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Sample records for germ code gcr

  1. Galactic Cosmic Ray Event-Based Risk Model (GERM) Code

    Science.gov (United States)

    Cucinotta, Francis A.; Plante, Ianik; Ponomarev, Artem L.; Kim, Myung-Hee Y.

    2013-01-01

    This software describes the transport and energy deposition of the passage of galactic cosmic rays in astronaut tissues during space travel, or heavy ion beams in patients in cancer therapy. Space radiation risk is a probability distribution, and time-dependent biological events must be accounted for physical description of space radiation transport in tissues and cells. A stochastic model can calculate the probability density directly without unverified assumptions about shape of probability density function. The prior art of transport codes calculates the average flux and dose of particles behind spacecraft and tissue shielding. Because of the signaling times for activation and relaxation in the cell and tissue, transport code must describe temporal and microspatial density of functions to correlate DNA and oxidative damage with non-targeted effects of signals, bystander, etc. These are absolutely ignored or impossible in the prior art. The GERM code provides scientists data interpretation of experiments; modeling of beam line, shielding of target samples, and sample holders; and estimation of basic physical and biological outputs of their experiments. For mono-energetic ion beams, basic physical and biological properties are calculated for a selected ion type, such as kinetic energy, mass, charge number, absorbed dose, or fluence. Evaluated quantities are linear energy transfer (LET), range (R), absorption and fragmentation cross-sections, and the probability of nuclear interactions after 1 or 5 cm of water equivalent material. In addition, a set of biophysical properties is evaluated, such as the Poisson distribution for a specified cellular area, cell survival curves, and DNA damage yields per cell. Also, the GERM code calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle in a selected material. The GERM code makes the numerical estimates of basic

  2. Isotopic dependence of GCR fluence behind shielding

    International Nuclear Information System (INIS)

    Cucinotta, Francis A.; Wilson, John W.; Saganti, Premkumar; Hu, Xiaodong; Kim, Myung-Hee Y.; Cleghorn, Timothy; Zeitlin, Cary; Tripathi, Ram K.

    2006-01-01

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors (±100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid (∼170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past; however, less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies

  3. GCR Environmental Models I: Sensitivity Analysis for GCR Environments

    Science.gov (United States)

    Slaba, Tony C.; Blattnig, Steve R.

    2014-01-01

    Accurate galactic cosmic ray (GCR) models are required to assess crew exposure during long-duration missions to the Moon or Mars. Many of these models have been developed and compared to available measurements, with uncertainty estimates usually stated to be less than 15%. However, when the models are evaluated over a common epoch and propagated through to effective dose, relative differences exceeding 50% are observed. This indicates that the metrics used to communicate GCR model uncertainty can be better tied to exposure quantities of interest for shielding applications. This is the first of three papers focused on addressing this need. In this work, the focus is on quantifying the extent to which each GCR ion and energy group, prior to entering any shielding material or body tissue, contributes to effective dose behind shielding. Results can be used to more accurately calibrate model-free parameters and provide a mechanism for refocusing validation efforts on measurements taken over important energy regions. Results can also be used as references to guide future nuclear cross-section measurements and radiobiology experiments. It is found that GCR with Z>2 and boundary energies below 500 MeV/n induce less than 5% of the total effective dose behind shielding. This finding is important given that most of the GCR models are developed and validated against Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer (ACE/CRIS) measurements taken below 500 MeV/n. It is therefore possible for two models to very accurately reproduce the ACE/CRIS data while inducing very different effective dose values behind shielding.

  4. Mixed-field GCR Simulations for Radiobiological Research using Ground Based Accelerators

    Science.gov (United States)

    Kim, Myung-Hee Y.; Rusek, Adam; Cucinotta, Francis

    Space radiation is comprised of a large number of particle types and energies, which have differential ionization power from high energy protons to high charge and energy (HZE) particles and secondary neutrons produced by galactic cosmic rays (GCR). Ground based accelerators such as the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) are used to simulate space radiation for radiobiology research and dosimetry, electronics parts, and shielding testing using mono-energetic beams for single ion species. As a tool to support research on new risk assessment models, we have developed a stochastic model of heavy ion beams and space radiation effects, the GCR Event-based Risk Model computer code (GERMcode). For radiobiological research on mixed-field space radiation, a new GCR simulator at NSRL is proposed. The NSRL-GCR simulator, which implements the rapid switching mode and the higher energy beam extraction to 1.5 GeV/u, can integrate multiple ions into a single simulation to create GCR Z-spectrum in major energy bins. After considering the GCR environment and energy limitations of NSRL, a GCR reference field is proposed after extensive simulation studies using the GERMcode. The GCR reference field is shown to reproduce the Z and LET spectra of GCR behind shielding within 20 percents accuracy compared to simulated full GCR environments behind shielding. A major challenge for space radiobiology research is to consider chronic GCR exposure of up to 3-years in relation to simulations with cell and animal models of human risks. We discuss possible approaches to map important biological time scales in experimental models using ground-based simulation with extended exposure of up to a few weeks and fractionation approaches at a GCR simulator.

  5. GCR Environmental Models III: GCR Model Validation and Propagated Uncertainties in Effective Dose

    Science.gov (United States)

    Slaba, Tony C.; Xu, Xiaojing; Blattnig, Steve R.; Norman, Ryan B.

    2014-01-01

    This is the last of three papers focused on quantifying the uncertainty associated with galactic cosmic rays (GCR) models used for space radiation shielding applications. In the first paper, it was found that GCR ions with Z>2 and boundary energy below 500 MeV/nucleon induce less than 5% of the total effective dose behind shielding. This is an important finding since GCR model development and validation have been heavily biased toward Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer measurements below 500 MeV/nucleon. Weights were also developed that quantify the relative contribution of defined GCR energy and charge groups to effective dose behind shielding. In the second paper, it was shown that these weights could be used to efficiently propagate GCR model uncertainties into effective dose behind shielding. In this work, uncertainties are quantified for a few commonly used GCR models. A validation metric is developed that accounts for measurements uncertainty, and the metric is coupled to the fast uncertainty propagation method. For this work, the Badhwar-O'Neill (BON) 2010 and 2011 and the Matthia GCR models are compared to an extensive measurement database. It is shown that BON2011 systematically overestimates heavy ion fluxes in the range 0.5-4 GeV/nucleon. The BON2010 and BON2011 also show moderate and large errors in reproducing past solar activity near the 2000 solar maximum and 2010 solar minimum. It is found that all three models induce relative errors in effective dose in the interval [-20%, 20%] at a 68% confidence level. The BON2010 and Matthia models are found to have similar overall uncertainty estimates and are preferred for space radiation shielding applications.

  6. Organization of cytokeratin cytoskeleton and germ plasm in the vegetal cortex of Xenopus laevis oocytes depends on coding and non-coding RNAs: Three-dimensional and ultrastructural analysis

    International Nuclear Information System (INIS)

    Kloc, Malgorzata; Bilinski, Szczepan; Dougherty, Matthew T.

    2007-01-01

    Recent studies discovered a novel structural role of RNA in maintaining the integrity of the mitotic spindle and cellular cytoskeleton. In Xenopus laevis, non-coding Xlsirts and coding VegT RNAs play a structural role in anchoring localized RNAs, maintaining the organization of the cytokeratin cytoskeleton and germinal granules in the oocyte vegetal cortex and in subsequent development of the germline in the embryo. We studied the ultrastructural effects of antisense oligonucleotide driven ablation of Xlsirts and VegT RNAs on the organization of the cytokeratin, germ plasm and other components of the vegetal cortex. We developed a novel method to immunolabel and visualize cytokeratin at the electron microscopy level, which allowed us to reconstruct the ultrastructural organization of the cytokeratin network relative to the components of the vegetal cortex in Xenopus oocytes. The removal of Xlsirts and VegT RNAs not only disrupts the cytokeratin cytoskeleton but also has a profound transcript-specific effect on the anchoring and distribution of germ plasm islands and their germinal granules and the arrangement of yolk platelets within the vegetal cortex. We suggest that the cytokeratin cytoskeleton plays a role in anchoring of germ plasm islands within the vegetal cortex and germinal granules within the germ plasm islands

  7. Impact of AMS-02 Measurements on Reducing GCR Model Uncertainties

    Science.gov (United States)

    Slaba, T. C.; O'Neill, P. M.; Golge, S.; Norbury, J. W.

    2015-01-01

    For vehicle design, shield optimization, mission planning, and astronaut risk assessment, the exposure from galactic cosmic rays (GCR) poses a significant and complex problem both in low Earth orbit and in deep space. To address this problem, various computational tools have been developed to quantify the exposure and risk in a wide range of scenarios. Generally, the tool used to describe the ambient GCR environment provides the input into subsequent computational tools and is therefore a critical component of end-to-end procedures. Over the past few years, several researchers have independently and very carefully compared some of the widely used GCR models to more rigorously characterize model differences and quantify uncertainties. All of the GCR models studied rely heavily on calibrating to available near-Earth measurements of GCR particle energy spectra, typically over restricted energy regions and short time periods. In this work, we first review recent sensitivity studies quantifying the ions and energies in the ambient GCR environment of greatest importance to exposure quantities behind shielding. Currently available measurements used to calibrate and validate GCR models are also summarized within this context. It is shown that the AMS-II measurements will fill a critically important gap in the measurement database. The emergence of AMS-II measurements also provides a unique opportunity to validate existing models against measurements that were not used to calibrate free parameters in the empirical descriptions. Discussion is given regarding rigorous approaches to implement the independent validation efforts, followed by recalibration of empirical parameters.

  8. Simulations of GCR interactions within planetary bodies using GEANT4

    Science.gov (United States)

    Mesick, K.; Feldman, W. C.; Stonehill, L. C.; Coupland, D. D. S.

    2017-12-01

    On planetary bodies with little to no atmosphere, Galactic Cosmic Rays (GCRs) can hit the body and produce neutrons primarily through nuclear spallation within the top few meters of the surfaces. These neutrons undergo further nuclear interactions with elements near the planetary surface and some will escape the surface and can be detected by landed or orbiting neutron radiation detector instruments. The neutron leakage signal at fast neutron energies provides a measure of average atomic mass of the near-surface material and in the epithermal and thermal energy ranges is highly sensitive to the presence of hydrogen. Gamma-rays can also escape the surface, produced at characteristic energies depending on surface composition, and can be detected by gamma-ray instruments. The intra-nuclear cascade (INC) that occurs when high-energy GCRs interact with elements within a planetary surface to produce the leakage neutron and gamma-ray signals is highly complex, and therefore Monte Carlo based radiation transport simulations are commonly used for predicting and interpreting measurements from planetary neutron and gamma-ray spectroscopy instruments. In the past, the simulation code that has been widely used for this type of analysis is MCNPX [1], which was benchmarked against data from the Lunar Neutron Probe Experiment (LPNE) on Apollo 17 [2]. In this work, we consider the validity of the radiation transport code GEANT4 [3], another widely used but open-source code, by benchmarking simulated predictions of the LPNE experiment to the Apollo 17 data. We consider the impact of different physics model options on the results, and show which models best describe the INC based on agreement with the Apollo 17 data. The success of this validation then gives us confidence in using GEANT4 to simulate GCR-induced neutron leakage signals on Mars in relevance to a re-analysis of Mars Odyssey Neutron Spectrometer data. References [1] D.B. Pelowitz, Los Alamos National Laboratory, LA-CP-05

  9. A Testis-Specific Long Non-Coding RNA, lncRNA-Tcam1, Regulates Immune-Related Genes in Mouse Male Germ Cells

    Directory of Open Access Journals (Sweden)

    Misuzu Kurihara

    2017-11-01

    Full Text Available Spermatogenesis is precisely controlled by hormones from the hypothalamus–pituitary–gonadal axis and testis-specific genes, but the regulatory mechanism is not fully understood. Recently, a large number of long non-coding RNAs (lncRNAs are found to be transcribed at each stage of meiosis of male germ cells, and their functions in spermatogenesis have yet to be fully investigated. lncRNA-testicular cell adhesion molecule 1 (lncRNA-Tcam1 is a nuclear lncRNA which is specifically expressed in mouse male germ cells and presumed to play a role in gene regulation during meiosis. Here, we present the identification of potential target genes of lncRNA-Tcam1 using spermatocyte-derived GC-2spd(ts cells. Initially, 55 target gene candidates were detected by RNA-sequencing of two GC-2spd(ts cell clones that were stably transfected with transgenes to express lncRNA-Tcam1 at different levels. Expression of 21 genes of the candidates was found to be correlated with lncRNA-Tcam1 at 7–14 postnatal days, when lncRNA-Tcam1 expression was elevated. Subsequently, we examined expression levels of the 21 genes in other two GC-2spd(ts clones, and 11 genes exhibited the correlation with lncRNA-Tcam1. Induction of lncRNA-Tcam1 transcription using the Tet-off system verified that six genes, Trim30a, Ifit3, Tgtp2, Ifi47, Oas1g, and Gbp3, were upregulated in GC-2spd(ts cells, indicating that lncRNA-Tcam1 is responsible for the regulation of gene expression of the six genes. In addition, five of the six genes, namely, Ifit3, Tgtp2, Ifi47, Oas1g, and Gbp3, are immune response genes, and Trim30a is a negative regulator of immune response. Altogether, the present study suggests that lncRNA-Tcam1 is responsible for gene regulation for the immune response during spermatogenesis.

