebral hemisphere and 50.6 ml/100 g/min for the left cerebral hemisphere). SPECT may aid in predicting prognosis and chosing treatment strategy, as well as in determining cerebral hemodynamics. (N.K.).

  7. Proteomic and genetic analyses demonstrate that Plasmodium berghei blood stages export a large and diverse repertoire of proteins.

    Science.gov (United States)

    Pasini, Erica M; Braks, Joanna A; Fonager, Jannik; Klop, Onny; Aime, Elena; Spaccapelo, Roberta; Otto, Thomas D; Berriman, Matt; Hiss, Jan A; Thomas, Alan W; Mann, Matthias; Janse, Chris J; Kocken, Clemens H M; Franke-Fayard, Blandine

    2013-02-01

    Malaria parasites actively remodel the infected red blood cell (irbc) by exporting proteins into the host cell cytoplasm. The human parasite Plasmodium falciparum exports particularly large numbers of proteins, including proteins that establish a vesicular network allowing the trafficking of proteins onto the surface of irbcs that are responsible for tissue sequestration. Like P. falciparum, the rodent parasite P. berghei ANKA sequesters via irbc interactions with the host receptor CD36. We have applied proteomic, genomic, and reverse-genetic approaches to identify P. berghei proteins potentially involved in the transport of proteins to the irbc surface. A comparative proteomics analysis of P. berghei non-sequestering and sequestering parasites was used to determine changes in the irbc membrane associated with sequestration. Subsequent tagging experiments identified 13 proteins (Plasmodium export element (PEXEL)-positive as well as PEXEL-negative) that are exported into the irbc cytoplasm and have distinct localization patterns: a dispersed and/or patchy distribution, a punctate vesicle-like pattern in the cytoplasm, or a distinct location at the irbc membrane. Members of the PEXEL-negative BIR and PEXEL-positive Pb-fam-3 show a dispersed localization in the irbc cytoplasm, but not at the irbc surface. Two of the identified exported proteins are transported to the irbc membrane and were named erythrocyte membrane associated proteins. EMAP1 is a member of the PEXEL-negative Pb-fam-1 family, and EMAP2 is a PEXEL-positive protein encoded by a single copy gene; neither protein plays a direct role in sequestration. Our observations clearly indicate that P. berghei traffics a diverse range of proteins to different cellular locations via mechanisms that are analogous to those employed by P. falciparum. This information can be exploited to generate transgenic humanized rodent P. berghei parasites expressing chimeric P. berghei/P. falciparum proteins on the surface of

  8. Investment choices in post-embryonic development: quantifying interactions among growth, regeneration, and asexual reproduction in the annelid Pristina leidyi.

    Science.gov (United States)

    Zattara, Eduardo E; Bely, Alexandra E

    2013-12-01

    Animals capable of multiple forms of post-embryonic development, such as growth, regeneration, and asexual reproduction, must make choices about which processes to invest in. What strategies guide post-embryonic resource allocation investments? We investigated this question in the annelid Pristina leidyi, which can grow continuously, regenerates well, and reproduces asexually by fission. We found that in this species growth is concentrated in three zones: a subterminal posterior zone (forming new segments), a mid-body zone (forming fission zones), and a previously undescribed subterminal anterior zone at the base of the prostomium (which we suggest continually builds the prostomium through a "conveyor-belt" like process). Body-wide counts of proliferating cells are greater under high food than low food conditions but proliferation patterns themselves are independent of feeding level. Proliferation patterns are strongly affected by amputation, however, with proliferation rapidly shutting-down throughout the body, except at the wound site, following injury. Relative investment to fission and regeneration is highly context-dependent, being sensitive to the position of the cut and the stage of fission. Outcomes range from fission acceleration and regeneration stalling (high fission:regeneration investment) to resorption of fission zones and progression of regeneration (low fission:regeneration investment). Our findings reveal strong interactions between growth, regeneration, and fission and demonstrate a particularly important effect of injury on resource allocation patterns. Patterns of resource investment in P. leidyi show similarities to those described in two other groups that evolved fission independently (naidine annelids and catenulid flatworms), suggesting that similar developmental and physiological contexts may drive convergent evolution of resource allocation strategies.

  9. An anatomical description of a miniaturized acorn worm (hemichordata, enteropneusta) with asexual reproduction by paratomy.

    Science.gov (United States)

    Worsaae, Katrine; Sterrer, Wolfgang; Kaul-Strehlow, Sabrina; Hay-Schmidt, Anders; Giribet, Gonzalo

    2012-01-01

    The interstitial environment of marine sandy bottoms is a nutrient-rich, sheltered habitat whilst at the same time also often a turbulent, space-limited, and ecologically challenging environment dominated by meiofauna. The interstitial fauna is one of the most diverse on earth and accommodates miniaturized representatives from many macrofaunal groups as well as several exclusively meiofaunal phyla. The colonization process of this environment, with the restrictions imposed by limited space and low Reynolds numbers, has selected for great morphological and behavioral changes as well as new life history strategies.Here we describe a new enteropneust species inhabiting the interstices among sand grains in shallow tropical waters of the West Atlantic. With a maximum body length of 0.6 mm, it is the first microscopic adult enteropneust known, a group otherwise ranging from 2 cm to 250 cm in adult size. Asexual reproduction by paratomy has been observed in this new species, a reproductive mode not previously reported among enteropneusts. Morphologically, Meioglossus psammophilus gen. et sp. nov. shows closest resemblance to an early juvenile stage of the acorn worm family Harrimaniidae, a result congruent with its phylogenetic placement based on molecular data. Its position, clearly nested within the larger macrofaunal hemichordates, suggests that this represents an extreme case of miniaturization. The evolutionary pathway to this simple or juvenile appearance, as chiefly demonstrated by its small size, dense ciliation, and single pair of gill pores, may be explained by progenesis. The finding of M. psammophilus gen. et sp. nov. underscores the notion that meiofauna may constitute a rich source of undiscovered metazoan diversity, possibly disguised as juveniles of other species.

  10. Stem cells in asexual reproduction of Enchytraeus japonensis (Oligochaeta, Annelid): proliferation and migration of neoblasts.

    Science.gov (United States)

    Sugio, Mutsumi; Yoshida-Noro, Chikako; Ozawa, Kaname; Tochinai, Shin

    2012-05-01

    Enchytraeus japonensis is a small oligochaete that reproduces mainly asexually by fragmentation (autotomy) and regeneration. As sexual reproduction can also be induced, it is a good animal model for the study of both somatic and germline stem cells. To clarify the features of stem cells in regeneration, we investigated the proliferation and lineage of stem cells in E. japonensis. Neoblasts, which have the morphological characteristics of undifferentiated cells, were found to firmly adhere to the posterior surface of septa in each trunk segment. Also, smaller neoblast-like cells, which are designated as N-cells in this study, were located dorsal to the neoblasts on the septa. By conducting 5-bromo-2'-deoxyuridine (BrdU)-labeling-experiments, we have shown that neoblasts are slow-cycling (or quiescent) in intact growing worms, but proliferate rapidly in response to fragmentation. N-cells proliferate more actively than do neoblasts in intact worms. The results of pulse-chase experiments indicated that neoblast and N-cell lineage mesodermal cells that incorporated BrdU early in regeneration migrated toward the autotomized site to form the mesodermal region of the blastema, while the epidermal and intestinal cells also contributed to the blastema locally near the autotomized site. We have also shown that neoblasts have stem cell characteristics by expressing Ej-vlg2 and by the activity of telomerase during regeneration. Telomerase activity was high in the early stage of regeneration and correlated with the proliferation activity in the neoblast lineage of mesodermal stem cells. Taken together, our results indicate that neoblasts are mesodermal stem cells involved in the regeneration of E. japonensis.

  11. Efficient monitoring of the blood-stage infection in a malaria rodent model by the rotating-crystal magneto-optical method

    Science.gov (United States)

    Orbán, Ágnes; Rebelo, Maria; Molnár, Petra; Albuquerque, Inês S.; Butykai, Adam; Kézsmárki, István

    2016-03-01

    Intense research efforts have been focused on the improvement of the efficiency and sensitivity of malaria diagnostics, especially in resource-limited settings for the detection of asymptomatic infections. Our recently developed magneto-optical (MO) method allows the accurate quantification of malaria pigment crystals (hemozoin) in blood by their magnetically induced rotation. First evaluations of the method using β-hematin crystals and in vitro P. falciparum cultures implied its potential for high-sensitivity malaria diagnosis. To further investigate this potential, here we study the performance of the method in monitoring the in vivo onset and progression of the blood-stage infection in a rodent malaria model. Our results show that the MO method can detect the first generation of intraerythrocytic P. berghei parasites 66-76 hours after sporozoite injection, demonstrating similar sensitivity to Giesma-stained light microscopy and exceeding that of flow cytometric techniques. Magneto-optical measurements performed during and after the treatment of P. berghei infections revealed that both the follow up under treatment and the detection of later reinfections are feasible with this new technique. The present study demonstrates that the MO method - besides being label and reagent-free, automated and rapid - has a high in vivo sensitivity and is ready for in-field evaluation.

  12. No effect of human serum and erythrocytes enriched in n-3 fatty acids by oral intake on Plasmodium falciparum blood stage parasites in vitro

    DEFF Research Database (Denmark)

    Abu-Zeid, Y A; Hansen, H S; Jakobsen, P H;

    1993-01-01

    To examine the effect of n-3 polyunsaturated fatty acids (n-3 PUFA) on the erythrocytic growth of Plasmodium falciparum, serum and erythrocytes were separated from blood of a healthy donor before and after he had taken fish oil capsules for 8 days. Such intake supplied an amount of eicosapentaenoic...... acid (EPA, 20:5n-3) of 3.5 g/d and docosahexaenoic acid (DHA, 22:6n-3) of 2.5 g/d and 24 mg/d of total tocopherol. Post-intake fish oil serum (post-s) and erythrocytes (post-e) were tested in vitro for inhibitory activity against blood stages of P. falciparum compared with pre-intake serum (pre......-s) and pre-intake erythrocyte (pre-e). Also the effect of EPA and arachidonic acid (AA, 20:4n-6) on the erythrocytic growth of P. falciparum was tested using in vitro assays. The results show that both post-s and post-e had no antimalarial activity on P. falciparum. No differential antimalarial effect...

  13. Elevated global cerebral blood flow, oxygen extraction fraction and unchanged metabolic rate of oxygen in young adults with end-stage renal disease: an MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Gang; Lou, Yaxian; Pan, Zhiying; Liu, Ya [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China); Nanjing University of Aeronautics and Astronautics, College of Aivil Aviation, Nanjing, Jiangsu (China); Wen, Jiqiu; Li, Xue; Zhang, Zhe [Medical School of Nanjing University, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing, Jiangsu (China); Lu, Hanzhang [University of Texas Southwestern Medical Center, Advanced Imaging Research Center, Dallas, TX (United States); Liu, Wei [Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong (China); Liu, Hui [Siemens MR NEA Collaboration, Siemens Ltd., Shanghai (China); Chen, Huijuan; Kong, Xiang; Luo, Song; Jiang, Xiaolu; Zhang, Zongjun; Zhang, Long Jiang; Lu, Guang Ming [Medical School of Nanjing University, Department of Medical Imaging, Jinling Hospital, Nanjing, Jiangsu (China)

    2016-06-15

    To noninvasively assess global cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) in young adults with end-stage renal disease (ESRD). Thirty-six patients and 38 healthy volunteers were included and took part in MR examinations, blood and neuropsychological tests. CBF and OEF were measured by phase-contrast and T2-relaxation-under-spin-tagging MRI techniques, respectively. CMRO{sub 2} was computed from CBF, OEF and hematocrit according to Fick's principle. Correlations were performed between MR measurements, blood biochemistry measurements and neuropsychological test scores. Compared with controls, ESRD patients had elevated CBF (72.9 ± 12.5 vs. 63.8 ± 8.5 ml min{sup -1} 100 g{sup -1}, P < 0.001), elevated OEF (47.2 ± 10.2 vs. 35.8 ± 5.4 %, P < 0.001), but unaffected CMRO{sub 2} (199.5 ± 36.4 vs. 193.8 ± 28.6 μmol O{sub 2} min{sup -1} 100 g{sup -1}, P = 0.879). Hematocrit negatively correlated with CBF (r = -0.640, P < 0.001) and OEF (r = -0.701, P < 0.001), but not with CMRO{sub 2}. Altered neuropsychological test scores of ESRD patients were associated with OEF and CBF, but not with CMRO{sub 2}. There were weak relationships between eGFR and hematocrit (r = 0.308, P = 0.068) or CBF (r = 0.318, P = 0.059). Our findings suggested that anaemic young adults with ESRD may afford higher CBF and OEF to maintain a normal CMRO{sub 2}. Despite this compensatory process, however, cognitive function was still impaired and its severity was correlated with their CBF and OEF abnormality. (orig.)

  14. Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma

    Directory of Open Access Journals (Sweden)

    Nickel Michael

    2009-09-01

    Full Text Available Abstract Background Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. Results We investigated the budding process in Tethya wilhelma (Demospongiae by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-μCT image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Conclusion Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM.

  15. Oxidative Stress Promotes Asexual Reproduction and Apogamy in the Red Seaweed Pyropia yezoensis.

    Science.gov (United States)

    Takahashi, Megumu; Mikami, Koji

    2017-01-01

    The marine red seaweed Pyropia yezoensis has a haploid-diploid life cycle wherein two heteromorphic generations, a haploid gametophyte and a diploid sporophyte, are reciprocally generated from conchospores and carpospores, respectively. When we treated gametophytic blades of P. yezoensis with H2O2, discharge of asexual monospores was accelerated, resulting in increased numbers of gametophytic clones. Production of sporophytes without fertilization of male and female gametes was also observed. These findings indicate that oxidative stress can induce vegetative cells to develop into monospores that produce gametophytes asexually and can sometimes prompt carpospores to develop into sporophytes. The discovery of oxidative stress-triggered asexual reproduction and -apogamy will stimulate progress in studies of life-cycle regulation in P. yezoensis.

  16. [Morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates].

    Science.gov (United States)

    Isaeva, V V; Akhmadieva, A V; Aleksandriova, Ia N; Shukaliuk, A I

    2009-01-01

    Published and original data indicating evolutionary conservation of the morphofunctional organization of reserve stem cells providing for asexual and sexual reproduction of invertebrates are reviewed. Stem cells were studied in representatives of five animal types: archeocytes in sponge Oscarella malakhovi (Porifera), large interstitial cells in colonial hydroid Obelia longissima (Cnidaria), neoblasts in an asexual race of planarian Girardia tigrina (Platyhelmintes), stem cells in colonial rhizocephalans Peltogasterella gracilis, Polyascus polygenea, and Thylacoplethus isaevae (Arthropoda), and colonial ascidian Botryllus tuberatus (Chordata). Stem cells in animals of such diverse taxa feature the presence of germinal granules, are positive for proliferating cell nuclear antigen, demonstrate alkaline phosphatase activity (at marker of embryonic stem cells and primary germ cells in vertebrates), and rhizocephalan stem cells express the vasa-like gene (such genes are expressed in germline cells of different metazoans). The self-renewing pool of stem cells is the cellular basis of the reproductive strategy including sexual and asexual reproduction.

  17. The Key Role of Epigenetics in the Persistence of Asexual Lineages

    Directory of Open Access Journals (Sweden)

    Emilie Castonguay

    2012-01-01

    Full Text Available Asexual organisms, often perceived as evolutionary dead ends, can be long-lived and geographically widespread. We propose that epigenetic mechanisms could play a crucial role in the evolutionary persistence of these lineages. Genetically identical organisms could rely on phenotypic plasticity to face environmental variation. Epigenetic modifications could be the molecular mechanism enabling such phenotypic plasticity; they can be influenced by the environment and act at shorter timescales than mutation. Recent work on the asexual vertebrate Chrosomus eos-neogaeus (Pisces: Cyprinidae provides broad insights into the contribution of epigenetics in genetically identical individuals. We discuss the extension of these results to other asexual organisms, in particular those resulting from interspecific hybridizations. We finally develop on the evolutionary relevance of epigenetic variation in the context of heritability.

  18. Different Responses of Sexual and Asexual Reproduction of Arundinella hirta to Flooding

    Institute of Scientific and Technical Information of China (English)

    Zeng Bo; Fu Tianfei; Ulrich Schurr; Arnd J.Kuhn

    2006-01-01

    The sexual and asexual reproductive features of the graminoid species Arundinella hirta growing at riversides of the Jialing River were analyzed.It was found that the total seed mass,seed number per plant,and sexual reproductive allocation of A.hirta decreased with decreasing bank elevation,and plants growing at the lowest elevations of banks subjected to intense flooding did not show sexual reproduction.The total plant biomass and the number of ramifications per plant increased with flooding intensity,which implies that,contrary to sexual reproduction,asexual reproduction of A.hirta was enhanced by flooding.

  19. Genetic tests of ancient asexuality in Root Knot Nematodes reveal recent hybrid origins

    Directory of Open Access Journals (Sweden)

    Lunt David H

    2008-07-01

    Full Text Available Abstract Background The existence of "ancient asexuals", taxa that have persisted for long periods of evolutionary history without sexual recombination, is both controversial and important for our understanding of the evolution and maintenance of sexual reproduction. A lack of sex has consequences not only for the ecology of the asexual organism but also for its genome. Several genetic signatures are predicted from long-term asexual (apomictic reproduction including (i large "allelic" sequence divergence (ii lack of phylogenetic clustering of "alleles" within morphological species and (iii decay and loss of genes specific to meiosis and sexual reproduction. These genetic signatures can be hard to assess since it is difficult to demonstrate the allelic nature of very divergent sequences, divergence levels may be complicated by processes such as inter-specific hybridization, and genes may have secondary roles unrelated to sexual reproduction. Apomictic species of Meloidogyne root knot nematodes have been suggested previously to be ancient asexuals. Their relatives reproduce by meiotic parthenogenesis or facultative sexuality, which in combination with the abundance of nematode genomic sequence data, makes them a powerful system in which to study the consequences of reproductive mode on genomic divergence. Results Here, sequences from nuclear protein-coding genes are used to demonstrate that the first two predictions of ancient asexuality are found within the apomictic root knot nematodes. Alleles are more divergent in the apomictic taxa than in those species exhibiting recombination and do not group phylogenetically according to recognized species. In contrast some nuclear alleles, and mtDNA, are almost identical across species. Sequencing of Major Sperm Protein, a gamete-specific gene, from both meiotic and ameiotic species reveals no increase in evolutionary rate nor change in substitution pattern in the apomictic taxa, indicating that the locus

  20. "And Now I'm Just Different, but There's Nothing Actually Wrong With Me": Asexual Marginalization and Resistance.

    Science.gov (United States)

    Gupta, Kristina

    2016-09-15

    This article explores the relationship between contemporary asexual lives and compulsory sexuality, or the privileging of sexuality and the marginalizing of nonsexuality. Drawing on 30 in-depth interviews, I identify four ways the asexually identified individuals in this study saw themselves as affected by compulsory sexuality: pathologization, isolation, unwanted sex and relationship conflict, and the denial of epistemic authority. I also identify five ways these asexually identified individuals disrupted compulsory sexuality: adopting a language of difference and a capacity to describe asexuality; deemphasizing the importance of sexuality in human life; developing new types of nonsexual relationships; constituting asexuality as a sexual orientation or identity; and engaging in community building and outreach. I argue that some of these practices offer only a limited disruption of compulsory sexuality, but some of these practices pose a radical challenge to sexual norms by calling into question the widespread assumption that sexuality is a necessary part of human flourishing.

  1. Frequent detection of CXCR4-using viruses among Brazilian blood donors with HIV-1 long-standing infection and unknown clinical stage: Analysis of massive parallel sequencing data

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    Rodrigo Pessôa

    2016-03-01

    Full Text Available The determination of viral tropism is critically important and highly recommended to guide therapy with the CCR5 antagonist, which does not inhibit the effect of X4-tropic viruses. Here, we report the prevalence of HIV-1×4 HIV strains in 84 proviral DNA massively parallel sequencing “MPS” data from well-defined non-recently infected first-time Brazilian blood donors. The MPS data covering the entire V3 region of the env gene was extracted from our recently generated HIV-1 genomes sequenced by a paired-end protocol (Illumina. Of the 84 MPS data samples, 63 (75% were derived from donors with long-standing infection and 21 (25% were lacking stage information. HIV‐1 tropism was inferred using Geno2pheno (g2p [454] algorithm (FPR=1%, 2.5%, and 3.75%. Among the 84 data samples for which tropism was defined by g2p2.5%, 13 (15.5% participants had detectable CXCR4-using viruses in their MPS reads. Mixed infections with R5 and X4 were observed in 11.9% of the study subjects and minority X4 viruses were detected in 7 (8.3% of participants. Nine of the 63 (14.3% subjects with LS infection were predicted by g2p 2.5% to harbor proviral CXCR4-using viruses. Our findings of a high proportion of blood donors (15.5% harboring CXCR4-using viruses in PBMCs may indicate that this phenomenon is common. These findings may have implications for clinical and therapeutic aspects and may benefit individuals who plan to receive CCR5 antagonists.

  2. Laser Doppler flowmeter study on regional cerebral blood flow in early stage after standard superficial temporal artery-middle cerebral artery bypass surgery for moyamoya disease

    Institute of Scientific and Technical Information of China (English)

    GESANG Dun-zhu; ZHANG Dong; ZHAO Ji-zong; WANG Shuo; ZHAO Yuan-li; WANG Rong; SUN Jian-jun; MENG Ze

    2009-01-01

    Background Standard superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery is an effective treatment for moyamoya disease, but recent evidence suggests that postoperative cerebral hyperperfusion can occur. In this study, the trendline of changes in regional cerebral blood flow (rCBF) after surgery were continually monitored near the site of anastomosis in order to investigate both the efficacy of the procedure for improving rCBF and the possible riskof hyperperfusion.Methods Standard STA-MCA bypass surgery was performed on 13 patients, rCBF was measured continually using laser Doppler flowmetry (LDF) until the 5th day after the operation with the LDF probe implanted adjacent to the area of the anastomosis. The trendline of rCBF changes postoperatively was recorded for the analysis performed using SPSS 13.0.Results The baseline LDF value of cortical rCBF was (84.68±14.39) perfusion unit (PU), which was linear relative to absolute perfusion volume before anastomosis and (88.90±11.26) PU immediately after anastomosis (P >0.05). The value changed significantly from before to after anastomosis (P 0.05).Conclusions STA-MCA anastomosis improves the cerebral blood supply significantly in the early stage after surgery,however, the risk of symptomatic hyperperfusion may exist, which may possibly occur on the 1st day and 5th day after surgery. A LDF is useful for postoperative monitoring for both the efficacy of bypass and possible risk of neurologic deterioration or bleeding from hyperperfusion.

  3. Assessment of humoral immune responses to blood-stage malaria antigens following ChAd63-MVA immunization, controlled human malaria infection and natural exposure.

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    Sumi Biswas

    Full Text Available The development of protective vaccines against many difficult infectious pathogens will necessitate the induction of effective antibody responses. Here we assess humoral immune responses against two antigens from the blood-stage merozoite of the Plasmodium falciparum human malaria parasite--MSP1 and AMA1. These antigens were delivered to healthy malaria-naïve adult volunteers in Phase Ia clinical trials using recombinant replication-deficient viral vectors--ChAd63 to prime the immune response and MVA to boost. In subsequent Phase IIa clinical trials, immunized volunteers underwent controlled human malaria infection (CHMI with P. falciparum to assess vaccine efficacy, whereby all but one volunteer developed low-density blood-stage parasitemia. Here we assess serum antibody responses against both the MSP1 and AMA1 antigens following i ChAd63-MVA immunization, ii immunization and CHMI, and iii primary malaria exposure in the context of CHMI in unimmunized control volunteers. Responses were also assessed in a cohort of naturally-immune Kenyan adults to provide comparison with those induced by a lifetime of natural malaria exposure. Serum antibody responses against MSP1 and AMA1 were characterized in terms of i total IgG responses before and after CHMI, ii responses to allelic variants of MSP1 and AMA1, iii functional growth inhibitory activity (GIA, iv IgG avidity, and v isotype responses (IgG1-4, IgA and IgM. These data provide the first in-depth assessment of the quality of adenovirus-MVA vaccine-induced antibody responses in humans, along with assessment of how these responses are modulated by subsequent low-density parasite exposure. Notable differences were observed in qualitative aspects of the human antibody responses against these malaria antigens depending on the means of their induction and/or exposure of the host to the malaria parasite. Given the continued clinical development of viral vectored vaccines for malaria and a range of other

  4. Phase 1 trial of the Plasmodium falciparum blood stage vaccine MSP1(42-C1/Alhydrogel with and without CPG 7909 in malaria naive adults.

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    Ruth D Ellis

    Full Text Available BACKGROUND: Merozoite surface protein 1(42 (MSP1(42 is a leading blood stage malaria vaccine candidate. In order to induce immune responses that cover the major antigenic polymorphisms, FVO and 3D7 recombinant proteins of MSP1(42 were mixed (MSP1(42-C1. To improve the level of antibody response, MSP1(42-C1 was formulated with Alhydrogel plus the novel adjuvant CPG 7909. METHODS: A Phase 1 clinical trial was conducted in healthy malaria-naïve adults at the Center for Immunization Research in Washington, D.C., to evaluate the safety and immunogenicity of MSP1(42-C1/Alhydrogel +/- CPG 7909. Sixty volunteers were enrolled in dose escalating cohorts and randomized to receive three vaccinations of either 40 or 160 microg protein adsorbed to Alhydrogel +/- 560 microg CPG 7909 at 0, 1 and 2 months. RESULTS: Vaccinations were well tolerated, with only one related adverse event graded as severe (Grade 3 injection site erythema and all other vaccine related adverse events graded as either mild or moderate. Local adverse events were more frequent and severe in the groups receiving CPG. The addition of CPG enhanced anti-MSP1(42 antibody responses following vaccination by up to 49-fold two weeks after second immunization and 8-fold two weeks after the third immunization when compared to MSP1(42-C1/Alhydrogel alone (p<0.0001. After the third immunization, functionality of the antibody was tested by an in vitro growth inhibition assay. Inhibition was a function of antibody titer, with an average of 3% (range -2 to 10% in the non CPG groups versus 14% (3 to 32% in the CPG groups. CONCLUSION/SIGNIFICANCE: The favorable safety profile and high antibody responses induced with MSP1(42-C1/Alhydrogel + CPG 7909 are encouraging. MSP1(42-C1/Alhydrogel is being combined with other blood stage antigens and will be taken forward in a formulation adjuvanted with CPG 7909. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00320658.

  5. Iyengar Yoga versus Enhanced Usual Care on Blood Pressure in Patients with Prehypertension to Stage I Hypertension: a Randomized Controlled Trial

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    Debbie L. Cohen

    2011-01-01

    Full Text Available The prevalence of prehypertension and Stage 1 hypertension continues to increase despite being amenable to non-pharmacologic interventions. Iyengar yoga (IY has been purported to reduce blood pressure (BP though evidence from randomized trials is lacking. We conducted a randomized controlled trial to assess the effects of 12 weeks of IY versus enhanced usual care (EUC (based on individual dietary adjustment on 24-h ambulatory BP in yoga-naïve adults with untreated prehypertension or Stage 1 hypertension. In total, 26 and 31 subjects in the IY and EUC arms, respectively, completed the study. There were no differences in BP between the groups at 6 and 12 weeks. In the EUC group, 24-h systolic BP (SBP, diastolic BP (DBP and mean arterial pressure (MAP significantly decreased by 5, 3 and 3 mmHg, respectively, from baseline at 6 weeks (P < .05, but were no longer significant at 12 weeks. In the IY group, 24 h SBP was reduced by 6 mmHg at 12 weeks compared to baseline (P = .05. 24 h DBP (P < .01 and MAP (P < .05 decreased significantly each by 5 mmHg. No differences were observed in catecholamine or cortisol metabolism to explain the decrease in BP in the IY group at 12 weeks. Twelve weeks of IY produces clinically meaningful improvements in 24 h SBP and DBP. Larger studies are needed to establish the long term efficacy, acceptability, utility and potential mechanisms of IY to control BP.

  6. Vegetative Compatibility and Asexual Recombination in Magnaporthe grisea from Jiangsu Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-li; ZHANG Zheng-guang; ZHENG Xiao-bo

    2003-01-01

    Vegetative compatibility among isolates of different races in Magnaporthe grisea collectedfrom Jiangsu Province and asexual recombination among compatible isolates by anastomosis were tested.Twenty isolates involving seven races from diseased rice plants were paired on polished rice rose bengal mediumand incubated at 25℃ in darkness for 18 days. Among 173 pairings tested, solid hyphai fusion lines formed byanastomosis between 124 pairings, indicated that these isolates were vegetative compatible with each other.The result showed that most M. grisea isolates were vegetative compatible. Furthermore, 17 vegetative com-patible pairings between monoconidial isolates with MBCsIPTr marker and isolates with MBCrIPTs markerwere selected to detect the asexual recombination between the compatible isolates of different races. The asexu-al recombinants with MBCrIPTr marker were detected in single hyphal fragment progenies in thirteen of theseventeen pairings. The percentage of recombinants was about 0.6 - 11.3%. Results showed that vegetative com-patibility was prevailing among isolates of M. grisea in Jiangsu Province in vitro. These results also suggested thatasexual recombination may be an important mechanism for M. grisea to maintain genetic diversity in nature.

  7. Detection of Gene Flow from Sexual to Asexual Lineages in Thrips tabaci (Thysanoptera: Thripidae).

    Science.gov (United States)

    Li, Xiao-Wei; Wang, Ping; Fail, Jozsef; Shelton, Anthony M

    2015-01-01

    Populations of Thrips tabaci are known to have two sympatric but genetically isolated reproductive modes, arrhenotoky (sexual reproduction) and thelytoky (asexual reproduction). Herein, we report behavioral, ecological and genetic studies to determine whether there is gene flow between arrhenotokous and thelytokous T. tabaci. We did not detect significant preference by arrhenotokous males to mate with females of a particular reproductive mode, nor did we detect significant behavioral differences between arrhenotokous males mated with arrhenotokous or thelytokous females in their pre-copulation, copulation duration and mating frequency. Productive gene transfer resulting from the mating between the two modes was experimentally confirmed. Gene transfer from arrhenotokous T. tabaci to thelytokous T. tabaci was further validated by confirmation of the passage of the arrhenotokous male-originated nuclear gene (histone H3 gene) allele to the F2 generation. These behavioral, ecological and genetic studies confirmed gene transfer from the sexual arrhenotokous mode to the asexual thelytokous mode of T. tabaci in the laboratory. These results demonstrate that asexual T. tabaci populations may acquire genetic variability from sexual populations, which could offset the long-term disadvantage of asexual reproduction.

  8. Characterization of oxylipins and dioxygenase genes in the asexual fungus Aspergillus niger

    NARCIS (Netherlands)

    Wadman, Mayken W; de Vries, Ronald P; Kalkhove, Stefanie I C; Veldink, Gerrit A; Vliegenthart, Johannes F G

    2009-01-01

    BACKGROUND: Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction 1. An example of such genes are the dio

  9. Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides

    Science.gov (United States)

    The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plant...

  10. Sexual vs. asexual reproduction in an ecosystem engineer: the massive coral Montastraea annularis.

    Science.gov (United States)

    Foster, Nicola L; Baums, Iliana B; Mumby, Peter J

    2007-03-01

    1. Long-lived sedentary organisms with a massive morphology are often assumed to utilize a storage effect whereby the persistence of a small group of adults can maintain the population when sexual recruitment fails. However, employing storage effects could prove catastrophic if, under changing climatic conditions, the time period between favourable conditions becomes so prolonged that the population cannot be sustained solely be sexual recruitment. When a species has multiple reproductive options, a rapidly changing environment may favour alternative asexual means of propagation. 2. Here, we revisit the importance of asexual dispersal in a massive coral subject to severe climate-induced disturbance. Montastraea annularis is a major framework-builder of Caribbean coral reefs but its survival is threatened by the increasing cover of macroalgae that prevents settlement of coral larvae. 3. To estimate levels of asexual recruitment within populations of M. annularis, samples from three sites in Honduras were genotyped using four, polymorphic microsatellite loci. 4. A total of 114 unique genets were identified with 8% consisting of two or more colonies and an exceptionally large genet at the third site comprising 14 colonies. 5. At least 70% of multicolony genets observed were formed by physical breakage, consistent with storm damage. 6. Our results reveal that long-lived massive corals can propagate using asexual methods even though sexual strategies predominate.

  11. Detection of Gene Flow from Sexual to Asexual Lineages in Thrips tabaci (Thysanoptera: Thripidae.

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Li

    Full Text Available Populations of Thrips tabaci are known to have two sympatric but genetically isolated reproductive modes, arrhenotoky (sexual reproduction and thelytoky (asexual reproduction. Herein, we report behavioral, ecological and genetic studies to determine whether there is gene flow between arrhenotokous and thelytokous T. tabaci. We did not detect significant preference by arrhenotokous males to mate with females of a particular reproductive mode, nor did we detect significant behavioral differences between arrhenotokous males mated with arrhenotokous or thelytokous females in their pre-copulation, copulation duration and mating frequency. Productive gene transfer resulting from the mating between the two modes was experimentally confirmed. Gene transfer from arrhenotokous T. tabaci to thelytokous T. tabaci was further validated by confirmation of the passage of the arrhenotokous male-originated nuclear gene (histone H3 gene allele to the F2 generation. These behavioral, ecological and genetic studies confirmed gene transfer from the sexual arrhenotokous mode to the asexual thelytokous mode of T. tabaci in the laboratory. These results demonstrate that asexual T. tabaci populations may acquire genetic variability from sexual populations, which could offset the long-term disadvantage of asexual reproduction.

  12. Extensive chromosomal reshuffling drives evolution of virulence in an asexual pathogen

    Science.gov (United States)

    Pathogen populations that undergo regular sexual reproduction are thought to pose a greater risk to plant breeders than pathogens limited to asexual reproduction because they can recombine alleles that contribute to virulence in the face of dynamic environmental conditions. Despite this, many devas...

  13. Evolution of the asexual queen succession system and its underlying mechanisms in termites.

    Science.gov (United States)

    Matsuura, Kenji

    2017-01-01

    One major advantage of sexual reproduction over asexual reproduction is its promotion of genetic variation, although it reduces the genetic contribution to offspring. Queens of social insects double their contribution to the gene pool, while overuse of asexual reproduction may reduce the ability of the colony to adapt to environmental stress because of the loss of genetic diversity. Recent studies have revealed that queens of some termite species can solve this tradeoff by using parthenogenesis to produce the next generation of queens and sexual reproduction to produce other colony members. This reproductive system, known as asexual queen succession (AQS), has been identified in the subterranean termites Reticulitermes speratus, Reticulitermes virginicus and Reticulitermes lucifugus and in the Neotropical higher termites Embiratermes neotenicus and Cavitermes tuberosus The studies presented here have uncovered the unusual modes of reproduction in termites and have aimed to identify their underlying mechanisms. The study of AQS, the mixed use of sexual and asexual reproduction, is of fundamental importance as it may provide a key to solve the evolutionary paradox of sex.

  14. Asexual reproduction in a close relative of Arabidopsis: a genetic investigation of apomixis in Boechera ( Brassicaceae).

    NARCIS (Netherlands)

    Schranz, M.E.; Kantama, L.; Jong, de J.H.S.G.M.; Mitchell-Olds, T.

    2006-01-01

    Understanding apomixis (asexual reproduction through seeds) is of great interest to both plant breeders and evolutionary biologists. The genus Boechera is an excellent system for studying apomixis because of its close relationship to Arabidopsis, the occurrence of apomixis at the diploid level, and

  15. In vivo approaches reveal a key role for DCs in CD4+ T cell activation and parasite clearance during the acute phase of experimental blood-stage malaria.

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    Henrique Borges da Silva

    2015-02-01

    Full Text Available Dendritic cells (DCs are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip, with Plasmodium chabaudi AS (Pc parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection.

  16. In Vivo Approaches Reveal a Key Role for DCs in CD4+ T Cell Activation and Parasite Clearance during the Acute Phase of Experimental Blood-Stage Malaria

    Science.gov (United States)

    Borges da Silva, Henrique; Fonseca, Raíssa; Cassado, Alexandra dos Anjos; Machado de Salles, Érika; de Menezes, Maria Nogueira; Langhorne, Jean; Perez, Katia Regina; Cuccovia, Iolanda Midea; Ryffel, Bernhard; Barreto, Vasco M.; Marinho, Cláudio Romero Farias; Boscardin, Silvia Beatriz; Álvarez, José Maria; D’Império-Lima, Maria Regina; Tadokoro, Carlos Eduardo

    2015-01-01

    Dendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin)-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip), with Plasmodium chabaudi AS (Pc) parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs) by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection. PMID:25658925

  17. Do clones degenerate over time? Explaining the genetic variability of asexuals through population genetic models

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    Drozd Pavel

    2011-03-01

    Full Text Available Abstract Background Quest for understanding the nature of mechanisms governing the life span of clonal organisms lasts for several decades. Phylogenetic evidence for recent origins of most clones is usually interpreted as proof that clones suffer from gradual age-dependent fitness decay (e.g. Muller's ratchet. However, we have shown that a neutral drift can also qualitatively explain the observed distribution of clonal ages. This finding was followed by several attempts to distinguish the effects of neutral and non-neutral processes. Most recently, Neiman et al. 2009 (Ann N Y Acad Sci.:1168:185-200. reviewed the distribution of asexual lineage ages estimated from a diverse array of taxa and concluded that neutral processes alone may not explain the observed data. Moreover, the authors inferred that similar types of mechanisms determine maximum asexual lineage ages in all asexual taxa. In this paper we review recent methods for distinguishing the effects of neutral and non-neutral processes and point at methodological problems related with them. Results and Discussion We found that contemporary analyses based on phylogenetic data are inadequate to provide any clear-cut answer about the nature and generality of processes affecting evolution of clones. As an alternative approach, we demonstrate that sequence variability in asexual populations is suitable to detect age-dependent selection against clonal lineages. We found that asexual taxa with relatively old clonal lineages are characterised by progressively stronger deviations from neutrality. Conclusions Our results demonstrate that some type of age-dependent selection against clones is generally operational in asexual animals, which cover a wide taxonomic range spanning from flatworms to vertebrates. However, we also found a notable difference between the data distribution predicted by available models of sequence evolution and those observed in empirical data. These findings point at the

  18. Plasmodium vivax merozoite surface protein-3 (PvMSP3: expression of an 11 member multigene family in blood-stage parasites.

