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Sample records for spontaneous germinal vesicle

  1. Spontaneous Vesicle Recycling in the Synaptic Bouton

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    Sven eTruckenbrodt

    2014-12-01

    Full Text Available The trigger for synaptic vesicle exocytosis is Ca2+, which enters the synaptic bouton following action potential stimulation. However, spontaneous release of neurotransmitter also occurs in the absence of stimulation in virtually all synaptic boutons. It has long been thought that this represents exocytosis driven by fluctuations in local Ca2+ levels. The vesicles responding to these fluctuations are thought to be the same ones that release upon stimulation, albeit potentially triggered by different Ca2+ sensors. This view has been challenged by several recent works, which have suggested that spontaneous release is driven by a separate pool of synaptic vesicles. Numerous articles appeared during the last few years in support of each of these hypotheses, and it has been challenging to bring them into accord. We speculate here on the origins of this controversy, and propose a solution that is related to developmental effects. Constitutive membrane traffic, needed for the biogenesis of vesicles and synapses, is responsible for high levels of spontaneous membrane fusion in young neurons, probably independent of Ca2+. The vesicles releasing spontaneously in such neurons are not related to other synaptic vesicle pools and may represent constitutively releasing vesicles (CRVs rather than bona fide synaptic vesicles. In mature neurons, constitutive traffic is much dampened, and the few remaining spontaneous release events probably represent bona fide spontaneously releasing synaptic vesicles (SRSVs responding to Ca2+ fluctuations, along with a handful of CRVs that participate in synaptic vesicle turnover.

  2. Spontaneous charged lipid transfer between lipid vesicles.

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    Richens, Joanna L; Tyler, Arwen I I; Barriga, Hanna M G; Bramble, Jonathan P; Law, Robert V; Brooks, Nicholas J; Seddon, John M; Ces, Oscar; O'Shea, Paul

    2017-10-03

    An assay to study the spontaneous charged lipid transfer between lipid vesicles is described. A donor/acceptor vesicle system is employed, where neutrally charged acceptor vesicles are fluorescently labelled with the electrostatic membrane probe Fluoresceinphosphatidylethanolamine (FPE). Upon addition of charged donor vesicles, transfer of negatively charged lipid occurs, resulting in a fluorescently detectable change in the membrane potential of the acceptor vesicles. Using this approach we have studied the transfer properties of a range of lipids, varying both the headgroup and the chain length. At the low vesicle concentrations chosen, the transfer follows a first-order process where lipid monomers are transferred presumably through the aqueous solution phase from donor to acceptor vesicle. The rate of transfer decreases with increasing chain length which is consistent with energy models previously reported for lipid monomer vesicle interactions. Our assay improves on existing methods allowing the study of a range of unmodified lipids, continuous monitoring of transfer and simplified experimental procedures.

  3. Spontaneous transfer of gangliotetraosylceramide between phospholipid vesicles

    International Nuclear Information System (INIS)

    Brown, R.E.; Sugar, I.P.; Thompson, T.E.

    1985-01-01

    The transfer kinetics of the neutral glycosphingolipid gangliotetraosylceramide (asialo-GM1) were investigated by monitoring tritiated asialo-GM1 movement from donor to acceptor vesicles. Two different methods were employed to separate donor and acceptor vesicles at desired time intervals. In one method, a negative charge was imparted to dipalmitoylphosphatidylcholine donor vesicles by including 10 mol% dipalmitoylphosphatidic acid. Donors were separated from neutral dipalmitoylphosphatidylcholine acceptor vesicles by ion-exchange chromatography. In the other method, small, unilamellar donor vesicles and large, unilamellar acceptor vesicles were coincubated at 45 degrees C and then separated at desired time intervals by molecular sieve chromatography. The majority of asialo-GM1 transfer to acceptor vesicles occurred as a slow first-order process with a half-time of about 24 days assuming that the relative concentration of asialo-GM1 in the phospholipid matrix was identical in each half of the donor bilayer and that no glycolipid flip-flop occurred. Asialo-GM1 net transfer was calculated relative to that of [ 14 C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. A nearly identical transfer half-time was obtained when the phospholipid matrix was changed from dipalmitoylphosphatidylcholine to palmitoyloleoylphosphatidylcholine. Varying the acceptor vesicle concentration did not significantly alter the asialo-GM1 transfer half-time. This result is consistent with a transfer mechanism involving diffusion of glycolipid through the aqueous phase rather than movement of glycolipid following formation of collisional complexes between donor and acceptor vesicles. (Abstract Truncated)

  4. Maturation arrest of human oocytes at germinal vesicle stage

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    Zhi Qin Chen

    2010-01-01

    Full Text Available Maturation arrest of human oocytes may occur at various stages of the cell cycle. A total failure of human oocytes to complete meiosis is rarely observed during assisted conception cycles. We describe here a case of infertile couples for whom all oocytes repeatedly failed to mature at germinal vesicle (GV stage during in vitro fertilization/Intra cytoplasmic sperm injection (IVF/ICSI. The patient underwent controlled ovarian stimulation followed by oocyte retrieval and IVF/ICSI. The oocytes were stripped off cumulus cells prior to the ICSI procedure and their maturity status was defined. The oocyte maturation was repeatedly arrested at the GV. Oocyte maturation arrest may be the cause of infertility in this couple. The recognition of oocyte maturation arrest as a specific medical condition may contribute to the characterization of the currently known as "oocyte factor." The cellular and genetic mechanisms causing oocyte maturation arrest should be the subject for further investigation.

  5. In Vitro Maturation and Embryo Development to blastocyst Mouse Germinal Vesicle Oocytes after Vitrification

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    M Nikseresht

    2013-05-01

    Full Text Available Abstract Background & aim: Vitrification is a simple and ultra rapid technique for the conservation of fertility. Improving pregnancy rate associate with the use of cryopreserved oocytes would be an important advanced in human assisted reproductive technology (ART. The purpose of this study was to evaluate survival, oocytes maturation and embryo development to the blastocyst stage after vitrification of oocytes germinal vesicle-stage and multi stage Methods: In the present experimental study, germinal vesicle oocytes with or without cumulus cells were transferred to vitrification solution containing 30% (v/v ethylene glycol, 18% (w/v Ficoll-70, and 0.3 M sucrose, either by single step or in a step-wise way. After vitrification and storage in liquid nitrogen, the oocytes were thawed and washed twice in culture medium TCM119, and then subjected to in vitro maturation, fertilization, and culture. Data analysis was performed by using One-way variance and Tukey tests. Results: Oocytes survival, metaphase 2 stage oocyte maturation, fertilization and embryo formed blastocyst in vitrification methods multistage were significantly higher than the single step procedure (P<0/05 Conclusion: The Germinal vesicle stage oocytes vitrified with cumulus cells and stepwise procedure had positive effect on the survival, maturation and developmental rate on blastocyst compared to oocytes without cumulus cell and single step procedure. Key words: Germinal Vesicle Oocyte, Blastocyst, Vitrification, Ethylene glycol

  6. Spontaneous transfer of ganglioside GM1 between phospholipid vesicles

    International Nuclear Information System (INIS)

    Brown, R.E.; Thompson, T.E.

    1987-01-01

    The transfer kinetics of the negatively charged glycosphingolipid II 3 -N-acetylneuraminosyl-gangliotetraosylceramide (GM 1 ) were investigated by monitoring tritiated GM 1 movement between donor and acceptor vesicles. After appropriate incubation times at 45 0 C, donor and acceptor vesicles were separated by molecular sieve chromatography. Donors were small unilamellar vesicles produced by sonication, whereas acceptors were large unilamellar vesicles produced by either fusion or ethanol injection. Initial GM 1 transfer to acceptors followed first-order kinetics with a half-time of about 40 h assuming that GM 1 is present in equal mole fractions in the exterior and interior surfaces of the donor vesicle bilayer and that no glycolipid flip-flop occurs. GM 1 net transfer was calculated relative to that of [ 14 C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. Factors affecting the GM 1 interbilayer transfer rate included phospholipid matrix composition, initial GM 1 concentration in donor vesicles, and the GM 1 distribution in donor vesicles with respect to total lipid symmetry. The findings provide evidence that GM 1 is molecularly dispersed at low concentrations within liquid-crystalline phospholipid bilayers

  7. Ganglioside GM1 spontaneous transfer between phospholipid vesicles

    International Nuclear Information System (INIS)

    Brown, R.E.; Sugar, I.P.; Thompson, T.E.

    1986-01-01

    The transfer kinetics of the monosiaylated glycosphingolipid, GM 1 , between different size phospholipid vesicles was measured using molecular sieve chromatography. At desired time intervals, small unilamellar donor vesicles were separated from large unilamellar acceptor vesicles by elution from a Sephacryl S-500 column [ 3 H]-GM 1 net transfer was calculated relative to [ 14 C]-cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. The initial GM 1 transfer rate between 1-palmitoyl-2-oleoyl phosphatidylcholine vesicles at 45 0 C deviated slightly from first order kinetics and possessed a half time of 3.6 days. This transfer half time is an order of magnitude shorter than that observed from the desiaylated derivative of GM 1 . The transfer kinetics are consistent with the authors recent electron microscopic results suggesting a molecular distribution of GM 1 in liquid-crystalline phosphatidylcholine bilayers

  8. The effect of spontaneous curvature on a two-phase vesicle

    International Nuclear Information System (INIS)

    Cox, Geoffrey; Lowengrub, John

    2015-01-01

    Vesicles are membrane-bound structures commonly known for their roles in cellular transport and the shape of a vesicle is determined by its surrounding membrane (lipid bilayer). When the membrane is composed of different lipids, it is natural for the lipids of similar molecular structure to migrate towards one another (via spinodal decomposition), creating a multi-phase vesicle. In this article, we consider a two-phase vesicle model which is driven by nature's propensity to maintain a minimal state of elastic energy. The model assumes a continuum limit, thereby treating the membrane as a closed three-dimensional surface. The main purpose of this study is to reveal the complexity of the Helfrich two-phase vesicle model with non-zero spontaneous curvature and provide further evidence to support the relevance of spontaneous curvature as a modelling parameter. In this paper, we illustrate the complexity of the Helfrich two-phase model by providing multiple examples of undocumented solutions and energy hysteresis. We also investigate the influence of spontaneous curvature on morphological effects and membrane phenomena such as budding and fusion. (paper)

  9. Spontaneous vesicle phase formation by pseudogemini surfactants in aqueous solutions.

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    Sun, Nan; Shi, Lijuan; Lu, Fei; Xie, Shuting; Zheng, Liqiang

    2014-08-14

    The phase behavior of a kind of pseudogemini surfactant in aqueous solutions, formed by the mixture of sodium dodecyl benzene sulfonate (SDBS) and butane-1,4-bis (methylimidazolium bromide) ([mim-C4-mim]Br2) or butane-1,4-bis(methylpyrrolidinium bromide) ([mpy-C4-mpy]Br2) in a molar ratio of 2 : 1, is reported in the present work. When [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 is mixed with SDBS in aqueous solutions, one cationic [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 molecule "bridges" two SDBS molecules by noncovalent interactions (e.g. electrostatic, π-π stacking, and σ-π interactions), behaving like a pseudogemini surfactant. Vesicles can be formed by this kind of pseudogemini surfactant, determined by freeze-fracture transmission electron microscopy (FF-TEM) or cryogenic-transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). The mixed system of sodium dodecyl sulfate (SDS) with [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 was also constructed, and only micelles were observed. We infer that a pseudogemini surfactant is formed under the synergic effect of electrostatic, π-π stacking, and σ-π interactions in the SDBS/[mim-C4-mim]Br2/H2O system, while electrostatic attraction and hydrophobic interactions may provide the directional force for vesicle formation in the SDBS/[mpy-C4-mpy]Br2/H2O system.

  10. Spontaneous Vesicle Self-Assembly: A Mesoscopic View of Membrane Dynamics

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    Shillcock, J. C.

    2012-01-01

    Amphiphilic vesicles are ubiquitous in living cells and industrially interesting as drug delivery vehicles. Vesicle self-assembly proceeds rapidly from nanometer to micrometer length scales and is too fast to image experimentally but too slow for molecular dynamics simulations. Here, we use...... parallel dissipative particle dynamics (DPD) to follow spontaneous vesicle self-assembly for up to 445 mu s with near-molecular resolution. The mean mass and radius of gyration of growing amphiphilic clusters obey power laws with exponents of 0.85 +/- 0.03 and 0.41 +/- 0.02, respectively. We show that DPD...... provides a computational window onto fluid dynamics on scales unreachable by other explicit-solvent simulations....

  11. Vitrification of human germinal vesicle oocytes; before or after in vitro maturation?

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    Evangelia Kasapi

    2017-03-01

    Full Text Available Background The use of immature oocytes derived from stimulated cycles could be of great importance, particularly for urgent fertility preservation cases. The current study aimed to determine whether in vitro maturation (IVM was more successful before or after vitrification of these oocytes. Materials and Methods This prospective study was performed in a private in vitro fertilization (IVF center. We collected 318 germinal vesicle (GV oocytes from 104 stimulated oocyte donation cycles. Oocytes were divided into two groups according to whether vitrification was applied at the GV stage (group 1 or in vitro matured to the metaphase II (MII stage and then vitrified (group 2. In the control group (group 3, oocytes were in vitro matured without vitrification. In all three groups, we assessed survival rate after warming, maturation rate, and MII-spindle/chromosome configurations. The chi-square test was used to compare rates between the three groups. Statistical significance was defined at P<0.05 and we used Bonferroni criterion to assess statistical significance regarding the various pairs of groups. The Statistical Package for the Social Sciences version 17.0 was used to perform statistical analysis. Results There was no significant difference in the survival rate after vitrification and warming of GV (93.5% and MII oocytes (90.8%. A significantly higher maturation rate occurred when IVM was performed before vitrification (82.9% compared to after vitrification (51%. There was no significant difference in the incidence of normal spindle/ chromosome configurations among warmed oocytes matured in vitro before (50.0% or after (41.2% vitrification. However, a higher incidence of normal spindle/chromosome configurations existed in the in vitro matured oocytes which were not subjected to vitrification (fresh oocytes, 77.9%. Conclusion In stimulated cycles, vitrification of in vitro matured MII oocytes rather than GV oocytes seems to be more efficient. This

  12. Reprogramming of round spermatids by the germinal vesicle cytoplasm in mice.

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    Peng-Cheng Kong

    Full Text Available The birthrate following round spermatid injection (ROSI remains low in current and evidence suggests that factors in the germinal vesicle (GV cytoplasm and certain substances in the GV such as the nucleolus might be responsible for genomic reprogramming and embryonic development. However, little is known whether the reprogramming factors in GV oocyte cytoplasm and/or nucleolus in GV are beneficial to the reprogramming of round spermatids and development of ROSI embryos. Here, round spermatids were treated with GV cytolysates and injected this round spermatid alone or co-injected with GV oocyte nucleolus into mature metaphase II oocytes. Subsequent embryonic development was assessed morphologically and by Oct4 expression in blastocysts. There was no significant difference between experimental groups at the zygote to four-cell development stages. Blastocysts derived from oocytes which were injected with cytolysate treated-round spermatid alone or co-injected with nucleoli injection yielded 63.6% and 70.3% high quality embryos, respectively; comparable to blastocysts derived by intracytoplasmic sperm injection (ICSI, but higher than these oocytes which were co-injected with lysis buffer-treated round spermatids and nucleoli or injected with the lysis buffer-treated round spermatids alone. Furthermore, the proportion of live offspring resulting from oocytes which were co-injected with cytolysate treated-round spermatids and nucleoli or injected with cytolysate treated-round spermatids alone was higher than those were injected with lysis buffer treated-round spermaids, but comparable with the ICSI group. Our results demonstrate that factors from the GV cytoplasm improve round spermatid reprogramming, and while injection of the extra nucleolus does not obviously improve reprogramming its potential contribution, although which cannot be definitively excluded. Thus, some reprogramming factors are evidently present in GV oocyte cytoplasm and could

  13. Proteolytic Activity of the 26S Proteasome is required for the Meiotic Resumption, Germinal Vesicle Breakdown and Cumulus Expansion of Porcine Cumulus-Oocyte Complexes Matured In Vitro

    Czech Academy of Sciences Publication Activity Database

    Yi, Y. J.; Nagyová, Eva; Manandhar, G.; Procházka, Radek; Šutovsky, M.; Park, C. S.; Šutovský, P.

    2008-01-01

    Roč. 78, - (2008), s. 115-126 ISSN 0006-3363 R&D Projects: GA ČR GA305/05/0960 Institutional research plan: CEZ:AV0Z50450515 Keywords : cumulus expansion * FSH * germinal vesicle breakdown Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.469, year: 2008

  14. The Sea Cucumber Body Wall Extract Promoted in Vitro Maturation of NMRI Mice Follicles at Germinal Vesicle Stage

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    Mitra Khalilzadeh

    2016-07-01

    Full Text Available Background IVM (in vitro maturation appear to be certified high pregnancy outcome. Therefore, attempt to find an appropriate culture system using natural products for increasing developmental competencies fascinating. Objectives This experiment is aimed to evaluate the effect of sea cucumber methanol extract on in vitro maturation of immature mouse oocyte. Methods In this experimental study, Preantral follicles at germinal vesicle stage were collected from 24 - 26 days NMRI female mouse ovaries and transferred to IVM medium supplemented with different concentration of sea cucumber methanol extract (5, 10, 20, 30 µg/mL. Antioxidant capacity of sea cucumber extract was evaluated using DPPH (2, 2-diphenyl-1-picrylhydrazyl assay. Further, oocyte maturation and TNF-α expression were recorded till day 10th. Data were analyzed by one-way analysis of variance (ANOVA through SPSS 16. Results The percentage of arrested oocyte at germinal vesicle stage in the control group was significantly (P < 0.05 higher than treated group (20 µg/mL. There were significant (P < 0.01 differences in percentage of maturated oocyte to metaphase II (MII stage between treated and control group. DPPH radical scavenging capacity and reduction of TNF-α expression in treated oocyte demonstrated that sea cucumber increased rate of oocyte maturation. In addition, the treated oocyte (20 µg/mL achieved the highest percentage of MII stage. Conclusions It was concluded that the sea cucumber extract with optimum concentration can improve oocyte maturation. Sea cucumber extract treatment can be suggested as a novel therapeutic strategy to be used in infertility modality in the future.

  15. Interactions Between SNAP-25 and Synaptotagmin-1 Are Involved in Vesicle Priming, Clamping Spontaneous and Stimulating Evoked Neurotransmission

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    Schupp, Melanie; Malsam, Jörg; Ruiter, Marvin

    2016-01-01

    between region I (vesicle priming) and region II (evoked release). Spontaneous release was disinhibited by region I mutations and found to correlate with defective complexin (Cpx) clamping in an in vitro fusion assay, pointing to an interdependent role of synaptotagmin and Cpx in release clamping...... triggering, depend on direct SNARE complex interaction. SIGNIFICANCE STATEMENT: The function of synaptotagmin-1 (syt-1):soluble NSF attachment protein receptor (SNARE) interactions during neurotransmission remains unclear. We mutated SNAP-25 within the recently identified region I and region II...... was disinhibited by region I mutation and found to correlate with defective complexin (Cpx) clamping in vitro, pointing to an interdependent role of synaptotagmin and Cpx in release clamping. Therefore, vesicle priming, clamping spontaneous release, and eliciting evoked release are three different functions of syt...

  16. Accessory nuclei revisited: the translocation of snRNPs from the germinal vesicle to the periphery of the future embryo.

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    Biliński, Szczepan M; Kloc, Małgorzata

    2002-03-01

    Oocytes of certain insects contain peculiar organelles termed accessory nuclei (AN). These organelles originate by budding off from the envelope of the oocyte nucleus and contain 1-2 dense inclusions immersed in a translucent ground substance. We have demonstrated that in the wasp Vespula germanica each inclusion consists of two elements: a spherical body, and a hemispherical structure composed of numerous 20-30 nm particles. Immunoelectron microscopy and whole-mount in situ hybridization have shown that the inclusions contain AgNOR-staining proteins, p80-coilin, Sm proteins, and small nuclear RNAs (snRNAs). These results indicate that the inclusions and hemispherical structures are homologous to Cajal bodies and B-snurposomes of Xenopus germinal vesicles, respectively. During previtellogenesis, AN (together with their Cajal bodies) migrate to the cortical ooplasm of the oocyte where they reside at least until the onset of embryogenesis. We suggest that AN are vehicles for the transport and localization of snRNPs to the periphery of the oocyte, i.e., to the region where the blastoderm of the embryo develops and where there is a requirement for a high concentration of RNA-processing factors.

  17. In Vitro Maturation and Fertilization of Cryopreserved Germinal Vesicle Stage Oocytes in NMRI Mice, Using Ethylene Glycol and DMSO

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    O Mayahi

    2011-10-01

    Full Text Available Background & Aim: Cryopreservation of oocytes is an essential part of reproductive biotechnology. The objective of the present study was to investigate the effects of exposure to combination of cryoprotectants and vitrification on immature mouse oocytes with or without cumulus cells. Methods: This was an experimental study conducted at Yasouj University of Medical Sciences in 2010. Immature oocytes with and without cumulus cells were isolated from ovaries of mice 4-6 weeks of age. They were vitrified in conventional straw using ethylene glycol (EG, dimethyl sulfoxide (DMSO and sucrose as vitrification solution or exposed to vitrification solution without subjected to liquid nitrogen. After warming, oocytes were assessed for nuclear maturation and fertilization. The collected data were analyzed with one-way ANOVA and Tukey test. Results: Survival and fertilization rates in vitrified oocytes with cumulus cells were significantly lower than the control group (p<0.05. Maturation rates in exposure groups were significantly lower than the vitrified and control groups (p<0.05. The fertilization rate increased significantly in all experiment and control groups with cumulus cells in comparison with denuded oocytes (p<0.05. Conclusion: Germinal vesicle stage oocytes in the presence or absence of cumulus cells can be vitrified successfully. Exposure to cryoprotectants can decrease the developmental competence of GV oocytes. Presence of cumulus cells can increase the fertilization rate in IVF procedure.

  18. Nucleoli from two-cell embryos support the development of enucleolated germinal vesicle oocytes in the pig.

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    Kyogoku, Hirohisa; Ogushi, Sugako; Miyano, Takashi

    2012-11-01

    Recent research has shown that nucleoli of oocytes at the germinal vesicle (GV) stage (GV nucleoli) are not necessary for oocyte maturation but are essential for early embryonic development. Nucleoli of 2-cell embryos (2-cell nucleoli) have morphology similar to that of nucleoli in oocytes at the GV stage. In this study, we examined the ability of 2-cell nucleoli to substitute for GV nucleoli in terms of supporting early embryonic development by nucleolus aspiration (enucleolation) and transfer into metaphase II (MII) oocytes or 2-cell embryos that were derived from enucleolated oocytes at the GV stage in the pig. When 2-cell embryos were centrifuged to move the lipid droplets to one side of the blastomere, multiple nucleoli in the nucleus fused into a single nucleolus. The nucleoli were then aspirated from the 2-cell embryos by micromanipulation. The injection of 2-cell nucleoli to GV enucleolated oocytes at the MII stage rescued the embryos from the early embryonic arrest, and the resulting oocytes developed to blastocysts. However, the injection of 2-cell and GV nucleoli to 2-cell embryos derived from GV enucleolated oocytes rarely restored the development to blastocysts. These results indicate that 2-cell nucleoli support early embryonic development as GV nucleoli and that the presence of nucleoli is essential for pig embryos before the 2-cell stage.

  19. The effects of platelet lysate on maturation, fertilization and embryo development of NMRI mouse oocytes at germinal vesicle stage.

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    Pazoki, Hassan; Eimani, Hussein; Farokhi, Farah; Shahverdi, Abdol-Hossein; Tahaei, Leila Sadat

    2016-04-01

    Improving in vitro maturation could increase the rate of pregnancy from oocytes matured in vitro. Consequently, patients will be prevented from using gonadotropin with its related side effects. In this study, the maturation medium was enriched by platelet lysate (PL), then maturation and subsequent developments were monitored. Oocytes at germinal vesicle stage with cumulus cells (cumulus-oocyte complex) and without cumulus cells (denuded oocytes) were obtained from mature female mice. The maturation medium was enriched by 5 and 10 % PL and 5 % PL + 5 % fetal bovine serum (FBS) as experimental groups; the control groups' media consisted of 5 and 10 % FBS. After 18 h, the matured oocytes were collected and, after fertilization, subsequent development was monitored. The rates of maturation, fertilization and 2-cell embryo development for the denuded oocyte groups in experimental media 5 % PL and 5 % PL + 5 % FBS were significantly higher than those of the control groups ( P platelet lysate could improve the maturation rate in the absence of granulosa cells compared to media with FBS. This extract also had positive effects on fertilization and embryo development.

  20. Meiotic maturation and developmental capability of ovine oocytes at germinal vesicle stage following vitrification using different cryodevices.

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    Quan, Guo Bo; Wu, Guo Quan; Wang, Ya Jing; Ma, Yuan; Lv, Chun Rong; Hong, Qiong Hua

    2016-02-01

    In order to assess effects of vitrification on ovine oocytes at the germinal vesicle (GV) stage, the conventional plastic straw (CS), the open-pulled straw (OPS), and Cryoloop were used to vitrify ovine oocytes. Oocytes were randomly divided into five groups: (1) Control; (2) Oocytes exposed to vitrification and dilution solutions without any cryopreservation (toxicity); (3) Oocytes vitrified using CS (CS); (4) Oocytes vitrified using OPS (OPS), and (5) Oocytes vitrified using Cryoloop (Cryoloop). The viability, cumulus cell expansion, nuclear maturation after in vitro maturation (IVM), and developmental capability of vitrified oocytes following parthenogenetic activation (PA) or in vitro fertilization (IVF) were assessed. The pretreatment in the vitrification and dilution solutions without any freezing or thawing did not adversely influence oocytes. The viability of vitrified oocytes were significantly declined compared to unfrozen oocytes (P straws or Cryoloop was significantly higher than that in the CS group (P plastic straws was significantly less than those of the other freezing groups (P straws. However, the cleavage rate of vitrified oocytes in the CS group was significantly less than that in the OPS or Cryoloop group (P plastic straw developed to the blastocyst stage following IVF. There was no significant difference existing between OPS and Cryoloop with respect to the blastocyst rate. After staining with cFDA and PI, cumulus cells surrounding oocytes were partly damaged by vitrification and thawing while the membrane of vitrified oocyte still remained intact. In conclusion, vitrification can seriously damage ovine immature oocytes and cumulus cells surrounding oocytes, which may subsequently affect their developmental capability. Finally, this study further proves that increasing the freezing and thawing velocity benefits survival of vitrified immature oocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Meiosis, egg activation, and nuclear envelope breakdown are differentially reliant on Ca2+, whereas germinal vesicle breakdown is Ca2+ independent in the mouse oocyte

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    Tombes, R. M.; Simerly, C.; Borisy, G. G.; Schatten, G.

    1992-01-01

    During early development, intracellular Ca2+ mobilization is not only essential for fertilization, but has also been implicated during other meiotic and mitotic events, such as germinal vesicle breakdown (GVBD) and nuclear envelope breakdown (NEBD). In this study, the roles of intracellular and extracellular Ca2+ were examined during meiotic maturation and reinitiation at parthenogenetic activation and during first mitosis in a single species using the same methodologies. Cumulus-free metaphase II mouse oocytes immediately resumed anaphase upon the induction of a large, transient Ca2+ elevation. This resumption of meiosis and associated events, such as cortical granule discharge, were not sensitive to extracellular Ca2+ removal, but were blocked by intracellular Ca2+ chelators. In contrast, meiosis I was dependent on external Ca2+; in its absence, the formation and function of the first meiotic spindle was delayed, the first polar body did not form and an interphase-like state was induced. GVBD was not dependent on external Ca2+ and showed no associated Ca2+ changes. NEBD at first mitosis in fertilized eggs, on the other hand, was frequently, but not always associated with a brief Ca2+ transient and was dependent on Ca2+ mobilization. We conclude that GVBD is Ca2+ independent, but that the dependence of NEBD on Ca2+ suggests regulation by more than one pathway. As cells develop from Ca(2+)-independent germinal vesicle oocytes to internal Ca(2+)-dependent pronuclear eggs, internal Ca2+ pools increase by approximately fourfold.

  2. Spontaneous Vesicle Fusion Is Differentially Regulated at Cholinergic and GABAergic Synapses

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    Haowen Liu

    2018-02-01

    Full Text Available The locomotion of C. elegans is balanced by excitatory and inhibitory neurotransmitter release at neuromuscular junctions. However, the molecular mechanisms that maintain the balance of synaptic transmission remain enigmatic. Here, we investigated the function of voltage-gated Ca2+ channels in triggering spontaneous release at cholinergic and GABAergic synapses. Recordings of the miniature excitatory/inhibitory postsynaptic currents (mEPSCs and mIPSCs, respectively showed that UNC-2/CaV2 and EGL-19/CaV1 channels are the two major triggers for spontaneous release. Notably, however, Ca2+-independent spontaneous release was observed at GABAergic but not cholinergic synapses. Functional screening led to the identification of hypomorphic unc-64/Syntaxin-1A and snb-1/VAMP2 mutants in which mEPSCs are severely impaired, whereas mIPSCs remain unaltered, indicating differential regulation of these currents at cholinergic and GABAergic synapses. Moreover, Ca2+-independent spontaneous GABA release was nearly abolished in the hypomorphic unc-64 and snb-1 mutants, suggesting distinct mechanisms for Ca2+-dependent and Ca2+-independent spontaneous release.

  3. Time-lapse cinematography study of the germinal vesicle behaviour in mouse primary oocytes treated with activators of protein kinases A and C.

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    Alexandre, H; Mulnard, J

    1988-12-01

    A passive erratic movement of the germinal vesicle (GV), already visible in small incompetent oocytes, is followed by an active scalloping of the nuclear membrane soon before GV breakdown (GVBD) in cultured competent oocytes. Maturation can be inhibited by activators of protein kinase A (PK-A) and protein kinase C (PK-C). Our time-lapse cinematography analysis allowed us to describe an unexpected behaviour of the GV when PK-C, but not PK-A, is activated: GV undergoes a displacement toward the cortex according to the same biological clock which triggers the programmed translocation of the spindle in control oocytes. It is concluded that, when oocytes become committed to undergo maturation, the cytoplasm acquires a PK-A-controlled "centrifugal displacement property" which is not restricted to the spindle.

  4. Spontaneous formation of small unilamellar vesicles by pH jump: A pH gradient across the bilayer membrane as the driving force

    International Nuclear Information System (INIS)

    Hauser, H.; Mantsch, H.H.; Casal, H.L.

    1990-01-01

    31 P NMR and infrared spectroscopic methods have been used to study the formation of small unilamellar vesicles by the pH-jump method. It is shown that increasing the pH of different lamellar phospholipid dispersions (phosphatidic acids and phosphatidylserines) induces a pH gradient. This pH gradient is estimated to be 4 ± 1 pH units, and its direction is such that the inner monolayer of the vesicles is at lower pH. There is spectroscopic evidence for tighter packing of the lipid hydrocarbon chains in the inner monolayer, probably due to the constraints imposed by the high curvature of the small vesicles formed. These results are discussed in terms of the driving force of the spontaneous vesiculation

  5. Chronic exposure to a low concentration of bisphenol A during follicle culture affects the epigenetic status of germinal vesicles and metaphase II oocytes.

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    Trapphoff, Tom; Heiligentag, Martyna; El Hajj, Nady; Haaf, Thomas; Eichenlaub-Ritter, Ursula

    2013-12-01

    To determine whether exposure to low concentrations of the endocrine disrupting chemical bisphenol A (BPA) during follicle culture and oocyte growth alters the methylation status of differentially methylated regions (DMRs) of imprinted genes and histone posttranslational modification patterns in mammalian oocytes. Comparative and control study. Experimental laboratory. C57/Bl6JxCBA/Ca mice. Exposure of oocytes to 3 nM or 300 nM BPA during follicle culture from preantral to antral stage. Methylation status of DMRs of maternally imprinted (Snrpn, Igf2r, and Mest) and paternally imprinted gene(s) (H19) in mouse germinal vesicle oocytes; trimethylation of histone H3K9, acetylation of histone H4K12, and distance between centromeres of sister chromatids in metaphase II oocytes. Exposure to 3 nM BPA was associated with slightly accelerated follicle development, statistically significant increases in allele methylation errors in DMRs of maternally imprinted genes, and statistically significant decreases in histone H3K9 trimethylation and interkinetochore distance. The disturbances in oocyte genomic imprinting and modification of posttranslational histone and centromere architecture provide the first link between low BPA exposures and induction of epigenetic changes that may contribute to chromosome congression failures and meiotic errors, and to altered gene expression that might affect health of the offspring. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Developmental Competence of Vitrified-Warmed Bovine Oocytes at the Germinal-Vesicle Stage is Improved by Cyclic Adenosine Monophosphate Modulators during In Vitro Maturation.

    Directory of Open Access Journals (Sweden)

    Kenji Ezoe

    Full Text Available Cryopreservation of mature oocytes and embryos has provided numerous benefits in reproductive medicine. Although successful cryopreservation of germinal-vesicle stage (GV oocytes holds promise for further advances in reproductive biology and clinical embryology fields, reports regarding cryopreservation of immature oocytes are limited. Oocyte survival and maturation rates have improved since vitrification is being performed at the GV stage, but the subsequent developmental competence of GV oocytes is still low. The purpose of this study was to evaluate the effects of supplementation of the maturation medium with cyclic adenosine monophosphate (cAMP modulators on the developmental competence of vitrified-warmed GV bovine oocytes. GV oocytes were vitrified-warmed and cultured to allow for oocyte maturation, and then parthenogenetically activated or fertilized in vitro. Our results indicate that addition of a cAMP modulator forskolin (FSK or 3-isobutyl-1-methylxanthine (IBMX to the maturation medium significantly improved the developmental competence of vitrified-warmed GV oocytes. We also demonstrated that vitrification of GV oocytes led to a decline in cAMP levels and maturation-promoting factor (MPF activity in the oocytes during the initial and final phases of maturation, respectively. Nevertheless, the addition of FSK or IBMX to the maturation medium significantly elevated cAMP levels and MPF activity during IVM. Taken together, our results suggest that the cryopreservation-associated meiotic and developmental abnormalities observed in GV oocytes may be ameliorated by an artificial increase in cAMP levels during maturation culture after warming.

  7. Comparison of Different Vitrification Procedures on Developmental Competence of Mouse Germinal Vesicle Oocytes in the Presence or Absence of Cumulus Cells

    Directory of Open Access Journals (Sweden)

    Mojdeh Salehnia

    2009-01-01

    Full Text Available Background: An evaluation of the developmental competence of vitrified mouse germinal vesicle(GV oocytes with various equilibration and vitrification times; in the presence or absence ofcumulus cells and by comparison between the cryotop method and straws was performed.Materials and Methods: Mouse GV oocytes were considered in cumulus-denuded oocytes(CDOs and cumulus-oocyte complexes (COCs groups. Their survival and developmental rateswere studied in the following experiments: (I exposure to different equilibration times (0, 3 and5 minutes and vitrification (1, 3 and 5 minutes without plunging in LN2 as toxicity tests, (IIoocytes were vitrified using straws followed by exposure to equilibration solution for 0, 3 and 5minutes and vitrification solution for 1 and 3 minutes, and (III oocytes were vitrified by cryotopfollowing exposure to equilibration for 5 minutes and vitrification for 1 minute, respectively.Results: Maturation and developmental rates of the COCs were higher than CDOs in the nonvitrifiedgroup (p<0.05. The survival and maturation rates were low in all oocytes exposed tovitrification solution for 5 minutes (p <0.05. In vitrified CDOs and COCs using straws, the survivalrates ranged from 56.9% to 85.4% and 44.0% to 84.5%, and the maturation rates from 35.3% to56.8% and 25.8% to 56.2%, respectively; which were lower than non-vitrified samples (p <0.05.Cryotop vitrified oocytes showed higher survival, maturation and fertilization rates when comparedto straw in both CDOs and COCs (p <0.05.Conclusion: The presence of cumulus cells improves developmental competence of GV oocytesin control groups but it did not affect the vitrified group. Vitrification of mouse GV oocytes usingcryotop was more effective than straws, however both vitrification techniques did not improve thecleavage rate.

  8. ON THE ACTIVITY OF α-AMYLASE IN SOME CULTURE AND SPONTANEOUS GRAMINACEAE, DURING THEIR GERMINATION PERIOD

    Directory of Open Access Journals (Sweden)

    Elena Ciornea

    2006-08-01

    amylase (595.871 M maltose / g has been evidenced 12 hours after the beginning of germination, while, in the case of bristle grass, -amylase attains the maximum level of its activity after 144 hours of germination (429.824 M maltose / g.

  9. Comparison of Gene Expression Profiles in Human Germinal Vesicle Before and After Cytoplasmic Transfer From Mature Oocytes in Iranian Infertile Couples

    Directory of Open Access Journals (Sweden)

    Fatemeh Sadat Hoseini

    2016-08-01

    Full Text Available Objective: To evaluate the effect of cytoplasm transfer from mature oocytes to germinal vesicle(GVs on promoting the maturation of cytoplasm of GV at the mRNA level.Materials and methods: Sixty six in vitro fertilization (IVF operations between June 2012 and November 2013 were included in this study. Totally 120 GVs were obtained. Normal GVs were categorized into 3 groups (n = 40 randomly: the first comprised oocytes that did not receive the cytoplasm of mature oocytes; the second group comprised oocytes that did not receive the cytoplasm of mature oocytes but were incubated for 24 h; and the third group comprised oocytes that received 10-15% the cytoplasm of mature oocytes and were then incubated for 24 h. Each group was separately analyzed by quantitative polymerase chain reaction (qPCR and the expression levels of selected genes were assessed.Results: The expression levels of genes involved in the cytoplasmic maturity, and energy-producing mitochondria were significantly higher in the pooled oocytes of 2nd control group than those of the 1st control and intervention groups (p < 0.001. The genes involved in the meiosis, spindle check point, DNA repairing and cell cycle checkpoint did not have any expression in the 1st and intervention groups; however, these genes were expressed in the 2nd group, significantly. In the 2nd group, the highest expression level was observed for genes involved in the DNA repairing and cell cycle checkpoint. In the intervention group, none of the genes were expressed except for energy-producing mitochondria gene; even in this case, the expression level of this gene in this group of oocytes was significantly lower than that in other groups (p < 0.001. After 24 h meiosis assumption was significantly higher in the third group than in the second group (95% vs. 68%, p < 0.001.Conclusion: The cytoplasm transfer technique is not effective in cytoplasmic maturity of the recipient GV oocytes. In contrast, 24-hr in

  10. The fate and role of macromolecules synthesized during mammalian oocyte meiotic maturation. I. Autoradiographic topography of newly synthesized RNA and protein in the germinal vesicle of the pig and rabbit

    International Nuclear Information System (INIS)

    Motlik, J.; Kopecny, V.; Pivko, J.

    1978-01-01

    Pig and rabbit oocytes were cytoautoradiographically checked for their synthetic activities during meiotic maturation. Tritiated uridine and lysine or 35 S-methionine were introduced into the culture medium in which the oocytes were maintained either immediately at the beginning of the germinal vesicle breakdown in vitro or after reaching a more advanced stage of this process in vitro or in vivo. Some oocytes were maintained thereafter in a cold medium to trace the metabolism of the labelled protein. In addition to uridine- 3 H incorporation into the nucleolus and nucleoplasm, during pig oocyte maturation it was found that an intensive RNA synthesis site appeared in association with condensing chromocentres of the GV II. A considerable proportion of oocytes from slaughterhouse material did not show intensive GV activity in RNA synthesis during maturation in vitro. In the pig and rabbit oocyte it was shown that the newly synthesized 3 H-lysine-labelled protein accumulated to a high degree in the GV and in the nucleolus. The labelled protein accumulated in the GV up to the stage of GV IV (pig) and persisted during the chase period in the ooplasm; it was found to be associated with chromosomes of metaphase I (pig) or metaphase II (rabbit) of the meiotic division. The process of protein accumulation in the GV was not influenced by meiotic arrest during oocyte culture in autologous follicular fluid. A similar accumulation of the label in the GV was detected in oocytes which were cultured in a medium enriched by 35 S-methionine. In some oocytes the labelled protein failed to accumulate in the nucleolar area during maturation in vitro

  11. Vesicle electrohydrodynamics.

    Science.gov (United States)

    Schwalbe, Jonathan T; Vlahovska, Petia M; Miksis, Michael J

    2011-04-01

    A small amplitude perturbation analysis is developed to describe the effect of a uniform electric field on the dynamics of a lipid bilayer vesicle in a simple shear flow. All media are treated as leaky dielectrics and fluid motion is described by the Stokes equations. The instantaneous vesicle shape is obtained by balancing electric, hydrodynamic, bending, and tension stresses exerted on the membrane. We find that in the absence of ambient shear flow, it is possible that an applied stepwise uniform dc electric field could cause the vesicle shape to evolve from oblate to prolate over time if the encapsulated fluid is less conducting than the suspending fluid. For a vesicle in ambient shear flow, the electric field damps the tumbling motion, leading to a stable tank-treading state.

  12. Barley germination

    DEFF Research Database (Denmark)

    Daneri-Castro, Sergio N.; Svensson, Birte; Roberts, Thomas H.

    2016-01-01

    germination. Lastly, the application of metabolomics to barley grain germination provides essential data on biochemical processes, including insights into the formation of compounds that contribute to malt quality. To maximize the benefits of the 'omics' revolution to the malting industry, there is a need......Germination of barley grain is central to the malting industry and is a valuable model for cereal grain germination. Our current understanding of the complexity of germination at the molecular level is facilitated by access to genomic, transcriptomic, proteomic and metabolomic data. Here we review...... of germination in the context of industrial malting. For transcriptomics, recent advances in sequencing the barley genome allow next-generation sequencing approaches to reveal novel effects of variety and environment on germination. For proteomics, selection of the source tissue(s) and the protein extraction...

  13. Nuclear dynamics during ascospore germination in Sordaria macrospora.

    Science.gov (United States)

    Teichert, Ines

    2017-01-01

    The ascomycete Sordaria macrospora has a long history as a model organism for studying fungal sexual development. Starting from an ascospore, sexual fruiting bodies (perithecia) develop within seven days and discharge new ascospores. Sexual development has been studied in detail, revealing genes required for perithecium formation and ascospore germination. However, the germination process per se has not yet been examined. Here I analyze nuclear dynamics during ascospore germination using a fluorescently labeled histone. Live-cell imaging revealed that nuclei are transported into germination vesicles that form on one side of the spore. Polar growth is established from these vesicles. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Vesicles and vesicle gels - structure and dynamics of formation

    International Nuclear Information System (INIS)

    Gradzielski, M

    2003-01-01

    Vesicles constitute an interesting morphology formed by self-aggregating amphiphilic molecules. They exhibit a rich structural variety and are of interest both from a fundamental point of view (for studying closed bilayer systems) and from a practical point of view (whenever one is interested in the encapsulation of active molecules). In many circumstances vesicular structures have to be formed by external forces, but of great interest are amphiphilic systems, where they form spontaneously. Here the question arises of whether this means that they are also thermodynamically stable structures, which at least in some systems appears to be the case. If such vesicles are well defined in size, it is possible to pack them densely and thereby form vesicle gels that possess highly elastic properties even for relatively low volume fractions of amphiphile. Conditions for the formation and the microstructure of such vesicle gels have been studied in some detail for the case of unilamellar vesicles. Another important and topical issue is the dynamics of vesicle formation/breakdown, as the understanding of the transition process will open the way to a deeper understanding of their stability and also allow controlling of the structures formed, by means of their formation processes. Significant progress in the study of the transformation processes has been achieved, in particular by means of time-resolved scattering experiments. (topical review)

  15. Spin State As a Probe of Vesicle Self-Assembly.

    Science.gov (United States)

    Kim, Sanghoon; Bellouard, Christine; Eastoe, Julian; Canilho, Nadia; Rogers, Sarah E; Ihiawakrim, Dris; Ersen, Ovidiu; Pasc, Andreea

    2016-03-02

    A novel system of paramagnetic vesicles was designed using ion pairs of iron-containing surfactants. Unilamellar vesicles (diameter ≈ 200 nm) formed spontaneously and were characterized by cryogenic transmission electron microscopy, nanoparticle tracking analysis, and light and small-angle neutron scattering. Moreover, for the first time, it is shown that magnetization measurements can be used to investigate self-assembly of such functionalized systems, giving information on the vesicle compositions and distribution of surfactants between the bilayers and the aqueous bulk.

  16. Spin State As a Probe of Vesicle Self-Assembly

    OpenAIRE

    Kim, Sanghoon; Bellouard, Christine; Eastoe, Julian; Canilho, Nadia; Rogers, Sarah E; Ihiawakrim, Dris; Ersen, Ovidiu; Pasc, Andreea

    2016-01-01

    A novel system of paramagnetic vesicles was designed using ion pairs of iron-containing surfactants. Unilamellar vesicles (diameter ≈ 200 nm) formed spontaneously and were characterized by cryogenic transmission electron microscopy, nanoparticle tracking analysis, and light and small-angle neutron scattering. Moreover, for the first time, it is shown that magnetization measurements can be used to investigate self-assembly of such functionalized systems, giving information on the vesicle compo...

  17. Structure formation in binary mixtures of lipids and detergents: self-assembly and vesicle division.

    Science.gov (United States)

    Noguchi, Hiroshi

    2013-01-14

    Self-assembly dynamics in binary surfactant mixtures and structure changes of lipid vesicles induced by detergent solution are studied using coarse-grained molecular simulations. Disk-shaped micelles, the bicelles, are stabilized by detergents surrounding the rim of a bilayer disk of lipids. The self-assembled bicelles are considerably smaller than bicelles formed from vesicle rupture, and their size is determined by the concentrations of lipids and detergents and the interactions between the two species. The detergent-adsorption induces spontaneous curvature of the vesicle bilayer and results in vesicle division into two vesicles or vesicle rupture into worm-like micelles. The division occurs mainly via the inverse pathway of the modified stalk model. For large spontaneous curvature of the monolayers of the detergents, a pore is often opened, thereby leading to vesicle division or worm-like micelle formation.

  18. Dynamics of coarsening in multicomponent lipid vesicles with non-uniform mechanical properties

    Science.gov (United States)

    Funkhouser, Chloe M.; Solis, Francisco J.; Thornton, K.

    2014-04-01

    Multicomponent lipid vesicles are commonly used as a model system for the complex plasma membrane. One phenomenon that is studied using such model systems is phase separation. Vesicles composed of simple lipid mixtures can phase-separate into liquid-ordered and liquid-disordered phases, and since these phases can have different mechanical properties, this separation can lead to changes in the shape of the vesicle. In this work, we investigate the dynamics of phase separation in multicomponent lipid vesicles, using a model that couples composition to mechanical properties such as bending rigidity and spontaneous curvature. The model allows the vesicle surface to deform while conserving surface area and composition. For vesicles initialized as spheres, we study the effects of phase fraction and spontaneous curvature. We additionally initialize two systems with elongated, spheroidal shapes. Dynamic behavior is contrasted in systems where only one phase has a spontaneous curvature similar to the overall vesicle surface curvature and systems where the spontaneous curvatures of both phases are similar to the overall curvature. The bending energy contribution is typically found to slow the dynamics by stabilizing configurations with multiple domains. Such multiple-domain configurations are found more often in vesicles with spheroidal shapes than in nearly spherical vesicles.

  19. Fusion of Nonionic Vesicles

    DEFF Research Database (Denmark)

    Bulut, Sanja; Oskolkova, M. Z.; Schweins, R.

    2010-01-01

    We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures ar...... a barrier to fusion changing from 15 k(B)T at T = 26 degrees C to 10k(H) T at T = 35 degrees C. These results are compatible with the theoretical predictions using the stalk model of vesicle fusion....

  20. A Germination Simulation.

    Science.gov (United States)

    Hershey, David R.

    1995-01-01

    Presents an activity that involves using sponge seedlings to demonstrate the germination process without the usual waiting period. Discusses epigeous versus hypogeous germination, and cotyledon number and biodiversity. (JRH)

  1. Selective Metal-Ion-Mediated Vesicle Adhesion Based on Dynamic Self-Organization of a Pyrene-Appended Glutamic Acid.

    Science.gov (United States)

    Xing, Pengyao; Wang, Yajie; Yang, Minmin; Zhang, Yimeng; Wang, Bo; Hao, Aiyou

    2016-07-13

    Vesicles with dynamic membranes provide an ideal model system for investigating biological membrane activities, whereby vesicle aggregation behaviors including adhesion, fusion, fission, and membrane contraction/extension have attracted much attention. In this work we utilize an aromatic amino acid (pyrene-appended glutamic acid, PGlu) to prepare nanovesicles that aggregate to form vesicle clusters selectively induced by Fe(3+) or Cu(2+), and the vesicles transform into irregular nano-objects when interacting with Al(3+). Vesicle clusters have better stability than pristine vesicles, which hinders the spontaneous morphological transformation from vesicles into lamellar nanosheets with long incubation period. The difference between complexation of Fe(3+) and Al(3+) with vesicles was studied by various techniques. On the basis of metal ion-vesicle interactions, this self-assembled nanovesicle system also behaves as an effective fluorescent sensor for Fe(3+) and Al(3+), which cause fluorescence quenching and enhanced excimer emission, respectively.

  2. Molecular dynamics simulation of the formation, structure, and dynamics of small phospholipid vesicles

    NARCIS (Netherlands)

    Marrink, SJ; Mark, AE

    2003-01-01

    Here, we use coarse grained molecular dynamics (MD) simulations to study the spontaneous aggregation of dipalmitoylphosphatidylcholine (DPPC) lipids into small unilamellar vesicles. We show that the aggregation process occurs on a nanosecond time scale, with bicelles and cuplike vesicles formed at

  3. Seminal vesicle cycts

    International Nuclear Information System (INIS)

    Alpern, M.B.; Dorfman, R.E.; Gross, B.H.; Gottlieb, C.A.; Sandler, M.A.

    1990-01-01

    PURPOSE: Adult polycystic kidney disease (APKCD), an autosomal dominant disorder, causes cyst formation in the kidney, liver, pancreas, esophagus, ovaries, uterus, and brain. This paper describes four APKCD patients with CT evidence of seminal vesicle cysts (SVCs). Four patients (aged 45-65 years) underwent abdominal/pelvic CT with oral and intravenous contrast material. Three were evaluated for possible renal transplantation and one for sepsis material. All seminal vesicles contained cystic masses with fluid that measured between 0 and 30 HU. Seminal vesicle thickness was 3-4 cm (normal, 1.5 cm). High-density walls separated the 3-12-mm diameter cysts. All patients demonstrated typical renal stigmata of APKCD. One patient had hepatic cysts, and none had cysts elsewhere. Postmortem examination in one patient confirmed the SVCs

  4. Vesicle-based rechargeable batteries

    Energy Technology Data Exchange (ETDEWEB)

    Stanish, I.; Singh, A. [Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375 (United States); Lowy, D.A. [Nova Research, Inc., 1900 Elkin St., Alexandria, VA 22308 (United States); Hung, C.W. [Department of Chemical Engineering, University of Maryland, College Park, MD 20742 (United States)

    2005-05-02

    Vesicle-based rechargeable batteries can be fabricated by mounting polymerized vesicles filled with ferrocyanide or ferricyanide to a conductive surface. The potential can be adjusted by changing the concentration ratio of hydroquinone and benzoquinone bound to the vesicle membranes. These batteries show promise as a means of supplying portable power for future autonomous nanosystems. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  5. Growth and instability of a phospholipid vesicle in a bath of fatty acids

    Science.gov (United States)

    Dervaux, J.; Noireaux, V.; Libchaber, A. J.