  10. Evaluation of abrasion of a modified drainage mixture with rubber waste crushed (GCR

    Directory of Open Access Journals (Sweden)

    Yee Wan Yung Vargas

    2017-02-01

    Conclusion: The results showed that there is a highlighted influence of mix temperature (between asphalt and GCR and compaction temperature (modified asphalt and aggregate on the behavior of the MD modified with GCR.

  11. Proton Dominance of Sub-LET Threshold GCR SEE Rate

    NARCIS (Netherlands)

    Alia, Ruben Garcia; Brugger, Markus; Ferlet-Cavrois, Veronique; Brandenburg, Sytze; Calcutt, Jordan; Cerutti, Francesco; Daly, Eamonn; Ferrari, Alfredo; Muschitiello, Michele; Santin, Giovanni; Uznanski, Slawosz; Van Goethem, Marc-Jan; Zadeh, Ali

    We apply a Monte Carlo based integral rectangular parallel-piped (IRRP) approach to evaluate the impact of heavy ion reaction products on the Galactic Cosmic Ray (GCR) Single Event Effect (SEE) rate, concluding that owing to their similar high-energy (> 100 MeV/n) SEE cross section and much larger

  12. Development of a GCR Event-based Risk Model

    Science.gov (United States)

    Cucinotta, Francis A.; Ponomarev, Artem L.; Plante, Ianik; Carra, Claudio; Kim, Myung-Hee

    2009-01-01

    A goal at NASA is to develop event-based systems biology models of space radiation risks that will replace the current dose-based empirical models. Complex and varied biochemical signaling processes transmit the initial DNA and oxidative damage from space radiation into cellular and tissue responses. Mis-repaired damage or aberrant signals can lead to genomic instability, persistent oxidative stress or inflammation, which are causative of cancer and CNS risks. Protective signaling through adaptive responses or cell repopulation is also possible. We are developing a computational simulation approach to galactic cosmic ray (GCR) effects that is based on biological events rather than average quantities such as dose, fluence, or dose equivalent. The goal of the GCR Event-based Risk Model (GERMcode) is to provide a simulation tool to describe and integrate physical and biological events into stochastic models of space radiation risks. We used the quantum multiple scattering model of heavy ion fragmentation (QMSFRG) and well known energy loss processes to develop a stochastic Monte-Carlo based model of GCR transport in spacecraft shielding and tissue. We validated the accuracy of the model by comparing to physical data from the NASA Space Radiation Laboratory (NSRL). Our simulation approach allows us to time-tag each GCR proton or heavy ion interaction in tissue including correlated secondary ions often of high multiplicity. Conventional space radiation risk assessment employs average quantities, and assumes linearity and additivity of responses over the complete range of GCR charge and energies. To investigate possible deviations from these assumptions, we studied several biological response pathway models of varying induction and relaxation times including the ATM, TGF -Smad, and WNT signaling pathways. We then considered small volumes of interacting cells and the time-dependent biophysical events that the GCR would produce within these tissue volumes to estimate how

  13. Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

    Science.gov (United States)

    Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

    2013-08-01

    Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

  14. GCR Transport in the Brain: Assessment of Self-Shielding, Columnar Damage, and Nuclear Reactions on Cell Inactivation Rates

    Science.gov (United States)

    Shavers, M. R.; Atwell, W.; Cucinotta, F. A.; Badhwar, G. D. (Technical Monitor)

    1999-01-01

    cell killing from GCR, including patterns of cell killing from single particle tracks. can provide useful information on expected differences between proton and HZE tracks and clinical experiences with photon irradiation. To model effects on cells in the brain, it is important that transport models accurately describe changes in the GCR due to interactions in the cranium and proximate tissues. We describe calculations of the attenuated GCR particle fluxes at three dose-points in the brain and associated patterns of cell killing using biophysical models. The effects of the brain self-shielding and bone-tissue interface of the skull in modulating the GCR environment are considered. For each brain dose-point, the mass distribution in the surrounding 4(pi) solid angle is characterized using the CAM model to trace 512 rays. The CAM model describes the self-shielding by converting the tissue distribution to mass-equivalent aluminum, and nominal values of spacecraft shielding is considered. Particle transport is performed with the proton, neutron, and heavy-ion transport code HZETRN with the nuclear fragmentation model QMSFRG. The distribution of cells killed along the path of individual GCR ions is modeled using in vitro cell inactivation data for cells with varying sensitivity. Monte Carlo simulations of arrays of inactivated cells are considered for protons and heavy ions and used to describe the absolute number of cell killing events of various magnitude in the brain from the GCR. Included are simulations of positions of inactivated cells from stopping heavy ions and nuclear stars produced by high-energy ions most importantly, protons and neutrons.

  15. Modulation of GCR in Various Types of Helispheric Magnetic Field

    Science.gov (United States)

    Kobylinski, Z.; Bochorishvili, T.

    We make an attempt to compare the modulation of galactic cosmic rays (GCR) as the result of various assumptions referred to heliospheric magnetic field (HMF). The steady state version of 3D Parker cosmic ray transport equation (TPE), with drift included, is solved num erically in the spherically symmetric heliosphere. We take into account four cases of the possible magnetic field configuration: standard Parker HMF, Parker field with modifications in polar direction done by Jokippi and K ta (2) and Smith ando Bieber (3) , Fisk type of field (4). In the last one we assume the existence north and south polar coronal holes in the inner corona with central point inclined from the rotation of the Sun. At the polar regions of the heliosphere the isotropic diffusion of GCR is assumed. The results of calculation s will be discussed in detail. The (4) model more reduces an acces s of galactic particles from polar direction into solar system than others.

  16. Preliminary Sensitivity Study on Gas-Cooled Reactor for NHDD System Using MARS-GCR

    International Nuclear Information System (INIS)

    Lee, Seung Wook; Jeong, Jae Jun; Lee, Won Jae

    2005-01-01

    A Gas-Cooled Reactor (GCR) is considered as one of the most outstanding tools for a massive hydrogen production without CO 2 emission. Till now, two types of GCR are regarded as a viable nuclear reactor for a hydrogen production: Prismatic Modular Reactor (PMR), Pebble Bed Reactor (PBR). In this paper, a preliminary sensitivity study on two types of GCR is carried out by using MARS-GCR to find out the effect on the peak fuel and reactor pressure vessel (RPV) temperature, with varying the condition of a reactor inlet, outlet temperature, and system pressure for both PMR and PBR

  17. A Tailorable Structural Composite for GCR and Albedo Neutron Protection on the Lunar Surface, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A tailorable structural composite that will provide protection from the lunar radiation environment, including GCR and albedo neutrons will be developed. This...

  18. Trehalose, glycogen and ethanol metabolism in the gcr1 mutant of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Seker, Tamay; Hamamci, H.

    2003-01-01

    Since Gcr1p is pivotal in controlling the transcription of glycolytic enzymes and trehalose metabolism seems to be one of the control points of glycolysis, we examined trehalose and glycogen synthesis in response to 2 % glucose pulse during batch growth in gcr1 (glucose regulation-1) mutant lacking...

  19. Early Results from the Advanced Radiation Protection Thick GCR Shielding Project

    Science.gov (United States)

    Norman, Ryan B.; Clowdsley, Martha; Slaba, Tony; Heilbronn, Lawrence; Zeitlin, Cary; Kenny, Sean; Crespo, Luis; Giesy, Daniel; Warner, James; McGirl, Natalie; hide

    2017-01-01

    The Advanced Radiation Protection Thick Galactic Cosmic Ray (GCR) Shielding Project leverages experimental and modeling approaches to validate a predicted minimum in the radiation exposure versus shielding depth curve. Preliminary results of space radiation models indicate that a minimum in the dose equivalent versus aluminum shielding thickness may exist in the 20-30 g/cm2 region. For greater shield thickness, dose equivalent increases due to secondary neutron and light particle production. This result goes against the long held belief in the space radiation shielding community that increasing shielding thickness will decrease risk to crew health. A comprehensive modeling effort was undertaken to verify the preliminary modeling results using multiple Monte Carlo and deterministic space radiation transport codes. These results verified the preliminary findings of a minimum and helped drive the design of the experimental component of the project. In first-of-their-kind experiments performed at the NASA Space Radiation Laboratory, neutrons and light ions were measured between large thicknesses of aluminum shielding. Both an upstream and a downstream shield were incorporated into the experiment to represent the radiation environment inside a spacecraft. These measurements are used to validate the Monte Carlo codes and derive uncertainty distributions for exposure estimates behind thick shielding similar to that provided by spacecraft on a Mars mission. Preliminary results for all aspects of the project will be presented.

  20. Comparison of Space Radiation Calculations from Deterministic and Monte Carlo Transport Codes

    Science.gov (United States)

    Adams, J. H.; Lin, Z. W.; Nasser, A. F.; Randeniya, S.; Tripathi, r. K.; Watts, J. W.; Yepes, P.

    2010-01-01

    The presentation outline includes motivation, radiation transport codes being considered, space radiation cases being considered, results for slab geometry, results from spherical geometry, and summary. ///////// main physics in radiation transport codes hzetrn uprop fluka geant4, slab geometry, spe, gcr,

  1. EDF's (Electricite de France) in service control for GCR type reactor vessels

    International Nuclear Information System (INIS)

    Douillet, M.G.