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    Jianlin Jiang

    Full Text Available BACKGROUND: Three members of the Plasmodium vivax merozoite surface protein-3 (PvMSP3 family (PvMSP3-α, PvMSP3-β and PvMSP3-γ were initially characterized and later shown to be part of a larger highly diverse family, encoded by a cluster of genes arranged head-to-tail in chromosome 10. PvMSP3-α and PvMSP3-β have become genetic markers in epidemiological studies, and are being evaluated as vaccine candidates. This research investigates the gene and protein expression of the entire family and pertinent implications. METHODOLOGY/PRINCIPAL FINDINGS: A 60 kb multigene locus from chromosome 10 in P. vivax (Salvador 1 strain was studied to classify the number of pvmsp3 genes present, and compare their transcription, translation and protein localization patterns during blood-stage development. Eleven pvmsp3 paralogs encode an N-terminal NLRNG signature motif, a central domain containing repeated variable heptad sequences, and conserved hydrophilic C-terminal features. One additional ORF in the locus lacks these features and was excluded as a member of the family. Transcripts representing all eleven pvmsp3 genes were detected in trophozoite- and schizont-stage RNA. Quantitative immunoblots using schizont-stage extracts and antibodies specific for each PvMSP3 protein demonstrated that all but PvMSP3.11 could be detected. Homologs were also detected by immunoblot in the closely related simian species, P. cynomolgi and P. knowlesi. Immunofluorescence assays confirmed that eight of the PvMSP3s are present in mature schizonts. Uniquely, PvMSP3.7 was expressed exclusively at the apical end of merozoites. CONCLUSION/SIGNIFICANCE: Specific proteins were detected representing the expression of 10 out of 11 genes confirmed as members of the pvmsp3 family. Eight PvMSP3s were visualized surrounding merozoites. In contrast, PvMSP3.7 was detected at the apical end of the merozoites. Pvmsp3.11 transcripts were present, though no corresponding protein was detected

  19. Effect of the pre-erythrocytic candidate malaria vaccine RTS,S/AS01E on blood stage immunity in young children

    DEFF Research Database (Denmark)

    Bejon, Philip; Cook, Jackie; Bergmann-Leitner, Elke

    2011-01-01

    -linked immunosorbent assay, antibodies to 4 Plasmodium falciparum merozoite antigens (AMA-1, MSP-1(42), EBA-175, and MSP-3) and by growth inhibitory activity (GIA) using 2 parasite clones (FV0 and 3D7) at 4 times on 860 children who were randomized to receive with RTS,S/AS01(E) or a control vaccine. Results. Antibody......(See the article by Greenhouse et al, on pages 19-26.) Background. RTS,S/AS01(E) is the lead candidate malaria vaccine and confers pre-erythrocytic immunity. Vaccination may therefore impact acquired immunity to blood-stage malaria parasites after natural infection. Methods. We measured, by enzyme...... concentrations to AMA-1, EBA-175, and MSP-1(42) decreased with age during the first year of life, then increased to 32 months of age. Anti-MSP-3 antibody concentrations gradually increased, and GIA gradually decreased up to 32 months. Vaccination with RTS,S/AS01(E) resulted in modest reductions in AMA-1, EBA-175...

  20. Combining viral vectored and protein-in-adjuvant vaccines against the blood-stage malaria antigen AMA1: report on a phase 1a clinical trial.

    Science.gov (United States)

    Hodgson, Susanne H; Choudhary, Prateek; Elias, Sean C; Milne, Kathryn H; Rampling, Thomas W; Biswas, Sumi; Poulton, Ian D; Miura, Kazutoyo; Douglas, Alexander D; Alanine, Daniel Gw; Illingworth, Joseph J; de Cassan, Simone C; Zhu, Daming; Nicosia, Alfredo; Long, Carole A; Moyle, Sarah; Berrie, Eleanor; Lawrie, Alison M; Wu, Yimin; Ellis, Ruth D; Hill, Adrian V S; Draper, Simon J

    2014-12-01

    The development of effective vaccines against difficult disease targets will require the identification of new subunit vaccination strategies that can induce and maintain effective immune responses in humans. Here we report on a phase 1a clinical trial using the AMA1 antigen from the blood-stage Plasmodium falciparum malaria parasite delivered either as recombinant protein formulated with Alhydrogel adjuvant with and without CPG 7909, or using recombinant vectored vaccines--chimpanzee adenovirus ChAd63 and the orthopoxvirus MVA. A variety of promising "mixed-modality" regimens were tested. All volunteers were primed with ChAd63, and then subsequently boosted with MVA and/or protein-in-adjuvant using either an 8- or 16-week prime-boost interval. We report on the safety of these regimens, as well as the T cell, B cell, and serum antibody responses. Notably, IgG antibody responses primed by ChAd63 were comparably boosted by AMA1 protein vaccine, irrespective of whether CPG 7909 was included in the Alhydrogel adjuvant. The ability to improve the potency of a relatively weak aluminium-based adjuvant in humans, by previously priming with an adenoviral vaccine vector encoding the same antigen, thus offers a novel vaccination strategy for difficult or neglected disease targets when access to more potent adjuvants is not possible.

  1. Phase 1 study in malaria naive adults of BSAM2/Alhydrogel®+CPG 7909, a blood stage vaccine against P. falciparum malaria.

    Directory of Open Access Journals (Sweden)

    Ruth D Ellis

    Full Text Available A Phase 1 dose escalating study was conducted in malaria naïve adults to assess the safety, reactogenicity, and immunogenicity of the blood stage malaria vaccine BSAM2/Alhydrogel®+ CPG 7909. BSAM2 is a combination of the FVO and 3D7 alleles of recombinant AMA1 and MSP1(42, with equal amounts by weight of each of the four proteins mixed, bound to Alhydrogel®, and administered with the adjuvant CPG 7909. Thirty (30 volunteers were enrolled in two dose groups, with 15 volunteers receiving up to three doses of 40 µg total protein at Days 0, 56, and 180, and 15 volunteers receiving up to three doses of 160 µg protein on the same schedule. Most related adverse events were mild or moderate, but 4 volunteers experienced severe systemic reactions and two were withdrawn from vaccinations due to adverse events. Geometric mean antibody levels after two vaccinations with the high dose formulation were 136 µg/ml for AMA1 and 78 µg/ml for MSP1(42. Antibody responses were not significantly different in the high dose versus low dose groups and did not further increase after third vaccination. In vitro growth inhibition was demonstrated and was closely correlated with anti-AMA1 antibody responses. A Phase 1b trial in malaria-exposed adults is being conducted.Clinicaltrials.gov NCT00889616.

  2. Early stage carcinoma of the uterine cervix. Effects of intracavitary radium treatment on lymphoid cells in blood and pelvic lymph nodes

    Energy Technology Data Exchange (ETDEWEB)

    Onsrud, M.; Grahm, I.; Gaudernack, G.

    Sixteen patients with early stage carcinoma of the uterine cervix treated with primary radical hysterectomy and pelvic lymphadenectomy were compared with 17 patients who four to six weeks before the operation received intracavitary treatment with radium. The calculated radiation dose to the pelvic wall was approximately 10 Gy. The distribution of lymphoid cells in blood and pelvic lymph nodes was studied by an indirect immunoflourescence technique using monoclonal antibodies. The radium treated group showed a significant reduction of circulating OKT4+ (T helper) and OKT8+ (T suppressor/cytotoxic) lymphocytes. The number of Leu7+ (natural killer) cells and 1D5+ cells (monocytes) was not changed, but the ratio between monocytes and T cells was increased after radium therapy. In cell suspensions obtained from the pelvic lymph nodes, the radium treatment induced a significant reduction of the OKT4+ cell fraction. It is concluded that this low dose rate regimen of intracavitary treatment induces changes in the immune system which are of the same type as those seen after external field irradiation.

  3. A PfRH5-Based Vaccine Is Efficacious against Heterologous Strain Blood-Stage Plasmodium falciparum Infection in Aotus Monkeys

    Science.gov (United States)

    Douglas, Alexander D.; Baldeviano, G. Christian; Lucas, Carmen M.; Lugo-Roman, Luis A.; Crosnier, Cécile; Bartholdson, S. Josefin; Diouf, Ababacar; Miura, Kazutoyo; Lambert, Lynn E.; Ventocilla, Julio A.; Leiva, Karina P.; Milne, Kathryn H.; Illingworth, Joseph J.; Spencer, Alexandra J.; Hjerrild, Kathryn A.; Alanine, Daniel G.W.; Turner, Alison V.; Moorhead, Jeromy T.; Edgel, Kimberly A.; Wu, Yimin; Long, Carole A.; Wright, Gavin J.; Lescano, Andrés G.; Draper, Simon J.

    2015-01-01

    Summary Antigenic diversity has posed a critical barrier to vaccine development against the pathogenic blood-stage infection of the human malaria parasite Plasmodium falciparum. To date, only strain-specific protection has been reported by trials of such vaccines in nonhuman primates. We recently showed that P. falciparum reticulocyte binding protein homolog 5 (PfRH5), a merozoite adhesin required for erythrocyte invasion, is highly susceptible to vaccine-inducible strain-transcending parasite-neutralizing antibody. In vivo efficacy of PfRH5-based vaccines has not previously been evaluated. Here, we demonstrate that PfRH5-based vaccines can protect Aotus monkeys against a virulent vaccine-heterologous P. falciparum challenge and show that such protection can be achieved by a human-compatible vaccine formulation. Protection was associated with anti-PfRH5 antibody concentration and in vitro parasite-neutralizing activity, supporting the use of this in vitro assay to predict the in vivo efficacy of future vaccine candidates. These data suggest that PfRH5-based vaccines have potential to achieve strain-transcending efficacy in humans. PMID:25590760

  4. Coalescence with Background and Balancing Selection in Systems with Bi- and Uniparental Reproduction: Contrasting Partial Asexuality and Selfing.

    Science.gov (United States)

    Agrawal, Aneil F; Hartfield, Matthew

    2016-01-01

    Uniparental reproduction in diploids, via asexual reproduction or selfing, reduces the independence with which separate loci are transmitted across generations. This is expected to increase the extent to which a neutral marker is affected by selection elsewhere in the genome. Such effects have previously been quantified in coalescent models involving selfing. Here we examine the effects of background selection and balancing selection in diploids capable of both sexual and asexual reproduction (i.e., partial asexuality). We find that the effect of background selection on reducing coalescent time (and effective population size) can be orders of magnitude greater when rates of sex are low than when sex is common. This is because asexuality enhances the effects of background selection through both a recombination effect and a segregation effect. We show that there are several reasons that the strength of background selection differs between systems with partial asexuality and those with comparable levels of uniparental reproduction via selfing. Expectations for reductions in Ne via background selection have been verified using stochastic simulations. In contrast to background selection, balancing selection increases the coalescence time for a linked neutral site. With partial asexuality, the effect of balancing selection is somewhat dependent upon the mode of selection (e.g., heterozygote advantage vs. negative frequency-dependent selection) in a manner that does not apply to selfing. This is because the frequency of heterozygotes, which are required for recombination onto alternative genetic backgrounds, is more dependent on the pattern of selection with partial asexuality than with selfing.

  5. The maintenance of sex, clonal dynamics, and host-parasite coevolution in a mixed population of sexual and asexual snails.

    Science.gov (United States)

    Jokela, Jukka; Dybdahl, Mark F; Lively, Curtis M

    2009-07-01

    Sexual populations should be vulnerable to invasion and replacement by ecologically similar asexual females because asexual lineages have higher per capita growth rates. However, as asexual genotypes become common, they may also become disproportionately infected by parasites. The Red Queen hypothesis postulates that high infection rates in the common asexual clones could periodically favor the genetically diverse sexual individuals and promote the short-term coexistence of sexual and asexual populations. Testing this idea requires comparison of competing sexual and asexual lineages that are attacked by natural parasites. To date no such data have been available. Here, we report on long-term dynamics and parasite coevolution in a "mixed" (sexual and asexual) population of snails (Potamopyrgus antipodarum). We found that, within 7-10 years, the most common clones were almost completely replaced by initially rare clones in two different habitats, while sexuals persisted throughout the study period. The common clones, which were initially more resistant to infection, also became more susceptible to infection by sympatric (but not allopatric) parasites over the course of the study. These results are consistent with the Red Queen hypothesis and show that the coevolutionary dynamics predicted by the theory may also favor sexual reproduction in natural populations.

  6. Persistent Copulation in Asexual Female   Potamopyrgus antipodarum: Evidence for Male Control with Size-Based Preferences

    Directory of Open Access Journals (Sweden)

    Amanda E. Nelson

    2011-01-01

    Full Text Available Transitions from sexual to asexual reproduction provide a useful context for investigating the evolutionary loss of nonfunctional traits. It is often assumed that useless behaviors or structures will degrade, but this process is poorly understood. Potamopyrgus antipodarum is an ancestrally sexual New Zealand freshwater snail characterized by numerous independent transitions to asexual all-female lineages. The availability of multiple independently-derived asexual lineages of various time since derivation from sexual ancestors means that the P. antipodarum system is well-suited for the study of trait loss related to mating behavior and copulation. Here, we asked whether mating behavior in asexual female P. antipodarum degrades with increasing asexual lineage age. While copulation frequency did not differ in females from old versus young asexual lineages, post hoc analyses indicated that it was instead positively associated with mean lineage female size. We observed that female P. antipodarum take a passive physical role in copulatory interactions, indicating that female behavior may not be a useful variable for detection of sex-related vestigialization in this system. Instead, males seem to be in proximate control of copulation frequencies, meaning that male mating behavior may be a primary determinant of the expression of mating behavior in asexual female P. antipodarum.

  7. Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, asexual fungus-growing ant.

    Science.gov (United States)

    Rabeling, Christian; Gonzales, Omar; Schultz, Ted R; Bacci, Maurício; Garcia, Marcos V B; Verhaagh, Manfred; Ishak, Heather D; Mueller, Ulrich G

    2011-07-26

    Sex and recombination are central processes in life generating genetic diversity. Organisms that rely on asexual propagation risk extinction due to the loss of genetic diversity and the inability to adapt to changing environmental conditions. The fungus-growing ant species Mycocepurus smithii was thought to be obligately asexual because only parthenogenetic populations have been collected from widely separated geographic localities. Nonetheless, M. smithii is ecologically successful, with the most extensive distribution and the highest population densities of any fungus-growing ant. Here we report that M. smithii actually consists of a mosaic of asexual and sexual populations that are nonrandomly distributed geographically. The sexual populations cluster along the Rio Amazonas and the Rio Negro and appear to be the source of independently evolved and widely distributed asexual lineages, or clones. Either apomixis or automixis with central fusion and low recombination rates is inferred to be the cytogenetic mechanism underlying parthenogenesis in M. smithii. Males appear to be entirely absent from asexual populations, but their existence in sexual populations is indicated by the presence of sperm in the reproductive tracts of queens. A phylogenetic analysis of the genus suggests that M. smithii is monophyletic, rendering a hybrid origin of asexuality unlikely. Instead, a mitochondrial phylogeny of sexual and asexual populations suggests multiple independent origins of asexual reproduction, and a divergence-dating analysis indicates that M. smithii evolved 0.5-1.65 million years ago. Understanding the evolutionary origin and maintenance of asexual reproduction in this species contributes to a general understanding of the adaptive significance of sex.

  8. Study of Interference Treatment by Xuesaitong (血塞通) Soft Capsule on Patients of Nephrosis Syndrome with Qi Deficiency and Blood Stasis during Dose Reducing Stage of Corticosteroid

    Institute of Scientific and Technical Information of China (English)

    吕勇; 王亿平; 张莉

    2004-01-01

    Objective: To observe the effect of Xuesaitong (血塞通, XST) soft capsule in interference treatment on patients of nephrosis syndrome (NS) during corticosteroid (CS) dose reducing stage. Methods:Seventy-one NS patients applying prednisone and initiating dose reducing stage were randomized into trial group and control group. On the basis of conventional prednisone dose reduction of both groups, the trial group was given additionally XST, and the treatment course ended with the reduction to maintenance dose. In the course of observation, those who did not comply with the criteria of observation were excluded. Before and after the dose reduction, TCM syndrome scoring, 24 hrs urinary protein amount, blood β2-microglobulin (β2-MG), urinary β2-MG, blood fibrinogen (Fbg), plasma prothrombin time (PT), blood lipid, etc. were observed. Results: The trial group of XST could obviously lower their urinary protein amount and blood lipid level (P<0.05 or P<0.01), markedly improve the blood coagulation parameters (P<0.01), improve the TCM syndrome and CS induced adverse reaction (P<0.05 or P<0.01), also obviously reduced the recurrence rate of NS (P<0.05). Conclusion: XST could obviously improve the clinical symptoms and renal impairment parameters in NS patients during CS dose reduction stage, improve the CS induced adverse reaction and prevent the recurrence of NS.

  9. THE RHEOLOGICAL PROPERTIES OF BLOOD IN THE MOST ACUTE STAGE OF ISCHEMIC STROKE AND THEIR RELATION TO THE SEVERITY OF NEUROLOGICAL IMPAIRMENT

    Directory of Open Access Journals (Sweden)

    M. N. Azhermacheva

    2013-01-01

    Full Text Available The study evaluated the rheological parameters of blood: blood viscosity, plasma viscosity, hematocrit, red blood cell aggregation and deformability. The severity of the patients was assessed by clinical scales:Glasgowcoma scale, the scale NIHSS, Barthel index. The study found that in the acute phase of ischemic stroke increased blood viscosity by increasing red blood cell aggregation and reduced erythrocyte deformability. The increase in the viscosity of the blood in acute ischemic stroke is accompanied by increased severity of neurological disorders.

  10. Safety and Reproducibility of a Clinical Trial System Using Induced Blood Stage Plasmodium vivax Infection and Its Potential as a Model to Evaluate Malaria Transmission

    Science.gov (United States)

    Elliott, Suzanne; Sekuloski, Silvana; Sikulu, Maggy; Hugo, Leon; Khoury, David; Cromer, Deborah; Davenport, Miles; Sattabongkot, Jetsumon; Ivinson, Karen; Ockenhouse, Christian; McCarthy, James

    2016-01-01

    Background Interventions to interrupt transmission of malaria from humans to mosquitoes represent an appealing approach to assist malaria elimination. A limitation has been the lack of systems to test the efficacy of such interventions before proceeding to efficacy trials in the field. We have previously demonstrated the feasibility of induced blood stage malaria (IBSM) infection with Plasmodium vivax. In this study, we report further validation of the IBSM model, and its evaluation for assessment of transmission of P. vivax to Anopheles stephensi mosquitoes. Methods Six healthy subjects (three cohorts, n = 2 per cohort) were infected with P. vivax by inoculation with parasitized erythrocytes. Parasite growth was monitored by quantitative PCR, and gametocytemia by quantitative reverse transcriptase PCR (qRT-PCR) for the mRNA pvs25. Parasite multiplication rate (PMR) and size of inoculum were calculated by linear regression. Mosquito transmission studies were undertaken by direct and membrane feeding assays over 3 days prior to commencement of antimalarial treatment, and midguts of blood fed mosquitoes dissected and checked for presence of oocysts after 7–9 days. Results The clinical course and parasitemia were consistent across cohorts, with all subjects developing mild to moderate symptoms of malaria. No serious adverse events were reported. Asymptomatic elevated liver function tests were detected in four of six subjects; these resolved without treatment. Direct feeding of mosquitoes was well tolerated. The estimated PMR was 9.9 fold per cycle. Low prevalence of mosquito infection was observed (1.8%; n = 32/1801) from both direct (4.5%; n = 20/411) and membrane (0.9%; n = 12/1360) feeds. Conclusion The P. vivax IBSM model proved safe and reliable. The clinical course and PMR were reproducible when compared with the previous study using this model. The IBSM model presented in this report shows promise as a system to test transmission-blocking interventions

  11. Mating type sequences in asexually reproducing Fusarium species

    NARCIS (Netherlands)

    Kenényi, Z.; Moretti, A.; Waalwijk, C.; Oláh, B.; Hornok, L.

    2004-01-01

    To assess the potential for mating in several Fusarium species with no known sexual stage, we developed degenerate and semidegenerate oligonucleotide primers to identify conserved mating type (MAT) sequences in these fungi. The putative and high-mobility-group (HMG) box sequences from Fusarium avena

  12. The conservation of redundancy in genetic systems: effects of sexual and asexual reproduction.

    Science.gov (United States)

    Morris, J A; Morris, R D

    2003-12-01

    The relationship between probability of survival and the number of deleterious mutations in the genome is investigated using three different models of highly redundant systems that interact with a threatening environment. Model one is a system that counters a potentially lethal infection; it has multiple identical components that act in sequence and in parallel. Model two has many different overlapping components that provide threefold coverage of a large number of vital functions. The third model is based on statistical decision theory: an ideal detector, following an optimum decision strategy, makes crucial decisions in an uncertain world. The probability of a fatal error is reduced by a redundant sampling system, but the chance of error rises as the system is impaired by deleterious mutations. In all three cases the survival profile shows a synergistic pattern in that the probability of survival falls slowly and then more rapidly. This is different than the multiplicative or independent survival profile that is often used in mathematical models. It is suggested that a synergistic profile is a property of redundant systems. Model one is then used to study the conservation of redundancy during sexual and asexual reproduction. A unicellular haploid organism reproducing asexually retains redundancy when the mutation rate is very low (0.001 per cell division), but tends to lose high levels of redundancy if the mutation rate is increased (0.01 to 0.1 per cell division). If a similar unicellular haploid organism has a sexual phase then redundancy is retained for mutation rates between 0.001 and 0.1 per cell division. The sexual organism outgrows the asexual organism when the above mutation rates apply. If they compete for finite resources the asexual organism will be extinguished. Variants of the sexual organism with increased redundancy will outgrow those with lower levels of redundancy and the sexual process facilitates the evolution of more complex forms. There is a

  13. The conservation of redundancy in genetic systems: effects of sexual and asexual reproduction

    Indian Academy of Sciences (India)

    J A Morris; R D Morris

    2003-12-01

    The relationship between probability of survival and the number of deleterious mutations in the genome is investigated using three different models of highly redundant systems that interact with a threatening environment. Model one is a system that counters a potentially lethal infection; it has multiple identical components that act in sequence and in parallel. Model two has many different overlapping components that provide threefold coverage of a large number of vital functions. The third model is based on statistical decision theory: an ideal detector, following an optimum decision strategy, makes crucial decisions in an uncertain world. The probability of a fatal error is reduced by a redundant sampling system, but the chance of error rises as the system is impaired by deleterious mutations. In all three cases the survival profile shows a synergistic pattern in that the probability of survival falls slowly and then more rapidly. This is different than the multiplicative or independent survival profile that is often used in mathematical models. It is suggested that a synergistic profile is a property of redundant systems. Model one is then used to study the conservation of redundancy during sexual and asexual reproduction. A unicellular haploid organism reproducing asexually retains redundancy when the mutation rate is very low (0.001 per cell division), but tends to lose high levels of redundancy if the mutation rate is increased (0.01 to 0.1 per cell division). If a similar unicellular haploid organism has a sexual phase then redundancy is retained for mutation rates between 0.001 and 0.1 per cell division. The sexual organism outgrows the asexual organism when the above mutation rates apply. If they compete for finite resources the asexual organism will be extinguished. Variants of the sexual organism with increased redundancy will outgrow those with lower levels of redundancy and the sexual process facilitates the evolution of more complex forms. There is a

  14. A pilot randomised trial of induced blood-stage Plasmodium falciparum infections in healthy volunteers for testing efficacy of new antimalarial drugs.

    Directory of Open Access Journals (Sweden)

    James S McCarthy

    Full Text Available BACKGROUND: Critical to the development of new drugs for treatment of malaria is the capacity to safely evaluate their activity in human subjects. The approach that has been most commonly used is testing in subjects with natural malaria infection, a methodology that may expose symptomatic subjects to the risk of ineffective treatment. Here we describe the development and pilot testing of a system to undertake experimental infection using blood stage Plasmodium falciparum parasites (BSP. The objectives of the study were to assess the feasibility and safety of induced BSP infection as a method for assessment of efficacy of new drug candidates for the treatment of P. falciparum infection. METHODS AND FINDINGS: A prospective, unblinded, Phase IIa trial was undertaken in 19 healthy, malaria-naïve, male adult volunteers who were infected with BSP and followed with careful clinical and laboratory observation, including a sensitive, quantitative malaria PCR assay. Volunteers were randomly allocated to treatment with either of two licensed antimalarial drug combinations, artemether-lumefantrine (A/L or atovaquone-proguanil (A/P. In the first cohort (n = 6 where volunteers received ∼360 BSP, none reached the target parasitemia of 1,000 before the day designated for antimalarial treatment (day 6. In the second and third cohorts, 13 volunteers received 1,800 BSP, with all reaching the target parasitemia before receiving treatment (A/L, n = 6; A/P, n = 7 The study demonstrated safety in the 19 volunteers tested, and a significant difference in the clearance kinetics of parasitemia between the drugs in the 13 evaluable subjects, with mean parasite reduction ratios of 759 for A/L and 17 for A/P (95% CI 120-4786 and 7-40 respectively; p<0.01. CONCLUSIONS: This system offers a flexible and safe approach to testing the in vivo activity of novel antimalarials. TRIAL REGISTRATION: ClinicalTrials.gov NCT01055002.

  15. Cerebral blood flow of patients with age-associated memory impairment and the early stage of Alzheimer`s disease. A study by SPECT using the ARG method

    Energy Technology Data Exchange (ETDEWEB)

    Ishiwata, Akiko; Kitamura, Shin; Nagazumi, Atushi; Terashi, Akiro [Nippon Medical School, Tokyo (Japan)

    1998-04-01

    In order to further understand the pathology of Alzheimer`s disease (AD), we have utilized image analysis in diagnosing the early stages of AD in patients with cognitive disorders. CT and MRI, however, have not been feasible since only atrophy is seen and it is difficult to differentiate the changes in AD from age associated changes. In this study we tried to determine whether regional cerebral blood flow (rCBF) measurements using single photon emission CT (SPECT) are feasible for the early diagnosis of AD. Regional CBF (rCBF) was measured using SPECT in three subject groups: Age-associated memory impairment (AAMI, n=9), mild AD (n=16), and normal aged patients (mean age=68.3; n=20). The subjects were then observed for three years. The region of interest (ROI) for the medial temporal lobe was set at OM-30deg to cover the maximum area of the hippocampus. The absolute values of rCBF in the frontal, temporal, and parietal lobes and the cerebellum were significantly lower in the mild AD subjects than in the normal aged subjects. A significant decrease in rCBF was also seen in the medial temporal lobe in both the AD and the AAMI subjects compared to the normal controls. During the three years of follow up, no cases of dementia were seen in the AAMI subjects. However, there were two patients who appeared to have difficulty in adapting to daily life due to amnesia, one with a decrease in rCBF of the medial temporal lobe on the second SPECT, and the other showing a low rCBF the first time. This study suggests that AAMI subjects may comprise both AD and normal subjects. Therefore a more prospective study is needed. (author)

  16. Nitric oxide synthetic pathway and cGMP levels are altered in red blood cells from end-stage renal disease patients.

    Science.gov (United States)

    Di Pietro, Natalia; Giardinelli, Annalisa; Sirolli, Vittorio; Riganti, Chiara; Di Tomo, Pamela; Gazzano, Elena; Di Silvestre, Sara; Panknin, Christina; Cortese-Krott, Miriam M; Csonka, Csaba; Kelm, Malte; Ferdinandy, Péter; Bonomini, Mario; Pandolfi, Assunta

    2016-06-01

    Red blood cells (RBCs) enzymatically produce nitric oxide (NO) by a functional RBC-nitric oxide synthase (RBC-NOS). NO is a vascular key regulatory molecule. In RBCs its generation is complex and influenced by several factors, including insulin, acetylcholine, and calcium. NO availability is reduced in end-stage renal disease (ESRD) and associated with endothelial dysfunction. We previously demonstrated that, through increased phosphatidylserine membrane exposure, ESRD-RBCs augmented their adhesion to human cultured endothelium, in which NO bioavailability decreased. Since RBC-NOS-dependent NO production in ESRD is unknown, this study aimed to investigate RBC-NOS levels/activation, NO production/bioavailability in RBCs from healthy control subjects (C, N = 18) and ESRD patients (N = 27). Although RBC-NOS expression was lower in ESRD-RBCs, NO, cyclic guanosine monophosphate (cGMP), RBC-NOS Serine1177 phosphorylation level and eNOS/Calmodulin (CaM)/Heat Shock Protein-90 (HSP90) interaction levels were higher in ESRD-RBCs, indicating increased enzyme activation. Conversely, following RBCs stimulation with insulin or ionomycin, NO and cGMP levels were significantly lower in ESRD- than in C-RBCs, suggesting that uremia might reduce the RBC-NOS response to further stimuli. Additionally, the activity of multidrug-resistance-associated protein-4 (MRP4; cGMP-membrane transporter) was significantly lower in ESRD-RBCs, suggesting a possible compromised efflux of cGMP across the ESRD-RBCs membrane. This study for the first time showed highest basal RBC-NOS activation in ESRD-RBCs, possibly to reduce the negative impact of decreased NOS expression. It is further conceivable that high NO production only partially affects cell function of ESRD-RBCs maybe because in vivo they are unable to respond to physiologic stimuli, such as calcium and/or insulin.

  17. Long-term oral calcium supplementation reduces diastolic blood pressure in end stage renal disease. A randomized, double-blind, placebo controlled study.

    Science.gov (United States)

    Petersen, L J; Rudnicki, M; Højsted, J

    1994-01-01

    Previous studies suggest that oral calcium supply reduces blood pressure in patients with mild to moderate hypertension. The aim of this study was to determine whether oral calcium supply reduces blood pressure in patients undergoing haemodialysis. The study was randomized, double-blind, and placebo controlled. Eleven patients received two grams of calcium per day and 12 patients received placebo. Three patients (one from the calcium group and two from the placebo group) dropped out within the first month. The groups were comparable at inclusion regarding blood pressure, weight, and serum values. Blood pressure measurements were auscultatory with a mercury manometer and diastolic blood pressure was measured as Korotkoff phase V. At inclusion a significant positive correlation between serum phosphate and blood pressure was found. After a study period of six months a significant reduction in diastolic blood pressure was found between the two groups (p < 0.05), but no difference was found in systolic blood pressure. The reduction in diastolic blood pressure was 6.9 mmHg of the pretreatment level in the calcium group. In conclusion, the treatment of secondary hyperparathyroidism with oral calcium gives good benefits in the regulation of diastolic blood pressure. A well controlled phosphate homeostasis may also be of importance for the control of blood pressure in haemodialysis patients.

  18. Estimated aortic blood pressure based on radial artery tonometry underestimates directly measured aortic blood pressure in patients with advancing chronic kidney disease staging and increasing arterial stiffness.

    Science.gov (United States)

    Carlsen, Rasmus K; Peters, Christian D; Khatir, Dinah S; Laugesen, Esben; Bøtker, Hans Erik; Winther, Simon; Buus, Niels H

    2016-10-01

    Central blood pressure (BP) can be assessed noninvasively based on radial tonometry and may potentially be a better predictor of clinical outcome than brachial BP. However, the validity of noninvasively obtained estimates has never been examined in patients with chronic kidney disease (CKD). Here we compared invasive aortic systolic BP (SBP) with estimated central SBP obtained by radial artery tonometry and examined the influence of renal function and arterial stiffness on this relationship. We evaluated 83 patients with stage 3 to 5 CKD (mean estimated glomerular filtration rate [eGFR] 30 ml/min/1.73 m(2)) and 41 controls without renal disease undergoing scheduled coronary angiography. BP in the ascending aorta was measured through the angiography catheter and simultaneously estimated using radial tonometry. The mean difference between estimated central and aortic SBP was -13.2 (95% confidence interval -14.9 to -11.4) mm Hg. Arterial stiffness was evaluated by carotid-femoral pulse wave velocity (cf-PWV) and was significantly increased in CKD patients compared with (versus) control patients (mean 10.7 vs. 9.3 m/s). The difference in BP significantly increased 1.0 mm Hg for every 10 ml/min decrease in eGFR and by 1.6 mm Hg per 1 m/s increase in cfPWV. Using multivariate regression analysis including both eGFR and cfPWV, the difference between estimated central and invasive aortic SBP was significantly increased by 0.7 mm Hg. For the entire cohort brachial SBP significantly better reflected invasive SBP than estimated SBP. Thus, tonometry-based estimates of central BP progressively underestimate invasive central SBP with decreasing renal function and increasing arterial stiffness in CKD patients.

  19. Oral lipid-based nanoformulation of tafenoquine enhanced bioavailability and blood stage antimalarial efficacy and led to a reduction in human red blood cell loss in mice

    Directory of Open Access Journals (Sweden)

    Melariri P

    2015-02-01

    Full Text Available Paula Melariri,1 Lonji Kalombo,2 Patric Nkuna,2 Admire Dube,2,3 Rose Hayeshi,2 Benhards Ogutu,4,5 Liezl Gibhard,6 Carmen deKock,6 Peter Smith,6 Lubbe Wiesner,6 Hulda Swai2 1Polymers and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Port Elizabeth, South Africa; 2Polymer and Composites, Material Science and Manufacturing, Council for Scientific and Industrial Research, Pretoria, South Africa; 3School of Pharmacy, University of the Western Cape, Bellville, South Africa; 4Centre for Research in Therapeutic Sciences, Strathmore University, Nairobi, Kenya; 5Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya; 6Division of Pharmacology, University of Cape Town Medical School, Groote Schuur Hospital, Cape Town, South Africa Abstract: Tafenoquine (TQ, a new synthetic analog of primaquine, has relatively poor bioavailability and associated toxicity in glucose-6-phosphate dehydrogenase (G6PD-deficient individuals. A microemulsion formulation of TQ (MTQ with sizes <20 nm improved the solubility of TQ and enhanced the oral bioavailability from 55% to 99% in healthy mice (area under the curve 0 to infinity: 11,368±1,232 and 23,842±872 min·µmol/L for reference TQ and MTQ, respectively. Average parasitemia in Plasmodium berghei-infected mice was four- to tenfold lower in the MTQ-treated group. In vitro antiplasmodial activities against chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum indicated no change in half maximal inhibitory concentration, suggesting that the microemulsion did not affect the inherent activity of TQ. In a humanized mouse model of G6PD deficiency, we observed reduction in toxicity of TQ as delivered by MTQ at low but efficacious concentrations of TQ. We hereby report an enhancement in the solubility, bioavailibility, and efficacy of TQ against blood stages of Plasmodium parasites without a corresponding increase in toxicity

  20. Evolution of Population with Sexual and Asexual Reproduction in Changing Environment

    Science.gov (United States)

    He, Mingfeng; Yu, Changliang; Ruan, Hongbo; Yao, Lei

    Using a lattice model based on Monte Carlo simulations, we study the role of the reproduction pattern on the fate of an evolving population. Each individual is under the selection pressure from the environment and random mutations. The habitat ("climate") is changing periodically. Evolutions of populations following two reproduction patterns are compared, asexual and sexual. We show, via Monte Carlo simulations, that sexual reproduction by keeping more diversified populations gives them better chances to adapt themselves to the changing environment. However, in order to obtain a greater chance to mate, the birth rate should be high. In the case of low birth rate and high mutation probability there is a preference for the asexual reproduction.

  1. Profiling the repertoire of phenotypes influenced by environmental cues that occur during asexual reproduction.

    Science.gov (United States)

    Dombrovsky, Aviv; Arthaud, Laury; Ledger, Terence N; Tares, Sophie; Robichon, Alain

    2009-11-01

    The aphid Acyrthosiphon pisum population is composed of different morphs, such as winged and wingless parthenogens, males, and sexual females. The combined effect of reduced photoperiodicity and cold in fall triggers the apparition of sexual morphs. In contrast they reproduce asexually in spring and summer. In our current study, we provide evidence that clonal individuals display phenotypic variability within asexual morph categories. We describe that clones sharing the same morphological features, which arose from the same founder mother, constitute a repertoire of variants with distinct behavioral and physiological traits. Our results suggest that the prevailing environmental conditions influence the recruitment of adaptive phenotypes from a cohort of clonal individuals exhibiting considerable molecular diversity. However, we observed that the variability might be reduced or enhanced by external factors, but is never abolished in accordance with a model of stochastically produced phenotypes. This overall mechanism allows the renewal of colonies from a few adapted individuals that survive drastic episodic changes in a fluctuating environment.

  2. Using a meiosis detection toolkit to investigate ancient asexual "scandals" and the evolution of sex.

    Science.gov (United States)

    Schurko, Andrew M; Logsdon, John M

    2008-06-01

    Sexual reproduction is the dominant reproductive mode in eukaryotes but, in many taxa, it has never been observed. Molecular methods that detect evidence of sex are largely based on the genetic consequences of sexual reproduction. Here we describe a powerful new approach to directly search genomes for genes that function in meiosis. We describe a "meiosis detection toolkit", a set of meiotic genes that represent the best markers for the presence of meiosis. These genes are widely present in eukaryotes, function only in meiosis and can be isolated by degenerate PCR. The presence of most, or all, of these genes in a genome would suggest they have been maintained for meiosis and, implicitly, sexual reproduction. In contrast, their absence would be consistent with the loss of meiosis and asexuality. This approach will help to understand both meiotic gene evolution and the capacity for meiosis and sex in putative obligate asexuals.

  3. The expansion of Ulva prolifera O.F. Müller macroalgal blooms in the Yellow Sea, PR China, through asexual reproduction.