    2017-06-01

    Using a microfluidic trap, we study the behavior of individual phospholipid vesicles in contact with fatty acids. We show that spontaneous fatty acids insertion inside the bilayer is controlled by the vesicle size, osmotic pressure difference across the membrane and fatty acids concentration in the external bath. Depending on these parameters, vesicles can grow spherically or become unstable and fragment into several daughter vesicles. We establish the phase diagram for vesicle growth and we derive a simple thermodynamic model that reproduces the time evolution of the vesicle volume. Finally, we show that stable growth can be achieved on an artificial cell expressing a simple set of bacterial cytoskeletal proteins, paving the way toward artificial cell reproduction.

  6. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    Science.gov (United States)

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  7. Lipids, lipid bilayers and vesicles as seen by neutrons

    International Nuclear Information System (INIS)

    Seto, Hideki

    2011-01-01

    Lipid molecules self-assemble into bilayers in water with their hydrocarbon chains facing inward due to their amphiphilic nature. The structural and dynamical properties of lipids and lipid bilayers have been studied by neutron scattering intensively. In this article, 3 topics are shown as typical examples. 1) a time-resolved small-angle neutron scattering on uni-lamellar vesicles composed of deuterated and protonated lipids to determine lipid kinetics, 2) small-angle neutron scattering to investigate spontaneous formation of nanopores on uni-lamellar vesicles, and 3) neutron spin echo study to determine bending modulus of lipid bilayers. (author)

  8. Seed dormancy and germination.

    Science.gov (United States)

    Penfield, Steven

    2017-09-11

    Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  9. Testicular germinal tumors

    International Nuclear Information System (INIS)

    Fresco, R.

    2010-01-01

    This work is about diagnosis, treatment and monitoring of testicular germinal tumors. The presumed diagnosis is based in the anamnesis, clinical examination, testicular ultrasound and tumor markers. The definitive diagnosis is obtained through the inguinal radical orchidectomy

  10. Plane partition vesicles

    International Nuclear Information System (INIS)

    Rensburg, E J Janse van; Ma, J

    2006-01-01

    We examine partitions and their natural three-dimensional generalizations, plane partitions, as models of vesicles undergoing an inflation-deflation transition. The phase diagrams of these models include a critical point corresponding to an inflation-deflation transition, and exhibits multicritical scaling in the vicinity of a multicritical point located elsewhere on the critical curve. We determine the locations of the multicritical points by analysing the generating functions using analytic and numerical means. In addition, we determine the numerical values of the multicritical scaling exponents associated with the multicritical scaling regimes in these models

  11. Dynamics of Shape Fluctuations of Quasi-spherical Vesicles Revisited

    DEFF Research Database (Denmark)

    Miao, L.; Lomholt, Michael Andersen; Kleis, J.

    2002-01-01

    In this paper, the dynamics of spontaneous shape fluctuations of a single, giant quasi-spherical vesicle formed from a single lipid species is revisited theoretically. A coherent physical theory for the dynamics is developed based on a number of fundamental principles and considerations, and a sy......In this paper, the dynamics of spontaneous shape fluctuations of a single, giant quasi-spherical vesicle formed from a single lipid species is revisited theoretically. A coherent physical theory for the dynamics is developed based on a number of fundamental principles and considerations...... of the phenomenological constants in a canonical continuum description of fluid lipid-bilayer membranes and shown the consequences of this new interpretation in terms of the characteristics of the dynamics of vesicle shape fluctuations. Moreover, we have used the systematic formulation of our theory as a framework...... against which we have discussed the previously existing theories and their discrepancies. Finally, we have made a systematic prediction about the system-dependent characteristics of the relaxation dynamics of shape fluctuations of quasi-spherical vesicles with a view of experimental studies...

  12. Vesicles and vesicle fusion: coarse-grained simulations

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2010-01-01

    of vesicles that is crucial for this transport is their ability to fuse to target membranes and release their contents to the distal side. In industry, some personal care products contain vesicles to help transport reagents across the skin, and research on drug formulation shows that packaging active......Biological cells are highly dynamic, and continually move material around their own volume and between their interior and exterior. Much of this transport encapsulates the material inside phospholipid vesicles that shuttle to and fro, fusing with, and budding from, other membranes. A feature...

  13. seed germination and seedlings growth

    African Journals Online (AJOL)

    STORAGESEVER

    2007-12-17

    Dec 17, 2007 ... The role of 20E in plant physiology including seed germination is not studied. ..... GA3, ABA and CKs on lettuce Lactuca sativa seed germination are ..... Practical uses for ecdysteroids in mammals and humans: an update. J.

  14. Tumors of germinal cells

    International Nuclear Information System (INIS)

    Plazas, Ricardo; Avila, Andres

    2002-01-01

    The tumors of germinal cells (TGC) are derived neoplasia of the primordial germinal cells that in the life embryonic migrant from the primitive central nervous system until being located in the gonads. Their cause is even unknown and they represent 95% of the testicular tumors. In them, the intention of the treatment is always healing and the diagnostic has improved thanks to the results of the handling multidisciplinary. The paper includes topics like their incidence and prevalence, epidemiology and pathology, clinic and diagnoses among other topics

  15. Knockin’ on pollen’s door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    Directory of Open Access Journals (Sweden)

    Frank eVogler

    2015-04-01

    Full Text Available Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane.

  16. Origins of microstructural transformations in charged vesicle suspensions: the crowding hypothesis.

    Science.gov (United States)

    Seth, Mansi; Ramachandran, Arun; Murch, Bruce P; Leal, L Gary

    2014-09-02

    It is observed that charged unilamellar vesicles in a suspension can spontaneously deflate and subsequently transition to form bilamellar vesicles, even in the absence of externally applied triggers such as salt or temperature gradients. We provide strong evidence that the driving force for this deflation-induced transition is the repulsive electrostatic pressure between charged vesicles in concentrated suspensions, above a critical effective volume fraction. We use volume fraction measurements and cryogenic transmission electron microscopy imaging to quantitatively follow both the macroscopic and microstructural time-evolution of cationic diC18:1 DEEDMAC vesicle suspensions at different surfactant and salt concentrations. A simple model is developed to estimate the extent of deflation of unilamellar vesicles caused by electrostatic interactions with neighboring vesicles. It is determined that when the effective volume fraction of the suspension exceeds a critical value, charged vesicles in a suspension can experience "crowding" due to overlap of their electrical double layers, which can result in deflation and subsequent microstructural transformations to reduce the effective volume fraction of the suspension. Ordinarily in polydisperse colloidal suspensions, particles interacting via a repulsive potential transform into a glassy state above a critical volume fraction. The behavior of charged vesicle suspensions reported in this paper thus represents a new mechanism for the relaxation of repulsive interactions in crowded situations.

  17. Biochemical Changes Associated with Germinating Rice Grains and Germination Improvement

    Directory of Open Access Journals (Sweden)

    Subajiny VELUPPILLAI

    2009-09-01

    Full Text Available To determine biochemical changes during the germination of rice grains (Oryza sativa L. subsp. indica var. Mottaikaruppan and to improve germination rate using gibberellic acid and surfactants [sodium dodecyl sulfate (SDS (1.0 g/L and Triton-X−100 (1.0 mL/L], whole rice grains soaked in distilled water for 12 h at 30°C were germinated in the dark at 30°C for five days. The highest germination rate (77.1% was obtained on the 5th day. An increase in the content of reducing sugars from 7.3 to 58.1 mg/g DM (dry matter was observed from the 1st day of germination. Free amino acids and soluble protein contents increased to 3.69 and 5.29 mg/g DM, respectively on the 5th day of germination. Total protein content decreased from 100.5 to 91.0 g/kg DM during germination. Increases in amylolytic (1.1 to 190.0 U/g DM and proteolytic (0 to 0.12 U/g DM activities were observed during germination. Effects of different concentrations of gibberellic acid on the germination of rice grains were evaluated and 0.1 g/L was found to promote germination. When effects of gibberellic acid (0.1 g/L and surfactants were evaluated individually and together, higher germination rate was observed in the control experiment (grains germinated in distilled water, whereas giberellic acid and surfactants decreased the germination rate. Therefore, the flour obtained from the grains germinated for four days using distilled water to obtain high content of soluble materials and enzyme activities can be used in preparation of bakery items.

  18. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  19. Extracellular vesicles: Exosomes, microvesicles, and friends

    NARCIS (Netherlands)

    Raposo, G.; Stoorvogel, W.|info:eu-repo/dai/nl/074352385

    2013-01-01

    Cells release into the extracellular environment diverse types of membrane vesicles of endosomal and plasma membrane origin called exosomes and microvesicles, respectively. These extracellular vesicles (EVs) represent an important mode of intercellular communication by serving as vehicles for

  20. Changes in germination characteristics and seedling growth ...

    African Journals Online (AJOL)

    Changes in germination characteristics and seedling growth between storage ... for up to 1 year and the second group was used for un-stored germination test. ... seed germination performance without loss of longevity of tall fescue species, ...

  1. Germination of Afrocarpus usambarensis and Podocarpus ...

    African Journals Online (AJOL)

    ACSS

    farm planting. Seed germination of .... 235. Germination of Afrocarpus usambarensis and Podocarpus milanjianus seeds. Table 2. Mean seed germination of A. usambarensis and P. milanjianus. Species .... National Forestry Authority and District.

  2. Structure formation of lipid membranes: Membrane self-assembly and vesicle opening-up to octopus-like micelles

    Science.gov (United States)

    Noguchi, Hiroshi

    2013-02-01

    We briefly review our recent studies on self-assembly and vesicle rupture of lipid membranes using coarse-grained molecular simulations. For single component membranes, lipid molecules self-assemble from random gas states to vesicles via disk-shaped clusters. Clusters aggregate into larger clusters, and subsequently the large disks close into vesicles. The size of vesicles are determined by kinetics than by thermodynamics. When a vesicle composed of lipid and detergent types of molecules is ruptured, a disk-shaped micelle called bicelle can be formed. When both surfactants have negligibly low critical micelle concentration, it is found that bicelles connected with worm-like micelles are also formed depending on the surfactant ratio and spontaneous curvature of the membrane monolayer.

  3. Impermeability effects in three-dimensional vesicles

    International Nuclear Information System (INIS)

    Biscari, P; Canevese, S M; Napoli, G

    2004-01-01

    We analyse the effects of the impermeability constraint on the equilibrium shapes of a three-dimensional vesicle hosting a rigid inclusion. A given alteration of the inclusion and/or vesicle parameters leads to shape modifications of different orders of magnitude, when applied to permeable or impermeable vesicles. Moreover, the enclosed-volume constraint wrecks the uniqueness of stationary equilibrium shapes, and gives rise to pear-shaped or stomatocyte-like vesicles

  4. Membrane Trafficking and Vesicle Fusion

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 5. Membrane Trafficking and Vesicle Fusion: Post-Palade Era Researchers Win the Nobel Prize. Riddhi Atul Jani Subba Rao Gangi Setty. General Article Volume 19 Issue 5 May 2014 pp 421-445 ...

  5. Ultrastructural examination of lead localisation in germinating seeds of Raphanus sativus

    Energy Technology Data Exchange (ETDEWEB)

    Lane, S.D.; Martin, E.S.

    1982-07-01

    Transmission electron microscopy of lead-contaminated germinating seeds has revealed that major sites of lead deposition exist within the cell wall and in association with spherosome-like vesicles common in all cells. There was also evidence of contamination of the plasmalemma, vacuole and subsequently the nucleus. In general radicle and hypocotyl tissue showed more extensive contamination than the cotyledons. The observations are discussed in relation to cell structure and development.

  6. Emergence and stability of intermediate open vesicles in disk-to-vesicle transitions.

    Science.gov (United States)

    Li, Jianfeng; Zhang, Hongdong; Qiu, Feng; Shi, An-Chang

    2013-07-01

    The transition between two basic structures, a disk and an enclosed vesicle, of a finite membrane is studied by examining the minimum energy path (MEP) connecting these two states. The MEP is constructed using the string method applied to continuum elastic membrane models. The results reveal that, besides the commonly observed disk and vesicle, open vesicles (bowl-shaped vesicles or vesicles with a pore) can become stable or metastable shapes. The emergence, stability, and probability distribution of these open vesicles are analyzed. It is demonstrated that open vesicles can be stabilized by higher-order elastic energies. The estimated probability distribution of the different structures is in good agreement with available experiments.

  7. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

  8. Germination of red alder seed.

    Science.gov (United States)

    M.A. Radwan; D.S. DeBell

    1981-01-01

    Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

  9. A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

    Directory of Open Access Journals (Sweden)

    M. Lauren Donnelly

    2017-01-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG, a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies.

  10. Formation of Oligovesicular Vesicles by Micromanipulation

    Directory of Open Access Journals (Sweden)

    Yukihisa Okumura

    2011-09-01

    Full Text Available Cell-sized lipid bilayer membrane vesicles (giant vesicles, GVs or semi-vesicles were formed from egg yolk phosphatidylcholine on a platinum electrode under applied electric voltage by electroformation. Micromanipulation of the semi-vesicle by first pressing its membrane with a glass microneedle and then withdrawing the needle left a GV in the interior of the vesicle. During the process, an aqueous solution of Ficoll that filled the needle was introduced into the newly formed inner vesicle and remained encapsulated. Approximately 50% of attempted micromanipulation resulted in the formation of an inner daughter vesicle, “microvesiculation”. By repeating the microvesiculation process, multiple inner GVs could be formed in a single parent semi-vesicle. A semi-vesicle with inner GVs could be detached from the electrode by scraping with a microneedle, yielding an oligovesicular vesicle (OVV with desired inner aqueous contents. Microvesiculation of a GV held on the tip of a glass micropipette was also possible, and this also produced an OVV. Breaking the membrane of the parent semi-vesicle by micromanipulation with a glass needle after microvesiculation, released the inner GVs. This protocol may be used for controlled formation of GVs with desired contents.

  11. Portable Diagnostics and Rapid Germination

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Zachary Spencer [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-12-01

    In the Bioenergy and Defense Department of Sandia National Laboratories, characterization of the BaDx (Bacillus anthracis diagnostic cartridge) was performed and rapid germination chemistry was investigated. BaDx was tested with complex sample matrixes inoculated with Bacillus anthracis, and the trials proved that BaDx will detect Bacillus anthracis in a variety of the medium, such as dirt, serum, blood, milk, and horse fluids. The dimensions of the device were altered to accommodate an E. coli or Listeria lateral flow immunoassay, and using a laser printer, BaDx devices were manufactured to identify E. coli and Listeria. Initial testing with E. coli versions of BaDx indicate that the device will be viable as a portable diagnostic cartridge. The device would be more effective with faster bacteria germination; hence studies were performed the use of rapid germination chemistry. Trials with calcium dipicolinic acid displayed increased cell germination, as shown by control studies using a microplate reader. Upon lyophilization the rapid germination chemistry failed to change growth patterns, indicating that the calcium dipicolinic acid was not solubilized under the conditions tested. Although incompatible with the portable diagnostic device, the experiments proved that the rapid germination chemistry was effective in increasing cell germination.

  12. Phospholipid Vesicles in Materials Science

    Energy Technology Data Exchange (ETDEWEB)

    Granick, Steve [Univ. of Illinois, Champaign, IL (United States)

    2016-05-11

    The objective of this research was to develop the science basis needed to deploy phospholipid vesicles as functional materials in energy contexts. Specifically, we sought to: (1) Develop an integrated molecular-level understanding of what determines their dynamical shape, spatial organization, and responsiveness to complex, time-varying environments; and (2) Develop understanding of their active transportation in crowded environments, which our preliminary measurements in cells suggest may hold design principles for targeting improved energy efficiency in new materials systems. The methods to do this largely involved fluorescence imaging and other spectroscopy involving single particles, vesicles, particles, DNA, and endosomes. An unexpected importance outcome was a new method to image light-emitting diodes during actual operation using super-resolution spectroscopy.

  13. 7 CFR 201.63 - Germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested. Mean...

  14. Germination of Aspergillus niger conidia

    OpenAIRE

    Hayer, Kimran

    2014-01-01

    Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

  15. Optogenetic acidification of synaptic vesicles and lysosomes.

    Science.gov (United States)

    Rost, Benjamin R; Schneider, Franziska; Grauel, M Katharina; Wozny, Christian; Bentz, Claudia; Blessing, Anja; Rosenmund, Tanja; Jentsch, Thomas J; Schmitz, Dietmar; Hegemann, Peter; Rosenmund, Christian

    2015-12-01

    Acidification is required for the function of many intracellular organelles, but methods to acutely manipulate their intraluminal pH have not been available. Here we present a targeting strategy to selectively express the light-driven proton pump Arch3 on synaptic vesicles. Our new tool, pHoenix, can functionally replace endogenous proton pumps, enabling optogenetic control of vesicular acidification and neurotransmitter accumulation. Under physiological conditions, glutamatergic vesicles are nearly full, as additional vesicle acidification with pHoenix only slightly increased the quantal size. By contrast, we found that incompletely filled vesicles exhibited a lower release probability than full vesicles, suggesting preferential exocytosis of vesicles with high transmitter content. Our subcellular targeting approach can be transferred to other organelles, as demonstrated for a pHoenix variant that allows light-activated acidification of lysosomes.

  16. Ultrasound-responsive ultrathin multiblock copolyamide vesicles

    Science.gov (United States)

    Huang, Lei; Yu, Chunyang; Huang, Tong; Xu, Shuting; Bai, Yongping; Zhou, Yongfeng

    2016-02-01

    This study reports the self-assembly of novel polymer vesicles from an amphiphilic multiblock copolyamide, and the vesicles show a special structure with an ultrathin wall thickness of about 4.5 nm and a combined bilayer and monolayer packing model. Most interestingly, the vesicles are ultrasound-responsive and can release the encapsulated model drugs in response to ultrasonic irradiation.This study reports the self-assembly of novel polymer vesicles from an amphiphilic multiblock copolyamide, and the vesicles show a special structure with an ultrathin wall thickness of about 4.5 nm and a combined bilayer and monolayer packing model. Most interestingly, the vesicles are ultrasound-responsive and can release the encapsulated model drugs in response to ultrasonic irradiation. Electronic supplementary information (ESI) available: Details of experiments and characterization, and FT-IR, TEM, DPD, FL and micro-DSC results. See DOI: 10.1039/c5nr08596a

  17. [Spontaneous hypoglycemia].

    Science.gov (United States)

    Ellorhaoui, M; Schultze, W

    1977-01-15

    On the basis of a survey is attempted to describe mode of development, symptomatology, individual forms and the different possibilities of therapy of the spontaneous hypoglycaemias. A particularly broad range was devoted to the cerebral sequelae, since in these cases--according to our experience--on account of simulation of neurologico-psychiatric symptoms at the soonest wrong diagnoses are to be expected. Furthermore, it is attempted to classify the hypoglycemias according to their development, in which cases their incompleteness was evident from the very beginning. The individual forms of appearance are treated according their to significance. Out of the inducible hypoglycaemias a particular attention is devoted to the forms caused by insulin and oral antidiabetics, since these most frequently participate in the development. Finally the author inquires into diagnostic measures for recognition of special forms of hypoglycaemia. In this place the diagnostics of hyperinsulinism conditioned by adenomatosis or tumours of other kinds is of particular importance. Finally conservative and operative possibilities of the therapy of these tumours are discussed,whereby the only recently tested treatment with streptotocin is mentioned.

  18. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles

    NARCIS (Netherlands)

    Farsi, Z.; Preobraschenski, J.; Bogaart, G. van den; Riedel, D.; Jahn, R.; Woehler, A.

    2016-01-01

    Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided

  19. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  20. Trafficking of astrocytic vesicles in hippocampal slices

    International Nuclear Information System (INIS)

    Potokar, Maja; Kreft, Marko; Lee, So-Young; Takano, Hajime; Haydon, Philip G.; Zorec, Robert

    2009-01-01

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  1. Extracellular Vesicles in Hematological Disorders

    Directory of Open Access Journals (Sweden)

    Anat Aharon

    2014-10-01

    Full Text Available Extracellular vesicles (EVs, comprised of exosomes, microparticles, apoptotic bodies, and other microvesicles, are shed from a variety of cells upon cell activation or apoptosis. EVs promote clot formation, mediate pro-inflammatory processes, transfer proteins and miRNA to cells, and induce cell signaling that regulates cell differentiation, proliferation, migration, invasion, and apoptosis. This paper will review the contribution of EVs in hematological disorders, including hemoglobinopathies (sickle cell disease, thalassemia, paroxysmal nocturnal hemoglobinuria, and hematological malignancies (lymphomas, myelomas, and acute and chronic leukemias.

  2. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    OpenAIRE

    L?sser, Cecilia; Th?ry, Clotilde; Buz?s, Edit I.; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; L?tvall, Jan

    2016-01-01

    The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field co...

  3. Time-resolved small-angle neutron scattering of a micelle-to-vesicle transition

    Energy Technology Data Exchange (ETDEWEB)

    Egelhaaf, S U [Institut Max von Laue - Paul Langevin (ILL), 38 -Grenoble (France); Schurtenberger, P [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-04-01

    Amphiphilic molecules spontaneously self-assemble in solution to form a variety of aggregates. Only limited information is available on the kinetics of the structural transitions as well as on the existence of non-equilibrium or metastable states. Aqueous mixtures of lecithin and bile salt are very interesting biological model-systems which exhibit a spontaneous transition from polymer-like mixed micelles to vesicles upon dilution. The small-angle neutron scattering (SANS) instrument D22, with its very high neutron flux and the broad range of scattering vectors covered in a single instrumental setting, allowed us for the first time to perform time-resolved scattering experiments in order to study the micelle-to-vesicle transition. The temporal evolution of the aggregate structures were followed and detailed information was obtained even on molecular length-scales. (author). 5 refs.

  4. Effects of Silodosin and Tamsulosin on the Seminal Vesicle Contractile Response.

    Science.gov (United States)

    Hayashi, Tokumasa; Takeya, Mitsue; Nakamura, Kei-ichiro; Matsuoka, Kei

    2016-01-01

    To understand the mechanisms underlying ejaculation dysfunction caused by α1A-adrenocetor (AR) antagonists, the effects of α1A-AR antagonists on the contractile responses of the seminal vesicle were investigated. Isolated seminal vesicles from guinea pigs were cannulated and pressurized, and the changes in the intraluminal pressure were recorded. Periodic applications of electrical stimulation (ES) caused biphasic increase in the intraluminal pressure, that is, initial and subsequent contractions. The effects of silodosin and tamsulosin, α1A-AR antagonists, on the contractile responses were examined. The ES-induced biphasic contractions were blocked by tetrodotoxin (TTX). Silodosin and tamsulosin suppressed the initial contractions in a dose-dependent manner, while also exerting various inhibitory effects on the subsequent contractions. Increases in the intraluminal pressure facilitated spontaneous phasic contractions. The spontaneous contractions were not affected by TTX or α1A-AR antagonists, but were abolished by nifedipine. The initial contractions triggered by neuronal excitations were suppressed by silodosin and tamsulosin, suggesting that the ejaculation dysfunction may be attributed to the α1A-AR antagonist-mediated suppression of nerve-evoked contractions in the seminal vesicle. The subsequent contractions may be induced by mechanical stimulation associated with the initial, nerve-evoked contractions. Alternatively, other transmitters may be involved to various degrees in the neuromuscular transmission of the seminal vesicle. © 2014 Wiley Publishing Asia Pty Ltd.

  5. Synaptic vesicle distribution by conveyor belt.

    Science.gov (United States)

    Moughamian, Armen J; Holzbaur, Erika L F

    2012-03-02

    The equal distribution of synaptic vesicles among synapses along the axon is critical for robust neurotransmission. Wong et al. show that the continuous circulation of synaptic vesicles throughout the axon driven by molecular motors ultimately yields this even distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Amyloglucosidase enzymatic reactivity inside lipid vesicles

    Directory of Open Access Journals (Sweden)

    Kim Jin-Woo

    2007-10-01

    Full Text Available Abstract Efficient functioning of enzymes inside liposomes would open new avenues for applications in biocatalysis and bioanalytical tools. In this study, the entrapment of amyloglucosidase (AMG (EC 3.2.1.3 from Aspergillus niger into dipalmitoylphosphatidylcholine (DPPC multilamellar vesicles (MLVs and large unilamellar vesicles (LUVs was investigated. Negative-stain, freeze-fracture, and cryo-transmission electron microscopy images verified vesicle formation in the presence of AMG. Vesicles with entrapped AMG were isolated from the solution by centrifugation, and vesicle lamellarity was identified using fluorescence laser confocal microscopy. The kinetics of starch hydrolysis by AMG was modeled for two different systems, free enzyme in aqueous solution and entrapped enzyme within vesicles in aqueous suspension. For the free enzyme system, intrinsic kinetics were described by a Michaelis-Menten kinetic model with product inhibition. The kinetic constants, Vmax and Km, were determined by initial velocity measurements, and Ki was obtained by fitting the model to experimental data of glucose concentration-time curves. Predicted concentration-time curves using these kinetic constants were in good agreement with experimental measurements. In the case of the vesicles, the time-dependence of product (glucose formation was experimentally determined and simulated by considering the kinetic behavior of the enzyme and the permeation of substrate into the vesicle. Experimental results demonstrated that entrapped enzymes were much more stable than free enyzme. The entrapped enzyme could be recycled with retention of 60% activity after 3 cycles. These methodologies can be useful in evaluating other liposomal catalysis operations.

  7. Quantal basis of vesicle growth and information content, a unified approach.

    Science.gov (United States)

    Nitzany, Eyal; Hammel, Ilan; Meilijson, Isaac

    2010-09-07

    Secretory vesicles express a periodic multimodal size distribution. The successive modes are integral multiples of the smallest mode (G(1)). The vesicle content ranges from macromolecules (proteins, mucopolysaccharides and hormones) to low molecular weight molecules (neurotransmitters). A steady-state model has been developed to emulate a mechanism for the introduction of vesicles of monomer size, which grow by a unit addition mechanism, G(1)+G(n)-->G(n+1) which, at a later stage are eliminated from the system. We describe a model of growth and elimination transition rates which adequately illustrates the distributions of vesicle population size at steady-state and upon elimination. Consequently, prediction of normal behavior and pathological perturbations is feasible. Careful analysis of spontaneous secretion, as compared to short burst-induced secretion, suggests that the basic character-code for reliable communication should be within a range of only 8-10 vesicles' burst which may serve as a yes/no message. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. High-Throughput Scoring of Seed Germination.

    Science.gov (United States)

    Ligterink, Wilco; Hilhorst, Henk W M

    2017-01-01

    High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very informative as it lacks information about start, rate, and uniformity of germination, which are highly indicative of such traits as dormancy, stress tolerance, and seed longevity. The calculation of cumulative germination curves requires information about germination percentage at various time points. We developed the GERMINATOR package: a simple, highly cost-efficient, and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The GERMINATOR package contains three modules: (I) design of experimental setup with various options to replicate and randomize samples; (II) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (III) curve fitting of cumulative germination data and the extraction, recap, and visualization of the various germination parameters. GERMINATOR is a freely available package that allows the monitoring and analysis of several thousands of germination tests, several times a day by a single person.

  9. Weak Static and Extremely Low Frequency Magnetic Fields Affect In Vitro Pollen Germination

    Directory of Open Access Journals (Sweden)

    Lucietta Betti

    2011-01-01

    Full Text Available This study concerns the effects of a weak static magnetic field (MF at 10 μT oriented downward, combined with a 16-Hz sinusoidal MF (10 μT, on in vitro pollen germination of kiwifruit (Actinidia deliciosa. Extremely low frequency magnetic field (ELF-MF exposure was carried out by a signal generator unit connected to a copper wire solenoid, inside which samples where placed. Two different kinds of treatment were performed: direct and indirect. In the direct treatment, pollen samples were directly exposed during rehydration, germination, or both. In the indirect treatment, the pollen growth medium was prepared with water aliquots (at standard temperature of 20°C and pH = 6.74 that were exposed before use for 8 or 24 h. The main purpose of our research was to identify a biological marker (in vitro pollen germination in a stressing growth medium without Ca2+ susceptible to the effects of direct or indirect ELF-MF exposure. The working variable was the pollen germination rate, as detected blind after 3 h 30 min by an Axioplan microscope. A directionally consistent recovery of germination percentage was observed both for direct exposure (during germination and both rehydration and germination phases and water-mediated exposure (with water exposed for 24 h and immediately used. Our results suggest that the ELF-MF treatment might partially remove the inhibitory effect caused by the lack of Ca2+ in the culture medium, inducing a release of internal Ca2+ stored in the secretory vesicles of pollen plasma membrane. Although preliminary, findings seem to indicate the in vitro pollen performance as adequate to study the effects of ELF-MFs on living matter.

  10. Ethylene, seed germination, and epinasty.

    Science.gov (United States)

    Stewart, E R; Freebairn, H T

    1969-07-01

    Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.

  11. Responsive Polydiacetylene Vesicles for Biosensing Microorganisms

    Directory of Open Access Journals (Sweden)

    Estelle Lebègue

    2018-02-01

    Full Text Available Polydiacetylene (PDA inserted in films or in vesicles has received increasing attention due to its property to undergo a blue-to-red colorimetric transition along with a change from non-fluorescent to fluorescent upon application of various stimuli. In this review paper, the principle for the detection of various microorganisms (bacteria, directly detected or detected through the emitted toxins or through their DNA, and viruses and of antibacterial and antiviral peptides based on these responsive PDA vesicles are detailed. The analytical performances obtained, when vesicles are in suspension or immobilized, are given and compared to those of the responsive vesicles mainly based on the vesicle encapsulation method. Many future challenges are then discussed.

  12. Spontaneous Pneumothorax

    Directory of Open Access Journals (Sweden)

    John Costumbrado

    2017-09-01

    Full Text Available History of present illness: A 16-year-old male with asthma was brought to the emergency department by his parents for increasing right-sided chest pain associated with cough and mild dyspnea over the past week. Albuterol inhaler did not provide relief. He denied recent trauma, fever, sweats, and chills. The patient’s vitals and oxygen saturations were stable. Physical exam revealed a tall, slender body habitus with no signs of chest wall injuries. Bilateral breath sounds were present, but slightly diminished on the right. A chest radiograph was ordered to determine the etiology of the patient’s symptoms. Significant findings: Initial chest radiograph showed a 50% right-sided pneumothorax with no mediastinal shift, which can be identified by the sharp line representing the pleural lung edge (see arrows and lack of peripheral lung markings extending to the chest wall. While difficult to accurately estimate volume from a two-dimensional image, a 2 cm pneumothorax seen on chest radiograph correlates to approximately 50% volume.1 The patient underwent insertion of a pigtail pleural drain on the right and repeat chest radiograph showed resolution of previously seen pneumothorax. Ultimately the pigtail drain was removed and chest radiograph showed clear lung fields without evidence of residual pneumothorax or pleural effusion. Discussion: Pneumothorax is characterized by air between the lungs and the chest wall.2 Spontaneous pneumothorax (SP occurs when the pneumothorax is not due to trauma or any discernable etiology. 3 SP is multifactorial and may be associated with subpleural blebs, bullae, and other connective tissue changes that predispose the lungs to leak air into the pleural space.4 SP can be further subdivided into primary (no history of underlying lung disease or secondary (history of chronic obstructive pulmonary disease, tuberculosis, cystic fibrosis, lung malignancy, etc..2 It is estimated that the incidence of SP among US pediatric

  13. Thermodynamics and kinetics of vesicles formation processes.

    Science.gov (United States)

    Guida, Vincenzo

    2010-12-15

    Vesicles are hollow aggregates, composed of bilayers of amphiphilic molecules, dispersed into and filled with a liquid solvent. These aggregates can be formed either as equilibrium or as out of equilibrium meta-stable structures and they exhibit a rich variety of different morphologies. The surprising richness of structures, the vast range of industrial applications and the presence of vesicles in a number of biological systems have attracted the interest of numerous researchers and scientists. In this article, we review both the thermodynamics and the kinetics aspects of the phenomena of formation of vesicles. We start presenting the thermodynamics of bilayer membranes formation and deformation, with the aim of deriving the conditions for the existence of equilibrium vesicles. Specifically, we use the results from continuum thermodynamics to discuss the possibility of formation of stable equilibrium vesicles, from both mixed amphiphiles and single component systems. We also link the bilayer membrane properties to the molecular structure of the starting amphiphiles. In the second part of this article, we focus on the dynamics and kinetics of vesiculation. We review the process of vesicles formation both from planar lamellar phase under shear and from isotropic micelles. In order to clarify the physical mechanisms of vesicles formation, we continuously draw a parallel between emulsification and vesiculation processes. Specifically, we compare the experimental results, the driving forces and the relative scaling laws identified for the two processes. Describing the dynamics of vesicles formation, we also discuss why non equilibrium vesicles can be formed by kinetics control and why they are meta-stable. Understanding how to control the properties, the stability and the formation process of vesicles is of fundamental importance for a vast number of industrial applications. Copyright © 2009. Published by Elsevier B.V.

  14. COMPARATIVE GERMINATION RESPONSES OF COWPEA AND ...

    African Journals Online (AJOL)

    iya beji

    inadequate soil moisture (25%) in both cowpea and maize with greater effect on ... Of all factors controlling productivity, seed germination and vigour are pre- .... depth and date of first irrigation on seed cane germination of two commercial.

  15. Describing phytotoxic effects on cumulative germination

    OpenAIRE

    Dias, L.S.

    2001-01-01

    Phytotoxic studies strongly depend on evaluation of germination responses, which implies the need for adequate procedures to account for distinct aspects of the germinative process. For this, indices, comparisons among treatments at various times, and model fitting have been proposed. The objective of this work is to compare the three approaches and select the one providing greater insight and precision. Speed of germination, speed of accumulated germination, the coefficient of the rate of ge...

  16. Methods for assessing Phytophthora ramorum chlamydospore germination

    Science.gov (United States)

    Joyce Eberhart; Elilzabeth Stamm; Jennifer Parke

    2013-01-01

    Germination of chlamydospores is difficult to accurately assess when chlamydospores are attached to remnants of supporting hyphae. We developed two approaches for closely observing and rigorously quantifying the frequency of chlamydospore germination in vitro. The plate marking and scanning method was useful for quantifying germination of large...

  17. 7 CFR 201.20 - Germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed present...

  18. Seed germination in parasitic plants: what insights can we expect from strigolactone research?

    Science.gov (United States)

    Brun, Guillaume; Braem, Lukas; Thoiron, Séverine; Gevaert, Kris; Goormachtig, Sofie; Delavault, Philippe

    2018-04-23

    Obligate root-parasitic plants belonging to the Orobanchaceae family are deadly pests for major crops all over the world. Because these heterotrophic plants severely damage their hosts even before emerging from the soil, there is an unequivocal need to design early and efficient methods for their control. The germination process of these species has probably undergone numerous selective pressure events in the course of evolution, in that the perception of host-derived molecules is a necessary condition for seeds to germinate. Although most of these molecules belong to the strigolactones, structurally different molecules have been identified. Since strigolactones are also classified as novel plant hormones that regulate several physiological processes other than germination, the use of autotrophic model plant species has allowed the identification of many actors involved in the strigolactone biosynthesis, perception, and signal transduction pathways. Nevertheless, many questions remain to be answered regarding the germination process of parasitic plants. For instance, how did parasitic plants evolve to germinate in response to a wide variety of molecules, while autotrophic plants do not? What particular features are associated with their lack of spontaneous germination? In this review, we attempt to illustrate to what extent conclusions from research into strigolactones could be applied to better understand the biology of parasitic plants.

  19. Vesicles Are Persistent Features of Different Plastids.

    Science.gov (United States)

    Lindquist, Emelie; Solymosi, Katalin; Aronsson, Henrik

    2016-10-01

    Peripheral vesicles in plastids have been observed repeatedly, primarily in proplastids and developing chloroplasts, in which they are suggested to function in thylakoid biogenesis. Previous observations of vesicles in mature chloroplasts have mainly concerned low temperature pretreated plants occasionally treated with inhibitors blocking vesicle fusion. Here, we show that such vesicle-like structures occur not only in chloroplasts and proplastids, but also in etioplasts, etio-chloroplasts, leucoplasts, chromoplasts and even transforming desiccoplasts without any specific pretreatment. Observations are made both in C3 and C4 species, in different cell types (meristematic, epidermis, mesophyll, bundle sheath and secretory cells) and different organs (roots, stems, leaves, floral parts and fruits). Until recently not much focus has been given to the idea that vesicle transport in chloroplasts could be mediated by proteins, but recent data suggest that the vesicle system of chloroplasts has similarities with the cytosolic coat protein complex II system. All current data taken together support the idea of an ongoing, active and protein-mediated vesicle transport not only in chloroplasts but also in other plastids, obviously occurring regardless of chemical modifications, temperature and plastid developmental stage. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. On the Computing Potential of Intracellular Vesicles.

    Science.gov (United States)

    Mayne, Richard; Adamatzky, Andrew

    2015-01-01

    Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca2+-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal 'circuitry' and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a 'vesicle modification' of the archetypal CBC 'billiard ball model' of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle 'programming' in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.

  1. MR imaging of the seminal vesicles

    International Nuclear Information System (INIS)

    Edson, S.B.; Hricak, H.; Chun-Fang Chang, Y.

    1987-01-01

    The seminal vesicles of 56 healthy males and 23 males with pathologic conditions were studied with a .35-T magnet and spin-echo (SE) techniques (repetition time/echo time [msec] = 500/30 and 2,000/60). The authors analyzed (1) the size and relative signal intensity of seminal vesicles compared to surrounding fat, muscle, or urine; (2) the effect of aging on the size and signal intensity of the vesicles, and (3) the appearance of the seminal vesicles in different pathologic conditions. In the transverse plane, the normal seminal vesicle measures 31 +- 7 mm in length and 17 +- 4 mm in width. Its size or signal intensity did not change significantly with age. On SE = 500/30 images the seminal vesicles were isointense with muscle; on SE = 2,000/60 images they were isointense or slightly hypointense relative to fat. MR imaging was highly sensitive for displaying seminal vesicle pathology, based on asymmetry in size and changes in signal intensities. MR imaging provides unique information but its role in pathologic conditions needs to be further explored

  2. Habitat specialization through germination cueing

    DEFF Research Database (Denmark)

    Ten Brink, Dirk-Jan; Hendriksma, Harmen; Bruun, Hans Henrik

    2013-01-01

    This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently...

  3. Cargo Release from Polymeric Vesicles under Shear

    Directory of Open Access Journals (Sweden)

    Yingying Guo

    2018-03-01

    Full Text Available In this paper we study the release of cargo from polymeric nano-carriers under shear. Vesicles formed by two star block polymers— A 12 B 6 C 2 ( A B C and A 12 B 6 A 2 ( A B A —and one linear block copolymer— A 14 B 6 ( A B , are investigated using dissipative particle dynamics (DPD simulations. A - and C -blocks are solvophobic and B -block is solvophilic. The three polymers form vesicles of different structures. The vesicles are subjected to shear both in bulk and between solvophobic walls. In bulk shear, the mechanisms of cargo release are similar for all vesicles, with cargo travelling through vesicle membrane with no preferential release location. When sheared between walls, high cargo release rate is only observed with A B C vesicle after it touches the wall. For A B C vesicle, the critical condition for high cargo release rate is the formation of wall-polymersome interface after which the effect of shear rate in promoting cargo release is secondary. High release rate is achieved by the formation of solvophilic pathway allowing cargo to travel from the vesicle cavity to the vesicle exterior. The results in this paper show that well controlled target cargo release using polymersomes can be achieved with polymers of suitable design and can potentially be very useful for engineering applications. As an example, polymersomes can be used as carriers for surface active friction reducing additives which are only released at rubbing surfaces where the additives are needed most.

  4. Germinal and somatic mutations in cancer

    International Nuclear Information System (INIS)

    Knudson, A.G. Jr.

    1977-01-01

    The role of germinal and somatic mutations in carcinogenesis leads to the conclusion that environmental carcinogens probably exert their effects via somatic mutations. Susceptibility to this process may itself be genetically determined, so we may deduce that two groups, one genetic and one non-genetic, are included in the 'environmental' class. Other individuals seem to acquire cancer even in the absence of such environmental agents, and these too may be classified into a genetic and a non-genetic group. It has been estimated that in industrial countries, the environmental groups include 70-80% of all cancer cases, but we are only beginning to know how to separate the genetic and non-genetic subgroups. The genetic subgroup of the 'non-environmental' group is very small, probably of the order of magnitude of 1-2% for cancer as a whole. The remainder, about 25%, comprises a non-genetic, non-environmental subgroup that seems to arise as a consequence of 'spontaneous' somatic mutations. The incidence of these 'background' cancers is what we should combat with preventive and therapeutic measures

  5. Synaptic model for spontaneous activity in developing networks

    DEFF Research Database (Denmark)

    Lerchner, Alexander; Rinzel, J.

    2005-01-01

    Spontaneous rhythmic activity occurs in many developing neural networks. The activity in these hyperexcitable networks is comprised of recurring "episodes" consisting of "cycles" of high activity that alternate with "silent phases" with little or no activity. We introduce a new model of synaptic...... dynamics that takes into account that only a fraction of the vesicles stored in a synaptic terminal is readily available for release. We show that our model can reproduce spontaneous rhythmic activity with the same general features as observed in experiments, including a positive correlation between...

  6. Influence of Insulin-like Growth Factor 1 on Nuclear Maturation of Germinal Vesicle Mouse Oocytes

    Directory of Open Access Journals (Sweden)

    R mahmoudi

    2014-09-01

    Full Text Available Background & aim: In vitro maturation and fertilization of oocytes play an important role in reproductive biotechnology. The aim of this study is to define the IGF-1 effect on in vitro maturation, fertilization and development of mice immature oocytes to 2-cells in TCM199 medium cultures. Methods: In this study 4 week old NMRI mice were used. Ovaries stimulation carried out using PMSG. GV oocytes with or without cumulus cells were isolated from ovaries and cultured in TCM199 in presence of 100 ng IGF-1 for 24hr.The oocytes (MII were inseminated with sperm in T6 medium for fertilization and development of 2-cells stage and they were investigated under inverted microscope. Data analysis was performed by using Chi- 2 test. Results: In cumulus cell group and in the presence of insulin-like growth factor fertilization of oocytes, forming embryos and the formation of 2-cells compared to the group without cumulus cells significantly increased (p < 0.05. Conclusion: As the results showed oocytes with cumulus cells in the presence of insulin-like growth factor enhances maturation, fertilization and embryonic development in 2-cells oocytes compared to group without cumulus cells TCM199.

  7. Oocyte transport: Developmental competence of bovine oocytes arrested at germinal vesicle stage by cycloheximide under air.

    Science.gov (United States)

    Hashimoto, Shu; Kimura, Kouji; Iwata, Hisataka; Takakura, Ryo

    2003-02-01

    The effects of the medium (TCM 199 or SOFaa) and temperature (20 or 39 C) during meiotic arrest by cycloheximide (CHX) under air on the developmental competence of bovine oocytes after in vitro maturation (IVM) and fertilization (IVF) were investigated. Oocytes were maintained in meiotic arrest by 10 microg/ml CHX in a 50-microl droplet of 25-mM HEPES-buffered TCM 199 (H199) at 39 C or synthetic oviduct fluid (HSOFaa) at 20 or 39 C in air for 24 h. After release from the arrest, the oocytes was matured and fertilized in vitro and their developmental competence was examined. The developmental rate of oocytes arrested in HSOFaa at 20 C to the blastocyst stage was similar to that of non-arrested oocytes but was significantly higher (Ptransport conditions, we also investigated the meiotic arrest of oocytes maintained in a 0.25-ml straw by CHX individually with 10 microl HSOFaa or as a group (40-50 oocytes) with 170-200 microl HSOFaa at 20 C in air for 24 h. After release from meiotic arrest, the developmental competence of these oocytes was assessed similarly. The developmental rate of oocytes treated with CHX individually was similar to that of those treated with CHX in 50-microl droplet of HSOFaa at 20 C. However, the developmental rate of oocytes treated with CHX as a group was lower than that of oocytes treated with CHX in a 50-microl droplet. Five blastocysts developed from oocytes maintained in meiotic arrest in a plastic straw were transferred to five recipient heifers. Consequently, three recipients became pregnant and 2 calves were delivered. The results of the present study indicate that bovine oocytes treated with CHX in HSOFaa at 20 C under air retain the same developmental competence as non-arrested oocytes.

  8. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  9. Synaptic Vesicle Endocytosis in Different Model Systems

    Directory of Open Access Journals (Sweden)

    Quan Gan

    2018-06-01

    Full Text Available Neurotransmission in complex animals depends on a choir of functionally distinct synapses releasing neurotransmitters in a highly coordinated manner. During synaptic signaling, vesicles fuse with the plasma membrane to release their contents. The rate of vesicle fusion is high and can exceed the rate at which synaptic vesicles can be re-supplied by distant sources. Thus, local compensatory endocytosis is needed to replenish the synaptic vesicle pools. Over the last four decades, various experimental methods and model systems have been used to study the cellular and molecular mechanisms underlying synaptic vesicle cycle. Clathrin-mediated endocytosis is thought to be the predominant mechanism for synaptic vesicle recycling. However, recent studies suggest significant contribution from other modes of endocytosis, including fast compensatory endocytosis, activity-dependent bulk endocytosis, ultrafast endocytosis, as well as kiss-and-run. Currently, it is not clear whether a universal model of vesicle recycling exist for all types of synapses. It is possible that each synapse type employs a particular mode of endocytosis. Alternatively, multiple modes of endocytosis operate at the same synapse, and the synapse toggles between different modes depending on its activity level. Here we compile review and research articles based on well-characterized model systems: frog neuromuscular junctions, C. elegans neuromuscular junctions, Drosophila neuromuscular junctions, lamprey reticulospinal giant axons, goldfish retinal ribbon synapses, the calyx of Held, and rodent hippocampal synapses. We will compare these systems in terms of their known modes and kinetics of synaptic vesicle endocytosis, as well as the underlying molecular machineries. We will also provide the future development of this field.

  10. Germination conditions affect physicochemical properties of germinated brown rice flour.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

    2009-01-01

    Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA.

  11. Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

    Directory of Open Access Journals (Sweden)

    Maik Hadorn

    Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

  12. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

    Science.gov (United States)

    Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

    2012-10-01

    A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

  13. Factors influencing seed germination in Cerrado grasses

    Directory of Open Access Journals (Sweden)

    Rosana Marta Kolb

    2016-03-01

    Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

  14. Effect of industrial pollution on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.Z.; Qadir, S.A.

    1973-01-01

    The germination behavior of seeds in polluted waters and polluted soil extracts was found to be identical, only a few species behaved differently. Prosopis juliflora, Haloxylon recurvum, Acacia senegal showed best germination in the two conditions but Prosopis juliflora was the most resistant to pollution. In Suaeda fruticosa no germination took place in the control treatment whereas highest germination (70%) was seen in treatment with polluted soil extract of EPLA. Blepharis sindica showed a stimulating effect of polluted water on germination, whereas low germination was observed when their seeds were treated with the soil extract of the same site. 40% germination of Suaeda monoica was seen in polluted water of Carbon and Ribbon Mfg. Co., whereas 30% germination was found in a control treatment. Low percentage of germination was found when the seeds of Cassia holosericea were treated with polluted waters of different industries as compared to soil extract treatments of the same industries. Datura alba showed 50, 30 and 10% seed germination in polluted soil extract of Carbon and Ribbon Mfg. Co., in control and in polluted water of Darbar Soap Works, respectively. 5 references, 1 table.

  15. Influence of membrane phospholipid composition and structural organization on spontaneous lipid transfer between membranes.

    Science.gov (United States)

    Pankov, R; Markovska, T; Antonov, P; Ivanova, L; Momchilova, A

    2006-09-01

    Investigations were carried out on the influence of phospholipid composition of model membranes on the processes of spontaneous lipid transfer between membranes. Acceptor vesicles were prepared from phospholipids extracted from plasma membranes of control and ras-transformed fibroblasts. Acceptor model membranes with manipulated levels of phosphatidylethanolamine (PE), sphingomyelin and phosphatidic acid were also used in the studies. Donor vesicles were prepared of phosphatidylcholine (PC) and contained two fluorescent lipid analogues, NBD-PC and N-Rh-PE, at a self-quenching concentration. Lipid transfer rate was assessed by measuring the increase of fluorescence in acceptor membranes due to transfer of fluorescent lipid analogues from quenched donor to unquenched acceptor vesicles. The results showed that spontaneous NBD-PC transfer increased upon fluidization of acceptor vesicles. In addition, elevation of PE concentration in model membranes was also accompanied by an increase of lipid transfer to all series of acceptor vesicles. The results are discussed with respect to the role of lipid composition and structural order of cellular plasma membranes in the processes of spontaneous lipid exchange between membrane bilayers.

  16. [The research of Valeriana amurensis seed germination characteristics].

    Science.gov (United States)

    Liu, Juan; Yang, Chun-Rong; Jiang, Bo; Fang, Min; Du, Juan

    2011-10-01

    To study the effect of different treatments on the Valeriana amurensis seed germination rate. Used different chemical reagents and seed soakings on the routine germination test and the orthogonal test of the Valeriana amurensis seed, calculated the germination rate under different germination condition. Valeriana amurensis treated with different chemical reagends had different germination rate. The suitable immersion time could enhance Valeriana amurensis seed germination rate. Different treatment time, different disposal temperature, different germination temperature would have an impact on the Valeriana amurensis seed germination rate. In order to raise the Valeriana amurensis seed germination rate, use appropriate treatment on the seed before plant seeds; The seed growing must under suitable time and temperature.

  17. 7 CFR 201.53 - Source of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from the... to size or appearance. (b) When only a germination test is required and the pure seed is estimated or...

  18. Are calcifying matrix vesicles in atherosclerotic lesions of cellular origin?

    Science.gov (United States)

    Bobryshev, Yuri V; Killingsworth, Murray C; Huynh, Thuan G; Lord, Reginald S A; Grabs, Anthony J; Valenzuela, Stella M

    2007-03-01

    Over recent years, the role of matrix vesicles in the initial stages of arterial calcification has been recognized. Matrix calcifying vesicles have been isolated from atherosclerotic arteries and the biochemical composition of calcified vesicles has been studied. No studies have yet been carried out to examine the fine structure of matrix vesicles in order to visualize the features of the consequent stages of their calcification in arteries. In the present work, a high resolution ultrastructural analysis has been employed and the study revealed that matrix vesicles in human atherosclerotic lesions are heterogeneous with two main types which we classified. Type I calcified vesicles were presented by vesicles surrounded by two electron-dense layers and these vesicles were found to be resistant to the calcification process in atherosclerotic lesions in situ. Type II matrix vesicles were presented by vesicles surrounded by several electron-dense layers and these vesicles were found to represent calcifying vesicles in atherosclerotic lesions. To test the hypothesis that calcification of matrix vesicles surrounded by multilayer sheets may occur simply as a physicochemical process, independently from the cell regulation, we produced multilamellar liposomes and induced their calcification in vitro in a manner similar to that occurring in matrix vesicles in atherosclerotic lesions in situ.