    1979-01-01

    This paper presents the performance of the data acquisition and processing systems developed by the French EDF for controlling and testing the mechanical properties (thermal stress, deformations, cracks,...) of prestressed concrete vessels for GCR type reactors

  2. The GCR2 gene family is not required for ABA control of seed germination and early seedling development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jianjun Guo

    Full Text Available BACKGROUND: The plant hormone abscisic acid (ABA regulates diverse processes of plant growth and development. It has recently been proposed that GCR2 functions as a G-protein-coupled receptor (GPCR for ABA. However, the structural relationships and functionality of GCR2 have been challenged by several independent studies. A central question in this controversy is whether gcr2 mutants are insensitive to ABA, because gcr2 mutants were shown to display reduced sensitivity to ABA under one experimental condition (e.g. 22 degrees C, continuous white light with 150 micromol m(-2 s(-1 but were shown to display wild-type sensitivity under another slightly different condition (e.g. 23 degrees C, 14/10 hr photoperiod with 120 micromol m(-2 s(-1. It has been hypothesized that gcr2 appears only weakly insensitive to ABA because two other GCR2-like genes in Arabidopsis, GCL1 and GCL2, compensate for the loss of function of GCR2. PRINCIPAL FINDINGS: In order to test this hypothesis, we isolated a putative loss-of-function allele of GCL2, and then generated all possible combinations of mutations in each member of the GCR2 gene family. We found that all double mutants, including gcr2 gcl1, gcr2 gcl2, gcl1 gcl2, as well as the gcr2 gcl1 gcl2 triple mutant displayed wild-type sensitivity to ABA in seed germination and early seedling development assays, demonstrating that the GCR2 gene family is not required for ABA responses in these processes. CONCLUSION: These results provide compelling genetic evidence that GCR2 is unlikely to act as a receptor for ABA in the context of either seed germination or early seedling development.

  3. A new gcrR-deficient Streptococcus mutans mutant for replacement therapy of dental caries.

    Science.gov (United States)

    Pan, Wenting; Mao, Tiantian; Xu, Qing-an; Shao, Jin; Liu, Chang; Fan, Mingwen

    2013-01-01

    gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy. In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model. Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159. These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.

  4. A New gcrR-Deficient Streptococcus mutans Mutant for Replacement Therapy of Dental Caries

    Directory of Open Access Journals (Sweden)

    Wenting Pan

    2013-01-01

    Full Text Available Background. gcrR gene acts as a negative regulator related to sucrose-dependent adherence in S. mutans. It is constructive to test the potential capacity of mutans with gcrR gene deficient in bacteria replacement therapy. Methods. In this study, we constructed the mutant by homologous recombination. The morphological characteristics of biofilms were analyzed by confocal laser scanning microscopy. S. mutans UA159 and the mutant MS-gcrR-def were inoculated, respectively, or together for competitive testing in vitro and in rat model. Results. Adhesion assay showed that the adhesion ability of the mutant increased relative to the wild type, especially in the early stage. MS-gcrR-def out-competed S. mutans UA159 in vitro biofilm, and correspondingly coinfection displayed significantly fewer caries in vivo. The former possessed both a lower level of acid production and a stronger colonization potential than S. mutans UA159. Conclusion. These findings demonstrate that MS-gcrR-def appears to be a good candidate for replacement therapy.

  5. Avian Primordial Germ Cells.

    Science.gov (United States)

    Tagami, Takahiro; Miyahara, Daichi; Nakamura, Yoshiaki

    2017-01-01

    Germ cells transmit genetic information to the next generation through gametogenesis. Primordial germ cells (PGCs) are the first germ-cell population established during development, and are the common origins of both oocytes and spermatogonia. Unlike in other species, PGCs in birds undergo blood circulation to migrate toward the genital ridge, and are one of the major biological properties of avian PGCs. Germ cells enter meiosis and arrest at prophase I during embryogenesis in females, whereas in males they enter mitotic arrest during embryogenesis and enter meiosis only after birth. In chicken, gonadal sex differentiation occurs as early as embryonic day 6, but meiotic initiation of female germ cells starts from a relatively late stage (embryonic day 15.5). Retinoic acid controls meiotic entry in developing chicken gonads through the expressions of retinaldehyde dehydrogenase 2, a major retinoic acid synthesizing enzyme, and cytochrome P450 family 26, subfamily B member 1, a major retinoic acid-degrading enzyme. The other major biological property of avian PGCs is that they can be propagated in vitro for the long term, and this technique is useful for investigating proliferation mechanisms. The main factor involved in chicken PGC proliferation is fibroblast growth factor 2, which activates the signaling of MEK/ERK and thus promotes the cell cycle and anti-apoptosis. Furthermore, the activation of PI3K/Akt signaling is indispensable for the proliferation and survival of chicken PGCs.

  6. Foodborne Germs and Illnesses

    Science.gov (United States)

    ... Español (Spanish) Recommend on Facebook Tweet Share Compartir What Causes Food Poisoning? Many different disease-causing germs can contaminate ... email address: Enter Email Address What’s this? Submit What's this? Submit Button ... of Foodborne Illness in the U.S. Food Safety is a CDC Winnable Battle Foodborne Illness ...

  7. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 ... Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/01/0084-0088 ...

  8. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 Issue 1 January 2001 pp 84-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. Opening a Window on ICME-driven GCR Modulation in the Inner Solar System

    Science.gov (United States)

    Winslow, Reka M.; Schwadron, Nathan A.; Lugaz, Noé; Guo, Jingnan; Joyce, Colin J.; Jordan, Andrew P.; Wilson, Jody K.; Spence, Harlan E.; Lawrence, David J.; Wimmer-Schweingruber, Robert F.; Mays, M. Leila

    2018-04-01

    Interplanetary coronal mass ejections (ICMEs) often cause Forbush decreases (Fds) in the flux of galactic cosmic rays (GCRs). We investigate how a single ICME, launched from the Sun on 2014 February 12, affected GCR fluxes at Mercury, Earth, and Mars. We use GCR observations from MESSENGER at Mercury, ACE/LRO at the Earth/Moon, and MSL at Mars. We find that Fds are steeper and deeper closer to the Sun, and that the magnitude of the magnetic field in the ICME magnetic ejecta as well as the “strength” of the ICME sheath both play a large role in modulating the depth of the Fd. Based on our results, we hypothesize that (1) the Fd size decreases exponentially with heliocentric distance, and (2) that two-step Fds are more common closer to the Sun. Both hypotheses will be directly verifiable by the upcoming Parker Solar Probe and Solar Orbiter missions. This investigation provides the first systematic study of the changes in GCR modulation as a function of distance from the Sun using nearly contemporaneous observations at Mercury, Earth/Moon, and Mars, which will be critical for validating our physical understanding of the modulation process throughout the heliosphere.

  10. Diagnostic markers for germ cell neoplasms

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, Ewa; Nielsen, John E; Skakkebaek, Niels E

    2015-01-01

    to gain-of function mutations in survival-promoting genes (e.g. FGFR3, HRAS), thus this tumour has a different expression profile than GCNIS-derived TGCT. Clinically most informative markers for GCT, except teratoma, are genes expressed in primordial germ cell/gonocyte and embryonic pluripotency......-genomic gene expression regulation involves small non-coding RNAs, predominantly micro-RNAs (miRs). Testicular GCTs display micro-RNA profiles similar to embryonic stem cells. Targeted miRNA-based blood tests for miR-371-3 and miR-367 clusters are currently under development and hold a great promise......This concise review summarises tissue and serum markers useful for differential diagnosis of germ cell tumours (GCTs), with focus on the most common testicular GCTs (TGCTs). GCTs are characterised by phenotypic heterogeneity due to largely retained embryonic pluripotency and aberrant somatic...

  11. OpenQ∗D simulation code for QCD+QED

    DEFF Research Database (Denmark)

    Campos, Isabel; Fritzsch, Patrick; Hansen, Martin

    2018-01-01

    The openQ∗D code for the simulation of QCD+QED with C∗ boundary conditions is presented. This code is based on openQCD-1.6, from which it inherits the core features that ensure its efficiency: the locally-deflated SAP-preconditioned GCR solver, the twisted-mass frequency splitting of the fermion...

  12. Computational Model Prediction and Biological Validation Using Simplified Mixed Field Exposures for the Development of a GCR Reference Field

    Science.gov (United States)

    Hada, M.; Rhone, J.; Beitman, A.; Saganti, P.; Plante, I.; Ponomarev, A.; Slaba, T.; Patel, Z.

    2018-01-01

    acute exposures of the mixed field beams used for the experiments. The chromosomes were simulated by a polymer random walk algorithm with restrictions to their respective domains in the nucleus [1]. The stochastic dose to the nucleus was calculated with the code RITRACKS [2]. Irradiation of a target volume by a mixed field of ions was implemented within RITRACKs, and the fields of ions can be delivered over specific periods of time, allowing the simulation of dose-rate effects. Similarly, particles of various types and energies extracted from a pre-calculated spectra of galactic cosmic rays (GCR) can be used in RITRACKS. The number and spatial location of DSBs (DNA double-strand breaks) were calculated in BDSTRACKS using the simulated chromosomes and local (voxel) dose. Assuming that DSBs led to chromosome breaks, and simulating the rejoining of damaged chromosomes occurring during repair, BDSTRACKS produces the yield of various types of chromosome aberrations as a function of time (only final yields are presented). A comparison between experimental and simulation results will be shown.

  13. Opening a Window on ICME Evolution and GCR Modulation During Propagation in the Innermost Heliosphere

    Science.gov (United States)

    Winslow, R. M.; Lugaz, N.; Schwadron, N.; Farrugia, C. J.; Guo, J.; Wimmer-Schweingruber, R. F.; Wilson, J. K.; Joyce, C.; Jordan, A.; Lawrence, D. J.

    2017-12-01

    We use multipoint spacecraft observations to study interplanetary coronal mass ejection (ICME) evolution and subsequent galactic cosmic ray (GCR) modulation during propagation in the inner heliosphere. We illustrate ICME propagation effects through two different case studies. The first ICME was launched from the Sun on 29 December 2011 and was observed in near-perfect longitudinal conjunction at MESSENGER and STEREO A. Despite the close longitudinal alignment, we infer from force-free field modeling that the orientation of the underlying flux rope rotated ˜80o in latitude and ˜65o in longitude. Based on both spacecraft measurements as well as ENLIL model simulations of the steady state solar wind, we find that interactions involving magnetic reconnection with corotating structures in the solar wind dramatically alter the ICME magnetic field. In particular, we observed at STEREO A a highly turbulent region with distinct properties within the flux rope that was not observed at MESSENGER; we attribute this region to interaction between the ICME and a heliospheric plasma sheet/current sheet. This is a concrete example of a sequence of events that can increase the complexity of ICMEs during propagation and should serve as a caution on using very distant observations to predict the geoeffectiveness of large interplanetary transients. Our second case study investigates changes with heliospheric distance in GCR modulation by an ICME event (launched on 12 February 2014) observed in near-conjunction at all four of the inner solar system planets. The ICME caused Forbush decreases (FDs) in the GCR count rates at Mercury (MESSENGER), Earth/Moon (ACE/LRO), and Mars (MSL). At all three locations, the pre-ICME background GCR rate was well-matched, but the depth of the FD of GCR fluxes with similar energy ranges diminished with distance from the Sun. A larger difference in FD size was observed between Mercury and Earth than between Earth and Mars, partly owing to the much larger

  14. Primordial Germ Cells in Mice

    OpenAIRE

    Saitou, Mitinori; Yamaji, Masashi

    2012-01-01

    Germ cell development creates totipotency through genetic as well as epigenetic regulation of the genome function. Primordial germ cells (PGCs) are the first germ cell population established during development and are immediate precursors for both the oocytes and spermatogonia. We here summarize recent findings regarding the mechanism of PGC development in mice. We focus on the transcriptional and signaling mechanism for PGC specification, potential pluripotency, and epigenetic reprogramming ...

  15. Stages of Childhood Extracranial Germ Cell Tumors

    Science.gov (United States)

    ... markers . Most malignant germ cell tumors release tumor markers. The following tumor markers are used to detect extracranial germ cell tumors: ... testicular germ cell tumors, blood levels of the tumor markers help show if the tumor is a seminoma ...

  16. Germ killing by ultraviolet radiation

    International Nuclear Information System (INIS)

    Wawrik, O.