    Science.gov (United States)

    Zhang, Jianheng; Kim, Jang Kyun; Yarish, Charles; He, Peimin

    2016-03-15

    Since 2007, Ulva macroalgal blooms have occurred along the coastal areas of the Yellow Sea, China. These blooms are dominated by fragments of Ulva prolifera in the early stages of development. The objectives of this study were to identify the primary mode of asexual reproduction for U. prolifera and to evaluate the contribution of these thalli fragments to the formation of blooms. Four different growth and reproductive strategies of U. prolifera segments were found including: 1) tubular diameter becoming larger; 2) formation of new branches; 3) release of zoids; and 4) polarized growth. This is the first report showing the development of numerous blade-lets from a single segment, which is remarkably different from previous studies on other Ulva species. The results in the present study provide critical information to understand how this species is able to support its explosive growth during a bloom.

  4. Implication of a Plasmodium falciparum gene in the switch between asexual reproduction and gametocytogenesis.

    Science.gov (United States)

    Gardiner, Donald L; Dixon, Matthew W A; Spielmann, Tobias; Skinner-Adams, Tina S; Hawthorne, Paula L; Ortega, Maria R; Kemp, David J; Trenholme, Katharine R

    2005-04-01

    Gametocytogenesis is fundamental for transmission of the malaria parasite Plasmodium falciparum from the human host to the mosquito vector, yet very little is understood about what triggers the switch between asexual reproduction and gametocytogenesis. Arresting the progression through the sexual cycle would block transmission of this disease. Here we identify a novel gene in P. falciparum that when genetically silenced reduces gametocyte production by a factor of 6, and when complemented up-regulates gametocyte-specific gene transcription.

  5. Monophyletic origin of multiple clonal lineages in an asexual fish (Poecilia formosa).

    Science.gov (United States)

    Stöck, Matthias; Lampert, Kathrin P; Möller, Dirk; Schlupp, Ingo; Schartl, Manfred

    2010-12-01

    Despite the advantage of avoiding the costs of sexual reproduction, asexual vertebrates are very rare and often considered evolutionarily disadvantaged when compared to sexual species. Asexual species, however, may have advantages when colonizing (new) habitats or competing with sexual counterparts. They are also evolutionary older than expected, leaving the question whether asexual vertebrates are not only rare because of their 'inferior' mode of reproduction but also because of other reasons. A paradigmatic model system is the unisexual Amazon molly, Poecilia formosa, that arose by hybridization of the Atlantic molly, Poecilia mexicana, as the maternal ancestor, and the sailfin molly, Poecilia latipinna, as the paternal ancestor. Our extensive crossing experiments failed to resynthesize asexually reproducing (gynogenetic) hybrids confirming results of previous studies. However, by producing diploid eggs, female F(1) -hybrids showed apparent preadaptation to gynogenesis. In a range-wide analysis of mitochondrial sequences, we examined the origin of P. formosa. Our analyses point to very few or even a single origin(s) of its lineage, which is estimated to be approximately 120,000 years old. A monophyletic origin was supported from nuclear microsatellite data. Furthermore, a considerable degree of genetic variation, apparent by high levels of clonal microsatellite diversity, was found. Our molecular phylogenetic evidence and the failure to resynthesize the gynogenetic P. formosa together with the old age of the species indicate that some unisexual vertebrates might be rare not because they suffer the long-term consequences of clonal reproduction but because they are only very rarely formed as a result of complex genetic preconditions necessary to produce viable and fertile clonal genomes and phenotypes ('rare formation hypothesis').

  6. Characterization of transcriptomes from sexual and asexual lineages of a New Zealand snail (Potamopyrgus antipodarum).

    Science.gov (United States)

    Wilton, Peter R; Sloan, Daniel B; Logsdon, John M; Doddapaneni, Harshavardhan; Neiman, Maurine

    2013-03-01

    Understanding the evolution and maintenance of sexual reproduction is one of the central challenges of evolutionary biology, yet we know very little about how sex influences molecular evolution. The New Zealand freshwater snail Potamopyrgus antipodarum is ideally suited to address this knowledge gap because obligately sexual individuals often coexist with multiple independently derived obligately asexual lineages. This unusual situation allows direct comparisons both between sexual and asexual P. antipodarum and across populations that differ in the relative frequency of sexual individuals. As such, P. antipodarum has received a great deal of attention as a model system for the maintenance of sex in nature and is also used as a model for environmental toxicology and biological invasions. Molecular genetic resources for P. antipodarum will thus be useful to investigators in a variety of biological fields. We used 454 sequencing of cDNA libraries to generate transcriptomes from two sexual and two asexual P. antipodarum lineages. A de novo assembly of 116.7 Mb of sequence reads produced 41 396 contigs, and sequence similarity-based Gene Ontology annotations were obtained for 3740 contigs. We detected 408 315 SNP loci and 7315 microsatellite loci, which together represent the first genome-scale resource available for P. antipodarum. Raw 454 read sequences, contig sequences, annotation data and polymorphism data are publicly available in a searchable online database and for download at http://www.biology.uiowa.edu/neiman/transcriptome.php.

  7. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    Science.gov (United States)

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  8. Observations of asexual reproductive strategies in Antarctic hexactinellid sponges from ROV video records

    Science.gov (United States)

    Teixidó, Núria; Gili, Josep-Maria; Uriz, María-J.; Gutt, Julian; Arntz, Wolf E.

    2006-04-01

    Hexactinellid sponges are one of the structuring taxa of benthic communities on the Weddell Sea shelf (Antarctica). However, little is known about their reproduction patterns (larval development, release, settlement, and recruitment), particularly in relation to sexual and asexual processes in sponge populations. Video stations obtained during several expeditions covering a wide depth range and different areas recorded a high frequency of asexual reproductive strategies (ARS) (bipartition and budding) among hexactinellids. Analysis of seabed video strips between 108 and 256 m depth, representing an area of 1400 m 2, showed that about 28% of these sponges exhibited ARS. The Rossella nuda type dominated most of the video stations and exhibited the highest proportion of budding (35%). This proportion increased with the size class. Size class >20 cm exhibited in all the stations a mean value of 8.3±0.7 (SE) for primary and of 2.5±0.2 (SE) for secondary propagules per sponge, respectively. Results from a shallow station (Stn 059, 117 m depth) showed the highest relative abundance of R. nuda type and budding (>20 cm ˜72%, 10-20 cm ˜60%, 5-10 cm ˜12%, and asexual reproduction in hexactinellid sponges may be more frequent than has been thought before and it may greatly influence the genetic structure of populations.

  9. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana

    Directory of Open Access Journals (Sweden)

    Yong-Soon Park

    2015-09-01

    Full Text Available Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  10. Unusually Large Number of Mutations in Asexually Reproducing Clonal Planarian Dugesia japonica.

    Directory of Open Access Journals (Sweden)

    Osamu Nishimura

    Full Text Available We established a laboratory clonal strain of freshwater planarian (Dugesia japonica that was derived from a single individual and that continued to undergo autotomous asexual reproduction for more than 20 years, and we performed large-scale genome sequencing and transcriptome analysis on it. Despite the fact that a completely clonal strain of the planarian was used, an unusually large number of mutations were detected. To enable quantitative genetic analysis of such a unique organism, we developed a new model called the Reference Gene Model, and used it to conduct large-scale transcriptome analysis. The results revealed large numbers of mutations not only outside but also inside gene-coding regions. Non-synonymous SNPs were detected in 74% of the genes for which valid ORFs were predicted. Interestingly, the high-mutation genes, such as metabolism- and defense-related genes, were correlated with genes that were previously identified as diverse genes among different planarian species. Although a large number of amino acid substitutions were apparently accumulated during asexual reproduction over this long period of time, the planarian maintained normal body-shape, behaviors, and physiological functions. The results of the present study reveal a unique aspect of asexual reproduction.

  11. Feeding and asexual reproduction of the jellyfish Sarsia gemmifera in response to resource enrichment.

    Science.gov (United States)

    Stibor, Herwig; Tokle, Nils

    2003-04-01

    Jellyfish are ubiquitous predators in marine pelagic environments and can sometimes control their zooplankton prey populations. Recent considerations of the fertilization of entire food webs in coastal areas make it important to investigate the response of jellyfish to resource enrichment. We investigated feeding, assimilation and life history parameters in the hydromedusa species Sarsia gemmifera. S. gemmifera was able to ingest up to 3 micro g carbon per hour, which corresponds to a daily carbon ingestion that exceeds the individual's body weight (carbon). Conversion of ingested carbon into tissue was less than 30%. The assimilated carbon was allocated such that approximately 65% was used for growth and the remainder for asexual reproduction. Carbon from food was allocated to asexually produced offspring within hours. The numerical response of S. gemmifera reached saturation at prey levels of 100 or more copepods per liter. Propagule quality was influenced by maternal effects: higher net production of the mothers in higher food environments resulted in higher carbon content of individual propagules. Starvation resistance of propagules was therefore positively related to food density in the maternal environment. The food concentrations which S. gemmifera normally experiences in the field are much lower than the food levels at which this species had its maximum asexual reproductive output in the laboratory. Therefore, S. gemmifera may potentially benefit from food web perturbations which increase crustacean zooplankton densities.

  12. Unusually Large Number of Mutations in Asexually Reproducing Clonal Planarian Dugesia japonica.

    Science.gov (United States)

    Nishimura, Osamu; Hosoda, Kazutaka; Kawaguchi, Eri; Yazawa, Shigenobu; Hayashi, Tetsutaro; Inoue, Takeshi; Umesono, Yoshihiko; Agata, Kiyokazu

    2015-01-01

    We established a laboratory clonal strain of freshwater planarian (Dugesia japonica) that was derived from a single individual and that continued to undergo autotomous asexual reproduction for more than 20 years, and we performed large-scale genome sequencing and transcriptome analysis on it. Despite the fact that a completely clonal strain of the planarian was used, an unusually large number of mutations were detected. To enable quantitative genetic analysis of such a unique organism, we developed a new model called the Reference Gene Model, and used it to conduct large-scale transcriptome analysis. The results revealed large numbers of mutations not only outside but also inside gene-coding regions. Non-synonymous SNPs were detected in 74% of the genes for which valid ORFs were predicted. Interestingly, the high-mutation genes, such as metabolism- and defense-related genes, were correlated with genes that were previously identified as diverse genes among different planarian species. Although a large number of amino acid substitutions were apparently accumulated during asexual reproduction over this long period of time, the planarian maintained normal body-shape, behaviors, and physiological functions. The results of the present study reveal a unique aspect of asexual reproduction.

  13. The importance of sexual and asexual reproduction in the recent evolution of Allium vineale.

    Science.gov (United States)

    Ceplitis, A

    2001-08-01

    In the weedy plant species Allium vineale (wild garlic), individuals may simultaneously produce sexually and asexually derived offspring, by seed and bulbils, respectively. In this study, genetic and genotypic diversity was determined in samples from 14 European A. vineale populations using nuclear (RAPD) and cytoplasmic (PCR-RFLP of cpDNA) markers to investigate the importance of the different reproductive modes. In the whole sample, 77 nuclear multilocus genotypes and four chloroplast haplotypes (chlorotypes) were found. Populations exhibited a high degree of subdivision for nuclear and cytoplasmic markers as estimated from hierarchical F-statistics; at the same time, identical chlorotypes could be found in populations separated by large distances. Genotypic diversity was significantly lower than expected under free recombination in almost all populations, indicating that recruitment into populations is mostly by asexually produced offspring. Nevertheless, within each chlorotype, the distribution of markers from pairs of nuclear loci was incompatible with a purely clonal structure, suggesting that many multilocus genotypes have originated by sexual recombination rather than by mutation within asexual lineages. It is argued that the weedy habit of A. vineale is likely to have favored bulbil reproduction, whereas sexually generated genotypes may have facilitated local adaptation during the species' expansion across Europe.

  14. Immune reactivity in early life stages of sea-cage cultured Pacific bluefin tuna naturally infected with blood flukes from genus Cardicola (Trematoda: Aporocotylidae).

    Science.gov (United States)

    Pennacchi, Ylenia; Shirakashi, Sho; Nowak, Barbara F; Bridle, Andrew R

    2016-11-01

    Pacific bluefin tuna (PBT), Thunnus orientalis, due to its high average price on the market is an economically valuable fish species. Infections by blood flukes from the genus Cardicola (Trematoda: Aporocotylidae) represent a growing concern for the cage culture of bluefin tuna in Japan, Australia and Southern Europe. The accumulation of numerous Cardicola eggs in the fish gills causes severe pathology that has been linked to mortality in PBT juveniles up to one year old. The only effective treatment used to mitigate the infection is the oral administration of the antihelminthic drug praziquantel (PZQ) to the affected fish. However, with the need to minimise therapeutic drug use in aquaculture it is hoped that immunoprophylaxis can provide a future alternative to protect the PBT juveniles against Cardicola infection. Currently, little is known of the host immune response to these parasites and of their infection dynamics. In this study, using real-time qPCR we aimed to quantitatively detect C. orientalis and C. opisthorchis DNA within the gills and heart of cultured PBT juveniles and to investigate the host immune response at the transcriptional level in the gills. The research focused mainly during early stages of infection soon after young PBT were transferred to culture cages (from 14 to 77 days post-transfer). An increase (up to 11-fold) of immune-related genes, namely IgM, MHC-I, TCR-β and IL-1β was observed in the PBT gills infected with Cardicola spp. (28-77 days post-transfer). Furthermore, IgM (19-fold increase) and MHC-I (11.5-fold increase) transcription was strongly up-regulated in gill samples of PBT infected with C. orientalis relative to uninfected fish but not in fish infected with C. opisthorchis. Cardicola-specific DNA was first detected in the host 14 days post-transfer (DPT) to sea-cages which was 55 days earlier than the first detection of parasite eggs and adults by microscopy. Oral administration of PZQ did not have an immediate effect

  15. CLINICAL OBSERVATION ABOUT THE EFFECT OF BLOOD-LETTING OF JING-POINTS ON CEREBRAL BLOOD FLOW IN STROKE PATIENTS AT THE EARLY STAGE AND EXPERIMENTAL STUDY ON ITS MECHANISMS IN THE RABBIT

    Institute of Scientific and Technical Information of China (English)

    WANG Xiuyun; REN Shusheng; GUO Yi; ZHOU Guoping; ZHOU Zhiliang; PAN Rongqing; XU Tangping; LI Qing; WANG Xin; REN Huanzhong

    2002-01-01

    In this paper,the authors sum their research resuits about the effect of blood-letting of Jing(Well)-point on cerebral blood flow both in stroke patients and in experimental cerebral ischemia,cerebral hematoma and hypertension rabbits.In 30cases of stroke (cerebral hemorrhage and cerebral infarction)patients,blood flow state of the anterior cerebral artery(ACA),middle cerebral artery(MCA)and the posterior cerebral artery (PCA), and the blood flow velocity of the bilateral vertebral artery (VA)and the basil artery(BA)are determined before and afterpricking blood of the Twelve Jing-points.In experimental cerebral ischernia (by occlusion of the common carotid ertery) rabbits ,cerebral hematoma model rabbits and intravenous injection of noradrenaline induced hypertension rabbits, rheoencephalogram(REC) is detected before and after blood letting of the twelve"Jing -points.In these 30stroke patients,ultrasound Doppler examination's results show that in 22 cases (73.33%) whose blood flow velocity decreases,after blood-letting of the 12 Jing-points, it ncreases significantly(P< 0.01); in the rest 8 cases (26.67%) whose blood flow velocity speeds up,after treatment,it decreases evidently(P<tly (P< 0.01), showing a good dual-directional regulative effect of blood -letting therapy.In experimental cerebral ischemia rabbits,cerebral hematoma rabbits and hypertension rabbits whose REG lowers in the amplitude apparently ( P < 0.01 ), after blood letting stimulation of the 12 Jing-points, it increases at different degrees.Three patterns of stimulation as blood letting stimulation, pain stimulation and Jing-point stimulation, also the 3factors of blood-letting,may contribute to their effect on improvement of the cerebral blood flow.Somatic affterent nerve,sympathetic nerve of the vasular wall,central cholinergic nerve(M receptors)and adrenergic nerve (α receptors) participate in the effect of blood letting on cerebral blood flow.

  16. Blood Types

    Science.gov (United States)

    ... maternity. Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells Platelets Plasma ... About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity ...

  17. Find out the Target IOP while Different Blood Pressure in Advanced Stage Glaucoma%晚期青光眼在不同血压段时靶眼压的选择

    Institute of Scientific and Technical Information of China (English)

    晏兴云; 贺平; 刘静

    2016-01-01

    目的:探讨晚期青光眼在不同血压段时病程的进展规律 ,并找出在不同血压段时的治疗靶眼压.方法:长期随访晚期青光眼患者的血压及眼压值 ,并分别做视野检查 ,通过A G IS评分法判断病程的进展.并统计出不同血压时的治疗靶眼压值.结果:随访血压越低 ,视野受损进展越快.当视野无进展时 ,血压越低 ,其随访眼压也越低.血压与目标眼压之间呈近似线性关系.结论:低血压是晚期青光眼病程中的危险因素之一.晚期青光眼患者对靶眼压的选择应根据不同血压段来选择.%Objective:To explore progress rule of advanced stage glaucoma and find out the target intraocular pressure in different blood pressure .Methods:Long term follow-up the intraocular pressure and blood pressure .Judge the course of glaucoma by AGIS .find out the target intraocular pressure in different blood pressure .Results:For the lower blood pressure ,impaired vision progress more quickly .When vision without progress ,the lower blood pressure ,the lower intraocular pressure there has been approximate linear relationship between blood pressure and the target intraocular pressure .Conclusion:Low blood pressure is one of the risk factors of adanced glaucoma progression .The target in-traocular pressure should be selected according to different blood pressure .

  18. Ultrastructure and function of mitochondria in gametocytic stage of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Krungkrai J.

    2000-03-01

    Full Text Available Morphological properties of the mitochondrial organelles in the asexual and sexual gametocytic stages of Plasmodium falciparum have been analyzed and found to be markedly different. From in vitro cultures of both stages in human erythrocytes, it has been demonstrated that the asexual stages contained a defined double-membrane organelle having a few tubular-like cristae. The numbers of mitochondria in the gametocytes were found to be ~ 6 organelles per parasite, and they showed a greater density of the cristae than that of the asexual stage parasite. The organelles of the gametocytes were successfully purified by differential centrifugation following Percoll density gradient separation with the results of ~ 7 % yields and ~ 5 folds. The gametocytic organelles contained much more activities of mitochondrial electron transporting enzymes (i.e., cytochrome c reductase, cytochrome c oxidase than the asexual stage organelles. Mitochondrial function as measured by oxygen consumption were found to be different between these two stages organelles. Their rates of oxygen consumption were relatively low, as compared to those of human leukocyte and mouse liver mitochondria. In contrast to the coupled mammalian mitochondria, the gametocytic organelles were in the uncoupling state between oxidation and phosphorylation reactions during their respiration. However, they were sensitive to inhibitors of the electron transport system, e.g., antimycin A, cyanide. Our results suggest that the mitochondria of the gametocytic stages are metabolically active and still underdeveloped, although their inner membranes are extensively folded. The biochemical significance of the unique structure of the mitochondria in these developing stages in host erythrocytes remains to be elucidated.

  19. Evolution of reproductive mode variation and host associations in a sexual-asexual complex of aphid parasitoids

    Directory of Open Access Journals (Sweden)

    Sandrock Christoph

    2011-12-01

    Full Text Available Abstract Background The Lysiphlebus fabarum group is a taxonomically poorly resolved complex of aphid parasitoids, presently split into three described species that comprise sexual (arrhenotokous and asexual (thelytokous lineages of unknown relationship. Specifically, it is unclear how asexuals evolved from sexuals in this system, to what extent reproductive modes are still connected by genetic exchange, how much the complex is structured by geography or by host-associated differentiation, and whether species designations are valid. Using a combination of population genetic and phylogenetic approaches, we addressed these issues in a comprehensive sample of parasitoid wasps from across Europe. Results Asexual reproduction predominated in parasitoids of the L. fabarum group, with asexual populations exhibiting high genotypic diversity. Sexual populations were only common in southern France; elsewhere sexual reproduction was restricted to specific aphid hosts. Although reproductive modes were aggregated on the mitochondrial genealogy and significantly differentiated at nuclear microsatellite loci, there was clear evidence for genetic exchange, especially on hosts attacked by sexual and asexual parasitoids. The microsatellite data further revealed that parasitoids collected from certain host aphids were significantly differentiated, yet the mitochondrial sequence variation across the entire L. fabarum group did not exceed 1.32% and exhibited a very shallow topology. Morphological characters used for delineation of described species were found to be phylogenetically non-conservative. Conclusions Our results suggest that the sexual-asexual L. fabarum group represents a young complex of lineages with incomplete isolation between reproductive modes. We propose three mechanisms of genetic exchange that may jointly explain the high genotypic diversity observed in asexual parasitoids: (i the formation of new asexual lineages via 'contagious parthenogenesis

  20. Comparative myoanatomy of cycliophoran life cycle stages

    DEFF Research Database (Denmark)

    Neves, Ricardo C.; Cunha, Marina R; Funch, Peter

    2010-01-01

    The metazoan phylum Cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. The life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. So far, the morphological and genetic...... on the dorsal side, whereas on the ventral side, longitudinal muscles and a V-shaped muscle structure are present. These muscles are complemented by additional dorsoventral muscles. The mesodermal muscle fibers attach to the cuticle via the epidermis in all life cycle stages studied herein. The musculature...... of the female is similar to that of the Pandora larva of Symbion americanus and includes dorsoventral muscles and longitudinal muscles that run in the dorsal and ventral body region. Overall, our results reveal striking similarities in the muscular arrangement of the life cycle stages of both Symbion species. J...

  1. Gene flow between sexual and facultatively asexual lineages of an aphid species and the maintenance of reproductive mode variation.

    Science.gov (United States)

    Halkett, F; Plantegenest, M; Bonhomme, J; Simon, J-C

    2008-06-01

    Many organisms considered as strictly clonal may in fact experience some rare events of sexual reproduction with their sexual relatives. However, the rate of sexual-asexual gene flow has rarely been assessed mainly because its evaluation is difficult to achieve in the field. In the cyclically parthenogenetic aphid Rhopalosiphum padi, two main sets of lineages, differing in their investment in sexual reproduction and in their genetic attributes, co-exist even at a very fine scale: the 'sexual' lineages which have a full commitment to the sexual reproduction, and the 'facultatively asexual' lineages, which allocate investment in the sexual and parthenogenetic reproduction. This system offers a unique opportunity to tackle the genetic interactions between two contrasting reproductive modes. Here, we provide evidence that gene flow occurred between sexual and facultatively asexual lineages of R. padi. We carefully examined the shuffling in phenotypic and genotypic variation following a sexual reproduction event that took place in the field. Combining genotypic data and phenotypic measurements showed that this gene mixing led to the production of a wide array of reproductive modes, including strictly asexual lineages. Finally, we discuss the central role played by facultatively asexual lineages on the maintenance of reproductive mode variation.

  2. The roles of sexual and asexual reproduction in the origin and dissemination of strains causing fungal infectious disease outbreaks.

    Science.gov (United States)

    Ashu, Eta Ebasi; Xu, Jianping

    2015-12-01

    Sexual reproduction commonly refers to the reproductive process in which genomes from two sources are combined into a single cell through mating and then the zygote genomes are partitioned to progeny cells through meiosis. Reproduction in the absence of mating and meiosis is referred to as asexual or clonal reproduction. One major advantage of sexual reproduction is that it generates genetic variation among progeny which may allow for faster adaptation of the population to novel and/or stressful environments. However, adaptation to stressful or new environments can still occur through mutation, in the absence of sex. In this review, we analyzed the relative contributions of sexual and asexual reproduction in the origin and spread of strains causing fungal infectious diseases outbreaks. The necessity of sex and the ability of asexual fungi to initiate outbreaks are discussed. We propose a framework that relates the modes of reproduction to the origin and propagation of fungal disease outbreaks. Our analyses suggest that both sexual and asexual reproduction can play critical roles in the origin of outbreak strains and that the rapid spread of outbreak strains is often accomplished through asexual expansion.

  3. Identification of genes associated with asexual reproduction in Phyllosticta citricarpa mutants obtained through Agrobacterium tumefaciens transformation.

    Science.gov (United States)

    Goulin, Eduardo Henrique; Savi, Daiani Cristina; Petters, Desirrê Alexia Lourenço; Kava, Vanessa; Galli-Terasawa, Lygia; Silva, Geraldo José; Glienke, Chirlei

    2016-11-01

    Phyllosticta citricarpa is the epidemiological agent of Citrus Black Spot (CBS) disease, which is responsible for large economic losses worldwide. CBS is characterized by the presence of spores (pycnidiospores) in dark lesions of fruit, which are also responsible for short distance dispersal of the disease. The identification of genes involved in asexual reproduction of P. citricarpa can be an alternative for directional disease control. We analyzed a library of mutants obtained through Agrobacterium tumefaciens transformation system, looking for alterations in growth and reproductive structure formation. Two mutant strains were found to have lost the ability to form pycnidia. The flanking T-DNA insertion regions were identified on P. citricarpa genome by using blast analysis and further gene prediction. The predicted genes containing the T-DNA insertions were identified as Spindle Poison Sensitivity Scp3, Ion Transport protein, and Cullin Binding proteins. The Ion Transport and Cullin Binding proteins are known to be correlated with sexual and asexual reproduction in fungi; however, the exact mechanism by which these proteins act on spore formation in P. citricarpa needs to be better characterized. The Scp3 proteins are suggested here for the first time as being associated with asexual reproduction in fungus. This protein is associated with microtubule formation, and as microtubules play an essential role as spindle machinery for chromosome segregation and cytokinesis, insertions in this gene can lead to abnormal formations, such as that observed here in P. citricarpa. We suggest these genes as new targets for fungicide development and CBS disease control, by iRNA.

  4. Asexual Reproduction of Phytophthora capsici as Affected by Extracts from Agricultural and Nonagricultural Soils.

    Science.gov (United States)

    Sanogo, S

    2007-07-01

    ABSTRACT Formation of sporangia and zoospores in species of Phytophthora is known to be influenced by soil microbial and chemical composition. In Phytophthora capsici, the study of the relationship of soil chemical composition to production of sporangia and zoospores has been limited. P. capsici is a soilborne pathogen of a wide array of vegetable crops, including chile pepper (Capsicum annuum) in New Mexico. Production of sporangia and zoospores by P. capsici was evaluated in extracts of soils from three different environments in New Mexico: (i) agricultural environments with a long history of chile pepper cropping and occurrence of P. capsici (CP), (ii) agricultural environments with no history of chile pepper cropping and no occurrence of P. capsici (Non-CP), and (iii) nonagricultural environments consisting of forests and rangelands (Non-Ag). There was a significant difference in production of P. capsici asexual propagules, expressed as natural log (number of sporangia x number of zoospores), among the three environments (P = 0.0298). Production of propagules was 9 to 13% greater in Non-Ag than in CP or Non-CP environments. Stepwise multiple discriminant analysis and canonical discriminant analysis identified the edaphic variables Na, pH, P, organic matter content, and asexual propagule production as contributing the most to the separation of the three environments. Two significant (P < 0.0001) canonical discriminant functions were derived with the first function, accounting for approximately 75% of the explained variance. Based on the two discriminant functions, approximately 93, 86, and 89% of observations in CP, Non-CP, and Non-Ag environments, respectively, were classified correctly. Soils from agricultural and nonagricultural environments differentially influence production of sporangia and zoospores in P. capsici, and soil samples could be effectively classified into agricultural and nonagricultural environments based on soil chemical properties and the

  5. [The biological reaction of inflammation, methylglyoxal of blood plasma, functional and structural alterations in elastic type arteries at the early stage of hypertension disease].

    Science.gov (United States)

    Titov, V N; Dmitriev, V A; Oshchepkov, E V; Balakhonova, T V; Tripoten', M I; Shiriaeva, Iu K

    2012-08-01

    The article deals with studying of the relationship between biologic reaction of inflammation with glycosylation reaction and content of methylglyoxal in blood serum. The positive correlation between pulse wave velocity and content of methylglyoxal, C-reactive protein in intercellular medium and malleolar brachial index value was established. This data matches the experimental results concerning involvement of biological reaction of inflammation into structural changes of elastic type arteries under hypertension disease, formation of arteries' rigidity and increase of pulse wave velocity. The arterial blood pressure is a biological reaction of hydrodynamic pressure which is used in vivo by several biological functions: biological function of homeostasis, function of endoecology, biological function of adaptation and function of locomotion. The biological reaction of hydrodynamic (hydraulic) pressure is a mode of compensation of derangement of several biological functions which results in the very high rate of hypertension disease in population. As a matter of fact, hypertension disease is a syndrome of lingering pathological compensation by higher arterial blood pressure of the biological functions derangements occurring in the distal section at the level of paracrine cenoses of cells. The arterial blood pressure is a kind of in vivo integral indicator of deranged metabolism. The essential hypertension disease pathogenically is a result of the derangement of three biological functions: biological function of homeostasis, biological function of trophology - nutrition (biological reaction of external feeding - exotrophia) and biological function of endoecology. In case of "littering" of intercellular medium in vivo with nonspecific endogenic flogogens a phylogenetically earlier activation of biological reactions of excretion, inflammation and hydrodynamic arterial blood pressure occur. In case of derangement of biological function of homeostasis, decreasing of

  6. 恶性肿瘤病人血液检查与临床分期及转移的相关性研究%The associations between blood indexes with clinical pathological stages and metastasis conditions in malignant tumor patients

    Institute of Scientific and Technical Information of China (English)

    赵晶; 游舟

    2011-01-01

    Objective To investigate the difference and relevance of complete blood count, coagulation test, albumin and globulins in different clinical pathological stages and metastasis conditions in patients with malignant tumors. Methods The complete blood count, coagulation test, albumin and globulins were compared and the relevant study was performed in patients of different clinical pathological stages and with or without metastasis. Results The different pathological stages, hemoglobin, red blood cell count, fibrinogen and white blood cell count were significantly different (P< 0. 05). The fibrinogen and white blood cell count were significantly relevant with clinical stages(r=0. 244, P<0. 05 and r=0. 220,P<0.05). The white blood cell count was significantly higher in patients with metastasis and was significantly relevant with it (r=0. 202,P<0. 05). Conclusion The fibrinogen and white blood cell count are significantly relevant with clinical pathological stages of malignant tumors, and white blood cell count is of prognostic values for them.%目的 研究恶性肿瘤患者的血常规、凝血功能及血白蛋白、球蛋白等指标在不同分期及有无转移的情况下的差异及相关性,并探讨其临床意义.方法 按不同分期及有无转移对胃癌、乳腺癌、食道癌、肾癌及肺癌等101例恶性肿瘤患者的血常规、凝血功能及血白蛋白、球蛋白等指标进行比较并进行相关性分析.结果 恶性肿瘤不同分期各指标中红细胞、血红蛋白、FIB(纤维蛋白原)及白细胞计数有明显差异(P<0.05),其中FIB含量及白细胞计数与分期明显相关(r=0.244,P<0.05;r=0.220,P<0.05);在有及无转移的情况下仅白细胞计数的差异有统计学意义(P<0.05),且明显具有相关性(r=0.202,P<0.05).结论 FIB及白细胞计数与恶性肿瘤患者的临床分期密切相关,且后者对于患者的预后具有预测价值.

  7. Comparative studies of jaw morphology and ontogeny in two species of asexually reproducing Dorvilleidae (Annelida)

    DEFF Research Database (Denmark)

    Macnaughton, M.O.; Eibye-Jacobsen, D.; Worsaae, K.

    2011-01-01

    The jaw ontogeny of Dorvillea albomaculata and D. bermudensis was studied in cultured specimens, reproducing asexually by transverse fission. Mandibular growth was found to occur by lateral apposition. Maxillary development exhibited a gradual growth pattern, as opposed to the maxillary moults...... found in closely related species (Macnaughton et al. 2009). Details of dentition and numbers of maxillary plates as well as the ontogenetic growth patterns of the jaws were found to provide significant information of systematic value. Based on detailed studies of jaw ontogeny and morphology, Dorvillea...

  8. Who runs fastest in an adaptive landscape: sexual versus asexual reproduction

    Science.gov (United States)

    Holmström, Kerstin; Jensen, Henrik Jeldtoft

    2004-06-01

    We compare the speed with which a sexual, respectively, an asexual, population is able to respond to a biased selective pressure. Our model focuses on the Weismann hypothesis that the extra variation caused by crossing-over and recombination during sexual reproduction allows a sexual population to adapt faster. We find, however, that the extra variation amongst the progeny produced during sexual reproduction for most model parameters is unable to overcome the effect that parents with a high individual fitness in general must mate with individuals of lower individual fitness resulting in a moderate reproductive fitness for the pair.

  9. On the Uselessness of Men - Comparison of Sexual and Asexual Reproduction

    Science.gov (United States)

    Stauffer, D.; Sá Martins, J. S.; de Oliveira, S. Moss

    A comparison of sexual with asexual reproduction in the Penna aging model for a single species shows the separation into males and females at a disadvantage due to the halved number of births. Also meiotic and apomictic parthenogenesis and hermaphroditism seem better than sex, even when the individuals follow the suggestion of Jan et al. to engage in sex only when their lifes are endangered by a large number of harmful mutations. In our comparison, we looked only for intrinsic effects, not for external influences like parasites or environmental catastrophes.

  10. Multigenerational demographic responses of sexual and asexual Artemia to chronic genotoxicity by a reference mutagen.

    Science.gov (United States)

    Sukumaran, Sandhya; Grant, Alastair

    2013-11-15

    Genotoxins are capable of multigenerational impacts on natural populations via DNA damage and mutations. Sexual reproduction is assumed to reduce the long term consequences of genotoxicity for individual fitness and should therefore reduce population level effects. However, rather few empirical studies have quantified the magnitude of this effect. We tried to analyse the multigenerational demographic responses of sexual Artemia franciscana and asexual Artemia parthenogenetica due to chronic genotoxicity by a reference mutagen, ethyl methane sulfonate (EMS). A prospective (elasticity analysis) and retrospective (differences and contributions) perturbation analysis was carried out to understand the interactions of life history traits with population growth rate λ by comparing elasticities, differences and contributions of vital rates to λ. None of the previous studies have compared the effects of chronic genotoxicity using prospective and retrospective perturbation analyses in a sexual and asexual species over generations. The behaviour of a population with lower growth rate in the presence of genotoxicants in the field was studied by simulating reduced fertilities in the LTRE design. The results of prospective and retrospective perturbation analyses of effects on λ showed that population growth rate was proportionally more sensitive to juvenile survival whereas the effect of EMS on juvenile fertility contributed more to the variations in population growth rate in both the species and this effect was due to the high growth rate of Artemia. Simulations of lower population growth rate in the model showed that adult fertility and survival are also of importance. Sexual reproduction substantially mitigated the long term consequences of genetic damage, although these would be greater if population growth rate were lower. So multigenerational population level consequences of genotoxicity were much greater in an asexual species. So asexual species, and those with a

  11. Bounding The Rate of Adaptation In A Large Asexually Reproducing Population With Fast Mutation Rates

    CERN Document Server

    Kelly, Michael

    2011-01-01

    We consider a model of asexually reproducing individuals. The birth and death rates of the individuals are affected by a fitness parameter. The rate of mutations that cause the fitnesses to change is proportional to the population size, $N$. The mutations may be either beneficial or deleterious. In a paper by Yu, Etheridge and Cuthbertson (2009) it was shown that the average rate at which the mean fitness increases in this model is bounded below by $\\log^{1-\\delta} N$ for any $\\delta > 0$. We achieve an upper bound on the average rate at which the mean fitness increases of $O(\\log N/\\log \\log N)$.

  12. Asexual reproduction and molecular systematics of the sea anemone Anthopleura krebsi (Actiniaria: Actiniidae).

    Science.gov (United States)

    Gomes, Paula Braga; Zamponi, Mauricio Oscar; Solé-Cava, Antonio Mateo

    2003-03-01

    In this paper we use allozyme analyses to demonstrate that individuals in Anthopleura krebsi aggregates are monoclonal. Additionally, sympatric samples of the red and the green colour-morphs of A. krebsi from Pernambuco, Brazil were genetically compared and no significant differences were observed between them (gene identity = 0.992), indicating that they do not belong to different biological species. All individuals within aggregates of the green colour-morph were found to be identical over the five polymorphic loci analysed. Such results would be extremely unlikely (P asexual reproduction in this species.

  13. Intriguing asexual life in marginal populations of the brown seaweed Fucus vesiculosus.

    Science.gov (United States)

    Tatarenkov, A; Bergström, L; Jönsson, R B; Serrão, E A; Kautsky, L; Johannesson, K

    2005-02-01

    Reproduction of attached large brown algae is known to occur only by sexual zygotes. Using microsatellites we show evolution of asexual reproduction in the bladder wrack promoting population persistence in the brackish water Baltic Sea (Fucus vesiculosus is dominated by a single clone but clonal reproduction is also present in the common form of the species. We describe a possible mechanism for vegetative reproduction of attached algae, and conclude that clonality plays an important role in persistence and dispersal of these marginal populations, in which sexual reproduction is impaired by low salinity.

  14. Effects of Ethephon, Ethylene, and 2,4-Dichlorophenoxyacetic Acid on Asexual Embryogenesis in Vitro12

    Science.gov (United States)

    Tisserat, Brent; Murashige, Toshio

    1977-01-01

    Asexual embryogenesis in Daucus carota L. `Queen Anne's Lace' callus was suppressed by Ethephon, ethylene, and 2,4-dichlorophenoxyacetic acid (2,4-D). The Ethephon effect could be attributed to volatile and nonvolatile substances. The volatile component was probably entirely ethylene. Ethylene was liberated in the cultures in direct proportion to Ethephon added to the medium. Autoclaving of Ethephon caused a substantial decrease of measurable ethylene. Continuous exposure of callus to 5 μl/l ethylene depressed somatic cell embryogenesis, but not markedly. Depression of embryogenesis by 2,4-D was unrelated to ethylene evolution. PMID:16660109

  15. Clonal T cell receptor gamma-chain gene rearrangement by PCR-based GeneScan analysis in the skin and blood of patients with parapsoriasis and early-stage mycosis fungoides.