  19. Astrocytic Vesicle Mobility in Health and Disease

    Directory of Open Access Journals (Sweden)

    Robert Zorec

    2013-05-01

    Full Text Available Astrocytes are no longer considered subservient to neurons, and are, instead, now understood to play an active role in brain signaling. The intercellular communication of astrocytes with neurons and other non-neuronal cells involves the exchange of molecules by exocytotic and endocytotic processes through the trafficking of intracellular vesicles. Recent studies of single vesicle mobility in astrocytes have prompted new views of how astrocytes contribute to information processing in nervous tissue. Here, we review the trafficking of several types of membrane-bound vesicles that are specifically involved in the processes of (i intercellular communication by gliotransmitters (glutamate, adenosine 5'-triphosphate, atrial natriuretic peptide, (ii plasma membrane exchange of transporters and receptors (EAAT2, MHC-II, and (iii the involvement of vesicle mobility carrying aquaporins (AQP4 in water homeostasis. The properties of vesicle traffic in astrocytes are discussed in respect to networking with neighboring cells in physiologic and pathologic conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, and states in which astrocytes contribute to neuroinflammatory conditions.

  20. EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

    Directory of Open Access Journals (Sweden)

    A. V. Oberemko

    2014-12-01

    Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

  1. Zinnia Germination and Lunar Soil Amendment

    Science.gov (United States)

    Reese, Laura

    2017-01-01

    Germination testing was performed to determine the best method for germinating zinnias. This method will be used to attempt to germinate the zinnia seeds produced in space. It was found that seed shape may be critically important in determining whether a seed will germinate or not. The ability of compost and worm castings to remediate lunar regolith simulant for plant growth was tested. It was found that neither treatment effectively improves plant growth in lunar regolith simulant. A potential method of improving lunar regolith simulant by mixing it with arcillite was discovered.

  2. DOES JASMONIC ACID PREVENT THE GERMINATION

    OpenAIRE

    ÇAVUŞOĞLU, Kürşat

    2009-01-01

    Abstract: Effect of jasmonic acid on seed germination and seedling growth of barley (Hordeum vulgare L. cv. Bülbül 89) was investigated in the present study. Jasmonic acid concentrations less than 1500 µM have not inhibited the seed germination, while 1500 and 2000 µM jasmonic acid levels caused atypical germination. The germination was completely inhibited at 3000 µM level of jasmonic acid. However, the seedling growth clearly slowed down with increasing concentrations of jasmonic acid. Furt...

  3. GERMINATION STUDIES ON Tabebuia impetiginosa Mart. SEEDS

    Directory of Open Access Journals (Sweden)

    Edvaldo Aparecido Amaral da Silva

    2004-06-01

    Full Text Available Seed germination and seedling production of native forest tree species are an important step in ex situ conservation programs and in the reforestation with ecological purposes. Therefore, understanding seed germination and its regulation is mandatory for the complete success of the conservation programs and revegetation techniques. Thus, morphological studies, temperature requirements for seed germination and its control by gibberellins (GAs were studied in Tabebuia impetiginosa (“ipê-roxo” seeds. The best temperature for germination under constant light was 30oC. The imbibition of T. impetiginosa seeds followed the common triphasic pattern, with most of the seeds attaining phase II at 24 hours and phase III at 72 hours of imbibition. Visible germination, as radicle elongation, started at 30 hours in water-imbibed seeds and at 24 hours in GA-imbibed seeds. Seeds imbibed in Paclobutrazol, an inhibitor of GA biosynthesis, failed to germinate. However, application of exogenous gibberellins overcame inhibition and allowed germination, suggesting that GAs are regulators of Tabebuia impetiginosa seed germination. The results suggested that germination in Tabebuia impetiginosa seeds is controlled by elongation of the radicle and gibberellins may play an important role in regulating it. The possible role of gibberellins is discussed.

  4. Etude des potentialites germinatives pour une regeneration ...

    African Journals Online (AJOL)

    ... taux de germination a été obtenu avec des graines de petites tailles à la température ambiante (32°C). Le traitement préalable à l'eau de javel à 8% accroît le taux de germination (40% de réponse). La lumière et l'obscurité n'ont aucun effet sur la germination. Mots clés : Neocarya macrophylla, germination, régénération.

  5. Characteristics of minerals in vesicles produced by human osteoblasts hFOB 1.19 and osteosarcoma Saos-2 cells stimulated for mineralization.

    Science.gov (United States)

    Strzelecka-Kiliszek, Agnieszka; Bozycki, Lukasz; Mebarek, Saida; Buchet, Rene; Pikula, Slawomir

    2017-06-01

    Bone cells control initial steps of mineralization by producing extracellular matrix (ECM) proteins and releasing vesicles that trigger apatite nucleation. Using transmission electron microscopy with energy dispersive X-ray microanalysis (TEM-EDX) we compared the quality of minerals in vesicles produced by two distinct human cell lines: fetal osteoblastic hFOB 1.19 and osteosarcoma Saos-2. Both cell lines, subjected to osteogenic medium with ascorbic acid (AA) and β-glycerophosphate (β-GP), undergo the entire osteoblastic differentiation program from proliferation to mineralization, produce the ECM and spontaneously release vesicles. We observed that Saos-2 cells mineralized better than hFOB 1.19, as probed by Alizarin Red-S (AR-S) staining, tissue nonspecific alkaline phosphatase (TNAP) activity and by analyzing the composition of minerals in vesicles. Vesicles released from Saos-2 cells contained and were surrounded by more minerals than vesicles released from hFOB 1.19. In addition, there were more F and Cl substituted apatites in vesicles from hFOB 1.19 than in those from Saos-2 cells as determined by ion ratios. Saos-2 and h-FOB 1.19 cells revealed distinct mineralization profiles, indicating that the process of mineralization may proceed differently in various types of cells. Our findings suggest that TNAP activity is correlated with the relative proportions of mineral-filled vesicles and mineral-surrounded vesicles. The origin of vesicles and their properties predetermine the onset of mineralization at the cellular level. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A scenario for a genetically controlled fission of artificial vesicles

    DEFF Research Database (Denmark)

    Bönzli, Eva; Hadorn, Maik; Jørgensen, Mikkel Girke

    2011-01-01

    to vesicles (Hanczyc et al. 2003). In the present work, we developed a scenario how a genetically controlled fission of vesicles may be achieved by the synthesis of a special class of viral proteins within artificial vesicles. Because the authors already have a lot of experience in the water-in-oil emulsion...... be incorporated into vesicles, and therefore allow the synthesis of a large number of proteins (Noireaux et al. 2005). However, vesicle fission remains one of the upcoming challenges in the artificial cell project (Noireaux et al. 2011). So far, vesicle fission is implemented by applying mechanical stress...

  7. Inhibition of protein kinase C affects on mode of synaptic vesicle exocytosis due to cholesterol depletion

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Alexey M., E-mail: fysio@rambler.ru; Zakyrjanova, Guzalija F., E-mail: guzik121192@mail.ru; Yakovleva, Anastasia A., E-mail: nastya1234qwer@mail.ru; Zefirov, Andrei L., E-mail: zefiroval@rambler.ru

    2015-01-02

    Highlights: • We examine the involvement of PKC in MCD induced synaptic vesicle exocytosis. • PKC inhibitor does not decrease the effect MCD on MEPP frequency. • PKC inhibitor prevents MCD induced FM1-43 unloading. • PKC activation may switch MCD induced exocytosis from kiss-and-run to a full mode. • Inhibition of phospholipase C does not lead to similar change in exocytosis. - Abstract: Previous studies demonstrated that depletion of membrane cholesterol by 10 mM methyl-beta-cyclodextrin (MCD) results in increased spontaneous exocytosis at both peripheral and central synapses. Here, we investigated the role of protein kinase C in the enhancement of spontaneous exocytosis at frog motor nerve terminals after cholesterol depletion using electrophysiological and optical methods. Inhibition of the protein kinase C by myristoylated peptide and chelerythrine chloride prevented MCD-induced increases in FM1-43 unloading, whereas the frequency of spontaneous postsynaptic events remained enhanced. The increase in FM1-43 unloading still could be observed if sulforhodamine 101 (the water soluble FM1-43 quencher that can pass through the fusion pore) was added to the extracellular solution. This suggests a possibility that exocytosis of synaptic vesicles under these conditions could occur through the kiss-and-run mechanism with the formation of a transient fusion pore. Inhibition of phospholipase C did not lead to similar change in MCD-induced exocytosis.

  8. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  9. The biomechanics of seed germination.

    Science.gov (United States)

    Steinbrecher, Tina; Leubner-Metzger, Gerhard

    2017-02-01

    From a biomechanical perspective, the completion of seed (and fruit) germination depends on the balance of two opposing forces: the growth potential of the embryonic axis (radicle-hypocotyl growth zone) and the restraint of the seed-covering layers (endosperm, testa, and pericarp). The diverse seed tissues are composite materials which differ in their dynamic properties based on their distinct cell wall composition and water uptake capacities. The biomechanics of embryo cell growth during seed germination depend on irreversible cell wall loosening followed by water uptake due to the decreasing turgor, and this leads to embryo elongation and eventually radicle emergence. Endosperm weakening as a prerequisite for radicle emergence is a widespread phenomenon among angiosperms. Research into the biochemistry and biomechanics of endosperm weakening has demonstrated that the reduction in puncture force of a seed's micropylar endosperm is environmentally and hormonally regulated and involves tissue-specific expression of cell wall remodelling proteins such as expansins, diverse hydrolases, and the production of directly acting apoplastic reactive oxygen. The endosperm-weakening biomechanics and its underlying cell wall biochemistry differ between the micropylar (ME) and chalazal (CE) endosperm domains. In the ME, they involve cell wall loosening, cell separation, and programmed cell death to provide decreased and localized ME tissue resistance, autolysis, and finally the formation of an ME hole required for radicle emergence. Future work will further unravel the molecular mechanisms, environmental regulation, and evolution of the diverse biomechanical cell wall changes underpinning the control of germination by endosperm weakening. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  10. Comparative analysis of regulatory elements in different germin-like ...

    African Journals Online (AJOL)

    STORAGESEVER

    INTRODUCTION. Germin and germin-like proteins (GLPs) is a member of ..... analysis of germin-like protein gene 2 promoter from Oryza sativa L. ssp. Indica. ... esculenta Crantz) root proteome: Protein identification and differential expression.

  11. on seed germination and growth of Garcinia kola

    African Journals Online (AJOL)

    SARAH

    2016-07-31

    Jul 31, 2016 ... Seed germination tests: After 72 h of fermentation in plastic bags, seeds were ... Models (GLM) procedure of the R statistical version 9.1 was used to identify traits .... L-1) had accelerated seed germination. Germination rates.

  12. Irradiation-induced fusion between giant vesicles and photoresponsive large unilamellar vesicles containing malachite green derivative.

    Science.gov (United States)

    Uda, Ryoko M; Yoshikawa, Yuki; Kitaba, Moe; Nishimoto, Noriko

    2018-07-01

    Light-initiated fusion between vesicles has attracted much attention in the research community. In particular, fusion between photoresponsive and non-photoresponsive vesicles has been of much interest in the development of systems for the delivery of therapeutic agents to cells. We have performed fusion between giant vesicles (GVs) and photoresponsive smaller vesicles containing malachite green (MG) derivative, which undergoes ionization to afford a positive charge on the molecule by irradiation. The fusion proceeds as the concentration of GV lipid increases toward equimolarity with the lipid of the smaller vesicle. It is also dependent on the molar percentage of photoionized MG in the lipid of the smaller vesicle. On the other hand, the fusion is hardly affected by the anionic component of the GV. The photoinduced fusion was characterized by two methods, involving the mixing of lipid membranes and of aqueous contents. Fluorescence microscopy revealed that irradiation triggered the fusion of a single GV with the smaller vesicles containing MG. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Interference of the Histone Deacetylase Inhibits Pollen Germination and Pollen Tube Growth in Picea wilsonii Mast.

    Directory of Open Access Journals (Sweden)

    Yaning Cui

    Full Text Available Histone deacetylase (HDAC is a crucial component in the regulation of gene expression in various cellular processes in animal and plant cells. HDAC has been reported to play a role in embryogenesis. However, the effect of HDAC on androgamete development remains unclear, especially in gymnosperms. In this study, we used the HDAC inhibitors trichostatin A (TSA and sodium butyrate (NaB to examine the role of HDAC in Picea wilsonii pollen germination and pollen tube elongation. Measurements of the tip-focused Ca2+ gradient revealed that TSA and NaB influenced this gradient. Immunofluorescence showed that actin filaments were disrupted into disorganized fragments. As a result, the vesicle trafficking was disturbed, as determined by FM4-64 labeling. Moreover, the distribution of pectins and callose in cell walls was significantly altered in response to TSA and NaB. Our results suggest that HDAC affects pollen germination and polarized pollen tube growth in Picea wilsonii by affecting the intracellular Ca2+ concentration gradient, actin organization patterns, vesicle trafficking, as well as the deposition and configuration of cell wall components.

  14. Spontaneous external gallbladder perforation

    International Nuclear Information System (INIS)

    Noeldge, G.; Wimmer, B.; Kirchner, R.

    1981-01-01

    Spontaneous perforation of the gallbladder is one complication of cholelithiasis. There is a greater occurence of free perforation in the peritoneal cavity with bilary pertonitis, followed by the perforation into the stomach, small intestine and colon. A single case of the nowadays rare spontaneous perforation in and through the abdominal wall will be reported. Spontaneous gallbladder perforation appears nearly asymptomatic in its clinical course because of absent biliary peritonitis. (orig.) [de

  15. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  16. High Pressure Germination of Bacillus subtilis Spores with Alterations in Levels and Types of Germination Proteins

    Science.gov (United States)

    2014-01-01

    1ITLE AND SUBTITLE 5a CONTRACTNUMBER High pressure germination of Bacillus subtilis spores with W911NF-09-l-0286 alterations in levels and types of...A moderate high pressure (mHP) of 150 megaPascals (MPa) triggers germination of Bacillus subtilis spores via germinant receptors (GRs), while...germination by a very high pressure (vHP) of550 MPa is GR-independent. The mHP and vHP germination of Bacillus subtilis spores with different levels ofGRs

  17. ATM and ATR play complementary roles in the behavior of excitatory and inhibitory vesicle populations.

    Science.gov (United States)

    Cheng, Aifang; Zhao, Teng; Tse, Kai-Hei; Chow, Hei-Man; Cui, Yong; Jiang, Liwen; Du, Shengwang; Loy, Michael M T; Herrup, Karl

    2018-01-09

    ATM (ataxia-telangiectasia mutated) and ATR (ATM and Rad3-related) are large PI3 kinases whose human mutations result in complex syndromes that include a compromised DNA damage response (DDR) and prominent nervous system phenotypes. Both proteins are nuclear-localized in keeping with their DDR functions, yet both are also found in cytoplasm, including on neuronal synaptic vesicles. In ATM- or ATR-deficient neurons, spontaneous vesicle release is reduced, but a drop in ATM or ATR level also slows FM4-64 dye uptake. In keeping with this, both proteins bind to AP-2 complex components as well as to clathrin, suggesting roles in endocytosis and vesicle recycling. The two proteins play complementary roles in the DDR; ATM is engaged in the repair of double-strand breaks, while ATR deals mainly with single-strand damage. Unexpectedly, this complementarity extends to these proteins' synaptic function as well. Superresolution microscopy and coimmunoprecipitation reveal that ATM associates exclusively with excitatory (VGLUT1 + ) vesicles, while ATR associates only with inhibitory (VGAT + ) vesicles. The levels of ATM and ATR respond to each other; when ATM is deficient, ATR levels rise, and vice versa. Finally, blocking NMDA, but not GABA, receptors causes ATM levels to rise while ATR levels respond to GABA, but not NMDA, receptor blockade. Taken together, our data suggest that ATM and ATR are part of the cellular "infrastructure" that maintains the excitatory/inhibitory balance of the nervous system. This idea has important implications for the human diseases resulting from their genetic deficiency.

  18. Co-release of glutamate and GABA from single vesicles in GABAergic neurons exogenously expressing VGLUT3

    Directory of Open Access Journals (Sweden)

    Johannes eZimmermann

    2015-09-01

    Full Text Available The identity of the vesicle neurotransmitter transporter expressed by a neuron largely corresponds with the primary neurotransmitter that cell releases. However, the vesicular glutamate transporter subtype 3 (VGLUT3 is mainly expressed in non-glutamatergic neurons, including cholinergic, serotonergic, or GABAergic neurons. Though a functional role for glutamate release from these non-glutamatergic neurons has been demonstrated, the interplay between VGLUT3 and the neuron’s characteristic neurotransmitter transporter, particularly in the case of GABAergic neurons, at the synaptic and vesicular level is less clear. In this study, we explore how exogenous expression of VGLUT3 in striatal GABAergic neurons affects the packaging and release of glutamate and GABA in synaptic vesicles. We found that VGLUT3 expression in isolated, autaptic GABAergic neurons leads to action potential evoked release of glutamate. Under these conditions, glutamate and GABA could be packaged together in single vesicles release either spontaneously or asynchronously. However, the presence of glutamate in GABAergic vesicles did not affect uptake of GABA itself, suggesting a lack of synergy in vesicle filling for these transmitters. Finally, we found postsynaptic detection of glutamate released from GABAergic terminals difficult when bona fide glutamatergic synapses were present, suggesting that co-released glutamate cannot induce postsynaptic glutamate receptor clustering.

  19. Inhibition of barley grain germination by light

    NARCIS (Netherlands)

    Roth-Bejerano, N.; Meulen, R.M. van der; Wang, M.

    1996-01-01

    Intact grains of barley (Hordeum distichum cv. Triumph) germinated rapidly in the dark or when exposed to brief daily light breaks in the temperature range 15-25°C, although germination proceeded less rapidly at low temperatures. Prolonged illumination (16 h/day) or continuous light inhibited

  20. Germination and seedlings performance of cashew ( Anacardium ...

    African Journals Online (AJOL)

    The effects of nut-sowing orientations on the germination of cashew nuts and the responses of the resultant seedlings to cotyledon removed were studied in the nursery. While cashew nuts sown flat and those with stylar-end up had highest mean germination of 91.67 % and 92.50 % respectively the nuts sown with ...

  1. Seed germination behavior of swallow wort

    Directory of Open Access Journals (Sweden)

    amir hosein pahlavani

    2009-06-01

    Full Text Available The exotic plant, Swallow- wort, a twining perennial of the Milkweed family, has become increasingly invasive in some place of Iran, especially orchards. Increased knowledge of wort germination biology would facilitate development of an optimum control program. Germination of Swallow wort seeds as affected by environmental factors was studied under controlled-environment growth chamber conditions. The following studies were conducted in plant Pests & Diseases Research Institute during the years 2003-4: 1- Effect of constant temperature on germination that including 10, 15, 18, 20, 25, 30, 35 and 40˚C; 2- Effect of light on constant germination; 3- Effect of temperature fluctuations on seed germination: 15/7, 20/12, 25/17 and 30/22˚C. All experiments were conducted with 8 replications. Swallow wort seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore Swallow wort seeds were not photoblastic and temperature fluctuations did not increase seed germination of Swallow wort. The above characteristics are very important in making swallowwort an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.

  2. Oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, Oleg A.; Hasenstein, K. H.

    2003-05-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 μl O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

  3. Oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

    2003-01-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

  4. Comparative Germination Responses of Cowpea and Maize ...

    African Journals Online (AJOL)

    Germination, emergence and establishment phase are critical to the growth cycle of plant as it determines the density of the stand obtained. However, a number of factors including soil available moisture decrease seed germination and the rate of decline is found to vary with crop species. Pot experiment was therefore ...

  5. 7 CFR 201.6 - Germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered for transportation in whole or in part. The record shall show the kind of seed, lot number, date of test, percentage...

  6. Is seed conditioning essential for Orobanche germination?

    Science.gov (United States)

    Plakhine, Dina; Ziadna, Hammam; Joel, Daniel M

    2009-05-01

    Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity. Non-conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non-conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non-conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation. Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite-specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non-specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants.

  7. High-throughput scoring of seed germination

    NARCIS (Netherlands)

    Ligterink, Wilco; Hilhorst, Henk W.M.

    2017-01-01

    High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very

  8. Proteomics of Rice Seed Germination

    Directory of Open Access Journals (Sweden)

    Dongli eHe

    2013-07-01

    Full Text Available Seed is a condensed form of plant. Under suitable environmental conditions, it can resume the metabolic activity from physiological quiescent status, and mobilize the reserves, biosynthesize new proteins, regenerate organelles and cell membrane, eventually protrude the radicle and enter into seedling establishment. So far, how these activities are regulated in a coordinated and sequential manner is largely unknown. With the availability of more and more genome sequence information and the development of mass spectrometry (MS technology, proteomics has been widely applied in analyzing the mechanisms of different biological processes, and proved to be very powerful. Regulation of rice seed germination is critical for rice cultivation. In recent years, a lot of proteomic studies have been conducted in exploring the gene expression regulation, reserves mobilization and metabolisms reactivation, which brings us new insights on the mechanisms of metabolism regulation during this process. Nevertheless, it also invokes a lot of questions. In this mini-review, we summarized the progress in the proteomic studies of rice seed germination. The current challenges and future perspectives were also discussed, which might be helpful for the following studies.

  9. Functional transferred DNA within extracellular vesicles

    International Nuclear Information System (INIS)

    Cai, Jin; Wu, Gengze; Jose, Pedro A.; Zeng, Chunyu

    2016-01-01

    Extracellular vesicles (EVs) are small membrane vesicles including exosomes and shedding vesicles that mediated a cell-to-cell communication. EVs are released from almost all cell types under both physiological and pathological conditions and incorporate nuclear and cytoplasmic molecules for intercellular delivery. Besides protein, mRNA, and microRNA of these molecules, as recent studies show, specific DNA are prominently packaged into EVs. It appears likely that some of exosomes or shedding vesicles, bearing nuclear molecules are released upon bubble-like blebs. Specific interaction of EVs with susceptible recipients performs the uptake of EVs into the target cells, discharging their cargo including nuclear and cytoplasmic macromolecules into the cytosol. These findings expand the nucleic acid content of EVs to include increased levels of specific DNA. Thus, EVs contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer and atherosclerosis. In this review, the focus is on the characteristics, biological functions, and roles in diseases of DNA within EVs. - Highlights: • This review is focused on the DNA within EVs including its characteristics, biological functions, and roles in diseases. • It is clear that DNA within EVs might have important physiological and pathological roles in various diseases. • Knowledge in this area may provides us alternative methods for disease diagnosis or therapy in the future.

  10. Extracellular vesicles: fundamentals and clinical relevance

    Directory of Open Access Journals (Sweden)

    Wael Nassar

    2015-01-01

    Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

  11. Functional transferred DNA within extracellular vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Jin [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province (China); Wu, Gengze [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Jose, Pedro A. [Division of Nephrology, Department of Medicine and Physiology, University of Maryland, School of Medicine, Baltimore, MD 21201 (United States); Zeng, Chunyu, E-mail: Chunyuzeng01@163.com [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China)

    2016-11-15

    Extracellular vesicles (EVs) are small membrane vesicles including exosomes and shedding vesicles that mediated a cell-to-cell communication. EVs are released from almost all cell types under both physiological and pathological conditions and incorporate nuclear and cytoplasmic molecules for intercellular delivery. Besides protein, mRNA, and microRNA of these molecules, as recent studies show, specific DNA are prominently packaged into EVs. It appears likely that some of exosomes or shedding vesicles, bearing nuclear molecules are released upon bubble-like blebs. Specific interaction of EVs with susceptible recipients performs the uptake of EVs into the target cells, discharging their cargo including nuclear and cytoplasmic macromolecules into the cytosol. These findings expand the nucleic acid content of EVs to include increased levels of specific DNA. Thus, EVs contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer and atherosclerosis. In this review, the focus is on the characteristics, biological functions, and roles in diseases of DNA within EVs. - Highlights: • This review is focused on the DNA within EVs including its characteristics, biological functions, and roles in diseases. • It is clear that DNA within EVs might have important physiological and pathological roles in various diseases. • Knowledge in this area may provides us alternative methods for disease diagnosis or therapy in the future.

  12. Vesicle dynamics in shear and capillary flows

    International Nuclear Information System (INIS)

    Noguchi, Hiroshi; Gompper, Gerhard

    2005-01-01

    The deformation of vesicles in flow is studied by a mesoscopic simulation technique, which combines multi-particle collision dynamics for the solvent with a dynamically triangulated surface model for the membrane. Shape transitions are investigated both in simple shear flows and in cylindrical capillary flows. We focus on reduced volumes, where the discocyte shape of fluid vesicles is stable, and the prolate shape is metastable. In simple shear flow at low membrane viscosity, the shear induces a transformation from discocyte to prolate with increasing shear rate, while at high membrane viscosity, the shear induces a transformation from prolate to discocyte, or tumbling motion accompanied by oscillations between these two morphologies. In capillary flow, at small flow velocities the symmetry axis of the discocyte is found not to be oriented perpendicular to the cylinder axis. With increasing flow velocity, a transition to a prolate shape occurs for fluid vesicles, while vesicles with shear-elastic membranes (like red blood cells) transform into a coaxial parachute-like shape

  13. Theory of Disk-to-Vesicle Transformation

    Science.gov (United States)

    Li, Jianfeng; Shi, An-Chang

    2009-03-01

    Self-assembled membranes from amphiphilic molecules, such as lipids and block copolymers, can assume a variety of morphologies dictated by energy minimization of system. The membrane energy is characterized by a bending modulus (κ), a Gaussian modulus (κG), and the line tension (γ) of the edge. Two basic morphologies of membranes are flat disks that minimize the bending energy at the cost of the edge energy, and enclosed vesicles that minimize the edge energy at the cost of bending energy. In our work, the transition from disk to vesicle is studied theoretically using the string method, which is designed to find the minimum energy path (MEP) or the most probable transition path between two local minima of an energy landscape. Previous studies of disk-to-vesicle transition usually approximate the transitional states by a series of spherical cups, and found that the spherical cups do not correspond to stable or meta-stable states of the system. Our calculation demonstrates that the intermediate shapes along the MEP are very different from spherical cups. Furthermore, some of these transitional states can be meta-stable. The disk-to-vesicle transition pathways are governed by two scaled parameters, κG/κ and γR0/4κ, where R0 is the radius of the disk. In particular, a meta-stable intermediate state is predicted, which may correspond to the open morphologies observed in experiments and simulations.

  14. Compartmentalization and Transport in Synthetic Vesicles

    Directory of Open Access Journals (Sweden)

    Christine eSchmitt

    2016-02-01

    Full Text Available Nano-scale vesicles have become a popular tool in life sciences. Besides liposomes that are generated from phospholipids of natural origin, polymersomes fabricated of synthetic block copolymers enjoy increasing popularity, as they represent more versatile membrane building blocks that can be selected based on their specific physicochemical properties, like permeability, stability or chemical reactivity.In this review, we focus on the application of simple and nested artificial vesicles in synthetic biology. First, we provide an introduction into the utilization of multi-compartmented vesosomes as compartmentalized nano-scale bioreactors. In the bottom-up development of protocells from vesicular nano-reactors, the specific exchange of pathway intermediates across compartment boundaries represents a bottleneck for future studies. To date, most compartmented bioreactors rely on unspecific exchange of substrates and products. This is either based on changes in permeability of the coblock polymer shell by physicochemical triggers or by the incorporation of unspecific porin proteins into the vesicle membrane. Since the incorporation of membrane transport proteins into simple and nested artificial vesicles offers the potential for specific exchange of substances between subcompartments, it opens new vistas in the design of protocells. Therefore we devote the main part of the review to summarize the technical advances in the use of phospholipids and block copolymers for the reconstitution of membrane proteins.

  15. The Bretherton Problem for a Vesicle

    Science.gov (United States)

    Barakat, Joseph; Spann, Andrew; Shaqfeh, Eric

    2016-11-01

    The motion of a lipid bilayer vesicle through a circular tube is investigated by singular perturbation theory in the limit of vanishing clearance. The vesicle is treated as a sac of fluid enclosed by a thin, elastic sheet that admits a bending stiffness. It is assumed that the vesicle is axisymmetric and swollen to a near-critical volume such that the clearance "e" between the membrane and the tube wall is very small. In this limit, bending resistance is of negligible importance compared to the isotropic tension, allowing the vesicle to be treated as a "no-slip bubble." The effective membrane tension is found to scale inversely with "e" raised to the 3/2 power with a comparatively weak Marangoni gradient. The extra pressure drop is found to have a leading contribution due to the cylindrical midsection, which scales inversely with "e," as well as a correction due to the end caps, which scales inversely with the square root of "e." The apparent viscosity is predicted as a unique function of the geometry. The theory exhibits excellent agreement with a simplified, "quasi-parallel" theory and with direct numerical simulations using the boundary element method. The results of this work are compared to those for bubbles, rigid particles, and red blood cells in confined flows.

  16. Nanoplasmonic ruler to measure lipid vesicle deformation

    Czech Academy of Sciences Publication Activity Database

    Jackman, J.A.; Špačková, Barbora; Linardy, E.; Kim, M.C.; Yoon, B.K.; Homola, Jiří; Cho, N.J.

    2016-01-01

    Roč. 52, č. 1 (2016), s. 76-79 ISSN 1359-7345 R&D Projects: GA ČR(CZ) GBP205/12/G118 Institutional support: RVO:67985882 Keywords : nanomaterial * silicon * lipid vesicle Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 6.319, year: 2016

  17. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  18. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles.

    Science.gov (United States)

    Farsi, Zohreh; Preobraschenski, Julia; van den Bogaart, Geert; Riedel, Dietmar; Jahn, Reinhard; Woehler, Andrew

    2016-02-26

    Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and γ-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters. Copyright © 2016, American Association for the Advancement of Science.

  19. Influence of diesel fuel on seed germination

    International Nuclear Information System (INIS)

    Adam, Gillian; Duncan, Harry

    2002-01-01

    The volatile fraction of diesel fuel played a major role in delaying seed emergence and reducing percentage germination. - The use of plant-based systems to remediate contaminated soils has become an area of intense scientific study in recent years and it is apparent that plants which grow well in contaminated soils need to be identified and screened for use in phytoremediation technologies. This study investigated the effect of diesel fuel on germination of selected plant species. Germination response varied greatly with plant species and was species specific, as members of the same plant family showed differential sensitivity to diesel fuel contamination. Differences were also seen within plant subspecies. At relatively low levels of diesel fuel contamination, delayed seed emergence and reduced percentage germination was observed for the majority of plant species investigated. Results suggest the volatile fraction of diesel fuel played an influential role in delaying seed emergence and reducing percentage germination. In addition, the remaining diesel fuel in the soil added to this inhibitory effect on germination by physically impeding water and oxygen transfer between the seed and the surrounding soil environment, thus hindering the germination response

  20. [Study on germination characteristics of Disporum cantoniense].

    Science.gov (United States)

    Huang, Nan; Wang, Hua-Lei; Zhao, Zhi; Liu, Hong-Chang; Luo, Chun-Li; Li, Jin-Ling; Luo, Fu-Lai; Huang, Ming-Jin

    2012-11-01

    To study the seed germination characteristic and optimal germination condition of wild Disporum cantoniense. Used wild Disporum cantoniense seed as the test materials, the rate of water absorption of the seed was determined. The germination rates under different conditions, along a temperature gradient (15, 20, 25 and 30 degres C), in light or dark, on top or between wet filter papers, and keeping or removing the seed coat, were determined respectively using petri dish method. At the same time germination trends were observed. The thousand seed weight was 33.24 g, and the seed water-absorbing reached saturation pot after soaking for 30 h. Higher germination rates were respectively recorded at 25 degrees C, between filter papers, and in dark after 24 h soaking in the pretreatment solution. The optimal condition for the germination of the seed of wild Disporum cantoniense is as follow: keeping testa, seed soaking for 24 h in seed germination agent and being incubated between wet filter papers in dark at 25 degrees C.

  1. Germination of beans and snap beans seed

    Directory of Open Access Journals (Sweden)

    Zdravković Milan

    2000-01-01

    Full Text Available The aim of this study was to investigate germination of good bean seed of the variety Galeb and the bad bean seed of the same variety. We were also interested in germination of bean and snap bean seed damaged by grain weevil, and in germination of the seed treated by freezing which was aimed at controlling grain weevil by cold. We also recorded the differences between bean and snap bean seed, which was or was not treated by freezing in laboratory conditions. This investigation was carried out by applying the two factorial block system. The obtained results were evaluated by the variance analysis and x2 test These results suggest that the bean seed of a bad fraction had low levels of germination, but still it was present. Although the seed of good appearance was carefully selected, germination was slightly lower than it should have been. The seed with the large amount of grain weevils performed a high level germination in laboratory conditions. There were no differences in germination between the seed injured by grain weevil either in beans or in snap beans. As for the seed treated or untreated by freezing, there also were no differences between beans and snap beans. .

  2. Germination and elongation of flax in microgravity

    Science.gov (United States)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-05-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax ( Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 μL) outperforming the 400 μL, and 320 μL volumes for percent germination (90.6%) and root growth (mean = 4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean = 2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions.

  3. The oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, O.; Hasenstein, K.

    Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).

  4. Germination and elongation of flax in microgravity

    Science.gov (United States)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-01-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax (Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 microliters) outperforming the 400 microliters and 320 microliters volumes for percent germination (90.6%) and root growth (mean=4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean=2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  5. Genetically Controlled Fusion, Exocytosis and Fission of Artificial Vesicles

    DEFF Research Database (Denmark)

    Bönzli, Eva; Hadorn, Maik; De Lucrezia, Davide

    if a special class of viral proteins, termed fusogenic peptides, were added to the external medium. In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we enclosed synthesized peptides in vesicles...... to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different mechanisms are available, e.g. addition...... fusion, fission and exocytosis....

  6. Vesicle Origami and the Influence of Cholesterol on Lipid Packing.

    Science.gov (United States)

    Tanasescu, Radu; Lanz, Martin A; Mueller, Dennis; Tassler, Stephanie; Ishikawa, Takashi; Reiter, Renate; Brezesinski, Gerald; Zumbuehl, Andreas

    2016-05-17

    The artificial phospholipid Pad-PC-Pad was analyzed in 2D (monolayers at the air/water interface) and 3D (aqueous lipid dispersions) systems. In the gel phase, the two leaflets of a Pad-PC-Pad bilayer interdigitate completely, and the hydrophobic bilayer region has a thickness comparable to the length of a single phospholipid acyl chain. This leads to a stiff membrane with no spontaneous curvature. Forced into a vesicular structure, Pad-PC-Pad has faceted geometry, and in its extreme form, tetrahedral vesicles were found as predicted a decade ago. Above the main transition temperature, a noninterdigitated Lα phase with fluid chains has been observed. The addition of cholesterol leads to a slight decrease of the main transition temperature and a gradual decrease in the transition enthalpy until the transition vanishes at 40 mol % cholesterol in the mixture. Additionally, cholesterol pulls the chains apart, and a noninterdigitated gel phase is observed. In monolayers, cholesterol has an ordering effect on liquid-expanded phases and disorders condensed phases. The wavenumbers of the methylene stretching vibration indicate the formation of a liquid-ordered phase in mixtures with 40 mol % cholesterol.

  7. Stimulation of lettuce seed germination by ethylene.

    Science.gov (United States)

    Abeles, F B; Lonski, J

    1969-02-01

    Ethylene increased the germination of freshly imbibed lettuce (Lactuca sativa L. var. Grand Rapids) seeds. Seeds receiving either red or far-red light or darkness all showed a positive response to the gas. However, ethylene was apparently without effect on dormant seeds, those which failed to germinate after an initial red or far-red treatment. Carbon dioxide, which often acts as a competitive inhibitor of ethylene, failed to clearly reverse ethylene-enhanced seed germination. While light doubled ethylene production from the lettuce seeds, its effect was not mediated by the phytochrome system since both red and far-red light had a similar effect.

  8. 7 CFR 201.54 - Number of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of those... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54...

  9. Phytotoxicity of glyphosate in the germination of Pisum sativum and its effect on germinated seedlings

    OpenAIRE

    Mondal, Subinoy; Kumar, Mousumi; Haque, Smaranya; Kundu, Debajyoti

    2017-01-01

    The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds a...

  10. GERMINATOR: a software package for high-throughput scoring and curve fitting of Arabidopsis seed germination.

    Science.gov (United States)

    Joosen, Ronny V L; Kodde, Jan; Willems, Leo A J; Ligterink, Wilco; van der Plas, Linus H W; Hilhorst, Henk W M

    2010-04-01

    Over the past few decades seed physiology research has contributed to many important scientific discoveries and has provided valuable tools for the production of high quality seeds. An important instrument for this type of research is the accurate quantification of germination; however gathering cumulative germination data is a very laborious task that is often prohibitive to the execution of large experiments. In this paper we present the germinator package: a simple, highly cost-efficient and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The germinator package contains three modules: (i) design of experimental setup with various options to replicate and randomize samples; (ii) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (iii) curve fitting of cumulative germination data and the extraction, recap and visualization of the various germination parameters. The curve-fitting module enables analysis of general cumulative germination data and can be used for all plant species. We show that the automatic scoring system works for Arabidopsis thaliana and Brassica spp. seeds, but is likely to be applicable to other species, as well. In this paper we show the accuracy, reproducibility and flexibility of the germinator package. We have successfully applied it to evaluate natural variation for salt tolerance in a large population of recombinant inbred lines and were able to identify several quantitative trait loci for salt tolerance. Germinator is a low-cost package that allows the monitoring of several thousands of germination tests, several times a day by a single person.

  11. SNX9 - a prelude to vesicle release.

    Science.gov (United States)

    Lundmark, Richard; Carlsson, Sven R

    2009-01-01

    The sorting nexin SNX9 has, in the past few years, been singled out as an important protein that participates in fundamental cellular activities. SNX9 binds strongly to dynamin and is partly responsible for the recruitment of this GTPase to sites of endocytosis. SNX9 also has a high capacity for modulation of the membrane and might therefore participate in the formation of the narrow neck of endocytic vesicles before scission occurs. Once assembled on the membrane, SNX9 stimulates the GTPase activity of dynamin to facilitate the scission reaction. It has also become clear that SNX9 has the ability to activate the actin regulator N-WASP in a membrane-dependent manner to coordinate actin polymerization with vesicle release. In this Commentary, we summarize several aspects of SNX9 structure and function in the context of membrane remodeling, discuss its interplay with various interaction partners and present a model of how SNX9 might work in endocytosis.

  12. Stem cell extracellular vesicles and kidney injury

    OpenAIRE

    Grange, Cristina; Iampietro, Corinne; Bussolati, Benedetta

    2017-01-01

    Extracellular vesicles (EVs) appear as a new promising cell-free therapy for acute and chronic renal diseases. EVs retain characteristics of the cell of origin and those derived from stem cells may mimic their regenerative properties per se. In fact, EVs contain many active molecules such as proteins and RNA species that act on target cells through different mechanisms, stimulating proliferation and angiogenesis and reducing apoptosis and inflammation. There are several reports that demonstra...

  13. Endothelial microparticles: Sophisticated vesicles modulating vascular function

    Science.gov (United States)

    Curtis, Anne M; Edelberg, Jay; Jonas, Rebecca; Rogers, Wade T; Moore, Jonni S; Syed, Wajihuddin; Mohler, Emile R

    2015-01-01

    Endothelial microparticles (EMPs) belong to a family of extracellular vesicles that are dynamic, mobile, biological effectors capable of mediating vascular physiology and function. The release of EMPs can impart autocrine and paracrine effects on target cells through surface interaction, cellular fusion, and, possibly, the delivery of intra-vesicular cargo. A greater understanding of the formation, composition, and function of EMPs will broaden our understanding of endothelial communication and may expose new pathways amenable for therapeutic manipulation. PMID:23892447

  14. High energy irradiation of bacterial membrane vesicles

    International Nuclear Information System (INIS)

    De La Rosa, M.A.M.

    1977-01-01

    The interactions of membrane components and two well-defined transport systems in the E. coli ML 308-225 membrane vesicles with 60 Co gamma radiation were investigated. The results presented show that gamma radiation can monitor membrane components and functions of varying radiosensitivities. The possible application of high-energy radiation as a physical probe of membrane structure and functions is indeed promising

  15. Factors Affecting the Germination of Akinetes of Nodularia spumigena (Cyanobacteriaceae)

    OpenAIRE

    Huber, Ann L.

    1985-01-01

    Nutritional and physical factors which influence the germination of akinetes of Nodularia spumigena (Cyanobacteriaceae) were examined. Low concentrations of phosphorus (45 μM, inhibited germination. Salinities of >20‰ were inhibitory to germination. Optimum temperatures were 22°C or greater. Germination did not take place in the dark, but only very low light intensities (0.5 microeinstein m−2 s−1) were necessary to initiate germination. Red light (620 to 665 nm) was required. More than 24 h o...

  16. Imbibition and germination in the seeds of Heliotropium supinum L.

    Directory of Open Access Journals (Sweden)

    Ramesh C. Bhatia

    2014-01-01

    Full Text Available Imbibition in the seeds of Heliotropium supinum L. varies under different temperatures. The optimum temperatures for imbibition and germination are also different. For germination 39% imbibition is essential, and this capability is achieved by 12-week-old seeds. With duration of dry storage imbibition increases. The imbibition and germination percentages decline on re-dry storage of seeds after embeding in mud. A soil moisture of 44% is optimal for germination. A correlation exists between imbibition and germination.

  17. Investigation of coriander germination (Coriandrum sativum L.

    Directory of Open Access Journals (Sweden)

    Aćimović Milica

    2013-01-01

    Full Text Available Coriander seed yield (Coriandrum sativum L. depends of many factors during vegetation period, and also depend of seed quality. Coriander fruit (Coriandri fructus which is used like spice and in medicinal purpose, and also in food and pharmacy, in the same time is and seed material. Because of that, it is very important to take care about its quality. In this paper is analyzed seed material obtained from field experiments village Mošorin, in 2011, and investigated was conducted in harvest year, and one year later. In harvest year, germination energy in average was 38,21%, and total germination 72,75%. After one year, germination energy was statistically significant smaller - 16,50%, as like total germination which was 67,42%.

  18. Formation of protocell-like vesicles in a thermal diffusion column.

    Science.gov (United States)

    Budin, Itay; Bruckner, Raphael J; Szostak, Jack W

    2009-07-22

    Many of the properties of bilayer membranes composed of simple single-chain amphiphiles seem to be well-suited for a potential role as primitive cell membranes. However, the spontaneous formation of membranes from such amphiphiles is a concentration-dependent process in which a significant critical aggregate concentration (cac) must be reached. Since most scenarios for the prebiotic synthesis of fatty acids and related amphiphiles would result in dilute solutions well below the cac, the identification of mechanisms that would lead to increased local amphiphile concentrations is an important aspect of defining reasonable conditions for the origin of cellular life. Narrow, vertically oriented channels within the mineral precipitates of hydrothermal vent towers have previously been proposed to act as natural Clusius-Dickel thermal diffusion columns, in which a strong transverse thermal gradient concentrates dilute molecules through the coupling of thermophoresis and convection. Here we experimentally demonstrate that a microcapillary acting as a thermal diffusion column can concentrate a solution of oleic acid. Upon concentration, self-assembly of large vesicles occurs in regions where the cac is exceeded. We detected vesicle formation by fluorescence microscopy of encapsulated dye cargoes, which simultaneously concentrated in our channels. Our findings suggest a novel means by which simple physical processes could have led to the spontaneous formation of cell-like structures from a dilute prebiotic reservoir.

  19. Viscoelastic deformation of lipid bilayer vesicles.

    Science.gov (United States)

    Wu, Shao-Hua; Sankhagowit, Shalene; Biswas, Roshni; Wu, Shuyang; Povinelli, Michelle L; Malmstadt, Noah

    2015-10-07

    Lipid bilayers form the boundaries of the cell and its organelles. Many physiological processes, such as cell movement and division, involve bending and folding of the bilayer at high curvatures. Currently, bending of the bilayer is treated as an elastic deformation, such that its stress-strain response is independent of the rate at which bending strain is applied. We present here the first direct measurement of viscoelastic response in a lipid bilayer vesicle. We used a dual-beam optical trap (DBOT) to stretch 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) giant unilamellar vesicles (GUVs). Upon application of a step optical force, the vesicle membrane deforms in two regimes: a fast, instantaneous area increase, followed by a much slower stretching to an eventual plateau deformation. From measurements of dozens of GUVs, the average time constant of the slower stretching response was 0.225 ± 0.033 s (standard deviation, SD). Increasing the fluid viscosity did not affect the observed time constant. We performed a set of experiments to rule out heating by laser absorption as a cause of the transient behavior. Thus, we demonstrate here that the bending deformation of lipid bilayer membranes should be treated as viscoelastic.

  20. Routes and mechanisms of extracellular vesicle uptake

    Directory of Open Access Journals (Sweden)

    Laura Ann Mulcahy

    2014-08-01

    Full Text Available Extracellular vesicles (EVs are small vesicles released by donor cells that can be taken up by recipient cells. Despite their discovery decades ago, it has only recently become apparent that EVs play an important role in cell-to-cell communication. EVs can carry a range of nucleic acids and proteins which can have a significant impact on the phenotype of the recipient. For this phenotypic effect to occur, EVs need to fuse with target cell membranes, either directly with the plasma membrane or with the endosomal membrane after endocytic uptake. EVs are of therapeutic interest because they are deregulated in diseases such as cancer and they could be harnessed to deliver drugs to target cells. It is therefore important to understand the molecular mechanisms by which EVs are taken up into cells. This comprehensive review summarizes current knowledge of EV uptake mechanisms. Cells appear to take up EVs by a variety of endocytic pathways, including clathrin-dependent endocytosis, and clathrin-independent pathways such as caveolin-mediated uptake, macropinocytosis, phagocytosis, and lipid raft–mediated internalization. Indeed, it seems likely that a heterogeneous population of EVs may gain entry into a cell via more than one route. The uptake mechanism used by a given EV may depend on proteins and glycoproteins found on the surface of both the vesicle and the target cell. Further research is needed to understand the precise rules that underpin EV entry into cells.

  1. Freezing tolerance of conifer seeds and germinants.

    Science.gov (United States)

    Hawkins, B J; Guest, H J; Kolotelo, D

    2003-12-01

    Survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (Picea glauca x engelmannii complex), lodgepole pine (Pinus contorta Dougl. ex Loud.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western red cedar (Thuja plicata Donn ex D. Donn). Effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 16-h photoperiod and a 22/17 degrees C thermoperiod. Survival was related to the water content of seeds and germinants, germination rate and seedlot origin. After freezing for 3 h at -196 degrees C, dry seed of most seedlots of interior spruce, Douglas-fir and western red cedar had 84-96% germination, whereas lodgepole pine seedlots had 53-82% germination. Freezing tolerance declined significantly after imbibition in lodgepole pine, Douglas-fir and interior spruce seed (western red cedar was not tested), and mean LT50 of imbibed seed of these species was -30, -24.5 and -20 degrees C, respectively. Freezing tolerance continued to decline to a minimum LT50 of -4 to -7 degrees C after 10 days in a growth chamber for interior spruce, Douglas-fir and lodgepole pine, or after 15 days for western red cedar. Minimum freezing tolerance was reached at the stage of rapid hypocotyl elongation. In all species, a slight increase in freezing tolerance of germinants was observed once cotyledons emerged from the seed coat. The decrease in freezing tolerance during the transition from dry to germinating seed correlated with increases in seed water content. Changes in freezing tolerance between 10 and 30 days in the growth chamber were not correlated with seedling water content. Within a species, seedlots differed significantly in freezing tolerance after 2 or 5 days in the growth chamber. Because all seedlots of interior spruce and lodgepole pine germinated quickly, there was no correlation

  2. Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

    International Nuclear Information System (INIS)

    Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

    1976-01-01

    It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

  3. Seed germination and sowing options [Chapter 8

    Science.gov (United States)

    Tara Luna; Kim Wilkinson; R. Kasten Dumroese

    2009-01-01

    Seeds of many native species are challenging to germinate. One important thing a grower can do is learn as much as possible about the life history, ecology, and habitat of the species they wish to grow.What processes do seeds of this species go through in nature? Any observations will be valuable when trying to germinate and grow species that have little or no...

  4. Oxygen dependency of germinating Brassica seeds

    Science.gov (United States)

    Park, Myoung Ryoul; Hasenstein, Karl H.

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

  5. Mathematical model of seed germination process

    International Nuclear Information System (INIS)

    Gładyszewska, B.; Koper, R.; Kornarzyński, K.

    1999-01-01

    An analytical model of seed germination process was described. The model based on proposed working hypothesis leads - by analogy - to a law corresponding with Verhulst-Pearl's law, known from the theory of population kinetics. The model was applied to describe the germination kinetics of tomato seeds, Promyk field cultivar, biostimulated by laser treatment. Close agreement of experimental and model data was obtained [pl

  6. Multiple paths to similar germination behavior in Arabidopsis thaliana.

    Science.gov (United States)

    Burghardt, Liana T; Edwards, Brianne R; Donohue, Kathleen

    2016-02-01

    Germination timing influences plant fitness, and its sensitivity to temperature may cause it to change as climate shifts. These changes are likely to be complex because temperatures that occur during seed maturation and temperatures that occur post-dispersal interact to define germination timing. We used the model organism Arabidopsis thaliana to determine how flowering time (which defines seed-maturation temperature) and post-dispersal temperature influence germination and the expression of genetic variation for germination. Germination responses to temperature (germination envelopes) changed as seeds aged, or after-ripened, and these germination trajectories depended on seed-maturation temperature and genotype. Different combinations of genotype, seed-maturation temperature, and after-ripening produced similar germination envelopes. Likewise, different genotypes and seed-maturation temperatures combined to produce similar germination trajectories. Differences between genotypes were most likely to be observed at high and low germination temperatures. The germination behavior of some genotypes responds weakly to maternal temperature but others are highly plastic. We hypothesize that weak dormancy induction could synchronize germination of seeds dispersed at different times. By contrast, we hypothesize that strongly responsive genotypes may spread offspring germination over several possible germination windows. Considering germination responses to temperature is important for predicting phenology expression and evolution in future climates. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  7. Nicotinamidase activity is important for germination.