    1975-01-01

    Short-wave UV radiation, in particular the range about 250 nm, has a high germ reducing effect. Corresponding UV burners which above all emit radiation at the line of 254 nm can therefore be used effectively in all cases where the least possible content of germs in the air is aimed at. Apart from this it is also possible to reduce by this process the germs on surfaces and liquids. Especially in the most various ranges of pharmaceutical production one is steadily striving for efficient and last not least economic procedures by which it is possible to reduce the germs present in the air of a room. Numerous scientific investigations have sufficiently proved that short-wave UV radiation is extremely well appropriate for such purposes. Absolutely germ-free air in a room can only be obtained under laboratory conditions. In practice, however, the aim is not to achieve a 100 per cent killing of the germs present in a room but to make sure that the germ rate in certain rooms is constantly reduced to the lowest possible level. If in this connection it is referred to a germ reduction of 100 or 99 per cent this is but theory. (orig.) [de

  17. Primordial Germ Cells in Mice

    Science.gov (United States)

    Saitou, Mitinori; Yamaji, Masashi

    2012-01-01

    Germ cell development creates totipotency through genetic as well as epigenetic regulation of the genome function. Primordial germ cells (PGCs) are the first germ cell population established during development and are immediate precursors for both the oocytes and spermatogonia. We here summarize recent findings regarding the mechanism of PGC development in mice. We focus on the transcriptional and signaling mechanism for PGC specification, potential pluripotency, and epigenetic reprogramming in PGCs and strategies for the reconstitution of germ cell development using pluripotent stem cells in culture. Continued studies on germ cell development may lead to the generation of totipotency in vitro, which should have a profound influence on biological science as well as on medicine. PMID:23125014

  18. Miniaturized Hollow-Waveguide Gas Correlation Radiometer (GCR) for Trace Gas Detection in the Martian Atmosphere

    Science.gov (United States)

    Wilson, Emily L.; Georgieva, E. M.; Melroy, H. R.

    2012-01-01

    Gas correlation radiometry (GCR) has been shown to be a sensitive and versatile method for detecting trace gases in Earth's atmosphere. Here, we present a miniaturized and simplified version of this instrument capable of mapping multiple trace gases and identifying active regions on the Mars surface. Reduction of the size and mass of the GCR instrument has been achieved by implementing a lightweight, 1 mm inner diameter hollow-core optical fiber (hollow waveguide) for the gas correlation cell. Based on a comparison with an Earth orbiting CO2 gas correlation instrument, replacement of the 10 meter mUltipass cell with hollow waveguide of equivalent pathlength reduces the cell mass from approx 150 kg to approx 0.5 kg, and reduces the volume from 1.9 m x 1.3 m x 0.86 m to a small bundle of fiber coils approximately I meter in diameter by 0.05 m in height (mass and volume reductions of >99%). This modular instrument technique can be expanded to include measurements of additional species of interest including nitrous oxide (N2O), hydrogen sulfide (H2S), methanol (CH3OH), and sulfur dioxide (SO2), as well as carbon dioxide (CO2) for a simultaneous measure of mass balance.

  19. Causes and evolutionary consequences of primordial germ-cell specification mode in metazoans.

    Science.gov (United States)

    Whittle, Carrie A; Extavour, Cassandra G

    2017-06-06

    In animals, primordial germ cells (PGCs) give rise to the germ lines, the cell lineages that produce sperm and eggs. PGCs form in embryogenesis, typically by one of two modes: a likely ancestral mode wherein germ cells are induced during embryogenesis by cell-cell signaling (induction) or a derived mechanism whereby germ cells are specified by using germ plasm-that is, maternally specified germ-line determinants (inheritance). The causes of the shift to germ plasm for PGC specification in some animal clades remain largely unknown, but its repeated convergent evolution raises the question of whether it may result from or confer an innate selective advantage. It has been hypothesized that the acquisition of germ plasm confers enhanced evolvability, resulting from the release of selective constraint on somatic gene networks in embryogenesis, thus leading to acceleration of an organism's protein-sequence evolution, particularly for genes expressed at early developmental stages, and resulting in high speciation rates in germ plasm-containing lineages (denoted herein as the "PGC-specification hypothesis"). Although that hypothesis, if supported, could have major implications for animal evolution, our recent large-scale coding-sequence analyses from vertebrates and invertebrates provided important examples of genera that do not support the hypothesis of liberated constraint under germ plasm. Here, we consider reasons why germ plasm might be neither a direct target of selection nor causally linked to accelerated animal evolution. We explore alternate scenarios that could explain the repeated evolution of germ plasm and propose potential consequences of the inheritance and induction modes to animal evolutionary biology.

  20. Role of Axumin PET Scan in Germ Cell Tumor

    Science.gov (United States)

    2018-05-01

    Testis Cancer; Germ Cell Tumor; Testicular Cancer; Germ Cell Tumor of Testis; Germ Cell Tumor, Testicular, Childhood; Testicular Neoplasms; Testicular Germ Cell Tumor; Testicular Yolk Sac Tumor; Testicular Choriocarcinoma; Testicular Diseases; Germ Cell Cancer Metastatic; Germ Cell Neoplasm of Retroperitoneum; Germ Cell Cancer, Nos

  1. Relation of hardness with FWHM and residual stress of GCr15 steel after shot peening

    Science.gov (United States)

    Fu, Peng; Chu, Ruiqing; Xu, Zhijun; Ding, Guanjun; Jiang, Chuanhai

    2018-02-01

    The variations of XRD full width at half maximum (FWHM), residual stress and hardness for the surface of GCr15 steel after triple shot peening (TSP) as a function of annealing time and temperature are studied. The results show that with the increase of annealing temperature and time, hardness and FWHM increase gradually while compressive residual stress (CRS) decreases gradually. CRS and micro- structure work together on the hardness values, and the micro-structure is the most important factor for hardness. According to establishing the quantitive relationship of hardness with FWHM and CRS, the value of hardness can be calculated; a new type of noncontact and nondestructive hardness testing can be realized by XRD method.

  2. Precipitation Behaviors of TiN Inclusion in GCr15 Bearing Steel Billet

    Science.gov (United States)

    Tian, Qianren; Wang, Guocheng; Zhao, Yang; Li, Jing; Wang, Qi

    2018-03-01

    There are many types of non-metallic TiN-based inclusions observed in GCr15 bearing steel, including single-particle TiN, multi-particle polymerized TiN, and complex inclusions like TiN-MnS, TiN-MgO-MgAl2O4 (TiN-MgO-MA), and TiN-MgAl2O4-MnS (TiN-MA-MnS). Thermodynamic calculations suggest that single-particle TiN precipitates dominate the mushy zone of GCr15 bearing steel. Kinetic calculations regarding TiN growth suggest that the final size of the single-particle TiN ranges between 1 and 6 μm in the initial concentration range of [pct Ti] = 0.0060 to 0.0079 and [pct N] = 0.0049 to 0.0070, at 1620 to 1640 K and a local cooling rate of 0.5 to 10 K/s. The multi-particle polymerized TiN are formed by single TiN particles in three stages: single-particle TiN inclusions approach each other drawn by the cavity bridge force (CBF), local active angles consolidate, and neck region sintering occurs. Based on the thermodynamic calculations of TiN, MnS, and MgO precipitation, the formation behaviors of complex inclusions of TiN-MnS, TiN-MgO-MA, and TiN-MA-MnS were investigated.

  3. Results of Simulated Galactic Cosmic Radiation (GCR) and Solar Particle Events (SPE) on Spectra Restraint Fabric

    Science.gov (United States)

    Peters, Benjamin; Hussain, Sarosh; Waller, Jess

    2017-01-01

    Spectra or similar Ultra-high-molecular-weight polyethylene (UHMWPE) fabric is the likely choice for future structural space suit restraint materials due to its high strength-to-weight ratio, abrasion resistance, and dimensional stability. During long duration space missions, space suits will be subjected to significant amounts of high-energy radiation from several different sources. To insure that pressure garment designs properly account for effects of radiation, it is important to characterize the mechanical changes to structural materials after they have been irradiated. White Sands Test Facility (WSFTF) collaborated with the Crew and Thermal Systems Division at the Johnson Space Center (JSC) to irradiate and test various space suit materials by examining their tensile properties through blunt probe puncture testing and single fiber tensile testing after the materials had been dosed at various levels of simulated GCR and SPE Iron and Proton beams at Brookhaven National Laboratories. The dosages were chosen based on a simulation developed by the Structural Engineering Division at JSC for the expected radiation dosages seen by space suit softgoods seen on a Mars reference mission. Spectra fabric tested in the effort saw equivalent dosages at 2x, 10x, and 20x the predicted dose as well as a simulated 50 year exposure to examine the range of effects on the material and examine whether any degradation due to GCR would be present if the suit softgoods were stored in deep space for a long period of time. This paper presents the results of this work and outlines the impact on space suit pressure garment design for long duration deep space missions.

  4. Microstructure of warm rolling and pearlitic transformation of ultrafine-grained GCr15 steel

    International Nuclear Information System (INIS)

    Sun, Jun-Jie; Lian, Fu-Liang; Liu, Hong-Ji; Jiang, Tao; Guo, Sheng-Wu; Du, Lin-Xiu; Liu, Yong-Ning

    2014-01-01

    Pearlitic transformation mechanisms have been investigated in ultra-fine grained GCr15 steel. The ultrafine-grained steel, whose grain size was less than 1 μm, was prepared by thermo-mechanical treatment at 873 K and then annealing at 923 K for 2 h. Pearlitic transformation was conducted by reheating the ultra-fine grained samples at 1073 K and 1123 K for different periods of time and then cooling in air. Scanning electron microscope observation shows that normal lamellar pearlite, instead of granular cementite and ferrite, cannot be formed when the grain size is approximately less than 4(± 0.6) μm, which yields a critical grain size for normal lamellar pearlitic transformations in this chromium alloyed steel. The result confirms that grain size has a great influence on pearlitic transformation by increasing the diffusion rate of carbon atoms in the ultra-fine grained steel, and the addition of chromium element doesn't change this pearlitic phase transformation rule. Meanwhile, the grain growth rate is reduced by chromium alloying, which is beneficial to form fine grains during austenitizing, thus it facilitating pearlitic transformation by divorced eutectoid transformation. Moreover, chromium element can form a relatively high gradient in the frontier of the undissolved carbide, which promotes carbide formation in the frontier of the undissolved carbide, i.e., chromium promotes divorced eutectoid transformation. - Highlights: • Ultrafine-grained GCr15 steel was obtained by warm rolling and annealing technology. • Reduction of grain size makes pearlite morphology from lamellar to granular. • Adding Cr does not change normal pearlitic phase transformation rule in UFG steel. • Cr carbide resists grain growth and facilitates pearlitic transformation by DET

  5. [Intratubular germ cell neoplasia--review article].

    Science.gov (United States)

    Hes, O; Michal, M; Hora, M

    2007-10-01

    Intratubular germ cell neoplasia is a precursor lesion for germ cell testicular tumors. It is defined as presence of germ cells with abundant vacuolated cytoplasm and large irregular nuclei with nucleoli within seminiferous tubules. The whole morphologic spectrum of intratubular germinal tumors is discussed. Placental alcaline phosphatase, OCT 3/4 can be demonstrated in majority of the cases. Ultrastructural examination does not play a substantial role in differential diagnosis. Gain of chromosome 12p, which is typical for invasive germ cell tumors is absent in pure intratubular germ cell neoplasia. Spermatogonic arrest and rare reactive changes within seminiferous tubuli have to be distinguished from intratubular germ cell neoplasia.