    Science.gov (United States)

    Klemke, Claus-Detlev; Dippel, Edgar; Dembinski, Antje; Pönitz, Nina; Assaf, Chalid; Hummel, Michael; Stein, Harald; Goerdt, Sergij

    2002-07-01

    Cutaneous T cell lymphoma (CTCL) and reactive T cell skin diseases represent opposite ends of a spectrum of diseases ranging from overtly malignant to persistently benign. Within this spectrum, the parapsoriasis group is not clearly defined regarding malignant potential. In contrast to consistent findings in advanced-stage CTCL, clonality analysis of parapsoriasis has produced conflicting results in previous studies. As T cell receptor gamma-chain polymerase chain reaction GeneScan analysis (TCR-gamma-PCR-GSA) stands out by its sensitivity, its accuracy in size determination of PCR products, its capacity to identify false positives by repeated analysis and its easy applicability, this approach was used to analyse the clonality status of 41 patients with borderline T cell lymphoproliferative skin diseases, including parapsoriasis (n=27) and early-stage mycosis fungoides (MF) (n=14). A monoclonal T cell infiltrate was demonstrated by repeated TCR-gamma-PCR-GSA in lesional skin specimens in 19.2% of parapsoriasis patients and in 66.6% of early-stage MF cases (p=0.013). In peripheral blood, a monoclonal T cell population was found in a similar percentage of parapsoriasis and of early-stage MF patients (26.7% versus 12.5%; p=0.611). A detailed analysis of parapsoriasis subentities, namely small and large plaque parapsoriasis, and parapsoriasis lichenoides, revealed monoclonality in 2(6)/2(5), 3(14)/2(8) and 0(6)/0/(3) of the skin and peripheral blood specimens, respectively. The high detection rate of false positive cases by repeated analysis (20-37.5%) provides a corrected perspective for the high rates of dominant T cell clones found by others in the peripheral blood of such patients. From the results obtained, three major conclusions can be drawn: firstly, CTCL is clearly associated with detection of monoclonality, even in its early stages; secondly, monoclonality is not a prerequisite for potential CTCL precursor entities; and thirdly, recirculating malignant T

  16. Effect of surgical castration of bull calves at different stages of maturity with or without analgesia on the acute phase response (APR) and complete blood count (CBC)

    Science.gov (United States)

    The study objective was to determine if surgical castration at birth or weaning impacts the acute phase response (APR) or complete blood counts (CBC) and whether concurrent administration of an oral analgesic (meloxicam) ameliorates inflammation. Bull calves (n=29) from the University of Arkansas re...

  17. Short communication: amino acid supplementation and stage of lactation alter apparent utilization of nutrients by blood neutrophils from lactating dairy cows in vitro

    Science.gov (United States)

    Glutamine is the preferred AA used by polymorphonuclear leukocytes (PMN) during the inflammatory response. However, the effect of other AA on bovine PMN response during inflammation and how this is altered by stage of lactation has not been fully elucidated. The objective of this study was to dete...

  18. [The influence of N-stearoylethanolamine on the activity of antioxidant enzymes and on the level of stable NO metabolites in the rat testes and blood plasma at the early stages of streptozotocine-induced diabetes].

    Science.gov (United States)

    Gorid'ko, T M; Kosiakova, H V; Berdyshev, A H; Bazylians'ka, V R; Margitych, V M; Gula, N M

    2012-01-01

    The influence of N-stearoylethanolamine was investigated on the activity of enzymes of antioxidant protection and content of stable metabolites of nitric oxide (NO) in the testes and plasma of rats at the early stages of development of streptozotocine-induced diabetes mellitus. It was shown that the activity of superoxide dismutase, catalase is reduced in the plasma and testes of animals with streptozotocin-induced (50 mg/kg) diabetes (blood glucose 8-10 mmol/L). A significant increase in the amount of nitrite and nitrate anions was revealed in the plasma of rats, while only the level of nitrite was significantly changed in the testes of animals. The per os administration of the NSE aqueous suspension in a dose of 50 mg/kg during 10 days to the rats with induced diabetes contributed to the normalization of catalase activity in the testis, which correlated with a decrease in the amount of TBA-reacting products and activity of superoxide dismutase and catalase in the blood plasma of animals; the use of NSE also contributed to the reduction of nitrite content in the gonads and to normalization of both nitrite and nitrate in the blood plasma of rats. The NSE administration to intact animals caused an increase in superoxide dismutase activity and significantly reduced the content of stable NO metabolites in the blood plasma of animals.

  19. Memory and obesity affect the population dynamics of asexual freshwater planarians

    Science.gov (United States)

    Dunkel, Jörn; Talbot, Jared; Schötz, Eva-Maria

    2011-04-01

    Asexual reproduction in multicellular organisms is a complex biophysical process that is not yet well understood quantitatively. Here, we report a detailed population study for the asexual freshwater planarian Schmidtea mediterranea, which can reproduce via transverse fission due to a large stem cell contingent. Our long-term observations of isolated non-interacting planarian populations reveal that the characteristic fission waiting time distributions for head and tail fragments differ significantly from each other. The stochastic fission dynamics of tail fragments exhibits non-negligible memory effects, implying that an accurate mathematical description of future data should be based on non-Markovian tree models. By comparing the effective growth of non-interacting planarian populations with those of self-interacting populations, we are able to quantify the influence of interactions between flatworms and physical conditions on the population growth. A surprising result is the non-monotonic relationship between effective population growth rate and nutrient supply: planarians exhibit a tendency to become 'obese' if the feeding frequency exceeds a critical level, resulting in a decreased reproduction activity. This suggests that these flatworms, which possess many genes homologous to those of humans, could become a new model system for studying dietary effects on reproduction and regeneration in multicellular organisms.

  20. [The diversity of ontogeny in animals with asexual reproduction and plasticity of early development].

    Science.gov (United States)

    Isaeva, V V

    2010-01-01

    Diversity of blastogenesis and embryogenesis in animals with different reproductive strategy and different variants of the isolation of germ lineage cells, defined in the literature as preformation, epigenesis, and somatic embryogenesis, is discussed. In the course of somatic embryogenesis (or, more precisely, blastogenesis), the oozooid that has developed from the egg is naturally cloned and forms numerous genetically and morphologically identical clonal individuals or modular units of a colony. This cloning results in amplification of the parent genotype; the subsequent sexual reproduction provides for genetic recombination, and the emergence of a huge number of larvae with dispersal function provides for reproductive success. In invertebrates that reproduce asexually, no isolation of the germ cell lineage takes place; the population of stem cell capable of realizing the complete developmental program, which includes gametogenesis and blastogenesis, is represented by a diaspora of cells dispersed in the organism and possessing evolutionarily conservative features of morphofunctional organization typical to cells of the germ lineage. The plasticity of early animal embryogenesis is revealed in experiments with embryonic cells cultivated in vitro. Asexual reproduction emerged repeatedly in the course of metazoan evolution; blastogenesis in animals of different taxa is more variable and less conservative than embryogenesis, but the installation of blastogenesis into the process of early embryogenesis undermines the conservatism of embryonic development.

  1. Asexual reproduction in introduced and native populations of the ant Cerapachys biroi.

    Science.gov (United States)

    Kronauer, Daniel J C; Pierce, Naomi E; Keller, Laurent

    2012-11-01

    Asexual reproduction is particularly common among introduced species, probably because it helps to overcome the negative effects associated with low population densities during colonization. The ant Cerapachys biroi has been introduced to tropical and subtropical islands around the world since the beginning of the last century. In this species, workers can reproduce via thelytokous parthenogenesis. Here, we use genetic markers to reconstruct the history of anthropogenic introductions of C. biroi, and to address the prevalence of female parthenogenesis in introduced and native populations. We show that at least four genetically distinct lineages have been introduced from continental Asia and have led to the species' circumtropical establishment. Our analyses demonstrate that asexual reproduction dominates in the introduced range and is also common in the native range. Given that C. biroi is the only dorylomorph ant that has successfully become established outside of its native range, this unusual mode of reproduction probably facilitated the species' worldwide spread. On the other hand, the rare occurrence of haploid males and at least one clear case of sexual recombination in the introduced range show that C. biroi has not lost the potential for sex. Finally, we show that thelytoky in C. biroi probably has a genetic rather than an infectious origin, and that automixis with central fusion is the most likely underlying cytological mechanism. This is in accordance with what is known for other thelytokous eusocial Hymenoptera.

  2. Mixed asexual and sexual reproduction in the Indo-Pacific reef coral Pocillopora damicornis.

    Science.gov (United States)

    Combosch, David J; Vollmer, Steven V

    2013-09-01

    Pocillopora damicornis is one of the best studied reef-building corals, yet it's somewhat unique reproductive strategy remains poorly understood. Genetic studies indicate that P. damicornis larvae are produced almost exclusively parthenogenetically, and yet population genetic surveys suggest frequent sexual reproduction. Using microsatellite data from over 580 larvae from 13 colonies, we demonstrate that P. damicornis displays a mixed reproductive strategy where sexual and asexual larvae are produced simultaneously within the same colony. The majority of larvae were parthenogenetic (94%), but most colonies (10 of the 13) produced a subset of their larvae sexually. Logistic regression indicates that the proportion of sexual larvae varied significantly with colony size, cycle day, and calendar day. In particular, the decrease in sexual larvae with colony size suggests that the mixed reproductive strategy changes across the life of the coral. This unique shift in reproductive strategy leads to increasingly asexual replications of successful genotypes, which (in contrast to exclusive parthenogens) have already contributed to the recombinant gene pool.

  3. Genetic structure of two protist species (Myxogastria, Amoebozoa) suggests asexual reproduction in sexual Amoebae.

    Science.gov (United States)

    Fiore-Donno, Anna Maria; Novozhilov, Yuri K; Meyer, Marianne; Schnittler, Martin

    2011-01-01

    Plasmodial slime molds (Myxogastria or Myxomycetes) are common and widespread unicellular organisms that are commonly assumed to have a sexual life cycle culminating with the formation of often macroscopic fruiting bodies that efficiently disseminate spores. However, laboratory studies based on mating compatibility revealed the coexistence of asexual as well as sexual strains. To test this hypothesis in natural populations, we investigated the genetic variability of two species of the genus Lamproderma. Detailed ecological relevés were carried out in 2007 and 2009 in several deep ravines in the Elbsandsteingebirge (Saxony, south-eastern Germany). Morphological characters of 93 specimens of Lamproderma were recorded and genetic analyses, based on the small subunit ribosomal gene, the internal transcribed spacer 1 and partial elongation factor 1α sequences were carried out for 52 specimens. Genetic analyses showed the existence of two major clades, each composed of several discrete lineages. Most of these lineages were composed of several identical sequences (SSU, ITS 1 and EF-1α) which is explained best by an asexual mode of reproduction. Detrended Correspondence Analysis of morphological characters revealed two morphospecies that corresponded to the two major clades, except for one genotype (Lc6), thus challenging the morphospecies concept. Genetic patterns were not related to the geographical distribution: specimens belonging to the same genotype were found in distinct ravines, suggesting effective long-distance dispersal via spores, except for the Lc6 genotype which was found only in one ravine. Implications for the morphological and biological species concept are discussed.

  4. A lotka-volterra model of coexistence between a sexual population and multiple asexual clones.

    Science.gov (United States)

    Pound, Graeme E; Doncaster, C Patrick; Cox, Simon J

    2002-08-21

    At carrying capacity, small advantages in competitive ability can compensate a sexual population for its two-fold disadvantage in growth capacity when facing invasion by asexual mutants. In this paper, we develop a generic analytical model to consider the ecology of a sexual population comprising equal numbers of males and females, competing for shared prey resources with multiple female-only clones. We assume that the clones arise from the sexual population and are distinguished from it only by having narrower resource niches and twice the growth capacity. For sexual populations, at density-dependent carrying capacity, intra-specific competition between clonal individuals prevents them from realizing their two-fold advantage in intrinsic growth. This prediction leads to three novel outcomes: (i) a sexual population can coexist with any number of clones, provided their combined competitive impact remains less than the impact of the clones on each other; (ii) a sexual species can immediately exclude asexual invaders if it is a fast growing and strong competitor of shared resources and also has refuge in an abundant alternative resource; (iii) the rate of accumulation of clones in a sexual population will be slowed by intra and inter-specific competition amongst the clones themselves, in addition to the competitive impact from the original sexual population.

  5. Evolution of asexual reproduction in leaves of the genus Kalanchoë.

    Science.gov (United States)

    Garcês, Helena M P; Champagne, Connie E M; Townsley, Brad T; Park, Soomin; Malhó, Rui; Pedroso, Maria C; Harada, John J; Sinha, Neelima R

    2007-09-25

    Plant somatic cells have the remarkable ability to regenerate an entire organism. Many species in the genus Kalanchoë, known as "mother of thousands," develop plantlets on the leaf margins. Using key regulators of organogenesis (STM) and embryogenesis (LEC1 and FUS3) processes, we analyzed asexual reproduction in Kalanchoë leaves. Suppression of STM abolished the ability to make plantlets. Here, we report that constitutive plantlet-forming species, like Kalanchoë daigremontiana, form plantlets by coopting both organogenesis and embryogenesis programs into leaves. These species have a defective LEC1 gene and produce nonviable seed, whereas species that produce plantlets only upon stress induction have an intact LEC1 gene and produce viable seed. The latter species are basal in the genus, suggesting that induced-plantlet formation and seed viability are ancestral traits. We provide evidence that asexual reproduction likely initiated as a process of organogenesis and then recruited an embryogenesis program into the leaves in response to loss of sexual reproduction within this genus.

  6. Genetic structure of two protist species (Myxogastria, Amoebozoa suggests asexual reproduction in sexual Amoebae.

    Directory of Open Access Journals (Sweden)

    Anna Maria Fiore-Donno

    Full Text Available Plasmodial slime molds (Myxogastria or Myxomycetes are common and widespread unicellular organisms that are commonly assumed to have a sexual life cycle culminating with the formation of often macroscopic fruiting bodies that efficiently disseminate spores. However, laboratory studies based on mating compatibility revealed the coexistence of asexual as well as sexual strains. To test this hypothesis in natural populations, we investigated the genetic variability of two species of the genus Lamproderma. Detailed ecological relevés were carried out in 2007 and 2009 in several deep ravines in the Elbsandsteingebirge (Saxony, south-eastern Germany. Morphological characters of 93 specimens of Lamproderma were recorded and genetic analyses, based on the small subunit ribosomal gene, the internal transcribed spacer 1 and partial elongation factor 1α sequences were carried out for 52 specimens. Genetic analyses showed the existence of two major clades, each composed of several discrete lineages. Most of these lineages were composed of several identical sequences (SSU, ITS 1 and EF-1α which is explained best by an asexual mode of reproduction. Detrended Correspondence Analysis of morphological characters revealed two morphospecies that corresponded to the two major clades, except for one genotype (Lc6, thus challenging the morphospecies concept. Genetic patterns were not related to the geographical distribution: specimens belonging to the same genotype were found in distinct ravines, suggesting effective long-distance dispersal via spores, except for the Lc6 genotype which was found only in one ravine. Implications for the morphological and biological species concept are discussed.

  7. Multipotent epithelial cells in the process of regeneration and asexual reproduction in colonial tunicates.

    Science.gov (United States)

    Kawamura, Kazuo; Sugino, Yasuo; Sunanaga, Takeshi; Fujiwara, Shigeki

    2008-01-01

    The cellular and molecular features of multipotent epithelial cells during regeneration and asexual reproduction in colonial tunicates are described in the present study. The epicardium has been regarded as the endodermal tissue-forming epithelium in the order Enterogona, because only body fragments having the epicardium exhibit the regenerative potential. Epicardial cells in Polycitor proliferus have two peculiar features; they always accompany coelomic undifferentiated cells, and they contain various kinds of organelles in the cytoplasm. During strobilation a large amount of organelles are discarded in the lumen, and then, each tissue-forming cell takes an undifferentiated configuration. Septum cells in the stolon are also multipotent in Enterogona. Free cells with a similar configuration to the septum inhabit the hemocoel. They may provide a pool for epithelial septum cells. At the distal tip of the stolon, septum cells are columnar in shape and apparently undifferentiated. They are the precursor of the stolonial bud. In Pleurogona, the atrial epithelium of endodermal origin is multipotent. In Polyandrocarpa misakiensis, it consists of pigmented squamous cells. The cells have ultrastructurally fine granules in the cytoplasm. During budding, coelomic cells with similar morphology become associated with the atrial epithelium. Then, cells of organ placodes undergo dedifferentiation, enter a cell division cycle, and commence morphogenesis. Retinoic acid-related molecules are involved in this dedifferentiation process of multipotent cells. We conclude that in colonial tunicates two systems support the flexibility of tissue remodeling during regeneration and asexual reproduction; dedifferentiation of epithelial cells and epithelial transformation of coelomic free cells.

  8. Patterns of asexual reproduction in the fissiparous seastar Coscinasterias acutispina (Asteroidea: Echinodermata) in Japan.

    Science.gov (United States)

    Haramoto, Shinji; Komatsu, Miéko; Yamazaki, Yuji

    2007-11-01

    The morphological and anatomical characteristics of the fissiparous seastar Coscinasterias acutispina were investigated at 23 sites around Japan in order to clarify the environmental factors determining asexual reproduction. The frequency of recent fission among the sites differed, although no significant differences were evident among the three major sea areas around Japan (the Sea of Japan, Seto Inland Sea, and Pacific Ocean), indicating that the spatial variability in incidence of fission might be determined on a local scale. Morphological observations revealed that the seastars endoparasitized by Dendrogaster okadai had not undergone fission recently, suggesting that fission was suppressed by parasitism. Stepwise multiple regression analysis of the frequency of seastars that had recently undergone fission revealed that nutrient conditions affected the incidence of fission. The relationships between the pyloric caeca index and arm length ratio at the individual level suggested that good nutritional conditions were required before the occurrence of fission. Additionally, regression analysis showed that high temperature was one of the triggers of fission in C. acutispina. Thus, the process of asexual reproduction in C. acutispina appears to be governed by intricate interactions among several factors, including parasitism by D. okadai, nutrient conditions, and high temperature.

  9. Ribosomal RNA gene diversity, effective population size, and evolutionary longevity in asexual glomeromycota.

    Science.gov (United States)

    Vankuren, Nicholas W; den Bakker, Henk C; Morton, Joseph B; Pawlowska, Teresa E

    2013-01-01

    Arbuscular mycorrhizal fungi (phylum Glomeromycota) are among the oldest and most successful symbionts of land plants. With no evidence of sexual reproduction, their evolutionary success is inconsistent with the prediction that asexual taxa are vulnerable to extinction due to accumulation of deleterious mutations. To explore why Glomeromycota defy this prediction, we studied ribosomal RNA (rRNA) gene evolution in the Claroideoglomus lineage and estimated effective population size, N(e) , in C. etunicatum. We found that rRNA genes of these fungi exhibit unusual and complex patterns of molecular evolution. In C. etunicatum, these patterns can be collectively explained by an unexpectedly large N(e) combined with imperfect genome-wide and population-level rRNA gene repeat homogenization. The mutations accumulated in rRNA gene sequences indicate that natural selection is effective at purging deleterious mutations in the Claroideoglomus lineage, which is also consistent with the large N(e) of C. etunicatum. We propose that in the near absence of recombination, asexual reproduction involving massively multinucleate spores typical for Glomeromycota is responsible for the improved efficacy of selection relative to drift. We postulate that large effective population sizes contribute to the evolutionary longevity of Glomeromycota.

  10. Clonality and recombination in the life history of an asexual arbuscular mycorrhizal fungus.

    Science.gov (United States)

    den Bakker, Henk C; Vankuren, Nicholas W; Morton, Joseph B; Pawlowska, Teresa E

    2010-11-01

    Arbuscular mycorrhizal (AM) fungi in the phylum Glomeromycota colonize roots of the majority of land plants and assist them in the uptake of mineral nutrients in exchange for plant-assimilated carbon. In the absence of sexual reproductive structures and with asexual spore morphology conserved since the Ordovician, Glomeromycota may be one of the oldest eukaryotic lineages that rely predominantly on asexual reproduction for gene transmission. Clonal population structure detected in the majority of AM fungi examined to date supports this hypothesis. However, evidence of recombination found in few local populations suggests that genetic exchanges may be more common in these organisms than is currently recognized. To explore the significance of clonal expansion versus genetic recombination in the life history of modern Glomeromycota, we examined the global population of a cosmopolitan fungus Glomus etunicatum and made inferences about the population structure and the occurrence of recombination in the history of this species. We sampled eight loci from 84 isolates. We found that although the global population of G. etunicatum showed a pattern of significant differentiation, several haplotypes had a broad geographic distribution spanning multiple continents. Molecular variation among the sampled isolates indicated an overwhelmingly clonal population structure and suggested that clonal expansion plays an important role in the ecological success of modern Glomeromycota. In contrast, a pattern of homoplasy consistent with a history of recombination suggested that gene exchanges are not completely absent from the life history of these organisms, although they are likely to be very rare.

  11. The effect of population bottlenecks on mutation rate evolution in asexual populations.

    Science.gov (United States)

    Raynes, Y; Halstead, A L; Sniegowski, P D

    2014-01-01

    In the absence of recombination, a mutator allele can spread through a population by hitchhiking with beneficial mutations that appear in its genetic background. Theoretical studies over the past decade have shown that the survival and fixation probability of beneficial mutations can be severely reduced by population size bottlenecks. Here, we use computational modelling and evolution experiments with the yeast S. cerevisiae to examine whether population bottlenecks can affect mutator dynamics in adapting asexual populations. In simulation, we show that population bottlenecks can inhibit mutator hitchhiking with beneficial mutations and are most effective at lower beneficial mutation supply rates. We then subjected experimental populations of yeast propagated at the same effective population size to three different bottleneck regimes and observed that the speed of mutator hitchhiking was significantly slower at smaller bottlenecks, consistent with our theoretical expectations. Our results, thus, suggest that bottlenecks can be an important factor in mutation rate evolution and can in certain circumstances act to stabilize or, at least, delay the progressive elevation of mutation rates in asexual populations. Additionally, our findings provide the first experimental support for the theoretically postulated effect of population bottlenecks on beneficial mutations and demonstrate the usefulness of studying mutator frequency dynamics for understanding the underlying dynamics of fitness-affecting mutations.

  12. Regional cerebral blood flow in acute stage with ischemic cerebrovascular disease by xenon-133 inhalation and single photon emission computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Hiroyuki; Iino, Katsuro; Kojima, Hisashi; Saito, Hitoshi; Suzuki, Mikio; Watanabe, Kazuo; Kato, Toshiro

    1987-05-01

    Single photon emission computed tomography (SPECT) with xenon-133 inhalation method was undertaken within 48 hr after the onset in 68 patients with ischemic cerebrovascular disease. The results for regional cerebral blood flow (rCBF) were compared with concurrently available computed tomography (CT) scans. In patients with cerebral infarction, SPECT detected ischemic lesions earlier than CT, with the detectability being 92 %. The area with a decreased blood flow, as seen on SPECT, was more extensive than the low density area on CT, with a concomitant decrease in blood flow in the contralateral cerebral hemisphere. Crossed cerebellar diaschisis was associated with stenosis of the internal carotid artery in 50 % (7/14), and with stenosis of the middle cerebral artery in 35 % (9/26). Abnormal SPECT findings were seen in 47 % (8/17) of the patients with transient ischemic attack (TIA). Five TIA patients had a decreased rCBF on SPECT, which was not provided by CT scans. On the contrary, small infarct lesions in the cerebral basal ganglia, as observed in 4 patients, was not detected by SPECT, but detected by CT. This may imply the limitations of SPECT in the detection of deep-seated lesions of the cerebrum. The results led to the conclusion that SPECT can be performed safely even in acute, seriously ill patients to know changes in rCBF because it is noninvasive and is capable of being repeated in a short time. (Namekawa, K.).

  13. 早期脓毒症大鼠脑氧代谢与乳酸的变化%Preliminary study of cerebral oxygen metabolism and change of blood lactate in early stage of sepsis in rats

    Institute of Scientific and Technical Information of China (English)

    钱欣; 郑峥; 汤罗嘉; 陈锋

    2011-01-01

    Objective To observe the change of cerebral oxygen metablism and the level of blood lactate in early stage of sepsis in rats.Method Sixty-four SD rats were randomly(random number)divided into septic group and control group.The sepsis model of rat was made by lipopolysaccharide (LPS,10 mg/kg)injected intra-abdominally,and rats of control group were treated with the same amount of physiological saline instead.And each group was further divided into 4 sub-groups of4 h,6 h,12 h and 24 h after treatment.At each interval,blood samples were obtained via jugular vein for detecting blood oxygen saturation (Sjv02)and blood lactate(LA).The blood oxygen saturation(Sa02)of ventral aorta was also measured.Arteriovenous oxygen content difference (AVD02) and oxygen extraction fraction (OEF) were studied.These four variables were analyzed and compared between two groups.Results The AVD02 and OEF in sepsis group were higher than those in control groups of 3 h,6 h and 12 h (P0.05).LA in sepsis group was higher than that in control group in each interval (P0.05).脓毒症组各时间点LA含量与对照组相比均有不同程度升高,差异具有统计学意义(P<0.05).结论 脓毒症早期可出现脑贯注及脑氧摄取的增强;Sjv02,AVDO2,OEF结合LA水平的监测,能更准确的评估脓毒症早期脑供氧、耗氧和脑贯注状态.

  14. [Characteristics of the indicators of the blood coagulation and fibrinolysis systems in the pre-clinical stage of ischemic heart disease].

    Science.gov (United States)

    Andreenko, G V; Panchenko, V M; Lisina, A N; Liutova, L V

    1978-10-01

    Signs of dysfunction of the coagulation system and fibrinolysis were determined in 45 healthy young individuals who had such risk factors in relation to ischemic heart disease as arterial hypertension, hypercholesterolemia, smoking, aggravated heredity, permanent emotional overstress, etc. These signs were manifested by a tendency to augmentation of blood coagulation and compensatory activation of fibrinolysis. Ischemic-type changes were detected on the ECG after a physical load. It is assumed that dysfunction of the coagulation system and fibrinolysis is an additional risk factor in relation to ischemic heart disease, while derangement of compensatory fibrinolysis tension with the subsequent tension of its components may lead to the development of coronary thrombosis.

  15. Asexual propagation in the coral reef macroalga Halimeda (Chlorophyta, Bryopsidales) : production, dispersal and attachment of small fragments

    NARCIS (Netherlands)

    Walters, LJ; Coyer, JA; Hunter, CL; Beach, KS; Vroom, PS

    2002-01-01

    Siphonous, green macroalgae of the genus Halimeda are ubiquitous and ecologically important in tropical and subtropical marine environments. It has been hypothesized that the abundance of Halimeda on coral reefs is in part due to the ability of this genus to propagate asexually via vegetative fragme

  16. Radical modification of the A-P axis and the evolution of asexual reproduction in Convolutriloba acoels.

    Science.gov (United States)

    Sikes, James M; Bely, Alexandra E

    2008-01-01

    Acoel worms in the genus Convolutriloba are remarkable in that closely related, morphologically very similar species reproduce asexually by dramatically different processes. Transverse fission, longitudinal fission, and reversed-polarity budding all occur within this genus, indicating an unparalleled ability to alter the A-P axis. Convolutriloba thus offers an exceptional opportunity to investigate the development and evolution of asexual reproduction. Molecular phylogenetic analysis indicates that reversed-polarity budding is ancestral and fission is derived for the genus. A clear difference between budding and fission is indicated by the development of the nervous system, which forms de novo during budding, but regenerates largely by extensions of remaining components of the nervous system during both types of fission. Despite this and other differences between fission and budding, localized muscle disorganization coupled with behaviorally mediated tearing are characteristic of both transverse fission and reversed-polarity budding (though not longitudinal fission), suggesting that a homologous tissue-separation mechanism underlies these two outwardly quite different asexual reproductive modes. We suggest that the ability to split the posterior axis field into two adjacent fields, manifested during both reversed-polarity budding and longitudinal fission, may have been a driving force behind the diversification of asexual reproductive mode in this group.

  17. Protein Kinase A subunits of the ascomycete pathogen Mycosphaerella graminicola regulate asexual fructification, filamentation, melanization and osmosensing

    NARCIS (Netherlands)

    Mehrabi, R.; Kema, G.H.J.

    2006-01-01

    As in many fungi, asexual reproduction of Mycosphaerella graminicola in planta is a complex process that requires proper differentiation of the infectious hyphae in the substomatal cavities of foliar tissue before pycnidia with conidia can be formed. In this study, we have investigated the role of t

  18. Penicillium oxalicum PoFlbC regulates fungal asexual development and is important for cellulase gene expression.

    Science.gov (United States)

    Yao, Guangshan; Li, Zhonghai; Wu, Ruimei; Qin, Yuqi; Liu, Guodong; Qu, Yinbo

    2016-01-01

    Filamentous fungi can initiate vegetative growth on complex plant polysaccharides in nature through secreting a large amount of lignocellulose-degrading enzymes. These fungi develop a large amount of asexual spores to disperse and survive under harsh conditions, such as carbon and nitrogen depletion. Numerous studies report the presence of a cross-talk between asexual development and extracellular enzyme production, especially at the regulation level. This study identified and characterized a C2H2-type transcription factor called PoFlbC, which is an Aspergillus FlbC ortholog, in cellulolytic fungus Penicillium oxalicum. Results showed that the native level of PoFlbC was crucial for the normal growth and asexual development of P. oxalicum. Importantly, deletion of the PoflbC gene substantially reduced cellulase and hemicellulase productions. Comparative transcriptome analysis by RNA sequencing revealed a global downregulation of genes encoding cellulases, hemicellulases, and other proteins with functions in lignocellulose degradation. A similar defect was also observed in the OEPoflbC strain, suggesting that the production of cellulolytic enzymes was maintained by native expression of the PoflbC. In this study, an essential activator for both fungal asexual development and cellulase production was established in P. oxalicum.

  19. Increased P-35, EBI3 Transcripts and Other Treg Markers in Peripheral Blood Mononuclear Cells of Breast Cancer Patients with Different clinical Stages

    Directory of Open Access Journals (Sweden)

    Maryam Hamidinia

    2015-06-01

    Full Text Available Purpose: Currently, cancer as a major problem around the world threatens human health and has a high incidence in developing countries. Many reports have indicated that patients suffering from cancer demonstrate decreased antitumor immune responses as well as a high prevalence of T regulatory population. It has been reported that Foxp3+Tregs exert suppression by cell contact-dependent mechanisms which are mediated by soluble factors such as immunosuppressive cytokines like IL-10, TGF-​B and IL-35. Consequently there is a great need to identify prognostic and diagnostic biomarkers of regulatory T cells for vaccine and drug development. Methods: In this study IL-10, TGF-B, IL-35 and Foxp3 mRNA gene expression has been measured in peripheral blood of 40 breast cancer patients and 40 normal age-matched women using quantitative real-time PCR (qRT-PCR method with Master Mix reaction containing SYBER Green. GAPDH gene was used as housekeeping gene. Results: Our data demonstrated a significant up-regulation of IL-10, TGF-​B, P35, EBI3 and Foxp3 gene expression in patients’ peripheral blood compared to normal healthy controls (p<0.05. Conclusion: The data suggests that the immune system is suppressed in breast cancer patients, which may be due to elevated Treg cells population. These results may be useful for diagnostic or therapeutic purposes. However it may require more investigations

  20. CONFIRMATION OF HEREDITARY TYROSINEMIA TYPE 1 IN NEONATAL STAGE USING SPECTROPHOTOMETRIC MICROASSAY BASED ON THE DETERMINATION OF SUCCINYLACETONE LEVEL IN DRIED-BLOOD SPOTS

    Directory of Open Access Journals (Sweden)

    Gautam Kumar

    2014-05-01

    Full Text Available Hereditary Tyrosinemia Type 1 (HT1 is a metabolic disorder below to the class of autosomal recessive inheritance caused by the dearth of enzyme fumaryl acetoacetase the last enzyme in the tyrosine catabolic pathway . Affected individuals show increased tyrosine and succinyl acetone concentration (SA in blood. Patients also excrete increased concentration of SA in urine. The disorder is characterized by progressive liver disease and renal tubular defects with accompanying hypophosphatemic rickets. Symptoms of HT1 usually appear in the first few months of life and include failure to gain weight and grow at the expected rate, diarrhea, vomiting, yellowing of the skin and whites of the eyes (jaundice. It may also lead to liver and kidney failure and an increased risk of liver cancer. Liver transplantation is the only effective treatment for hereditary tyrosinemia type 1. In the present study, Succinyl Acetone is measured by using its inhibitory property on d-aminolaevulinate dehydratase enzyme for the diagnosis of HT1 in dried blood spots.

  1. Qi and removing blood stasis in treating early stage cirrhosis%益气化瘀法治疗早期肝硬化

    Institute of Scientific and Technical Information of China (English)

    叶思文

    2012-01-01

      目的:就益气化瘀法治疗早期肝硬化进行探讨。方法:选取三个案例进行分析,将益气健脾,活血化瘀辨证治疗肝硬化。结果:案例1:服上方治疗3个月后病愈。随访至今未见再发。案例2诸症悉除,复查肝功能,肝胆脾彩超均属正常范围。后用上方加减研末冲服月余,以巩固疗效,随访1年未见再发。案例3诸症悉除,复查肝功能及肝胆脾彩超,其中彩超示:脾脏肿大,余项均属正常范围。后用上方加减蜜丸服药月余,病告痊愈,随访2年未见再发。结论:臌胀为临床四大疑难重症之一,其病机为肝脾肾三脏功能失调,气、血、水停于腹中,本虚标实,虚实夹杂的病理过程。%  Objective:Yiqi Huayu method treatment early time liver cirrhosis of. Methods:a total of three cases were analyzed, the Qi of the spleen, promoting blood circulation to remove blood stasis syndrome differentiation and treatment of liver cirrhosis. Results:the case of 1: served 3 months after the treatment was over. Up to now no longer hair. 2 cases are in addition to all disease, the liver function, liver spleen ultrasound within the normal range. After using the above addition and subtraction grind end each month, in order to consolidate the curative effect, follow-up of 1 years again. 3 cases are in addition to all disease, the liver function and liver spleen ultrasound, including ultrasonography indicated: enlargement of spleen, the remainder were within normal range. After taking over addition and subtraction pill month, disease to cure, follow-up of 2 years showed no recurrence. Conclusion:swelling for clinical four severe problems, its pathogenesis is spleen kidney three dirty function disorders, gas, blood, water stop in the abdomen, the superficial, inclusion of actual pathological process.

  2. Candida sergipensis, a new asexual yeast species isolated from frozen pulps of tropical fruits.

    Science.gov (United States)

    Trindade, Rita C; Resende, Maria A; Pimenta, Raphael S; Lachance, Marc-André; Rosa, Carlos A

    2004-07-01

    Sixteen strains of the new yeast species Candida sergipensis have been isolated from frozen pulps of the tropical fruits umbú ( Spondias tuberosa Avr. Cam.) and mangaba ( Hancornia speciosa Gom.). Candida sergipensis was one of the prevalent species in the yeast community of these substrates. The new asexual ascomycetous yeast is phylogenetically related to Candida spandovensis and Candida sorbophila, species belonging to the Wickerhamiella clade, as evidenced by the sequences of the D1/D2 domains of their large subunit ribosomal DNAs. The species C. sergipensis and C. spandovensis can be separated on the basis of growth on 50% glucose agar, xylose and succinate, negative for the first species and positive for the second. The type culture is strain UFMG-R188 (CBS 9567).

  3. Plant germline formation: common concepts and developmental flexibility in sexual and asexual reproduction.

    Science.gov (United States)

    Schmidt, Anja; Schmid, Marc W; Grossniklaus, Ueli

    2015-01-15

    The life cycle of flowering plants alternates between two heteromorphic generations: a diploid sporophytic generation and a haploid gametophytic generation. During the development of the plant reproductive lineages - the germlines - typically, single sporophytic (somatic) cells in the flower become committed to undergo meiosis. The resulting spores subsequently develop into highly polarized and differentiated haploid gametophytes that harbour the gametes. Recent studies have provided insights into the genetic basis and regulatory programs underlying cell specification and the acquisition of reproductive fate during both sexual reproduction and asexual (apomictic) reproduction. As we review here, these recent advances emphasize the importance of transcriptional, translational and post-transcriptional regulation, and the role of epigenetic regulatory pathways and hormonal activity.

  4. Transmission of a heterologous clade C Symbiodinium in a model anemone infection system via asexual reproduction.

    Science.gov (United States)

    Chen, Wan-Nan U; Hsiao, Ya-Ju; Mayfield, Anderson B; Young, Ryan; Hsu, Ling-Lan; Peng, Shao-En

    2016-01-01

    Anemones of genus Exaiptasia are used as model organisms for the study of cnidarian-dinoflagellate (genus Symbiodinium) endosymbiosis. However, while most reef-building corals harbor Symbiodinium of clade C, Exaiptasia spp. anemones mainly harbor clade B Symbiodinium (ITS2 type B1) populations. In this study, we reveal for the first time that bleached Exaiptasia pallida anemones can establish a symbiotic relationship with a clade C Symbiodinium (ITS2 type C1). We further found that anemones can transmit the exogenously supplied clade C Symbiodinium cells to their offspring by asexual reproduction (pedal laceration). In order to corroborate the establishment of stable symbiosis, we used microscopic techniques and genetic analyses to examine several generations of anemones, and the results of these endeavors confirmed the sustainability of the system. These findings provide a framework for understanding the differences in infection dynamics between homologous and heterologous dinoflagellate types using a model anemone infection system.

  5. Genetic and environmental effects on morphology and asexual reproduction in the moss, Bryum bicolor

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, A.J. (Ithaca College, NY (USA))

    A distinctive form of Bryum bicolor, characterized by stoutly excurrent costae and abundant asexual gemmae, occurs on heavy metal-contaminated tailings of the Conrad Hill Mine in the Piedmont of North Carolina. Plants from two mine site populations, plus two other populations from Richmond, Virginia, were grown on three types of soil in order to determine the degree to which morphological traits, including the number of gemmae per plant, can be modified by substrate. All populations grew equally well in the mine soil, and there was no evidence that plants from the mine site populations were physiologically adapted for growth on the contaminated tailings. Leaf dimensions, costa length, and number of gemmae per stem were strongly influenced by substrate, although some differences between populations were maintained under experimental conditions. Populations also differed in the efficacy with which plants regenerated from gametophytic fragments.