    Science.gov (United States)

    Hunt, Lee; Holdsworth, Michael J; Gray, Julie E

    2007-08-01

    It has been suggested that nicotinamide must be degraded during germination; however, the enzyme responsible and its physiological role have not been previously studied. We have identified an Arabidopsis gene, NIC2, that is expressed at relatively high levels in mature seed, and encodes a nicotinamidase enzyme with homology to yeast and bacterial nicotinamidases. Seed of a knockout mutant, nic2-1, had reduced nicotinamidase activity, retarded germination and impaired germination potential. nic2-1 germination was restored by after-ripening or moist chilling, but remained hypersensitive to application of nicotinamide or ABA. Nicotinamide is a known inhibitor of NAD-degrading poly(ADP-ribose) polymerases (PARP enzymes) that are implicated in DNA repair. We found reduced poly(ADP)ribosylation levels in nic2-1 seed, which were restored by moist chilling. Furthermore, nic2-1 seed had elevated levels of NAD, and germination was hypersensitive to methyl methanesulphonate (MMS), suggesting that PARP activity and DNA repair responses were impaired. We suggest that nicotinamide is normally metabolized by NIC2 during moist chilling or after-ripening, which relieves inhibition of PARP activity and allows DNA repair to occur prior to germination.

  8. Release of canine parvovirus from endocytic vesicles

    International Nuclear Information System (INIS)

    Suikkanen, Sanna; Antila, Mia; Jaatinen, Anne; Vihinen-Ranta, Maija; Vuento, Matti

    2003-01-01

    Canine parvovirus (CPV) is a small nonenveloped virus with a single-stranded DNA genome. CPV enters cells by clathrin-mediated endocytosis and requires an acidic endosomal step for productive infection. Virion contains a potential nuclear localization signal as well as a phospholipase A 2 like domain in N-terminus of VP1. In this study we characterized the role of PLA 2 activity on CPV entry process. PLA 2 activity of CPV capsids was triggered in vitro by heat or acidic pH. PLA 2 inhibitors inhibited the viral proliferation suggesting that PLA 2 activity is needed for productive infection. The N-terminus of VP1 was exposed during the entry, suggesting that PLA 2 activity might have a role during endocytic entry. The presence of drugs modifying endocytosis (amiloride, bafilomycin A 1 , brefeldin A, and monensin) caused viral proteins to remain in endosomal/lysosomal vesicles, even though the drugs were not able to inhibit the exposure of VP1 N-terminal end. These results indicate that the exposure of N-terminus of VP1 alone is not sufficient to allow CPV to proliferate. Some other pH-dependent changes are needed for productive infection. In addition to blocking endocytic entry, amiloride was able to block some postendocytic steps. The ability of CPV to permeabilize endosomal membranes was demonstrated by feeding cells with differently sized rhodamine-conjugated dextrans together with the CPV in the presence or in the absence of amiloride, bafilomycin A 1 , brefeldin A, or monensin. Dextran with a molecular weight of 3000 was released from vesicles after 8 h of infection, while dextran with a molecular weight of 10,000 was mainly retained in vesicles. The results suggest that CPV infection does not cause disruption of endosomal vesicles. However, the permeability of endosomal membranes apparently changes during CPV infection, probably due to the PLA 2 activity of the virus. These results suggest that parvoviral PLA 2 activity is essential for productive infection and

  9. Mean germination time and germination rate of oat seeds subjected to stationary magnetic field

    International Nuclear Information System (INIS)

    Martinez Ramirez, Elvira; Florez Garcia, Mercedes; Carbonell, Maria Victoria; Amaya Garcia de la Escosura, Jose Manuel

    2007-01-01

    The objective of the present study is to determine and quantify the effect produced by stationary magnetic fields on oat seed germination (Avena sativa, L. var. c obena ) . For this purpose, seeds were exposed to a magnetic field 125 mT of 250 mT during different periods of time: 20 minutes (E1, E5), 1 hour (E2, E6), 24 hours (E3, E7), or in a conic form (E4, E8) during the whole germination process. Germination tests were carried out under laboratory conditions with cylindrical magnets to obtain the magnetic field. For magnetic treatment seed on Petri dishes were placed on magnets during time necessary for each treatment. Seeds without exposition to the magnetic field were used as control group. Parameters used for germination speed analysis were: number of germinated seeds (G), mean germination time (MGT) and necessary time for germination of 1, 10, 25, 50 and 75% of N number of speeds used for each treatment (T1, T10, T25, T50, and T75). These parameters were supplied through the software Seed calculator, as well as the corresponding germination curves. In general, from the results obtained it can be said that the time required to obtain different germination percentages was lower for seeds exposed to the magnetic field (treatments E1 and E8). Reduction in time for E1 treatment stands up with 20 a minutes-exposition-time to 125 mT. MGT obtained for seeds with magnetic treatment E1 was significantly lower (11.48%) than the control group. Parameters T1, T10, T25 were also lower for seeds submitted to treatment, obtaining reductions of 46.62 %, 24.02 % and 13.46 % respectively. Reduction in germination parameters indicates that germination speed is higher. Because parameters T1 and T10 are related to the beginning of germination, this study represents a progress in germination and a reduction in the induction phase in most of the magnetic treatments applied. Previous studies done by authors about the influence of stationary magnetic fields have shown increases in

  10. Definition of spontaneous reconnection

    International Nuclear Information System (INIS)

    Schindler, K.

    1984-01-01

    The author discusses his view of driven versus spontaneous. There is a close link between ''spontaneous'' and ''instability.'' One of the prominent examples for instability is the thermal convection instability. Just to remind you, if you heat a fluid layer from below, it takes a certain Rayleigh number to make it unstable. Beyond the onset point you find qualitatively new features. That is called ''spontaneous,'' and this is a bit more than semantics. It's a new qualitative property that appears and it is spontaneous although we have an energy flux through the system. It's a misconception, to call this ''driven'' pointing at the energy flux through it. Of course, the convection would not exist without this energy flux. But what makes it ''spontaneous'' is that without any particular external signal, a new qualitative feature appears. And this is what is called an ''instability'' and ''spontaneous.'' From these considerations the author got a little reassured of what distinction should be made in the field of the magnetosphere. If we have a smooth energy transport into the magnetosphere and suddenly we have this qualitatively new feature (change of B-topology) coming up; then, using this terminology we don't have a choice other than calling this spontaneous or unstable, if you like. If we ''tell'' the system where it should make its neutral line and where it should make its plasmoids, then, it is driven. And this provides a very clear-cut observational distinction. The author emphasizes the difference he sees is a qualitative difference, not only a quantitative one

  11. Formation of Kinetically Trapped Nanoscopic Unilamellar Vesicles from Metastable Nanodiscs

    Energy Technology Data Exchange (ETDEWEB)

    Nieh, Mu-Ping [Univ. of Connecticut, Storrs, CT (United States). Inst. of Materials Science, Dept. of Chemical, Materials & Biomolecular Engineering; Dolinar, Paul [Univ. of Ottawa, ON (Canada); Kucerka, Norbert [National Research Council, Chalk River, ON (Canada). Chalk River Lab., Canadian Neutron Beam Centre; Comenius Univ., Bratislava (Slovakia). Dept. of Physical Chemistry of Drugs; Kline, Steven R. [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States); Debeer-Schmitt, Lisa M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Littrell, Kenneth C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Katsaras, John [National Research Council, Chalk River, ON (Canada). Chalk River Lab., Canadian Neutron Beam Centre; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Science Division; Brock Univ., St. Catharines, ON (Canada). Dept. of Physics; Univ. of Guelph, ON (Canada). Guelph-Waterloo Physics Inst.

    2011-09-27

    Zwitterionic long-chain lipids (e.g., dimyristoyl phosphatidylcholine, DMPC) spontaneously form onion-like, thermodynamically stable structures in aqueous solutions (commonly known as multilamellar vesicles, or MLVs). It has also been reported that the addition of zwitterionic short-chain (i.e., dihexanoyl phosphatidylcholine, DHPC) and charged long-chain (i.e., dimyristoyl phosphatidylglycerol, DMPG) lipids to zwitterionic long-chain lipid solutions results in the formation of unilamellar vesicles (ULVs). Here, we report a kinetic study on lipid mixtures composed of DMPC, DHPC, and DMPG. Two membrane charge densities (i.e., [DMPG]/[DMPC] = 0.01 and 0.001) and two solution salinities (i.e., [NaCl] = 0 and 0.2 M) are investigated. Upon dilution of the high-concentration samples at 50 °C, thermodynamically stable MLVs are formed, in the case of both weakly charged and high salinity solution mixtures, implying that the electrostatic interactions between bilayers are insufficient to cause MLVs to unbind. Importantly, in the case of these samples small angle neutron scattering (SANS) data show that, initially, nanodiscs (also known as bicelles) or bilayered ribbons form at low temperatures (i.e., 10 °C), but transform into uniform size, nanoscopic ULVs after incubation at 10 °C for 20 h, indicating that the nanodisc is a metastable structure. The instability of nanodiscs may be attributed to low membrane rigidity due to a reduced charge density and high salinity. Moreover, the uniform-sized ULVs persist even after being heated to 50 °C, where thermodynamically stable MLVs are observed. This result clearly demonstrates that these ULVs are kinetically trapped, and that the mechanical properties (e.g., bending rigidity) of 10 C nanodiscs favor the formation of nanoscopic ULVs over that of MLVs. From a practical point of view, this method of forming uniform-sized ULVs may lend itself to their mass production, thus making them economically feasible for medical

  12. Formation of Kinetically Trapped Nanoscopic Unilamellar Vesicles from Metastable Nanodiscs

    International Nuclear Information System (INIS)

    Nieh, Mu-Ping; Dolinar, Paul; Kucerka, Norbert; Kline, Steven R.; Debeer-Schmitt, Lisa M.; Littrell, Ken; Katsaras, John

    2011-01-01

    Zwitterionic long-chain lipids (e.g., dimyristoyl phosphatidylcholine, DMPC) spontaneously form onion-like, thermodynamically stable structures in aqueous solutions (commonly known as multilamellar vesicles, or MLVs). It has also been reported that the addition of zwitterionic short-chain (i.e., dihexanoyl phosphatidylcholine, DHPC) and charged long-chain (i.e., dimyristoyl phosphatidylglycerol, DMPG) lipids to zwitterionic long-chain lipid solutions results in the formation of unilamellar vesicles (ULVs). Here, we report a kinetic study on lipid mixtures composed of DMPC, DHPC, and DMPG. Two membrane charge densities (i.e., (DMPG)/(DMPC) = 0.01 and 0.001) and two solution salinities (i.e., (NaCl) = 0 and 0.2 M) are investigated. Upon dilution of the high-concentration samples at 50 C, thermodynamically stable MLVs are formed, in the case of both weakly charged and high salinity solution mixtures, implying that the electrostatic interactions between bilayers are insufficient to cause MLVs to unbind. Importantly, in the case of these samples small angle neutron scattering (SANS) data show that, initially, nanodiscs (also known as bicelles) or bilayered ribbons form at low temperatures (i.e., 10 C), but transform into uniform size, nanoscopic ULVs after incubation at 10 C for 20 h, indicating that the nanodisc is a metastable structure. The instability of nanodiscs may be attributed to low membrane rigidity due to a reduced charge density and high salinity. Moreover, the uniform-sized ULVs persist even after being heated to 50 C, where thermodynamically stable MLVs are observed. This result clearly demonstrates that these ULVs are kinetically trapped, and that the mechanical properties (e.g., bending rigidity) of 10 C nanodiscs favor the formation of nanoscopic ULVs over that of MLVs. From a practical point of view, this method of forming uniform-sized ULVs may lend itself to their mass production, thus making them economically feasible for medical applications that

  13. Rodent neonatal germinal matrix hemorrhage mimics the human brain injury, neurological consequences, and post-hemorrhagic hydrocephalus

    OpenAIRE

    Lekic, Tim; Manaenko, Anatol; Rolland, William; Krafft, Paul R.; Peters, Regina; Hartman, Richard E.; Altay, Orhan; Tang, Jiping; Zhang, John H.

    2012-01-01

    Germinal matrix hemorrhage (GMH) is the most common neurological disease of premature newborns. GMH causes neurological sequelae such as cerebral palsy, post-hemorrhagic hydrocephalus, and mental retardation. Despite this, there is no standardized animal model of spontaneous GMH using newborn rats to depict the condition. We asked whether stereotactic injection of collagenase type VII (0.3 U) into the ganglionic eminence of neonatal rats would reproduce the acute brain injury, gliosis, hydroc...

  14. Case of spontaneous ventriculocisternostomy

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru [Hiroshima Univ. (Japan). School of Medicine; Kuwabara, Satoshi

    1983-05-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH/sub 2/O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

  15. Germination of Avena fatua under different gaseous environments

    Energy Technology Data Exchange (ETDEWEB)

    Hart, J.W.; Berrie, A.M.M.

    1966-01-01

    The atmosphere in which seeds germinate can profoundly affect the level of germination and dormancy. Seeds were germinated in atmospheres containing various concentrations of carbon dioxide and oxygen. At the same time the effect of light on these systems was examined. The germination of partially dormant populations of wild oat seed is inhibited by white light. This response to light is most apparent when the caryopsis is enclosed in the pales. Investigations into the effect of the ambient atmosphere on germination have indicated that, while oxygen is a necessary factor in the germination of this species, carbon dioxide also has an effect. A lack of carbon dioxide increases the degree of light inhibition of germination; 3% carbon dioxide (by volume) allows germination in light; 20% carbon dioxide inhibits germination in light and darkness at all tested oxygen concentrations.

  16. Characterization of yeast extracellular vesicles: evidence for the participation of different pathways of cellular traffic in vesicle biogenesis.

    Directory of Open Access Journals (Sweden)

    Débora L Oliveira

    2010-06-01

    Full Text Available Extracellular vesicles in yeast cells are involved in the molecular traffic across the cell wall. In yeast pathogens, these vesicles have been implicated in the transport of proteins, lipids, polysaccharide and pigments to the extracellular space. Cellular pathways required for the biogenesis of yeast extracellular vesicles are largely unknown.We characterized extracellular vesicle production in wild type (WT and mutant strains of the model yeast Saccharomyces cerevisiae using transmission electron microscopy in combination with light scattering analysis, lipid extraction and proteomics. WT cells and mutants with defective expression of Sec4p, a secretory vesicle-associated Rab GTPase essential for Golgi-derived exocytosis, or Snf7p, which is involved in multivesicular body (MVB formation, were analyzed in parallel. Bilayered vesicles with diameters at the 100-300 nm range were found in extracellular fractions from yeast cultures. Proteomic analysis of vesicular fractions from the cells aforementioned and additional mutants with defects in conventional secretion pathways (sec1-1, fusion of Golgi-derived exocytic vesicles with the plasma membrane; bos1-1, vesicle targeting to the Golgi complex or MVB functionality (vps23, late endosomal trafficking revealed a complex and interrelated protein collection. Semi-quantitative analysis of protein abundance revealed that mutations in both MVB- and Golgi-derived pathways affected the composition of yeast extracellular vesicles, but none abrogated vesicle production. Lipid analysis revealed that mutants with defects in Golgi-related components of the secretory pathway had slower vesicle release kinetics, as inferred from intracellular accumulation of sterols and reduced detection of these lipids in vesicle fractions in comparison with WT cells.Our results suggest that both conventional and unconventional pathways of secretion are required for biogenesis of extracellular vesicles, which demonstrate the

  17. Neuronal Depolarization Drives Increased Dopamine Synaptic Vesicle Loading via VGLUT.

    Science.gov (United States)

    Aguilar, Jenny I; Dunn, Matthew; Mingote, Susana; Karam, Caline S; Farino, Zachary J; Sonders, Mark S; Choi, Se Joon; Grygoruk, Anna; Zhang, Yuchao; Cela, Carolina; Choi, Ben Jiwon; Flores, Jorge; Freyberg, Robin J; McCabe, Brian D; Mosharov, Eugene V; Krantz, David E; Javitch, Jonathan A; Sulzer, David; Sames, Dalibor; Rayport, Stephen; Freyberg, Zachary

    2017-08-30

    The ability of presynaptic dopamine terminals to tune neurotransmitter release to meet the demands of neuronal activity is critical to neurotransmission. Although vesicle content has been assumed to be static, in vitro data increasingly suggest that cell activity modulates vesicle content. Here, we use a coordinated genetic, pharmacological, and imaging approach in Drosophila to study the presynaptic machinery responsible for these vesicular processes in vivo. We show that cell depolarization increases synaptic vesicle dopamine content prior to release via vesicular hyperacidification. This depolarization-induced hyperacidification is mediated by the vesicular glutamate transporter (VGLUT). Remarkably, both depolarization-induced dopamine vesicle hyperacidification and its dependence on VGLUT2 are seen in ventral midbrain dopamine neurons in the mouse. Together, these data suggest that in response to depolarization, dopamine vesicles utilize a cascade of vesicular transporters to dynamically increase the vesicular pH gradient, thereby increasing dopamine vesicle content. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Deformation of phospholipid vesicles in an optical stretcher

    OpenAIRE

    Delabre , Ulysse; Feld , Kasper; Crespo , Eleonore; Whyte , Graeme; Sykes , Cecile; Seifert , Udo; Guck , Jochen

    2015-01-01

    International audience; Phospholipid vesicles are common model systems for cell membranes. Important aspects of the membrane function relate to its mechanical properties. Here we have investigated the deformation behaviour of phospholipid vesicles in a dual-beam laser trap, also called an optical stretcher. This study explicitly makes use of the inherent heating present in such traps to investigate the dependence of vesicle deformation on temperature. By using lasers with different wavelength...

  19. Spontaneous tension haemopneumothorax.

    Science.gov (United States)

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-10-31

    We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  20. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  1. Spontaneous tension haemopneumothorax

    Directory of Open Access Journals (Sweden)

    Itam Sarah

    2008-10-01

    Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  2. ABC Triblock Copolymer Vesicles with Mesh-like Morphology

    Science.gov (United States)

    Zhao, Wei; Russell, Thomas; Grason, Gregory

    2010-03-01

    Polymer vesicles can be made from poly(isoprene-b-styrene-b-2-vinylpyridene) (PI-b-PS-b-P2VP) triblock copolymer under the confinement of anodic aluminum oxide (AAO) membrane. It was found that these vesicles have well-defined, nanoscopic size and a microphase-separated hydrophobic core, comprised of PS and PI blocks. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the core at a well-defined composition of three blocks. Confinement played an important role in generating these vesicles with such an unusual morphology.

  3. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles.

    Science.gov (United States)

    Lässer, Cecilia; Théry, Clotilde; Buzás, Edit I; Mathivanan, Suresh; Zhao, Weian; Gho, Yong Song; Lötvall, Jan

    2016-01-01

    The International Society for Extracellular Vesicles (ISEV) has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs). This course, "Basics of Extracellular Vesicles," uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC) on EVs was launched on 15 August 2016 at the platform "Coursera" and is free of charge.

  4. The International Society for Extracellular Vesicles launches the first massive open online course on extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Cecilia Lässer

    2016-12-01

    Full Text Available The International Society for Extracellular Vesicles (ISEV has organised its first educational online course for students and beginners in the field of extracellular vesicles (EVs. This course, “Basics of Extracellular Vesicles,” uses recorded lectures from experts in the field and will be open for an unlimited number of participants. The course is divided into 5 modules and can be accessed at www.coursera.org/learn/extracellular-vesicles. The first module is an introduction to the field covering the nomenclature and history of EVs. Module 2 focuses on the biogenesis and uptake mechanisms of EVs, as well as their RNA, protein and lipid cargo. Module 3 covers the collection and processing of cell culture media and body fluids such as blood, breast milk, cerebrospinal fluid and urine prior to isolation of EVs. Modules 4 and 5 present different isolation methods and characterisation techniques utilised in the EV field. Here, differential ultracentrifugation, size-exclusion chromatography, density gradient centrifugation, kit-based precipitation, electron microscopy, cryo-electron microscopy, flow cytometry, atomic-force microscopy and nanoparticle-tracking analysis are covered. This first massive open online course (MOOC on EVs was launched on 15 August 2016 at the platform “Coursera” and is free of charge.

  5. Sugar-Decorated Sugar Vesicles : Lectin-Carbohydrate Recognition at the Surface of Cyclodextrin Vesicles

    NARCIS (Netherlands)

    Voskuhl, Jens; Stuart, Marc C. A.; Ravoo, Bart Jan

    2010-01-01

    An artificial glycocalix self-assembles when unilamellar bilayer vesicles of amphiphilic beta-cyclodextrins are decorated with maltose and lactose by host-guest interactions. To this end, maltose and lactose were conjugated with adamantane through a tetra(ethyleneglycol) spacer. Both

  6. Cyrtopodium paludicolum germination with two Tulasnella isolates

    Directory of Open Access Journals (Sweden)

    Otieres Cirino de Carvalho

    2017-11-01

    Full Text Available ABSTRACT Symbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. The aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its efficiency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01 and Epidendrum secundum (M65, which has been successfully used a number of times in symbiotic germination. The experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. The mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identified as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specificity in the relationship between Cyrtopodium paludicolum and the fungi. The results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.

  7. Additive effects on the energy barrier for synaptic vesicle fusion cause supralinear effects on the vesicle fusion rate

    DEFF Research Database (Denmark)

    Schotten, Sebastiaan; Meijer, Marieke; Walter, Alexander Matthias

    2015-01-01

    supralinear effects on the fusion rate. To test this prediction experimentally, we developed a method to assess the number of releasable vesicles, rate constants for vesicle priming, unpriming, and fusion, and the activation energy for fusion by fitting a vesicle state model to synaptic responses induced......-linear effects of genetic/pharmacological perturbations on synaptic transmission and a novel interpretation of the cooperative nature of Ca2+-dependent release....

  8. Combining Ability for Germination Traits in Jatropha curcas L.

    Directory of Open Access Journals (Sweden)

    A. K. M. Aminul Islam

    2013-01-01

    Full Text Available Six parents of Jatropha curcas were crossed in half diallel fashion, and the F1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA and specific combining ability (SCA variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P1 and P2 were the best general combiner for most of the characters studied. The cross P1×P5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P2×P5 for mean germination time, time of 50% germination, and seedling length, and the cross P4×P5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96% was observed in hybrid P2×P4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI and seedling vigor index (SVI were found in hybrid P1×P5 and P2×P5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.

  9. Spontaneous rib fractures.

    Science.gov (United States)

    Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

    2015-07-01

    Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

  10. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  11. Chickpea seeds germination rational parameters optimization

    Science.gov (United States)

    Safonova, Yu A.; Ivliev, M. N.; Lemeshkin, A. V.

    2018-05-01

    The paper presents the influence of chickpea seeds bioactivation parameters on their enzymatic activity experimental results. Optimal bioactivation process modes were obtained by regression-factor analysis: process temperature - 13.6 °C, process duration - 71.5 h. It was found that in the germination process, the proteolytic, amylolytic and lipolytic enzymes activity increased, and the urease enzyme activity is reduced. The dependences of enzyme activity on chickpea seeds germination conditions were obtained by mathematical processing of experimental data. The calculated data are in good agreement with the experimental ones. This confirms the optimization efficiency based on experiments mathematical planning in order to determine the enzymatic activity of chickpea seeds germination optimal parameters of bioactivated seeds.

  12. Nonenzymatic glycation of phosphatidylethanolamine in erythrocyte vesicles

    International Nuclear Information System (INIS)

    Patkowska, M.J.; Horowitz, M.I.

    1986-01-01

    Unsealed inside-out and right-side out vesicles were prepared from human red cells. The vesicles were incubated with D-glucose [ 14 C(U)] and sodium cyanoborohydride in phosphate buffer, pH 7.4. After incubation, lipids were extracted with 1-butanol and non-lipid contaminants removed by Sephadex G-25 chromatography. Phosphatidylethanolamine-sorbitol was purified by chromatography on columns of silicic acid and phenylboronate agarose gel. Phospholipase C (B. cereus) liberated phosphoethanolamine-sorbitol (I) which comigrated on TLC with synthetic I prepared by reductive condensation of phosphoethanolamine and D-glucose and also with the product of phospholipase C (B. cereus) hydrolysis of reference phosphatidylethanolamine-sorbitol. Exposure of I to alkaline phosphatase (E. coli) gave P/sub i/ and ethanolamine-sorbitol (II) which comigrated on TLC with synthetic II prepared by reductive condensation of ethanolamine and D-glucose or by phospholipase D hydrolysis of reference phosphatidylethanolamine-sorbitol. These studies demonstrate that vesicular phosphatidylethanolamine can be reductively glycated and illustrate the applicability of both phospholipase C and phospholipase D in characterizing glycated phosphoglycerides

  13. Mechanical collapse of confined fluid membrane vesicles.

    Science.gov (United States)

    Rim, Jee E; Purohit, Prashant K; Klug, William S

    2014-11-01

    Compact cylindrical and spherical invaginations are common structural motifs found in cellular and developmental biology. To understand the basic physical mechanisms that produce and maintain such structures, we present here a simple model of vesicles in confinement, in which mechanical equilibrium configurations are computed by energy minimization, balancing the effects of curvature elasticity, contact of the membrane with itself and the confining geometry, and adhesion. For cylindrical confinement, the shape equations are solved both analytically and numerically by finite element analysis. For spherical confinement, axisymmetric configurations are obtained numerically. We find that the geometry of invaginations is controlled by a dimensionless ratio of the adhesion strength to the bending energy of an equal area spherical vesicle. Larger adhesion produces more concentrated curvatures, which are mainly localized to the "neck" region where the invagination breaks away from its confining container. Under spherical confinement, axisymmetric invaginations are approximately spherical. For extreme confinement, multiple invaginations may form, bifurcating along multiple equilibrium branches. The results of the model are useful for understanding the physical mechanisms controlling the structure of lipid membranes of cells and their organelles, and developing tissue membranes.

  14. Autotoxicity of chard and its allelopathic potentiality on germination ...

    African Journals Online (AJOL)

    SERVER

    2008-04-03

    Apr 3, 2008 ... Abbreviation: (W+C), Wheat germinated with chard; (C+W), chard germinated with ..... hull extracts which have inhibitory effect on the growth of barnyardgrass seedlings. .... John Wiley and Sons,. New York, pp. 171-188.

  15. Potential germination and initial growth of Sclerocarya birrea (A ...

    African Journals Online (AJOL)

    SARAH

    2014-04-30

    Apr 30, 2014 ... Methodology: The parameters studied for the germination test were: latency duration, germination capacity .... for family consumption or in the cosmetic industry. (Murray ... the crowns of trees and in the stall of the animals.

  16. Effect of chromium toxicity on germination and early seedling growth ...

    African Journals Online (AJOL)

    USER

    2010-07-19

    Jul 19, 2010 ... germination and early seedling growth of melon (Cucumis melo L.). Chromium ... chromium on seed germination and seedling growth- biomass in early ..... such critical regulatory mechanisms are likely to operate in seeds at ...

  17. on seed germination and growth of Garcinia kola

    African Journals Online (AJOL)

    SARAH

    2016-07-31

    Jul 31, 2016 ... Parameters related to seed germination and seedlings vigour was evaluated. Results indicated that substrate do not affect seed germination and plant vigour. However ..... Annual plant reviews California, USA, pp. 50-. 6.7.

  18. Studies on seed germination and in vitro shoot multiplication of ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... vitro seed germination and plantlet regeneration of this plant. ... Key words: Germination, gibberellic acid, growth regulators, node explants, Satureja ..... Abscisic Acid: A. Seed Maturation and Antistress Signal, 3rd ed. Sinauer ...

  19. Factors Defining Field Germination of Oilseed Radish Seeds

    Directory of Open Access Journals (Sweden)

    N.V. Dorofeev

    2013-08-01

    Full Text Available Influence of temperature, depth of crops and granulometric of soil structure on germination speed, laboratory and field germination of oilseed radish seeds were studied. It was established that the period of seed-germination is defined both by temperature and granulometric structure of soil. The highest field germination was marked on sandy loam at depth of crops' seeds at 3 cm and 20°С.

  20. Comparative proteomic analysis of extracellular vesicles isolated by acoustic trapping or differential centrifugation

    NARCIS (Netherlands)

    Rezeli, Melinda; Gidlöf, Olof; Evander, Mikael; Bryl-Górecka, Paulina; Sathanoori, Ramasri; Gilje, Patrik; Pawlowski, Krzysztof; Horvatovich, Péter; Erlinge, David; Marko-Varga, György; Laurell, Thomas

    2016-01-01

    Extracellular vesicles (ECVs), including microparticles (MPs) and exosomes, are submicron membrane vesicles released by diverse cell types upon activation or stress. Circulating ECVs are potential reservoirs of disease biomarkers, and the complexity of these vesicles is significantly lower compared

  1. Getting there: vesicles en route for plant cytokinesis

    NARCIS (Netherlands)

    Ozdoba, A.

    2007-01-01

    In dividing plant cells, membranous vesicles (60-80 nm in diameter) are transported to the site where a new cell wall that separates the daughter cells is formed. In this thesis the physical parameters size and stiffness that vesicles require to reach the forming cell plate were studied. Synthetic

  2. Loading of Vesicles into Soft Amphiphilic Nanotubes using Osmosis

    NARCIS (Netherlands)

    Erne, Petra M.; van Bezouwen, Laura S.; Stacko, Peter; van Dtjken, Derk Jan; Chen, Jiawen; Stuart, Marc C. A.; Boekema, Eghert J.; Feringa, Ben L.

    2015-01-01

    The facile assembly of higher-order nanoarchitectures from simple building blocks is demonstrated by the loading of vesicles into soft amphiphilic nanotubes using osmosis. The nanotubes are constructed from rigid interdigitated bilayers which are capped with vesicles comprising phospholipid-based

  3. Slow sedimentation and deformability of charged lipid vesicles.

    Directory of Open Access Journals (Sweden)

    Iván Rey Suárez

    Full Text Available The study of vesicles in suspension is important to understand the complicated dynamics exhibited by cells in in vivo and in vitro. We developed a computer simulation based on the boundary-integral method to model the three dimensional gravity-driven sedimentation of charged vesicles towards a flat surface. The membrane mechanical behavior was modeled using the Helfrich Hamiltonian and near incompressibility of the membrane was enforced via a model which accounts for the thermal fluctuations of the membrane. The simulations were verified and compared to experimental data obtained using suspended vesicles labelled with a fluorescent probe, which allows visualization using fluorescence microscopy and confers the membrane with a negative surface charge. The electrostatic interaction between the vesicle and the surface was modeled using the linear Derjaguin approximation for a low ionic concentration solution. The sedimentation rate as a function of the distance of the vesicle to the surface was determined both experimentally and from the computer simulations. The gap between the vesicle and the surface, as well as the shape of the vesicle at equilibrium were also studied. It was determined that inclusion of the electrostatic interaction is fundamental to accurately predict the sedimentation rate as the vesicle approaches the surface and the size of the gap at equilibrium, we also observed that the presence of charge in the membrane increases its rigidity.

  4. Model of separated form factors for unilamellar vesicles

    International Nuclear Information System (INIS)

    Kiselev, M.A.; Aksenov, V.L.; Lesieur, P.; Lombardo, D.; Kiselev, A.M.

    2001-01-01

    A new model of separated form factors is proposed for the evaluation of small-angle neutron scattering curves from large unilamellar vesicles. The validity of the model was checked via comparison with the model of a hollow sphere. The model of separated form factors and the hollow sphere model give a reasonable agreement in the evaluation of vesicle parameters

  5. Molecular dynamics simulations of lipid vesicle fusion in atomic detail

    NARCIS (Netherlands)

    Knecht, Volker; Marrink, Siewert-Jan

    The fusion of a membrane-bounded vesicle with a target membrane is a key step in intracellular trafficking, exocytosis, and drug delivery. Molecular dynamics simulations have been used to study the fusion of small unilamellar vesicles composed of a dipalmitoyl-phosphatidylcholine (DPPC)/palmitic

  6. The freezing process of small lipid vesicles at molecular resolution

    NARCIS (Netherlands)

    Risselada, H. Jelger; Marrink, Siewert J.

    2009-01-01

    At present very little is known about the kinetic barriers which a small vesicle will face during the transformation from the liquid-crystalline to the gel phase, and what the structure of frozen vesicles looks like at the molecular level. The formation of gel domains in the strongly curved bilayer

  7. Asymmetric incorporation of Na+, K+-ATPase into phospholipid vesicles

    NARCIS (Netherlands)

    Jackson, R.L.; Verkleij, A.J.; Zoelen, E.J.J. van; Lane, L.K.; Schwartz, A.; Deenen, L.L.M. van

    Purified lamb kidney Na+, K+-ATPase, consisting solely of the Mτ = 95,000 catalytic subunit and the Mτ- 44,000 glycoprotein, was solubilized with Triton X-100 and incorporated into unilamellar phospholipid vesicles. Freeze-fracture electron microscopy of the vesicles showed intramembranous particles

  8. Organic Nano vesicular Cargoes for Sustained Drug Delivery: Synthesis, Vesicle Formation, Controlling “Pearling” States, and Terfenadine Loading/Release Studies

    International Nuclear Information System (INIS)

    Botcha, A.K.; Chandrasekar, R.; Dulla, B.; Reddy, E.R.; Rajadurai, M.S.; Chennubhotla, K.S.; Kulkarni, P.; Kulkarni, P.

    2014-01-01

    “Sustained drug delivery systems” which are designed to accomplish long-lasting therapeutic effect are one of the challenging topics in the area of nano medicine. We developed an innovative strategy to prepare nontoxic and polymer stabilized organic nano vesicles (diameter: 200 nm) from a novel bolaamphiphile, where two hydrogen bonding acetyl cytosine molecules connected to 4,4′′-positions of the 2,6-bispyrazolylpyridine through two flexible octyne chains. The nano vesicles behave like biological membrane by spontaneously self-assembling into “pearl-like” chains and subsequently forming long nano tubes (diameter: 150 nm), which further develop into various types of network-junctions through self-organization. For drug loading and delivery applications, the nano vesicles were externally protected with biocompatible poly(ethyleneglycol)-2000 to prevent them from fusion and ensuing tube formation. Nontoxic nature of the nano vesicles was demonstrated by zebra fish teratogenicity assay. Biocompatible nano vesicles were loaded with “terfenadine” drug and successfully utilized to transport and release drug in sustained manner (up to 72 h) in zebra fish larvae, which is recognized as an emerging in vivo model system Synthetic nano

  9. DOG1-imposed dormancy mediates germination responses to temperature cues

    NARCIS (Netherlands)

    Murphey, M.; Kovach, K.; Elnacash, T.; He, H.; Bentsink, L.; Donohue, K.

    2015-01-01

    Seed dormancy and environment-dependent germination requirements interact to determine the timing of germination in natural environments. This study tested the contribution of the dormancy gene Delay Of Germination 1 (DOG1) to primary and secondary dormancy induction in response to environmental

  10. Monte Carlo simulation of the seed germination process

    International Nuclear Information System (INIS)

    Gladyszewska, B.; Koper, R.

    2000-01-01

    Paper presented a mathematical model of seed germination process based on the Monte Carlo method and theoretical premises resulted from the physiology of seed germination suggesting three consecutive stages: physical, biochemical and physiological. The model was experimentally verified by determination of germination characteristics for seeds of ground tomatoes, Promyk cultivar, within broad range of temperatures (from 15 to 30 deg C)

  11. Factors affecting the germination of hybrid rose achenes

    NARCIS (Netherlands)

    Vries, De D.P.; Dubois, L.A.M.

    2015-01-01

    The smooth germination of mature Hybrid rose achenes is hampered by (i) hardseededness (HS), (ii) primary dormancy (PD) and (iii) germination polymorphism (GP). HS is owing to the hard pericarp. PD is, in principle, a natural phenomenon that protects the seeds from precocious germination. For

  12. Biorhythms in conifer seed germination during extended storage

    Science.gov (United States)

    James P. Barnett; N.I. Marnonov

    1989-01-01

    A proportion of sound seeds of conifer species do not germinate during certain periods of the year, even when conditions are favorable. Mamonov et al. (1986) report that the non-germinating seeds have apparently undergone physiological changes that affected germination. This phenomenon may be due to seasonal periodicity, or biorhythms. As early as the mid-1930'...

  13. Comparison of Germination and Viability Tests for Southern Hardwood Seed

    Science.gov (United States)

    F. T. Bonner; J. L. Gammage

    1967-01-01

    This paper summarizes a 3-year evaluation of 10 methods for testing germinability and viability of the seed of six species of southern hardwood. In five of the methods, the seeds were germinated. In the others, visual, biochemical, or physical properties were the criteria. Cutting tests were best for sweetgum and Nuttall oak seed, while cutting or water germination...

  14. Effect of fungicides on Wyoming big sagebrush seed germination

    Science.gov (United States)

    Robert D. Cox; Lance H. Kosberg; Nancy L. Shaw; Stuart P. Hardegree

    2011-01-01

    Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different...

  15. Asymbiotic germination of immature embryos of a medicinally ...

    African Journals Online (AJOL)

    H.piri

    La germination no simuotica de las semillas de orquideas. Bol. Real. Soc. Esp. Hist. Nat. 21:250-260. Knudson L (1922). Non–symbiotic germination of orchid seeds. Bot. Gaz. 73:1-25. Knudson L (1925). Physiological study of the asymbiotic germination of orchid seeds. Bot. Gaz. 79:345-379. Lawler LJ (1984). Ethnobotany ...

  16. Membrane Protrusion Coarsening and Nanotubulation within Giant Unilamellar Vesicles

    KAUST Repository

    Węgrzyn, Ilona

    2011-11-16

    Hydrophobic side groups on a stimuli-responsive polymer, encapsulated within a single giant unilamellar vesicle, enable membrane attachment during compartment formation at elevated temperatures. We thermally modulated the vesicle through implementation of an IR laser via an optical fiber, enabling localized directed heating. Polymer-membrane interactions were monitored using confocal imaging techniques as subsequent membrane protrusions occurred and lipid nanotubes formed in response to the polymer hydrogel contraction. These nanotubes, bridging the vesicle membrane to the contracting hydrogel, were retained on the surface of the polymer compartment, where they were transformed into smaller vesicles in a process reminiscent of cellular endocytosis. This development of a synthetic vesicle system containing a stimuli-responsive polymer could lead to a new platform for studying inter/intramembrane transport through lipid nanotubes. © 2011 American Chemical Society.

  17. ISEV position paper: extracellular vesicle RNA analysis and bioinformatics

    Directory of Open Access Journals (Sweden)

    Andrew F. Hill

    2013-12-01

    Full Text Available Extracellular vesicles (EVs are the collective term for the various vesicles that are released by cells into the extracellular space. Such vesicles include exosomes and microvesicles, which vary by their size and/or protein and genetic cargo. With the discovery that EVs contain genetic material in the form of RNA (evRNA has come the increased interest in these vesicles for their potential use as sources of disease biomarkers and potential therapeutic agents. Rapid developments in the availability of deep sequencing technologies have enabled the study of EV-related RNA in detail. In October 2012, the International Society for Extracellular Vesicles (ISEV held a workshop on “evRNA analysis and bioinformatics.” Here, we report the conclusions of one of the roundtable discussions where we discussed evRNA analysis technologies and provide some guidelines to researchers in the field to consider when performing such analysis.

  18. Interaction of a potyviral VPg with anionic phospholipid vesicles

    International Nuclear Information System (INIS)

    Rantalainen, Kimmo I.; Christensen, Peter A.; Hafren, Anders; Otzen, Daniel E.; Kalkkinen, Nisse; Maekinen, Kristiina

    2009-01-01

    The viral genome-linked protein (VPg) of Potato virus A (PVA) is a multifunctional protein that belongs to a class of intrinsically disordered proteins. Typically, this type of protein gains a more stable structure upon interactions or posttranslational modifications. In a membrane lipid strip overlay binding assay, PVA VPg was found to bind phosphatidylserine (PS), but not phosphatidylcholine (PC). According to circular dichroism spectroscopy, the secondary structure of PVA VPg was stabilized upon interactions with PS and phosphatidylglycerol (PG), but not with PC vesicles. It is possible that this stabilization favored the formation of α-helical structures. Limited tryptic digestion showed that the interaction with anionic vesicles protected certain, otherwise accessible, trypsin cleavage sites. An electron microscopy study revealed that interaction with VPg substantially increased the vesicle diameter and caused the formation of pore or plaque-like electron dense spots on the vesicle surface, which gradually led to disruption of the vesicles.

  19. Practical aspects of temperature intervention in germination and post-germination development of bacterial spores

    International Nuclear Information System (INIS)

    Stastna, J.; Vinter, V.; Babicka, J.

    1974-01-01

    Temperature dependence of germination and post-germination growth was studied in the spores of B a c i l l u s c e r e u s NCIB 8122. It was found that a temperature of 5 0 C slowed down germination, with the cells showing the capacity of synthetizing only a limited amount of proteins. The synthesis of the cellular wall, however, went on for another few hours. Thick-walled, less permeable and less metabolically active cells formed having an altered ultrastructure. A prolonged cultivation at 30 0 C resulted in the reduction of living cells while the low cultivation temperature (5 0 C) was found to have a protective effect. Pre-irradiation with 30g krad of gamma radiation increased the sensitivity of surviving cells to the cultivation conditions. Spores in the post-germination period were found to be much more resistent and alternating use of low and higher temperatures had little effect on growth

  20. Low-resolution simulations of vesicle suspensions in 2D

    Science.gov (United States)

    Kabacaoğlu, Gökberk; Quaife, Bryan; Biros, George

    2018-03-01

    Vesicle suspensions appear in many biological and industrial applications. These suspensions are characterized by rich and complex dynamics of vesicles due to their interaction with the bulk fluid, and their large deformations and nonlinear elastic properties. Many existing state-of-the-art numerical schemes can resolve such complex vesicle flows. However, even when using provably optimal algorithms, these simulations can be computationally expensive, especially for suspensions with a large number of vesicles. These high computational costs can limit the use of simulations for parameter exploration, optimization, or uncertainty quantification. One way to reduce the cost is to use low-resolution discretizations in space and time. However, it is well-known that simply reducing the resolution results in vesicle collisions, numerical instabilities, and often in erroneous results. In this paper, we investigate the effect of a number of algorithmic empirical fixes (which are commonly used by many groups) in an attempt to make low-resolution simulations more stable and more predictive. Based on our empirical studies for a number of flow configurations, we propose a scheme that attempts to integrate these fixes in a systematic way. This low-resolution scheme is an extension of our previous work [51,53]. Our low-resolution correction algorithms (LRCA) include anti-aliasing and membrane reparametrization for avoiding spurious oscillations in vesicles' membranes, adaptive time stepping and a repulsion force for handling vesicle collisions and, correction of vesicles' area and arc-length for maintaining physical vesicle shapes. We perform a systematic error analysis by comparing the low-resolution simulations of dilute and dense suspensions with their high-fidelity, fully resolved, counterparts. We observe that the LRCA enables both efficient and statistically accurate low-resolution simulations of vesicle suspensions, while it can be 10× to 100× faster.

  1. Spontaneous tension haemopneumothorax

    OpenAIRE

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-01-01

    Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such c...

  2. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  3. Proteomics of Arabidopsis seed germination and priming

    NARCIS (Netherlands)

    Gallardo, K.; Job, C.; Groot, S.P.C.; Puype, M.; Demol, H.; Vandekerckhove, J.; Job, D.

    2003-01-01

    To better understand seed germination, a complex developmental process, we developed a proteome analysis of the model plant Arabidopsis for which complete genome sequence is now available. Among about 1,300 total seed proteins resolved in two-dimensional gels, changes in the abundance (up- and

  4. Seed dormancy and germination : light and nitrate

    NARCIS (Netherlands)

    Hilhorst, H.W.M.

    1990-01-01

    One of the most important aspects of the life cycle of seed plants is the formation and development of seeds on the motherplant and the subsequent dispersal. An equally important element of the survival strategy is the ability of seeds to prevent germination in unfavorable

  5. Changes in germination characteristics and seedling growth ...

    African Journals Online (AJOL)

    Yomi

    2012-03-06

    Mar 6, 2012 ... Priming provides controlled hydration of seeds to a level ... water but drying them before complete germination. .... compared with the control, although, this difference was ... membrane damage, and restores germ inability to aged .... lipid per oxidation in bitter gourd seeds and effects of priming and hot.

  6. Unravelling desiccation tolerance in germinated Arabidopsis seeds

    NARCIS (Netherlands)

    Maia de Oliveira, J.

    2014-01-01

    How different organisms survive in the absence or under very limited amounts of water is still an open question. The aim of the research presented in this thesis is to explore the molecular basis of desiccation tolerance in seeds. We investigated the possibilities of using germinated desiccation

  7. Spontaneous polyploidization in cucumber.

    Science.gov (United States)

    Ramírez-Madera, Axel O; Miller, Nathan D; Spalding, Edgar P; Weng, Yiqun; Havey, Michael J

    2017-07-01

    This is the first quantitative estimation of spontaneous polyploidy in cucumber and we detected 2.2% polyploids in a greenhouse study. We provide evidence that polyploidization is consistent with endoreduplication and is an on-going process during plant growth. Cucumber occasionally produces polyploid plants, which are problematic for growers because these plants produce misshaped fruits with non-viable seeds. In this study, we undertook the first quantitative study to estimate the relative frequency of spontaneous polyploids in cucumber. Seeds of recombinant inbred lines were produced in different environments, plants were grown in the field and greenhouse, and flow cytometry was used to establish ploidies. From 1422 greenhouse-grown plants, the overall relative frequency of spontaneous polyploidy was 2.2%. Plants possessed nuclei of different ploidies in the same leaves (mosaic) and on different parts of the same plant (chimeric). Our results provide evidence of endoreduplication and polysomaty in cucumber, and that it is an on-going and dynamic process. There was a significant effect (p = 0.018) of seed production environment on the occurrence of polyploid plants. Seed and seedling traits were not accurate predictors of eventual polyploids, and we recommend that cucumber producers rogue plants based on stature and leaf serration to remove potential polyploids.

  8. A perspective on extracellular vesicles proteomics

    Science.gov (United States)

    Rosa-Fernandes, Livia; Rocha, Victória Bombarda; Carregari, Victor Corasolla; Urbani, Andrea; Palmisano, Giuseppe

    2017-11-01

    Increasing attention has been given to secreted extracellular vesicles (EVs) in the past decades, especially in the portrayal of their molecular cargo and role as messengers in both homeostasis and pathophysiological conditions. This review presents the state-of-the-art proteomic technologies to identify and quantify EVs proteins along with their PTMs, interacting partners and structural details. The rapid growth of mass spectrometry-based analytical strategies for protein sequencing, PTMs and structural characterization has improved the level of molecular details that can be achieve from limited amount of EVs isolated from different biological sources. Here we will provide a perspective view on the achievements and challenges on EVs proteome characterization using mass spectrometry. A detailed bioinformatics approach will help us to picture the molecular fingerprint of EVs and understand better their pathophysiological function.

  9. Gas Vesicle Nanoparticles for Antigen Display

    Directory of Open Access Journals (Sweden)

    Shiladitya DasSarma

    2015-09-01

    Full Text Available Microorganisms like the halophilic archaeon Halobacterium sp. NRC-1 produce gas-filled buoyant organelles, which are easily purified as protein nanoparticles (called gas vesicles or GVNPs. GVNPs are non-toxic, exceptionally stable, bioengineerable, and self-adjuvanting. A large gene cluster encoding more than a dozen proteins has been implicated in their biogenesis. One protein, GvpC, found on the exterior surface of the nanoparticles, can accommodate insertions near the C-terminal region and results in GVNPs displaying the inserted sequences on the surface of the nanoparticles. Here, we review the current state of knowledge on GVNP structure and biogenesis as well as available studies on immunogenicity of pathogenic viral, bacterial, and eukaryotic proteins and peptides displayed on the nanoparticles. Recent improvements in genetic tools for bioengineering of GVNPs are discussed, along with future opportunities and challenges for development of vaccines and other applications.

  10. Morphometric image analysis of giant vesicles

    DEFF Research Database (Denmark)

    Husen, Peter Rasmussen; Arriaga, Laura; Monroy, Francisco

    2012-01-01

    We have developed a strategy to determine lengths and orientations of tie lines in the coexistence region of liquid-ordered and liquid-disordered phases of cholesterol containing ternary lipid mixtures. The method combines confocal-fluorescence-microscopy image stacks of giant unilamellar vesicles...... (GUVs), a dedicated 3D-image analysis, and a quantitative analysis based in equilibrium thermodynamic considerations. This approach was tested in GUVs composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine/1,2-palmitoyl-sn-glycero-3-phosphocholine/cholesterol. In general, our results show a reasonable...... agreement with previously reported data obtained by other methods. For example, our computed tie lines were found to be nonhorizontal, indicating a difference in cholesterol content in the coexisting phases. This new, to our knowledge, analytical strategy offers a way to further exploit fluorescence...

  11. Periodic-cylinder vesicle with minimal energy

    International Nuclear Information System (INIS)

    Xiao-Hua, Zhou

    2010-01-01

    We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys. Rev. E 53 4206] for the general shape equation of vesicle. Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained. Using the elliptic functions contained in mathematic, we find that this periodic shape has the minimal total energy for one period when the period–amplitude ratio β ≈ 1.477, and point out that it is a discontinuous deformation between plane and this periodic shape. Our results also are suitable for DNA and multi-walled carbon nanotubes (MWNTs). (cross-disciplinary physics and related areas of science and technology)

  12. Methods to isolate extracellular vesicles for diagnosis

    Science.gov (United States)

    Kang, Hyejin; Kim, Jiyoon; Park, Jaesung

    2017-12-01

    Extracellular vesicles (EVs) are small membrane-bound bodies that are released into extracellular space by diverse cells, and are found in body fluids like blood, urine and saliva. EVs contain RNA, DNA and proteins, which can be biomarkers for diagnosis. EVs can be obtained by minimally-invasive biopsy, so they are useful in disease diagnosis. High yield and purity contribute to precise diagnosis of disease, but damaged EVs and impurities can cause confu sed results. However, EV isolation methods have different yields and purities. Furthermore, the isolation method that is most suitable to maximize EV recovery efficiency depends on the experimental conditions. This review focuses on merits and demerits of several types of EV isolation methods, and provides examples of how to diagnose disease by exploiting information obtained by analysis of EVs.

  13. Seed priming with antioxidants improves sunflower seed germination and seedling growth under unfavorable germination conditions

    OpenAIRE

    DRAGANIC, Ivana; LEKIC, Slavoljub

    2012-01-01

    The results of studying the effects of sunflower seed priming with an aqueous solution of ascorbic acid (A), tocopherol (T), and glutathione (G) performed prior to accelerated ageing and a cold test are presented in this paper. Germination, the percentage of abnormal seedlings, and the lengths of both roots and shoots were monitored. The results showed that the cold test caused a drastic drop in germination, an adverse effect on the shoot length, an increase in the percentage of abnormal seed...

  14. Proteomics of Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles.

    Directory of Open Access Journals (Sweden)

    Thomas Kieselbach

    Full Text Available Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. Outer membrane vesicles (OMVs released by this species have been demonstrated to deliver effector proteins such as cytolethal distending toxin (CDT and leukotoxin (LtxA into human host cells and to act as triggers of innate immunity upon carriage of NOD1- and NOD2-active pathogen-associated molecular patterns (PAMPs. To improve our understanding of the pathogenicity-associated functions that A. actinomycetemcomitans exports via OMVs, we studied the proteome of density gradient-purified OMVs from a rough-colony type clinical isolate, strain 173 (serotype e using liquid chromatography-tandem mass spectrometry (LC-MS/MS. This analysis yielded the identification of 151 proteins, which were found in at least three out of four independent experiments. Data are available via ProteomeXchange with identifier PXD002509. Through this study, we not only confirmed the vesicle-associated release of LtxA, and the presence of proteins, which are known to act as immunoreactive antigens in the human host, but we also identified numerous additional putative virulence-related proteins in the A. actinomycetemcomitans OMV proteome. The known and putative functions of these proteins include immune evasion, drug targeting, and iron/nutrient acquisition. In summary, our findings are consistent with an OMV-associated proteome that exhibits several offensive and defensive functions, and they provide a comprehensive basis to further disclose roles of A. actinomycetemcomitans OMVs in periodontal and systemic disease.