  6. Reprogramming of germ cells into pluripotency

    OpenAIRE

    Sekita, Yoichi; Nakamura, Toshinobu; Kimura, Tohru

    2016-01-01

    Primordial germ cells (PGCs) are precursors of all gametes, and represent the founder cells of the germline. Although developmental potency is restricted to germ-lineage cells, PGCs can be reprogrammed into a pluripotent state. Specifically, PGCs give rise to germ cell tumors, such as testicular teratomas, in vivo, and to pluripotent stem cells known as embryonic germ cells in vitro. In this review, we highlight the current knowledge on signaling pathways, transcriptional controls, and post-t...

  7. Multidimensional representations: The knowledge domain of germs held by students, teachers and medical professionals

    Science.gov (United States)

    Rua, Melissa Jo

    The present study examined the understandings held by 5th, 8th, and 11th-grade students, their teachers and medical professionals about germs. Specifically, this study describes the content and structure of students' and adults' conceptions in the areas of germ contraction, transmission, and treatment of infectious and non-infectious diseases caused by microorganisms. Naturalistic and empirical research methods were used to investigate participants' conceptions. Between and within group similarities were found using data from concept maps on the topic "flu," drawings of germs, a 20 word card sort related to germs and illness, and a semi-structured interview. Concept maps were coded according to techniques by Novak and Gowan (1984). Drawings of germs were coded into four main categories (bacteria, viruses, animal cell, other) and five subcategories (disease, caricature, insect, protozoa, unclassified). Cluster patterns for the card sorts of each group were found using multidimensional scaling techniques. Six coding categories emerged from the interview transcripts: (a) transmission, (b) treatment, (c) effect of weather on illness, (d) immune response, (e) location of germs, and (f) similarities and differences between bacteria and viruses. The findings showed students, teachers and medical professionals have different understandings about bacteria and viruses and the structures of those understandings vary. Gaps or holes in the participants knowledge were found in areas such as: (a) how germs are transmitted, (b) where germs are found, (c) how the body transports and uses medicine, (d) how the immune system functions, (e) the difference between vaccines and non-prescription medicines, (f) differences that exist between bacteria and viruses, and (g) bacterial resistance to medication. The youngest students relied heavily upon personal experiences with germs rather than formal instruction when explaining their conceptions. As a result, the influence of media was

  8. Wheat germ stabilization by infrared radiation.

    Science.gov (United States)

    Gili, Renato D; Palavecino, Pablo M; Cecilia Penci, M; Martinez, Marcela L; Ribotta, Pablo D

    2017-01-01

    Wheat germ has an important enzymatic activity, being lipases the enzymes which cause the highest impact in the reduction of shelf life. The objective of this study was to evaluate the effects of infrared radiation on wheat germ stabilization in an attempt to extend the shelf life. The effects of treatment time, gap (sample distance to IR emitters) and infrared radiation intensity on wheat germ were analyzed through response surface methodology. Final moisture content, final temperature, color of germ and germ oil quality parameters: free fatty acid content changes and total tocopherol content were the responses evaluated using a Box-Behnken design. A combination of an infrared radiation intensity of 4800 W/m 2 , a 3 min treatment and 0.2 m emitter-sample distance were the best processing condition to stabilize the wheat germ without significantly reduction of the tocopherol content. A confirmatory experiment was conducted with these optimal conditions, and the heat-treated and raw germ samples were stored for 90 days at room temperature in three layer packages to protect them against light and oxygen. The oil quality parameters indicated that the raw germ had a shelf-life of about 15 days, with the heat-treated wheat germ maintaining its quality for at least 90 days under these stored conditions.

  9. Role of maternal Xenopus syntabulin in germ plasm aggregation and primordial germ cell specification.

    Science.gov (United States)

    Oh, Denise; Houston, Douglas W

    2017-12-15

    The localization and organization of mitochondria- and ribonucleoprotein granule-rich germ plasm is essential for many aspects of germ cell development. In Xenopus, germ plasm is maternally inherited and is required for the specification of primordial germ cells (PGCs). Germ plasm is aggregated into larger patches during egg activation and cleavage and is ultimately translocated perinuclearly during gastrulation. Although microtubule dynamics and a kinesin (Kif4a) have been implicated in Xenopus germ plasm localization, little is known about how germ plasm distribution is regulated. Here, we identify a role for maternal Xenopus Syntabulin in the aggregation of germ plasm following fertilization. We show that depletion of sybu mRNA using antisense oligonucleotides injected into oocytes results in defects in the aggregation and perinuclear transport of germ plasm and subsequently in reduced PGC numbers. Using live imaging analysis, we also characterize a novel role for Sybu in the collection of germ plasm in vegetal cleavage furrows by surface contraction waves. Additionally, we show that a localized kinesin-like protein, Kif3b, is also required for germ plasm aggregation and that Sybu functionally interacts with Kif3b and Kif4a in germ plasm aggregation. Overall, these data suggest multiple coordinate roles for kinesins and adaptor proteins in controlling the localization and distribution of a cytoplasmic determinant in early development. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Don Germán

    Directory of Open Access Journals (Sweden)

    Juan Luis Mejía

    1991-01-01

    Full Text Available El veranillo de San Juan hace soportable el mediodía. Los "chorros d'oro" inundan de amarillo los antejardines del Prado. Las golondrinas veraneras invaden, al atardecer, los alrededores de la Biblioteca Departamental. Los voceadores de la suerte del paseo Bolívar claman a los cuatro vientos el número que cambiará su destino . Pero algo falta definitivamente en esta Barranquilla. De alguna manera la ciudad ya no es la misma. Falta Don Germán.

  11. Constitutive Modeling of the Flow Stress of GCr15 Continuous Casting Bloom in the Heavy Reduction Process

    Science.gov (United States)

    Ji, Cheng; Wang, Zilin; Wu, Chenhui; Zhu, Miaoyong

    2018-04-01

    According to the calculation results of a 3D thermomechanical-coupled finite-element (FE) model of GCr15 bearing steel bloom during a heavy reduction (HR) process, the variation ranges in the strain rate and strain under HR were described. In addition, the hot deformation behavior of the GCr15 bearing steel was studied over the temperature range from 1023 K to 1573 K (750 °C to 1300 °C) with strain rates of 0.001, 0.01, and 0.1 s-1 in single-pass thermosimulation compression experiments. To ensure the accuracy of the constitutive model, the temperature range was divided into two temperature intervals according to the fully austenitic temperature of GCr15 steel [1173 K (900 °C)]. Two sets of material parameters for the constitutive model were derived based on the true stress-strain curves of the two temperature intervals. A flow stress constitutive model was established using a revised Arrhenius-type constitutive equation, which considers the relationships among the material parameters and true strain. This equation describes dynamic softening during hot compression processes. Considering the effect of glide and climb on the deformation mechanism, the Arrhenius-type constitutive equation was modified by a physically based approach. This model is the most accurate over the temperatures ranging from 1173 K to 1573 K (900 °C to 1300 °C) under HR deformation conditions (ignoring the range from 1273 K to 1573 K (1000 °C to 1300 °C) with a strain rate of 0.1 s-1). To ensure the convergence of the FE calculation, an approximated method was used to estimate the flow stress at temperatures greater than 1573 K (1300 °C).

  12. Treatment Options for Childhood Extracranial Germ Cell Tumors

    Science.gov (United States)

    ... markers . Most malignant germ cell tumors release tumor markers. The following tumor markers are used to detect extracranial germ cell tumors: ... testicular germ cell tumors, blood levels of the tumor markers help show if the tumor is a seminoma ...

  13. General Information about Childhood Extracranial Germ Cell Tumors

    Science.gov (United States)

    ... markers . Most malignant germ cell tumors release tumor markers. The following tumor markers are used to detect extracranial germ cell tumors: ... testicular germ cell tumors, blood levels of the tumor markers help show if the tumor is a seminoma ...

  14. Multiphoton microscopy imaging of developing tooth germs

    Directory of Open Access Journals (Sweden)

    Pei-Yu Pan

    2014-01-01

    Conclusion: In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.

  15. Simulation of a gas cooled reactor with the system code CATHARE

    International Nuclear Information System (INIS)

    Bentivoglio, Fabrice; Ruby, Alain; Geffraye, Genevieve; Messie, Anne; Saez, Manuel; Tauveron, Nicolas; Widlund, Ola

    2006-01-01

    In recent years the CEA has commissioned a wide range of feasibility studies of future advanced nuclear reactors, in particular gas-cooled reactors (GCR). This paper presents an overview of the use of the thermohydraulics code CATHARE in these activities. Extensively validated and qualified for pressurized water reactors, CATHARE has been adapted to deal also with gas-cooled reactor applications. Rather than branching off a separate GCR version of CATHARE, new features have been integrated as independent options in the standard version of the code, respecting the same stringent procedures for documentation and maintenance. CATHARE has evolved into an efficient tool for GCR applications, with first results in good agreement with existing experimental data and other codes. The paper give an example among the studies already carried out with CATHARE with the case of the Very High Temperature Reactor (VHTR) concepts. Current and future activities for experimental validation of CATHARE for GCR applications are also discussed. Short-term validation activities are also included with the assessment of the German utility Oberhausen II. For the long term, CEA has initiated an ambitious experimental program ranging from small scale loops for physical correlations to component technology and system demonstration loops. (authors)

  16. Inner heliosphere spatial gradients of GCR protons and alpha particles in the low GeV range

    Science.gov (United States)

    Gieseler, J.; Boezio, M.; Casolino, M.; De Simone, N.; Di Felice, V.; Heber, B.; Martucci, M.; Picozza, P.

    2013-12-01

    The spacecraft Ulysses was launched in October 1990 in the maximum phase of solar cycle 22, reached its final, highly inclined (80.2°) Keplerian orbit around the Sun in February 1992, and was finally switched off in June 2009. The Kiel Electron Telescope (KET) aboard Ulysses measures electrons from 3 MeV to a few GeV and protons and helium in the energy range from 6 MeV/nucleon to above 2 GeV/nucleon. In order to investigate the radial and latitudinal gradients of galactic cosmic rays (GCR), it is essential to know their intensity variations for a stationary observer in the heliosphere because the Ulysses measurements reflect not only the spatial but also the temporal variation of the energetic particle intensities. This was accomplished in the past with the Interplanetary Monitoring Platform-J (IMP 8) until it was lost in 2006. Fortunately, the satellite-borne experiment PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) was launched in June 2006 and can be used as a reliable 1 AU baseline for measurements of the KET aboard Ulysses. With these tools at hand, we have the opportunity to determine the spatial gradients of GCR protons and alpha particles at about 0.1 to 1 GeV/n in the inner heliosphere during the extended minimum of solar cycle 23. We then compare these A0 cycle.

  17. Germ cell specification and regeneration in planarians.

    Science.gov (United States)

    Newmark, P A; Wang, Y; Chong, T

    2008-01-01

    In metazoans, two apparently distinct mechanisms specify germ cell fate: Determinate specification (observed in animals including Drosophila, Caenorhabditis elegans, zebra fish, and Xenopus) uses cytoplasmic factors localized to specific regions of the egg, whereas epigenetic specification (observed in many basal metazoans, urodeles, and mammals) involves inductive interactions between cells. Much of our understanding of germ cell specification has emerged from studies of model organisms displaying determinate specification. In contrast, our understanding of epigenetic/inductive specification is less advanced and would benefit from studies of additional organisms. Freshwater planarians--widely known for their remarkable powers of regeneration--are well suited for studying the mechanisms by which germ cells can be induced. Classic experiments showed that planarians can regenerate germ cells from body fragments entirely lacking reproductive structures, suggesting that planarian germ cells could be specified by inductive signals. Furthermore, the availability of the genome sequence of the planarian Schmidtea mediterranea, coupled with the animal's susceptibility to systemic RNA interference (RNAi), facilitates functional genomic analyses of germ cell development and regeneration. Here, we describe recent progress in studies of planarian germ cells and frame some of the critical unresolved questions for future work.