  6. Dietary niche overlap in sympatric asexual and sexual livebearing fishes Poecilia spp.

    Science.gov (United States)

    Scharnweber, K; Plath, M; Winemiller, K O; Tobler, M

    2011-12-01

    The present study investigated the spatiotemporal patterns in trophic resource use in a system of a gynogenetic poeciliid fish, the Amazon molly Poecilia formosa, and its sexual congeners the sailfin molly Poecilia latipinna and the Atlantic molly Poecilia mexicana using gut contents analysis. No statistically significant differences in trophic resource use were found between sexual and gynogenetic species, but gut contents varied significantly across sites and over time. In addition, variation in trophic morphology (i.e. gut length) was significant across sites but not species, and laboratory experiments indicated that gut length is phenotypically plastic. Overall, trophic differentiation between coexisting asexual and sexual Poecilia appears to be minimal, and it is unlikely that niche differentiation contributes to a stable coexistence of the two reproductive forms.

  7. The More the Merrier?. Entropy and Statistics of Asexual Reproduction in Freshwater Planarians

    Science.gov (United States)

    Quinodoz, Sofia; Thomas, Michael A.; Dunkel, Jörn; Schötz, Eva-Maria

    2011-04-01

    The trade-off between traits in life-history strategies has been widely studied for sexual and parthenogenetic organisms, but relatively little is known about the reproduction strategies of asexual animals. Here, we investigate clonal reproduction in the freshwater planarian Schmidtea mediterranea, an important model organism for regeneration and stem cell research. We find that these flatworms adopt a randomized reproduction strategy that comprises both asymmetric binary fission and fragmentation (generation of multiple offspring during a reproduction cycle). Fragmentation in planarians has primarily been regarded as an abnormal behavior in the past; using a large-scale experimental approach, we now show that about one third of the reproduction events in S. mediterranea are fragmentations, implying that fragmentation is part of their normal reproductive behavior. Our analysis further suggests that certain characteristic aspects of the reproduction statistics can be explained in terms of a maximum relative entropy principle.

  8. Obsessive compulsive disorder with psychosis NOS, in an asexual male: a diagnostic challenge.

    Science.gov (United States)

    Smigas, Thomas; Nevue, Joannie; Gadit, Amin Muhammad

    2011-10-28

    A 28-year-old asexual Malaysian male presented for emergency assessment with suicidal thoughts, paranoid delusions and increasing time spent on ritualistic behaviours that included hand washing, door checking and religious chanting. His obsessions were primarily related to counting, perfectionism, contamination and chanting. The patient found himself compelled to complete numerous rituals including chanting religiously to 1000, having to restart in the event of an error during such and also described delusions of being followed by a woman who was analysing his life pattern in order to steal from him. He then started to proclaim himself to be Buddha as he believed this would keep his dead grandmother away from him, thus avoiding supposed persecution from her. Following optimisation of both escitalpram and olanzapine, a slight reduction in the patient's ritualistic behaviour and psychotic phenomenon were witnessed.

  9. Blood sugar test - blood

    Science.gov (United States)

    ... blood glucose level ( hypoglycemia ) may be due to: Hypopituitarism (a pituitary gland disorder) Underactive thyroid gland or ... tonic-clonic seizure Glucagon blood test Glucagonoma Hyperthyroidism Hypopituitarism Hypothyroidism Insulinoma Low blood sugar Multiple endocrine neoplasia ( ...

  10. RACK1 regulates mesenchymal cell recruitment during sexual and asexual reproduction of budding tunicates.

    Science.gov (United States)

    Tatzuke, Yuki; Sunanaga, Takeshi; Fujiwara, Shigeki; Kawamura, Kaz

    2012-08-15

    A homolog of receptor for activated protein kinase C1 (RACK1) was cloned from the budding tunicate Polyandrocarpa misakiensis. By RT-PCR and in situ hybridization analyses, PmRACK1 showed biphasic gene expression during asexual and sexual reproduction. In developing buds, the signal was exclusively observed in the multipotent atrial epithelium and undifferentiated mesenchymal cells that contributed to morphogenesis by the mesenchymal-epithelial transition (MET). In juvenile zooids, the signal was first observable in germline precursor cells that arose as mesenchymal cell aggregated in the ventral hemocoel. In mature zooids, the germinal epithelium in the ovary and the pharynx were the most heavily stained parts. GFP reporter assay indicated that the ovarian expression of PmRACK1 was constitutive from germline precursor cells to oocytes. To elucidate the in vivo function of PmRACK1, RNA interference was challenged. When growing buds were incubated with 5 nmol/mL siRNA, most mesenchymal cells remained round and appeared to have no interactions with the extracellular matrix (ECM), causing lower activity of MET without any apparent effects on cell proliferation. The resultant zooids became growth-deficient. The dwarf zooids did not form buds or mature gonads. Prior to RNAi, buds were treated with human BMP4 that could induce PmRACK1 expression, which resulted in MET activity. We conclude that in P. misakiensis, PmRACK1 plays roles in mesenchymal cell recruitment during formation of somatic and gonad tissues, which contributes to zooidal growth and sexual and asexual reproduction.

  11. A simple algorithm for optimization and model fitting: AGA (asexual genetic algorithm)

    Science.gov (United States)

    Cantó, J.; Curiel, S.; Martínez-Gómez, E.

    2009-07-01

    Context: Mathematical optimization can be used as a computational tool to obtain the optimal solution to a given problem in a systematic and efficient way. For example, in twice-differentiable functions and problems with no constraints, the optimization consists of finding the points where the gradient of the objective function is zero and using the Hessian matrix to classify the type of each point. Sometimes, however it is impossible to compute these derivatives and other type of techniques must be employed such as the steepest descent/ascent method and more sophisticated methods such as those based on the evolutionary algorithms. Aims: We present a simple algorithm based on the idea of genetic algorithms (GA) for optimization. We refer to this algorithm as AGA (asexual genetic algorithm) and apply it to two kinds of problems: the maximization of a function where classical methods fail and model fitting in astronomy. For the latter case, we minimize the chi-square function to estimate the parameters in two examples: the orbits of exoplanets by taking a set of radial velocity data, and the spectral energy distribution (SED) observed towards a YSO (Young Stellar Object). Methods: The algorithm AGA may also be called genetic, although it differs from standard genetic algorithms in two main aspects: a) the initial population is not encoded; and b) the new generations are constructed by asexual reproduction. Results: Applying our algorithm in optimizing some complicated functions, we find the global maxima within a few iterations. For model fitting to the orbits of exoplanets and the SED of a YSO, we estimate the parameters and their associated errors.

  12. Potato (Solanum tuberosum) greenhouse tuber production as an assay for asexual reproduction effects from herbicides.

    Science.gov (United States)

    Olszyk, David; Pfleeger, Thomas; Lee, E Henry; Plocher, Milton

    2010-01-01

    The present study determined whether young potato plants can be used as an assay to indicate potential effects of pesticides on asexual reproduction. Solanum tuberosum (Russet Burbank) plants were grown from seed pieces in a mineral soil in pots under greenhouse conditions. Plants were treated with herbicides (cloransulam, dicamba, glyphosate, imazapyr, primsulfuron, sulfometuron, or tribenuron) at simulated drift levels [asexual reproductive responses to herbicides, especially acetolactate synthase inhibitors.

  13. Relationship of prognosis and body temperature and white blood cell count in peripheral blood in early stage of patients of cerebral hemorrhage%急性脑出血患者早期体温变化及外周血白细胞计数与预后的关系

    Institute of Scientific and Technical Information of China (English)

    杨春永; 孙京莉

    2011-01-01

    目的 探讨急性脑出血患者早期体温变化及外周血白细胞计数与预后的关系.方法 将77例脑出血患者按体温与外周血白细胞计数分别分成发热组与不发热组;白细胞数正常组与白细胞数增高组;白细胞数轻度增高组与显著增高组,观察各组死亡率并进行统计学分析.结果 发热组死亡率(67.3%)高于不发热组的死亡率(20.0%)(P<0.01);白细胞数正常组死亡率(32.4%)低于白细胞数增高组的死亡率(67.4%)(P<0.01);白细胞数轻度增高组死亡率(43.5%)低于显著白细胞数增高组的死亡率(95.0%)(P<0.01).结论 根据急性脑出血患者早期体温变化及外周血白细胞计数可对预后做出较为准确的判断,且方法简单、易行,有很高的临床应用价值.%Objective To investigate the relationship of prognosis and body temperature and white blood cell count in peripheral blood in early stage of patients of cerebral hemorrhage. Methods Seventy-seven patients of cerebral hemorrhage were divided into fever group and normal temperature group, white blood cell count increasing group and normal white blood cell count group, white blood cell minimal increasing group and white blood cell increasing significantly group. Mortality of each group were calculated and compared. Results The mortality of fever group and normal temperature group was 67. 3% and 20.0% . There was significant difference between two groups ( P < 0. 01). The mortality of white blood cell count increasing group and normal white blood cell count group was 32.4% and 67.4%. There was significantly difference between two group ( P < 0.01). The mortality of white blood cell minimal increasing group and white blood cell increasing significantly group was 43. 5% and 95.0%. There was significantly difference in two group (P <0.01). Conclusion It would determine the prognosis by study body temperature and white blood cell count in peripheral blood in early stage of

  14. Specific Antibody Production by Blood B Cells is Retained in Late Stage Drug-naïve HIV-infected Africans

    Directory of Open Access Journals (Sweden)

    Lydie Béniguel

    2004-01-01

    Full Text Available Unseparated peripheral blood mononuclear cells (PBMCs obtained from drug-naïve African individuals living in a context of multi-infections and presenting with high viral load (VL, were cultured in vitro and tested for their ability to produce antibodies (Abs reacting with HIV-1 antigens. Within these PBMCs, circulating B cells were differentiated in vitro and produced IgG Abs against not only ENV, but also GAG and POL proteins. Under similar experimental conditions, HAART treated patients produced Abs to ENV proteins only. The in vitro antibody production by drug-naïve individuals' PBMCs depended on exogenous cytokines (IL-2 and IL-10 but neither on the re-stimulation of reactive cells in cultures by purified HIV-1-gp 160 antigen nor on the re-engagement of CD40 surface molecules. Further, it was not abrogated by the addition of various monoclonal Abs (mAbs to co-stimulatory molecules. This suggests that the in vitro antibody production by drug-naïve individuals' PBMCs resulted from the maturation of already envelope and core antigen-primed, differentiated B cells, presumably pre-plasma cells, which are not known to circulate at homeostasy. As in vitro produced Abs retained the capacity of binding antigen and forming complexes, this study provides pre-clinical support for functional humoral responses despite major HIV- and other tropical pathogen-induced B cell perturbations.

  15. Distribution, phenology and demography of sympatric sexual and asexual dandelions (Taraxacum officinale s.l.): geographic parthenogenesis on a small scale

    NARCIS (Netherlands)

    Verduijn, M.H.; van Dijk, P.J.; Van Damme, J.M.M.

    2004-01-01

    In many plant and animal species, sexual and asexual forms have different geographical distributions ('geographic parthenogenesis'). The common dandelion Taraxacum officinale s.l. provides a particularly clear example of differing distributions: diploid sexuals are restricted to southern and central

  16. Evidence of pheromonal constancy among sexual and asexual females in a population of fall cankerworm,Alsophila pometaria (Lepidoptera: Geometridae).

    Science.gov (United States)

    Mitter, C; Klun, J A

    1987-08-01

    The compounds (Z,Z,Z)-3,6,9-nonadecatriene (I), (Z,Z,Z,E)-(II), and (Z,Z,Z,Z)-3,6,9,11-nonadecatetraene (III) have been implicated as components of the female sex pheromone of the fall cankerworm. Chromatographie determination of the proportions of these compounds in individual females of sympatric asexual and sexual reproductive forms of the species, with concurrent analysis of the electrophoretic profiles of the same females, showed that the I: II: III proportion of compounds was constant across electrophoretically differing asexual genotypes and between these and the sexual form. Life-history characters, in contrast, typically show great variation among these genetic groups. The results indicate that pheromonal constancy is maintained in a reproductive system that is theoretically vulnerable to selective pressures that would lead to heterogeneity in the species' pheromonal communication channel.

  17. Asexual reproduction does not produce clonal populations of the brooding coral Pocillopora damicornis on the Great Barrier Reef, Australia

    Science.gov (United States)

    Sherman, C. D. H.; Ayre, D. J.; Miller, K. J.

    2006-03-01

    We have investigated the relationship between genotypic diversity, the mode of production of brooded larvae and disturbance in a range of reef habitats, in order to resolve the disparity between the reproductive mode and population structure reported for the brooding coral Pocillopora damicornis. Within 14 sites across six habitats, the ratio of the observed ( G o) to the expected ( G e) genotypic diversity ranged from 69 to 100% of that expected for random mating. At three other sites in two habitats the G o /G e ranged from 35 to 53%. Two of these sites were recently bleached, suggesting that asexual recruitment may be favoured after disturbance. Nevertheless, our data suggest that brooded larvae, from each of five habitats surveyed, were asexually produced. While clonal recruitment may be important in disturbed habitats, the lack of clonality detected, both in this and earlier surveys of 40 other sites, implies that a disturbance is normally insufficient to explain this species’ continued investment in clonal reproduction.

  18. La correlación entre la poliploidía y la reproducción asexual

    OpenAIRE

    M. Vallejo-Marín

    2014-01-01

    La poliploidía, la existencia de más de dos juegos de cromosomas apareados u homólogos, en un individuo, y la reproducción asexual por vías apomíctica o vegetativa, están fuertemente correlacionadas. Sin embargo hasta la fecha, pocos estudios han investigado directamente las hipótesis que intentan explicar el origen evolutivo de esta correlación. En esta nota, presentaré algunas de las hipótesis propuestas para explicar la correlación entre poliploidía y la reproducción asexual, y discutiré d...

  19. speciation through asexuality in fish: postzygotic reproductive isolation may be completed in spite of fertility of hybrids

    Directory of Open Access Journals (Sweden)

    Karel Janko

    2015-12-01

    Altogether, it appears that initiation of hybrid asexuality and the completion of speciation process through formation of postRIMs are interconnected phenomena. Both processes are linked to the genetic divergence of hybridizing taxa: initially, hybridization between little diverged species leads to recombinant and fertile hybrids allowing intensive gene flow. As the hybridizing taxa continue to diverge, clonally reproducing hybrid females and sterile males become dominant and the gene flow ceases. The speciation may therefore be completed through asexuality of hybrids The work was supported by grant no. 13-12580S provided by the Czech Science Foundation (www.gacr.cz. Further support was provided by the Academy of Sciences of the Czech Republic (www.cas.cz by the grant no. RVO 67985904

  20. Staging of moyamoya disease by perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo [Kyushu Univ., Fukuoka (Japan). Hospital; Matsushima, Toshio; Fukui, Masashi

    2001-04-01

    Staging of moyamoya disease, based on angiography and PET have already been established. The authors have established staging of moyamoya disease based on perfusion SPECT, that can be summarized as follows: Stage I, no abnormality is seen at rest or after acetazolamide loading; Stage II, no abnormality is seen at rest, however, a decreased response (blood flow increase rate: <15%) is seen to acetazolamide loading (a, a decreased response is seen only in the frontal lobe; b, a decreased response is seen in regions other than the frontal lobe; and c, a decreased response is seen throughout the cerebrum); Stage III, localized decrease in blood flow (blood flow decrease compared with peripheral tissue: {>=}15%) and marked decrease in response to acetazolamide (blood flow increase rate: <5%) are seen at rest. In Stage III, CT and MRI show no abnormal findings or only mild lesions of the white matter; and Stage IV, multiple decreases in blood flow are seen at rest, and CT and MRI reveal infarctions and severe atrophy at the same sites. The above staging does not require determination of cerebral blood flow, and thus it can be used in children, in whom cerebral blood flow determination is difficult. The authors performed 99m-Tc ECD perfusion SPECT in 25 patients with moyamoya disease for the staging, and compared staging based on angiography with staging based on perfusion SPECT. The results did not show a correlation between the 2 staging methods. A problem inherent in the staging of moyamoya disease based on perfusion SPECT is that the relationship between cerebral blood flow and cerebral radioactivity concentrations may differ depending on the drug used to determine cerebral blood flow. Thus, although the present staging system does not depend on any specific radioactive drug to determine cerebral blood flow, further investigation is necessary to identify a more appropriate drug than those in current use. (K.H.)

  1. Dynamic formation of asexual diploid and polyploid lineages: multilocus analysis of Cobitis reveals the mechanisms maintaining the diversity of clones.

    Directory of Open Access Journals (Sweden)

    Karel Janko

    Full Text Available Given the hybrid genomic constitutions and increased ploidy of many asexual animals, the identification of processes governing the origin and maintenance of clonal diversity provides useful information about the evolutionary consequences of interspecific hybridization, asexuality and polyploidy. In order to understand the processes driving observed diversity of biotypes and clones in the Cobitis taenia hybrid complex, we performed fine-scale genetic analysis of Central European hybrid zone between two sexual species using microsatellite genotyping and mtDNA sequencing. We found that the hybrid zone is populated by an assemblage of clonally (gynogenetically reproducing di-, tri- and tetraploid hybrid lineages and that successful clones, which are able of spatial expansion, recruit from two ploidy levels, i.e. diploid and triploid. We further compared the distribution of observed estimates of clonal ages to theoretical distributions simulated under various assumptions and showed that new clones are most likely continuously recruited from ancestral populations. This suggests that the clonal diversity is maintained by dynamic equilibrium between origination and extinction of clonal lineages. On the other hand, an interclonal selection is implied by nonrandom spatial distribution of individual clones with respect to the coexisting sexual species. Importantly, there was no evidence for sexually reproducing hybrids or clonally reproducing non-hybrid forms. Together with previous successful laboratory synthesis of clonal Cobitis hybrids, our data thus provide the most compelling evidence that 1 the origin of asexuality is causally linked to interspecific hybridization; 2 successful establishment of clones is not restricted to one specific ploidy level and 3 the initiation of clonality and polyploidy may be dynamic and continuous in asexual complexes.

  2. Genotyping an Emiliania huxleyi (prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction

    Science.gov (United States)

    Krueger-Hadfield, S. A.; Balestreri, C.; Schroeder, J.; Highfield, A.; Helaouët, P.; Allum, J.; Moate, R.; Lohbeck, K. T.; Miller, P. I.; Riebesell, U.; Reusch, T. B. H.; Rickaby, R. E. M.; Young, J.; Hallegraeff, G.; Brownlee, C.; Schroeder, D. C.

    2014-09-01

    Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to species that have large population sizes and rapid generation times, such that the genetic variation required for adaptive evolution can be readily supplied. Emiliania huxleyi (Lohm.) Hay and Mohler (Prymnesiophyceae) is likely to be such a species, as it is the most conspicuous extant calcareous phytoplankton species in our oceans with growth rates of 1 day-1. Here we report on a validated set of microsatellites, in conjunction with the coccolithophore morphology motif genetic marker, to genotype 93 clonal isolates collected from across the world. Of these, 52 came from a single bloom event in the North Sea collected on the D366 United Kingdom Ocean Acidification cruise in June-July 2011. There were 26 multilocus genotypes (MLGs) encountered only once in the North Sea bloom and 8 MLGs encountered twice or up to six times. Each of these repeated MLGs exhibited Psex values of less than 0.05, indicating each repeated MLG was the product of asexual reproduction and not separate meiotic events. In addition, we show that the two most polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions likely undergoing rapid genetic drift during asexual reproduction. Despite the small sample size, there were many more repeated genotypes than previously reported for other bloom-forming phytoplankton species, including a previously genotyped E. huxleyi bloom event. This study challenges the current assumption that sexual reproduction predominates during bloom events. Whilst genetic diversity is high amongst extant populations of E. huxleyi, the root cause for this diversity and ultimate fate of these populations still

  3. Genotyping an Emiliania huxleyi (Prymnesiophyceae bloom event in the North Sea reveals evidence of asexual reproduction

    Directory of Open Access Journals (Sweden)

    S. A. Krueger-Hadfield

    2014-03-01

    Full Text Available Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to species that have large population sizes and rapid generation times, such that the genetic variation required for adaptive evolution can be readily supplied. Emiliania huxleyi (Lohm. Hay and Mohler (Prymnesiophyceae is likely to be such a species as it is the most conspicuous extant calcareous phytoplankton species in our oceans with generation times of 1 day−1. Here we report on a validated set of microsatellites, in conjunction with the coccolithophore morphology motif genetic marker, to genotype 93 clonal isolates collected from across the world. Of these, 52 came from a single bloom event in the North Sea collected on the D366 UK Ocean Acidification cruise in June-July 2011. There were 26 multilocus genotypes (MLGs encountered only once in the North Sea bloom and 8 MLGs encountered twice or up to six times. Each of these repeated MLGs exhibited Psex values of less than 0.05 indicating each repeated MLG was the product of asexual reproduction and not separate meiotic events. In addition, we show that the two most polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions likely undergoing rapid genetic drift during asexual reproduction. Despite the small sample size, there were many more repeated genotypes than previously reported for other bloom-forming phytoplankton species, including a previously genotyped E. huxleyi bloom event. This study challenges our current assumption that sex is the predominant mode of reproduction during bloom events. Whilst genetic diversity is high amongst extant populations of E. huxleyi, the root cause for this diversity and ultimate fate of these

  4. Well staged

    Energy Technology Data Exchange (ETDEWEB)

    Budd, Godfrey

    2011-06-15

    Packers Plus Energy Services Inc. has commercially launched QuickFRAC, a multi-stage completition system which can fracture four to five isolated stages in one treatment and set up a record of 23-stage slickwater frac in less than 10 hours. It could take up to 40 days to do 100 fracture treatments with other systems. This technology makes it possible to distribute fluid at each port thanks to the limited entry system. In order to make multiple isolated stages within one treatment zone, each zone includes multiple QuickPORT sleeves with packers on either side. The other technology which made this possible is the repeater port system, it allows them to perform more frac stages. This technology could be useful in the future since the need for stages will be doubling soon with microdarcy shale oil extraction which is more difficult than gas.

  5. Effect of tropical storms on sexual and asexual reproduction in coral Pocillopora verrucosa subpopulations in the Gulf of California

    Science.gov (United States)

    Aranceta-Garza, F.; Balart, E. F.; Reyes-Bonilla, H.; Cruz-Hernández, P.

    2012-12-01

    Pocillopora verrucosa is a branching, reef-building coral, and a simultaneous hermaphrodite that reproduces sexually and asexually by fragmentation. In the Gulf of California, local P. verrucosa populations have mixed modes of reproduction which vary in frequency by site. Sexual and asexual reproductions were assessed using multi-locus genotypes deriving from six microsatellite loci at every location. Clone frequencies varied from 0.30 at Loreto to 0.96 in the San Lorenzo Channel. Isla Espíritu Santo and the San Lorenzo Channel were mostly asexual subpopulations, presented the lowest genotypic richness ( N g / N = 0.1-0.12) and genotypic diversity ( G o / G e = 0.04), and were dominated by one or two multi-loci genotypes ( G o / N g = 0.35-0.45). Loreto, El Portugués, and Cabo Pulmo were mostly sexual with high Ng/ N (0.80-0.74) and G o / G e (0.52-0.58) and did not show domination by a single multi-locus genotype ( G o / N g = 0.70-0.74). There was a significant relationship ( P reproduction modes has different maintenance strategies at a regional and even local level among populations indicating the crucial role that storms play in population structure.

  6. La correlación entre la poliploidía y la reproducción asexual

    Directory of Open Access Journals (Sweden)

    M. Vallejo-Marín

    2014-01-01

    Full Text Available La poliploidía, la existencia de más de dos juegos de cromosomas apareados u homólogos, en un individuo, y la reproducción asexual por vías apomíctica o vegetativa, están fuertemente correlacionadas. Sin embargo hasta la fecha, pocos estudios han investigado directamente las hipótesis que intentan explicar el origen evolutivo de esta correlación. En esta nota, presentaré algunas de las hipótesis propuestas para explicar la correlación entre poliploidía y la reproducción asexual, y discutiré de qué forma los análisis filogenéticos nos pueden ayudar para establecer la fuerza y la causalidad de esta asociación. Adicionalmente, presentaré un ejemplo de cómo sistemas alopoliploides de evolución reciente pueden servir para estudiar la interacción entre poliploidía y la reproducción asexual, y para probar hipótesis específicas derivadas de estudios correlativos y comparativos.

  7. A novel invertebrate trophic factor related to invertebrate neurotrophins is involved in planarian body regional survival and asexual reproduction.

    Science.gov (United States)

    Bueno, David; Fernàndez-Rodríguez, Juana; Cardona, Albert; Hernàndez-Hernàndez, Victor; Romero, Rafael

    2002-12-15

    Trophic factors are a heterogeneous group of molecules that promote cell growth and survival. In freshwater planarians, the small secreted protein TCEN49 is linked to the regional maintenance of the planarian central body region. To investigate its function in vivo, we performed loss-of-function and gain-of-function experiments by RNA interference and by the implantation of microbeads soaked in TCEN49, respectively. We show that TCEN49 behaves as a trophic factor involved in central body region neuron survival. In planarian tail regenerates, tcen49 expression inhibition by double-stranded RNA interference causes extensive apoptosis in various cell types, including nerve cells. This phenotype is rescued by the implantation of microbeads soaked in TCEN49 after RNA interference. On the other hand, in organisms committed to asexual reproduction, both tcen49 mRNA and its protein are detected not only in the central body region but also in the posterior region, expanding from cells close to the ventral nerve chords. In some cases, the implantation of microbeads soaked in TCEN49 in the posterior body region drives organisms to reproduce asexually, and the inhibition of tcen49 expression obstructs this process, suggesting a link between the central nervous system, TCEN49, regional induction, and asexual reproduction. Finally, the distribution of TCEN49 cysteine and tyrosine residues also points to a common evolutionary origin for TCEN49 and molluscan neurotrophins.

  8. The role of sexual and asexual reproduction in structuring high latitude populations of the reef coral Pocillopora damicornis.

    Science.gov (United States)

    Miller, K J; Ayre, D J

    2004-06-01

    The genotypic composition of populations of the asexually viviparous coral Pocillopora damicornis varies in a manner that challenges classical models of the roles of sexual and asexual reproduction. On the geographically isolated Hawaiian reefs and high latitude reefs in Western Australia, P. damicornis populations are highly clonal although it has been argued that sexual reproduction via broadcast spawning generates widely dispersed colonists. In contrast, on eastern Australia's tropical Great Barrier Reef populations show little evidence of clonality. Here, we compare the genotypic diversity of adult and juvenile colonies of P. damicornis at seven sites on eastern Australia's high latitude Lord Howe Island reefs to determine if levels of clonality vary with habitat heterogeneity and age of colonies (as predicted by theory) or alternatively if clonality is again always high as for other isolated reef systems. We found 55-100% of the genotypic diversity expected for random mating at all seven sites and little evidence of asexual recruitment irrespective of habitat heterogeneity (sheltered versus wave exposed) or colony age. We found reduced levels of genetic diversity compared with tropical reefs (2.75 versus 4 alleles/locus), which supports earlier findings that Lord Howe Island is an isolated reef system. Furthermore, heterozygote deficits coupled with significant genetic subdivision among sites (FST=0.102+/-0.03) is typical of populations that have limited larval connections and are inbred. We conclude that the genetic structure of P. damicornis at Lord Howe Island reflects populations that are maintained through localised recruitment of sexually produced larvae.

  9. Distribution of Phoxinus eos, Phoxinus neogaeus, and their asexually-reproducing hybrids (Pisces: Cyprinidae in Algonquin Provincial Park, Ontario.

    Directory of Open Access Journals (Sweden)

    Jonathan A Mee

    Full Text Available Hybrid Phoxinus are one of the few asexually reproducing vertebrates species. The distribution of hybrid Phoxinus among lakes in Algonquin Park, Ontario, was evaluated relative to the distribution of parental species and relative to physiochemical lake characteristics. No association between the distribution of hybrids and the distribution of parental species was found, suggesting that the hybrids can successfully coexist with either parental species. In addition, we found no association between hybrid distribution and the physiochemical characteristics of lakes, suggesting that the hybrids are generalists with respect to the ecological niches available in Algonquin Park. There was a difference between the physiochemical characteristics of lakes with and without the parental species P. neogaeus. The lakes containing P. neogaeus were lower elevation than the lakes containing the other parental species, P. eos. The difference in distribution between the parental species may therefore be due to different dispersal abilities, to later arrival following post-glacial dispersal, or to differences in ecology. These results suggest that asexual reproduction is a successful strategy for hybrid Phoxinus in Algonquin Park because these sperm-dependent asexual hybrids are able to survive and persist regardless of which parental species is present, and regardless of the physiochemical characteristics of their habitat.

  10. Trading stages

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2012-01-01

    Interest in stage-and age structured models has recently increased because they can describe quantitative traits such as size that are left out of age-only demography. Available methods for the analysis of effects of vital rates on lifespan in stage-structured models have not been widely applied ...... examples. Much of our approach relies on trading of time and mortality risk in one stage for time and risk in others. Our approach contributes to the new framework of the study of age- and stage-structured biodemography....

  11. Boxer crabs induce asexual reproduction of their associated sea anemones by splitting and intraspecific theft.

    Science.gov (United States)

    Schnytzer, Yisrael; Giman, Yaniv; Karplus, Ilan; Achituv, Yair

    2017-01-01

    Crabs of the genus Lybia have the remarkable habit of holding a sea anemone in each of their claws. This partnership appears to be obligate, at least on the part of the crab. The present study focuses on Lybia leptochelis from the Red Sea holding anemones of the genus Alicia (family Aliciidae). These anemones have not been found free living, only in association with L. leptochelis. In an attempt to understand how the crabs acquire them, we conducted a series of behavioral experiments and molecular analyses. Laboratory observations showed that the removal of one anemone from a crab induces a "splitting" behavior, whereby the crab tears the remaining anemone into two similar parts, resulting in a complete anemone in each claw after regeneration. Furthermore, when two crabs, one holding anemones and one lacking them, are confronted, the crabs fight, almost always leading to the "theft" of a complete anemone or anemone fragment by the crab without them. Following this, crabs "split" their lone anemone into two. Individuals of Alicia sp. removed from freshly collected L. leptochelis were used for DNA analysis. By employing AFLP (Fluorescence Amplified Fragments Length Polymorphism) it was shown that each pair of anemones from a given crab is genetically identical. Furthermore, there is genetic identity between most pairs of anemone held by different crabs, with the others showing slight genetic differences. This is a unique case in which one animal induces asexual reproduction of another, consequently also affecting its genetic diversity.

  12. A simple algorithm for optimization and model fitting: AGA (asexual genetic algorithm)

    CERN Document Server

    Canto, J; Martinez-Gomez, E; 10.1051/0004-6361/200911740

    2009-01-01

    Context. Mathematical optimization can be used as a computational tool to obtain the optimal solution to a given problem in a systematic and efficient way. For example, in twice-differentiable functions and problems with no constraints, the optimization consists of finding the points where the gradient of the objective function is zero and using the Hessian matrix to classify the type of each point. Sometimes, however it is impossible to compute these derivatives and other type of techniques must be employed such as the steepest descent/ascent method and more sophisticated methods such as those based on the evolutionary algorithms. Aims. We present a simple algorithm based on the idea of genetic algorithms (GA) for optimization. We refer to this algorithm as AGA (Asexual Genetic Algorithm) and apply it to two kinds of problems: the maximization of a function where classical methods fail and model fitting in astronomy. For the latter case, we minimize the chi-square function to estimate the parameters in two e...

  13. Facultative asexual reproduction and genetic diversity of populations in the humivorous termite Cavitermes tuberosus.

    Science.gov (United States)

    Fournier, Denis; Hellemans, Simon; Hanus, Robert; Roisin, Yves

    2016-06-15

    Termite colonies are typically founded by a pair of sexually reproducing dispersers, which can sometimes be replaced by some of their offspring. Some Reticulitermes and Embiratermes species routinely practice asexual queen succession (AQS): the queen is replaced by neotenic daughters produced by parthenogenesis, which mate with the primary king. Here, to cast light on the evolution of AQS, we investigated another candidate species, Cavitermes tuberosus (Termitinae). Of 95 nests, 39 contained a primary queen and 28 contained neotenic females (2-667 individuals), usually with the primary king. Microsatellite analyses confirmed that colonies were initiated by single pairs after large dispersal flights. More than 80% of the neotenic females were of exclusively maternal origin and completely homozygous, suggesting automictic parthenogenesis with gamete duplication. Conversely, workers, soldiers, and most alates and primary reproductives were produced sexually. AQS often occurs late, after colonies have reached maturity, whereas early AQS in other species may boost the young colony's growth rate. We suggest additional benefits of AQS in C. tuberosus, related with a smaller size, lesser stability and higher mobility of colonies. Our data add to the phylogenetical dispersion and diversity of modalities of AQS in termites, supporting a multiple evolutionary origin of this process.

  14. Defining pheromone-receptor signaling in Candida albicans and related asexual Candida species.

    Science.gov (United States)

    Lin, Ching-Hsuan; Choi, Anthony; Bennett, Richard J

    2011-12-01

    Candida albicans is an important human fungal pathogen in which sexual reproduction is under the control of the novel white-opaque switch. Opaque cells are the mating-competent form, whereas white cells do not mate but can still respond to pheromones, resulting in biofilm formation. In this study, we first define the domains of the α-pheromone receptor Ste2 that are necessary for signaling in both white and opaque forms. Both cell states require the IC loop 3 (IC3) and the C-terminal tail of Ste2 for the cellular response, whereas the first IC loop (IC1) of Ste2 is dispensable for signaling. To also address pheromone-receptor interactions in related species, including apparently asexual Candida species, Ste2 orthologues were heterologously expressed in Candida albicans. Ste2 receptors from multiple Candida clade species were functional when expressed in C. albicans, whereas the Ste2 receptor of Candida lusitaniae was nonfunctional. Significantly, however, expression of a chimeric C. lusitaniae Ste2 receptor containing the C-terminal tail of Ste2 from C. albicans generated a productive response to C. lusitaniae pheromone. This system has allowed us to characterize pheromones from multiple Candida species and indicates that functional pheromone-receptor couples exist in fungal species that have yet to be shown to undergo sexual mating.

  15. Expression and function of myc during asexual reproduction of the budding ascidian Polyandrocarpa misakiensis.

    Science.gov (United States)

    Fujiwara, Shigeki; Isozaki, Takaomi; Mori, Kyoko; Kawamura, Kazuo

    2011-12-01

    The budding ascidian Polyandrocarpa misakiensis proliferates asexually by budding. The atrial epithelium is a multipotent but differentiated tissue, which transdifferentiates into various tissues and organs after the bud separates from the parental body. We isolated cDNA clones homologous to the myc proto-oncogene from P. misakiensis. The cDNA, named Pm-myc, encoded a polypeptide of 639 amino acid residues, containing Myc-specific functional motifs, Myc box I and Myc box II, and the basic helix-loop-helix domain. Expression of Pm-myc was observed in the atrial epithelium in the organ-forming region of the developing bud, where the epithelial cells dedifferentiate and re-enter the cell cycle. The expression was also observed in fibroblast-like cells, which are known to participate in the organogenesis together with the epithelial cells. Unexpectedly, the atrial epithelium expressed Pm-myc more than one day before the dedifferentiation. The organogenesis was disturbed by Pm-myc-specific double-stranded RNA. In situ hybridization revealed that Pm-myc-positive fibroblast-like cells disappeared around the organ primordium of the dsRNA-treated bud. The results suggest that the mesenchymal-epithelial transition of fibroblast-like cells is important for the organogenesis in this budding ascidian species.

  16. Asexual reproduction in a close relative of Arabidopsis: a genetic investigation of apomixis in Boechera (Brassicaceae).

    Science.gov (United States)

    Schranz, M Eric; Kantama, Laksana; de Jong, Hans; Mitchell-Olds, Thomas

    2006-01-01

    Understanding apomixis (asexual reproduction through seeds) is of great interest to both plant breeders and evolutionary biologists. The genus Boechera is an excellent system for studying apomixis because of its close relationship to Arabidopsis, the occurrence of apomixis at the diploid level, and its potentially simple inheritance by transmission of a heterochromatic (Het) chromosome. Diploid sexual Boechera stricta and diploid apomictic Boechera divaricarpa (carrying a Het chromosome) were crossed. Flow cytometry, karyotype analysis, genomic in situ hybridization, pollen staining and seed-production measurements were used to analyse the parents and resulting F1, F2 and selected F3 and test-cross (TC) generations. The F1 plant was a low-fertility triploid that produced a swarm of aneuploid and polyploid F2 progeny. Two of the F2 plants were fertile near-tetraploids, and analysis of their F3 and TC progeny revealed that they were sexual and genomically stabilized. The apomictic phenotype was not transmitted by genetic crossing as a single dominant locus on the Het chromosome, suggesting a complex genetic control of apomixis that has implications for future genetic and evolutionary analyses in this group.

  17. Mutualism and asexual reproduction influence recognition genes in a fungal symbiont.

    Science.gov (United States)

    van der Nest, Magriet A; Steenkamp, Emma T; Wilken, Markus P; Stenlid, Jan; Wingfield, Mike J; Wingfield, Brenda D; Slippers, Bernard

    2013-06-01

    Mutualism between microbes and insects is common and alignment of the reproductive interests of microbial symbionts with this lifestyle typically involves clonal reproduction and vertical transmission by insect partners. Here the Amylostereum fungus-Sirex woodwasp mutualism was used to consider whether their prolonged association and predominance of asexuality have affected the mating system of the fungal partner. Nucleotide information for the pheromone receptor gene rab1, as well as the translation elongation factor 1α gene and ribosomal RNA internal transcribed spacer region were utilized. The identification of rab1 alleles in Amylostereum chailletii and Amylostereum areolatum populations revealed that this gene is more polymorphic than the other two regions, although the diversity of all three regions was lower than what has been observed in free-living Agaricomycetes. Our data suggest that suppressed recombination might be implicated in the diversification of rab1, while no evidence of balancing selection was detected. We also detected positive selection at only two codons, suggesting that purifying selection is important for the evolution of rab1. The symbiotic relationship with their insect partners has therefore influenced the diversity of this gene and influenced the manner in which selection drives and maintains this diversity in A. areolatum and A. chailletii.