  15. Influence of x-ray irradiation on the proliferative ability of the germinal layer cells of Echinococcus multilocularis

    International Nuclear Information System (INIS)

    Ohnishi, Kenji

    1986-01-01

    Influence of X-ray irradiation on the proliferative ability of the germinal layer cells of larval Echinococcus multilocularis was studied by using small sterile hydatids containing vesicles composed of a non-cellular laminated layer and a cellular germinal layer. The small sterile hydatids were irradiated by X-ray at dose levels of 5,000, 15,000, 25,000, 35,000, 45,000 or 55,000 R and implanted into the peritoneal cavity of Chinese hamsters. Fully developed hydatids were recognized in all cases irradiated at up to 35,000 R, when assessed 113 days after implantation. At 45,000 R, 2 out of 6 animals showed small, fully developed hydatids. No such hydatid was found in the other 4 animals nor in any of the animals implanted with hydatids irradiated at 55,000 R. No structural differences were observed between fully developed hydatids originating from the irradiated and non-irradiated small hydatids. These results indicate that the tolerance limit of the germinal layer cells is between 45,000 R and 55,000 R. (author)

  16. Phytotoxicity of glyphosate in the germination of and its effect on germinated seedlings

    Directory of Open Access Journals (Sweden)

    Subinoy Mondal

    2017-08-01

    Full Text Available The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds and seedlings. Physicochemical biomarkers were significantly changed by glyphosate exposure after 15 days. The germination of seedlings under control conditions (0 mg/L was 100% after 3 days of treatment but at 3 and 4 mg/L glyphosate, germination was reduced to 55 and 40%, respectively. Physiological parameters like root and shoot length decreased monotonically with increasing glyphosate concentration, at 14 days of observation. Average root and shoot length (n=30 in three replicates were reduced to 14.7 and 17.6%, respectively, at 4 mg/L glyphosate. Leaf chlorophyll content also decreased, with a similar trend to root and shoot length, but the protein content initially decreased and then increased with an increase in glyphosate concentration to 3 mg/L. The study suggests that glyphosate reduces the soluble sugar content significantly, by 21.6% (v/v. But internal sodium and potassium tissue concentrations were significantly altered by glyphosate exposure with increasing concentrations of glyphosate. Biochemical and physiological analysis also supports the inhibitory effect of glyphosate on seed germination and biochemical effects on seedlings.

  17. Seminal vesicle intrafraction motion analysed with cinematic magnetic resonance imaging

    International Nuclear Information System (INIS)

    Gill, Suki; Dang, Kim; Fox, Chris; Bressel, Mathias; Kron, Tomas; Bergen, Noelene; Ferris, Nick; Owen, Rebecca; Chander, Sarat; Tai, Keen Hun; Foroudi, Farshad

    2014-01-01

    This study analyses seminal vesicle displacement relative to the prostate and in relation to treatment time. A group of eleven patients undergoing prostate cancer radiotherapy were imaged with a continuous 3 T cine-MRI in the standard treatment setup position. Four images were recorded every 4 seconds for 15 minutes in the sagittal plane and every 6.5 seconds for 12 minutes in the coronal plane. The prostate gland and seminal vesicles were contoured on each MRI image. The coordinates of the centroid of the prostate and seminal vesicles on each image was analysed for displacement against time. Displacements between the 2.5 percentile and 97.5 percentile (i.e. the 2.5% trimmed range) for prostate and seminal vesicle centroid displacements were measured for 3, 5, 10 and 15 minutes time intervals in the anterior-posterior (AP), left-right (LR) and superior-inferior (SI) directions. Real time prostate and seminal vesicle displacement was compared for individual patients. The 2.5% trimmed range for 3, 5, 10 and 15 minutes for the seminal vesicle centroids in the SI direction measured 4.7 mm; 5.8 mm; 6.5 mm and 7.2 mm respectively. In the AP direction, it was 4.0 mm, 4.5 mm, 6.5 mm, and 7.0 mm. In the LR direction for 3, 5 and 10 minutes; for the left seminal vesicle, it was 2.7 mm, 2.8 mm, 3.4 mm and for the right seminal vesicle, it was 3.4 mm, 3.3 mm, and 3.4 mm. The correlation between the real-time prostate and seminal vesicle displacement varied substantially between patients indicating that the relationship between prostate displacement and seminal vesicles displacement is patient specific with the majority of the patients not having a strong relationship. Our study shows that seminal vesicle motion increases with treatment time, and that the prostate and seminal vesicle centroids do not move in unison in real time, and that an additional margin is required for independent seminal vesicle motion if treatment localisation is to the prostate

  18. Chemical inhibitors of viviparous germination in the fruit of watermelon.

    Science.gov (United States)

    Kobayashi, Yoshiki; Nabeta, Kensuke; Matsuura, Hideyuki

    2010-09-01

    It is well known that the seeds of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] have a high potential to germinate when the fruit has ripened. When removed from the mature fruit, the seeds can germinate under appropriate conditions. However, it is unclear why they cannot germinate in the flesh of the fruit. Here, we show that cis-ABA and its β-D-glucopyranosyl ester (ABA-β-GE) accumulate in the flesh of the fruit at levels high enough to inhibit seed germination. This result indicates the existence of chemical factors that inhibit viviparous seed germination of watermelon.

  19. Smoke-induced seed germination in California chaparral

    Science.gov (United States)

    Keeley, J.E.; Fotheringham, C.J.

    1998-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination in Caulanthus heterophyllus (Brassicaceae), Emmenanthe penduliflora (Hydrophyllaceae), Phacelia grandiflora (Hydrophyllaceae), and Silene multinervia (Caryophyllaceae). Three species, Dendromecon rigida (Papaveraceae), Dicentra chrysantha, and Trichostema lanatum (Lamiaceae), failed to germinate unless smoke treatment was coupled with prior treatment of 1 yr soil storage. Smoke-stimulated germination was found in 25 chaparral species, representing 11 families, none of which were families known for heat-shock-stimulated germination. Seeds of smoke-stimulated species have many analogous characteristics that separate them from most heat-shock-stimulated seeds, including: (1) outer seed coats that are highly textured, (2) a poorly developed outer cuticle, (3) absence of a dense palisade tissue in the seed coat, and (4) a subdermal membrane that is semipermeable, allowing water passage but blocking entry of large (molecular mass > 500) solutes. Tentative evidence suggests that permeability characteristics of this subdermal layer are altered by

  20. A model for quantification of temperature profiles via germination times

    DEFF Research Database (Denmark)

    Pipper, Christian Bressen; Adolf, Verena Isabelle; Jacobsen, Sven-Erik

    2013-01-01

    Current methodology to quantify temperature characteristics in germination of seeds is predominantly based on analysis of the time to reach a given germination fraction, that is, the quantiles in the distribution of the germination time of a seed. In practice interpolation between observed...... time and a specific type of accelerated failure time models is provided. As a consequence the observed number of germinated seeds at given monitoring times may be analysed directly by a grouped time-to-event model from which characteristics of the temperature profile may be identified and estimated...... germination fractions at given monitoring times is used to obtain the time to reach a given germination fraction. As a consequence the obtained value will be highly dependent on the actual monitoring scheme used in the experiment. In this paper a link between currently used quantile models for the germination...

  1. Vesicle fusion with bilayer lipid membrane controlled by electrostatic interaction

    Directory of Open Access Journals (Sweden)

    Azusa Oshima

    2017-09-01

    Full Text Available The fusion of proteoliposomes is a promising approach for incorporating membrane proteins in artificial lipid membranes. In this study, we employed an electrostatic interaction between vesicles and supported bilayer lipid membranes (s-BLMs to control the fusion process. We combined large unilamellar vesicles (LUVs containing anionic lipids, which we used instead of proteoliposomes, and s-BLMs containing cationic lipids to control electrostatic interaction. Anionic LUVs were never adsorbed or ruptured on the SiO2 substrate with a slight negative charge, and selectively fused with cationic s-BLMs. The LUVs can be fused effectively to the target position. Furthermore, as the vesicle fusion proceeds and some of the positive charges are neutralized, the attractive interaction weakens and finally the vesicle fusion saturates. In other words, we can control the number of LUVs fused with s-BLMs by controlling the concentration of the cationic lipids in the s-BLMs. The fluidity of the s-BLMs after vesicle fusion was confirmed to be sufficiently high. This indicates that the LUVs attached to the s-BLMs were almost completely fused, and there were few intermediate state vesicles in the fusion process. We could control the position and amount of vesicle fusion with the s-BLMs by employing an electrostatic interaction.

  2. Isolation of TRPV1 independent mechanisms of spontaneous and asynchronous glutamate release at primary afferent to NTS synapses.

    Directory of Open Access Journals (Sweden)

    Axel J. Fenwick

    2014-01-01

    Full Text Available Cranial visceral afferents contained within the solitary tract (ST contact second-order neurons in the nucleus of the solitary tract (NTS and release the excitatory amino acid glutamate via three distinct exocytosis pathways; synchronous, asynchronous, and spontaneous release. The presence of TRPV1 in the central terminals of a majority of ST afferents conveys activity-dependent asynchronous glutamate release and provides a temperature sensitive calcium conductance which largely determines the rate of spontaneous vesicle fusion. TRPV1 is present in unmyelinated C-fiber afferents and these facilitated forms of glutamate release may underlie the relative strength of C-fibers in activating autonomic reflex pathways. However, pharmacological blockade of TRPV1 signaling eliminates only ~50% of the asynchronous profile and attenuates the temperature sensitivity of spontaneous release indicating additional thermosensitive calcium influx pathways may exist which mediate these forms of vesicle release. In the present study we isolate the contribution of TRPV1 independent forms of glutamate release at ST-NTS synapses. We found ST afferent innervation at NTS neurons and synchronous vesicle release from TRPV1 KO mice was not different to control animals; however, only half of TRPV1 KO ST afferents completely lacked asynchronous glutamate release. Further, temperature driven spontaneous rates of vesicle release were not different from 33˚ - 37˚C between control and TRPV1 KO afferents. These findings suggest additional temperature dependent mechanisms controlling asynchronous and thermosensitive spontaneous release at physiological temperatures, possibly mediated by additional thermosensitive TRP channels in primary afferent terminals.

  3. Formation of Giant Protein Vesicles by a Lipid Cosolvent Method

    DEFF Research Database (Denmark)

    Hansen, Jesper S.; Vararattanavech, Ardcharaporn; Vissing, Thomas

    2011-01-01

    This paper describes a method to create giant protein vesicles (GPVs) of ≥10 μm by solvent‐driven fusion of large vesicles (0.1–0.2 μm) with reconstituted membrane proteins. We found that formation of GPVs proceeded from rotational mixing of protein‐reconstituted large unilamellar vesicles (LUVs)...... of spinach SoPIP2;1 and E. coli AqpZ aquaporins. Our findings show that hydrophobic interactions within the bilayer of formed GPVs are influenced not only by the solvent partitioning propensity, but also by lipid composition and membrane protein isoform....

  4. Generic sorting of raft lipids into secretory vesicles in yeast

    DEFF Research Database (Denmark)

    Surma, Michal A; Klose, Christian; Klemm, Robin W

    2011-01-01

    Previous work has showed that ergosterol and sphingolipids become sorted to secretory vesicles immunoisolated using a chimeric, artificial raft membrane protein as bait. In this study, we have extended this analysis to three populations of secretory vesicles isolated using natural yeast plasma...... a complete lipid overview of the yeast late secretory pathway. We could show that vesicles captured with different baits carry the same cargo and have almost identical lipid compositions; being highly enriched in ergosterol and sphingolipids. This finding indicates that lipid raft sorting is a generic...

  5. Spontaneously broken mass

    International Nuclear Information System (INIS)

    Endlich, Solomon; Nicolis, Alberto; Penco, Riccardo

    2015-01-01

    The Galilei group involves mass as a central charge. We show that the associated superselection rule is incompatible with the observed phenomenology of superfluid helium 4: this is recovered only under the assumption that mass is spontaneously broken. This remark is somewhat immaterial for the real world, where the correct space-time symmetries are encoded by the Poincaré group, which has no central charge. Yet it provides an explicit example of how superselection rules can be experimentally tested. We elaborate on what conditions must be met for our ideas to be generalizable to the relativistic case of the integer/half-integer angular momentum superselection rule.

  6. In vitro germination of desert rose varieties(

    Directory of Open Access Journals (Sweden)

    Tatiane Lemos Varella

    2015-08-01

    Full Text Available The drought stress resistance is a characteristic of the desert rose and its estimable beauty flowers, which gave it great relevance in the ornamental market. However, the desert rose production and germination is hampered by possible sterility of their male and female flowers and frequent problems in pollination, so the tissue culture is a promising alternative to the propagation of these plants. This study aimed to evaluate the effect of gibberellic acid on four commercial varieties of desert rose (Adenium obesum cultivated in vitro. The seeds of the varieties ‘Orange Pallet’, ‘Carnation violet’, ‘Diamond ring’ and ‘Vermiliont’ were sterilized and inoculated on Water + Agar (T0, medium MS (T1, ½ MS (T2, MS + 0.25 mg L-1 GA3 (T3, MS + 0.5 mg L-1 GA3 (T4, ½ MS + 0.25 mg L-1 GA3 (T5, ½ MS 0.5 mg L-1 GA3 (T6. The seeds germination of A. obesum was initiated on the fourth day of cultivation and on the tenth day was possible to observe the expansion of the cotyledons and leaf expansion with subsequent development of early secondary root. The ‘Orange pallet’ variety germinated 100% of seeds on water + agar and MS ½ + 0.5 mg L-1 of GA3. For ‘Diamond Ring’ and ‘Carnation violet’ the highest rate of germination occurred in treatments MS ½; 0.25 mg L-1 GA3; MS + 0.5 mg L-1 GA3 MS ½ + 0.5 mg L-1 GA3 averaging 80% and 70%, respectively. For ‘Vermiliont’ the best response was in MS and MS ½ + 0.5 mg L-1 GA3 ranging between 70-90% germinated embryos. It was registered different malformations in all treatments like absence of roots and apexes during seedling development. The concentrations of GA3 did not affect significantly the seed germination.

  7. Suicidal germination for parasitic weed control.

    Science.gov (United States)

    Zwanenburg, Binne; Mwakaboko, Alinanuswe S; Kannan, Chinnaswamy

    2016-11-01

    Parasitic weeds of the genera Striga and Orobanche spp. cause severe yield losses in agriculture, especially in developing countries and the Mediterranean. Seeds of these weeds germinate by a chemical signal exuded by the roots of host plants. The radicle thus produced attaches to the root of the host plant, which can then supply nutrients to the parasite. There is an urgent need to control these weeds to ensure better agricultural production. The naturally occurring chemical signals are strigolactones (SLs), e.g. strigol and orobanchol. One option to control these weeds involves the use of SLs as suicidal germination agents, where germination takes place in the absence of a host. Owing to the lack of nutrients, the germinated seeds will die. The structure of natural SLs is too complex to allow multigram synthesis. Therefore, SL analogues are developed for this purpose. Examples are GR24 and Nijmegen-1. In this paper, the SL analogues Nijmegen-1 and Nijmegen-1 Me were applied in the field as suicidal germination agents. Both SL analogues were formulated using an appropriate EC-approved emulsifier (polyoxyethylene sorbitol hexaoleate) and applied to tobacco (Nicotiana tabacum L.) fields infested by Orobanche ramosa L. (hemp broomrape), following a strict protocol. Four out of 12 trials showed a reduction in broomrape of ≥95%, two trials were negative, two showed a moderate result, one was unclear and in three cases there was no Orobanche problem in the year of the trials. The trial plots were ca 2000 m 2 ; half of that area was treated with stimulant emulsion, the other half was not treated. The optimal amount of stimulant was 6.25 g ha -1 . A preconditioning prior to the treatment was a prerequisite for a successful trial. In conclusion, the suicidal germination approach to reducing O. ramosa in tobacco fields using formulated SL analogues was successful. Two other options for weed control are discussed: deactivation of stimulants prior to action and

  8. EFFECTS OF PRE-GERMINATION TREATMENTS AND STORAGE ON GERMINATION OF Astronium fraxinifolium SCHOTT (ANACARDIACEAE DIASPORES

    Directory of Open Access Journals (Sweden)

    Lílian de Lima Braga

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814577The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores; diaspores immersed in water at room temperature (25º C for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000 for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar and two environmental conditions (cold chamber and room conditions, resulting in four treatments. The germination tests were performed for zero (control and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%, control (97.0 ± 4.83%, water at room temperature (96.0 ± 6.99% and water at 70º C (83.0 ± 29.08% treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.

  9. Supramolecular "Big Bang" in a Single-Ionic Surfactant/Water System Driven by Electrostatic Repulsion: From Vesicles to Micelles.

    Science.gov (United States)

    Leclercq, Loïc; Bauduin, Pierre; Nardello-Rataj, Véronique

    2017-04-11

    In aqueous solution, dimethyldi-n-octylammonium chloride, [DiC 8 ][Cl], spontaneously forms dimers at low concentrations (1-10 mM) to decrease the strength of the hydrophobic-water contact. Dimers represent ideal building blocks for the abrupt edification of vesicles at 10 mM. These vesicles are fully characterized by dynamic and static light scattering, self-diffusion nuclear magnetic resonance, and freeze-fracture transmission electron microscopy. An increase in concentration leads to electrostatic repulsion between vesicles that explode into small micelles at 30 mM. These transitions are detected by means of surface tension, conductivity, and solubility of hydrophobic solutes as well as by isothermal titration microcalorimetry. These unusual supramolecular transitions emerge from the surfactant chemical structure that combines two contradictory features: (i) the double-chain structure tending to form low planar aggregates with low water solubility and (ii) the relatively short chains giving high hydrophilicity. The well-balanced hydrophilic-hydrophobic character of [DiC 8 ][Cl] is then believed to be at the origin of the unusual supramolecular sequence offering new opportunities for drug delivery systems.

  10. Glioblastoma extracellular vesicles: reservoirs of potential biomarkers

    Directory of Open Access Journals (Sweden)

    Redzic JS

    2014-02-01

    Full Text Available Jasmina S Redzic,1 Timothy H Ung,2 Michael W Graner2 1Skaggs School of Pharmacy and Pharmaceutical Sciences, 2Department of Neurosurgery, School of Medicine, University of Colorado Denver, Aurora, CO, USA Abstract: Glioblastoma multiforme (GBM is the most frequent and most devastating of the primary central nervous system tumors, with few patients living beyond 2 years postdiagnosis. The damage caused by the disease and our treatments for the patients often leave them physically and cognitively debilitated. Generally, GBMs appear after very short clinical histories and are discovered by imaging (using magnetic resonance imaging [MRI], and the diagnosis is validated by pathology, following surgical resection. The treatment response and diagnosis of tumor recurrence are also tracked by MRI, but there are numerous problems encountered with these monitoring modalities, such as ambiguous interpretation and forms of pseudoprogression. Diagnostic, prognostic, and predictive biomarkers would be an immense boon in following treatment schemes and in determining recurrence, which often requires an invasive intracranial biopsy to verify imaging data. Extracellular vesicles (EVs are stable, membrane-enclosed, virus-sized particles released from either the cell surface or from endosomal pathways that lead to the systemic release of EVs into accessible biofluids, such as serum/plasma, urine, cerebrospinal fluid, and saliva. EVs carry a wide variety of proteins, nucleic acids, lipids, and other metabolites, with many common features but with enough individuality to be able to identify the cell of origin of the vesicles. These components, if properly interrogated, could allow for the identification of tumor-derived EVs in biofluids, indicating tumor progression, relapse, or treatment failure. That knowledge would allow clinicians to continue with treatment regimens that were actually effective or to change course if the therapies were failing. Here, we review

  11. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  12. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Cardwell, C.; Cox, I.; Baldey, A.

    2002-01-01

    Full text: A 49-year old female presented with severe postural headache with no history of trauma. A Computed Tomography (CT) study of the brain demonstrated abnormal meningeal enhancement raising the possibility of leptomeningeal metastases. The patient was then referred to Magnetic Resonance Imaging (MRI) which demonstrated diffuse smooth dural enhancement with ancillary findings characteristic of spontaneous intracranial hypotension. The patient was then referred to Nuclear Medicine to confirm the diagnosis and localise the presumed leak 400MBq of 99mTc DTPA was injected via lumbar puncture into the L3-L4 subarachnoid space Posterior images of the spine were taken with a GE XRT single head gamma camera at 1 and 4 hours post administration of radionuclide. Images demonstrated abnormal early arrival of radionuclide in the kidneys and bladder at 1 hour and abnormal leak of tracer was demonstrate at the level of the first thoracic vertebra on the right side at 4 hours. This confirmed CSF leak at this level. Consequently the patient underwent a blood patch and her symptoms resolved. Spontaneous Intracranial Hypotension is a syndrome often unrecognised presenting with symptoms including severe postural headache neck stiffness nausea vomiting tinnitus and vertigo. The diagnosis is frequently suspected from findings on MRI, but Nuclear Medicine CSF imaging provides a readily available and cost effective method for confirming the diagnosis, and for making the diagnosis in patients who are unsuitable for or do not have access to MRI. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  13. Spontaneous intracranial hypotension

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, C; Cox, I; Baldey, A [St. F.X. Cabrini Hospital, VIC (Australia). Departments of Nuclear Medicine and Magnetic Resonance Imaging

    2002-07-01

    Full text: A 49-year old female presented with severe postural headache with no history of trauma. A Computed Tomography (CT) study of the brain demonstrated abnormal meningeal enhancement raising the possibility of leptomeningeal metastases. The patient was then referred to Magnetic Resonance Imaging (MRI) which demonstrated diffuse smooth dural enhancement with ancillary findings characteristic of spontaneous intracranial hypotension. The patient was then referred to Nuclear Medicine to confirm the diagnosis and localise the presumed leak 400MBq of 99mTc DTPA was injected via lumbar puncture into the L3-L4 subarachnoid space Posterior images of the spine were taken with a GE XRT single head gamma camera at 1 and 4 hours post administration of radionuclide. Images demonstrated abnormal early arrival of radionuclide in the kidneys and bladder at 1 hour and abnormal leak of tracer was demonstrate at the level of the first thoracic vertebra on the right side at 4 hours. This confirmed CSF leak at this level. Consequently the patient underwent a blood patch and her symptoms resolved. Spontaneous Intracranial Hypotension is a syndrome often unrecognised presenting with symptoms including severe postural headache neck stiffness nausea vomiting tinnitus and vertigo. The diagnosis is frequently suspected from findings on MRI, but Nuclear Medicine CSF imaging provides a readily available and cost effective method for confirming the diagnosis, and for making the diagnosis in patients who are unsuitable for or do not have access to MRI. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc.

  14. Polyamine biosynthesis during germination of yeast ascospores.

    Science.gov (United States)

    Brawley, J V; Ferro, A J

    1979-01-01

    The role of the diamine putrescine during germination and outgrowth of ascospores of Saccharomyces cerevisiae was examined. Ornithine decarboxylase activity increased and declined rapidly during germination and outgrowth; peak activity was attained after the cells had proceeded through the G1 interval of the cell cycle, whereas minimal activity was present at the completion of the first cell division. alpha-Methylornithine inhibited both ornithine decarboxylase activity and the in vivo accumulation of putrescine. In the presence of alpha-methylornithireak dormancy and proceed through one cell division. Subsequent cellular growth, however, was retarded but not completely inhibited. The supplementation of Methylglyoxal bis(guanylhydrazone) to sporulation medium greatly inhibited this sexual process. These data suggest that the synthesis of putrescine is not required for the breaking of spore dormancy, but that polyamine biosynthesis may be essential for meiosis and sporulation. PMID:387744

  15. Germination and storage of caranda seeds (Copernicia alba

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    2012-12-01

    Full Text Available Caranda is a Brazilian native palm tree, belonging to Arecaceae family and occurring, predominan,t in the Brazilian Swampland. This work studied the germination and the caranda seeds storage behavior. The germination study was carried out in the temperatures of 25ºC and 30ºC in constant white light and the alternate temperature of 20/30ºC with 10 hours of darkness for the lowest temperature and 14 hours of light for the highest temperature, using paper and paper roll as substratum. At the end of test, the germination percentage, germination speed index, germination medium time and the primary root length were evaluated. After the seeds improvement, it was obtained two sub-samples destined for 30 days storage in two invironments: cold and dry chamber (16ºC/55% UR and freezer (-18ºC. The following tests, water content, germination, germination medium time and primary root length were evaluated. The caranda seeds germination in paper roll and on paper is favored by the temperature of 20/30ºC in paper roll and on paper and paper roll on 30ºC. The freezing and cold camera storage during 30 days are efficient to reduce the germination medium time of caranda seeds and to keep the germination percentage.

  16. In vitro germination of desert rose varieties(

    OpenAIRE

    Tatiane Lemos Varella; Gizelly Mendes Silva; Kaliane Zaira Camacho Maximiliano da Cruz; Andréia Izabel Mikovski; Josué Ribeiro da Silva Nunes; Ilio Fealho Carvalho; Maurecilne Lemes Silva

    2015-01-01

    The drought stress resistance is a characteristic of the desert rose and its estimable beauty flowers, which gave it great relevance in the ornamental market. However, the desert rose production and germination is hampered by possible sterility of their male and female flowers and frequent problems in pollination, so the tissue culture is a promising alternative to the propagation of these plants. This study aimed to evaluate the effect of gibberellic acid on four commercial varieties of dese...

  17. Improved Methods of Producing and Administering Extracellular Vesicles | Poster

    Science.gov (United States)

    An efficient method of producing purified extracellular vesicles (EVs), in conjunction with a method that blocks liver macrophages from clearing EVs from the body, has produced promising results for the use of EVs in cancer therapy.

  18. EVpedia : a community web portal for extracellular vesicles research

    NARCIS (Netherlands)

    Kim, Dae-Kyum; Lee, Jaewook; Kim, Sae Rom; Choi, Dong-Sic; Yoon, Yae Jin; Kim, Ji Hyun; Go, Gyeongyun; Nhung, Dinh; Hong, Kahye; Jang, Su Chul; Kim, Si-Hyun; Park, Kyong-Su; Kim, Oh Youn; Park, Hyun Taek; Seo, Ji Hye; Aikawa, Elena; Baj-Krzyworzeka, Monika; van Balkom, Bas W M; Belting, Mattias; Blanc, Lionel; Bond, Vincent; Bongiovanni, Antonella; Borràs, Francesc E; Buée, Luc; Buzás, Edit I; Cheng, Lesley; Clayton, Aled; Cocucci, Emanuele; Dela Cruz, Charles S; Desiderio, Dominic M; Di Vizio, Dolores; Ekström, Karin; Falcon-Perez, Juan M; Gardiner, Chris; Giebel, Bernd; Greening, David W; Gross, Julia Christina; Gupta, Dwijendra; Hendrix, An; Hill, Andrew F; Hill, Michelle M; Nolte-'t Hoen, Esther; Hwang, Do Won; Inal, Jameel; Jagannadham, Medicharla V; Jayachandran, Muthuvel; Jee, Young-Koo; Jørgensen, Malene; Kim, Kwang Pyo; Kim, Yoon-Keun; Kislinger, Thomas; Lässer, Cecilia; Lee, Dong Soo; Lee, Hakmo; van Leeuwen, Johannes; Lener, Thomas; Liu, Ming-Lin; Lötvall, Jan; Marcilla, Antonio; Mathivanan, Suresh; Möller, Andreas; Morhayim, Jess; Mullier, François; Nazarenko, Irina; Nieuwland, Rienk; Nunes, Diana N; Pang, Ken; Park, Jaesung; Patel, Tushar; Pocsfalvi, Gabriella; Del Portillo, Hernando; Putz, Ulrich; Ramirez, Marcel I; Rodrigues, Marcio L; Roh, Tae-Young; Royo, Felix; Sahoo, Susmita; Schiffelers, Raymond|info:eu-repo/dai/nl/212909509; Sharma, Shivani; Siljander, Pia; Simpson, Richard J; Soekmadji, Carolina; Stahl, Philip; Stensballe, Allan; Stępień, Ewa; Tahara, Hidetoshi; Trummer, Arne; Valadi, Hadi; Vella, Laura J; Wai, Sun Nyunt; Witwer, Kenneth; Yáñez-Mó, María; Youn, Hyewon; Zeidler, Reinhard; Gho, Yong Song; Nolte - t Hoen, Esther|info:eu-repo/dai/nl/261632175

    2014-01-01

    MOTIVATION: Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. RESULTS: We

  19. EVpedia: a community web portal for extracellular vesicles research

    NARCIS (Netherlands)

    Kim, Dae-Kyum; Lee, Jaewook; Kim, Sae Rom; Choi, Dong-Sic; Yoon, Yae Jin; Kim, Ji Hyun; Go, Gyeongyun; Nhung, Dinh; Hong, Kahye; Jang, Su Chul; Kim, Si-Hyun; Park, Kyong-Su; Kim, Oh Youn; Park, Hyun Taek; Seo, Ji Hye; Aikawa, Elena; Baj-Krzyworzeka, Monika; van Balkom, Bas W. M.; Belting, Mattias; Blanc, Lionel; Bond, Vincent; Bongiovanni, Antonella; Borràs, Francesc E.; Buée, Luc; Buzás, Edit I.; Cheng, Lesley; Clayton, Aled; Cocucci, Emanuele; Dela Cruz, Charles S.; Desiderio, Dominic M.; Di Vizio, Dolores; Ekström, Karin; Falcon-Perez, Juan M.; Gardiner, Chris; Giebel, Bernd; Greening, David W.; Gross, Julia Christina; Gupta, Dwijendra; Hendrix, An; Hill, Andrew F.; Hill, Michelle M.; Nolte-'t Hoen, Esther; Hwang, Do Won; Inal, Jameel; Jagannadham, Medicharla V.; Jayachandran, Muthuvel; Jee, Young-Koo; Jørgensen, Malene; Kim, Kwang Pyo; Kim, Yoon-Keun; Kislinger, Thomas; Lässer, Cecilia; Lee, Dong Soo; Lee, Hakmo; van Leeuwen, Johannes; Lener, Thomas; Liu, Ming-Lin; Lötvall, Jan; Marcilla, Antonio; Mathivanan, Suresh; Möller, Andreas; Morhayim, Jess; Mullier, François; Nazarenko, Irina; Nieuwland, Rienk; Nunes, Diana N.; Pang, Ken; Park, Jaesung; Patel, Tushar; Pocsfalvi, Gabriella; del Portillo, Hernando; Putz, Ulrich; Ramirez, Marcel I.; Rodrigues, Marcio L.; Roh, Tae-Young; Royo, Felix; Sahoo, Susmita; Schiffelers, Raymond; Sharma, Shivani; Siljander, Pia; Simpson, Richard J.; Soekmadji, Carolina; Stahl, Philip; Stensballe, Allan; Stępień, Ewa; Tahara, Hidetoshi; Trummer, Arne; Valadi, Hadi; Vella, Laura J.; Wai, Sun Nyunt; Witwer, Kenneth; Yáñez-Mó, María; Youn, Hyewon; Zeidler, Reinhard; Gho, Yong Song

    2015-01-01

    Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. We present an improved

  20. Biological properties of extracellular vesicles and their physiological functions

    NARCIS (Netherlands)

    Yáñez-Mó, María; Siljander, Pia R-M; Andreu, Zoraida; Zavec, Apolonija Bedina; Borràs, Francesc E; Buzas, Edit I; Buzas, Krisztina; Casal, Enriqueta; Cappello, Francesco; Carvalho, Joana; Colás, Eva; Cordeiro-da Silva, Anabela; Fais, Stefano; Falcon-Perez, Juan M; Ghobrial, Irene M; Giebel, Bernd; Gimona, Mario; Graner, Michael; Gursel, Ihsan; Gursel, Mayda; Heegaard, Niels H H; Hendrix, An; Kierulf, Peter; Kokubun, Katsutoshi; Kosanovic, Maja; Kralj-Iglic, Veronika; Krämer-Albers, Eva-Maria; Laitinen, Saara; Lässer, Cecilia; Lener, Thomas; Ligeti, Erzsébet; Linē, Aija; Lipps, Georg; Llorente, Alicia; Lötvall, Jan; Manček-Keber, Mateja; Marcilla, Antonio; Mittelbrunn, Maria; Nazarenko, Irina; Nolte-'t Hoen, Esther N M; Nyman, Tuula A; O'Driscoll, Lorraine; Olivan, Mireia; Oliveira, Carla; Pállinger, Éva; Del Portillo, Hernando A; Reventós, Jaume; Rigau, Marina; Rohde, Eva; Sammar, Marei; Sánchez-Madrid, Francisco; Santarém, N; Schallmoser, Katharina; Ostenfeld, Marie Stampe; Stoorvogel, Willem|info:eu-repo/dai/nl/074352385; Stukelj, Roman; Van der Grein, Susanne G|info:eu-repo/dai/nl/412755211; Vasconcelos, M Helena; Wauben, Marca H M|info:eu-repo/dai/nl/112675735; De Wever, Olivier

    2015-01-01

    In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological

  1. Packing states of multilamellar vesicles in a nonionic surfactant system

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.

    2001-01-01

    -alpha(*) phase using the noninvasive small-angle neutron scattering (SANS) technique, one while heating and the other while cooling the sample. Data from the heating and cooling cycles were used to demonstrate reversibility of the system. Three states of packing can be identified from the scattering profiles......Lyotropic lamellar phases under shear flow have been shown to form multilamellar vesicles (MLVs), an onion-like structure. The size of the vesicles is governed by the shear imposed on the sample. Previously, we studied the structural transformation from multilamellar vesicles to lamellae to sponge...... under shear. Here, we focused only in the MLV region, L-alpha(*), of a temperature sensitive surfactant system (C12E4-water) to investigate the packing of multilamellar vesicles as a function of temperature under constant shear. Two sets of temperature scan experiments were performed in the L...

  2. Biogenesis and function of Porphyromonas gingivalis outer membrane vesicles

    Science.gov (United States)

    Xie, H

    2015-01-01

    Porphyromonas gingivalis is one of the keystone pathogens associated with chronic periodontitis. All P. gingivalis strains examined thus far produce outer membrane vesicles. Recent studies have found that vesicles possess some well-known virulence factors of P. gingivalis such as adhesins, toxins and proteolytic enzymes. Carrying most of the characteristic features of their parent P. gingivalis cells, vesicles communicate with host cells and other members of microbial biofilms, resulting in the transmission of virulence factors into these host cells and the formation of pathogenic bacteria-dominated microbial communities. An in-depth understanding of both the nature and role of vesicles in the pathogenicity of P. gingivalis is both important and timely, particularly when speaking of periodontitis and its related systemic effects. PMID:26343879

  3. Integral equation methods for vesicle electrohydrodynamics in three dimensions

    Science.gov (United States)

    Veerapaneni, Shravan

    2016-12-01

    In this paper, we develop a new boundary integral equation formulation that describes the coupled electro- and hydro-dynamics of a vesicle suspended in a viscous fluid and subjected to external flow and electric fields. The dynamics of the vesicle are characterized by a competition between the elastic, electric and viscous forces on its membrane. The classical Taylor-Melcher leaky-dielectric model is employed for the electric response of the vesicle and the Helfrich energy model combined with local inextensibility is employed for its elastic response. The coupled governing equations for the vesicle position and its transmembrane electric potential are solved using a numerical method that is spectrally accurate in space and first-order in time. The method uses a semi-implicit time-stepping scheme to overcome the numerical stiffness associated with the governing equations.

  4. Extracellular vesicles provide a means for tissue crosstalk during exercise

    DEFF Research Database (Denmark)

    Whitham, Martin; Parker, Benjamin L; Friedrichsen, Martin

    2018-01-01

    Exercise stimulates the release of molecules into the circulation, supporting the concept that inter-tissue signaling proteins are important mediators of adaptations to exercise. Recognizing that many circulating proteins are packaged in extracellular vesicles (EVs), we employed quantitative prot...

  5. EVpedia : A community web portal for extracellular vesicles research

    NARCIS (Netherlands)

    Kim, Dae Kyum; Lee, Jaewook; Kim, Sae Rom; Choi, Dong Sic; Yoon, Yae Jin; Kim, Ji Hyun; Go, Gyeongyun; Nhung, Dinh; Hong, Kahye; Jang, Su Chul; Kim, Si Hyun; Park, Kyong Su; Kim, Oh Youn; Park, Hyun Taek; Seo, Ji Hye; Aikawa, Elena; Baj-Krzyworzeka, Monika; Van Balkom, Bas W M; Belting, Mattias; Blanc, Lionel; Bond, Vincent; Bongiovanni, Antonella; Borràs, Francesc E.; Buée, Luc; Buzás, Edit I.; Cheng, Lesley; Clayton, Aled; Cocucci, Emanuele; Dela Cruz, Charles S.; Desiderio, Dominic M.; Di Vizio, Dolores; Ekström, Karin; Falcon-Perez, Juan M.; Gardiner, Chris; Giebel, Bernd; Greening, David W.; Christina Gross, Julia; Gupta, Dwijendra; Hendrix, An; Hill, Andrew F.; Hill, Michelle M.; Nolte-'T Hoen, Esther; Hwang, Do Won; Inal, Jameel; Jagannadham, Medicharla V.; Jayachandran, Muthuvel; Jee, Young Koo; Jørgensen, Malene; Kim, Kwang Pyo; Kim, Yoon Keun; Kislinger, Thomas; Lässer, Cecilia; Lee, Dong Soo; Lee, Hakmo; Van Leeuwen, Johannes; Lener, Thomas; Liu, Ming Lin; Lötvall, Jan; Marcilla, Antonio; Mathivanan, Suresh; Möller, Andreas; Morhayim, Jess; Mullier, Francois; Nazarenko, Irina; Nieuwland, Rienk; Nunes, Diana N.; Pang, Ken; Park, Jaesung; Patel, Tushar; Pocsfalvi, Gabriella; Del Portillo, Hernando; Putz, Ulrich; Ramirez, Marcel I.; Rodrigues, Marcio L.; Roh, Tae Young; Royo, Felix; Sahoo, Susmita; Schiffelers, Raymond; Sharma, Shivani; Siljander, Pia; Simpson, Richard J.; Soekmadji, Carolina; Stahl, Philip; Stensballe, Allan; Stepień, Ewa; Tahara, Hidetoshi; Trummer, Arne; Valadi, Hadi; Vella, Laura J.; Wai, Sun Nyunt; Witwer, Kenneth; Yánez-Mó, Maria; Youn, Hyewon; Zeidler, Reinhard; Gho, Yong Song

    2015-01-01

    Motivation: Extracellular vesicles (EVs) are spherical bilayered proteolipids, harboring various bioactive molecules. Due to the complexity of the vesicular nomenclatures and components, online searches for EV-related publications and vesicular components are currently challenging. Results: We

  6. Understanding crumpling lipid vesicles at the gel phase transition

    Science.gov (United States)

    Hirst, Linda; Ossowski, Adam; Fraser, Matthew

    2011-03-01

    Wrinkling and crumpling transitions in different membrane types have been studied extensively in recent years both theoretically and computationally. There has also been very interesting recent work on defects in liquid crystalline shells. Lipid bilayer vesicles, widely used in biophysical research can be considered as a single layer smectic shell in the liquid crystalline phase. On cooling the lipid vesicle a transition to the gel phase may take place in which the lipid chains tilt and assume a more ordered packing arrangement. We observe large scale morphological changes in vesicles close to this transition point using fluorescence microscopy and investigate the possible mechanisms for this transition. Confocal microscopy is used to map 3D vesicle shape and crumpling length-scales. We also employ the molecular tilt sensitive dye, Laurdan to investigate the role of tilt domain formation on macroscopic structure. Funded by NSF CAREER award (DMR - BMAT #0852791).

  7. ABC triblock copolymer vesicles with mesh-like morphology.

    Science.gov (United States)

    Zhao, Wei; Chen, Dian; Hu, Yunxia; Grason, Gregory M; Russell, Thomas P

    2011-01-25

    Polymer vesicles made from poly(isoprene-b-styrene-b-2-vinyl pyridine) (PI-b-PS-b-P2VP) triblock copolymer confined within the nanopores of an anodic aluminum oxide (AAO) membrane are studied. It was found that these vesicles have well-defined, nanoscopic size, and complex microphase-separated hydrophobic membranes, comprised of the PS and PI blocks, while the coronas are formed by the P2VP block. Vesicle formation was tracked using both transmission and scanning electron microscopy. A mesh-like morphology formed in the membrane at a well-defined composition of the three blocks that can be tuned by changing the copolymer composition. The nanoscale confinement, copolymer composition, and subtle molecular interactions contribute to the generation of these vesicles with such unusual morphologies.

  8. Plasma membrane aquaporins mediates vesicle stability in broccoli.

    Directory of Open Access Journals (Sweden)

    Maria Del Carmen Martínez-Ballesta

    Full Text Available The use of in vitro membrane vesicles is attractive because of possible applications in therapies. Here we aimed to compare the stability and functionality of plasma membrane vesicles extracted from control and salt-treated broccoli. The impact of the amount of aquaporins was related to plasma membrane osmotic water permeability and the stability of protein secondary structure. Here, we describe for first time an increase in plant aquaporins acetylation under high salinity. Higher osmotic water permeability in NaCl vesicles has been related to higher acetylation, upregulation of aquaporins, and a more stable environment to thermal denaturation. Based on our findings, we propose that aquaporins play an important role in vesicle stability.

  9. Assembly of cells and vesicles for organ engineering

    International Nuclear Information System (INIS)

    Taguchi, Tetsushi

    2011-01-01

    The development of materials and technologies for the assembly of cells and/or vesicles is a key for the next generation of tissue engineering. Since the introduction of the tissue engineering concept in 1993, various types of scaffolds have been developed for the regeneration of connective tissues in vitro and in vivo. Cartilage, bone and skin have been successfully regenerated in vitro, and these regenerated tissues have been applied clinically. However, organs such as the liver and pancreas constitute numerous cell types, contain small amounts of extracellular matrix, and are highly vascularized. Therefore, organ engineering will require the assembly of cells and/or vesicles. In particular, adhesion between cells/vesicles will be required for regeneration of organs in vitro. This review introduces and discusses the key technologies and materials for the assembly of cells/vesicles for organ regeneration. (topical review)

  10. Towards traceable size determination of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Zoltán Varga

    2014-02-01

    Full Text Available Background: Extracellular vesicles (EVs have clinical importance due to their roles in a wide range of biological processes. The detection and characterization of EVs are challenging because of their small size, low refractive index, and heterogeneity. Methods: In this manuscript, the size distribution of an erythrocyte-derived EV sample is determined using state-of-the-art techniques such as nanoparticle tracking analysis, resistive pulse sensing, and electron microscopy, and novel techniques in the field, such as small-angle X-ray scattering (SAXS and size exclusion chromatography coupled with dynamic light scattering detection. Results: The mode values of the size distributions of the studied erythrocyte EVs reported by the different methods show only small deviations around 130 nm, but there are differences in the widths of the size distributions. Conclusion: SAXS is a promising technique with respect to traceability, as this technique was already applied for traceable size determination of solid nanoparticles in suspension. To reach the traceable measurement of EVs, monodisperse and highly concentrated samples are required.

  11. Anaesthetics stop diverse plant organ movements, affect endocytic vesicle recycling and ROS homeostasis, and block action potentials in Venus flytraps.

    Science.gov (United States)

    Yokawa, K; Kagenishi, T; Pavlovic, A; Gall, S; Weiland, M; Mancuso, S; Baluška, F

    2017-12-11

    Anaesthesia for medical purposes was introduced in the 19th century. However, the physiological mode of anaesthetic drug actions on the nervous system remains unclear. One of the remaining questions is how these different compounds, with no structural similarities and even chemically inert elements such as the noble gas xenon, act as anaesthetic agents inducing loss of consciousness. The main goal here was to determine if anaesthetics affect the same or similar processes in plants as in animals and humans. A single-lens reflex camera was used to follow organ movements in plants before, during and after recovery from exposure to diverse anaesthetics. Confocal microscopy was used to analyse endocytic vesicle trafficking. Electrical signals were recorded using a surface AgCl electrode. Mimosa leaves, pea tendrils, Venus flytraps and sundew traps all lost both their autonomous and touch-induced movements after exposure to anaesthetics. In Venus flytrap, this was shown to be due to the loss of action potentials under diethyl ether anaesthesia. The same concentration of diethyl ether immobilized pea tendrils. Anaesthetics also impeded seed germination and chlorophyll accumulation in cress seedlings. Endocytic vesicle recycling and reactive oxygen species (ROS) balance, as observed in intact Arabidopsis root apex cells, were also affected by all anaesthetics tested. Plants are sensitive to several anaesthetics that have no structural similarities. As in animals and humans, anaesthetics used at appropriate concentrations block action potentials and immobilize organs via effects on action potentials, endocytic vesicle recycling and ROS homeostasis. Plants emerge as ideal model objects to study general questions related to anaesthesia, as well as to serve as a suitable test system for human anaesthesia. © The Authors 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Extracellular vesicles in Alzheimer's disease: friends or foes? Focus on aβ-vesicle interaction.

    Science.gov (United States)

    Joshi, Pooja; Benussi, Luisa; Furlan, Roberto; Ghidoni, Roberta; Verderio, Claudia

    2015-03-03

    The intercellular transfer of amyloid-β (Aβ) and tau proteins has received increasing attention in Alzheimer's disease (AD). Among other transfer modes, Aβ and tau dissemination has been suggested to occur through release of Extracellular Vesicles (EVs), which may facilitate delivery of pathogenic proteins over large distances. Recent evidence indicates that EVs carry on their surface, specific molecules which bind to extracellular Aβ, opening the possibility that EVs may also influence Aβ assembly and synaptotoxicity. In this review we focus on studies which investigated the impact of EVs in Aβ-mediated neurodegeneration and showed either detrimental or protective role for EVs in the pathology.

  13. CAPS Activity in Priming Vesicle Exocytosis Requires CK2 Phosphorylation*

    OpenAIRE

    Nojiri, Mari; Loyet, Kelly M.; Klenchin, Vadim A.; Kabachinski, Gregory; Martin, Thomas F. J.

    2009-01-01

    CAPS (Ca2+-dependent activator protein for secretion) functions in priming Ca2+-dependent vesicle exocytosis, but the regulation of CAPS activity has not been characterized. Here we show that phosphorylation by protein kinase CK2 is required for CAPS activity. Dephosphorylation eliminated CAPS activity in reconstituting Ca2+-dependent vesicle exocytosis in permeable and intact PC12 cells. Ser-5, -6, and -7 and Ser-1281 were identified by mass spectrometry as the major phosphorylation sites in...

  14. Cystadenoma of the seminal vesicle. A case report

    DEFF Research Database (Denmark)

    Lundhus, E; Bundgaard, N; Sørensen, Flemming Brandt

    1984-01-01

    Cystadenomas of the seminal vesicle are extremely rare benign tumours, which only have been reported seven times earlier in the literature. The first Danish case is reported with discussion of symptomatology, pathology and treatment.......Cystadenomas of the seminal vesicle are extremely rare benign tumours, which only have been reported seven times earlier in the literature. The first Danish case is reported with discussion of symptomatology, pathology and treatment....

  15. Interaction and rheology of vesicle suspensions in confined shear flow

    Science.gov (United States)

    Shen, Zaiyi; Farutin, Alexander; Thiébaud, Marine; Misbah, Chaouqi

    2017-10-01

    Dynamics and rheology of a confined suspension of vesicles (a model for red blood cells) are studied numerically in two dimensions by using an immersed boundary lattice Boltzmann method. We pay particular attention to the link between the spatiotemporal organization and the rheology of the suspension. Besides confinement, we analyze the effect of concentration of the suspension, ϕ (defined as the area fraction occupied by the vesicles in the simulation domain), as well as the viscosity contrast λ (defined as the ratio between the viscosity of the fluid inside the vesicles, ηint, and that of the suspending fluid, ηext). The hydrodynamic interaction between two vesicles is shown to play a key role in determining the spatial organization. For λ =1 , the pair of vesicles settles into an equilibrium state with constant interdistance, which is regulated by the confinement. The equilibrium interdistance increases with the gap between walls, following a linear relationship. However, no stable equilibrium interdistance between two tumbling vesicles is observed for λ =10 . A quite ordered suspension is observed concomitant with the existence of an equilibrium interdistance between a vesicle pair. However, a disordered suspension prevails when no pair equilibrium interdistance exists, as occurs for tumbling vesicles. We then analyze the rheology, focusing on the effective viscosity, denoted as η , as well as on normalized viscosity, defined as [η ] =(η -ηext) /(ηextϕ ) . Ordering of the suspension is accompanied by a nonmonotonic behavior of [η ] with ϕ , while η exhibits plateaus. The nonmonotonic behavior of [η ] is suppressed when a disordered pattern prevails.

  16. Extracellular Membrane Vesicles and Phytopathogenicity of Acholeplasma laidlawii PG8

    Directory of Open Access Journals (Sweden)

    Vladislav M. Chernov

    2012-01-01

    Full Text Available For the first time, the phytopathogenicity of extracellular vesicles of Acholeplasma laidlawii PG8 (a ubiquitous mycoplasma that is one of the five common species of cell culture contaminants and is a causative agent for phytomycoplasmoses in Oryza sativa L. plants was studied. Data on the ability of extracellular vesicles of Acholeplasma laidlawii PG8 to penetrate from the nutrient medium into overground parts of Oryza sativa L. through the root system and to cause alterations in ultrastructural organization of the plants were presented. As a result of the analysis of ultrathin leaf sections of plants grown in medium with A. laidlawii PG8 vesicles, we detected significant changes in tissue ultrastructure characteristic to oxidative stress in plants as well as their cultivation along with bacterial cells. The presence of nucleotide sequences of some mycoplasma genes within extracellular vesicles of Acholeplasma laidlawii PG8 allowed a possibility to use PCR (with the following sequencing to perform differential detection of cells and bacterial vesicles in samples under study. The obtained data may suggest the ability of extracellular vesicles of the mycoplasma to display in plants the features of infection from the viewpoint of virulence criteria—invasivity, infectivity—and toxigenicity—and to favor to bacterial phytopathogenicity.

  17. Active elastohydrodynamics of vesicles in narrow blind constrictions

    Science.gov (United States)

    Fai, T. G.; Kusters, R.; Harting, J.; Rycroft, C. H.; Mahadevan, L.