  18. Maternal dazap2 Regulates Germ Granules by Counteracting Dynein in Zebrafish Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Meredyth M. Forbes

    2015-07-01

    Full Text Available Primordial germ cells (PGCs are the stem cells of the germline. Generally, germline induction occurs via zygotic factors or the inheritance of maternal determinants called germ plasm (GP. GP is packaged into ribonucleoprotein complexes within oocytes and later promotes the germline fate in embryos. Once PGCs are specified by either mechanism, GP components localize to perinuclear granular-like structures. Although components of zebrafish PGC germ granules have been studied, the maternal factors regulating their assembly and contribution to germ cell development are unknown. Here, we show that the scaffold protein Dazap2 binds to Bucky ball, an essential regulator of oocyte polarity and GP assembly, and colocalizes with the GP in oocytes and in PGCs. Mutational analysis revealed a requirement for maternal Dazap2 (MDazap2 in germ-granule maintenance. Through molecular epistasis analyses, we show that MDazap2 is epistatic to Tdrd7 and maintains germ granules in the embryonic germline by counteracting Dynein activity.

  19. Germ Cell-less Promotes Centrosome Segregation to Induce Germ Cell Formation

    Directory of Open Access Journals (Sweden)

    Dorothy A. Lerit

    2017-01-01

    Full Text Available The primordial germ cells (PGCs specified during embryogenesis serve as progenitors to the adult germline stem cells. In Drosophila, the proper specification and formation of PGCs require both centrosomes and germ plasm, which contains the germline determinants. Centrosomes are microtubule (MT-organizing centers that ensure the faithful segregation of germ plasm into PGCs. To date, mechanisms that modulate centrosome behavior to engineer PGC development have remained elusive. Only one germ plasm component, Germ cell-less (Gcl, is known to play a role in PGC formation. Here, we show that Gcl engineers PGC formation by regulating centrosome dynamics. Loss of gcl leads to aberrant centrosome separation and elaboration of the astral MT network, resulting in inefficient germ plasm segregation and aborted PGC cellularization. Importantly, compromising centrosome separation alone is sufficient to mimic the gcl loss-of-function phenotypes. We conclude Gcl functions as a key regulator of centrosome separation required for proper PGC development.

  20. The Nanos3-3'UTR is required for germ cell specific NANOS3 expression in mouse embryos.

    Directory of Open Access Journals (Sweden)

    Hitomi Suzuki

    Full Text Available BACKGROUND: The regulation of gene expression via a 3' untranslated region (UTR plays essential roles in the discrimination of the germ cell lineage from somatic cells during embryogenesis. This is fundamental to the continuation of a species. Mouse NANOS3 is an essential protein required for the germ cell maintenance and is specifically expressed in these cells. However, the regulatory mechanisms that restrict the expression of this gene in the germ cells is largely unknown at present. METHODOLOGY/PRINCIPAL FINDINGS: In our current study, we show that differences in the stability of Nanos3 mRNA between germ cells and somatic cells is brought about in a 3'UTR-dependent manner in mouse embryos. Although Nanos3 is transcribed in both cell lineages, it is efficiently translated only in the germ lineage. We also find that the translational suppression of NANOS3 in somatic cells is caused by a 3'UTR-mediated mRNA destabilizing mechanism. Surprisingly, even when under the control of the CAG promoter which induces strong ubiquitous transcription in both germ cells and somatic cells, the addition of the Nanos3-3'UTR sequence to the coding region of exogenous gene was effective in restricting protein expression in germ cells. CONCLUSIONS/SIGNIFICANCE: Our current study thus suggests that Nanos3-3'UTR has an essential role in translational control in the mouse embryo.

  1. New evidence for the origin of intracranial germ cell tumours from primordial germ cells

    DEFF Research Database (Denmark)

    Hoei-Hansen, C E; Sehested, A; Juhler, M

    2006-01-01

    Primary intracranial germ cell tumours are rare neoplasms that occur in children and adolescents. This study examined both the biology and the origin of these tumours, as it has been hypothesized that they originate from a totipotent primordial germ cell. We applied recent knowledge from gonadal...... germ cell tumours and analysed expression of a wide panel of stem cell-related proteins (C-KIT, OCT-3/4 (POU5F1), AP-2gamma (TFAP2C), and NANOG) and developmentally regulated germ cell-specific proteins (including MAGE-A4, NY-ESO-1, and TSPY). Expression at the protein level was analysed in 21 children...

  2. Specifying and protecting germ cell fate

    Science.gov (United States)

    Strome, Susan; Updike, Dustin

    2015-01-01

    Germ cells are the special cells in the body that undergo meiosis to generate gametes and subsequently entire new organisms after fertilization, a process that continues generation after generation. Recent studies have expanded our understanding of the factors and mechanisms that specify germ cell fate, including the partitioning of maternally supplied ‘germ plasm’, inheritance of epigenetic memory and expression of transcription factors crucial for primordial germ cell (PGC) development. Even after PGCs are specified, germline fate is labile and thus requires protective mechanisms, such as global transcriptional repression, chromatin state alteration and translation of only germline-appropriate transcripts. Findings from diverse species continue to provide insights into the shared and divergent needs of these special reproductive cells. PMID:26122616

  3. Sex determination in mammalian germ cells

    Directory of Open Access Journals (Sweden)

    Cassy M Spiller

    2015-06-01

    Full Text Available Germ cells are the precursors of the sperm and oocytes and hence are critical for survival of the species. In mammals, they are specified during fetal life, migrate to the developing gonads and then undergo a critical period during which they are instructed, by the soma, to adopt the appropriate sexual fate. In a fetal ovary, germ cells enter meiosis and commit to oogenesis, whereas in a fetal testis, they avoid entry into meiosis and instead undergo mitotic arrest and mature toward spermatogenesis. Here, we discuss what we know so far about the regulation of sex-specific differentiation of germ cells, considering extrinsic molecular cues produced by somatic cells, as well as critical intrinsic changes within the germ cells. This review focuses almost exclusively on our understanding of these events in the mouse model.

  4. Epigenetic reprogramming in the porcine germ line

    DEFF Research Database (Denmark)

    Matzen, Sara Maj Hyldig; Croxall, Nicola; Contreras, David A.

    2011-01-01

    BACKGROUND: Epigenetic reprogramming is critical for genome regulation during germ line development. Genome-wide demethylation in mouse primordial germ cells (PGC) is a unique reprogramming event essential for erasing epigenetic memory and preventing the transmission of epimutations to the next...... an increased proportion of cells in G2. CONCLUSIONS: Our study demonstrates that epigenetic reprogramming occurs in pig migratory and gonadal PGC, and establishes the window of time for the occurrence of these events. Reprogramming of histone H3K9me2 and H3K27me3 detected between E15-E21 precedes the dynamic...... DNA demethylation at imprinted loci and DNA repeats between E22-E42. Our findings demonstrate that major epigenetic reprogramming in the pig germ line follows the overall dynamics shown in mice, suggesting that epigenetic reprogramming of germ cells is conserved in mammals. A better understanding...

  5. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 6: Appendix GCR Volume 1

    International Nuclear Information System (INIS)

    1995-01-01

    The Geological Characterization Report (GCR) for the WIPP site presents, in one document, a compilation of geologic information available to August, 1978, which is judged to be relevant to studies for the WIPP. The Geological Characterization Report for the WIPP site is neither a preliminary safety analysis report nor an environmental impact statement; these documents, when prepared, should be consulted for appropriate discussion of safety analysis and environmental impact. The Geological Characterization Report of the WIPP site is a unique document and at this time is not required by regulatory process. An overview is presented of the purpose of the WIPP, the purpose of the Geological Characterization Report, the site selection criteria, the events leading to studies in New Mexico, status of studies, and the techniques employed during geological characterization

  6. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 6: Appendix GCR Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-31

    The Geological Characterization Report (GCR) for the WIPP site presents, in one document, a compilation of geologic information available to August, 1978, which is judged to be relevant to studies for the WIPP. The Geological Characterization Report for the WIPP site is neither a preliminary safety analysis report nor an environmental impact statement; these documents, when prepared, should be consulted for appropriate discussion of safety analysis and environmental impact. The Geological Characterization Report of the WIPP site is a unique document and at this time is not required by regulatory process. An overview is presented of the purpose of the WIPP, the purpose of the Geological Characterization Report, the site selection criteria, the events leading to studies in New Mexico, status of studies, and the techniques employed during geological characterization.

  7. How to make a primordial germ cell

    OpenAIRE

    Magnúsdóttir, Erna; Surani, M. Azim

    1987-01-01

    Primordial germ cells (PGCs) are the precursors of sperm and eggs, which generate a new organism that is capable of creating endless new generations through germ cells. PGCs are specified during early mammalian postimplantation development, and are uniquely programmed for transmission of genetic and epigenetic information to subsequent generations. In this Primer, we summarise the establishment of the fundamental principles of PGC specification during early development and discuss how it is n...

  8. Dnd knockout ablates germ cells and demonstrates germ cell independent sex differentiation in Atlantic salmon

    NARCIS (Netherlands)

    Wargelius, Anna; Leininger, Sven; Skaftnesmo, Kai Ove; Kleppe, Lene; Andersson, Eva; Taranger, Geir Lasse; Schulz, Rüdiger W; Edvardsen, Rolf B

    2016-01-01

    Introgression of farmed salmon escapees into wild stocks is a major threat to the genetic integrity of wild populations. Using germ cell-free fish in aquaculture may mitigate this problem. Our study investigated whether it is possible to produce germ cell-free salmon in F0 by using CRISPR-Cas9 to

  9. Germ line mechanics – and unfinished business

    Science.gov (United States)

    Wessel, Gary M.

    2016-01-01

    Primordial germ cells are usually made early in the development of an organism. These are the mother of all stem cells that are necessary for propagation of the species, yet use highly diverse mechanisms between organisms. How they are specified, and when and where they form, are central to developmental biology. Using diverse organisms to study this development is illuminating for understanding the mechanics these cells use in this essential function, and for identifying the breadth of evolutionary changes that have occurred between species. This essay emphasizes how echinoderms may contribute to the patch-work quilt of our understanding of germ line formation during embryogenesis. PMID:26970000

  10. Hyaluronan in human deciduous tooth germs in the bell stage. Histochemistry and immunohistochemistry

    DEFF Research Database (Denmark)

    Matthiessen, Martin Ebbe; Garbarsch, Charly; Olsen, Birgitte Engelbrecht

    1997-01-01

    Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry......Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry...

  11. Spatial gradients of GCR protons in the inner heliosphere derived from Ulysses COSPIN/KET and PAMELA measurements

    Science.gov (United States)

    Gieseler, J.; Heber, B.

    2016-05-01

    Context. During the transition from solar cycle 23 to 24 from 2006 to 2009, the Sun was in an unusual solar minimum with very low activity over a long period. These exceptional conditions included a very low interplanetary magnetic field (IMF) strength and a high tilt angle, which both play an important role in the modulation of galactic cosmic rays (GCR) in the heliosphere. Thus, the radial and latitudinal gradients of GCRs are very much expected to depend not only on the solar magnetic epoch, but also on the overall modulation level. Aims: We determine the non-local radial and the latitudinal gradients of protons in the rigidity range from ~0.45 to 2 GV. Methods: This was accomplished by using data from the satellite-borne experiment Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) at Earth and the Kiel Electron Telescope (KET) onboard Ulysses on its highly inclined Keplerian orbit around the Sun with the aphelion at Jupiter's orbit. Results: In comparison to the previous A> 0 solar magnetic epoch, we find that the absolute value of the latitudinal gradient is lower at higher and higher at lower rigidities. This energy dependence is therefore a crucial test for models that describe the cosmic ray transport in the inner heliosphere.