  18. La identidad asexual: de la masculinización social a las redes sociales virtuales

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    Mª Teresa López Ruiz

    2015-01-01

    Full Text Available En el marco de una tesis doctoral a propósito de la aparición, en la escena social, de la nueva identidad asexual, el presente trabajo indaga en los principales factores socio-culturales que pueden haber incidido en su desarrollo. Una identidad que se elabora intersubjetivamente ante nuestros ojos en el seno de una comunidad virtual y a la que, por tanto, no le pueden ser ajenos factores como las posibilidades que ofrecen actualmente las tecnologías de la información y la comunicación. Las nuevas redes sociales comienzan así a mostrarse, no sólo como instrumentos útiles para impulsar algunos cambios en las políticas públicas, o no sólo como generadoras de nuevas formas de comunicación, conocimiento y saber, sino como espacios donde se elaboran y se transmiten cambios, incluso en los aspectos que parecerían más íntimos del ser humano, como la propia sexualidad, en cuya normatividad ha enraizado siempre el deber ser- esto es, la identidad- de mujeres y hombres.

  19. TECHNOLOGICAL ASPECTS CONCERNING PRODUCTION ON ASEXUAL TRACK OF ORNAMENTAL CULTURE OF ALOE ARBORESCENS

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    Mădălina Doltu

    2012-12-01

    Full Text Available Research conducted in culture of Aloe arborescens Mill., in conditions of protected area (greenhouse, had to watch some of technological aspects to obtain some in pot ornamentals plants, competitive plants for european market. Experience has included plants of Aloe arborescens Mill., aged 1-5 years, obtained by vegetative multiplying, asexual. Production technology was applied to aloe plants (multiplying, transplanting, maintenance, taking into account the ecological requirements of specie and possibilities of using automated artificial factors influencing microclimate (shading, ventilation, cooling of production space. Researches has established technological aspects concerning production of plants, to satisfy requirements of specie, for obtained some specimens by superior decorative quality. The results of experienced technology indicate quality of morphological characters, growth increases important of decorative elements (height, leaves, shoots, appearance of flowering at plants aged two years. Culture of Aloe arborescens Mill. in pot, can be practiced all year, just in conditions of protected areas. This culture, realized in the purpose for obtain decorative plants, is a valuable activity of horticulture.

  20. Boxer crabs induce asexual reproduction of their associated sea anemones by splitting and intraspecific theft

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    Yisrael Schnytzer

    2017-01-01

    Full Text Available Crabs of the genus Lybia have the remarkable habit of holding a sea anemone in each of their claws. This partnership appears to be obligate, at least on the part of the crab. The present study focuses on Lybia leptochelis from the Red Sea holding anemones of the genus Alicia (family Aliciidae. These anemones have not been found free living, only in association with L. leptochelis. In an attempt to understand how the crabs acquire them, we conducted a series of behavioral experiments and molecular analyses. Laboratory observations showed that the removal of one anemone from a crab induces a “splitting” behavior, whereby the crab tears the remaining anemone into two similar parts, resulting in a complete anemone in each claw after regeneration. Furthermore, when two crabs, one holding anemones and one lacking them, are confronted, the crabs fight, almost always leading to the “theft” of a complete anemone or anemone fragment by the crab without them. Following this, crabs “split” their lone anemone into two. Individuals of Alicia sp. removed from freshly collected L. leptochelis were used for DNA analysis. By employing AFLP (Fluorescence Amplified Fragments Length Polymorphism it was shown that each pair of anemones from a given crab is genetically identical. Furthermore, there is genetic identity between most pairs of anemone held by different crabs, with the others showing slight genetic differences. This is a unique case in which one animal induces asexual reproduction of another, consequently also affecting its genetic diversity.

  1. Cancer and blood coagulation.

    Science.gov (United States)

    Boccaccio, C; Medico, E

    2006-05-01

    In human patients, blood coagulation disorders often associate with cancer, even in its early stages. Recently, in vitro and in vivo experimental models have shown that oncogene expression, or inactivation of tumour suppressor genes, upregulate genes that control blood coagulation. These studies suggest that activation of blood clotting, leading to peritumoral fibrin deposition, is instrumental in cancer development. Fibrin can indeed build up a provisional matrix, supporting the invasive growth of neoplastic tissues and blood vessels. Interference with blood coagulation can thus be considered as part of a multifaceted therapeutic approach to cancer.

  2. Activity of antioxidative defense enzymes in the blood of patients with liver echinococcosis

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    Lilić Aleksandar

    2007-01-01

    Full Text Available Background/Aim. Chronic echinococcocal disease is the parasite human disease caused by the penetration of larval (asexual stages of the canine tapeworm (Echinococcus granulosus in the liver of humans. After the penetration of the parasite, the host organism react by activating complement- depending immune response. The aim of this study was to elucidate the influence of larval form of Echinococcus granulosus in the liver on the activity of antioxidative defense enzymes in the blood of patients before and after the surgical intervention. Methods. We investigated the activity of antioxidative defense enzymes: copper/zinc containing superoxide dismutase (CuZn SOD, catalase (CAT, glutathione peroxidase (GSH-Px, glutathione reductase (GR and glutathione-S-transferase (GST in the blood of patients before and after the surgical intervention in respect to the controls, clinically healthy persons. Results. Our results showed that the activity of the GSH-Px was significantly decreased in the plasma of the patients with echinocococal disease before the surgery in respect to the controls. The activity of GST was significantly higher in the blood of the patients after the surgery in comparison to the controls. Conclusion. Chronic liver echinoccocal disease caused significant changes of some antioxidative defense enzymes, first of all Se-dependent enzyme GSH-Px, which could be a suitabile biomarker in the biochemical evaluation of the disease. This work represents a first comprehensive study of the activity of antioxidative defense enzymes in cronic liver echinococcocosis in the patients before and after the surgical intervention in respect to the clinically healthy persons.

  3. Asexual Reproduction Does Not Apparently Increase the Rate of Chromosomal Evolution: Karyotype Stability in Diploid and Triploid Clonal Hybrid Fish (Cobitis, Cypriniformes, Teleostei).

    Science.gov (United States)

    Majtánová, Zuzana; Choleva, Lukáš; Symonová, Radka; Ráb, Petr; Kotusz, Jan; Pekárik, Ladislav; Janko, Karel

    2016-01-01

    Interspecific hybridization, polyploidization and transitions from sexuality to asexuality considerably affect organismal genomes. Especially the last mentioned process has been assumed to play a significant role in the initiation of chromosomal rearrangements, causing increased rates of karyotype evolution. We used cytogenetic analysis and molecular dating of cladogenetic events to compare the rate of changes of chromosome morphology and karyotype in asexually and sexually reproducing counterparts in European spined loach fish (Cobitis). We studied metaphases of three sexually reproducing species and their diploid and polyploid hybrid clones of different age of origin. The material includes artificial F1 hybrid strains, representatives of lineage originated in Holocene epoch, and also individuals of an oldest known age to date (roughly 0.37 MYA). Thereafter we applied GISH technique as a marker to differentiate parental chromosomal sets in hybrids. Although the sexual species accumulated remarkable chromosomal rearrangements after their speciation, we observed no differences in chromosome numbers and/or morphology among karyotypes of asexual hybrids. These hybrids possess chromosome sets originating from respective parental species with no cytogenetically detectable recombinations, suggesting their integrity even in a long term. The switch to asexual reproduction thus did not provoke any significant acceleration of the rate of chromosomal evolution in Cobitis. Asexual animals described in other case studies reproduce ameiotically, while Cobitis hybrids described here produce eggs likely through modified meiosis. Therefore, our findings indicate that the effect of asexuality on the rate of chromosomal change may be context-dependent rather than universal and related to particular type of asexual reproduction.

  4. Asexual Reproduction Does Not Apparently Increase the Rate of Chromosomal Evolution: Karyotype Stability in Diploid and Triploid Clonal Hybrid Fish (Cobitis, Cypriniformes, Teleostei.

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    Zuzana Majtánová

    Full Text Available Interspecific hybridization, polyploidization and transitions from sexuality to asexuality considerably affect organismal genomes. Especially the last mentioned process has been assumed to play a significant role in the initiation of chromosomal rearrangements, causing increased rates of karyotype evolution. We used cytogenetic analysis and molecular dating of cladogenetic events to compare the rate of changes of chromosome morphology and karyotype in asexually and sexually reproducing counterparts in European spined loach fish (Cobitis. We studied metaphases of three sexually reproducing species and their diploid and polyploid hybrid clones of different age of origin. The material includes artificial F1 hybrid strains, representatives of lineage originated in Holocene epoch, and also individuals of an oldest known age to date (roughly 0.37 MYA. Thereafter we applied GISH technique as a marker to differentiate parental chromosomal sets in hybrids. Although the sexual species accumulated remarkable chromosomal rearrangements after their speciation, we observed no differences in chromosome numbers and/or morphology among karyotypes of asexual hybrids. These hybrids possess chromosome sets originating from respective parental species with no cytogenetically detectable recombinations, suggesting their integrity even in a long term. The switch to asexual reproduction thus did not provoke any significant acceleration of the rate of chromosomal evolution in Cobitis. Asexual animals described in other case studies reproduce ameiotically, while Cobitis hybrids described here produce eggs likely through modified meiosis. Therefore, our findings indicate that the effect of asexuality on the rate of chromosomal change may be context-dependent rather than universal and related to particular type of asexual reproduction.

  5. The Use of a New CellCollector to Isolate Circulating Tumor Cells from the Blood of Patients with Different Stages of Prostate Cancer and Clinical Outcomes - A Proof-of-Concept Study

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    Theil, Gerit; Fischer, Kersten; Weber, Ekkehard; Medek, Rita; Hoda, Raschid; Lücke, Klaus; Fornara, Paolo

    2016-01-01

    Background and Methods Circulating tumor cells (CTCs) constitute a useful approach for personalized medicine. Nevertheless, the isolation of these cells remains very challenging because they rarely circulate in the blood. Another current problem is the cancer-specific characterization of these cells, which requires a method that allows for the molecular and immunocytochemical profiling of all captured cells. The purpose of our proof of concept study was to investigate the use of a medical wire (CellCollector, GILUPI) to isolate CTCs in the blood of prostate cancer (PCa) patients, which allowed CTCs to be counted and molecularly characterized. Forty-three PCa patients in different stages and 11 control subjects were studied. Some randomized samples were used to detect tumor-associated transcripts, such as prostate-specific membrane antigen (PSMA), prostate-specific antigen (PSA) and epidermal growth factor receptor (EGFR), in the isolated CTCs. Results The mean CTC counts were 4.6 CTCs [range, 0–8] in patients with localized PCa, 16.8 CTCs [range, 10–25] in patients with locally advanced PCa, and 26.8 CTCs [range, 0–98] in patients with metastatic PCa. The median follow-up time was 24 months, and there was a significant difference in the cancer-specific survival rates. Patients with CTC counts under 5 CTCs lived significantly longer (p = 0.035) than patients with more than 5 CTCs. We also demonstrated that the captured CTCs could be molecularly characterized. We detected tumor-associated transcripts of EGFR and PSMA in patients with metastatic PCa in 42.8% and 14.3% of the analyzed samples, respectively. Conclusion Our results indicate that the sensitive isolation and molecular characterization of CTCs can be achieved ex vivo using the wire. Patients with more than 5 CTCs had a mortality risk that was 7.0 times greater that of those with fewer than 5 CTCs (hazard ratio 7.0 95%, CI 1.1–29.39). This proof of concept was required for the approval of the use of

  6. 2株间日疟原虫18S rDNA的克隆及其同源性分析%Cloning and homology analysis of blood stage 18S rDNA of two Plasmodium vivax isolates

    Institute of Scientific and Technical Information of China (English)

    高世同; 李晓恒; 耿艺介; 黄达娜; 谢旭; 梅树江; 张仁利

    2013-01-01

    目的 克隆间日疟原虫河南分离株与湖北分离株红内期18S rDNA,并进行同源性分析.方法 采用PCR方法从间日疟患者血样DNA中扩增间日疟原虫18S rDNA,纯化后与pGEM-Teasy质粒连接,转化大肠埃希氏菌JM109;阳性克隆质粒经双酶切鉴定后,进行序列测定,采用BLAST和MEGA4生物软件分析同源性. 结果 间日疟原虫18S rDNA扩增片段大小为998 bp;阳性克隆重组质粒经双酶切鉴定,与预期结果相符;序列测定结果显示,河南、湖北2分离株间日疟原虫18S rDNA序列完全相同,与GenBank中报道的12株间日疟原虫相同序列进行比对,其同源性均大于99%;用邻位连接法(neigh-bor-joining,NJ)和非加权组平均法(UPGMA)2种方法构建系统发生树发现,河南分离株、湖北分离株与间日疟原虫X13926.1株遗传距离小,同属一个分支.结论 克隆了间日疟原虫河南与湖北分离株红内期18S rDNA,该基因序列在不同地理株间遗传稳定.%Objective To clone and homology analyze the sequences of blood stage 18S rRNA-encoding gene fragment of two P.vivax isolates from Henan and Hubei provinces in China.Methods The 18S rDNA fragments were amplified by PCR from the DNA extracted from two P.vivax infection blood samples.After purification,the gene fragments were ligated with plasmid pGEM-Teasy to construct recombinant plasmids,and transformed into E.coli JM109.Positive clones were identified by double enzymes digestion methods.The sequences of inserted 18S rDNA fragments were finally determined and analyzed with BLAST and MEGA4 biological software.Results The amplified 18S rDNA fragments of two isolates were about 998 bp in length,and the 18S rDNA sequence of Henan isolate was same as that of Hubei isolate.As aligned with the corresponding sequences of twelve P.vivax strains deposited in the GenBank database,the indentity of nucleotides was more than 99% respectively.Based on the 18S rDNA sequence,phylogenetic analysis with

  7. Gene discovery in EST sequences from the wheat leaf rust fungus Puccinia triticina sexual spores, asexual spores and haustoria, compared to other rust and corn smut fungi

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    Wynhoven Brian

    2011-03-01

    Full Text Available Abstract Background Rust fungi are biotrophic basidiomycete plant pathogens that cause major diseases on plants and trees world-wide, affecting agriculture and forestry. Their biotrophic nature precludes many established molecular genetic manipulations and lines of research. The generation of genomic resources for these microbes is leading to novel insights into biology such as interactions with the hosts and guiding directions for breakthrough research in plant pathology. Results To support gene discovery and gene model verification in the genome of the wheat leaf rust fungus, Puccinia triticina (Pt, we have generated Expressed Sequence Tags (ESTs by sampling several life cycle stages. We focused on several spore stages and isolated haustorial structures from infected wheat, generating 17,684 ESTs. We produced sequences from both the sexual (pycniospores, aeciospores and teliospores and asexual (germinated urediniospores stages of the life cycle. From pycniospores and aeciospores, produced by infecting the alternate host, meadow rue (Thalictrum speciosissimum, 4,869 and 1,292 reads were generated, respectively. We generated 3,703 ESTs from teliospores produced on the senescent primary wheat host. Finally, we generated 6,817 reads from haustoria isolated from infected wheat as well as 1,003 sequences from germinated urediniospores. Along with 25,558 previously generated ESTs, we compiled a database of 13,328 non-redundant sequences (4,506 singlets and 8,822 contigs. Fungal genes were predicted using the EST version of the self-training GeneMarkS algorithm. To refine the EST database, we compared EST sequences by BLASTN to a set of 454 pyrosequencing-generated contigs and Sanger BAC-end sequences derived both from the Pt genome, and to ESTs and genome reads from wheat. A collection of 6,308 fungal genes was identified and compared to sequences of the cereal rusts, Puccinia graminis f. sp. tritici (Pgt and stripe rust, P. striiformis f. sp

  8. Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction.

    Science.gov (United States)

    Hansel, Colleen M; Zeiner, Carolyn A; Santelli, Cara M; Webb, Samuel M

    2012-07-31

    Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

  9. Mn(II) oxidation by an ascomycete fungus is linked to superoxide production during asexual reproduction

    Energy Technology Data Exchange (ETDEWEB)

    Hansel, C. M.; Zeiner, C. A.; Santelli, C. M.; Webb, S. M.

    2012-07-16

    Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-specific chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete filamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identification of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Finally, given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

  10. Asexual endophytes in a native grass: tradeoffs in mortality, growth, reproduction, and alkaloid production.

    Science.gov (United States)

    Faeth, Stanley H; Hayes, Cinnamon J; Gardner, Dale R

    2010-10-01

    Neotyphodium endophytes are asexual, seed-borne fungal symbionts that are thought to interact mutualistically with their grass hosts. Benefits include increased growth, reproduction, and resistance to herbivores via endophytic alkaloids. Although these benefits are well established in infected introduced, agronomic grasses, little is known about the cost and benefits of endophyte infection in native grass populations. These populations exist as mosaics of uninfected and infected plants, with the latter often comprised of plants that vary widely in alkaloid content. We tested the costs and benefits of endophyte infections with varying alkaloids in the native grass Achnatherum robustum (sleepygrass). We conducted a 4-year field experiment, where herbivory and water availability were controlled and survival, growth, and reproduction of three maternal plant genotypes [uninfected plants (E-), infected plants with high levels of ergot alkaloids (E+A+), and infected plants with no alkaloids (E+A-)] were monitored over three growing seasons. Generally, E+A+ plants had reduced growth over the three growing seasons and lower seed production than E- or E+A- plants, suggesting a cost of alkaloid production. The reduction in vegetative biomass in E+A+ plants was most pronounced under supplemented water, contrary to the prediction that additional resources would offset the cost of alkaloid production. Also, E+A+ plants showed no advantage in growth, seed production, or reproductive effort under full herbivory relative to E- or E+A- grasses, contrary to the predictions of the defensive mutualism hypothesis. However, E+A+ plants had higher overwintering survival than E+A- plants in early plant ontogeny, suggesting that alkaloids associated with infection may protect against below ground herbivory or harsh winter conditions. Our results suggest that the mosaic of E-, E+A+, and E+A- plants observed in nature may result from varying biotic and abiotic selective factors that maintain

  11. The planarian P2X homolog in the regulation of asexual reproduction.

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    Sakurai, Toshihide; Lee, Hayoung; Kashima, Makoto; Saito, Yumi; Hayashi, Tetsutaro; Kudome-Takamatsu, Tomomi; Nishimura, Osamu; Agata, Kiyokazu; Shibata, Norito

    2012-01-01

    The growth in size of freshwater planarians in response to nutrient intake is limited by the eventual separation of tail and body fragments in a process called fission. The resulting tail fragment regenerates the entire body as an artificially amputated tail fragment would do, and the body fragment regenerates a tail, resulting in two whole planarians. This regenerative ability is supported by pluripotent somatic stem cells, called neoblasts, which are distributed throughout almost the entire body of the planarian. Neoblasts are the only planarian cells with the ability to continuously proliferate and give rise to all types of cells during regeneration, asexual reproduction, homeostasis, and growth. In order to investigate the molecular characteristics of neoblasts, we conducted an extensive search for neoblast-specific genes using the High Coverage Expression Profiling (HiCEP) method, and tested the function of the resulting candidates by RNAi. Disruption of the expression of one candidate gene, DjP2X-A (Dugesia japonica membrane protein P2X homologue), resulted in a unique phenotype. DjP2X-A RNAi leads to an increase of fission events upon feeding. We confirmed by immunohistochemistry that DjP2X-A is a membrane protein, and elucidated its role in regulating neoblast proliferation, thereby explaining its unique phenotype. We found that DjP2X-A decreases the burst of neoblast proliferation that normally occurs after feeding. We also found that DjP2X-A is required for normal proliferation in starved animals. We propose that DjP2X-A modulates stem cell proliferation in response to the nutritional condition.

  12. Truncation of LEAFY COTYLEDON1 protein is required for asexual reproduction in Kalanchoë daigremontiana.

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    Garcês, Helena M P; Koenig, Daniel; Townsley, Brad T; Kim, Minsung; Sinha, Neelima R

    2014-05-01

    Kalanchoë daigremontiana reproduces asexually by generating numerous plantlets on its leaf margins. The formation of plantlets requires the somatic initiation of organogenic and embryogenic developmental programs in the leaves. However, unlike normal embryogenesis in seeds, leaf somatic embryogenesis bypasses seed dormancy to form viable plantlets. In Arabidopsis (Arabidopsis thaliana), seed dormancy and embryogenesis are initiated by the transcription factor LEAFY COTYLEDON1 (LEC1). The K. daigremontiana ortholog of LEC1 is expressed during leaf somatic embryo development. However, KdLEC1 encodes for a LEC1-type protein that has a unique B domain, with 11 unique amino acids and a premature stop codon. Moreover, the truncated KdLEC1 protein is not functional in Arabidopsis. Here, we show that K. daigremontiana transgenic plants expressing a functional, chimeric KdLEC1 gene under the control of Arabidopsis LEC1 promoter caused several developmental defects to leaf somatic embryos, including seed dormancy characteristics. The dormant plantlets also behaved as typical dormant seeds. Transgenic plantlets accumulated oil bodies and responded to the abscisic acid biosynthesis inhibitor fluridone, which broke somatic-embryo dormancy and promoted their normal development. Our results indicate that having a mutated form of LEC1 gene in K. daigremontiana is essential to bypass dormancy in the leaf embryos and generate viable plantlets, suggesting that the loss of a functional LEC1 promotes viviparous leaf somatic embryos and thus enhances vegetative propagation in K. daigremontiana. Mutations resulting in truncated LEC1 proteins may have been of a selective advantage in creating somatic propagules, because such mutations occurred independently in several Kalanchoë species, which form plantlets constitutively.

  13. Comparison of three replication strategies in complex multicellular organisms: Asexual replication, sexual replication with identical gametes, and sexual replication with distinct sperm and egg gametes

    Science.gov (United States)

    Tannenbaum, Emmanuel

    2008-01-01

    This paper studies the mutation-selection balance in three simplified replication models. The first model considers a population of organisms replicating via the production of asexual spores. The second model considers a sexually replicating population that produces identical gametes. The third model considers a sexually replicating population that produces distinct sperm and egg gametes. All models assume diploid organisms whose genomes consist of two chromosomes, each of which is taken to be functional if equal to some master sequence, and defective otherwise. In the asexual population, the asexual diploid spores develop directly into adult organisms. In the sexual populations, the haploid gametes enter a haploid pool, where they may fuse with other haploids. The resulting immature diploid organisms then proceed to develop into mature organisms. Based on an analysis of all three models, we find that, as organism size increases, a sexually replicating population can only outcompete an asexually replicating population if the adult organisms produce distinct sperm and egg gametes. A sexual replication strategy that is based on the production of large numbers of sperm cells to fertilize a small number of eggs is found to be necessary in order to maintain a sufficiently low cost for sex for the strategy to be selected for over a purely asexual strategy. We discuss the usefulness of this model in understanding the evolution and maintenance of sexual replication as the preferred replication strategy in complex, multicellular organisms.

  14. Blood groups systems

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    Ranadhir Mitra

    2014-01-01

    Full Text Available International Society of Blood Transfusion has recently recognized 33 blood group systems. Apart from ABO and Rhesus system, many other types of antigens have been noticed on the red cell membranes. Blood grouping and cross-matching is one of the few important tests that the anaesthesiologist orders during perioperative period. Hence, a proper understanding of the blood group system, their clinical significance, typing and cross-matching tests, and current perspective are of paramount importance to prevent transfusion-related complications. Nonetheless, the knowledge on blood group system is necessary to approach blood group-linked diseases which are still at the stage of research. This review addresses all these aspects of the blood groups system.

  15. Cross-stage immunity for malaria vaccine development.

    Science.gov (United States)

    Nahrendorf, Wiebke; Scholzen, Anja; Sauerwein, Robert W; Langhorne, Jean

    2015-12-22

    A vaccine against malaria is urgently needed for control and eventual eradication. Different approaches are pursued to induce either sterile immunity directed against pre-erythrocytic parasites or to mimic naturally acquired immunity by controlling blood-stage parasite densities and disease severity. Pre-erythrocytic and blood-stage malaria vaccines are often seen as opposing tactics, but it is likely that they have to be combined into a multi-stage malaria vaccine to be optimally safe and effective. Since many antigenic targets are shared between liver- and blood-stage parasites, malaria vaccines have the potential to elicit cross-stage protection with immune mechanisms against both stages complementing and enhancing each other. Here we discuss evidence from pre-erythrocytic and blood-stage subunit and whole parasite vaccination approaches that show that protection against malaria is not necessarily stage-specific. Parasites arresting at late liver-stages especially, can induce powerful blood-stage immunity, and similarly exposure to blood-stage parasites can afford pre-erythrocytic immunity. The incorporation of a blood-stage component into a multi-stage malaria vaccine would hence not only combat breakthrough infections in the blood should the pre-erythrocytic component fail to induce sterile protection, but would also actively enhance the pre-erythrocytic potency of this vaccine. We therefore advocate that future studies should concentrate on the identification of cross-stage protective malaria antigens, which can empower multi-stage malaria vaccine development.

  16. The putative protein methyltransferase LAE1 of Trichoderma atroviride is a key regulator of asexual development and mycoparasitism.

    Directory of Open Access Journals (Sweden)

    Razieh Karimi Aghcheh

    Full Text Available In Ascomycota the protein methyltransferase LaeA is a global regulator that affects the expression of secondary metabolite gene clusters, and controls sexual and asexual development. The common mycoparasitic fungus Trichoderma atroviride is one of the most widely studied agents of biological control of plant-pathogenic fungi that also serves as a model for the research on regulation of asexual sporulation (conidiation by environmental stimuli such as light and/or mechanical injury. In order to learn the possible involvement of LAE1 in these two traits, we assessed the effect of deletion and overexpression of lae1 gene on conidiation and mycoparasitic interaction. In the presence of light, conidiation was 50% decreased in a Δ lae1 and 30-50% increased in lae1-overexpressing (OElae1 strains. In darkness, Δ lae1 strains did not sporulate, and the OElae1 strains produced as much spores as the parent strain. Loss-of-function of lae1 also abolished sporulation triggered by mechanical injury of the mycelia. Deletion of lae1 also increased the sensitivity of T. atroviride to oxidative stress, abolished its ability to defend against other fungi and led to a loss of mycoparasitic behaviour, whereas the OElae1 strains displayed enhanced mycoparasitic vigor. The loss of mycoparasitic activity in the Δ lae1 strain correlated with a significant underexpressionn of several genes normally upregulated during mycoparasitic interaction (proteases, GH16 ß-glucanases, polyketide synthases and small cystein-rich secreted proteins, which in turn was reflected in the partial reduction of formation of fungicidal water soluble metabolites and volatile compounds. Our study shows T. atroviride LAE1 is essential for asexual reproduction in the dark and for defense and parasitism on other fungi.

  17. Resilience of Zostera muelleri seagrass to small-scale disturbances: the relative importance of asexual versus sexual recovery.

    Science.gov (United States)

    Macreadie, Peter I; York, Paul H; Sherman, Craig Dh

    2014-02-01

    Resilience is the ability of an ecosystem to recover from disturbance without loss of essential function. Seagrass ecosystems are key marine and estuarine habitats that are under threat from a variety of natural and anthropogenic disturbances. The ability of these ecosystems to recovery from disturbance will to a large extent depend on the internsity and scale of the disturbance, and the relative importance of sexual versus asexual reproduction within populations. Here, we investigated the resilience of Zostera muelleri seagrass (Syn. Zostera capricorni) to small-scale disturbances at four locations in Lake Macquarie - Australia's largest coastal lake - and monitored recovery over a 65-week period. Resilience of Z. muelleri varied significantly with disturbance intensity; Z. muelleri recovered rapidly (within 2 weeks) from low-intensity disturbance (shoot loss), and rates of recovery appeared related to initial shoot length. Recovery via rhizome encroachment (asexual regeneration) from high-intensity disturbance (loss of entire plant) varied among locations, ranging from 18-35 weeks, whereas the ability to recover was apparently lost (at least within the time frame of this study) when recovery depended on sexual regeneration, suggesting that seeds do not provide a mechanism of recovery against intense small-scale disturbances. The lack of sexual recruits into disturbed sites is surprising as our initial surveys of genotypic diversity (using nine polymorphic microsatellite loci) at these location indicate that populations are maintained by a mix of sexual and asexual reproduction (genotypic diversity [R] varied from 0.24 to 0.44), and populations consisted of a mosaic of genotypes with on average 3.6 unique multilocus genotypes per 300 mm diameter plot. We therefore conclude that Z. muelleri populations within Lake Macquarie rely on clonal growth to recover from small-scale disturbances and that ongoing sexual recruitment by seeds into established seagrass beds

  18. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...... localities of tensions between matter and the immaterial, the practical and the ideal, and subject and object. In the colloquial language there can, moreover, often seem to be something authentic or genuine about atmosphere, juxtaposing it to staging, which is implied to be something simulated or artificial....... This introduction seeks to outline how a number of scholars have addressed the relationship between staged atmospheres and experience, and thus highlight both the philosophical, social and political aspects of atmospheres...

  19. Female parthenogenetic apomixis and androsporogenetic parthenogenesis in embryonal cells of Araucaria angustifolia: interpolation of progenesis and asexual heterospory in an artificial sporangium.

    Science.gov (United States)

    Durzan, Don J

    2012-09-01

    Cell fate, development timing and occurrence of reproductive versus apomictic development in gymnosperms are shown to be influenced by culture conditions in vitro. In this study, female parthenogenetic apomixis (fPA), androsporogenetic parthenogenesis (mAP) and progenesis were demonstrated using embryonal initials of Araucaria angustifolia in scaled-up cell suspensions passing through a single-cell bottleneck in darkness and in an artificial sporangium (AS). Expression was based on defined nutrition, hormones and feedforward-adaptive feedback process controls at 23-25 °C and in darkness. In fPA, the nucleus of an embryonal initial undergoes endomitosis and amitosis, forming a diploid egg-equivalent and an apoptotic ventral canal nucleus in a transdifferentiated archegonial tube. Discharge of egg-equivalent cells as parthenospores and their dispersal into the aqueous culture medium were followed by free-nuclear conifer-type proembryogenesis. This replaced the plesiomorphic and central features of proembryogenesis in Araucariaceae. Protoplasmic fusions of embryonal initials were used to reconstruct heterokaryotic expressions of fPA in multiwell plates. In mAP, restitutional meiosis (automixis) was responsible for androsporogenesis and the discharge of monads, dyads, tetrads and polyads. In a display of progenesis, reproductive development was brought to an earlier ontogenetic stage and expressed by embryonal initials. Colchicine increased polyploidy, but androspore formation became aberrant and fragmented. Aberrant automixis led to the formation of chromosomal bouquets, which contributed to genomic silencing in embryonal initials, cytomixis and the formation of pycnotic micronucleated cells. Dispersal of female and male parthenospores displayed heteromorphic asexual heterospory in an aqueous environment.

  20. Blood smear

    Science.gov (United States)

    ... some red blood cells shaped like spheres ( hereditary spherocytosis ) Increased breakdown of RBCs Presence of RBCs with ... normal Red blood cells, elliptocytosis Red blood cells, spherocytosis Acute lymphocytic leukemia - photomicrograph Red blood cells, multiple ...

  1. Blood culture

    Science.gov (United States)

    Culture - blood ... A blood sample is needed . The site where blood will be drawn is first cleaned with an antiseptic such ... organism from the skin getting into (contaminating) the blood sample and causing a false-positive result (see ...

  2. Blood Thinners

    Science.gov (United States)

    If you have some kinds of heart or blood vessel disease, or if you have poor blood flow to your brain, your doctor may recommend that you take a blood thinner. Blood thinners reduce the risk of heart ...

  3. Blood transfusions

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000431.htm Blood transfusions To use the sharing features on this ... several sources of blood which are described below. Blood From the Public (Volunteer Blood Donation) The most ...

  4. Mutation accumulation and fitness effects in hybridogenetic populations: a comparison to sexual and asexual systems

    Directory of Open Access Journals (Sweden)

    Bagheri Homayoun C

    2007-05-01

    Full Text Available Abstract Background Female only unisexual vertebrates that reproduce by hybridogenesis show an unusual genetic composition. They are of hybrid origin but show no recombination between the genomes of their parental species. Instead, the paternal genome is discarded from the germline prior to meiosis, and gametes (eggs only contain solely unrecombined maternal genomes. Hence hybridogens only transmit maternally inherited mutations. Hybridity is restored each generation by backcrossing with males of the sexual parental species whose genome was eliminated. In contrast, recombining sexual species propagate an intermixed pool of mutations derived from the maternal and paternal parts of the genome. If mutation rates are lower in female gametes than males, it raises the possibility for lower mutation accumulation in a hybridogenetic population, and consequently, higher population fitness than its sexual counterpart. Results We show through Monte-Carlo simulations that at higher male to female mutation ratios, and sufficiently large population sizes, hybridogenetic populations can carry a lower mutation load than sexual species. This effect is more pronounced with synergistic forms of epistasis. Mutations accumulate faster on the sexual part of the genome, and with the purifying effects of epistasis, it makes it more difficult for mutations to be transmitted on the clonal part of the genome. In smaller populations, the same mechanism reduces the speed of Muller's Ratchet and the number of fixed mutations compared to similar asexual species. Conclusion Since mutation accumulation can be less pronounced in hybridogenetic populations, the question arises why hybridogenetic organisms are so scarce compared to sexual species. In considering this, it is likely that comparison of population fitnesses is not sufficient. Despite competition with the sexual parental species, hybrid populations are dependent on the maintenance of – and contact with – their

  5. Sex in an uncertain world: environmental stochasticity helps restore competitive balance between sexually and asexually reproducing populations.

    Science.gov (United States)

    Park, A W; Vandekerkhove, J; Michalakis, Y

    2014-08-01

    Like many organisms, individuals of the freshwater ostracod species Eucypris virens exhibit either obligate sexual or asexual reproductive modes. Both types of individual routinely co-occur, including in the same temporary freshwater pond (their natural habitat in which they undergo seasonal diapause). Given the well-known two-fold cost of sex, this begs the question of how sexually reproducing individuals are able to coexist with their asexual counterparts in spite of such overwhelming costs. Environmental stochasticity in the form of 'false dawn' inundations (where the first hydration is ephemeral and causes loss of early hatching individuals) may provide an advantage to the sexual subpopulation, which shows greater variation in hatching times following inundation. We explore the potential role of environmental stochasticity in this system using life-history data analysis, climate data, and matrix projection models. In the absence of environmental stochasticity, the population growth rate is significantly lower in sexual subpopulations. Climate data reveal that 'false dawn' inundations are common. Using matrix projection modelling with and without environmental stochasticity, we demonstrate that this phenomenon can restore appreciable balance to the system, in terms of population growth rates. This provides support for the role of environmental stochasticity in helping to explain the maintenance of sex and the occurrence of geographical parthenogenesis.

  6. Polymorphism and methylation patterns in Agave tequilana Weber var. 'Azul' plants propagated asexually by three different methods.

    Science.gov (United States)

    Díaz-Martínez, Miriam; Nava-Cedillo, Alejandro; Guzmán-López, José Alfredo; Escobar-Guzmán, Rocío; Simpson, June

    2012-04-01

    Genetic variation in three forms of asexually propagated Agave tequilana Weber var. 'Azul' plants namely offsets, bulbils and in vitro cultured individuals was studied by AFLP analysis. Low levels of variation were observed between mother plants and offsets and a higher level between mother plant and bulbils. Families obtained from commercial plantations showed lower levels of variation in comparison to families grown as ornamentals. No variation was observed between the original explant and four generations of in vitro cultured plants. Epigenetic variation was also studied by analyzing changes in methylation patterns between mother plants and offspring in each form of asexual reproduction. Offsets and bulbils showed an overall decrease in methylation whereas in vitro cultured plants showed patterns specific to each generation: Generations 1 and 4 showed overall demethylation whereas Generations 2 and 3 showed increased methylation. Analysis of ESTs associated with transposable elements revealed higher proportions of ESTs from Ty1-copia-like, Gypsy and CACTA transposable elements in cDNA libraries obtained from pluripotent tissue suggesting a possible correlation between methylation patterns, expression of transposable element associated genes and somaclonal variation.

  7. PFRU, a single dominant locus regulates the balance between sexual and asexual plant reproduction in cultivated strawberry.

    Science.gov (United States)

    Gaston, Amèlia; Perrotte, Justine; Lerceteau-Köhler, Estelle; Rousseau-Gueutin, Mathieu; Petit, Aurélie; Hernould, Michel; Rothan, Christophe; Denoyes, Béatrice

    2013-04-01

    Strawberry (Fragaria sp.) stands as an interesting model for studying flowering behaviour and its relationship with asexual plant reproduction in polycarpic perennial plants. Strawberry produces both inflorescences and stolons (also called runners), which are lateral stems growing at the soil surface and producing new clone plants. In this study, the flowering and runnering behaviour of two cultivated octoploid strawberry (Fragaria × ananassa Duch., 2n = 8× = 56) genotypes, a seasonal flowering genotype CF1116 and a perpetual flowering genotype Capitola, were studied along the growing season. The genetic bases of the perpetual flowering and runnering traits were investigated further using a pseudo full-sibling F1 population issued from a cross between these two genotypes. The results showed that a single major quantitative trait locus (QTL) named FaPFRU controlled both traits in the cultivated octoploid strawberry. This locus was not orthologous to the loci affecting perpetual flowering (SFL) and runnering (R) in Fragaria vesca, therefore suggesting different genetic control of perpetual flowering and runnering in the diploid and octoploid Fragaria spp. Furthermore, the FaPFRU QTL displayed opposite effects on flowering (positive effect) and on runnering (negative effect), indicating that both traits share common physiological control. These results suggest that this locus plays a major role in strawberry plant fitness by controlling the balance between sexual and asexual plant reproduction.