    2017-11-01

    Fluid-resistance limited transport of vesicles through narrow constrictions is a recurring theme in many biological and engineering applications. Inspired by the motor-driven movement of soft membrane-bound vesicles into closed neuronal dendritic spines, here we study this problem using a combination of passive three-dimensional simulations and a simplified semianalytical theory for the active transport of vesicles forced through constrictions by molecular motors. We show that the motion of these objects is characterized by two dimensionless quantities related to the geometry and to the strength of forcing relative to the vesicle elasticity. We use numerical simulations to characterize the transit time for a vesicle forced by fluid pressure through a constriction in a channel and find that relative to an open channel, transport into a blind end leads to the formation of a smaller forward-flowing lubrication layer that strongly impedes motion. When the fluid pressure forcing is complemented by forces due to molecular motors that are responsible for vesicle trafficking into dendritic spines, we find that the competition between motor forcing and fluid drag results in multistable dynamics reminiscent of the real system. Our study highlights the role of nonlocal hydrodynamic effects in determining the kinetics of vesicular transport in constricted geometries.

  18. Calmodulin stimulation of calcium transport in carrot microsomal vesicles

    International Nuclear Information System (INIS)

    Pierce, W.S.; Sze, H.

    1987-01-01

    ATP-dependent 45 Ca 2+ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca 2+ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca 2+ uptake (at 1.17 g/cc) was not affected by oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca 2+ . These results are consistent with the ER being an important site of intracellular Ca 2+ regulation

  19. Bubble-induced microstreaming: guiding and destroying lipid vesicles

    Science.gov (United States)

    Marmottant, Philippe; Hilgenfeldt, Sascha

    2002-11-01

    Micron-sized bubbles respond with strong oscillations when submitted to ultrasound. This has led to their use as echographic contrast enhancers. The large energy and force densities generated by the collapsing bubbles also make them non-invasive mechanical tools: Recently, it has been reported that the interaction of cavitating bubbles with nearby cells can render the latter permeable to large molecules (sonoporation), suggesting prospects for drug delivery and gene transfection. We have developed a laboratory setup that allows for a controlled study of the interaction of single microbubbles with single lipid bilayer vesicles. Substituting vesicles for cell membranes is advantageous because the mechanical properties of vesicles are well-known. Microscopic observations reveal that vesicles near a bubble follow the vivid streaming motion set up by the bubble. The vesicles "bounce" off the bubble, being periodically accelerated towards and away from it, and undergo well-defined shape deformations along their trajectory in accordance with fluid-dynamical theory. Break-up of vesicles could also be observed.

  20. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  1. Spontaneous soft tissue hematomas.

    Science.gov (United States)

    Dohan, A; Darnige, L; Sapoval, M; Pellerin, O

    2015-01-01

    Spontaneous muscle hematomas are a common and serious complication of anticoagulant treatment. The incidence of this event has increased along with the rise in the number of patients receiving anticoagulants. Radiological management is both diagnostic and interventional. Computed tomography angiography (CTA) is the main tool for the detection of hemorrhage to obtain a positive, topographic diagnosis and determine the severity. Detection of an active leak of contrast material during the arterial or venous phase is an indication for the use of arterial embolization. In addition, the interventional radiological procedure can be planned with CTA. Arterial embolization of the pedicles that are the source of the bleeding is an effective technique. The rate of technical and clinical success is 90% and 86%, respectively. Copyright © 2015 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  2. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  3. Metabolism and the triggering of germination of Bacillus megaterium

    International Nuclear Information System (INIS)

    Scott, I.R.; Ellar, D.J.

    1978-01-01

    L-[2,3- 3 H]Alanine was used to probe for metabolism of alanine during triggering of germination of spores of Bacillus megaterium KM. No detectable incorporation of label into any compound, including water, was found, indicating that any metabolism involving the alanine germinant must be at a very low rate and also that alanine racemase is absent from spores of this strain. Spores were germinated in 3 H 2 0 to find if any of the many metabolic reactions causing irreversible incorporation of 3 H into reaction products took place during triggering og germination. No incorporation was detected until 2-3 min after addition of germinants. It is therefore concluded that a wide variety of metabolic routes, including glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway and amino acid metabolism are either not involved in the reactions causing the triggering of germination or operate at an extremely low rate during this process. (author)

  4. Effects of graphene on seed germination and seedling growth

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ming; Gao, Bin, E-mail: bg55@ufl.edu [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)

    2015-02-15

    The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.

  5. Comparative Analysis of Membrane Vesicles from Three Piscirickettsia salmonis Isolates Reveals Differences in Vesicle Characteristics.

    Directory of Open Access Journals (Sweden)

    Julia I Tandberg

    Full Text Available Membrane vesicles (MVs are spherical particles naturally released from the membrane of Gram-negative bacteria. Bacterial MV production is associated with a range of phenotypes including biofilm formation, horizontal gene transfer, toxin delivery, modulation of host immune responses and virulence. This study reports comparative profiling of MVs from bacterial strains isolated from three widely disperse geographical areas. Mass spectrometry identified 119, 159 and 142 proteins in MVs from three different strains of Piscirickettsia salmonis isolated from salmonids in Chile (LF-89, Norway (NVI 5692 and Canada (NVI 5892, respectively. MV comparison revealed several strain-specific differences related to higher virulence capability for LF-89 MVs, both in vivo and in vitro, and stronger similarities between the NVI 5692 and NVI 5892 MV proteome. The MVs were similar in size and appearance as analyzed by electron microscopy and dynamic light scattering. The MVs from all three strains were internalized by both commercial and primary immune cell cultures, which suggest a potential role of the MVs in the bacterium's utilization of leukocytes. When MVs were injected into an adult zebrafish infection model, an upregulation of several pro-inflammatory genes were observed in spleen and kidney, indicating a modulating effect on the immune system. The present study is the first comparative analysis of P. salmonis derived MVs, highlighting strain-specific vesicle characteristics. The results further illustrate that the MV proteome from one bacterial strain is not representative of all bacterial strains within one species.

  6. Focus on Extracellular Vesicles: Physiological Role and Signalling Properties of Extracellular Membrane Vesicles

    Directory of Open Access Journals (Sweden)

    Nunzio Iraci

    2016-02-01

    Full Text Available Extracellular vesicles (EVs are a heterogeneous population of secreted membrane vesicles, with distinct biogenesis routes, biophysical properties and different functions both in physiological conditions and in disease. The release of EVs is a widespread biological process, which is conserved across species. In recent years, numerous studies have demonstrated that several bioactive molecules are trafficked with(in EVs, such as microRNAs, mRNAs, proteins and lipids. The understanding of their final impact on the biology of specific target cells remains matter of intense debate in the field. Also, EVs have attracted great interest as potential novel cell-free therapeutics. Here we describe the proposed physiological and pathological functions of EVs, with a particular focus on their molecular content. Also, we discuss the advances in the knowledge of the mechanisms regulating the secretion of EV-associated molecules and the specific pathways activated upon interaction with the target cell, highlighting the role of EVs in the context of the immune system and as mediators of the intercellular signalling in the brain.

  7. Asymbiotic germination in three Chloraea species (Orchidaceae) from Chile

    OpenAIRE

    PEREIRA, GUILLERMO; ALBORNOZ, VERÓNICA; ROMERO, CHRISTIAN; LARA, SEBASTIÁN; SÁNCHEZ-OLATE, MANUEL; RÍOS, DARCY; ATALA, CRISTIAN

    2017-01-01

    ABSTRACT Orchids require symbiotic fungi and/or specific conditions to germinate. Asymbiotic techniques have been shown successful for orchid germination. In Chile, Chloraea include many endemic, and potentially ornamental, terrestrial orchid species. In this study, individuals of Chloraea crispa, C. gavilu and C. virescens were manually autopollinated. The resulting capsules were sterilized and seeds were aseptically obtained. We evaluated asymbiotic germination in: Agar Water (AW), Knudson ...

  8. Surface glycosylation profiles of urine extracellular vesicles.

    Directory of Open Access Journals (Sweden)

    Jared Q Gerlach

    Full Text Available Urinary extracellular vesicles (uEVs are released by cells throughout the nephron and contain biomolecules from their cells of origin. Although uEV-associated proteins and RNA have been studied in detail, little information exists regarding uEV glycosylation characteristics. Surface glycosylation profiling by flow cytometry and lectin microarray was applied to uEVs enriched from urine of healthy adults by ultracentrifugation and centrifugal filtration. The carbohydrate specificity of lectin microarray profiles was confirmed by competitive sugar inhibition and carbohydrate-specific enzyme hydrolysis. Glycosylation profiles of uEVs and purified Tamm Horsfall protein were compared. In both flow cytometry and lectin microarray assays, uEVs demonstrated surface binding, at low to moderate intensities, of a broad range of lectins whether prepared by ultracentrifugation or centrifugal filtration. In general, ultracentrifugation-prepared uEVs demonstrated higher lectin binding intensities than centrifugal filtration-prepared uEVs consistent with lesser amounts of co-purified non-vesicular proteins. The surface glycosylation profiles of uEVs showed little inter-individual variation and were distinct from those of Tamm Horsfall protein, which bound a limited number of lectins. In a pilot study, lectin microarray was used to compare uEVs from individuals with autosomal dominant polycystic kidney disease to those of age-matched controls. The lectin microarray profiles of polycystic kidney disease and healthy uEVs showed differences in binding intensity of 6/43 lectins. Our results reveal a complex surface glycosylation profile of uEVs that is accessible to lectin-based analysis following multiple uEV enrichment techniques, is distinct from co-purified Tamm Horsfall protein and may demonstrate disease-specific modifications.

  9. Seminal vesicle involvement at salvage radical prostatectomy.

    Science.gov (United States)

    Meeks, Joshua J; Walker, Marc; Bernstein, Melanie; Eastham, James A

    2013-06-01

    To describe the incidence and clinical outcomes of seminal vesicle invasion (SVI) at salvage radical prostatectomy (SRP) and to describe the accuracy of SV biopsy. As SRP is used after biochemical recurrence (BCR) of prostate cancer after radiotherapy (RT) to gain local oncological control. The SVs receive lower doses of radiation from external-beam RT (EBRT) to avoid rectal exposure and are not targeted with brachytherapy (BT) with low-risk prostate cancer. SRP was performed on 206 men with BCR after RT at a tertiary care institution between 1998 and 2011. Post-RT biopsy and SRP specimens were reviewed by a genitourinary pathologist. SVI was detected in 65 (32%) of 206 patients. No difference was found between EBRT alone (65% vs 63%) and BT (29% vs 31%) with or without EBRT in patients with SVI. Men with SVI had higher rates of cT3 disease (20% vs 8%) and Gleason score ≥ 8 at SRP (52% vs 21%). BCR-free survival at 5 years was 18% and 56% in patients with and without SVI (hazard ratio 2.85, 95% confidence interval 1.87-4.36, P < 0.001), yet the rate of local recurrence was low (11%). Prostate cancer was identified in nine of 18 patients who underwent SV biopsy and was the only location of prostate cancer in two patients. SVI is a prognostic indicator for BCR after SRP, but local recurrence in patients with SVI after SRP remains low. We recommend SV biopsy to improve staging and cancer detection in men with BCR after radiotherapy. © 2013 BJU International.

  10. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  11. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  12. Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.

    Science.gov (United States)

    Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas

    2017-04-01

    Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. The mechanism underlying fast germination of tomato cultivar LA2711.

    Science.gov (United States)

    Yang, Rongchao; Chu, Zhuannan; Zhang, Haijun; Li, Ying; Wang, Jinfang; Li, Dianbo; Weeda, Sarah; Ren, Shuxin; Ouyang, Bo; Guo, Yang-Dong

    2015-09-01

    Seed germination is important for early plant morphogenesis as well as abiotic stress tolerance, and is mainly controlled by the phytohormones abscisic acid (ABA) and gibberellic acid (GA). Our previous studies identified a salt-tolerant tomato cultivar, LA2711, which is also a fast-germinating genotype, compared to its salt-sensitive counterpart, ZS-5. In an effort to further clarify the mechanism underlying this phenomenon, we compared the dynamic levels of ABA and GA4, the transcript abundance of genes involved in their biosynthesis and catabolism as well as signal transduction between the two cultivars. In addition, we tested seed germination sensitivity to ABA and GAs. Our results revealed that insensitivity of seed germination to exogenous ABA and low ABA content in seeds are the physiological mechanisms conferring faster germination rates of LA2711 seeds. SlCYP707A2, which encodes an ABA catabolic enzyme, may play a decisive role in the fast germination rate of LA2711, as it showed a significantly higher level of expression in LA2711 than ZS-5 at most time points tested during germination. The current results will enable us to gain insight into the mechanism(s) regarding seed germination of tomato and the role of fast germination in stress tolerance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Evolution of 'smoke' induced seed germination in pyroendemic plants

    Science.gov (United States)

    Keeley, J. E.; Pausas, J.G.

    2016-01-01

    Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

  15. Germination phenology determines the propensity for facilitation and competition.

    Science.gov (United States)

    Leverett, Lindsay D

    2017-09-01

    A single plant can interact both positively and negatively with its neighbors through the processes of facilitation and competition, respectively. Much of the variation in the balance of facilitation and competition that individuals experience can be explained by the degree of physical stress and the sizes or ages of plants during the interaction. Germination phenology partly controls both of these factors, but its role in defining the facilitation-competition balance has not been explicitly considered. I performed an experiment in a population of the winter annual Arabidopsis thaliana (Brassicaceae) to test whether germinating during physically stressful periods leads to facilitation while germinating during periods that promote growth and reproduction leads to competition. I manipulated germination and neighbor presence across two years in order to quantify the effects of the local plant community on survival, fecundity, and total fitness as a function of germination phenology. Neighbors increased survival when germination occurred under conditions that were unsuitable for survival, but they reduced fecundity in germinants that were otherwise the most fecund. Later germination was associated with facilitation in the first year but competition in the second year. These episodes of facilitation and competition opposed each other, leading to no net effect of neighbors when averaged over all cohorts. These results indicate that variation in germination timing can explain some of the variation in the facilitation-competition balance in plant communities. © 2017 by the Ecological Society of America.

  16. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  17. Sugar-based gemini surfactant with a vesicle-to-micelle transition at acidic pH and a reversible vesicle flocculation near neutral pH

    NARCIS (Netherlands)

    Johnsson, M; Wagenaar, A; Engberts, JBFN

    2003-01-01

    A sugar-based (reduced glucose) gemini surfactant forms vesicles in dilute aqueous solution near neutral pH. At lower pH, there is a vesicle-to-micelle transition within a narrow pH region (pH 6.0-5.6). The vesicles are transformed into large cylindrical micelles that in turn are transformed into

  18. Stimulation of germination of conidium Aspergillus niger, a citric acid producer, under the action of mutagenic factors

    International Nuclear Information System (INIS)

    Golubtsova, V.M.; Shcherbakova, E.Ya.; Smirnov, V.A.; Runkovskaya, L.Ya.

    1976-01-01

    The action of low doses of various mutagens, namely, 2% cyclophosphane solution (30 min), 1% thiophosphamide solution (30 min), 0.05% nitrosomethylurea solution (30 and 60 min), γ-rays (10 krads) and UV-rays (10000 erg/mm 2 ) stimulates germination of conidium Aspergillus niger, a citric acid producer. At the above-mentioned doses of mutagens, a minor quantity of morphological varieties are formed, and the variability value of acid production by Asp. niger is maintained at the spontaneous level

  19. The role of hull in germination and salinity tolerance in some ...

    African Journals Online (AJOL)

    hulled and dehulled) of sunflower seeds of Opal, Shelly (Confectionary) and Pactol (Oily) were tested to determine the effects of the hull on salinity tolerance during germination. Germination percentage (%), mean germination time (day), root and ...

  20. Effects of salt stress on germination of some maize (Zea mays L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... Key words: Maize, NaCl, germination percentage, stress tolerance ındex, germination ındex. .... interactions between salt treatments and cultivars. This ..... Hormones and Abiotic Stresses on Germination, Growth and Phos-.

  1. Calculating germination measurements and organizing spreadsheets

    OpenAIRE

    Ranal, Marli A.; Santana, Denise Garcia de; Ferreira, Wanessa Resende; Mendes-Rodrigues, Clesnan

    2009-01-01

    With the objective to minimize difficulties for beginners we are proposing the use of a conventional spreadsheet for the calculations of the main germination (or emergence) measurements, the organization of the final data for the statistical analysis and some electronic commands involved in these steps. Com o objetivo de minimizar as dificuldades dos iniciantes, estamos propondo o uso de planilhas eletrônicas convencionais para o cálculo das principais medidas de germinação (ou emergência)...

  2. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  3. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  4. Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

    Science.gov (United States)

    Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

    2014-01-01

    Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

  5. Genetics Home Reference: primary spontaneous pneumothorax

    Science.gov (United States)

    ... Home Health Conditions Primary spontaneous pneumothorax Primary spontaneous pneumothorax Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Primary spontaneous pneumothorax is an abnormal accumulation of air in the ...

  6. Overall energy conversion efficiency of a photosynthetic vesicle

    Energy Technology Data Exchange (ETDEWEB)

    Sener, Melih [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Strumpfer, Johan [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States; Singharoy, Abhishek [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Hunter, C. Neil [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom; Schulten, Klaus [Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, United States; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, United States; Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, United States

    2016-08-26

    The chromatophore of purple bacteria is an intracellular spherical vesicle that exists in numerous copies in the cell and that efficiently converts sunlight into ATP synthesis, operating typically under low light conditions. Building on an atomic-level structural model of a low-light-adapted chromatophore vesicle from Rhodobacter sphaeroides, we investigate the cooperation between more than a hundred protein complexes in the vesicle. The steady-state ATP production rate as a function of incident light intensity is determined after identifying quinol turnover at the cytochrome bc1 complex (cytbc1) as rate limiting and assuming that the quinone/quinol pool of about 900 molecules acts in a quasi-stationary state. For an illumination condition equivalent to 1% of full sunlight, the vesicle exhibits an ATP production rate of 82 ATP molecules/s. The energy conversion efficiency of ATP synthesis at illuminations corresponding to 1%–5% of full sunlight is calculated to be 0.12-0.04, respectively. The vesicle stoichiometry, evolutionarily adapted to the low light intensities in the habitat of purple bacteria, is suboptimal for steady-state ATP turnover for the benefit of protection against over-illumination.

  7. Adhesion signals of phospholipid vesicles at an electrified interface.

    Science.gov (United States)

    DeNardis, Nadica Ivošević; Žutić, Vera; Svetličić, Vesna; Frkanec, Ruža

    2012-09-01

    General adhesion behavior of phospholipid vesicles was examined in a wide range of potentials at the mercury electrode by recording time-resolved adhesion signals. It was demonstrated that adhesion-based detection is sensitive to polar headgroups in phospholipid vesicles. We identified a narrow potential window around the point of zero charge of the electrode where the interaction of polar headgroups of phosphatidylcholine vesicles with the substrate is manifested in the form of bidirectional signals. The bidirectional signal is composed of the charge flow due to the nonspecific interaction of vesicle adhesion and spreading and of the charge flow due to a specific interaction of the negatively charged electrode and the most exposed positively charged choline headgroups. These signals are expected to appear only when the electrode surface charge density is less than the surface charge density of the choline groups at the contact interface. In comparison, for the negatively charged phosphatidylserine vesicles, we identified the potential window at the mercury electrode where charge compensation takes place, and bidirectional signals were not detected.

  8. Models for randomly distributed nanoscopic domains on spherical vesicles

    Science.gov (United States)

    Anghel, Vinicius N. P.; Bolmatov, Dima; Katsaras, John

    2018-06-01

    The existence of lipid domains in the plasma membrane of biological systems has proven controversial, primarily due to their nanoscopic size—a length scale difficult to interrogate with most commonly used experimental techniques. Scattering techniques have recently proven capable of studying nanoscopic lipid domains populating spherical vesicles. However, the development of analytical methods able of predicting and analyzing domain pair correlations from such experiments has not kept pace. Here, we developed models for the random distribution of monodisperse, circular nanoscopic domains averaged on the surface of a spherical vesicle. Specifically, the models take into account (i) intradomain correlations corresponding to form factors and interdomain correlations corresponding to pair distribution functions, and (ii) the analytical computation of interdomain correlations for cases of two and three domains on a spherical vesicle. In the case of more than three domains, these correlations are treated either by Monte Carlo simulations or by spherical analogs of the Ornstein-Zernike and Percus-Yevick (PY) equations. Importantly, the spherical analog of the PY equation works best in the case of nanoscopic size domains, a length scale that is mostly inaccessible by experimental approaches such as, for example, fluorescent techniques and optical microscopies. The analytical form factors and structure factors of nanoscopic domains populating a spherical vesicle provide a new and important framework for the quantitative analysis of experimental data from commonly studied phase-separated vesicles used in a wide range of biophysical studies.

  9. Ziprasidone-induced spontaneous orgasm.

    Science.gov (United States)

    Boora, K; Chiappone, K; Dubovsky, S; Xu, J

    2010-06-01

    Neuroleptic treatment in schizophrenic patients has been associated with sexual dysfunction, including impotence and decreased libido. Spontaneous ejaculation without sexual arousal during typical antipsychotic treatment is a rare condition that has been described with zuclopentixol, trifluoperazine, and thiothixene. Here, we are reporting a case of spontaneous orgasm with ziprasidone in a bipolar patient. This patient began to repeatedly experience spontaneous sexual arousal and orgasm, which she had never experienced in the past. Ziprasidone might be causing an increase in sexual orgasm by 5-HT2 receptor antagonism, which preclinical evidence suggests that it facilitates dopamine release in the cortex.

  10. Comparative seed germination traits in alpine and subalpine grasslands: higher elevations are associated with warmer germination temperatures.

    Science.gov (United States)

    Fernández-Pascual, E; Jiménez-Alfaro, B; Bueno, Á

    2017-01-01

    Seed germination traits in alpine grasslands are poorly understood, despite the sensitivity of these communities to climate change. We hypothesise that germination traits predict species occurrence along the alpine-subalpine elevation gradient. Phylogenetic comparative analyses were performed using fresh seeds of 22 species from alpine and subalpine grasslands (1600-2400 m) of the Cantabrian Mountains, Spain (43° N, 5° W). Laboratory experiments were conducted to characterise germinability, optimum germination temperature and effect of cold and warm stratification on dormancy breaking. Variability in these traits was reduced by phylogenetic principal component analysis (phyl.PCA). Phylogenetic generalised least squares regression (PGLS) was used to fit a model in which species average elevation was predicted from their position on the PCA axes. Most subalpine species germinated in snow-like conditions, whereas most alpine species needed accumulation of warm temperatures. Phylogenetic signal was low. PCA1 ordered species according to overall germinability, whilst PCA2 ordered them according to preference for warm or cold germination. PCA2 significantly predicted species occurrence in the alpine-subalpine gradient, as higher elevation species tended to have warmer germination preferences. Our results show that germination traits in high-mountain grasslands are closely linked to the alpine-subalpine gradient. Alpine species, especially those from stripped and wind-edge communities, prefer warmer germination niches, suggesting that summer emergence prevents frost damage during seedling establishment. In contrast, alpine snowfield and subalpine grassland plants have cold germination niches, indicating that winter emergence may occur under snow to avoid drought stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Comparative Study of Pre-Germination Treatments and their Effects ...

    African Journals Online (AJOL)

    FIRST LADY

    of leaves (10.05) respectively. Pre-germination treatments of seeds soaked in running water (SRW) for 24 hours were found to be more effective in seedlings growth and biomass production. Keywords: Tectona grandis, pre-germination treatment, seed dormancy, seedling growth. Introduction. Tectona grandis is one of the ...

  12. The pleiotropic effects of the seed germination inhibitor germostatin.

    Science.gov (United States)

    Ye, Yajin; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination.

  13. Germination phenology of some Great Basin native annual forb species

    Science.gov (United States)

    Tara A. Forbis

    2010-01-01

    Great Basin native plant communities are being replaced by the annual invasive cheatgrass Bromus tectorum. Cheatgrass exhibits a germination syndrome that is characteristic of facultative winter annuals. Although perennials dominate these communities, native annuals are present at many sites. Germination timing is often an important predictor of competitive...

  14. Investigating the Influence of Karrikins on Seed Germination

    Science.gov (United States)

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  15. Proteins induced by salt stress in tomato germinating seeds

    International Nuclear Information System (INIS)

    Torres-Shumann, S.; Godoy, J.A.; del Pozo, O.; Pintor-Toro, J.A.

    1989-01-01

    Salt effects on protein synthesis in tomato germinating seeds were investigated by two-dimensional polyacrilamide gel electrophoresis of proteins labeled in vivo with ( 35 S)-Methionine. Seeds germinating in NaCl were analyzed at three germination stages (4mm long radicals, 15mm long radicles and expanding cotyledons) and compared to those germinating in water. At the first germination stage several basic proteins of M.W. 13Kd, 16Kd, 17Kd and 18Kd were detected in only salt germinating seeds. Other basic proteins of M.W. 12Kd, 50Kd and 54Kd were salt-induced at the second and third stage of germination. One 14Kd acid protein is observed in every assayed stage and shows several phosphorylated forms. The levels of expression of these proteins are directly correlated to assayed NaCl concentrations. All of these proteins, except 17Kd, are also induced by abscisic acid (ABA) in the same germination stages. A cooperative effect on the synthesis of these proteins is observed when both ABA and NaCl are present

  16. Germination of Themeda triandra (Kangaroo grass) as affected by ...

    African Journals Online (AJOL)

    Low rainfall in range areas restricts germination, growth and development of majority of range grasses. However, germination and establishment potential of forage grasses vary and depends on environmental conditions. Themeda triandra is an excellent known grass to grow under different environmental conditions.

  17. Germination of several groundnut cultivars in relation to incidence of ...

    African Journals Online (AJOL)

    This experiment is concerned with the germination of nine cultivars of groundnut grown in Nigeria in relation to incidence of fungi. The cultivars were NHK 5V8, NUTII 288, Samnut 10, 11, 21, 22, 23, 24 and MK 373. Germination potential was assessed after 10 days of planting in petri-dishes. Parameters such as seedling ...

  18. Differentiation inside multicelled macroconidia of Fusarium culmorum during early germination

    NARCIS (Netherlands)

    Chitarra, Gilma S; Breeuwer, Pieter; Rombouts, Frans M; Abee, Tjakko; Dijksterhuis, Jan

    Multicelled conidia are formed by many fungal species, but germination of these spores is scarcely studied. Here, the germination and the effects of antimicrobials on multicompartment macroconidia of Fusarium culmorum were investigated. Germ-tube formation was mostly from apical compartments. The

  19. Differentiation inside multicelled macroconidia of Fusarium culmorum during early germination

    NARCIS (Netherlands)

    Chitarra, G.S.; Breeuwer, P.; Rombouts, F.M.; Abee, T.; Dijksterhuis, J.

    2005-01-01

    Multicelled conidia are formed by many fungal species, but germination of these spores is scarcely studied. Here, the germination and the effects of antimicrobials on multicompartment macroconidia of Fusarium culmorum were investigated. Germ-tube formation was mostly from apical compartments. The

  20. Effect of exogenous gibberellic acid on germination, seedling growth ...

    African Journals Online (AJOL)

    The effect of gibberellic acid on germination and seedling growth of lettuce variety, Vista, under salinity conditions was studied. A reduction in germination percentage, roots and shoots length and fresh weight were observed under salt stress. At the same time, acid phosphatase and phytase activities in roots were reduced ...

  1. Improving the seed germination of little bluestem with selection

    Science.gov (United States)

    Rapid seed germination is an important characteristic when it comes to plant stand establishment under variable environmental conditions. This research was designed to improve the seed germination of six experimental Syn-0 lines of little bluestem [Schizachyrium scoparium (Michx.) Nash]. Two cycle...

  2. Modelling the effect of temperature on seed germination in some ...

    African Journals Online (AJOL)

    The prediction of germination percentage (GP) and germination speed (GS) of the seeds for some cucurbits (watermelon, melon, cucumber, summer squash, pumpkin and winter squash) was investigated by mathematical model based on temperature. The model, D = [a - (b x T) + (c x T2)] of Uzun et al. (2001), was adapted ...

  3. Effects of Sowing Media and Sowing Depth on Germination and ...

    African Journals Online (AJOL)

    This study examines the effect of sowing media and sowing depth on the germination and growth of Lecanodiscus cupanoides (Planch.Ex Benth). The germination of L. cupanoides seed was significantly affected by sowing depth and sowing medium at p=0.05. The result of various sowing media and sowing depth showed ...

  4. Asymbiotic germination of immature embryos of a medicinally ...

    African Journals Online (AJOL)

    The immature embryos (28 weeks after pollination) were inoculated on M (Mitra et al., 1976), and PDA (Potato Dextrose Agar) media, with and without different growth additives. The seeds showed positive germination response in both the nutrient media but the frequency and onset of germination response and associated ...

  5. The effect of different treatments on improving seed germination ...

    African Journals Online (AJOL)

    Creating optimal conditions for germination of medicinal plants seed is essential for their cultivation. Therefore, to evaluate the effect of different treatments on seed germination of two medicinal species, Descurainia sophia and Plantago ovata collected in 2009 from Tehran Province, an experiment with a factorial ...

  6. Full Length Research Paper Seed germination and in vitro plant ...

    African Journals Online (AJOL)

    Parkia biglobosa is an important leguminous forest species which is being threatened of going into extinction in Senegal. To preserve this genetic resource of great economic value, studies on germination were carried out and in vitro conservation option through tissue culture technique was adopted. 100% of germination ...

  7. Effects of animal's rumen juice on seed germination of Vicia ...

    African Journals Online (AJOL)

    To help understand the effects of grazing on seed germination characteristics of Vicia angustifolia L., we conducted a laboratory germination experiment of V. angustifolia L., which is a main companion species of Leguminosae family in alpine grassland of the Qinghai-Tibetan Plateau, using Yak and Tibetan sheep rumen ...

  8. Millipede damage to germinating acorns of northern red oak

    Science.gov (United States)

    Jimmy R. Galford; L. R. Auchmoody; Russell S. Walters; H. Clay. Smith; H. Clay. Smith

    1992-01-01

    Millipedes have not been reported as pests of germinating acorns. Studies in Pennsylvania on the impact of insects on northern red (Quercus rubra L. seedling establishment revealed that the millipede Ptyoiulus impressus (Say) damaged the radicles of germinating acorns. Up to 17 percent of the acorn radicles in areas with heavy acorn crops were damaged in 1'991....

  9. Effects of seed fermentation method on seed germination and vigor ...

    African Journals Online (AJOL)

    The present study was conducted to examine the influence of Lagenaria siceraria seed fermentation method on seed germination and vigor. Three seed fermentation methods (fermented in ambient air, plastic bag stored in ambient or in plastic bag buried) were tested on two cultivars during two years. Seed germination and ...

  10. Allelopathic effect of Jatropha curcas (Lin) leachate on germination ...

    African Journals Online (AJOL)

    Laboratory study was conducted using sterilized petri dishes with double layer of Whatman filter paper at averagely 27oC and 70% humidity. An interval of 24, 48, 76 and 92 hours were recorded on germination studies while radicle and shoot lengths at 92nhours respectively. Decreased in germination percentage, shoot ...

  11. The role of seed priming in improving seed germination and ...

    African Journals Online (AJOL)

    Salinity is considered as a major abiotic stress affecting germination, seedling growth and crop production in arid and semi-arid regions. Many techniques are used to improve tolerance to salinity. Priming is believed to be an effective technique that increases germination, plant growth and improve yield of several ...

  12. IAA production during germination of Orobanche spp. seeds.

    Science.gov (United States)

    Slavov, Slavtcho; van Onckelen, Henry; Batchvarova, Rossitza; Atanassov, Atanas; Prinsen, Els

    2004-07-01

    Broomrapes (Orobanche spp.) are parasitic plants, whose growth and development fully depend on the nutritional connection established between the parasite and the roots of the respective host plant. Phytohormones are known to play a role in establishing the specific Orobanche-host plant interaction. The first step in the interaction is seed germination triggered by a germination stimulant secreted by the host-plant roots. We quantified indole-3-acetic acid (IAA) and abscisic acid (ABA) during the seed germination of tobacco broomrape (Orobanche ramosa) and sunflower broomrape (O. cumana). IAA was mainly released from Orobanche seeds in host-parasite interactions as compared to non-host-parasite interactions. Moreover, germinating seeds of O. ramosa released IAA as early as 24 h after the seeds were exposed to the germination stimulant, even before development of the germ tube. ABA levels remained unchanged during the germination of the parasites' seeds. The results presented here show that IAA production is probably part of a mechanism triggering germination upon the induction by the host factor, thus resulting in seed germination.

  13. Germination potential index of Sindh rice cultivars on biochemical ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... Alpha amylase activities were found to be directly correlated with germination percentage. Gradual increase in reducing sugars along with α-amylase activity was observed, while total ... seed vigor and alpha amylase activity along with germination period. .... strates for energy generation for fast and uniform.

  14. Temperature and substrate on Plukenetia volubilis L. seed germination

    Directory of Open Access Journals (Sweden)

    Givanildo Z. da Silva

    Full Text Available ABSTRACT The objective of this work was to evaluate the effect of temperature and substrate on the germination of P. volubilis seeds. Seeds harvested from 25 matrix plants were submitted, in two studies, to conditions of (i sowing in rolled paper towel at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 °C, for the evaluation of germination, first count of germination, germination speed index and mean time for germination, and (ii sowing in the substrates paper towel, sand, Bioplant®, Bioplant® and micron, superfine, fine, medium and coarse vermiculite. The same evaluations mentioned in the first study were conducted at the temperature of 30 oC, as well as plant growth. The treatment replicates were distributed in a completely randomized block design and the effects of temperature were compared by polynomial regression analysis. The substrates were compared by the Scott-Knott test at 0.05 probability level. The data show that the ideal range of temperature for the germination of P. volubilis is between 25 and 30 °C. The temperature of 20 °C is the minimum for germination and those above 35 °C are lethal to these seeds. The most favorable substrate for P. volubilis seed germination is micron or fine vermiculite.

  15. Effects of hydropriming on seed germination and seedling growth in ...

    African Journals Online (AJOL)

    The germination of Salvia officinalis L. (sage) seeds is a problem of great concern that may be overcome by employing seed priming techniques. Seed priming is an efficient technique for improvement of seed vigor, increasing germination and seedling growth. Little information has been reported on seedling development ...

  16. Tetrazolium chloride as an indicator of pine pollen germinability

    Science.gov (United States)

    Stanton A. Cook; Robert G. Stanley

    1960-01-01

    Controlled pollination in forest tree breeding requires pollen of known germination capacity. Methods of determining pollen viability include germination in a hanging drop, in a moist atmosphere, on agar gel, or in a sugar solution (DUFFIELD, 1954; DILLON et al., 1957). Errors commonly arise in the application of these techniques because maximum...

  17. Variability of Germinative Potential among Pathogenic Species of Aspergillus

    OpenAIRE

    Araujo, Ricardo; Rodrigues, Acacio Gonçalves

    2004-01-01

    The objective of our study was to evaluate parameters influencing the germination of Aspergillus conidia. Inoculum concentration and age significantly influenced germination. Different incubation temperatures revealed significant differences among Aspergillus species. The internal human milieu provides the ideal conditions for the development of invasive disease by Aspergillus fumigatus but restricts invasion by Aspergillus flavus and Aspergillus niger.

  18. Mapping QTLs for submergence tolerance during germination in rice

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... Key words: Oryza sativa L, anaerobic germination, QTL analysis. INTRODUCTION. Two main ... The study was conducted at NG-01 greenhouse, Genome and. Mapping (GML), the .... ABC transporter family protein ..... differences of germination habits in rice seeds with special reference to plant breeding (in ...

  19. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... This study aims to determine the germination characteristics, pollen tube developments, effects of germination media and temperature and incubation durations of the pollens obtained from the four clones (11342, 11344, 11345 and 11351) of Cedrus libani A. Rich. (Lebanon Cedrus) obtained from clonal.

  20. Salt tolerance of physalis during germination and seedling growth

    International Nuclear Information System (INIS)

    Yildirim, E.; Karlidag, H.

    2011-01-01

    The study was conducted to evaluate the effect of NaCl salinity on germination and emergence of Physalis ixocarpa and Physalis peruviana. Seeds of P. ixocarpa and P. peruviana were germinated by the use of 0, 30, 60, 90, 120 and 180 mM NaCl solutions in petri dishes. Final germination percentage (FGP) decreased with the increase in NaCl concentration. Both species germinated at the ranges of salinity. P. peruviana gave the greater germination percentages under salt stress than P. ixocarpa. NaCl salinity at different concentrations adversely affected germination rates. For seedling growth, seeds of both species were sown at 10 mm depth in plastic trays filled with peat to determine final emergence percentage (FEP). The trays were irrigated manually to saturation every day with 0, 30, 60, 90, 120, 150 or 180 mM NaCl solutions to maintain the level of salinity. Salinity affected seed emergence and seedlings growth more than seed germination. The study showed that no emergence of Physalis was observed at 90, 120 and 180 mM NaCl salinity. Fresh and dry weights of normal seedlings were also evaluated. Salt stress significantly decreased the plant fresh and dry weight of both species. Based on the results of the experiment, it can be concluded that seedling emergence and growth is more sensitive to salt stress than seed germination in Physalis. (author)

  1. Reinstatement of "germinal epithelium" of the ovary

    Directory of Open Access Journals (Sweden)

    Nishida Naoyo

    2006-08-01

    Full Text Available Abstract Background The existing dogma that the former term ovarian "germinal epithelium" resulted from a mistaken belief that it could give rise to new germ cells is now strongly challenged. Discussion Two years ago, a research group of the University of Tennessee led by Antonin Bukovsky successfully demonstrated the oogenic process from the human ovarian covering epithelium now commonly called the ovarian surface epithelium. They showed the new oocyte with zona pellucida and granulosa cells, both originated from the surface epithelium arising from mesenchymal cells in the tunica albuginea, and stressed that the human ovary could form primary follicles throughout the reproductive period. This gives a big impact not only to the field of reproductive medicine, but also to the oncologic area. The surface epithelium is regarded as the major source of ovarian cancers, and most of the neoplasms exhibit the histology resembling müllerian epithelia. Since the differentiating capability of the surface epithelium has now expanded, the histologic range of the neoplasms in this category may extend to include both germ cell tumors and sex cord-stromal cell tumors. Summary Since the oogenic capability of ovarian surface cells has been proven, it is now believed that the oocytes can originate from them. The term "germinal epithelium", hence, might reasonably be reinstated.

  2. Extracellular Vesicles in Brain Tumors and Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Federica Ciregia

    2017-08-01

    Full Text Available Extracellular vesicles (EVs can be classified into apoptotic bodies, microvesicles (MVs, and exosomes, based on their origin or size. Exosomes are the smallest and best characterized vesicles which derived from the endosomal system. These vesicles are released from many different cell types including neuronal cells and their functions in the nervous system are investigated. They have been proposed as novel means for intercellular communication, which takes part not only to the normal neuronal physiology but also to the transmission of pathogenic proteins. Indeed, exosomes are fundamental to assemble and transport proteins during development, but they can also transfer neurotoxic misfolded proteins in pathogenesis. The present review will focus on their roles in neurological diseases, specifically brain tumors, such as glioblastoma (GBM, neuroblastoma (NB, medulloblastoma (MB, and metastatic brain tumors and chronic neurodegenerative diseases, such as Alzheimer, Parkinson, multiple sclerosis (MS, amyotrophic lateral sclerosis (ALS, Huntington, and Prion diseseases highlighting their involvement in spreading neurotoxicity, in therapeutics, and in pathogenesis.

  3. Irregular bilayer structure in vesicles prepared from Halobacterium cutirubrum lipids

    Science.gov (United States)

    Lanyi, J. K.

    1974-01-01

    Fluorescent probes were used to study the structure of the cell envelope of Halobacterium cutirubrum, and, in particular, to explore the effect of the heterogeneity of the lipids in this organism on the structure of the bilayers. The fluorescence polarization of perylene was followed in vesicles of unfractionated lipids and polar lipids as a function of temperature in 3.4 M solutions of NaCl, NaNO3, and KSCN, and it was found that vesicles of unfractionated lipids were more perturbed by chaotropic agents than polar lipids. The dependence of the relaxation times of perylene on temperature was studied in cell envelopes and in vesicles prepared from polar lipids, unfractionated lipids, and mixtures of polar and neutral lipids.

  4. Starch bioengineering affects cereal grain germination and seedling establishment

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel

    2014-01-01

    Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...... structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics...... showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated...

  5. Germination, carbohydrate composition and vigor of cryopreserved Caesalpinia echinata seeds

    Directory of Open Access Journals (Sweden)

    Rafael Fonsêca Zanotti

    2012-10-01

    Full Text Available The present study investigated the germination and vigor of Caesalpinia echinata (Brazilwood seeds stored at negative temperatures. Recently harvested seeds were cryopreserved at -18º or -196ºC and periodically evaluated for germination, seed vigor and carbohydrate composition. The temperatures did not influence the germination percentages or vigor. The germination percentage decreased from 88% in recently harvested seeds to 60% after 730 days of storage. The different temperature and storage times tested did not affect the vigor seed germination as indicated by the measures of plant growth and survival. The different temperatures used did not cause changes in the carbohydrate composition. The tegument cell walls were rich in lignin, arabinose and xylose. The cytoplasm of the cotyledons and embryos had high levels of glucose, fructose, and sucrose. The cryopreservation technique here presented was effective in the conservation of Brazilwood seeds for the medium term.

  6. Vesicle biomechanics in a time-varying magnetic field.

    Science.gov (United States)

    Ye, Hui; Curcuru, Austen

    2015-01-01

    Cells exhibit distortion when exposed to a strong electric field, suggesting that the field imposes control over cellular biomechanics. Closed pure lipid bilayer membranes (vesicles) have been widely used for the experimental and theoretical studies of cellular biomechanics under this electrodeformation. An alternative method used to generate an electric field is by electromagnetic induction with a time-varying magnetic field. References reporting the magnetic control of cellular mechanics have recently emerged. However, theoretical analysis of the cellular mechanics under a time-varying magnetic field is inadequate. We developed an analytical theory to investigate the biomechanics of a modeled vesicle under a time-varying magnetic field. Following previous publications and to simplify the calculation, this model treated the inner and suspending media as lossy dielectrics, the membrane thickness set at zero, and the electric resistance of the membrane assumed to be negligible. This work provided the first analytical solutions for the surface charges, electric field, radial pressure, overall translational forces, and rotational torques introduced on a vesicle by the time-varying magnetic field. Frequency responses of these measures were analyzed, particularly the frequency used clinically by transcranial magnetic stimulation (TMS). The induced surface charges interacted with the electric field to produce a biomechanical impact upon the vesicle. The distribution of the induced surface charges depended on the orientation of the coil and field frequency. The densities of these charges were trivial at low frequency ranges, but significant at high frequency ranges. The direction of the radial force on the vesicle was dependent on the conductivity ratio between the vesicle and the medium. At relatively low frequencies (biomechanics under a time-varying magnetic field. Biological effects of clinical TMS are not likely to occur via alteration of the biomechanics of brain

  7. Quark potential of spontaneous strings

    International Nuclear Information System (INIS)

    German, G.; Kleinert, H.

    1989-01-01

    The authors present some recent developments in string models with an extrinsic curvature term in action. Particular emphasis is placed upon the static quark potential and on the thermal deconfinement properties of spontaneous strings

  8. Hematome Extra - Dural Rachidien Spontane

    Directory of Open Access Journals (Sweden)

    Cl. Gros

    1967-01-01

    Full Text Available Four personal cases of Spontaneous Spinal Epidurdl Hemerrhage are Reported. And 29 additional cases have been analysed by reviewing the literature. The clinical radiologcal and surgical aspects were discussed.

  9. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  10. Association mapping of soybean seed germination under salt stress.

    Science.gov (United States)

    Kan, Guizhen; Zhang, Wei; Yang, Wenming; Ma, Deyuan; Zhang, Dan; Hao, Derong; Hu, Zhenbin; Yu, Deyue

    2015-12-01

    Soil salinity is a serious threat to agriculture sustainability worldwide. Seed germination is a critical phase that ensures the successful establishment and productivity of soybeans in saline soils. However, little information is available regarding soybean salt tolerance at the germination stage. The objective of this study was to identify the genetic mechanisms of soybean seed germination under salt stress. One natural population consisting of 191 soybean landraces was used in this study. Soybean seeds produced in four environments were used to evaluate the salt tolerance at their germination stage. Using 1142 single-nucleotide polymorphisms (SNPs), the molecular markers associated with salt tolerance were detected by genome-wide association analysis. Eight SNP-trait associations and 13 suggestive SNP-trait associations were identified using a mixed linear model and the TASSEL 4.0 software. Eight SNPs or suggestive SNPs were co-associated with two salt tolerance indices, namely (1) the ratio of the germination index under salt conditions to the germination index under no-salt conditions (ST-GI) and (2) the ratio of the germination rate under salt conditions to the germination rate under no-salt conditions (ST-GR). One SNP (BARC-021347-04042) was significantly associated with these two traits (ST-GI and ST-GR). In addition, nine possible candidate genes were located in or near the genetic region where the above markers were mapped. Of these, five genes, Glyma08g12400.1, Glyma08g09730.1, Glyma18g47140.1, Glyma09g00460.1, and Glyma09g00490.3, were verified in response to salt stress at the germination stage. The SNPs detected could facilitate a better understanding of the genetic basis of soybean salt tolerance at the germination stage, and the marker BARC-021347-04042 could contribute to future breeding for soybean salt tolerance by marker-assisted selection.

  11. Pre-treating Seed to Enhance Germination of Desert Shrubs

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler; D. C. Anderson; D. J. Hansen

    2002-06-01

    Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.

  12. Kinetic partitioning between aggregation and vesicle permeabilization by modified ADan

    DEFF Research Database (Denmark)

    Nesgaard, Lise W.; Vad, Brian; Christiansen, Gunna

    2009-01-01

    The neurodegenerative illness Familial Danish Dementia (FDD) is linked to formation and aggregation of the 34-residue ADan peptide, whose cytotoxicity may be mediated by membrane interactions. Here we characterize the derived peptide SerADan, in which the two cysteines found in ADan have been....... Aggregation is prevented at neutral/acidic pH and low ionic strength by anionic lipid vesicles. These vesicles are permeabilized by monomeric SerADan assembling on the membrane to form stable beta-sheet structures which are different from the solution aggregates. In contrast, solution ageing of SerADan first...

  13. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  14. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  15. Spontaneous calf haematoma: case report.

    Science.gov (United States)

    Zubaidah, N H; Liew, N C

    2014-02-01

    Spontaneous calf haematoma is a rare condition and few case reports have been published in the English literature. Common conditions like deep vein thrombosis and traumatic gastrocnemius muscle tear need to be considered when a patient presents with unilateral calf swelling and tenderness. Ultrasound and Magnetic Resonance Imaging are essential for confirmation of diagnosis. The purpose of this paper is to report on a rare case of spontaneous calf hematoma and its diagnosis and management.

  16. Quantifying emissions from spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

  17. PsVPS1, a dynamin-related protein, is involved in cyst germination and soybean infection of Phytophthora sojae.

    Directory of Open Access Journals (Sweden)

    Delong Li

    Full Text Available Plant pathogens secrete effector proteins to suppress plant immunity. However, the mechanism by which oomycete pathogens deliver effector proteins during plant infection remains unknown. In this report, we characterized a Phytophthora sojae vps1 gene. This gene encodes a homolog of the Saccharomyces cerevisiae vacuolar protein sorting gene vps1 that mediates budding of clathrin-coated vesicles from the late Golgi, which are diverted from the general secretory pathway to the vacuole. PsVPS1-silenced mutants were generated using polyethylene glycol-mediated protoplast stable transformation and were viable but had reduced extracellular protein activity. The PsVPS1-silenced mutants showed impaired hyphal growth, and the shapes of the vacuoles were highly fragmented. Silencing of PsVPS1 affected cyst germination as well as the polarized growth of germinated cysts. Silenced mutants showed impaired invasion of susceptible soybean plants regardless of wounding. These results suggest that PsVPS1 is involved in vacuole morphology and cyst development. Moreover, it is essential for the virulence of P. sojae and extracellular protein secretion.

  18. Vesicle interactions with polyamino acids and antibody: in vitro and in vivo studies

    International Nuclear Information System (INIS)

    Dunnick, J.K.; McDougall, I.R.; Aragon, S.; Goris, M.L.; Kriss, J.P.

    1975-01-01

    Artificial spherules or vesicles of 900 A in diameter formed from phosphatidylcholine and gangliosides and enclosing /sup 99m/TcO 4 - (standard preparation) survive intact in the circulation of the mouse. Polyamino acids and protein have been incorporated into and onto the vesicles; such vesicles remain intact as determined by diffusion dialysis studies and by electron paramagnetic resonance studies of vesicles enclosing spin label. In studying the distribution of polyamino acid-vesicles and protein vesicles in vivo, it was found that the latter distribute differently from standard vesicles or free protein alone whereas aromatic polyamino acid-vesicles concentrate in the liver and spleen to a greater extent than standard vesicles. The permeability and stability characteristics of vesicles may be preserved when they are modified by the addition of protein or polyamino acids and that such modification of vesicles may be associated with an alteration of their fate in vivo. The potential exists to use vesicles as carriers of radiopharmaceuticals and other drugs and to direct the vesicles preferentially to tissue targets in vivo. (U.S.)

  19. Salinity on the germination of seed and index of germination speed of three ornamental species

    Directory of Open Access Journals (Sweden)

    Marcos Vieira Ferraz

    2016-09-01

    Full Text Available Salinity is a factor that interferes on seed germination in most species. The objective of this work was to study the effects of different concentrations of NaCl on the emergence and vigor of Petunia x hybrida hort. Vilm E. ex., Torenia fournieri Lind and Tagetes patula L. seedlings. The experimental design was entirely randomized with five treatments (five concentrations of NaCl: zero, 25, 50, 75 and 100 mM and four replications of 50 seeds, for each species. The seeds were germinated in germitest paper at the alternating temperature of 20-30°C. Emergence (% and Emergence Rate (ER were performed daily until 14 days. Salt stress caused negative effects on the emergence and vigor on seedlings of these three ornamentals species.

  20. Germination conditions affect selected quality of composite wheat-germinated brown rice flour and bread formulations.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Prinyawiwatkul, Witoon; Tungtrakul, Patcharee

    2010-08-01

    Brown rice has been reported to be more nutritious after germination. Germinated brown rice flours (GBRFs) from different steeping conditions (in distilled water [DI, pH 6.8] or in a buffer solution [pH 3] for either 24 or 48 h at 35 degrees C) were evaluated in this study. GBRF obtained from brown rice steeped at pH 3 for 48 h contained the highest amount of free gamma aminobutyric acid (GABA; 67 mg/100 g flour). The composite flour (wheat-GBRF) at a ratio of 70 : 30 exhibited significantly lower peak viscosity (PV) (56.99 - 132.45 RVU) with higher alpha-amylase activity (SN = 696 - 1826) compared with those of wheat flour (control) (PV = 136.46 RVU and SN = 1976). Bread formulations, containing 30% GBRF, had lower loaf volume and greater hardness (P rice flour (BRF). Acceptability scores for aroma, taste, and flavor of breads prepared with or without GBRFs (30% substitution) were not significantly different, with the mean score ranging from 6.1 (like slightly) to 7 (like moderately). Among the bread formulations containing GBRF, the one with GBRF prepared after 24 h steeping at pH 3 had a slightly higher (though not significant) overall liking score (6.8). This study demonstrated that it is feasible to substitute wheat flour with up to 30% GBRF in bread formulation without negatively affecting sensory acceptance. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 30% germinated brown rice flour in a wheat bread formulation without negatively affecting sensory acceptance. In the current United States market, this type of bread may be sold as frozen bread which would have a longer shelf life. Further study is thus needed.