  12. Investigations on femtosecond laser modified micro-textured surface with anti-friction property on bearing steel GCr15

    Science.gov (United States)

    Yang, Lijun; Ding, Ye; Cheng, Bai; He, Jiangtao; Wang, Genwang; Wang, Yang

    2018-03-01

    This work puts forward femtosecond laser modification of micro-textured surface on bearing steel GCr15 in order to reduce frictional wear and enhance load capacity during its application. Multi pulses femtosecond laser ablation experiments are established for the confirmation of laser spot radius as well as single pulse threshold fluence and pulse incubation coefficient of bulk material. Analytical models are set up in combination with hydrodynamics lubrication theory. Corresponding simulations are carried out on to explore influences of surface and cross sectional morphology of textures on hydrodynamics lubrication effect based on Navier-Stokes (N-S) equation. Technological experiments focus on the impacts of femtosecond laser machining variables, like scanning times, scanning velocity, pulse frequency and scanning gap on morphology of grooves as well as realization of optimized textures proposed by simulations, mechanisms of which are analyzed from multiple perspectives. Results of unidirectional rotating friction tests suggest that spherical texture with depth-to-width ratio of 0.2 can significantly improve tribological properties at low loading and velocity condition comparing with un-textured and other textured surfaces, which also verifies the accuracy of simulations and feasibility of femtosecond laser in modification of micro-textured surface.

  13. The effects of microhardnesses and friction coefficients of GCr15 and Cr4Mo4V bearing materials by ion implantation

    International Nuclear Information System (INIS)

    Yang Qifa; Xiang Deguang; Lu Haolin

    1988-01-01

    Some experimental results of microhardnesses and friction coefficients of GCr15 and Cr4Mo4V bearing materials which were implanted with Cr, Mo, N and B ions are reported in this paper. It is found that the microhardnesses are increased and the friction coefficients are reduced by Cr, Mo, N and B ion implantation for two materials. The friction coefficients of Cr + Mo + N , Cr + Mo + B ion implanted samples are reduced to 1/3 of the unimplanted samples

  14. In vitro manganese-dependent cross-talk between Streptococcus mutans VicK and GcrR: implications for overlapping stress response pathways.

    Directory of Open Access Journals (Sweden)

    Jennifer S Downey

    Full Text Available Streptococcus mutans, a major acidogenic component of the dental plaque biofilm, has a key role in caries etiology. Previously, we demonstrated that the VicRK two-component signal transduction system modulates biofilm formation, oxidative stress and acid tolerance responses in S. mutans. Using in vitro phosphorylation assays, here we demonstrate for the first time, that in addition to activating its cognate response regulator protein, the sensor kinase, VicK can transphosphorylate a non-cognate stress regulatory response regulator, GcrR, in the presence of manganese. Manganese is an important micronutrient that has been previously correlated with caries incidence, and which serves as an effector of SloR-mediated metalloregulation in S. mutans. Our findings supporting regulatory effects of manganese on the VicRK, GcrR and SloR, and the cross-regulatory networks formed by these components are more complex than previously appreciated. Using DNaseI footprinting we observed overlapping DNA binding specificities for VicR and GcrR in native promoters, consistent with these proteins being part of the same transcriptional regulon. Our results also support a role for SloR as a positive regulator of the vicRK two component signaling system, since its transcription was drastically reduced in a SloR-deficient mutant. These findings demonstrate the regulatory complexities observed with the S. mutans manganese-dependent response, which involves cross-talk between non-cognate signal transduction systems (VicRK and GcrR to modulate stress response pathways.

  15. Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, E; Jørgensen, N; Brøndum-Nielsen, K

    1998-01-01

    , primordial germ cells, human embryonal carcinoma cells and closely related primate embryonal stem cells reveals various similarities but also differences. We speculate that phenotypical heterogeneity of CIS cells may be associated with their potential to give rise to different tumour types, and may......Clinical observations and epidemiological evidence suggest that important aetiopathological events that cause neoplastic transformation of the male germ cell may occur in fetal life or early infancy. The incidence of germ cell neoplasia is high in individuals with various disorders of gonadal...... hypothesise that if the development of the testis is disturbed or delayed, primordial germ cells or gonocytes undergo maturation delay or differentiation arrest which may render them susceptible to neoplastic transformation. Morphologically homogenous premalignant carcinoma in situ (CIS) cells have...

  16. Molecular basis of tooth germ development

    Czech Academy of Sciences Publication Activity Database

    Fleischmannová, Jana; Krejčí, P.; Matalová, Eva; Míšek, Ivan

    2007-01-01

    Roč. 16, č. 4 (2007), s. 39-46 ISSN 1210-4272 R&D Projects: GA AV ČR KJB500450503; GA MŠk OC B23.001 Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth germ development Subject RIV: FF - HEENT, Dentistry

  17. (K. Schum.) Capuron ex R. Germ. (Sterculiaceae)

    African Journals Online (AJOL)

    Evaluation des caractéristiques ethnobotaniques et structurales de Nesogordonia kabingaensis (K. Schum.) Capuron ex R. Germ. (Sterculiaceae) dans la forêt sacrée d'Ewè au Bénin en vue de la définition des stratégies de sa conservation.

  18. Germ cell neoplasia in situ (GCNIS)

    DEFF Research Database (Denmark)

    Berney, Daniel M; Looijenga, Leendert H J; Idrees, Muhammad

    2016-01-01

    The pre-invasive lesion associated with post-pubertal malignant germ cell tumours of the testis was first recognized in the early 1970s and confirmed by a number of observational and follow-up studies. Until this year, this scientific story has been confused by resistance to the entity and disagr......The pre-invasive lesion associated with post-pubertal malignant germ cell tumours of the testis was first recognized in the early 1970s and confirmed by a number of observational and follow-up studies. Until this year, this scientific story has been confused by resistance to the entity...... and disagreement on its name. Initially termed 'carcinoma in situ' (CIS), it has also been known as 'intratubular germ cell neoplasia, unclassified' (IGCNU) and 'testicular intraepithelial neoplasia' (TIN). In this paper, we review the history of discovery and controversy concerning these names and introduce...... the reasoning for uniting behind a new name, endorsed unanimously at the World Health Organization (WHO) consensus classification 2016: germ cell neoplasia in situ (GCNIS)....

  19. Environmentally induced transgenerational epigenetic reprogramming of primordial germ cells and the subsequent germ line.

    Directory of Open Access Journals (Sweden)

    Michael K Skinner

    Full Text Available A number of environmental factors (e.g. toxicants have been shown to promote the epigenetic transgenerational inheritance of disease and phenotypic variation. Transgenerational inheritance requires the germline transmission of altered epigenetic information between generations in the absence of direct environmental exposures. The primary periods for epigenetic programming of the germ line are those associated with primordial germ cell development and subsequent fetal germline development. The current study examined the actions of an agricultural fungicide vinclozolin on gestating female (F0 generation progeny in regards to the primordial germ cell (PGC epigenetic reprogramming of the F3 generation (i.e. great-grandchildren. The F3 generation germline transcriptome and epigenome (DNA methylation were altered transgenerationally. Interestingly, disruptions in DNA methylation patterns and altered transcriptomes were distinct between germ cells at the onset of gonadal sex determination at embryonic day 13 (E13 and after cord formation in the testis at embryonic day 16 (E16. A larger number of DNA methylation abnormalities (epimutations and transcriptional alterations were observed in the E13 germ cells than in the E16 germ cells. These observations indicate that altered transgenerational epigenetic reprogramming and function of the male germline is a component of vinclozolin induced epigenetic transgenerational inheritance of disease. Insights into the molecular control of germline transmitted epigenetic inheritance are provided.

  20. The Biology of the Germ line in Echinoderms

    Science.gov (United States)

    Wessel, Gary M.; Brayboy, Lynae; Fresques, Tara; Gustafson, Eric A.; Oulhen, Nathalie; Ramos, Isabela; Reich, Adrian; Swartz, S. Zachary; Yajima, Mamiko; Zazueta, Vanessa

    2014-01-01

    SUMMARY The formation of the germ line in an embryo marks a fresh round of reproductive potential. The developmental stage and location within the embryo where the primordial germ cells (PGCs) form, however, differs markedly among species. In many animals, the germ line is formed by an inherited mechanism, in which molecules made and selectively partitioned within the oocyte drive the early development of cells that acquire this material to a germ-line fate. In contrast, the germ line of other animals is fated by an inductive mechanism that involves signaling between cells that directs this specialized fate. In this review, we explore the mechanisms of germ-line determination in echinoderms, an early-branching sister group to the chordates. One member of the phylum, sea urchins, appears to use an inherited mechanism of germ-line formation, whereas their relatives, the sea stars, appear to use an inductive mechanism. We first integrate the experimental results currently available for germ line determination in the sea urchin, for which considerable new information is available, and then broaden the investigation to the lesser-known mechanisms in sea stars and other echinoderms. Even with this limited insight, it appears that sea stars, and perhaps the majority of the echinoderm taxon, rely on inductive mechanisms for germ-line fate determination. This enables a strongly contrasted picture for germ-line determination in this phylum, but one for which transitions between different modes of germ-line determination might now be experimentally addressed. PMID:23900765

  1. Molecular biology of testicular germ cell tumors.

    Science.gov (United States)

    Gonzalez-Exposito, R; Merino, M; Aguayo, C

    2016-06-01

    Testicular germ cell tumors (TGCTs) are the most common solid tumors in young adult men. They constitute a unique pathology because of their embryonic and germ origin and their special behavior. Genetic predisposition, environmental factors involved in their development and genetic aberrations have been under study in many works throughout the last years trying to explain the susceptibility and the transformation mechanism of TGCTs. Despite the high rate of cure in this type of tumors because its particular sensitivity to cisplatin, there are tumors resistant to chemotherapy for which it is needed to find new therapies. In the present work, it has been carried out a literature review on the most important molecular aspects involved in the onset and development of such tumors, as well as a review of the major developments regarding prognostic factors, new prognostic biomarkers and the possibility of new targeted therapies.

  2. Radiation Therapy of Suprasellar Germ Cell Tumors

    International Nuclear Information System (INIS)

    Park, Woo Yoon; Choi, Doo Ho; Choi, Eun Kyung; Kim, Il Han; Ha, Sung Whan; Park, Charn Il

    1988-01-01

    A retrospective study was performed on 15 patients with suprasellar germ cell tumors treated by megavoltage external beam irradiation between Feb. 1979 and Dec. 1985. Follow-up period of survivors was 30 to 91 months. Histologic diagnosis was obtained before radiation therapy in 10 patients (9 germinomas and 1 mixed). Five patients were treated without histologic verification. In 9 patients with biopsy-proven germinomas radiation therapy was delivered to the craniospinal axis in 6, to the whole brain in 3. In 5 patients with mixed germ cell tumor or elevated tumor marker, irradiation was delivered to the craniospinal axis in 2, to the whole brain in 2, and to the primary site only in 1. Total doses ranged from 5,000 to 5,500 cGy to the primary site, 3,000 to 4,400 cGy to the whole brain, and 1,300 to 3,000 cGy to the spine. In these 14, local tumor was controlled and primary or spinal failure was not observed. One patient without elevated tumor marker was treated to the whole brain, The tumor was not controlled and he had spinal recurrence. It is proven that radiation therapy is an effective treatment for suprasellar germ cell tumors. The neuroendocrinologic presentation, tumor marker status, early response to radiation measured on CT seem to be useful means for selecting patients for radiation therapy when tissue diagnosis is not available

  3. Germ line mutations associated with leukemias.

    Science.gov (United States)

    Porter, Christopher C

    2016-12-02

    Several genetic syndromes have long been associated with a predisposition to the development of leukemia, including bone marrow failure syndromes, Down syndrome, and Li Fraumeni syndrome. Recent work has better defined the leukemia risk and outcomes in these syndromes. Also, in the last several years, a number of other germ line mutations have been discovered to define new leukemia predisposition syndromes, including ANKRD26, GATA2, PAX5, ETV6, and DDX41 In addition, data suggest that a substantial proportion of patients with therapy related leukemias harbor germ line mutations in DNA damage response genes such as BRCA1/2 and TP53 Recognition of clinical associations, acquisition of a thorough family history, and high index-of-suspicion are critical in the diagnosis of these leukemia predisposition syndromes. Accurate identification of patients with germ line mutations associated with leukemia can have important clinical implications as it relates to management of the leukemia, as well as genetic counseling of family members. © 2016 by The American Society of Hematology. All rights reserved.