  8. Size Matters!. Birth Size and a Size-Independent Stochastic Term Determine Asexual Reproduction Dynamics in Freshwater Planarians

    Science.gov (United States)

    Thomas, Michael A.; Quinodoz, Sofia; Schötz, Eva-Maria

    2012-09-01

    Asexual reproduction by division in higher organisms is rare, because a prerequisite is the ability to regenerate an entire organism from a piece of the original body. Freshwater planarians are one of the few animals that can reproduce this way, but little is known about the regulation of their reproduction cycles or strategies. We have previously shown that a planarian's reproduction strategy is randomized to include fragmentations, producing multiple offspring, as well as binary fissions, and can be partially explained by a maximum relative entropy principle. In this study we attempt to decompose the factors controlling their reproduction cycle. Based on recent studies on the cell cycle of budding yeast, which suggest that molecular noise in gene expression and cell size at birth together control cell cycle variability, we investigated whether the variability in planarian reproduction waiting times could be similarly regulated. We find that such a model can indeed explain the observed distribution of waiting times between birth and next reproductive event, suggesting that birth size and a stochastic noise term govern the reproduction dynamics of asexual planarians.

  9. Comparative transcriptional analysis of asexual and sexual morphs reveals possible mechanisms in reproductive polyphenism of the cotton aphid.

    Directory of Open Access Journals (Sweden)

    Li-Jun Liu

    Full Text Available Aphids, the destructive insect pests in the agriculture, horticulture and forestry, are capable of reproducing asexually and sexually upon environmental change. However, the molecular basis of aphid reproductive mode switch remains an enigma. Here we report a comparative analysis of differential gene expression profiling among parthenogenetic females, gynoparae and sexual females of the cotton aphid Aphis gossypii, using the RNA-seq approach with next-generation sequencing platforms, followed by RT-qPCR. At the cutoff criteria of fold change ≥2 and P<0.01, we identified 741 up- and 879 down-regulated genes in gynoparae versus parthenogenetic females, 2,101 up- and 2,210 down-regulated genes in sexual females compared to gynoparae, and 1,614 up- and 2,238 down-regulated genes in sexual females relative to parthenogenetic females. Gene ontology category and KEGG pathway analysis suggest the involvement of differentially expressed genes in multiple cellular signaling pathways into the reproductive mode transition, including phototransduction, cuticle composition, progesterone-mediated oocyte maturation and endocrine regulation. This study forms a basis for deciphering the molecular mechanisms underlying the shift from asexual to sexual reproduction in the cotton aphid. It also provides valuable resources for future studies on this host-alternating aphid species, and the insight into the understanding of reproductive mode plasticity in different aphid species.

  10. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    In recent years, the social sciences have taken a “mobilities turn.” There has been a developing realisation that mobilities do not “just happen.” Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed...... that mobility is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments......, the book asks: what are the physical, social, technical, and cultural conditions to the staging of contemporary urban mobilities?...

  11. Blood Donation

    Science.gov (United States)

    Tests and Procedures Blood donation By Mayo Clinic Staff Blood donation is a voluntary procedure. You agree to have blood drawn so that it can ... have a disease that requires blood components. Blood donation makes all of this possible. There are several ...

  12. Sex pheromone of a coccoid insect with sexual and asexual lineages: fate of an ancestrally essential sexual signal in parthenogenetic females.

    Science.gov (United States)

    Tabata, Jun; Ichiki, Ryoko T; Moromizato, Chie; Mori, Kenji

    2017-03-01

    Sex pheromones play a central role in intersexual communication for reproduction in many organisms. Particularly in insects, reproductive isolation that leads to speciation is often achieved by shifts of pheromone chemistries. However, the divergence and evolution of pheromones remain largely unknown. This study reveals a unique evolutionary consequence for terpenoid pheromones in coccoid insects. Coccoids, such as mealybugs, show clear sexual dimorphism: males are dwarf and short-lived, whereas females are wingless and almost immobile. Female pheromones are therefore indispensable for males to navigate for sexual reproduction, but some females can reproduce asexually. Interestingly, a derived asexual lineage that reproduces by parthenogenesis coexists with its ancestral lineage that reproduces sexually in a population of the pineapple mealybug, Dysmicoccus brevipes Here, we isolated, characterized and synthesized a novel monoterpene, (-)-(anti-1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde, as a pheromone of the sexual females of Dbrevipes This monoterpene aldehyde, with an irregular linkage of isoprene units, is notable, because all mealybug pheromones previously reported are carboxylic esters of terpenols. This compound was, however, never produced by the asexual females. As a consequence of acquiring parthenogenetic reproduction, the asexual females appear to have abandoned the production of the sex pheromone, which had been essential to attracting males in their ancestors.

  13. The role of sexual vs. asexual recruitment of Artemisia wudanica in transition zone habitats between inter-dune lowlands and active dunes in Inner Mongolia, China

    Science.gov (United States)

    Wang, Yongcui; Alberto, Busso Carlos; Jiang, Deming; Ala, Musa; Li, Xuehua; Zhou, Quanlai; Lin, Jixiang; Ren, Guohua; Jia, Lian

    2016-04-01

    Artemisia wudanica is an endemic, perennial, pioneering psammophyte species in the sand dune ecosystems of western Horqin Sand Land in northern China. However, no studies have addressed how sexual and asexual reproduction modes of A. wudanica perform at the transitional zones between active dune inter-dune lowlands and active dunes. In early spring, quadrats were randomly set up in the study area to monitor surviving seedling and/or ramet density and frequency coming from sexual/asexual reproduction of A. wudanica. Iron sticks were inserted near each quadrat to determine wind erosion intensity (WE). Additionally, soil samples were collected nearby each quadrat to test for soil moisture (SM), organic matter (OM) and pH. Surviving seedlings of A. wudanica showed an inverse response in comparison with ramets to SM, OM and WE. Soil moisture showed the most positive effect, and WE the negative effect, on surviving, sexual reproduction seedlings. Contrarily, WE had the most positive effect, and SM the negative effect, on asexual reproduction ramets. This suggests that increases in SM and decreases in WE should benefit recruitment of A. wudanica seedlings. On the contrary, ramets coming from asexual reproduction showed a different response to environmental factors in transition zone habitats. While SM was not a key constraint for the survival of seedlings, they showed a better, positive response to wind erosion environments. Overall, various study environmental parameters could be improved to foster A. wudanica invasion and settlement in the plant community through different reproductive modes, thereby promoting vegetation restoration and rehabilitation.

  14. Variation in the strength of male mate choice allows long-term coexistence of sperm-dependent asexuals and their sexual hosts.

    Science.gov (United States)

    Mee, Jonathan A; Otto, Sarah P

    2010-10-01

    In several asexual taxa, reproduction requires mating with related sexual species to stimulate egg development, even though genetic material is not incorporated from the sexuals (gynogenesis). In cases in which gynogens do not invest in male function, they can potentially have a twofold competitive advantage over sexuals because the asexuals avoid the cost of producing males. If unmitigated, however, the competitive success of the asexuals would ultimately lead to their own demise, following the extinction of the sexual species that stimulate egg development. We have studied a model of mate choice among sexual individuals and asexual gynogens, where males of the sexual species preferentially mate with sexual females over gynogenetic females, to determine if such mating preferences can stably maintain both gynogenetic and sexual individuals within a community. Our model shows that stable coexistence of gynogens and their sexual hosts can occur when there is variation among males in the degree of preference for mating with sexual females and when pickier males pay a higher cost of preference.

  15. Donating Blood

    Science.gov (United States)

    ... can't get an infection or disease from giving blood. The needles and other equipment used are sterile ... part of blood (plasma) within 72 hours after giving blood. It generally takes about 4–8 weeks to ...

  16. The level of plasma lipid in different blood glucose control stages of type 2 diabetics%血糖控制不同阶段2型糖尿病患者的血脂水平

    Institute of Scientific and Technical Information of China (English)

    季方圆; 逄曙光; 田玉玲

    2015-01-01

    目的:探讨2型糖尿病(T2DM)患者血糖控制不同阶段的血脂水平特点。方法对361例T2DM住院患者(根据既往病史及血糖水平分为血糖控制达标组、血糖控制较差组)及239例健康体检对照组分别测糖化血红蛋白(HbA1c)、血清甘油三酯(TG)、总胆固醇(TCH)、高密度脂蛋白(HDL-C)及低密度脂蛋白(LDL-C)水平,比较血糖控制达标组、血糖控制较差组及对照组间血脂水平。结果与正常对照组比较,T2DM组TG、TCH、LDL-C水平明显升高,HDL-C水平降低;血糖控制达标组TCH、HDL-C和 LDL-C水平无显著差异( P>0.05);而血糖控制较差组 TCH和 LDL-C水平与正常对照组比较显著升高,HDL-C 水平降低(P<0.05);所有 DM 组的 TG 水平均与正常对照组有显著差异(P<0.05);TG、TCH、HDL-C 和LDL-C均与HbA1c具有平行关系(P<0.05),TG、TCH和LDL-C随HbA1c升高而升高,HDL-C则相反。结论 T2DM 血糖控制情况与血脂水平具有一定的关联性,血糖控制达标有助于TCH和LDL-C的降低及HDL-C的提高,对TG异常亦有所改善。%Objective To investigate the characteristic of plasma lipid in different blood glucose control stages of type 2 diabetics (T2DM).Methods 390T2DMpatientsweredividedintowell-controlledandpoorly-controlledgroupsintermsofmedicalhistoryandblood glucose level,and 210 healthy samples were examined the levels of Hemoglobin A1C(HbA1c),serum triglyceride(TG),total cholesterol (TCH),high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C),respectively.Results After elimi-nating other factors on their influence of plasma lipid ,compared with those of normal control group ,the levels of TCH ,HDL-C and LDL-C had no significant differences in the well-controlled group ( P>0.05 ) ;while the levels of TCH and LDL-C were significantly higher and the level of HDL-C was

  17. [Effect of weak and superweak magnetic fields on intensity and asexual reproduction of the planarian Dugesia tigrina].

    Science.gov (United States)

    Novikov, V V; Sheĭman, I M; Fesenko, E E

    2002-01-01

    It was shown that the exposure to combined weak and extraweak magnetic fields (permanent component 42 microT; variable component of an amplitude of 100 nT, frequency 1-60 Hz) increases the intensity of asexual propagation of planarians Dugesia tigrina. The effect of combined magnetic fields is most pronounced at frequencies of 1, 3.7, and 32 Hz. The presence of concomitant technogeneous fields (50 Hz, 30 nT) does not markedly influence the effects of weak magnetic fields with a small variable component. Upon realization of effects of weak magnetic fields, their both components are of great importance; the absence of one (permanent) component changes the sing of the effect to the opposite. The transfer of the effect to planarians through water pretreated with magnetic fields probably indicates that aqueous medium is involved in the realization of biological effects of weak magnetic fields.

  18. Asexual genome evolution in the apomictic Ranunculus auricomus complex: examining the effects of hybridization and mutation accumulation.

    Science.gov (United States)

    Pellino, Marco; Hojsgaard, Diego; Schmutzer, Thomas; Scholz, Uwe; Hörandl, Elvira; Vogel, Heiko; Sharbel, Timothy F

    2013-12-01

    Asexual lineages are thought to be prone to extinction because of deleterious mutation accumulation (Muller's ratchet). Here, we analyse genomic effects of hybridity, polyploidy and allelic divergence in apomictic plants, and identify loci under divergent selection among sexual/apomictic lineages. RNAseq was used to sequence the flower-specific transcriptomes of five genotypes of the Ranunculus auricomus complex, representing three sexual and two apomictic reproductive biotypes. The five sequence libraries were pooled and de novo assembly performed, and the resultant assembly was used as a backbone for a subsequent alignment of each separate library. High-quality single-nucleotide (SNP) and insertion-deletion (indel) polymorphisms were mined from each library. Annotated genes for which open reading frames (ORF) could be determined were analysed for signatures of divergent versus stabilizing selection. A comparison between all genotypes supports the hypothesis of Pleistocene hybrid origin of both apomictic genotypes from R. carpaticola and R. cassubicifolius, with subsequent allelic divergence of apomictic lineages (Meselson effect). Pairwise comparisons of nonsynonymous (dN) to synonymous (dS) substitution rate ratios between apomictic and sexual genotypes for 1231 genes demonstrated similar distributions for all comparisons, although 324 genes demonstrated outlier (i.e. elevated) dN/dS ratios. Gene ontology analyses of these outliers revealed significant enrichment of genes associated with reproduction including meiosis and gametogenesis, following predictions of divergent selection between sexual and apomictic reproduction, although no significant signal of genome-wide mutation accumulation could be identified. The results suggest that gene function should be considered in order to understand effects of mutation accumulation in asexual lineages.

  19. F-statistics under alternation of sexual and asexual reproduction: a model and data from schistosomes (platyhelminth parasites).

    Science.gov (United States)

    Prugnolle, Franck; Roze, Denis; Théron, André; DE Meeûs, Thierry

    2005-04-01

    Accurate inferences on population genetics data require a sound underlying theoretical null model. Nearly nothing is known about the gene dynamics of organisms with complex life cycles precluding any biological interpretation of population genetics parameters. In this article, we used an infinite island model to derive the expectations of those parameters for the life cycle of a dioecious organism obligatorily alternating sexual and asexual reproductions as it is the case for schistosomes (plathyhelminth parasites). This model allowed us to investigate the effects of the degree of mixing among individuals coming from different subpopulations at each new generation (represented in the model by the migration rates before and after clonal reproductions) and the variance in the reproductive success of individuals during the clonal phase. We also consider the effects of different migration rates and degrees of clonal reproductive skew between male and female individuals. Results show that the variance in the reproductive success of clones is very important in shaping the distribution of the genetic variability both within and among subpopulations. Thus, higher variance in the reproductive success of clones generates heterozygous excesses within subpopulations and also increases genetic differentiation between them. Migration occurring before and after asexual reproduction has different effects on the patterns of F(IS) and F(ST). When males and females display different degrees of reproductive skew or migration rates, we observe differences in their respective population genetic structure. While results of the model apply to any organism alternating sexual and clonal reproductions (e.g. all parasitic trematodes, many plants, and all aphididae), we finally confront some of these theoretical expectations to empirical data from Schistosoma mansoni infecting Rattus rattus in Guadeloupe.

  20. Life cycle of the multiarmed sea star Coscinasterias acutispina (Stimpson, 1862) in laboratory culture: sexual and asexual reproductive pathways.

    Science.gov (United States)

    Shibata, Daisuke; Hirano, Yoshiaki; Komatsu, Miéko

    2011-05-01

    The multiarmed sea star Coscinasterias acutispina generally has 7-10 arms and 2-5 madreporites. It is known to be able to reproduce by asexual fission, and we have previously observed that this species also has the ability to reproduce sexually; however, there has been no report until now of spawning in this species. We succeeded in establishing a long-term culture of juveniles produced by artificial fertilization. Twelve months after the completion of metamorphosis, three individuals had six arms of the same length and a madreporite. At this time, fission occurred in two of these individuals, while the remaining individual underwent fission four months later. Each sea star divided into two halves, provided with three arms each. Thereafter, four or five new arms and two or four madreporites were formed anew in each of the six daughter sea-stars, so that by 30 days after the first fission the number of arms and madreporites in each was similar to that in adults. A second fission occurred in four of these six individuals, four or five months after the first fission, and in three of them the plane of division was the same as that of the first fission. The original three individuals eventually proliferated to 12 by undergoing fission. All individuals had fully developed gonads by 1-3 months after the second fission. Some of them eventually spawned under laboratory culture, and the resulting larvae metamorphosed into juveniles. Our observations demonstrate that individuals of C. acutispina possess the potential for both sexual and asexual reproduction.

  1. Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays

    Directory of Open Access Journals (Sweden)

    Saleh Dounia

    2012-03-01

    Full Text Available Abstract Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i two strains of opposite mating types including (ii at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs. Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar

  2. Relative importance of various regeneration mechanisms in different restoration stages of Quercus variabilis forest after selective logging

    Directory of Open Access Journals (Sweden)

    Yaoqin Xue

    2014-08-01

    Full Text Available Aim of study: Quercus variabilis (Chinese cork oak reproduces asexually and sexually. This study aimed to determine the status and growth of asexual and sexual recruits of Q. variabilis in different forest recovery stages.Area of study: Three selective logged stands and one unlogged stand in Q. variabilis forest, Shaanxi Province, China.Material and Methods: Origin, number, basal diameter, height and size structure of Q. variabilis shoots (height ≤200 cm were investigated in the plots of 5, 10, and 20-years post-logging stands and unlogged stand. Effects of recovery stage on the density and growth of the three original recruits (stump sprouts, stem base sprouts and true seedlings were analysis by One-way ANOVA.Main results: Sprouts dominated logged stands, whereas true seedlings dominated unlogged stand, stem base sprouts only existed in 20-years post-logging and unlogged stands. Stump sprout density and sprout number per stump both declined with extended post-logging time. True seedlings density increased from 7 to 20 shoots/100 m2 as the postlogging time extended, and peaked in unlogged stand (94 shoots/100 m2. An ongoing size structure was observed in true seedlings in all stands. Stump sprouts were taller and greater than true seedlings.Research highlights: Stump sprouts contributed more to Q. variabilis forest recovery in the early stage after disturbance. The contribution of true seedlings was limited in the same stage, but they were beneficial for population long-term development. Stem base sprouts were most likely to be a survival strategy rather than a reproductive strategy.Key words: asexual reproduction; true seedling; post-logging time; Chinese cork oak.

  3. Artificial blood

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2008-01-01

    Full Text Available Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  4. Artificial blood.

    Science.gov (United States)

    Sarkar, Suman

    2008-07-01

    Artificial blood is a product made to act as a substitute for red blood cells. While true blood serves many different functions, artificial blood is designed for the sole purpose of transporting oxygen and carbon dioxide throughout the body. Depending on the type of artificial blood, it can be produced in different ways using synthetic production, chemical isolation, or recombinant biochemical technology. Development of the first blood substitutes dates back to the early 1600s, and the search for the ideal blood substitute continues. Various manufacturers have products in clinical trials; however, no truly safe and effective artificial blood product is currently marketed. It is anticipated that when an artificial blood product is available, it will have annual sales of over $7.6 billion in the United States alone.

  5. Blood Clots

    Science.gov (United States)

    ... or prevent blood clots from dissolving properly. Risk factors for excessive blood clotting include Certain genetic disorders Atherosclerosis Diabetes Atrial fibrillation Overweight, obesity, and metabolic syndrome Some medicines Smoking deep vein ...

  6. Blood Transfusion

    Science.gov (United States)

    ... to their work or home. The availability of plastic bags that can have one or more satellite bags ... in preparing the donated blood. The use of plastic bags allows the blood center to make a variety ...

  7. Fusion: a tale of recombination in an asexual fungus: The role of nuclear dynamics and hyphal fusion in horizontal chromosome transfer in Fusarium oxysporum

    OpenAIRE

    Shahi, S.

    2016-01-01

    Recent studies have shown that not only meiotic recombination is responsible for the fast evolution of fungal pathogens. In the asexual fungus F. oxysporum (Fo) the "fast" evolving part of the genome is organized into small chromosomes and one such chromosome houses all effector genes and is referred to as the "pathogenicity" chromosome. This pathogenicity chromosome can be horizontally transferred to a non-pathogenic strain, conferring pathogenicity. Here we use Fo as a model organism to add...

  8. The pattern of genetic variability in apomictic clones of Taraxacum officinale indicates the alternation of asexual and sexual histories of apomicts.

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    Luboš Majeský

    Full Text Available Dandelions (genus Taraxacum comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP markers. Our results indicated that significant genetic similarity existed within accessions with low numbers of genotypes. Genotypic variability was high among accessions but low within accessions. Clustering methods discriminated individuals into nine groups corresponding to their phenotypes. Furthermore, two groups of apomictic genotypes were observed, which suggests that they had different asexual histories. A matrix compatibility test suggests that most of the variability within accession groups was mutational in origin. However, the presence of recombination was also detected. The accumulation of mutations in asexual clones leads to the establishment of a network of clone mates. However, this study suggests that the clones primarily originated from the hybridisation between sexual and apomicts.

  9. The pattern of genetic variability in apomictic clones of Taraxacum officinale indicates the alternation of asexual and sexual histories of apomicts.

    Science.gov (United States)

    Majeský, Luboš; Vašut, Radim J; Kitner, Miloslav; Trávníček, Bohumil

    2012-01-01

    Dandelions (genus Taraxacum) comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds) in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe) were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP) markers. Our results indicated that significant genetic similarity existed within accessions with low numbers of genotypes. Genotypic variability was high among accessions but low within accessions. Clustering methods discriminated individuals into nine groups corresponding to their phenotypes. Furthermore, two groups of apomictic genotypes were observed, which suggests that they had different asexual histories. A matrix compatibility test suggests that most of the variability within accession groups was mutational in origin. However, the presence of recombination was also detected. The accumulation of mutations in asexual clones leads to the establishment of a network of clone mates. However, this study suggests that the clones primarily originated from the hybridisation between sexual and apomicts.

  10. Isolation and analysis of differentially expressed genes during asexual sporulation in liquid static culture of Ganoderma lucidum by suppression subtractive hybridization.

    Science.gov (United States)

    Xu, Jun-Wei; Zhao, Wei; Xu, Yi-Ning; Zhong, Jian-Jiang

    2012-04-01

    Ganoderma lucidum differentiates in liquid static culture by forming aerial mycelia and asexual spores, and this differentiation process is accompanied by higher production of anti-tumor compounds ganoderic acids. To gain an insight into the molecular events during asexual sporulation of G. lucidum, comparative transcriptome analysis using suppression subtractive hybridization (SSH) technique was performed to identify preferentially expressed genes in liquid static culture vs. in traditional shaking culture. After macroarray analysis of 1920 cDNAs from SSH library, 147 unigenes which exhibited high expression in static culture were identified. Among these sequences, putative translations of 88 unigenes possessed much similarity to known proteins involved in cell organization, signal transduction, cell metabolism, protein biosynthesis and transcription regulation; 13 had significant similarity to hypothetical proteins; the remaining 46 showed little or no similarity to GenBank sequences. RT-qPCR analysis confirmed increases in transcripts of selected genes under liquid static culture condition. The results of this study present the useful application of EST analysis on G. lucidum and provide preliminary indication of gene expression putatively involved in asexual sporulation process.

  11. Pattern of pre-existing IgG subclass responses to a panel of asexual stage malaria antigens reported during the lengthy dry season in Daraweesh, Sudan

    DEFF Research Database (Denmark)

    Nasr, A; Iriemenam, N C; Troye-Blomberg, M;

    2011-01-01

    The anti-malarial IgG immune response during the lengthy and dry season in areas of low malaria transmission as in Eastern Sudan is largely unknown. In this study, ELISA was used for the measurement of pre-existing total IgG and IgG subclasses to a panel of malaria antigens, MSP2-3D7, MSP2-FC27, ...

  12. Patch stage of mycosis fungoides

    Directory of Open Access Journals (Sweden)

    Mavarkar Laxman

    2001-01-01

    Full Text Available Parapsoriasis is aeon troversial topic. There are many studies regarding the relationship of parapsoriasis to lymphoma but no correlation between histology and clinical appearance. Parapsoriasis satisfies histologic criteria for mycosis fungoides and therefore it should be considered as patch stage of mycosis fungoides. A 30-year-old man presented with scaly skin lesions over the trunk since 4 years. Routine blood and urine investigations were normal. Skin biopsy from the lesion revealed atypical lymphocytes within the epidermis without spongiosis.

  13. Blood Facts and Statistics

    Science.gov (United States)

    ... Facts and Statistics Printable Version Blood Facts and Statistics Facts about blood needs Facts about the blood ... to Top Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells ...

  14. Virulence and Molecular Analyses Support Asexual Reproduction of Puccinia striiformis f. sp. tritici in the U.S. Pacific Northwest.

    Science.gov (United States)

    Cheng, P; Chen, X M

    2014-11-01

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici, occurs every year and causes significant yield losses in the U.S. Pacific Northwest (PNW). A large number of P. striiformis f. tritici races are identified every year and predominant races have changed rapidly. Barberry and mahonia plants, which have been identified under controlled conditions as alternate hosts for the fungus, are found in the region. However, whether sexual reproduction occurs in the P. striiformis f. sp. tritici population under natural conditions is not clear. To determine the reproduction mode of the P. striiformis f. sp. tritici population using virulence and molecular markers, a systematic collection of leaf samples with a single stripe of uredia was made in 26 fields in the PNW in 2010. In total, 270 isolates obtained from the PNW collection, together with 66 isolates from 20 other states collected in the same year, were characterized by virulence tests and simple sequence repeat (SSR) markers. In total, 21 races and 66 multilocus genotypes (MLGs) were detected, of which 15 races and 32 MLGs were found in the PNW. Cluster analysis with the SSR marker data revealed two genetic groups, which were significantly correlated to the two virulence groups. The analyses of genotype/individual ratio, multilocus linkage disequilibrium, and heterozygosity strongly supported asexual reproduction for the pathogen population in the PNW, as well as other regions of the United States.

  15. Homogeneous population of the brown alga Sargassum polycystum in Southeast Asia: possible role of recent expansion and asexual propagation.

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    Sze Wai Chan

    Full Text Available Southeast Asia has been known as one of the biodiversity hotspots in the world. Repeated glacial cycles during Pleistocene were believed to cause isolation of marine taxa in refugia, resulting in diversification among lineages. Recently, ocean current was also found to be another factor affecting gene flow by restricting larval dispersal in animals. Macroalgae are unique in having mode of reproduction that differs from that of animals. Our study on the phylogeographical pattern of the brown macroalga Sargassum polycystum using nuclear Internal Transcribed Spacer 2 (ITS2, plastidal RuBisCO spacer (Rub spacer and mitochondrial cytochrome oxidase subunit-III (Cox3 as molecular markers revealed genetic homogeneity across 27 sites in Southeast Asia and western Pacific, in sharp contrast to that revealed from most animal studies. Our data suggested that S. polycystum persisted in single refugium during Pleistocene in a panmixia pattern. Expansion occurred more recently after the Last Glacial Maximum and recolonization of the newly flooded Sunda Shelf could have involved asexual propagation of the species. High dispersal ability through floating fronds carrying developing germlings may also contribute to the low genetic diversity of the species.

  16. FgFlbD regulates hyphal differentiation required for sexual and asexual reproduction in the ascomycete fungus Fusarium graminearum.

    Science.gov (United States)

    Son, Hokyoung; Kim, Myung-Gu; Chae, Suhn-Kee; Lee, Yin-Won

    2014-11-01

    Fusarium graminearum is a filamentous fungal plant pathogen that infects major cereal crops. The fungus produces both sexual and asexual spores in order to endure unfavorable environmental conditions and increase their numbers and distribution across plants. In a model filamentous fungus, Aspergillus nidulans, early induction of conidiogenesis is orchestrated by the fluffy genes. The objectives of this study were to characterize fluffy gene homologs involved in conidiogenesis and their mechanism of action in F. graminearum. We characterized five fluffy gene homologs in F. graminearum and found that FlbD is the only conserved regulator for conidiogenesis in A. nidulans and F. graminearum. Deletion of fgflbD prevented hyphal differentiation and the formation of perithecia. Successful interspecies complementation using A. nidulans flbD demonstrated that the molecular mechanisms responsible for FlbD functions are conserved in F. graminearum. Moreover, abaA-wetA pathway is positively regulated by FgFlbD during conidiogenesis in F. graminearum. Deleting fgflbD abolished morphological effects of abaA overexpression, which suggests that additional factors for FgFlbD or an AbaA-independent pathway for conidiogenesis are required for F. graminearum conidiation. Importantly, this study led to the construction of a genetic pathway of F. graminearum conidiogenesis and provides new insights into the genetics of conidiogenesis in fungi.

  17. Efficient production of bioactive metabolites from Antrodia camphorata ATCC 200183 by asexual reproduction-based repeated batch fermentation.

    Science.gov (United States)

    Li, Hua-Xiang; Lu, Zhen-Ming; Geng, Yan; Gong, Jin-Song; Zhang, Xiao-Juan; Shi, Jin-Song; Xu, Zheng-Hong; Ma, Yan-He

    2015-10-01

    Large-scale submerged fermentation (SmF) of Antrodia camphorata (A. camphorata) usually encounters challenges including tedious preparation of mycelial inoculum, long fermentation period (10-14 d), and poor repeatability. Here we developed an asexual reproduction-based repeated batch fermentation (RBF) process for bioactive metabolites production by A. camphorata ATCC 200183. Compared with traditional batch fermentation, production time was shortened to 58 d from 80 d (overall time for eight cycles) using the RBF process established in this study, and accordingly, the productivities of bioactive metabolites (including antrodins) were improved by 40-60%. Kinetic parameters (α is 2.1-18.7 times as β) indicated that the cell growth was the major contribution for bioactive metabolites production. The RBF shows excellent batch-repeatability (Pearson correlation coefficient of 0.998±0.001), together with advantages of energy-efficient, low cost, and labor-saving, RBF process can be implemented to SmF by other filamentous fungi.

  18. Regeneration and asexual reproduction share common molecular changes: upregulation of a neural glycoepitope during morphallaxis in Lumbriculus.

    Science.gov (United States)

    Martinez, Veronica G; Menger, Gus J; Zoran, Mark J

    2005-05-01

    Neural morphallaxis is a regenerative process characterized by wide-spread anatomical and physiological changes in an adult nervous system. During segmental regeneration of the annelid worm, Lumbriculus variegatus, neural morphallaxis involved a reorganization of sensory, interneuronal, and motor systems as posterior fragments gained a more anterior body position. A monoclonal antibody, Lan 3-2, which labels a neural glyco-domain in the leech, was reactive in Lumbriculus. In the worm, this antibody labeled neural structures, particularly axonal tracts and giant fiber pathways of the central nervous system. A 60kDa protein, possessing a lumbriculid mannose-rich glycoepitope, was upregulated during neural morphallaxis, peaking in its expression at 3 weeks post-amputation. Peak upregulation of the Lan 3-2 epitope, or the protein possessing it, corresponded to the time of major neurobehavioral plasticity during regeneration. Analyses of asexually reproducing animals also revealed induction of the Lan 3-2 epitope. In this developmental context, Lan 3-2 epitope upregulation was also confined to segments expressing both changes in positional identity and neurobehavioral plasticity, but these molecular and behavioral changes occurred prior to body fragmentation. These results suggest that the lumbriculid Lan 3-2 glycoepitope and proteins that bear them have been co-opted for neural morphallactic programs, induced both in anticipation of reproductive fragmentation and in compensation for injury-induced fragmentation.

  19. Genomic and metabolic characterisation of alkaloid biosynthesis by asexual Epichloë fungal endophytes of tall fescue pasture grasses.

    Science.gov (United States)

    Ekanayake, Piyumi N; Kaur, Jatinder; Tian, Pei; Rochfort, Simone J; Guthridge, Kathryn M; Sawbridge, Timothy I; Spangenberg, German C; Forster, John W

    2017-01-04

    Symbiotic associations between tall fescue grasses and asexual Epichloë fungal endophytes exhibit biosynthesis of alkaloid compounds causing both beneficial and detrimental effects. Candidate novel endophytes with favourable chemotypic profiles have been identified in germplasm collections by screening for genetic diversity, followed by metabolite profile analysis in endogenous genetic backgrounds. A subset of candidates was subjected to genome survey sequencing to detect the presence or absence and structural status of known genes for biosynthesis of the major alkaloid classes. The capacity to produce specific metabolites was directly predictable from metabolic data. In addition, study of duplicated gene structure in heteroploid genomic constitutions provided further evidence for the origin of such endophytes. Selected strains were inoculated into meristem-derived callus cultures from specific tall fescue genotypes to perform isogenic comparisons of alkaloid profile in different host backgrounds, revealing evidence for host-specific quantitative control of metabolite production, consistent with previous studies. Certain strains were capable of both inoculation and formation of longer-term associations with a nonhost species, perennial ryegrass (Lolium perenne L.). Discovery and primary characterisation of novel endophytes by DNA analysis, followed by confirmatory metabolic studies, offers improvements of speed and efficiency and hence accelerated deployment in pasture grass improvement programs.

  20. LAMMER Kinase LkhA plays multiple roles in the vegetative growth and asexual and sexual development of Aspergillus nidulans.

    Directory of Open Access Journals (Sweden)

    Eun-Hye Kang

    Full Text Available LAMMER kinase plays pivotal roles in various physiological processes in eukaryotes; however, its function in filamentous fungi is not known. We performed molecular studies on the function of the Aspergillus nidulans LAMMER kinase, LkhA, and report its involvement in multiple developmental processes. The gene for LkhA was highly expressed during reproductive organ development, such as that of conidiophores and cleistothecia. During vegetative growth, the patterns of germ tube emergence and hyphal polarity were changed and septation was increased by lkhA deletion. Northern analyses showed that lkhA regulated the transcription of brlA, csnD, and ppoA, which supported the detrimental effect of lkhA-deletion on asexual and sexual differentiation. LkhA also affected expression of cyclin-dependent kinase NimX(cdc2, a multiple cell cycle regulator, and StuA, an APSES family of fungal transcription factors that play pivotal roles in multiple differentiation processes. Here, for the first time, we present molecular evidence showing that LAMMER kinase is involved in A. nidulans development by modulating the expression of key regulators of developmental processes.

  1. Cord Blood

    Directory of Open Access Journals (Sweden)

    Saeed Abroun

    2014-05-01

    Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

  2. A single homeobox gene triggers phase transition, embryogenesis and asexual reproduction.

    Science.gov (United States)

    Horst, Nelly A; Katz, Aviva; Pereman, Idan; Decker, Eva L; Ohad, Nir; Reski, Ralf

    2016-01-18

    Plants characteristically alternate between haploid gametophytic and diploid sporophytic stages. Meiosis and fertilization respectively initiate these two different ontogenies(1). Genes triggering ectopic embryo development on vegetative sporophytic tissues are well described(2,3); however, a genetic control of embryo development from gametophytic tissues remains elusive. Here, in the moss Physcomitrella patens we show that ectopic overexpression of the homeobox gene BELL1 induces embryo formation and subsequently reproductive diploid sporophytes from specific gametophytic cells without fertilization. In line with this, BELL1 loss-of-function mutants have a wild-type phenotype, except that their egg cells are bigger and unable to form embryos. Our results identify BELL1 as a master regulator for the gametophyte-to-sporophyte transition in P. patens and provide mechanistic insights into the evolution of embryos that can generate multicellular diploid sporophytes. This developmental innovation facilitated the colonization of land by plants about 500 million years ago(4) and thus shaped our current ecosystems.

  3. 社区早期糖尿病肾病患者强化血糖控制研究*%Study of the intensified blood sugar control for the patients with the diabetic nephropathy in their early stage in the community

    Institute of Scientific and Technical Information of China (English)

    周晓燕; 薛慧娟; 郁静华; 祝捷

    2013-01-01

      目的:探讨强化血糖控制对社区早期糖尿病肾病患者的干预效果。方法:将160例社区早期糖尿病肾病患者随机分为强化组和对照组,强化组糖化血红蛋白控制在≤6.0%,对照组糖化血红蛋白≤7.0%,观察两组患者干预前后空腹血糖、糖化血红蛋白、血脂、血压及尿微量白蛋白/肌酐比值的变化。结果:两组经干预后血脂、血压均有所改善;空腹血糖、糖化血红蛋白、尿微量白蛋白/肌酐比值下降,强化组尿微量白蛋白/肌酐下降较对照组明显(P<0.05)。结论:控制早期糖尿病肾病患者饮食、血糖、血压及血脂水平能够降低尿微量白蛋白/肌酐比值,严格的血糖控制有利于延缓早期糖尿病肾病的发生发展。%Objective:To explore the intervention effect of the intensified blood sugar control of the patients with of diabetic nephropathy in their early stage in the community. Method:One hundred and sixty patients with diabetic nephropathy were randomly divided into the intensified group and control group. The glycosylated hemoglobin was controlled ≤ 6.0%in the intensified group, and≤7.0%in the control group. The changes of fasting blood glucose, glycosylated hemoglobin, blood fat, blood pressure, urine microalbumin/creatinine were compared in the patients in the two groups before and after intervention. Result:Both blood fat and blood pressures were improved in the two groups after intervention. Fasting blood glucose, glycosylated hemoglobin, the rate of urine microalbumin/creatinine decreased. Urine microalbumin/creatinine decreased more obviously in the intensified group (P<0.05). Conclusion:Control of diet, blood sugar, blood pressure and blood fat of the nephropathy patients in their early stage is capable of decreasing the rate of urine microalbumin/creatinine. Strictly controlling the glycosylated hemoglobin is of benefit to prolonging the early occurrence and development of

  4. Asexual populations of the human malaria parasite, Plasmodium falciparum, use a two-step genomic strategy to acquire accurate, beneficial DNA amplifications.

    Directory of Open Access Journals (Sweden)

    Jennifer L Guler

    Full Text Available Malaria drug resistance contributes to up to a million annual deaths. Judicious deployment of new antimalarials and vaccines could benefit from an understanding of early molecular events that promote the evolution of parasites. Continuous in vitro challenge of Plasmodium falciparum parasites with a novel dihydroorotate dehydrogenase (DHODH inhibitor reproducibly selected for resistant parasites. Genome-wide analysis of independently-derived resistant clones revealed a two-step strategy to evolutionary success. Some haploid blood-stage parasites first survive antimalarial pressure through fortuitous DNA duplications that always included the DHODH gene. Independently-selected parasites had different sized amplification units but they were always flanked by distant A/T tracks. Higher level amplification and resistance was attained using a second, more efficient and more accurate, mechanism for head-to-tail expansion of the founder unit. This second homology-based process could faithfully tune DNA copy numbers in either direction, always retaining the unique DNA amplification sequence from the original A/T-mediated duplication for that parasite line. Pseudo-polyploidy at relevant genomic loci sets the stage for gaining additional mutations at the locus of interest. Overall, we reveal a population-based genomic strategy for mutagenesis that operates in human stages of P. falciparum to efficiently yield resistance-causing genetic changes at the correct locus in a successful parasite. Importantly, these founding events arise with precision; no other new amplifications are seen in the resistant haploid blood stage parasite. This minimizes the need for meiotic genetic cleansing that can only occur in sexual stage development of the parasite in mosquitoes.

  5. Comparative anatomy and histology of developmental and parasitic stages in the life cycle of the lined sea anemone Edwardsiella lineata.