  1. Primary vesicles, vesicle-rich segregation structures and recognition of primary and secondary porosities in lava flows from the Paraná igneous province, southern Brazil

    Science.gov (United States)

    Barreto, Carla Joana S.; de Lima, Evandro F.; Goldberg, Karin

    2017-04-01

    This study focuses on a volcanic succession of pāhoehoe to rubbly lavas of the Paraná-Etendeka Province exposed in a single road profile in southernmost Brazil. This work provides an integrated approach for examining primary vesicles and vesicle-rich segregation structures at the mesoscopic scale. In addition, this study provides a quantitative analysis of pore types in thin section. We documented distinct distribution patterns of vesicle and vesicle-rich segregation structures according to lava thickness. In compound pāhoehoe lavas, the cooling allows only vesicles (pipe vesicles to be frozen into place. In inflated pāhoehoe lavas, vesicles of different sizes are common, including pipe vesicles, and also segregation structures such as proto-cylinders, cylinders, cylinder sheets, vesicle sheets, and pods. In rubbly lavas, only vesicles of varying sizes occur. Gas release from melt caused the formation of primary porosity, while hydrothermal alteration and tectonic fracturing are the main processes that generated secondary porosity. Although several forms of porosity were created in the basaltic lava flows, the precipitation of secondary minerals within the pores has tended to reduce the original porosities. Late-stage fractures could create efficient channel networks for possible hydrocarbon/groundwater migration and entrapment owing to their ability to connect single pores. Quantitative permeability data should be gathered in future studies to confirm the potential of these lavas for store hydrocarbons or groundwater.

  2. Effect of Different Germination Conditions on Antioxidative Properties and Bioactive Compounds of Germinated Brown Rice

    Directory of Open Access Journals (Sweden)

    You-Tung Lin

    2015-01-01

    Full Text Available This study investigates antioxidative activity and bioactive compounds of ungerminated brown rice (UBR and germinated brown rice (GBR. We used two rice cultivars (Oryza sativa L., Taiwan Japonica 9 (TJ-9 and Taichung Indica 10 (TCI-10, as the materials in our experiments. The conditions for inducing germination are soaking time in water 24, 48, or 72 h; temperature 26 or 36°C; incubation in light or darkness; and open or closed vessels, in which the antioxidative activities and bioactive compounds of GBR were determined. We found that, in order to maximize antioxidative activity and bioactive compounds, germination should be under higher temperature (36°C, long soaking time (72 h, darkness, and closed vessel. GBR contains much higher levels of antioxidative activity and bioactive compounds than ungerminated brown rice (UBR. We found a strong correlation between antioxidative activities (DPPH radical scavenging ability, reducing power, and Trolox equivalent antioxidant capacity and bioactive compounds (γ-oryzanols, tocopherol, and tocotrienol. Higher temperature (36°C is also conducive to the production of GABA in GBR. These results are considered very useful research references for the development of future functional foods and additives.

  3. Evolution of nutrient ingredients in tartary buckwheat seeds during germination.

    Science.gov (United States)

    Yiming, Zhou; Hong, Wang; Linlin, Cui; Xiaoli, Zhou; Wen, Tang; Xinli, Song

    2015-11-01

    Evolution of nutrient components and the antioxidative activity of seed sprouts of tartary buckwheat (Fagopyrum tataricum L. Gaertn) were investigated in the course of germination. Results showed that the contents of total flavonoids increased with germination time and leveled off after the third germination day with the changing trend of rutin and quercetin opposite to each other. The decrease of total protein and total sugar contents in the germinated seeds was accompanied respectively by an increase of amino acid and reducing sugar contents. The contents of vitamin C (Vc) and B1(V(B1)) exhibited a minimum with no appreciable changes found for vitamin B(2) (V(B2)) and B(6) (V(B6)). The contents of total chlorophyll, chlorophyll A and B all exhibited a maximum on the fifth germination day. The contents of fatty acids had no regular changing trend with germination time. The free radical-scavenging activities of the seeds increased with germination time and were caused by an increase in their antioxidative activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Ecophysiology of seed germination in Digitaria insularis ((L. Fedde

    Directory of Open Access Journals (Sweden)

    Giovana Soares de Mendonça

    Full Text Available The invasive behaviour of sourgrass (Digitaria insularis in cultivated areas is due to its strategy of aggressive regeneration, which is based on seed germination. Knowledge of the physiological ecology of this species can contribute to the development of management and control strategies. The aim of this research was to understand the effects of provenance, temperature and light on the germination of sourgrass seeds collected in the Brazilian state of São Paulo in the cities of Americana, Botucatu and São José do Rio Preto and in the state of Paraná in the city of São Miguel do Iguaçu. The seeds were left to germinate at temperatures of 15, 25, 35 and 45 °C, both with and without light. The number of normal seedlings was recorded daily from seven to 60 days. After this period, the seeds together with substrate, were transferred to 25 ºC with light, and a daily count was made for all treatments until the end of germination (75 days after sowing. The seeds of D. insularis are positively photoblastic. Seed germination in this species depends on provenance. A temperature of 4 5 °C for germination is lethal to the seeds. The temperature of 35 °C in the presence of light is the most favourable condition for seed germination.

  5. [Study on conditions of seed germination of Cistanche].

    Science.gov (United States)

    Qiao, Xue-Yi; Wang, Hua-Lei; Guo, Yu-Hai

    2007-09-01

    To study the effect of fluridone concentration, stimulating period, temperature and salt on the seed germination of three species of Cistanche. The seeds were cultured in Petri dish, and the germination percentage was counted. The highest germination percentage was observed in Cistanche tubulosa, C. deserticola, C. sala seeds pre-treated by 0.1 mg x L(-1) fluridone for 24-29 h. The optimal temperature for the seeds germination of three species of Cistanche was at 20-30 degrees C, and the seeds did not germinate at sub-or supraoptimal temperatures (5 and 35 degrees C). The salt tolerance of C. sala seeds was strong, and the critical value of NaCl concentration was 0.04 mol x L(-1). By contrast, C. tubulosa and C. deserticola seeds were more sensitive to the salt stress, the critical value of NaCl concentration was 0.02 mol x L(-1). The optimal germination condition and the method of testing germination percentage of three species of Cistanche seeds are as follow: the seeds are pre-treated by 0.1 mg x L(-1) fluridone for 24 h and then cultured at 20-30 degrees C in salt solution which concentration is lower than 0.02 mol x L(-1).

  6. [Study on physiological and germination characteristics of Tulipa edulis seed].

    Science.gov (United States)

    Wu, Zhengjun; Zhu, Zaibiao; Guo, Qiaosheng; Ma, Hongliang; Xu, Hongjian; Miao, Yuanyuan

    2012-03-01

    Current study was conducted to investigate the seed physiological characteristics of Tulipa edulis and improve germination rate. Anatomical characteristics was observed. Seed water absorption curve was tested by soaking method. Dynamic of embryo development and germination rate as well as germination index under different conditions were recorded. And the biological test of cabbage seed was used for detecting the germination inhibitors. The embryo rate of newly matured seeds was about 10%, and there was no obstacle of water absorption on testa of T. edulis. The optimum method for embryo development was exposure to 300 mg x L(-1) gibberellin solution for 24 hours, and stratification at 25 degrees C for 70 days followed by stratification at 5 degrees C for 40 days. The germintion rate and germination index of dormancy-broken seeds under the dark environment at 10 degrees C and 15 degrees C were significantly higher than those under other conditions. Additionally, there were some germination inhibitory substances in dry seeds. The seed of T. edulis can be classified as having complex morphophysiological dormancy, and the morphological embryo dormancy played a leading role. Warm and cold stratification resulted in a fast dormancy breaking effect, and a high germination rate more than 90% could be obtained under the optimum conditions.

  7. Optimization of jenipapo in vitro seed germination process

    Directory of Open Access Journals (Sweden)

    Rafaela Ribeiro de Souza

    Full Text Available ABSTRACT The in vitro seed germination is an effective alternative for quickly obtaining explants with sanitary quality. However, jenipapo seeds present slow and uneven germination. Therefore, internal and external factors to seed which directly interfere in the process, they must be identified, in order to adapt better techniques to obtain seedlings. In this sense, this work aimed to optimize the in vitro germination of Genipa americana L. seeds by evaluating different factors (light quality, GA3 treatment, pre-soaking in distilled water, growing media and stratification in the dark. It was found that the seed germination of G. americana was indifferent to light, however, the best results were obtained under conditions of continuous darkness; There was no effect of the application of exogenous GA3; The pre-soaking in distilled water for 48 h contributes to obtaining better germination rates; And the reduction in MS medium salts, and laminating the pretreatment in the dark maximizes the germination potential of seeds.Therefore, the optimal conditions for in vitro germination of G. americana L. seeds requires pre-soaking in distilled water for 48 hours and inoculation into culture media consisting of 1/2 MS + 15 g L-1 sucrose, with stratification in the dark for 16 days, followed by the transfer to growth chambers with lighting provided by white fluorescent lamps.

  8. Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Kevin Peter [Univ. of Rochester, NY (United States)

    1978-01-01

    Light (30 to 32.5% sucrose) and heavy (38.5 to 42% sucrose) sarcoplasmic reticulum vesicles (LSR, HSR) were isolated from rabbit leg muscle. They were then diluted and washed with sucrose or KCl and referred to as sucrose or KCl washed vesicles. Thin-section electron microscopy of LSR vesicles reveals empty vesicles of various sizes and shapes where as the HSR vesicles appear as rounded vesicles of uniform size filled with electron dense material. The LSR consists of predominantly Ca2+ + Mg2+ ATPase (80 to 90%), a small amount of the high affinity Ca binding protein (5%), and a 5000 dalton proteolipid. The sucrose HSR vesicles contain the Ca2+ + Mg2+ ATPase (50%), Calsequestrin (25%), high affinity Ca binding protein (5%), one extrinsic 34,000 dalton protein (3%), one intrinsic 30,000 dalton protein (3%), a 9000 dalton proteolipid, and a 5000 dalton proteolipid. The sucrose--washed HSR vesicles contain greater than three times the calcium content of the sucrose washed LSR vesicles where as the KCl--washed vesicles contain less than 15 nmoles Ca2+ mg of protein each. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP. Exchange of methanesulfonate for chloride resulted in the release of calcium from both the light and heavy SR vesicles. Sucrose causes a slight inhibition of chloride--induced calcium release from the heavy SR vesicles but it greatly reduces the release of calcium from the light SR vesicles. Sodium dantrolene (20 uM) has no effect on the release of calcium from the light SR vesicles but it inhibits the release of calcium from the heavy SR vesicles. The results indicate that the chloride--induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization.

  9. Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles. Volume I

    International Nuclear Information System (INIS)

    Campbell, K.P.

    1978-01-01

    Light (30 to 32.5% sucrose) and heavy (38.5 to 42% sucrose) sarcoplasmic reticulum vesicles (LSR, HSR) were isolated from rabbit leg muscle. They were then diluted and washed with sucrose or KCl and referred to as sucrose or KCl washed vesicles. Thin-section electron microscopy of LSR vesicles reveals empty vesicles of various sizes and shapes where as the HSR vesicles appear as rounded vesicles of uniform size filled with electron dense material. The LSR consists of predominantly Ca 2+ + Mg 2+ ATPase (80 to 90%), a small amount of the high affinity Ca binding protein (5%), and a 5000 dalton proteolipid. The sucrose HSR vesicles contain the Ca 2+ + Mg 2+ ATPase (50%), Calsequestrin (25%), high affinity Ca binding protein (5%), one extrinsic 34,000 dalton protein (3%), one intrinsic 30,000 dalton protein (3%), a 9000 dalton proteolipid, and a 5000 dalton proteolipid. The sucrose--washed HSR vesicles contain greater than three times the calcium content of the sucrose washed LSR vesicles where as the KCl--washed vesicles contain less than 15 nmoles Ca 2+ /mg of protein each. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP. Exchange of methanesulfonate for chloride resulted in the release of calcium from both the light and heavy SR vesicles. Sucrose causes a slight inhibition of chloride--induced calcium release from the heavy SR vesicles but it greatly reduces the release of calcium from the light SR vesicles. Sodium dantrolene (20 uM) has no effect on the release of calcium from the light SR vesicles but it inhibits the release of calcium from the heavy SR vesicles. The results indicate that the chloride--induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization

  10. MRI, CT and TRUS imaging of seminal vesicle metastasis

    International Nuclear Information System (INIS)

    Larsson, P.; Blomqvist, L.; Norming, U.

    1997-01-01

    We present a case of a testicular germ-cell metastasis in the seminal vesicle. Diagnostic imaging with transrectal ultrasonography (TRUS), CT, and MRI was performed. This case emphasizes the role of MRI in the evaluation of patients with pathology in the pelvic region. (orig.)

  11. Glycosylation of extracellular vesicles : current knowledge, tools and clinical perspectives

    NARCIS (Netherlands)

    Williams, Charles; Royo, Felix; Aizpurua-Olaizola, Oier; Pazos, Raquel; Boons, Geert-Jan; Reichardt, Niels-Christian; Falcon-Perez, Juan M

    2018-01-01

    It is now acknowledged that extracellular vesicles (EVs) are important effectors in a vast number of biological processes through intercellular transfer of biomolecules. Increasing research efforts in the EV field have yielded an appreciation for the potential role of glycans in EV function. Indeed,

  12. Continuous fabrication of polymeric vesicles and nanotubes with fluidic channe

    NARCIS (Netherlands)

    Peng, F.; Deng, N.-N.; Tu, Y.; van Hest, J.C.M.; Wilson, D.A.

    2017-01-01

    Fluidic channels were employed to induce the self-assembly of poly(ethylene glycol)-b-polystyrene into polymeric vesicles and nanotubes. The laminar flow in the device enables controlled diffusion of two miscible liquids at the phase boundary, leading to the formation of homogeneous polymeric

  13. Primary malignancy of seminal vesicle: A rare entity

    Directory of Open Access Journals (Sweden)

    Rajaraman Ramamurthy

    2011-01-01

    Full Text Available We report a rare case of seminal vesicle malignancy (primitive neuro ectodermal tumor in a 40-year-old male patient. He was treated with enbloc resection of the tumor and ureteric reimplantation. In view of the rarity of this entity, management of these tumors should be individualized.

  14. Seminal vesicle abscess causing unilateral hydroureteronephrosis: A case report

    Directory of Open Access Journals (Sweden)

    Vittorio Imperatore

    2017-12-01

    Full Text Available Seminal vesicle abscess (SVA is a rare urologic entity. It mainly occurs in subjects with predisposing factors and may be associated with other urogenital infections. We describe the case of a diabetic subject with SVA associated with funiculitis, epididymitis and obstructive pyelonephritis. Treatment consisted of laparotomic surgical drainage of the abscess and ureteral stent placement.

  15. A Pathogenic Potential of Acinetobacter baumannii-Derived Membrane Vesicles

    Directory of Open Access Journals (Sweden)

    Jong Suk Jin

    2011-12-01

    Full Text Available Acinetobacter baumannii secretes outer membrane vesicles (OMVs. A. baumannii OMVs deliver many virulence factors to host cells and then induce cytotoxicity and innate immune response. OMVs secreted from bacteria contribute directly to host pathology during A. baumannii infection.

  16. Penetration and fusion of phospholipid vesicles by lysozyme

    International Nuclear Information System (INIS)

    Kim, J.; Kim, H.

    1989-01-01

    The lysozyme-induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles as studied at a wide range of pH is found to correlate well with the binding of this protein to the vesicles. An identical 6000 molecular weight segment of lysozyme at the N-terminal region is found to be protected from tryptic digestion when initially incubated with vesicles at several pH values. Only this segment is labeled by dansyl chloride, which is partitioned into the bilayer. These results suggest the penetration of one segment of lysozyme into the bilayer. Photoactivated labeling of the membrane-penetrating segment of lysozyme with 3-(trifluoromethyl)-3-([ 125 I]iodophenyl)diazirine ([ 125 I]TID) and subsequent identification of the labeled residues by Edman degradation and gamma-ray counting indicate that four amino acids from the N-terminal are located outside the hydrophobic core of the bilayer. Although treatment of the membrane-embedded segment with aminopeptidase failed to cleave any amino acids from the N-terminal, it appears that a loop of lysozyme segment near the N-terminal penetrates into the bilayer at acidic pH. A helical wheel diagram shows that the labeling is done mainly on one surface of the alpha-helix. The penetration kinetics as studied by time-dependent [ 125 I]TID labeling coincide with the fusion kinetics, strongly suggesting that the penetration of the lysozyme segment into the vesicles is the cause of the fusion

  17. Penetration and fusion of phospholipid vesicles by lysozyme

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.; Kim, H. (Korea Advanced Institute of Science and Technology, Seoul)

    1989-10-01

    The lysozyme-induced fusion of phosphatidylserine/phosphatidylethanolamine vesicles as studied at a wide range of pH is found to correlate well with the binding of this protein to the vesicles. An identical 6000 molecular weight segment of lysozyme at the N-terminal region is found to be protected from tryptic digestion when initially incubated with vesicles at several pH values. Only this segment is labeled by dansyl chloride, which is partitioned into the bilayer. These results suggest the penetration of one segment of lysozyme into the bilayer. Photoactivated labeling of the membrane-penetrating segment of lysozyme with 3-(trifluoromethyl)-3-(({sup 125}I)iodophenyl)diazirine (({sup 125}I)TID) and subsequent identification of the labeled residues by Edman degradation and gamma-ray counting indicate that four amino acids from the N-terminal are located outside the hydrophobic core of the bilayer. Although treatment of the membrane-embedded segment with aminopeptidase failed to cleave any amino acids from the N-terminal, it appears that a loop of lysozyme segment near the N-terminal penetrates into the bilayer at acidic pH. A helical wheel diagram shows that the labeling is done mainly on one surface of the alpha-helix. The penetration kinetics as studied by time-dependent ({sup 125}I)TID labeling coincide with the fusion kinetics, strongly suggesting that the penetration of the lysozyme segment into the vesicles is the cause of the fusion.

  18. Removal of Vesicle Structures from Transmission Electron Microscope Images

    DEFF Research Database (Denmark)

    Jensen, Katrine Hommelhoff; Sigworth, Fred; Brandt, Sami Sebastian

    2015-01-01

    In this paper, we address the problem of imaging membrane proteins for single-particle cryo-electron microscopy reconstruction of the isolated protein structure. More precisely, we propose a method for learning and removing the interfering vesicle signals from the micrograph, prior to reconstruct...

  19. Sortilin mediates vascular calcification via its recruitment into extracellular vesicles

    DEFF Research Database (Denmark)

    Goettsch, Claudia; Hutscheson, JD; Aikawa, M

    2016-01-01

    obscure. Here, we have demonstrated that sortilin is a key regulator of smooth muscle cell (SMC) calcification via its recruitment to extracellular vesicles. Sortilin localized to calcifying vessels in human and mouse atheromata and participated in formation of microcalcifications in SMC culture. Sortilin...

  20. Ultrasound-guided seminal vesicle biopsies in prostate cancer

    NARCIS (Netherlands)

    Wymenga, LFA; Duisterwinkel, FJ; Groenier, K; Mensink, HJA

    2000-01-01

    Invasion of prostatic adenocarcinoma into the seminal vesicles (SV) is generally accepted as an index of poor prognosis. The pre-operative identification of SV invasion is an important element in staging since it may alter subsequent treatment decisions. We studied the possibility of diagnosing SV

  1. Transcutol containing vesicles for topical delivery of minoxidil.

    Science.gov (United States)

    Mura, Simona; Manconi, Maria; Valenti, Donatella; Sinico, Chiara; Vila, Amparo Ofelia; Fadda, Anna Maria

    2011-04-01

    The aim of this work was to evaluate the ability of Transcutol (Trc) to produce elastic vesicles with soy lecithin (SL) and study the influence of the obtained vesicles on in vitro (trans)dermal delivery of minoxidil. To this purpose, so-called penetration enhancer-containing vesicles (PEVs) were prepared using Trc aqueous solutions (5-10-20-30% v/v) as hydrophilic phase. SL liposomes, without Trc, were used as control. Prepared formulations were characterized in terms of size distribution, morphology, zeta potential, deformability, and rheological behavior. The influence of the obtained PEVs on (trans)dermal delivery of minoxidil was studied by in vitro diffusion experiments through pig skin. Results showed that all prepared PEVs were able to give good entrapment efficiency (E%≈67) similar to that of conventional liposomes. Trc-containing PEVs showed to be more deformable than liposomes only when minoxidil was loaded in 5 and 10% Trc-containing vesicles. Rheological studies showed that PEVs have higher fluidity than conventional liposomes. All PEVs showed a higher stability than liposomes as shown by studying zeta potential and size distribution during three months. Results of in vitro diffusion experiments showed that Trc-containing PEVs are able to deliver minoxidil to deep skin layers without any transdermal permeation.

  2. Transmembrane topology of the acetylcholine receptor examined in reconstituted vesicles

    International Nuclear Information System (INIS)

    McCrea, P.D.

    1987-01-01

    Each of the five acetylcholine receptor (AChR) subunits, α 2 β-γδ, is believed to have the same number of transmembrane crossing and to share the same general folding pattern. AChR isolated from the electric organ of electric fish is predominantly dimeric. We have used this bridge as a marker for the C-terminus of the δ subunit, and presumably that of the other subunits in addition. The disulfide's accessibility to hydrophilic reductants, principally glutathione (GSH), was tested in a reconstituted vesicle system. The reduction of the δ-δ desulfide, as evidenced by the transition of AChrR dimers to monomers, was quantitatively monitored on velocity sedimentation sucrose gradients. Alternatively, the reduction of δ 2 to δ was followed by employing non-reducing SDS-PAGE. Reductants such as GSH were able to access the bridge in intact right-side-out vesicles. No acceleration of this process was evident when the vesicles were disrupted by freeze-thaw or by detergents. Control experiments which determined the rate of reduction of entrapped diphtheria toxin, or that of 3 H-GSH efflux, demonstrated that intact reconstituted vesicles provide an adequate permeability barrier to GSH access of their intravesicular space

  3. Inflammation leads to distinct populations of extracellular vesicles from microglia

    DEFF Research Database (Denmark)

    Yang, Yiyi; Boza-Serrano, Antonio; Dunning, Christopher J.R.

    2018-01-01

    Background: Activated microglia play an essential role in inflammatory responses elicited in the central nervous system (CNS). Microglia-derived extracellular vesicles (EVs) are suggested to be involved in propagation of inflammatory signals and in the modulation of cell-to-cell communication...

  4. Intermedin inhibits norepinephrine-induced contraction of rat seminal vesicle

    Directory of Open Access Journals (Sweden)

    P.F. Wong

    2014-09-01

    Conclusion: The results demonstrated that the inhibitory action of IMD on NE-induced seminal vesicle contraction was mediated via the ADM receptor(s and the nitric oxide production pathway, partially by the IMD receptor, but not by the CGRP receptor and the cAMP-PKA pathway.

  5. Calcium transport in vesicles energized by cytochrome oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Rosier, Randy N. [Univ. of Rochester, NY (United States)

    1979-01-01

    Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K+ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K+ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

  6. Thermally assisted acoustofluidic separation of extracellular vesicles from cells

    Science.gov (United States)

    Mirtaheri, Elnaz; Dolatmoradi, Ata; Pimentel, Krystine; Bhansali, Shekhar; El-Zahab, Bilal

    2018-02-01

    Extracellular vesicles (EVs) have been gaining increasing attention given their role in communicating information between cells. Composition-based isolation of EVs is particularly of high significance as the proteomic and lipidomic characterization of their cargo could provide valuable clues to the role of EVs in mediating the biology of various conditions. This has, however, proved to be challenging as EVs, despite their abundance, are very small and difficult to be differentiated from the other constituents of host media. In addition, currently available methods like ultracentrifugation and filtration are cumbersome and capable of achieving mostly size-based separations. In this work, we demonstrate the possibility of separating submicron EV-like vesicles from cancer cells using a thermally-assisted acoustophoretic device. In a system composed of MCF-7 breast cancer cells spiked with two different types of same-size vesicles, composition-based isolation of vesicles was shown to be realizable through opposite focusing of the system's components at the node and antinodes of the overlaid ultrasonic standing wave. By proper choice of temperature in the microchannel, we were able to achieve separations with purities exceeding 93%. Furthermore, cells recovered from the channel were shown to be viable after the separation.

  7. Thin film drainage between pre-inflated capsules or vesicles

    Science.gov (United States)

    Keh, Martin; Walter, Johann; Leal, Gary

    2013-11-01

    Capsules and vesicles are often used as vehicles to carry active ingredients or fragrance in drug delivery and consumer products and oftentimes in these applications the particles may be pre-inflated due to the existence of a small osmotic pressure difference between the interior and exterior fluid. We study the dynamics of thin film drainage between capsules and vesicles in flow as it is crucial to fusion and deposition of the particles and, therefore, the stability and effectiveness of the products. Simulations are conducted using a numerical model coupling the boundary integral method for the motion of the fluids and a finite element method for the membrane mechanics. For low capillary numbers, the drainage behavior of vesicles and capsules are approximately the same, and also similar to that of drops as the flow-independent and uniform tension due to pre-inflation dominates. The tension due to deformation caused by flow will become more important as the strength of the external flow (i.e. the capillary number) increases. In this case, the shapes of the thin film region are fundamentally different for capsules and vesicles, and the drainage behavior in both cases differs from a drop. Funded by P&G.

  8. Brivaracetam augments short-term depression and slows vesicle recycling.

    Science.gov (United States)

    Yang, Xiaofeng; Bognar, Joseph; He, Tianyu; Mohammed, Mouhari; Niespodziany, Isabelle; Wolff, Christian; Esguerra, Manuel; Rothman, Steven M; Dubinsky, Janet M

    2015-12-01

    Brivaracetam (BRV) decreases seizure activity in a number of epilepsy models and binds to the synaptic vesicle glycoprotein 2A (SV2A) with a higher affinity than the antiepileptic drug levetiracetam (LEV). Experiments were performed to determine if BRV acted similarly to LEV to induce or augment short-term depression (STD) under high-frequency neuronal stimulation and slow synaptic vesicle recycling. Electrophysiologic field excitatory postsynaptic potential (fEPSP) recordings were made from CA1 synapses in rat hippocampal slices loaded with BRV or LEV during intrinsic activity or with BRV actively loaded during hypertonic stimulation. STD was examined in response to 5 or 40 Hz stimulus trains. Presynaptic release of FM1-43 was visualized using two-photon microscopy to assess drug effects upon synaptic vesicle mobilization. When hippocampal slices were incubated in 0.1-30 μm BRV or 30 μm-1 mm LEV for 3 h, the relative CA1 field EPSPs decreased over the course of a high-frequency train of stimuli more than for control slices. This STD was frequency- and concentration-dependent, with BRV being 100-fold more potent than LEV. The extent of STD depended on the length of the incubation time for both drugs. Pretreatment with LEV occluded the effects of BRV. Repeated hypertonic sucrose treatments and train stimulation successfully unloaded BRV from recycling vesicles and reversed BRVs effects on STD, as previously reported for LEV. At their maximal concentrations, BRV slowed FM1-43 release to a greater extent than in slices loaded with LEV during prolonged stimulation. BRV, similar to LEV, entered into recycling synaptic vesicles and produced a frequency-dependent decrement of synaptic transmission at 100-fold lower concentrations than LEV. In addition, BRV slowed synaptic vesicle mobilization more effectively than LEV, suggesting that these drugs may modify multiple functions of the synaptic vesicle protein SV2A to curb synaptic transmission and limit epileptic activity

  9. Germination and seedling establishment in orchids: a complex of requirements.

    Science.gov (United States)

    Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara

    2015-09-01

    Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several

  10. Germination rate is the significant characteristic determining coconut palm diversity.

    Science.gov (United States)

    Harries, Hugh C

    2012-01-01

    This review comes at a time when in vitro embryo culture techniques are being adopted for the safe exchange and cryo-conservation of coconut germplasm. In due course, laboratory procedures may replace the options that exist among standard commercial nursery germination techniques. These, in their turn, have supplanted traditional methods that are now forgotten or misunderstood. Knowledge of all germination options should help to ensure the safe regeneration of conserved material. This review outlines the many options for commercial propagation, recognizes the full significance of one particular traditional method and suggests that the diversity of modern cultivated coconut varieties has arisen because natural selection and domestic selection were associated with different rates of germination and other morphologically recognizable phenotypic characteristics. The review takes into account both the recalcitrant and the viviparous nature of the coconut. The ripe fruits that fall but do not germinate immediately and lose viability if dried for storage are contrasted with the bunches of fruit retained in the crown of the palm that may, in certain circumstances, germinate to produce seedlings high above ground level. Slow-germinating and quick-germinating coconuts have different patterns of distribution. The former predominate on tropical islands and coastlines that could be reached by floating when natural dispersal originally spread coconuts widely-but only where tides and currents were favourable-and then only to sea-level locations. Human settlers disseminated the domestic types even more widely-to otherwise inaccessible coastal sites not reached by floating-and particularly to inland and upland locations on large islands and continental land masses. This review suggests four regions where diversity has been determined by germination rates. Although recent DNA studies support these distinctions, further analyses of genetic markers related to fruit abscission and

  11. Germination traits of three weed species in Kosovo

    Directory of Open Access Journals (Sweden)

    A. Mehmeti

    2010-02-01

    Full Text Available Amaranthus retroflexus, Echinochloa crus-galli and Datura stramonium are the most important weed species in Kosovo. They cause severe yield depression, contaminate fodder and negatively affect growth and reproduction of other weed species. To counteract these problems, specific strategies need to be developed. Such strategies should consider information on species germination traits. In this context, our study provides information on temperature requirements for germination. Seeds of A. retroflexus, E. crus-galli and D. stramonium were harvested in two sub-regions of Kosovo (western and eastern parts differing in climate and land use. They were set for germination experiments in growth chambers at temperatures ranging from 3 to 35 °C and under field conditions. In both experiments, the germination rate differed between species and provenances. In the growth chamber experiment, germination of all three species was negligible below 15 °C and reached the highest rates between 24 and 30 °C. Seeds originating from the western part of Kosovo had higher germination rates and required a lower temperature for germination than seeds originating from the eastern part. In the field experiment, the time-dependent germination behaviour of D. stramonium differed between provenances. In general, germination started when soil temperature was above 18 °C and continued as long as the soil was moist. The results are discussed in the context of the need to develop weed management strategies against these weeds in Kosovo.

  12. Germination rate is the significant characteristic determining coconut palm diversity

    Science.gov (United States)

    Harries, Hugh C.

    2012-01-01

    Rationale This review comes at a time when in vitro embryo culture techniques are being adopted for the safe exchange and cryo-conservation of coconut germplasm. In due course, laboratory procedures may replace the options that exist among standard commercial nursery germination techniques. These, in their turn, have supplanted traditional methods that are now forgotten or misunderstood. Knowledge of all germination options should help to ensure the safe regeneration of conserved material. Scope This review outlines the many options for commercial propagation, recognizes the full significance of one particular traditional method and suggests that the diversity of modern cultivated coconut varieties has arisen because natural selection and domestic selection were associated with different rates of germination and other morphologically recognizable phenotypic characteristics. The review takes into account both the recalcitrant and the viviparous nature of the coconut. The ripe fruits that fall but do not germinate immediately and lose viability if dried for storage are contrasted with the bunches of fruit retained in the crown of the palm that may, in certain circumstances, germinate to produce seedlings high above ground level. Significance Slow-germinating and quick-germinating coconuts have different patterns of distribution. The former predominate on tropical islands and coastlines that could be reached by floating when natural dispersal originally spread coconuts widely—but only where tides and currents were favourable—and then only to sea-level locations. Human settlers disseminated the domestic types even more widely—to otherwise inaccessible coastal sites not reached by floating—and particularly to inland and upland locations on large islands and continental land masses. This review suggests four regions where diversity has been determined by germination rates. Although recent DNA studies support these distinctions, further analyses of genetic markers

  13. Pseudomonas aeruginosa vesicles associate with and are internalized by human lung epithelial cells

    Directory of Open Access Journals (Sweden)

    Kuehn Meta J

    2009-02-01

    Full Text Available Abstract Background Pseudomonas aeruginosa is the major pathogen associated with chronic and ultimately fatal lung infections in patients with cystic fibrosis (CF. To investigate how P. aeruginosa-derived vesicles may contribute to lung disease, we explored their ability to associate with human lung cells. Results Purified vesicles associated with lung cells and were internalized in a time- and dose-dependent manner. Vesicles from a CF isolate exhibited a 3- to 4-fold greater association with lung cells than vesicles from the lab strain PAO1. Vesicle internalization was temperature-dependent and was inhibited by hypertonic sucrose and cyclodextrins. Surface-bound vesicles rarely colocalized with clathrin. Internalized vesicles colocalized with the endoplasmic reticulum (ER marker, TRAPα, as well as with ER-localized pools of cholera toxin and transferrin. CF isolates of P. aeruginosa abundantly secrete PaAP (PA2939, an aminopeptidase that associates with the surface of vesicles. Vesicles from a PaAP knockout strain exhibited a 40% decrease in cell association. Likewise, vesicles from PAO1 overexpressing PaAP displayed a significant increase in cell association. Conclusion These data reveal that PaAP promotes the association of vesicles with lung cells. Taken together, these results suggest that P. aeruginosa vesicles can interact with and be internalized by lung epithelial cells and contribute to the inflammatory response during infection.

  14. Molecular Recognition of Vesicles : Host-Guest Interactions Combined with Specific Dimerization of Zwitterions

    NARCIS (Netherlands)

    Voskuhl, Jens; Fenske, Tassilo; Stuart, Marc C. A.; Wibbeling, Birgit; Schmuck, Carsten; Ravoo, Bart Jan

    2010-01-01

    The aggregation of beta-cyclodextrin vesicles can be induced by an adamantyl-substituted zwitterionic guanidiniocarbonylpyrrole carboxylate guest molecule (1). Upon addition of 1 to the cyclodextrin vesicles at neutral pH, the vesicles aggregate (but do not fuse), as shown by using UV/Vis and

  15. Pulsed-laser polymerization in compartmentalized liquids. 1. Polymerization in vesicles

    NARCIS (Netherlands)

    Jung, M.; Casteren, van I.A.; Monteiro, M.J.; Herk, van A.M.; German, A.L.

    2000-01-01

    Polymerization in vesicles is a novel type of polymerization in heterogeneous media, leading to parachute-like vesicle-polymer hybrid morphologies. To explore the kinetics of vesicle polymerizations and to learn more about the actual locus of polymerization we applied the pulsed-laser polymerization

  16. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  17. Seminal vesicle metastasis after partial hepatectomy for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Gong, Li; Zheng, Minwen; Li, Yanhong; Zhang, Wendong; Bu, Wangjun; Shi, Lifang; Zhang, Wei; Yan, Hong

    2011-01-01

    Metastasis to the seminal vesicle is extremely rare for hepatocellular carcinoma (HCC). To our knowledge, it has been not reported in literature. The purpose of the present paper was to report a case of metastasis to the seminal vesicle after HCC resection, along with its histological features and immunohistochemical characteristics. A 46-year-old Chinese man was admitted to our hospital due to abdominal distension. He had a history of HCC related to hepatitis B virus infection. Moreover, left partial hepatectomy was performed in another hospital 28 months ago, and right partial hepatectomy for HCC recurrence in our hospital 4 months ago. After resection, radiofrequency ablation therapy had been performed. About 27 months after the initial operation, contrast-enhanced computed tomography (CT) of the pelvic cavity revealed a mass with homogeneous enhancement in the seminal vesicle. Transrectal needle biopsy revealed a poorly differentiated adenocarcinoma. Therefore, seminal vesiculectomy was resected. The histological diagnosis of the removed tumor was compatible with the original HCC. Immunohistochemical examination demonstrated that the tumor cells were positive for glypican-3 (GPC3), alpha-fetoprotein (AFP), hepatocyte paraffin-1 (Hep Par 1), cytokeratin 18 (CK 18), and hepatocyte antigen, which confirmed that the seminal vesicle tumor was a metastatic tumor of HCC. However, CT subsequently revealed multiple metastatic foci in the abdominal and pelvic cavities in May 2009 and August 2009, respectively. The seminal vesicle is an extremely rare metastatic site for HCC, and the prognosis is very poor. A combination of clinical and pathological features is necessary for a correct diagnosis, and primary tumor should be excluded before diagnosing metastatic foci

  18. Production and germination of Tussilago farfara (L. diaspores

    Directory of Open Access Journals (Sweden)

    Anna Namur-Ochocka

    2014-01-01

    Full Text Available In the paper the production of generative diaspores in Tussilago farfara (L. was assessed in four different ecological systems. Also their morphological characteristics, as well as their germinability under natural and laboratory conditions were analysed, depending upon the age, density and size of diaspores, as well as sowing depth, substrate type and light conditions. The studies showed that diaspores: 1 were highly germinable under laboratory conditions; 2 did not germinate effectively under natural conditions; 31 were short-lived; 4 were tolerant to unfavourable habitat agents. Tussilago farfara was determined to exhibit high diaspore production only under conditions of suppresed interspecific competition.

  19. Elemental variations in the germinating fungus Phytophthora palmivora

    International Nuclear Information System (INIS)

    Mazzolini, A.P.; Sealock, R.M.; Legge, G.J.F.; Grant, B.R.

    1991-01-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn. (orig.)

  20. Elemental variations in the germinating fungus Phytophthora palmivora

    Science.gov (United States)

    Mazzolini, A. P.; Grant, B. R.; Sealock, R. M.; Legge, G. J. F.

    1991-03-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn.

  1. Germination and development of pecan cultivar seedlings by seed stratification

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate the effect of seed stratification on germination rate, germination speed, and initial development of seedlings of six pecan (Carya illinoinensis cultivars under subtropical climatic conditions in southern Brazil. For stratification, the seeds were placed in boxes with moist sand, in a cold chamber at 4°C, for 90 days. In the fourteenth week after sowing, the emergence speed index, total emergence, plant height, stem diameter, and number of leaves were evaluated. Seed stratification significantly improves the germination potential and morphological traits of the evaluated cultivars.

  2. Effects of seed pretreatment and seed source on germination of five ...

    African Journals Online (AJOL)

    The effects of seed pre-sowing treatment and geographic source of seeds on three germination parameters of five Acacia species (GP = germination percent; GMT = germination mean time (days) and GI = germination index) were studied. Pre-sowing treatment included immersion in concentrated sulphuric acid for 5, 10 and ...

  3. 7 CFR 201.29 - Germination of vegetable seed in containers of 1 pound or less.

    Science.gov (United States)

    2010-01-01

    ... the percentage of germination and date of test. Each variety of vegetable seed which has a germination... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination of vegetable seed in containers of 1 pound... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.29 Germination of...

  4. Elastic vesicles for transdermal drug delivery of hydrophilic drugs: a comparison of important physicochemical characteristics of different vesicle types.

    Science.gov (United States)

    Ntimenou, Vassiliki; Fahr, Alfred; Antimisiaris, Sophia G

    2012-08-01

    The aim of this study is to evaluate the influence of different lipid vesicular systems on the skin permeation ability of hydrophilic molecules, and understand if and which vesicle physicochemical properties may be used as predictive tools. Calcein and carboxyfluorescein were used as hydrophilic drug models. All vesicles (conventional liposomes [CLs], transfersomes [TRs] and invasomes [INVs]), were characterized for particle size distribution, zeta-potential, vesicular shape and morphology, encapsulation efficiency, integrity, colloidal stability, elasticity and finally in vitro human skin permeation. Dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM) defined that almost all vesicles had spherical structure, low polydispersity (PI Elasticity values (measured by extrusion through membranes) were in the order INVs > TRs > CLs. Three vesicle types were selected (having different elasticity) and in vitro skin permeation experiments demonstrated that calcein permeation was minimal from an aqueous solution, slightly enhanced from CLs, and enhanced by 1.8 and 7.2 times from TRs and INVs, respectively. Permeation and elasticity values were correlated by rank order but not linearly, indicating that elasticity can be used as a crude predictive tool for enhancement of skin transport. Drug encapsulation efficiency was not found to be an important factor in the current study.

  5. [Effects of illumination and seed-soaking reagent on seed germination of Solanum nigrum].

    Science.gov (United States)

    Yang, Chuan-Jie; Wei, Shu-He; Zhou, Qi-Xing; Hu, Ya-Hu; Niu, Rong-Cheng

    2009-05-01

    To explore a rapid seed germination method for hyperaccumulator Solanum nigrum, a germination experiment with different illumination and seed-soaking treatments was conducted in constant temperature box and greenhouse, with filter as burgeon base. Under illumination, the germination rate was about 5 times high of that without illumination (P seed germination of S. nigrum. All test seed-soaking reagents could significantly improve the germination rate of S. nigrum (P seeds treated with H2O2 had the shortest germination time. The germination rate of seeds soaked but without cleaning was 2-3 times as high as that of seeds soaked and cleaned with water.

  6. Flow Friction or Spontaneous Ignition?

    Science.gov (United States)

    Stoltzfus, Joel M.; Gallus, Timothy D.; Sparks, Kyle

    2012-01-01

    "Flow friction," a proposed ignition mechanism in oxygen systems, has proved elusive in attempts at experimental verification. In this paper, the literature regarding flow friction is reviewed and the experimental verification attempts are briefly discussed. Another ignition mechanism, a form of spontaneous combustion, is proposed as an explanation for at least some of the fire events that have been attributed to flow friction in the literature. In addition, the results of a failure analysis performed at NASA Johnson Space Center White Sands Test Facility are presented, and the observations indicate that spontaneous combustion was the most likely cause of the fire in this 2000 psig (14 MPa) oxygen-enriched system.

  7. Spontaneous rupture of vaginal enterocele

    DEFF Research Database (Denmark)

    Svendsen, J H; Galatius, H; Hansen, P K

    1985-01-01

    Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission.......Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission....

  8. Spontaneous baryogenesis from asymmetric inflaton

    International Nuclear Information System (INIS)

    Takahashi, Fuminobu

    2015-10-01

    We propose a variant scenario of spontaneous baryogenesis from asymmetric inflaton based on current-current interactions between the inflaton and matter fields with a non-zero B-L charge. When the inflaton starts to oscillate around the minimum after inflation, it may lead to excitation of a CP-odd component, which induces an effective chemical potential for the B-L number through the current-current interactions. We study concrete inflation models and show that the spontaneous baryogenesis scenario can be naturally implemented in the chaotic inflation in supergravity.

  9. Minimal experimental requirements for definition of extracellular vesicles and their functions: a position statement from the International Society for Extracellular Vesicles.

    Science.gov (United States)

    Lötvall, Jan; Hill, Andrew F; Hochberg, Fred; Buzás, Edit I; Di Vizio, Dolores; Gardiner, Christopher; Gho, Yong Song; Kurochkin, Igor V; Mathivanan, Suresh; Quesenberry, Peter; Sahoo, Susmita; Tahara, Hidetoshi; Wauben, Marca H; Witwer, Kenneth W; Théry, Clotilde

    2014-01-01

    Secreted membrane-enclosed vesicles, collectively called extracellular vesicles (EVs), which include exosomes, ectosomes, microvesicles, microparticles, apoptotic bodies and other EV subsets, encompass a very rapidly growing scientific field in biology and medicine. Importantly, it is currently technically challenging to obtain a totally pure EV fraction free from non-vesicular components for functional studies, and therefore there is a need to establish guidelines for analyses of these vesicles and reporting of scientific studies on EV biology. Here, the International Society for Extracellular Vesicles (ISEV) provides researchers with a minimal set of biochemical, biophysical and functional standards that should be used to attribute any specific biological cargo or functions to EVs.

  10. Constant and alternating temperature effects on germination and early growth of scorzonera

    OpenAIRE

    Dias, A.S.; Dias, L.S.; Pereira, I.P.

    2013-01-01

    Scorzonera is a threatened species in Portugal. Given the role of temperature in germination and seedling recruitment, the performance of total germination, lag of germination, duration of germination, shape of germination, root and hypocotyl length, and relative root growth of scorzonera was investigated under constant and alternating temperatures between 10 and 25ºC. Because of scorzonera’s rarity and threatened status, seeds of cultivated scorzonera were used, providing the framework for h...

  11. Variation of germination of eggplant (Solanum melongena L.) seed during storage life

    OpenAIRE

    Ristić, Nevena; Todorović, Vesna; Adžić, Slađan; Zdravković, Jasmina

    2013-01-01

    Eggplant (Solanum melongena L.) seed is dormant, which means that the maximum germination is achieved after some time. The research was performed on one genotype (Domaci srednje dugi - DSD). The seed, studied for germination rate, originates from year 2007 and the germination variation was studied for period 2007 - 2011. Eggplant seed was dormant after yield in 2007, but the germination increased over the years. The trial was conducted at the standard germination test method, defined in the R...

  12. pre-germination treatments in castor seeds, cultivar IAC 226

    International Nuclear Information System (INIS)

    Costa Nobre, Danubia Aparecida; Gomes Damascena, Joyce; Marcia, Andreia; Santos de Souza, David; Pereira dos Santos, Marlucia; Rodrigues Pereira, Adriana; Goncalves Pereira, Cassio

    2013-01-01

    The present study aimed to evaluate the efficiency of different pre-germination treatments in castor beans, IAC 226. The experimental design was completely randomized in a factorial 4 x 4 (four temperatures and four immersion times), with four replications. Pre-germination treatments were: immersion in water at room temperature (25 Celsius degrade) and immersion in hot water at temperatures of 60, 70 and 80 Celsius degrade for 2, 4, 6 and 8 minutes. Water content of the seeds was determined before treatments. Before and after each treatment, seeds were subjected to germination test; 20-30 Celsius degrade alternating temperature, determining the percentages of normal and abnormal seedlings, dormant and dead seeds. Independent of time, immersion in 70 Celsius degrade, water was the most efficient treatment for accelerating germination of castor bean cultivar IAC 226.

  13. Germination and in vitro multiplication of Helianthemum kahiricum, a ...

    African Journals Online (AJOL)

    aghomotsegin

    2015-03-25

    Mar 25, 2015 ... Seeds of Helianthemum kahiricum have an excellent germination rate ... of H. kahiricum on Murashige and Skoog medium (MS) free growth regulators ... The kinetin had a positive effect on the multiplication and growth, but a.

  14. Germination and In Vitro Regeneration Response of Local Nigerian ...

    African Journals Online (AJOL)

    Prof. Ogunji

    the highest germination percentage of 57.33% and percentage contamination of. 11.11% ... development of in vitro regeneration of the crop from various explant sources. The advent of ..... Effect of variety and plant growth regulators on callus.

  15. A germination test: an easy approach to know the irradiation

    International Nuclear Information System (INIS)

    Khawar, A.; Bhatti, I.A.; Bhatti, H.N.

    2010-01-01

    Food irradiation is an evolving preserving technique that provides a shield against the spoilage and might have a potential to ensure the food safety and security world wide. In the present study, feasibility to apply germination test to distinguish an un-irradiated and irradiated samples of wheat, maize, chickpea and black eye beans was checked. Samples were irradiated to the absorbed doses ranging from 0-10 kGy using Co-60 gamma irradiator and were germinated in plant growth chamber. Root and shoot lengths were measured at 7th day after gamma radiation treatment. In all the irradiated samples root and shoot lengths were decreased with the increase in radiation absorbed doses. The seeds irradiated to the absorbed doses more than 2 kGy were not germinated. Germination test proved as an easy and simple method to detect irradiation in wheat, maize, chickpea and black eye beans irradiated even at low absorbed doses. (author)

  16. Effects of salinity stress on water uptake, germination and early ...

    African Journals Online (AJOL)

    Administrator

    2011-09-07

    Sep 7, 2011 ... Department of Field Crops, Faculty of Agriculture, Namik Kemal University, 59100 Tekirdag, ..... stresses on germination in durum wheat (Triticum durum Desf.) .... transgenic perennial ryegrass (Lolium perenne L.) obtained by.

  17. In vitro pollen quantity, viability and germination tests in quince

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees ..... their pollen characteristics to be used in cross breeding ... viability and germination levels for pistachio and terebinth in.

  18. In vitro pollen germination of five citrus species

    International Nuclear Information System (INIS)

    Khan, S.A.; Perveen, A.

    2014-01-01

    The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

  19. Effects of different NaCl Concentrations on germination and ...

    African Journals Online (AJOL)

    USER

    Salinity refers to the salt content of any given system. By nature, arid .... Effect of varying concentrations of NaCl on seed germination of Amaranthus hybridus in percentages. .... Osmotic differences could explain this phenomenon where by ...

  20. The effect of osmopriming on germination, seedling growth and ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... affecting the oxidative metabolism such as increasing superoxide dismutase ... the adverse effect of salinity by improving germination and seedling growth .... osmoregulation by the accumulation of proline. A positive effect of ...

  1. Germination, growth and nodulation of Trigonella foenum graecum ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... In this work, we analyzed the effects of salinity on seed germination, growth and nodulation of fenugreek ..... metabolic activities in function, such as the accumulation .... stress: possible role of trehalose in osmoregulation. Lett.

  2. Desiccation effects on germination and vigor of King palm seeds

    Directory of Open Access Journals (Sweden)

    Martins Cibele C.

    2003-01-01

    Full Text Available The desiccation tolerance of Archontophoenix alexandrae (Wendl. & Drude seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. Mature fruits were harvested in the palm collection of the Instituto Agronomico in Campinas, Brazil. Depulped fruits were transported in impermeable packages to the Faculdade de Agronomia in Botucatu, where the seeds were dried. As the seed moisture decreased, germination, seedling length, electrical conductivity and moisture were measured. The seeds of A. alexandrae are recalcitrant, with high germination percentage (over 67% when undried (47% seed moisture. Lowering seed moisture below 31.5% reduced the germination rate significantly (<52.5%. Total germination failure was observed when seed moisture reached 15.1%. The electrical conductivity was the most sensitive vigor test to identify seed deterioration.

  3. Germination of Chenopodium Album in Response to Microwave Plasma Treatment

    International Nuclear Information System (INIS)

    Sera, Bozena; Stranak, Vitezslav; Sery, Michal; Spatenka, Petr; Tichy, Milan

    2008-01-01

    The seeds of Lamb's Quarters (Chenopodium album agg.) were stimulated by low-pressure discharge. The tested seeds were exposed to plasma discharge for different time durations (from 6 minutes to 48 minutes). Germination tests were performed under specified laboratory conditions during seven days in five identical and completely independent experiments. Significant differences between the control and plasma-treated seeds were observed. The treated seeds showed structural changes on the surface of the seat coat. They germinated faster and their sprout accretion on the first day of seed germination was longer. Germination rate for the untreated seeds was 15% while it increased approximately three times (max 55%) for seeds treated by plasma from 12 minutes to 48 minutes.