    Science.gov (United States)

    Reitzel, Adam M; Daly, Marymegan; Sullivan, James C; Finnerty, John R

    2009-02-01

    The evolution of parasitism is often accompanied by profound changes to the developmental program. However, relatively few studies have directly examined the developmental evolution of parasitic species from free-living ancestors. The lined sea anemone Edwardsiella lineata is a relatively recently evolved parasite for which closely related free-living outgroups are known, including the starlet sea anemone Nematostella vectensis. The larva of E. lineata parasitizes the ctenophore Mnemiopsis leidyi, and, once embedded in its host, the anemone assumes a novel vermiform body plan. That we might begin to understand how the developmental program of this species has been transformed during the evolution of parasitism, we characterized the gross anatomy, histology, and cnidom of the parasitic stage, post-parasitic larval stage, and adult stage of the E. lineata life cycle. The distinct parasitic stage of the life cycle differs from the post-parasitic larva with respect to overall shape, external ciliation, cnida frequency, and tissue architecture. The parasitic stage and planula both contain holotrichs, a type of cnida not previously reported in Edwardsiidae. The internal morphology of the post-parasitic planula is extremely similar to the adult morphology, with a complete set of mesenterial tissue and musculature despite this stage having little external differentiation. Finally, we observed 2 previously undocumented aspects of asexual reproduction in E. lineata: (1) the parasitic stage undergoes transverse fission via physal pinching, the first report of asexual reproduction in a pre-adult stage in the Edwardsiidae; and (2) the juvenile polyp undergoes transverse fission via polarity reversal, the first time this form of fission has been reported in E. lineata.

  6. Immunoelectrophoresis - blood

    Science.gov (United States)

    IEP - serum; Immunoglobulin electrophoresis - blood; Gamma globulin electrophoresis; Serum immunoglobulin electrophoresis; Amyloidosis - electrophoresis serum; Multiple myeloma - serum electrophoresis; Waldenström - serum electrophoresis

  7. Understanding Blood Counts

    Science.gov (United States)

    ... Lab and Imaging Tests Understanding Blood Counts Understanding Blood Counts Understanding Blood Counts SHARE: Print Glossary Blood cell counts give ... your blood that's occupied by red cells. Normal Blood Counts Normal blood counts fall within a range ...

  8. Cervical Cancer Stage IVA

    Science.gov (United States)

    ... historical Searches are case-insensitive Cervical Cancer Stage IVA Add to My Pictures View /Download : Small: 756x576 ... Large: 3150x2400 View Download Title: Cervical Cancer Stage IVA Description: Stage IVA cervical cancer; drawing and inset ...

  9. BLOOD DONATION

    CERN Multimedia

    SC Unit

    2008-01-01

    A blood donation, organized by EFS (Etablissement Français du Sang) of Annemasse will take place On Wednesday 12 November 2008, from 8:30 to 16:00, at CERN Restaurant 2 If possible, please, bring your blood group Card.

  10. Blood donation

    CERN Multimedia

    GS Department

    2009-01-01

    A blood donation is organised by the Cantonal Hospital of Geneva On Thursday 19 March 2009 from 9 a.m. to 5 p.m. CERN RESTAURANT 2 Number of donations during the last blood donations :135 donors in July 2008 122 donors in November 2008 Let’s do better in 2009 !!! Give 30 minutes of your time to save lives...

  11. Influences of Different Habitats on Asexual Propagation of Wild Gastrodia elata f. glauca being Domesticated in Ganzi

    Institute of Scientific and Technical Information of China (English)

    Xueqiang XIE

    2015-01-01

    Objective] The influences of different habitats on asexual propagation of wild Geg (abbreviation for Gastrodia elata Bl. f. glauca S. Chow) being domesticat-ed in Ganzi prefecture was studied. [Method] The research trial was carried out in the fol owing three kinds of habitats at the same time: the plastic greenhouses, the birch forest of shady slope and the shrubbery of sunny slope, and the results were analyzed with group data average hypothesis test method. [Result] The overal tuber (the juvenile tuber, the immature tuber and the mature tuber) yield and the mature tuber yield were both very significantly higher in the plastic greenhouses than in the other two types of habitats, and respectively reached 9.52 and 6.70 kg/m2; the ma-ture tuber drying rate was dramatical y or very dramatical y lower in the plastic greenhouses than in the other two types of habitats, and was 23.84%; the stabilities of the overal tuber yield, the mature tuber yield and the drying rate were al re-duced in the order of greenhouses, birch forest and shrubbery; and the dry mature tuber yield of the plastic greenhouses was the highest in the three kinds of habi-tats, and was 1.60 kg/m2. [Conclusion] A good habitat had to be created or chosen in the domesticating cultivation of the wild Geg in Ganzi prefecture. The preferred choice was the plastic greenhouse, the alternative one was the deciduous broad-leaved forest of shady slope. The imitating wild planting of the wild Geg should be done in the warm moist deciduous broad-leaved forest of shady slope.

  12. Marginal coral populations: the densest known aggregation of Pocillopora in the Galápagos Archipelago is of asexual origin

    Directory of Open Access Journals (Sweden)

    Iliana B Baums

    2014-11-01

    Full Text Available Coral populations at distributional margins frequently experience suboptimal and variable conditions. Recurrent El Niño-Southern Oscillation (ENSO warming events have caused extensive mortality of reef-building corals in the Eastern Pacific, and particularly impacted branching pocilloporid corals in the Galápagos Islands. Pocillopora spp. were previously more common and formed incipient reefs at several locations in the Archipelago but now occur as scattered colonies. Here, we report an unusually concentrated aggregation of colonies and evaluate their current genetic diversity. In particular we focus on a large population of 1614 live Pocillopora colonies found in a volcanic lagoon along the southern shore of Isabela Island. Forty seven colonies were sampled, primarily using a spatially explicit sampling design, and all colonies belonged to Pocillopora mitochondrial open reading frame lineage type 3a. Typing of additional Pocillopora samples (n = 40 from three other islands indicated that this stand is the only known representative of type 3a in the Galápagos Islands. The Isabela Pocillopora type 3a colonies harbored Symbiodinium ITS-2 clade C1d. Multilocus genotyping (n = 6 microsatellites capable of resolving individual clones indicated that this stand is monogenotypic and thus the high density of colonies is a result of asexual reproduction, likely via fragmentation. Colony size distribution, while imperfect, suggested the stand regrew from remnant colonies that survived the 1997/98 ENSO event but may postdate the 1982/83 ENSO. The community of Pocillopora colonies at Isabela is of particular ecological value due to its high density and support of associated organisms such as fish and benthic invertebrates. The Galapagos Pocillopora corals will continue to provide insights into the genetic structure and population dynamics of marginal coral populations.

  13. Aspergillus asexual reproduction and sexual reproduction are differentially affected by transcriptional and translational mechanisms regulating stunted gene expression.

    Science.gov (United States)

    Wu, J; Miller, B L

    1997-10-01

    The Stunted protein (StuAp) is a member of a family of transcription factors that regulate fungal development and cell cycle progression. Regulated stuA gene expression is required for correct cell pattern formation during asexual reproduction (conidiation) and for initiation of the sexual reproductive cycle in Aspergillus nidulans. Transcriptional initiation from two different promoters yields overlapping mRNAs (stuA alpha and stuAbeta) that upon translation yield the same protein. Here we show that multiple regulatory mechanisms interact to control (i) developmental competence-dependent expression of both transcripts and (ii) induction-dependent expression of stuA alpha, but not stuAbeta, by the conidiation-specific Bristle (BrlAp) transcriptional activator. Quantitative levels of both mRNAs are further modulated by (i) an activator(s) located at a far-upstream upstream activation sequence, (ii) feedback regulation by StuAp, and (iii) positive translational regulation that requires the peptide product of a micro-open reading frame unique to the stuA alpha mRNA 5' untranslated region. Gradients in stuA alpha expression were most important for correct cell and tissue type development. Threshold requirements were as follows: metula-phialide differentiation < ascosporogenesis < cleistothecial shell-Hülle cell differentiation. Altered stuA expression affected conidiophore morphology and conidial yields quantitatively but did not alter the temporal development of cell types or conidiophore density. By contrast, the sexual cycle showed both temporal delay and quantitative reduction in the number of cleistothecial initials but normal morphogenesis of tissue types.

  14. The 'mother of thousands' (Kalanchoë daigremontiana): a plant model for asexual reproduction and CAM studies.

    Science.gov (United States)

    Garcês, Helena; Sinha, Neelima

    2009-10-01

    The genus Kalanchoë plays an important role in the investigation of biochemical, physiological and phylogenetic aspects of Crassulacean acid metabolism (CAM) in plants, which is an important evolutionary adaptation of the photosynthetic carbon assimilation pathway to arid environments. In addition, natural compounds extracted from tissues of Kalanchoë have potential applicability in treating tumors and inflammatory and allergic diseases, and have been shown to have insecticidal properties. Kalanchoë daigremontiana (Hamet & Perrier) originated in Madagascar and reproduces asexually by spontaneously forming whole plantlets on leaves. Plantlets develop symmetrically along the leaf margins on leaf notches, closely resembling zygotic embryos in development, and once the root system is formed, they detach from the mother-leaf, fall to the ground, and grow into new plants. This phenomenon is also found in other species from this same genus; however, the formation of leaf-plantlets is variable among species. Nevertheless, all species illustrate the remarkable ability of plant somatic cells to regenerate an entire organism, which has fascinated the scientific community for many years. It was only recently that the morphogenic process involved in the origin of K. daigremontiana plantlets was determined using molecular and genetic tools: K. daigremontiana forms plantlets by co-opting both organogenesis and embryogenesis programs into leaves. The ability of K. daigremontiana species to form somatic embryos outside of a seed environment provides an attractive model system to study somatic embryogenesis in nature, particularly the molecular mechanism involved in the acquisition of competence by vegetative cells to make embryos without fertilization.

  15. Colonization history and clonal richness of asexual Daphnia in periglacial habitats of contrasting age in West Greenland.

    Science.gov (United States)

    Haileselasie, Tsegazeabe H; Mergeay, Joachim; Weider, Lawrence J; Jeppesen, Erik; De Meester, Luc

    2016-07-01

    Due to climate change, Arctic ice sheets are retreating. This leads to the formation of numerous new periglacial ponds and lakes, which are being colonized by planktonic organisms such as the water flea Daphnia. This system provides unique opportunities to test genotype colonization dynamics and the genetic assemblage of populations. Here, we studied clonal richness of the Daphnia pulex species complex in novel periglacial habitats created by glacial retreat in the Jakobshavn Isbrae area of western Greenland. Along a 10 km transect, we surveyed 73 periglacial habitats out of which 61 were colonized by Daphnia pulex. Hence, for our analysis, we used 21 ponds and 40 lakes in two clusters of habitats differing in age (estimated 150 years). We tested the expectation that genetic diversity would be low in recently formed (i.e. young), small habitats, but would increase with increasing age and size. We identified a total of 42 genetically distinct clones belonging to two obligately asexual species of the D. pulex species complex: D. middendorffiana and the much more abundant D. pulicaria. While regional clonal richness was high, most clones were rare: 16 clones were restricted to a single habitat and the five most widespread clones accounted for 68% of all individuals sampled. On average, 3·2 clones (range: 1-12) coexisted in a given pond or lake. There was no relationship between clonal richness and habitat size when we controlled for habitat age. Whereas clonal richness was statistically higher in the cluster of older habitats when compared with the cluster of younger ponds and lakes, most young habitats were colonized by multiple genotypes. Our data suggest that newly formed (periglacial) ponds and lakes are colonized within decades by multiple genotypes via multiple colonization events, even in the smallest of our study systems (4 m(2) ).

  16. Tainted blood

    DEFF Research Database (Denmark)

    Deleuran, Ida; Sheikh, Zainab Afshan; Hoeyer, Klaus

    2015-01-01

    study of the historical rise and current workings of safety practices in the Danish blood system. Here, we identify a strong focus on contamination in order to avoid 'tainted blood', at the expense of working with risks that could be avoided through enhanced blood monitoring practices. Of further...... significance to this focus are the social dynamics found at the heart of safety practices aimed at avoiding contamination. We argue that such dynamics need more attention, in order to achieve good health outcomes in transfusion medicine. Thus, we conclude that, to ensure continuously safe blood systems, we...... need to move beyond the bifurcation of the social and medical aspects of blood supply as two separate issues and approach social dynamics as key medical safety questions....

  17. What Happens to Donated Blood?

    Science.gov (United States)

    ... week. Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells Platelets Plasma ... About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity ...

  18. Identification and Localization of Minimal MHC-restricted CD8+ T Cell Epitopes within the Plasmodium falciparum AMA1 Protein

    Science.gov (United States)

    2010-08-24

    Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the...A, Muratova O, Awkal M, et al: Phase 1 clinical trial of apical membrane antigen 1: an asexual blood-stage vaccine for Plasmodium falciparum malaria...PfCP-2.9, an asexual blood-stage vaccine candidate of Plasmodium falciparum. Malar J 2010, 9(1):94. 40. Senger T, Becker MR, Schadlich L, Waterboer T

  19. Stage-specific activity of potential antimalarial compounds measured in vitro by flow cytometry in comparison to optical microscopy and hypoxanthine uptake

    Directory of Open Access Journals (Sweden)

    Carmen E Contreras

    2004-03-01

    Full Text Available The evaluation of new antimalarial agents using older methods of monitoring sensitivity to antimalarial drugs are laborious and poorly suited to discriminate stage-specific activity. We used flow cytometry to study the effect of established antimalarial compounds, cysteine protease inhibitors, and a quinolone against asexual stages of Plasmodium falciparum. Cultured P. falciparum parasites were treated for 48 h with different drug concentrations and the parasitemia was determined by flow cytometry methods after DNA staining with propidium iodide. P. falciparum erythrocytic life cycle stages were readily distinguished by flow cytometry. Activities of established and new antimalarial compounds measured by flow cytometry were equivalent to results obtained with microscopy and metabolite uptake assays. The antimalarial activity of all compounds was higher against P. falciparum trophozoite stages. Advantages of flow cytometry analysis over traditional assays included higher throughput for data collection, insight into the stage-specificity of antimalarial activity avoiding use of radioactive isotopes.

  20. How much blood is needed?

    Science.gov (United States)

    Seifried, E; Klueter, H; Weidmann, C; Staudenmaier, T; Schrezenmeier, H; Henschler, R; Greinacher, A; Mueller, M M

    2011-01-01

    Demographic changes in developed countries as their populations age lead to a steady increase in the consumption of standard blood components. Complex therapeutic procedures like haematopoietic stem cell transplantation, cardiovascular surgery and solid organ transplantation are options for an increasing proportion of older patients nowadays. This trend is likely to continue in coming years. On the other hand, novel aspects in transplant regimens, therapies for malignant diseases, surgical procedures and perioperative patient management have led to a moderate decrease in blood product consumption per individual procedure. The ageing of populations in developed countries, intra-society changes in the attitude towards blood donation as an important altruistic behaviour and the overall alterations in our societies will lead to a decline in regular blood donations over the next decades in many developed countries. Artificial blood substitutes or in vitro stem cell-derived blood components might also become alternatives in the future. However, such substitutes are still in early stages of development and will therefore probably not alleviate this problem within the next few years. Taken together, a declining donation rate and an increase in the consumption of blood components require novel approaches on both sides of the blood supply chain. Different blood donor groups require specific approaches and, for example, inactive or deferred donors must be re-activated. Optimal use of blood components requires even more attention.

  1. 不同程度慢性乙型肝炎血脂与HBV DNA关系研究%Relationship between blood lipid levels and HBV-DNA in patients with different stages of chronic hepatitis B

    Institute of Scientific and Technical Information of China (English)

    颜华东; 高国生; 祝成亮; 盛吉芳

    2013-01-01

    目的 探讨慢性乙型肝炎患者不同血脂指标的表达水平及其与病情轻重和HBV DNA的关系.方法 收集2011年1月至2012年10月宁波市第二医院142例慢性乙型病毒性肝炎患者以及44名健康献血员血清,检测总胆固醇(TCHO)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白A1(ApoAl)、载脂蛋白B(ApoB)、载脂蛋白E(ApoE)、脂蛋白a及HBV DNA,对检测结果进行统计学分析.结果 不同病情及不同HBVDNA栽量慢性乙型肝炎患者ApoE水平均显著高于正常对照组(P均<0.05);而其他各血脂指标均低于正常对照组(P均<0.05).ApoE含量与病情轻重呈正相关,而T-CHO、HDL-C、ApoA1则呈负相关.HDL-C、ApoA1含量与HBV DNA载量呈正相关,而T-CHO、LDL-C、ApoB、ApoE则呈负相关.结论 慢性乙型肝炎患者血脂水平受肝脏合成功能以及HBV本身等多种因素的影响.%Objective To investigate the correlations of dislipidemia with disease stages and HBV-DNA in patients with chronic hepatitis B (CHB). Methods Serum samples were collected from 142 CHB patients and 44 healthy controls at Ningbo Second Hospital from January 2011 to October 2012, and the levels of TCHO, HDL-C, LDL-C, ApoAl, ApoB, ApoE, lipo and HBV-DNA were detected. The detected data were statistically analyzed. Results Regardless of disease stages and viral loads, the serum ApoE level was higher in CHB patients than that in the healthy controls ( P < 0. 05 ) , while the levels of other indicators were lower (P < 0. 05 ). The serum ApoE concentration was correlated positively with disease progression, but the levels of T-CHO, HDL-C, and ApoAl were correlated negatively with disease stages. The serum ApoAl concentration was correlated positively with HBV-DNA,but the levels of T-CHO,LDL-C, ApoB and ApoE were correlated negatively with the viral loads. Conclusion Dislipidemia is affected multiple factors such as liver synthesis function and HBV-DNA in CHB

  2. 利用彩色多普勒超声对终末期肾病患者人工动静脉内瘘血管的监测%Using Color Doppler sonography in end-stage renal disease surveillance of artificial blood vessel arteriovenous internal fistula

    Institute of Scientific and Technical Information of China (English)

    顾星; 茅红卫; 季平; 张新源

    2013-01-01

    Objective: The use of Color Doppler sonography monitoring end-stage renal disease artificial vascular arteriove-nous fistula. Methods: 34 cases of Color Doppler sonography in patients with end-stage renal disease artificial arteriovenous fistula vessel diameter, flow velocity, resistance index(RI), blood flow. Results:34 cases of patients with end-stage renal dis-ease in 25 cases of fistula patency good, there are different situations complications in nine cases. Conclusion: Color Doppler sonography in end-stage renal disease artificial arteriovenous fistula of the indicators play an important role in monitoring , artificial arteriovenous fistula inside diameter 3-7 mm, flow rate at 350-800 mL/min can meet the normal amount of hemodialysis.%目的:利用彩色多普勒超声监测终末期肾病患者人工动静脉内瘘的血管。方法:应用彩色多普勒超声测定34例终末期肾病患者人工动静脉内瘘血管内径、血流速度、阻力指数(resistent index,RI)、血流量。结果:34例终末期肾病患者中25例内瘘通畅良好,9例出现不同情况的并发症。结论:彩色多普勒超声在终末期肾病患者人工动静脉内瘘的各项指标监测中起重要作用,人工动静脉内瘘口内径在3~7 mm,血流量在350~800 mL/min时,可满足正常血透量。

  3. Sexual and asexual reproduction in Didemnum rodriguesi (Ascidiacea, Didemnidae Reprodução sexuada e assexuada em Didemnum rodriguesi (Ascidiacea, Didemnidae

    Directory of Open Access Journals (Sweden)

    Nicole F. Ritzmann

    2009-03-01

    Full Text Available Sexual and asexual reproduction and associated population dynamics were investigated in the colonial ascidian Didemnum rodriguesi Rocha & Monniot, 1993 (Didemnidae in southern Brazil. Investment in sexual (production of new individuals and asexual (colony growth reproduction was compared between seasons. Permanently marked quadrats were repeatedly photographed to measure changes in colonies. Eggs and larvae were counted monthly in collected colonies. This species alternates seasonally between sexual (summer and asexual (winter reproduction. In summer, colonies were smaller, brooded eggs and larvae and recruitment rates were greater, while in winter, colony size was larger and eggs and larvae were absent. There is a relationship between fecundity and colony area. Fragmentation and fusion of colonies were similar in summer and winter, as well as mortality. In conclusion, D. rodriguesi has a lifecycle usual for high latitude ascidians with a limited time length for sexual reproduction and alternate investment in sexual and asexual reproduction along the year.Reprodução sexuada e assexuada, mortalidade e a dinâmica de fusões e fissões de colônias de Didemnum rodriguesi Rocha & Monniot, 1993 foram investigados e comparados no sul do Brasil, no inverno e verão. Tais eventos foram analisados por fotografias de áreas permanentemente demarcadas e coletas mensais de colônias. Os resultados indicam que esta espécie alterna sazonalmente a reprodução sexuada (verão e assexuada (inverno. Durante o verão as colônias são mais abundantes e menores, com ovos e larvas incubados e taxas de recrutamento maiores. No inverno há um menor número de colônias, porém de maior tamanho e inférteis. Existe uma relação entre fecundidade e tamanho da colônia. Não foram encontradas diferenças estatísticas no número de eventos de fragmentação e fusão entre o verão e inverno, bem como para mortalidade. Conclui-se que esta espécie tem um ciclo de

  4. Morfología vegetativa y reproducción asexual de Draparnaldia mutabilis (Chaetophoraceae, Chlorophyta), primer registro fundamentado para Argentina

    OpenAIRE

    Karina M. Michetti; Leonardi, Patricia I.; Eduardo J. Cáceres

    2007-01-01

    Draparnaldia mutabilis posee un talo compuesto por un sistema rizoidal postrado reducido y un sistema erguido que muestra una marcada diferenciación entre filamentos axiales y laterales, estos últimos agrupados en fascículos densos, altamente ramificados. La reproducción asexual ocurre por medio de zoósporas que poseen un patrón de germinación erguido. El registro de esta especie constituye la primera cita cierta para la República Argentina. Se presenta además, una clave con las e...

  5. Between Stage and Screen

    NARCIS (Netherlands)

    Tornqvist, Egil

    1996-01-01

    Ingmar Bergman is worldwide known as a film and stage director. Yet no-one has attempted to compare his stage and screen activities. In Between stage and screen Egil Tornqvist examines formal and thematical correspondences and differences between a number of Bergman's stage, screen, and radio produc

  6. Aurelia aurita-Cnidarian with a prominent medusiod stage.

    Science.gov (United States)

    Matveev, Ivan V; Adonin, Leonid S; Shaposhnikova, Tatiana G; Podgornaya, Olga I

    2012-01-15

    Aurelia aurita has a complex life cycle that consists of several stages including alternating generations of medusa and polyps, huge sexual, and tiny asexual stages. Cnidarian is thought to possess two tissue layers: endoderm (gastroderm) and ectoderm, which are separated by mesoglea in medusa. The determination of the composition of the A. aurita jellyfish mesoglea was performed. New protein "mesoglein" was determined as one of the main components of mesoglea. Mesoglein is synthesized by mesogleal cells (Mc), which are populated A. aurita mesoglea as a high molecular mass precursor. Mc are involved in the formation of noncollagenous "elastic" fibers. Deduced amino acid sequence of mesoglein contains Zona Pellucida (ZP) domain and Delta/Serrate/Lag-2 domain. According to reverse transcription PCR, mesoglein is expressed in the mature medusa exclusively in the Mc. The sperm binding to the ZP is particularly important for successful fertilization. Antibodies against mesoglein stain the plate in the place of contact of germinal epithelium and oocyte. The structure found was named the "contact plate." The contact plate could be the precursor of the ZP. All our data suggest that Mc and, probably, the whole mesoglea originate from the epidermis (ectoderm). Computer search for mesoglein relatives reveals Nematostella and Trichoplax proteins as predicted ORFs, indicating that ZP proteins are quite ancient purchase in the evolution.

  7. Blood Typing

    Science.gov (United States)

    ... if you need repeated transfusions, as sickle cell anemia and thalassemia patients do. If blood transfusions are not closely ... the News Article Index About This Site Send Us Your Comments For ...

  8. Blood Disorders

    Science.gov (United States)

    ... people with blood disorders. Magnitude of the Problem Complications from deep vein thrombosis (DVT) kill more people each year than breast cancer, motor vehicle accidents, and HIV combined. Sickle cell trait ...

  9. What's Blood?

    Science.gov (United States)

    ... Rh" because scientists found it while studying Rhesus monkeys. If your blood is positive, you have this ... doctor. © 1995- The Nemours Foundation. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, ...

  10. Artificial blood.

    OpenAIRE

    1983-01-01

    #Blood substitutes have been developed for almost a century. The various type of artificial blood was continuously available on the market. The theme of this report is to identify the best substitute in emergency situation for some patients and science students. The definition of best is given; thus, as the vital part of the report, the comparison between them is described and discussed. Modified hemoglobin, bovine-based hemoglobin and PFCs are three basic types. In terms of the perfor...

  11. Fixed-Dose Artesunate–Amodiaquine Combination vs Chloroquine for Treatment of Uncomplicated Blood Stage P. vivax Infection in the Brazilian Amazon: An Open-Label Randomized, Controlled Trial

    Science.gov (United States)

    Alencar, Aline C.; Melo, Gisely C.; Magalhaes, Belisa L.; Machado, Kim; Alencar Filho, Aristóteles C.; Kuehn, Andrea; Marques, Marly M.; Manso, Monica Costa; Felger, Ingrid; Vieira, José L. F.; Lameyre, Valerie; Daniel-Ribeiro, Claudio T.; Lacerda, Marcus V. G.

    2017-01-01

    Background. Despite increasing evidence of the development of Plasmodium vivax chloroquine (CQ) resistance, there have been no trials comparing its efficacy with that of artemisinin-based combination therapies (ACTs) in Latin America. Methods. This randomized controlled trial compared the antischizontocidal efficacy and safety of a 3-day supervised treatment of the fixed-dose combination artesunate-amodiaquine Winthrop® (ASAQ) versus CQ for treatment of uncomplicated P. vivax infection in Manaus, Brazil. Patients were followed for 42 days. Primary endpoints were adequate clinical and parasitological responses (ACPR) rates at day 28. Genotype-adjustment was performed. Results. From 2012 to 2013, 380 patients were enrolled. In the per-protocol (PP) analysis, adjusted-ACPR was achieved in 100% (165/165) and 93.6% (161/172) of patients in the ASAQ and CQ arm (difference 6.4%, 95% CI 2.7%; 10.1%) at day 28 and in 97.4% (151/155) and 77.7% (129/166), respectively (difference 19.7%, 95% CI 12.9%; 26.5%), at day 42. Apart from ITT D28 assessment, superiority of ASAQ on ACPR was demonstrated. ASAQ presented faster clearance of parasitaemia and fever. Based on CQ blood level measurements, CQ resistance prevalence was estimated at 11.5% (95% CI: 7.5-17.3) up to day 42. At least one emergent adverse event (AE) was recorded for 79/190 (41x6%) in the ASAQ group and for 85/190 (44x7%) in the CQ group. Both treatments had similar safety profiles. Conclusions. ASAQ exhibited high efficacy against CQ resistant P. vivax and is an adequate alternative in the study area. Studies with an efficacious comparator, longer follow-up and genotype-adjustment can improve CQR characterization. Clinical Trials Registration. NCT01378286. PMID:27988484

  12. Comparative study on the blood biochemical indices of primiparous and multiparous dairy cows in perinatal stage%一胎奶牛与经产奶牛围产期血液生化指标对比研究

    Institute of Scientific and Technical Information of China (English)

    于洪江; 沈泰钰; 高三思; 黄宝银; 董志昊; 刘润琪; 何平; 李蕊蕊; 杨威

    2016-01-01

    The purpose of this study was to reflect the regular pattern of changes and differences in the blood biochemical indices between primiparous dairy cows and multiparous dairy cows.Five primiparous and five multiparous healthy dairy cows with similar body condition,year and parity were selected.Blood samples were collected from the vena caudalis mediana using sodium heparin before feeding and milking in the morning at day 7,4,1 d prenatal and day 0,1,3,5,7,9,11,14,17,20 d postpartum,and detecting the glucose (GLU),calcium (Ca),phosphorus (P) and magnesium (Mg),β-hydroxybutyrate (BHBA),free fatty acid (NEFA),total protein (TP),albumin (ALB),globulin (GLO),triglyceride (TG) in the blood.The results showed that there are significant differences in the concentration of GLU between both dairy cows at day 7,4 prenatal (P<0.01) and at 0,3,5,7,9,11,14,17,20 d postpartum(P<0.05).The GLU content reached a peak at the parturition.The concentration of Ca in the primiparous dairy cows is significantly higher than the multiparous dairy cows at day 0,1 postpartum (P<0.01),and significantly increased at day 4,1 prenatal (P<0.05),reaching the lowest at day 0.There are significantly difference in the phosphorus content between both at 0 d (P<0.01),phosphorus content in primiparous was higher than multiparous.The concentration of Mg in the primiparous was significantly higher than multiparous at day 1 postpartum (P<0.05).There is no significant difference in the concentrations of BHBA、NEFA、TG、TP、ALB、GLO between both (P> 0.05),and the concentrations of BHBA,NEFA,TP,ALB,GLO in multiparous dairy cows were slightly higher than primiparous.The results indicate that the Ca,P,Mg and energy metabolism of primiparous dairy cows are better than those of multiparous dairy cows,and there is a higher risk of the nutritional and metabolic diseases after parturition of multiparous dairy cows.%本试验旨在通过对围产期一胎奶牛与经产奶牛血液进行生化指

  13. Blood Transfusion and Donation

    Science.gov (United States)

    ... receiving the blood transfusion. To keep blood safe, blood banks carefully screen donated blood. The risk of catching ... one or more times before the surgery. A blood bank will store your blood for your use. NIH: ...

  14. Blood (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Blood KidsHealth > For Parents > Blood A A A What's ... about the mysterious, life-sustaining fluid called blood. Blood Basics Two types of blood vessels carry blood ...

  15. Catecholamine blood test

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    Norepinephrine -- blood; Epinephrine -- blood; Adrenalin -- blood; Dopamine -- blood ... A blood sample is needed. ... the test. This is especially true if both blood and urine catecholamines are to be measured. You ...

  16. Biology of Blood

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    ... here for the Professional Version Home Blood Disorders Biology of Blood Overview of Blood Resources In This ... Version. DOCTORS: Click here for the Professional Version Biology of Blood Overview of Blood Components of Blood ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  18. Staging Primary CNS Lymphoma

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    ... chromosomes . Other tests, such as fluorescence in situ hybridization (FISH), may also be done to look for ... for, diagnose, and monitor many different conditions. Blood chemistry studies : A procedure in which a blood sample ...

  19. Stages of Wilms Tumor

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    ... abdomen. Blood in the urine. High blood pressure (headache, feeling very tired, chest pain, or trouble seeing ... Cancer Late Effects of Treatment for Childhood Cancer Adolescents and Young Adults with Cancer Children with Cancer: ...

  20. Managing your blood sugar

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    Hyperglycemia - control; Hypoglycemia - control; Diabetes - blood sugar control; Blood glucose - managing ... Know how to: Recognize and treat low blood sugar (hypoglycemia) Recognize and treat high blood sugar (hyperglycemia) ...

  1. Clinical Observation on the Effect of Kidney and Blood Detoxification in Treatment of Patients with Gout at the Remission Stage%滋肾补血解毒合剂对缓解期痛风患者治疗的临床观察

    Institute of Scientific and Technical Information of China (English)

    王艳

    2009-01-01

    Objective To observe the Clinical effect of kidney and blood detoxification in treatment of patients with gout at the remission stage. Methods 51 cases of patients with gout at remission were randomly divided into two groups, with treatment group 26 cases using blood detoxifieation nourishing the kid-hey treatment, 25 cases of the control group under the condition of oral probenecid, benzbromarone and sodium bicarbonate treatment, to compare the clinical in-dicators, efficacy and safety of the two groups after treatment. Results The total effective rate was 92.3% in the treatment group, while the total effective rate was 80.0% in the control group. There was no significant difference between the total effective rates (P >0.05); there was no significant difference in comparison of serum uric acid before and after treatment between the two groups(P >0.05); but there was more significant difference in comparison of serum uric acid before and after treatment in each group(P 0.05.两组治疗前后血尿酸组间比较无显著差异,P>0.05;两组治疗前后血尿酸组内比较有极显著差异,P<0.01.结论 滋肾补血解毒合剂治疗缓解期痛风的疗效可靠,且无不良反应.

  2. Effects of Cd, Co, Cu, Ni and Zn on asexual reproduction and early development of the tropical sea anemone Aiptasia pulchella.

    Science.gov (United States)

    Howe, Pelli L; Reichelt-Brushett, Amanda J; Clark, Malcolm W

    2014-11-01

    Currently few studies present sub-lethal toxicity data for tropical marine species, and there are no routine toxicity tests using marine cnidarians. The symbiotic sea anemone Aiptasia pulchella has been identified as a useful species for ecotoxicological risk assessment, and would provide a tropical marine cnidarian representative. Chronic sub-lethal toxicity tests assessing the effects of 28-day trace metal exposure on asexual reproduction in A. pulchella were investigated, and concentration-dependant reductions in the number of offspring that were produced were evident for all metal exposures. Metal concentration estimates causing 50% reductions in the numbers of asexually-reproduced juveniles after 28-day exposures (28-day effect concentrations 50%: EC50s) were 14 µg/L for copper, 63 µg/L for zinc, 107 µg/L for cobalt, 145 µg/L for cadmium, and 369 µg/L for nickel. Slightly higher 28-day EC50s of 16 µg/L for copper, 192 µg/L for zinc, 172 µg/L for cobalt, 185 µg/L for cadmium, and 404 µg/L for nickel exposures and were estimated based on reductions in the total number of live developed and undeveloped offspring. These sensitive and chronic sub-lethal toxicity estimates help fill the knowledge gap related to metal effects on cnidarians over longer exposure periods, and this newly-developed bioassay may provide a much needed tool for ecotoxicological risk assessment relevant to tropical marine environments.

  3. The HEX1 gene of Fusarium graminearum is required for fungal asexual reproduction and pathogenesis and for efficient viral RNA accumulation of Fusarium graminearum virus 1.

    Science.gov (United States)

    Son, Moonil; Lee, Kyung-Mi; Yu, Jisuk; Kang, Minji; Park, Jin Man; Kwon, Sun-Jung; Kim, Kook-Hyung

    2013-09-01

    The accumulation of viral RNA depends on many host cellular factors. The hexagonal peroxisome (Hex1) protein is a fungal protein that is highly expressed when the DK21 strain of Fusarium graminearum virus 1 (FgV1) infects its host, and Hex1 affects the accumulation of FgV1 RNA. The Hex1 protein is the major constituent of the Woronin body (WB), which is a peroxisome-derived electron-dense core organelle that seals the septal pore in response to hyphal wounding. To clarify the role of Hex1 and the WB in the relationship between FgV1 and Fusarium graminearum, we generated targeted gene deletion and overexpression mutants. Although neither HEX1 gene deletion nor overexpression substantially affected vegetative growth, both changes reduced the production of asexual spores and reduced virulence on wheat spikelets in the absence of FgV1 infection. However, the vegetative growth of deletion and overexpression mutants was increased and decreased, respectively, upon FgV1 infection compared to that of an FgV1-infected wild-type isolate. Viral RNA accumulation was significantly decreased in deletion mutants but was significantly increased in overexpression mutants compared to the viral RNA accumulation in the virus-infected wild-type control. Overall, these data indicate that the HEX1 gene plays a direct role in the asexual reproduction and virulence of F. graminearum and facilitates viral RNA accumulation in the FgV1-infected host fungus.

  4. Mutation of FVS1, encoding a protein with a sterile alpha motif domain, affects asexual reproduction in the fungal plant pathogen Fusarium oxysporum.

    Science.gov (United States)

    Iida, Yuichiro; Fujiwara, Kazuki; Yoshioka, Yosuke; Tsuge, Takashi

    2014-02-01

    Fusarium oxysporum produces three kinds of asexual spores: microconidia, macroconidia and chlamydospores. We previously analysed expressed sequence tags during vegetative growth and conidiation in F. oxysporum and found 42 genes that were markedly upregulated during conidiation compared to vegetative growth. One of the genes, FVS1, encodes a protein with a sterile alpha motif (SAM) domain, which functions in protein-protein interactions that are involved in transcriptional or post-transcriptional regulation and signal transduction. Here, we made FVS1-disrupted mutants from the melon wilt pathogen F. oxysporum f. sp. melonis. Although the mutants produced all three kinds of asexual spores with normal morphology, they formed markedly fewer microconidia and macroconidia than the wild type. The mutants appeared to have a defect in the development of the conidiogenesis cells, conidiophores and phialides, required for the formation of microconidia and macroconidia. In contrast, chlamydospore formation was dramatically promoted in the mutants. The growth rates of the mutants on media were slightly reduced, indicating that FVS1 is also involved in, but not essential for, vegetative growth. We also observed that mutation of FVS1 caused defects in conidial germination and virulence, suggesting that the Fvs1 has pleiotropic functions in F. oxysporum.

  5. Co-evolutionary patterns and diversification of ant-fungus associations in the asexual fungus-farming ant Mycocepurus smithii in Panama.

    Science.gov (United States)

    Kellner, K; Fernández-Marín, H; Ishak, H D; Sen, R; Linksvayer, T A; Mueller, U G

    2013-06-01

    Partner fidelity through vertical symbiont transmission is thought to be the primary mechanism stabilizing cooperation in the mutualism between fungus-farming (attine) ants and their cultivated fungal symbionts. An alternate or additional mechanism could be adaptive partner or symbiont choice mediating horizontal cultivar transmission or de novo domestication of free-living fungi. Using microsatellite genotyping for the attine ant Mycocepurus smithii and ITS rDNA sequencing for fungal cultivars, we provide the first detailed population genetic analysis of local ant-fungus associations to test for the relative importance of vertical vs. horizontal transmission in a single attine species. M. smithii is the only known asexual attine ant, and it is furthermore exceptional because it cultivates a far greater cultivar diversity than any other attine ant. Cultivar switching could permit the ants to re-acquire cultivars after garden loss, to purge inferior cultivars that are locally mal-adapted or that accumulated deleterious mutations under long-term asexuality. Compared to other attine ants, symbiont choice and local adaptation of ant-fungus combinations may play a more important role than partner-fidelity feedback in the co-evolutionary process of M. smithii and its fungal symbionts.