  4. inhibition of germination and growth behavior of some cowpea

    African Journals Online (AJOL)

    DR. AMIN

    2011-12-02

    Dec 2, 2011 ... COWPEA VARIETIES USING NEEM (AZADIRACTA INDICA) LEAF WATER. EXTRACTS ... Keywords: Neem, Allelopathic effect, Leaf extract, Germination, Growth behavior ... and lotion today, as well as biological insecticide.

  5. Germination Response of Gum Arabic (Acacia senegal L.) Seeds to ...

    African Journals Online (AJOL)

    ... Arabic (Acacia senegal L.) Seeds to Hot Water Pre-Treatment in Maiduguri, ... of Maiduguri under tree shade, to study the effect of hot water pre-treatment duration. ... Germination response, pre-sowing treatment, gum Arabic, orthodox seeds.

  6. Effects of animal's rumen juice on seed germination of Vicia ...

    African Journals Online (AJOL)

    DR TONUKARI NYEROVWO

    2011-08-22

    Aug 22, 2011 ... To help understand the effects of grazing on seed germination characteristics of Vicia angustifolia L., we conducted a ... feed forage seeds or reproduction organs selectively and changes the ... The mean daily air temperature ...

  7. Effects of Seed Size on Germination and Early Morphorlogical and ...

    African Journals Online (AJOL)

    Effects of Seed Size on Germination and Early Morphorlogical and Physiological Characteristics of Gmelina Arborea , Roxb. ... African Research Review ... They were grouped into 3 categories as large seed size (LSS), medium seed size ...

  8. The plasma membrane proteome of germinating barley embryos

    DEFF Research Database (Denmark)

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.

    2009-01-01

    Cereal seed germination involves a complex coordination between different seed tissues. Plasma membranes must play crucial roles in coordination and execution of germination; however, very little is known about seed plasma membrane proteomes due to limited tissue amounts combined...... with amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol...... was used to reduce soluble protein contamination and enrich for hydrophobic proteins. Sixty-one proteins in 14 SDS-PAGE bands were identified by LC-MS/MS and database searches. The identifications provide new insight into the plasma membrane functions in seed germination....

  9. Comparison of seed priming techniques with regards to germination ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-11-16

    Nov 16, 2016 ... investigate the effects of different priming techniques on seed germination and early seedling growth. The seeds ... methods in which the environment must be controlled for prolonged ..... Guanabara Koogan, Rio de Janeiro ...

  10. Focus on Extracellular Vesicles: Therapeutic Potential of Stem Cell-Derived Extracellular Vesicles

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2016-02-01

    Full Text Available The intense research focus on stem and progenitor cells could be attributed to their differentiation potential to generate new cells to replace diseased or lost cells in many highly intractable degenerative diseases, such as Alzheimer disease, multiple sclerosis, and heart diseases. However, experimental and clinical studies have increasingly attributed the therapeutic efficacy of these cells to their secretion. While stem and progenitor cells secreted many therapeutic molecules, none of these molecules singly or in combination could recapitulate the functional effects of stem cell transplantations. Recently, it was reported that extracellular vesicles (EVs could recapitulate the therapeutic effects of stem cell transplantation. Based on the observations reported thus far, the prevailing hypothesis is that stem cell EVs exert their therapeutic effects by transferring biologically active molecules such as proteins, lipids, mRNA, and microRNA from the stem cells to injured or diseased cells. In this respect, stem cell EVs are similar to EVs from other cell types. They are both primarily vehicles for intercellular communication. Therefore, the differentiating factor is likely due to the composition of their cargo. The cargo of EVs from different cell types are known to include a common set of proteins and also proteins that reflect the cell source of the EVs and the physiological or pathological state of the cell source. Hence, elucidation of the stem cell EV cargo would provide an insight into the multiple physiological or biochemical changes necessary to affect the many reported stem cell-based therapeutic outcomes in a variety of experimental models and clinical trials.

  11. Genetically controlled fusion, exocytosis and fission of artificial vesicles-a roadmap

    DEFF Research Database (Denmark)

    Bönzli, Eva; Hadorn, Maik; de Lucrezia, Davide

    2011-01-01

    were shown to fuse if a special class of viral proteins, termed fusogenic peptides, were added to the external medium (Nomura et al. 2004). In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we...... enclosed synthesized peptides in vesicles to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different...

  12. A VESICLE TRAFFICKING PROTEIN αSNAP REGULATES PANETH CELL DIFFERENTIATION IN VIVO

    Science.gov (United States)

    Lechuga, Susana; Naydenov, Nayden G.; Feygin, Alex; Jimenez, Antonio J.; Ivanov, Andrei I.

    2017-01-01

    A soluble N-ethylmaleimide-sensitive factor-attachment protein alpha (αSNAP) is a multifunctional scaffolding protein that regulates intracellular vesicle trafficking and signaling. In cultured intestinal epithelial cells, αSNAP has been shown to be essential for cell survival, motility, and adhesion; however, its physiologic functions in the intestinal mucosa remain unknown. In the present study, we used a mouse with a spontaneous hydrocephalus with hop gait (hyh) mutation of αSNAP to examine the roles of this trafficking protein in regulating intestinal epithelial homeostasis in vivo. Homozygous hyh mice demonstrated decreased expression of αSNAP protein in the intestinal epithelium, but did not display gross abnormalities of epithelial architecture in the colon and ileum. Such αSNAP depletion attenuated differentiation of small intestinal epithelial enteroids ex vivo. Furthermore, αSNAP-deficient mutant animals displayed reduced formation of lysozyme granules in small intestinal crypts and decreased expression of lysozyme and defensins in the intestinal mucosa, which is indicative of defects in Paneth cell differentiation. By contrast, development of Goblet cells, enteroendocrine cells, and assembly of enterocyte apical junctions was not altered in hyh mutant mice. Our data revealed a novel role of αSNAP in the intestinal Paneth cell differentiation in vivo. PMID:28359759

  13. A vesicle trafficking protein αSNAP regulates Paneth cell differentiation in vivo.

    Science.gov (United States)

    Lechuga, Susana; Naydenov, Nayden G; Feygin, Alex; Jimenez, Antonio J; Ivanov, Andrei I

    2017-05-13

    A soluble N-ethylmaleimide-sensitive factor-attachment protein alpha (αSNAP) is a multifunctional scaffolding protein that regulates intracellular vesicle trafficking and signaling. In cultured intestinal epithelial cells, αSNAP has been shown to be essential for cell survival, motility, and adhesion; however, its physiologic functions in the intestinal mucosa remain unknown. In the present study, we used a mouse with a spontaneous hydrocephalus with hop gait (hyh) mutation of αSNAP to examine the roles of this trafficking protein in regulating intestinal epithelial homeostasis in vivo. Homozygous hyh mice demonstrated decreased expression of αSNAP protein in the intestinal epithelium, but did not display gross abnormalities of epithelial architecture in the colon and ileum. Such αSNAP depletion attenuated differentiation of small intestinal epithelial enteroids ex vivo. Furthermore, αSNAP-deficient mutant animals displayed reduced formation of lysozyme granules in small intestinal crypts and decreased expression of lysozyme and defensins in the intestinal mucosa, which is indicative of defects in Paneth cell differentiation. By contrast, development of Goblet cells, enteroendocrine cells, and assembly of enterocyte apical junctions was not altered in hyh mutant mice. Our data revealed a novel role of αSNAP in the intestinal Paneth cell differentiation in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Buffer-induced swelling and vesicle budding in binary lipid mixtures of dioleoylphosphatidylcholine:dioleoylphosphatidylethanolamine and dioleoylphosphatidylcholine:lysophosphatidylcholine using small-angle X-ray scattering and ³¹P static NMR.

    Science.gov (United States)

    Barriga, Hanna M G; Bazin, Richard; Templer, Richard H; Law, Robert V; Ces, Oscar

    2015-03-17

    A large variety of data exists on lipid phase behavior; however, it is mostly in nonbuffered systems over nonbiological temperature ranges. We present biophysical data on lipid mixtures of dioleoylphosphatidylcholine (DOPC), dioleoylphosphatidylethanolamine (DOPE), and lysophosphatidylcholine (LysoPC) examining their behaviors in excess water and buffer systems over the temperature range 4-34 °C. These mixtures are commonly used to investigate the effects of spontaneous curvature on integral membrane proteins. Using small-angle X-ray scattering (SAXS) and (31)P NMR, we observed lamellar and vesicle phases, with the buffer causing an increase in the layer spacing. Increasing amounts of DOPE in a DOPC bilayer decreased the layer spacing of the mesophase, while the opposite trend was observed for increasing amounts of LysoPC. (31)P static NMR was used to analyze the DOPC:LysoPC samples to investigate the vesicle sizes present, with evidence of vesicle budding observed at LysoPC concentrations above 30 mol %. NMR line shapes were fitted using an adapted program accounting for the distortion of the lipids within the magnetic field. The distortion of the vesicle, because of magnetic susceptibility, varied with LysoPC content, and a discontinuity was found in both the water and buffer samples. Generally, the distortion increased with LysoPC content; however, at a ratio of DOPC:LysoPC 60:40, the sample showed a level of distortion of the vesicle similar to that of pure DOPC. This implies an increased flexibility in the membrane at this point. Commonly, the assumption is that for increasing LysoPC concentration there is a reduction in membrane tension, implying that estimations of membrane tension based on spontaneous curvature assumptions may not be accurate.

  15. Ecophysiology of seed germination in Digitaria insularis ((L.) Fedde)

    OpenAIRE

    Mendonça,Giovana Soares de; Martins,Cibele Chalita; Martins,Dagoberto; Costa,Neumárcio Vilanova da

    2014-01-01

    The invasive behaviour of sourgrass (Digitaria insularis) in cultivated areas is due to its strategy of aggressive regeneration, which is based on seed germination. Knowledge of the physiological ecology of this species can contribute to the development of management and control strategies. The aim of this research was to understand the effects of provenance, temperature and light on the germination of sourgrass seeds collected in the Brazilian state of São Paulo in the cities of Americana, B...

  16. Memorandum on the effect of ozone on germinating seeds

    Energy Technology Data Exchange (ETDEWEB)

    Micheels, H; De Heen, P

    1906-01-01

    Two experiments are described the purpose of which was to ascertain the effect of ozone on germinating plants. In both experiments the plants which were not exposed to ozone had considerably longer roots and greater average weight. The number of germinations was not affected in one experiment, but was down 10% in the other. A final comment suggests that although the toxicity of ozone is well known, its use as a stimulant should not be ruled out. 2 figures.

  17. Seed and Germination Characteristics of 20 Amazonian Liana Species

    Directory of Open Access Journals (Sweden)

    Mareike Roeder

    2013-01-01

    Full Text Available Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches.

  18. Effect of Estrogen and Progeterone on seed germination

    Directory of Open Access Journals (Sweden)

    Nirmala

    Full Text Available Early pregnancy detection in dairy cattle is an integral part of a successful animal husbandry practice. A simple seed germination technique (Punyakoti test comprises observation of differential seed germination response of wheat seeds to diluted fresh urine samples as reflected by significant inhibition of germination percentage in pregnant cow urine when compared to non pregnant cow urine. Hormone metabolites excreted through urine might affect the seed germination in pregnant cow urine. In the present study an attempt was made to test the effect of hormones (in their natural forms at different concentrations of estrogen (17-ß estradiol and progesterone on wheat and green gram germination. Stock solutions of estrogen and progesterone were prepared in alcohol (1mg/ml and serial dilutions made using distilled water to get the concentrations of T1=10, T2=1, T3=0.1 and T4=0.01 μg/ml respectively in treatment groups. About 15 seeds each of wheat and green gram were taken in sterile Petri dishes into which 15ml of each test preparation was poured. The treatments were compared with distilled water and alcohol controls. The study was conducted for a period of five days during which seed germination was observed after 48 hrs and shoot lengths were also measured by the end of study. The average seed germination and shoot length in treatment groups did not vary significantly (P>0.05 when compared with that of control groups. Thus from the present study, it can be concluded that estrogen and progesterone in their natural form will not affect seed germination and shoot length. [Veterinary World 2008; 1(8.000: 241-242

  19. Constant temperatures and the rate of seed germination in maize ...

    African Journals Online (AJOL)

    The rate of germination of the NEM cultivar was faster than that of the QPM cultivar at all temperatures. The thermal times for median germination were 46 for QPM and 40.7 oCd for the NEM cultivar. The cardinal temperatures (base, Tb, optimum, To and ceiling, Tc) for the NEM cultivar were Tb: 7, To: 30 and Tc: 48.2 oC.

  20. Detection of association and fusion of giant vesicles using a fluorescence-activated cell sorter.

    Science.gov (United States)

    Sunami, Takeshi; Caschera, Filippo; Morita, Yuuki; Toyota, Taro; Nishimura, Kazuya; Matsuura, Tomoaki; Suzuki, Hiroaki; Hanczyc, Martin M; Yomo, Tetsuya

    2010-10-05

    We have developed a method to evaluate the fusion process of giant vesicles using a fluorescence-activated cell sorter (FACS). Three fluorescent markers and FACS technology were used to evaluate the extent of association and fusion of giant vesicles. Two fluorescent markers encapsulated in different vesicle populations were used as association markers; when these vesicles associate, the two independent markers should be observed simultaneously in a single detection event. The quenched fluorescent marker and the dequencher, which were encapsulated in separate vesicle populations, were used as the fusion marker. When the internal aqueous solutions mix, the quenched marker is liberated by the dequencher and emits the third fluorescent signal. Although populations of pure POPC vesicles showed no detectable association or fusion, the same populations, oppositely charged by the exogenous addition of charged amphiphiles, showed up to 50% association and 30% fusion upon population analysis of 100,000 giant vesicles. Although a substantial fraction of the vesicles associated in response to a small amount of the charged amphiphiles (5% mole fraction compared to POPC alone), a larger amount of the charged amphiphiles (25%) was needed to induce vesicle fusion. The present methodology also revealed that the association and fusion of giant vesicles was dependent on size, with larger giant vesicles associating and fusing more frequently.

  1. Fusion of Sendai virus with vesicles of oligomerizable lipids: a microcalorimetric analysis of membrane fusion.

    Science.gov (United States)

    Ravoo, B J; Weringa, W D; Engberts, J B

    2000-01-01

    Sendai virus fuses efficiently with small and large unilamellar vesicles of the lipid 1,2-di-n-hexadecyloxypropyl-4- (beta-nitrostyryl) phosphate (DHPBNS) at pH 7.4 and 37 degrees C, as shown by lipid mixing assays and electron microscopy. However, fusion is strongly inhibited by oligomerization of the head groups of DHPBNS in the bilayer vesicles. The enthalpy associated with fusion of Sendai virus with DHPBNS vesicles was measured by isothermal titration microcalorimetry, comparing titrations of Sendai virus into (i) solutions of DHPBNS vesicles (which fuse with the virus) and (ii) oligomerized DHPBNS vesicles (which do not fuse with the virus), respectively. The observed heat effect of fusion of Sendai virus with DHPBNS vesicles is strongly dependent on the buffer medium, reflecting a partial charge neutralization of the Sendai F and HN proteins upon insertion into the negatively-charged vesicle membrane. No buffer effect was observed for the titration of Sendai virus into oligomerized DHPBNS vesicles, indicating that inhibition of fusion is a result of inhibition of insertion of the fusion protein into the target membrane. Fusion of Sendai virus with DHPBNS vesicles is endothermic and entropy-driven. The positive enthalpy term is dominated by heat effects resulting from merging of the protein-rich viral envelope with the lipid vesicle bilayers rather than by the fusion of the viral with the vesicle bilayers per se. Copyright 2000 Academic Press.

  2. Attachment of 99mTc to lipid vesicles containing the lipophilic chelate dipalmitoylphosphatidylethanolamine-DTPA

    International Nuclear Information System (INIS)

    Ahkong, Q.F.; Tilcock, C.

    1992-01-01

    The binding of 99m Tc to negatively-charged and neutral unilamellar lipid vesicles was investigated in the absence and presence of the ligand diethylenetriaminepentaacetic acid (DTPA) covalently attached to the headgroup of phosphatidylethanolamine at the surface of the membrane. Even in the absence of DTPA on the membrane surface, 99m Tc reduced by Sn bound to the membrane surface but rapidly dissociated from the vesicles in the presence of plasma in vitro. When DTPA was present on the membrane surface, dissociation of 99m Tc from the vesicle surface in plasma was much reduced. The dissociation of 99m Tc from the surface of negatively-charged vesicles was less than for neutral vesicles in the absence of ligand but was markedly greater than for vesicles containing the ligand DTPA, suggesting that the binding of 99m Tc to vesicles with surface-attached DTPA could not be explained solely on the basis of the negative charge provided by the DTPA. In vitro experiments using 14 C-labeled lipids as well as in vivo imaging studies indicated that dissociation of 99m Tc from the surface of the vesicle did not arise predominantly because of lipid exchange with plasma components or due to cleavage of Tc-DTPA from the vesicle surface. For vesicles with surface-attached DTPA, 99m Tc dissociation from the vesicle surface in plasma was further reduced by addition of the antioxidant ascorbate. (author)

  3. Ca2+-dependent mobility of vesicles capturing anti-VGLUT1 antibodies

    International Nuclear Information System (INIS)

    Stenovec, Matjaz; Kreft, Marko; Grilc, Sonja; Potokar, Maja; Kreft, Mateja Erdani; Pangrsic, Tina; Zorec, Robert

    2007-01-01

    Several aspects of secretory vesicle cycle have been studied in the past, but vesicle trafficking in relation to the fusion site is less well understood. In particular, the mobility of recaptured vesicles that traffic back toward the central cytoplasm is still poorly defined. We exposed astrocytes to antibodies against the vesicular glutamate transporter 1 (VGLUT1), a marker of glutamatergic vesicles, to fluorescently label vesicles undergoing Ca 2+ -dependent exocytosis and examined their number, fluorescence intensity, and mobility by confocal microscopy. In nonstimulated cells, immunolabeling revealed discrete fluorescent puncta, indicating that VGLUT1 vesicles, which are approximately 50 nm in diameter, cycle slowly between the plasma membrane and the cytoplasm. When the cytosolic Ca 2+ level was raised with ionomycin, the number and fluorescence intensity of the puncta increased, likely because the VGLUT1 epitopes were more accessible to the extracellularly applied antibodies following Ca 2+ -triggered exocytosis. In nonstimulated cells, the mobility of labeled vesicles was limited. In stimulated cells, many vesicles exhibited directional mobility that was abolished by cytoskeleton-disrupting agents, indicating dependence on intact cytoskeleton. Our findings show that postfusion vesicle mobility is regulated and may likely play a role in synaptic vesicle cycle, and also more generally in the genesis and removal of endocytic vesicles

  4. Mechanism of fluridone-induced seed germination of cistanche tubulosa

    International Nuclear Information System (INIS)

    Chen, Q.L.; Tu, P.

    2016-01-01

    Our previous study disclosed that fluridone, a synthesis inhibitor of abscisic acid (ABA), could stimulate seed germination in the holoparasitic plant Cistanche tubulosa . Nonetheless, the underlying mechanisms have not been thoroughly elucidated. In the present study, an attempt was made to reveal the mechanism of fluridone breaking seed dormancy in C. tubulosa and to determine the contribution of hormones in this process. The ABA level in seeds initially decreased following fluridone treatment and was subsequently maintained at a concentration of 31 ng g/sup -1/ DW (dry weight) three days later. The contents of gibberellins (GAs) initially in creased and subsequently were maintained at a level of 40 ng g-1 DW after ten days. However, the increment of seed germination induced by fluridone was inhibited after the introduction of exogenous ABA or paclobutrazol (a synthesis inhibitor of GAs). Furthermore, inhibition from paclobutrazol was reversed by an additional treatment with exogenous GA3. When the ratio of endogenous GAs to ABA reached 4:3, C. tubulosa seeds initiated germination. By contrast, although the ratio of endogenous GAs to ABA content reached 2:1 by cold stratification, C. tubulosa seeds could not germinate unless exogenous GA3 was added. In summary, our current study revealed that (i) GAs and ABA play key roles for the seed germination of C. tubulosa , (ii) fluridone inhibited ABA biosynthesis but increased the concentration of GAs in seeds, and (iii) fluridone might initiate other processes associated with germination. (author)

  5. Temperature Effects on Cuscuta campestris Yunk. Seed Germination

    Directory of Open Access Journals (Sweden)

    Marija Sarić-Krsmanović

    2013-01-01

    Full Text Available Studies of biological characteristics of seeds and conditions for their germination havea major importance for planning and executing rational measures of weed control. Theaim of this study was to investigate the effect of different temperatures on germinationof C. campestris seeds. Three treatments (T1- storage at room temperature; T2 – exposureto 4°C for 30 days; T3 – scarification by concentrated sulphuric acid differing in manipulationwith seeds before germination were tested at different temperatures (5°C, 10°C, 15°C,20°C, 25°C, 30°C, 35°C, 40°C, 45°C. Germinated seeds were counted daily for ten days andthe length of seedlings was measured on the last day. The results showed that differencesin germination of C. campestris seeds were very prominent between temperatures, as wellas between treatments T1, T2 and T3. Seeds failed to germinate at 5°C and 45°C in all treatments(T1, T2, T3. Germination ranged from 6.25 at 10°C to 96.88%, the highest percentage,achieved at 30°C.

  6. TIME REDUCTION FOR SURINAM GRASS SEED GERMINATION TEST

    Directory of Open Access Journals (Sweden)

    Camila de Aquino Tomaz

    2015-10-01

    Full Text Available ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.

  7. Omethoate treatment mitigates high salt stress inhibited maize seed germination.

    Science.gov (United States)

    Yang, Kejun; Zhang, Yifei; Zhu, Lianhua; Li, Zuotong; Deng, Benliang

    2018-01-01

    Omethoate (OM) is a highly toxic organophophate insecticide, which is resistant to biodegradation in the environment and is widely used for pest control in agriculture. The effect of OM on maize seed germination was evaluated under salt stress. Salt (800mM) greatly reduced germination of maize seed and this could be reversed by OM. Additionally, H 2 O 2 treatment further improved the effect of OM on seed germination. Higher H 2 O 2 content was measured in OM treated seed compared to those with salt stress alone. Dimethylthiourea (DTMU), a specific scavenger of reactive oxygen species (ROS), inhibited the effect of OM on seed germination, as did IMZ (imidazole), an inhibitor of NADPH oxidase. Abscisic acid (ABA) inhibited the effect of OM on seed germination, whereas fluridone, a specific inhibitor of ABA biosynthesis, enhanced the effect of OM. Taken together, these findings suggest a role of ROS and ABA in the promotion of maize seed germination by OM under salt stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Effect of germination and thermal treatments on folates in rye.

    Science.gov (United States)

    Kariluoto, Susanna; Liukkonen, Kirsi-Helena; Myllymäki, Olavi; Vahteristo, Liisa; Kaukovirta-Norja, Anu; Piironen, Vieno

    2006-12-13

    Effects of germination conditions and thermal processes on folate contents of rye were investigated. Total folate contents were determined microbiologically with Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism, and individual folates were determined by high-performance liquid chromatography after affinity chromatographic purification. Germination increased the folate content by 1.7-3.8-fold, depending on germination temperature, with a maximum content of 250 micro g/100 g dry matter. Hypocotylar roots with their notably high folate concentrations (600-1180 micro g/100 g dry matter) contributed 30-50% of the folate contents of germinated grains. Germination altered the proportions of folates, increasing the proportion of 5-methyltetrahydrofolate and decreasing the proportion of formylated folate compounds. Thermal treatments (extrusion, autoclaving and puffing, and IR and toasting) resulted in significant folate losses. However, folate levels in grains that were germinated and then were heat processed were higher than for native (nongerminated) grains. Opportunities to optimize rye processing to enhance folate levels in rye-based foods are discussed.

  9. The biological role of exogenic factors in broomrape germination

    International Nuclear Information System (INIS)

    Zhelev, N.

    1987-01-01

    The often observed contradictory effect of the substances stimulating broomrape seed germination were assessed and explained. Low and optimal concentrations of these substances had a stimulating effect, while the high concentrations produced an inhibiting effect. For chemically pure mustard oil, phenylisothiocianate and allylisothiocianate such concentrations are 10 -4 to 10 -3 and more. The effectiveness of substances stimulating germination is conditioned in many cases by their watersoluble or gaseous state. The latter state of the stimulating substances is more natural, more economic and more efficient for the fumigation (in low concentrations) of the soil layer penetrated by the roots where parasitic seeds are present. A considerable number of agricultural crops, releasing by their roots essential oils containing glucosides, the hydrolysis of which results in elimination of volatile products of mustard oil type, represent natural stimulators for the germination of broomrape seeds. The effect of gamma-ray irradiation of parasitic seeds depends on their state. Dry seeds endure 80-120 krad, while moist ones - only 40-80 krad. Broomrape (O. ramosa and O. mutella) seeds begin their germination at 10 grad C. The optimal temperature for germination is 18-30 grad C, while 35-40 grad C irreversively discontinues the germination

  10. A study of the enhanced sensitizing capacity of a contact allergen in lipid vesicle formulations

    DEFF Research Database (Denmark)

    Simonsson, Carl; Madsen, Jakob Torp; Graneli, Annette

    2011-01-01

    , an indicator of a compounds sensitizing capacity, increased when RBITC was applied in lipid vesicles as compared to an ethanol:water (Et:W) solution. Micro-scale vesicles showed a slightly higher cell proliferative response compared to nano-scale vesicles. TPM imaging revealed that the vesicle formulations...... improved the skin penetration of RBITC compared to the Et:W solution. A strong fluorescent region in the stratum corneum and upper epidermis implies elevated association of RBITC to these skin layers when formulated in lipid vesicles. In conclusion, the results indicate that there could be an elevated risk...... of sensitization when haptens are delivered in vehicles containing lipid vesicles. Although the size of the vesicles seems to be of minor importance, further studies are needed before a more generalized conclusion can be drawn. It is likely that the enhanced sensitizing capacity is a consequence of the improved...

  11. Vesicle dynamics in a confined Poiseuille flow: from steady state to chaos.

    Science.gov (United States)

    Aouane, Othmane; Thiébaud, Marine; Benyoussef, Abdelilah; Wagner, Christian; Misbah, Chaouqi

    2014-09-01

    Red blood cells (RBCs) are the major component of blood, and the flow of blood is dictated by that of RBCs. We employ vesicles, which consist of closed bilayer membranes enclosing a fluid, as a model system to study the behavior of RBCs under a confined Poiseuille flow. We extensively explore two main parameters: (i) the degree of confinement of vesicles within the channel and (ii) the flow strength. Rich and complex dynamics for vesicles are revealed, ranging from steady-state shapes (in the form of parachute and slipper shapes) to chaotic dynamics of shape. Chaos occurs through a cascade of multiple periodic oscillations of the vesicle shape. We summarize our results in a phase diagram in the parameter plane (degree of confinement and flow strength). This finding highlights the level of complexity of a flowing vesicle in the small Reynolds number where the flow is laminar in the absence of vesicles and can be rendered turbulent due to elasticity of vesicles.

  12. Lipid vesicle shape analysis from populations using light video microscopy and computer vision.

    Directory of Open Access Journals (Sweden)

    Jernej Zupanc

    Full Text Available We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1-50 µm in diameter. For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness. This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected.

  13. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  14. Spontaneous regression of pulmonary bullae

    International Nuclear Information System (INIS)

    Satoh, H.; Ishikawa, H.; Ohtsuka, M.; Sekizawa, K.

    2002-01-01

    The natural history of pulmonary bullae is often characterized by gradual, progressive enlargement. Spontaneous regression of bullae is, however, very rare. We report a case in which complete resolution of pulmonary bullae in the left upper lung occurred spontaneously. The management of pulmonary bullae is occasionally made difficult because of gradual progressive enlargement associated with abnormal pulmonary function. Some patients have multiple bulla in both lungs and/or have a history of pulmonary emphysema. Others have a giant bulla without emphysematous change in the lungs. Our present case had treated lung cancer with no evidence of local recurrence. He had no emphysematous change in lung function test and had no complaints, although the high resolution CT scan shows evidence of underlying minimal changes of emphysema. Ortin and Gurney presented three cases of spontaneous reduction in size of bulla. Interestingly, one of them had a marked decrease in the size of a bulla in association with thickening of the wall of the bulla, which was observed in our patient. This case we describe is of interest, not only because of the rarity with which regression of pulmonary bulla has been reported in the literature, but also because of the spontaneous improvements in the radiological picture in the absence of overt infection or tumor. Copyright (2002) Blackwell Science Pty Ltd

  15. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  16. Silicosis with bilateral spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Fotedar Sanjay

    2010-01-01

    Full Text Available Presentation with simultaneous bilateral pneumothorax is uncommon and usually in the context of secondary spontaneous pneumothorax.The association of pneumothorax and silicosis is infrequent and most cases are unilateral. Bilateral pneumothorax in silicosis is very rare with just a few reports in medical literature.

  17. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  18. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  19. DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

    OpenAIRE

    Graeber, K.; Linkies, A.; Steinbrecher, T.; Tarkowská, D. (Danuše); Turečková, V. (Veronika); Ignatz, M.; Voegele, A.; Urbanová, T. (Terezie); Strnad, M. (Miroslav); Leubner-Metzger, G. (Gerhard)

    2014-01-01

    Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapp...

  20. La organización germinal

    Directory of Open Access Journals (Sweden)

    Xavier Soca Filella

    2013-08-01

    Full Text Available Las vicisitudes de estos últimos años en las economías occidentales, y sobre todo en las del arco mediterráneo, han sumido las empresas en un profundo callejón sin salida, dónde tras efectuar reducciones drásticas en sus estructuras ahora ven mermadas sus posibilidades de crecimiento. Surge el interrogante de qué tipo de crecimiento perseguimos y qué organización precisamos para conseguirlo. Vislumbramos a partir de lo acaecido en los últimos dos lustros que las organizaciones preferirán moverse dentro de unos patrones de crecimientos sostenibles, en lugar de las alocadas carreras de inicios de siglo. Este crecimiento sostenible comportará decidir que formas de organización permitirán gestionar mejor este crecimiento. Dentro del abanico de las posibilidades, planteo un tipo de organización en constante cambio que facilite la adaptación a los diversos tipos de mercados que puedan ir surgiendo en el futuro: LA ORGANIZACIÓN GERMINAL.

  1. Aminopeptidase Activity from Germinated Jojoba Cotyledons 1

    Science.gov (United States)

    Johnson, Russell; Storey, Richard

    1985-01-01

    One major and two minor aminopeptidase activities from germinated jojoba (Simmondsia chinensis) cotyledon extracts were separated by ammonium sulfate precipitation and chromatofocusing. None of the activities were inhibited by 1,10 phenanthroline. The major aminopeptidase, purified 260-fold, showed a pH optimum of 6.9 with leucine-p-nitroanilide as substrate, a molecular weight estimated at 14,200 by electrophoretic analysis, and an isoelectric point of 4.5 according to the chromatofocusing pattern. Activity was inhibited by p-chloromercuribenzoate, slightly stimulated by 1,10 phenanthroline and 2-mercaptoethanol, and not influenced by Mg2+ or diethyl pyrocarbonate. Inhibition by p-chloromercuribenzoate was prevented by the presence of cysteine in the assay. Leucine-p-nitroanilide and leucine-β-naphthylamide were the most rapidly hydrolyzed of 11 carboxy-terminal end blocked synthetic substrates tested. No activity on endopeptidase or carboxypeptidase specific substrates was detected. The major aminopeptidase showed activity on a saline soluble, jojoba seed protein preparation and we suggest a possible physiological role for the enzyme in the concerted degradation of globulin reserve proteins during cotyledon senescence. PMID:16664465

  2. Aminopeptidase activity from germinated jojoba cotyledons.

    Science.gov (United States)

    Johnson, R; Storey, R

    1985-11-01

    One major and two minor aminopeptidase activities from germinated jojoba (Simmondsia chinensis) cotyledon extracts were separated by ammonium sulfate precipitation and chromatofocusing. None of the activities were inhibited by 1,10 phenanthroline.The major aminopeptidase, purified 260-fold, showed a pH optimum of 6.9 with leucine-p-nitroanilide as substrate, a molecular weight estimated at 14,200 by electrophoretic analysis, and an isoelectric point of 4.5 according to the chromatofocusing pattern. Activity was inhibited by p-chloromercuribenzoate, slightly stimulated by 1,10 phenanthroline and 2-mercaptoethanol, and not influenced by Mg(2+) or diethyl pyrocarbonate. Inhibition by p-chloromercuribenzoate was prevented by the presence of cysteine in the assay. Leucine-p-nitroanilide and leucine-beta-naphthylamide were the most rapidly hydrolyzed of 11 carboxy-terminal end blocked synthetic substrates tested. No activity on endopeptidase or carboxypeptidase specific substrates was detected. The major aminopeptidase showed activity on a saline soluble, jojoba seed protein preparation and we suggest a possible physiological role for the enzyme in the concerted degradation of globulin reserve proteins during cotyledon senescence.

  3. Profiling Gene Expression in Germinating Brassica Roots.

    Science.gov (United States)

    Park, Myoung Ryoul; Wang, Yi-Hong; Hasenstein, Karl H

    2014-01-01

    Based on previously developed solid-phase gene extraction (SPGE) we examined the mRNA profile in primary roots of Brassica rapa seedlings for highly expressed genes like ACT7 (actin7), TUB (tubulin1), UBQ (ubiquitin), and low expressed GLK (glucokinase) during the first day post-germination. The assessment was based on the mRNA load of the SPGE probe of about 2.1 ng. The number of copies of the investigated genes changed spatially along the length of primary roots. The expression level of all genes differed significantly at each sample position. Among the examined genes ACT7 expression was most even along the root. UBQ was highest at the tip and root-shoot junction (RS). TUB and GLK showed a basipetal gradient. The temporal expression of UBQ was highest in the MZ 9 h after primary root emergence and higher than at any other sample position. Expressions of GLK in EZ and RS increased gradually over time. SPGE extraction is the result of oligo-dT and oligo-dA hybridization and the results illustrate that SPGE can be used for gene expression profiling at high spatial and temporal resolution. SPGE needles can be used within two weeks when stored at 4 °C. Our data indicate that gene expression studies that are based on the entire root miss important differences in gene expression that SPGE is able to resolve for example growth adjustments during gravitropism.

  4. Environmental Factors that Interfere in the Germination

    Directory of Open Access Journals (Sweden)

    Lisiane de Souza

    2014-12-01

    Full Text Available This paper refers to the application of experiments with sixth graders of elementary school, aiming motivation, skills development focused on observation, interpersonal relationships in teams, related to the various forms of language skills, as well to identify and resume misconceptions about the external (environmental factors required for seed germination, in order that the contents developed this year refer to the study of the earth, soil, water and air, among others, and that many students do not understand all the concepts and the importance of these factors for the existence of living beings. The experiments were organized in two stages, first to observe the influence of soil and another moment to observe the interference of water, air and light. The temperature impractical activities were conducted, however, during the observation period (three weeks experiments remained in a controlled environment in the science laboratory. For the experiments we used materials easily found in commerce, some recycled; students were organized into six teams, which improved the data collection, the maintenance of the experiments, the calculations of the percentages, and the producing of report. Many of these contents had not yet been studied in other disciplines, but were developed in the discipline of science, respecting prior knowledge and cognitive abilities. The use of experiments was effective for the construction of new knowledge and to develop skills necessary to start the search.

  5. The interactions between ionic surfactants and phosphatidylcholine vesicles: Conductometry

    Science.gov (United States)

    Tsao, Heng-Kwong; Tseng, Wen Liang

    2001-11-01

    The interaction between ionic surfactants and phosphatidylcholine vesicles, which are prepared without addition of buffer and salt, is investigated by conductivity measurements. On the basis of the vesicle acting as a trap of charge carriers, the bilayer/aqueous phase partition coefficient K and the surfactant/lipid molar ratio Re of nine surfactants are determined. The thermodynamic consistency is satisfied by the measured parameters. The effects of the alkyl chain length (C10-C16) and ionic head group are then studied. The inverse partition coefficient K-1 is linearly related to the critical micelle concentration. The solubilizing ability Reb is a consequence of the competition between the surfactant incorporation into the bilayer and the formation of micelles. Consequently, the K parameter rises whereas the Reb parameter declines as the chain length is increased. The influence due to addition of salt is also discussed.

  6. Thermal and active fluctuations of a compressible bilayer vesicle

    Science.gov (United States)

    Sachin Krishnan, T. V.; Yasuda, Kento; Okamoto, Ryuichi; Komura, Shigeyuki

    2018-05-01

    We discuss thermal and active fluctuations of a compressible bilayer vesicle by using the results of hydrodynamic theory for vesicles. Coupled Langevin equations for the membrane deformation and the density fields are employed to calculate the power spectral density matrix of membrane fluctuations. Thermal contribution is obtained by means of the fluctuation dissipation theorem, whereas active contribution is calculated from exponentially decaying time correlation functions of active random forces. We obtain the total power spectral density as a sum of thermal and active contributions. An apparent response function is further calculated in order to compare with the recent microrheology experiment on red blood cells. An enhanced response is predicted in the low-frequency regime for non-thermal active fluctuations.

  7. Imaging and Quantification of Extracellular Vesicles by Transmission Electron Microscopy.

    Science.gov (United States)

    Linares, Romain; Tan, Sisareuth; Gounou, Céline; Brisson, Alain R

    2017-01-01

    Extracellular vesicles (EVs) are cell-derived vesicles that are present in blood and other body fluids. EVs raise major interest for their diverse physiopathological roles and their potential biomedical applications. However, the characterization and quantification of EVs constitute major challenges, mainly due to their small size and the lack of methods adapted for their study. Electron microscopy has made significant contributions to the EV field since their initial discovery. Here, we describe the use of two transmission electron microscopy (TEM) techniques for imaging and quantifying EVs. Cryo-TEM combined with receptor-specific gold labeling is applied to reveal the morphology, size, and phenotype of EVs, while their enumeration is achieved after high-speed sedimentation on EM grids.

  8. Importance of vesicle release stochasticity in neuro-spike communication.

    Science.gov (United States)

    Ramezani, Hamideh; Akan, Ozgur B

    2017-07-01

    Aim of this paper is proposing a stochastic model for vesicle release process, a part of neuro-spike communication. Hence, we study biological events occurring in this process and use microphysiological simulations to observe functionality of these events. Since the most important source of variability in vesicle release probability is opening of voltage dependent calcium channels (VDCCs) followed by influx of calcium ions through these channels, we propose a stochastic model for this event, while using a deterministic model for other variability sources. To capture the stochasticity of calcium influx to pre-synaptic neuron in our model, we study its statistics and find that it can be modeled by a distribution defined based on Normal and Logistic distributions.

  9. The Role of Extracellular Vesicles in Bone Metastasis

    Directory of Open Access Journals (Sweden)

    Michela Rossi

    2018-04-01

    Full Text Available Multiple types of cancer have the specific ability to home to the bone microenvironment and cause metastatic lesions. Despite being the focus of intense investigation, the molecular and cellular mechanisms that regulate the metastasis of disseminated tumor cells still remain largely unknown. Bone metastases severely impact quality of life since they are associated with pain, fractures, and bone marrow aplasia. In this review, we will summarize the recent discoveries on the role of extracellular vesicles (EV in the regulation of bone remodeling activity and bone metastasis occurrence. Indeed, it was shown that extracellular vesicles, including exosomes and microvesicles, released from tumor cells can modify the bone microenvironment, allowing the formation of osteolytic, osteosclerotic, and mixed mestastases. In turn, bone-derived EV can stimulate the proliferation of tumor cells. The inhibition of EV-mediated crosstalk between cancer and bone cells could represent a new therapeutic target for bone metastasis.

  10. Lubrication synergy: Mixture of hyaluronan and dipalmitoylphosphatidylcholine (DPPC) vesicles

    DEFF Research Database (Denmark)

    Raj, Akanksha; Wang, Min; Zander, Thomas

    2017-01-01

    consisting of non-homogeneous phospholipid bilayer with hyaluronan/DPPC aggregates on top. The presence of these aggregates generates a long-range repulsive surface force as two such surfaces are brought together. However, the aggregates are easily deformed, partly rearranged into multilayer structures......Phospholipids and hyaluronan have been implied to fulfil important roles in synovial joint lubrication. Since both components are present in synovial fluid, self-assembly structures formed by them should also be present. We demonstrate by small angle X-ray scattering that hyaluronan associates...... with the outer shell of dipalmitoylphophatidylcholine (DPPC) vesicles in bulk solution. Further, we follow adsorption to silica from mixed hyaluronan/DPPC vesicle solution by Quartz Crystal Microbalance with Dissipation measurements. Atomic Force Microscope imaging visualises the adsorbed layer structure...

  11. Pressure exerted by a vesicle on a surface

    International Nuclear Information System (INIS)

    Owczarek, A L; Prellberg, T

    2014-01-01

    Several recent works have considered the pressure exerted on a wall by a model polymer. We extend this consideration to vesicles attached to a wall, and hence include osmotic pressure. We do this by considering a two-dimensional directed model, namely that of area-weighted Dyck paths. Not surprisingly, the pressure exerted by the vesicle on the wall depends on the osmotic pressure inside, especially its sign. Here, we discuss the scaling of this pressure in the different regimes, paying particular attention to the crossover between positive and negative osmotic pressure. In our directed model, there exists an underlying Airy function scaling form, from which we extract the dependence of the bulk pressure on small osmotic pressures. (paper)

  12. Optimized microviscosimeter for detection and characterization of biological vesicles

    International Nuclear Information System (INIS)

    Gaiffe, O; Cretin, B; Boireau, W; Baudouy, J C; Vairac, P

    2008-01-01

    In this paper, we report on studies aimed at sensing the stiffness of biological membranes, in particular in the case of lipidic vesicles. To obtain pertinent results, we have developed and checked a specific sensor based on a vibrating sphere. The near-field acoustic wave generated by this vibrating sphere enables us to characterize biological particles which change the apparent viscosity and density of the surrounding fluid. The microsphere is well suited for very small volumes of liquid (typically about a few microlitres). The experimental results demonstrate the high sensitivity of the sensor to small variations of the composition of the aqueous media, particularly in the case of various populations of lipidic nanoparticles. Finally, this microviscosimeter demonstrates its ability to discriminate the population of vesicles on the basis of their global viscous properties

  13. A Phase of Liposomes with Entangled Tubular Vesicles

    Science.gov (United States)

    Chiruvolu, Shivkumar; Warriner, Heidi E.; Naranjo, Edward; Idziak, Stefan H. J.; Radler, Joachim O.; Plano, Robert J.; Zasadzinski, Joseph A.; Safinya, Cyrus R.

    1994-11-01

    An equilibrium phase belonging to the family of bilayer liposomes in ternary mixtures of dimyristoylphosphatidylcholine (DMPC), water, and geraniol (a biological alcohol derived from oil-soluble vitamins that acts as a cosurfactant) has been identified. Electron and optical microscopy reveal the phase, labeled Ltv, to be composed of highly entangled tubular vesicles. In situ x-ray diffraction confirms that the tubule walls are multilamellar with the lipids in the chain-melted state. Macroscopic observations show that the Ltv phase coexists with the well-known L_4 phase of spherical vesicles and a bulk L_α phase. However, the defining characteristic of the Ltv phase is the Weissenberg rod climbing effect under shear, which results from its polymer-like entangled microstructure.

  14. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation

    DEFF Research Database (Denmark)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun

    2015-01-01

    the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination...

  15. Phosphoproteins in extracellular vesicles as candidate markers for breast cancer

    OpenAIRE

    Chen, I-Hsuan; Xue, Liang; Hsu, Chuan-Chih; Paez, Juan Sebastian Paez; Pan, Li; Andaluz, Hillary; Wendt, Michael K.; Iliuk, Anton B.; Zhu, Jian-Kang; Tao, W. Andy

    2017-01-01

    Protein phosphorylation is a major regulatory mechanism for many cellular functions, but no phosphoprotein in biofluids has been developed for disease diagnosis because of the presence of active phosphatases. This study presents a general strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs from small volumes of plasma sam...

  16. The role of extracellular vesicles in phenotypic cancer transformation:

    OpenAIRE

    Kralj-Iglič, Veronika; Ogorevc, Eva; Veranič, Peter

    2013-01-01

    Background. Cancer has traditionally been considered as a disease resulting from gene mutations. New findings in biology are challenging gene-centered explanations of cancer progression and redirecting them to the non-genetic origins of tumorigenicity. It has become clear that intercellular communication plays a crucial role in cancer progression. Among the most intriguing ways of intercellular communication is that via extracellular vesicles (EVs). EVs are membrane structures released from v...

  17. Dimensional characterization of extracellular vesicles using atomic force microscopy

    International Nuclear Information System (INIS)

    Sebaihi, N; De Boeck, B; Pétry, J; Yuana, Y; Nieuwland, R

    2017-01-01

    Extracellular vesicles (EV) are small biological entities released from cells into body fluids. EV are recognized as mediators in intercellular communication and influence important physiological processes. It has been shown that the concentration and composition of EV in body fluids may differ from healthy subjects to patients suffering from particular disease. So, EV have gained a strong scientific and clinical interest as potential biomarkers for diagnosis and prognosis of disease. Due to their small size, accurate detection and characterization of EV remain challenging. The aim of the presented work is to propose a characterization method of erythrocyte-derived EV using atomic force microscopy (AFM). The vesicles are immobilized on anti-CD235a-modified mica and analyzed by AFM under buffer liquid and dry conditions. EV detected under both conditions show very similar sizes namely ∼30 nm high and ∼90 nm wide. The size of these vesicles remains stable over drying time as long as 7 d at room temperature. Since the detected vesicles are not spherical, EV are characterized by their height and diameter, and not only by the height as is usually done for spherical nanoparticles. In order to obtain an accurate measurement of EV diameters, the geometry of the AFM tip was evaluated to account for the lateral broadening artifact inherent to AFM measurements. To do so, spherical polystyrene (PS) nanobeads and EV were concomitantly deposited on the same mica substrate and simultaneously measured by AFM under dry conditions. By applying this procedure, direct calibration of the AFM tip could be performed together with EV characterization under identical experimental conditions minimizing external sources of uncertainty on the shape and size of the tip, thus allowing standardization of EV measurement. (paper)

  18. Structural Disorder Provides Increased Adaptability for Vesicle Trafficking Pathways

    Science.gov (United States)

    Tompa, Peter

    2013-01-01

    Vesicle trafficking systems play essential roles in the communication between the organelles of eukaryotic cells and also between cells and their environment. Endocytosis and the late secretory route are mediated by clathrin-coated vesicles, while the COat Protein I and II (COPI and COPII) routes stand for the bidirectional traffic between the ER and the Golgi apparatus. Despite similar fundamental organizations, the molecular machinery, functions, and evolutionary characteristics of the three systems are very different. In this work, we compiled the basic functional protein groups of the three main routes for human and yeast and analyzed them from the structural disorder perspective. We found similar overall disorder content in yeast and human proteins, confirming the well-conserved nature of these systems. Most functional groups contain highly disordered proteins, supporting the general importance of structural disorder in these routes, although some of them seem to heavily rely on disorder, while others do not. Interestingly, the clathrin system is significantly more disordered (∼23%) than the other two, COPI (∼9%) and COPII (∼8%). We show that this structural phenomenon enhances the inherent plasticity and increased evolutionary adaptability of the clathrin system, which distinguishes it from the other two routes. Since multi-functionality (moonlighting) is indicative of both plasticity and adaptability, we studied its prevalence in vesicle trafficking proteins and correlated it with structural disorder. Clathrin adaptors have the highest capability for moonlighting while also comprising the most highly disordered members. The ability to acquire tissue specific functions was also used to approach adaptability: clathrin route genes have the most tissue specific exons encoding for protein segments enriched in structural disorder and interaction sites. Overall, our results confirm the general importance of structural disorder in vesicle trafficking and

  19. Transfer of oleic acid between albumin and phospholipid vesicles

    International Nuclear Information System (INIS)

    Hamilton, J.A.; Cistola, D.P.

    1986-01-01

    The net transfer of oleic acid between egg phosphatidylcholine unilamellar vesicles and bovine serum albumin has been monitored by 13 C NMR spectroscopy and 90% isotopically substituted [1- 13 C]oleic acid. The carboxyl chemical shifts of oleic acid bound to albumin were different from those for oleic acid in phospholipid vesicles. Therefore, in mixtures of donor particles, the equilibrium distribution of oleic acid was determined from chemical shift and peak intensity data without separation of donor and acceptor particles. In a system containing equal masses of albumin and phospholipid and a stoichiometry of 4-5 mol of oleic acid per mol of albumin, the oleic acid distribution was pH dependent, with ≥80% of the oleic acid associated with albumin at pH 7.4; association was ≥90% at pH 8.0. Decreasing the pH below 7.4 markedly decreased the proportion of fatty acid bound to albumin. The distribution was reversible with pH and was independent of whether vesicles or albumin acted as a donor. These data suggest that pH may strongly influence the partitioning of fatty acid between cellular membranes and albumin. The 13 C NMR method is also advantageous because it provides information about the structural environments of oleic acid bound to albumin or phospholipid, the ionization state of oleic acid in each environment, and the structural integrity of the vesicles. In addition, minimum and maximum limits for the exchange rates of oleic acid among different environments were obtained from the NMR data

  20. Temperature in the seeds germination of pitaya genotypes

    Directory of Open Access Journals (Sweden)

    Alessandro Borini Lone

    2014-09-01

    Full Text Available The optimum temperature for germination of cacti vary with the species. With this work, we aimed to evaluate the seeds germination of pitaya genotypes under different temperatures. The used genotypes were: Hylocereus undatus (PB, H. polyrhizus (PV, Selenicereus megalanthus (PA, H. undatus x H. costaricensis (PH1 and H. costaricensis x H. undatus (PH2. For each genotype we used four replicates of 50 seeds, in a completely randomized design. The sowing was carried out on blotter paper in boxes type Gerbox ®, maintained at temperatures of 15, 20, 25, 30 and 35 oC constant and 15-25, 20-30 and 25-35 oC alternating with photoperiod 12 hours. The test lasted 30 days which were appraised the germination percentage, the germination speed index and the average time of germination. For seeds germination of PB, the result obtained in the temperature of 25 oC didn’t differ of the obtained to 30 and 20-30 oC, however it was superior to the others temperatures. In PV, the result at 25 oC didn’t differ of the obtained to 20 and 30 oC, being superior to the results of the others temperatures. For PA, the best result was obtained to 25 oC. In PH1, the temperatures of 25, 30 and 20-30 oC presented superiors results to the others. For PH2, the result obtained in 15-25oC didn’t differ of the obtained at 25 oC, however it was superior to the others temperatures. The constants temperatures of 25 and 30 °C and alternating 20-30 °C are suitable for germination of H. undatus and for the hybrid H. undatus x H. costaricensis. For H. polyrhizus, constant temperatures of 20, 25 to 30 °C are suitable for seed germination. The constant temperature of 25 °C is the most suitable for the germination of S. megalanthus. For the hybrid H. costaricensis x H. undatus, constant temperature of 25 °C and alternating 15-25°C are suitable for seed germination.