  4. Convergent evolution of germ granule nucleators: A hypothesis.

    Science.gov (United States)

    Kulkarni, Arpita; Extavour, Cassandra G

    2017-10-01

    Germ cells have been considered "the ultimate stem cell" because they alone, during normal development of sexually reproducing organisms, are able to give rise to all organismal cell types. Morphological descriptions of a specialized cytoplasm termed 'germ plasm' and associated electron dense ribonucleoprotein (RNP) structures called 'germ granules' within germ cells date back as early as the 1800s. Both germ plasm and germ granules are implicated in germ line specification across metazoans. However, at a molecular level, little is currently understood about the molecular mechanisms that assemble these entities in germ cells. The discovery that in some animals, the gene products of a small number of lineage-specific genes initiate the assembly (also termed nucleation) of germ granules and/or germ plasm is the first step towards facilitating a better understanding of these complex biological processes. Here, we draw on research spanning over 100years that supports the hypothesis that these nucleator genes may have evolved convergently, allowing them to perform analogous roles across animal lineages. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Understanding Mammalian Germ Line Development with In Vitro Models.

    Science.gov (United States)

    Martínez-Arroyo, Ana M; Míguez-Forján, Jose M; Remohí, Jose; Pellicer, Antonio; Medrano, Jose V

    2015-09-15

    Germ line development is crucial in organisms with sexual reproduction to complete their life cycle. In mammals, knowledge about germ line development is based mainly on the mouse model, in which genetic and epigenetic events are well described. However, little is known about how germ line development is orchestrated in humans, especially in the earliest stages. New findings derived from human in vitro models to obtain germ cells can shed light on these questions. This comprehensive review summarizes the current knowledge about mammalian germ line development, emphasizing the state of the art obtained from in vitro models for germ cell-like cell derivation. Current knowledge of the pluripotency cycle and germ cell specification has allowed different in vitro strategies to obtain germ cells with proven functionality in mouse models. Several reports during the last 10 years show that in vitro germ cell derivation with proven functionality to generate a healthy offspring is possible in mice. However, differences in the embryo development and pluripotency potential between human and mouse make it difficult to extrapolate these results. Further efforts on both human and mouse in vitro models to obtain germ cells from pluripotent stem cells may help to elucidate how human physiological events take place; therefore, therapeutic strategies can also be considered.

  6. Co-culture of Mouse Embryonic Stem Cells with Sertoli Cells Promote in vitro Generation of Germ Cells

    Directory of Open Access Journals (Sweden)

    Mohammad Miryounesi

    2013-06-01

    Full Text Available   Objective(s: Sertoli cells support in vivo germ cell production; but, its exact mechanism has not been well understood. The present study was designed to analyze the effect of Sertoli cells in differentiation of mouse embryonic stem cells (mESCs to germ cells.   Materials and Methods: A fusion construct composed of a Stra8 gene promoter and the coding region of enhanced green fluorescence protein was produced to select differentiated mESCs. To analyze sertoli cells’ effect in differentiation process, mESCs were separated into two groups: the first group was cultured on gelatin with retinoic acid treatment and the second group was co-cultured with sertoli cell feeder without retinoic acid induction. Expressions of pre-meiotic (Stra8, meiotic (Dazl and Sycp3 and post-meiotic (Prm1 genes were evaluated at different differentiation stages (+7, +12 and +18 days of culture. Results: In the first group, expressions of meiotic and post-meiotic genes started 12 and 18 days after induction with retinoic acid, respectively. In the second group, 7 days after co-culturing with Sertoli cells, expression of meiotic and post-meiotic genes was observed. Conclusion: These results show that differentiation process to germ cells is supported by Sertoli cells. Our findings provide a novel effective approach for generation of germ cell in vitro and studying the interaction of germ cells with their niche.

  7. Lipase inactivation in wheat germ by gamma irradiation

    International Nuclear Information System (INIS)

    Jha, Pankaj Kumar; Kudachikar, V.B.; Kumar, Sourav

    2013-01-01

    An attempt was made to improve the shelf life of wheat germ by optimizing processing conditions involving γ-irradiation. Studies were carried out to investigate the effect of γ-irradiation (0–30 kGy doses) on the chemical composition of wheat germ with respect to variation in moisture, total ash, crude fat, free fatty acid, protein and lipase activity. The results demonstrate that shelf stability of wheat germ was achieved by inactivation of lipase at doses of γ-irradiation greater than 12 kGy. - Highlights: Ø γ-irradiation was found to inactivate Lipase present in Wheat Germ. Ø The treatment did not result in significant changes in Total Ash, Moisture and Protein Content of Wheat Germ. Ø The irradiation at 30 kGy resulted in 31.2 % inactivation of Lipase in Wheat Germ

  8. Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, E; Jørgensen, N; Brøndum-Nielsen, K

    1998-01-01

    Clinical observations and epidemiological evidence suggest that important aetiopathological events that cause neoplastic transformation of the male germ cell may occur in fetal life or early infancy. The incidence of germ cell neoplasia is high in individuals with various disorders of gonadal...... frequency mosaicism XY/XO) which can also be found in patients with testicular cancer. The variety of conditions that predispose to testicular neoplasia and the rise in its incidence in many countries speaks for the influence of environmental factors which may affect genetically predisposed individuals. We...

  9. Germ tube-specific antigens of Candida albicans cell walls

    International Nuclear Information System (INIS)

    Sundstrom, P.R.

    1986-01-01

    Studies were performed to characterize the surface differences between blastospores and germ tubes of the pathogenic, dimorphic yeast, Candida albicans, and to identify components of yeast cells responsible for these differences. Investigation of surfaces differences of the two growth forms was facilitated by the production of rabbit antiserum prepared against Formalin-treated yeast possessing germ tubes. To prepare antiserum specific for germ tubes, this serum was adsorbed with stationary phase blastospores. Whereas the unadsorbed antiserum reacted with both blastospore and germ tube forms by immunofluorescence and Enzyme-Linked Immunosorbent Assay, the adsorbed antiserum did not react with blastospores but detected germ tube-specific antigens in hyphal forms. The differences between blastospores and germ tubes of Candida albicans, were further studied by comparing enzymatic digests of cell walls of both growth forms in radiolabeled organisms. Organisms were labeled either on the surface with 125 I, or metabolically with [ 35 S] methionine or [ 3 H] mannose. Three-surface-located components (as shown by antibody adsorption and elution experiments) were precipitated from Zymolase digests. All three components were mannoproteins as shown by their ability to bind Concanavalin A, and to be labeled in protein labeling procedures, and two of these (200,000 and 155,000 molecular weight) were germ tube specific, as shown by their ability to be precipitated by germ tube-specific antiserum. Monoclonal antibodies were prepared to C. albicans, using blastospores bearing germ tubes as immunogen

  10. Mixed germ cell tumors: Report of two cases

    Directory of Open Access Journals (Sweden)

    Pradhan M Pagaro

    2013-01-01

    Full Text Available Germ cell tumors arise in the ovaries and testis and rarely in other tissues. Mixed germ cell tumors are rare. We report two cases of mixed germ cell tumors, one consisting of seminoma and immature teratoma in the testis of a 30-year-old male and second consisting of a yolk sac tumor and immature teratoma in the ovary of a 17-year-old female. Many combinations of mixed germ cell tumors have been reported but very few cases of the above-mentioned combinations have been reported in literature.

  11. Topology of the germ plasm and development of primordial germ cells in inverted amphibian eggs

    Science.gov (United States)

    Wakahara, M.; Neff, A. W.; Malacinski, G. M.

    1984-01-01

    Inverted Xenopus eggs have reduced numbers of primordial germ cells (PGCs). The extent of the reduction varies from spawning to spawning. Histologic examination revealed that PGC counts were lowest in inverted eggs which displayed the greatest amount of shift in the vegetal mass of large yolk platelets, although the germ plasm itself always remained localized in the egg's original vegetal hemisphere. Even at blastulation the germ plasm continued to be localized in the egg's original vegetal hemisphere. In many cases, however, it was confined to the periphery of the embryo, which probably accounts for the reduced PGC number in some tadpoles. In other cases it may have been dispersed and therefore not detectable in histologic analyses. Although the altered site of involution in inverted embryos did not influence PGC development, subsequent cell movement patterns apparently did. Those embryos which displayed the largest degree of pattern reversal at the tail-bud stage also exhibited the most extreme reduction in PGC numbers. A brief cold shock (4 degrees C, 10 min) prior to first cleavage leads to a further reduction in PGC numbers in inverted embryos, probably as a result of the displacement of the germ plasm away from its original vegetal pole location.

  12. Epigenetic features of testicular germ cell tumours in relation to epigenetic characteristics of foetal germ cells

    DEFF Research Database (Denmark)

    Kristensen, Dina Graae; Skakkebæk, Niels E; Rajpert-De Meyts, Ewa

    2013-01-01

    Foetal development of germ cells is a unique biological process orchestrated by cellular specification, migration and niche development in concert with extensive epigenetic and transcriptional programs. Many of these processes take place early in foetal life and are hence very difficult to study ...

  13. Gene manipulation: churches against germ changes.

    Science.gov (United States)

    Budiansky, S

    An immediate ban on human genetic engineering that alters germ cells is called for in a resolution, written by activist Jeremy Rifkin, that was released last week over the signatures of 21 Catholic bishops, a broad spectrum of Protestant and Jewish religious leaders, and three scientists. The resolution takes a much harder line than was espoused by religious leaders in a letter to the now-defunct President's Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioral Research. Several of the signers indicated that they did not fully agree with the resolution, but saw it as a good vehicle to encourage public discussion.

  14. The fascinating germ theories on cancer pathogenesis.

    Science.gov (United States)

    Tsoucalas, G; Laios, K; Karamanou, M; Gennimata, V; Androutsos, G

    2014-01-01

    For more than 100 years, the germ theory of cancer, proposing that microorganisms were at the origin of the disease, dominated medicine. Several eminent scientists like Etienne Burnet, Mikhail Stepanovich Voronin, Charles-Louis Malassez, and Francis-Peyton Rous argued on the pathogenesis presenting their theories that implicated cocci, fungi and parasites. The impact of these theories was culminated by the Nobel Prize in 1926 that was attributed to the Danish scientist Johannes Fibiger for his work on the nematode Spiroptera as a causative agent in cancer. Even if those theories were the result of fantasy and misinterpretation, they paved the way for the scientific research in oncology.

  15. openQ*D simulation code for QCD+QED

    Science.gov (United States)

    Campos, Isabel; Fritzsch, Patrick; Hansen, Martin; Krstić Marinković, Marina; Patella, Agostino; Ramos, Alberto; Tantalo, Nazario

    2018-03-01

    The openQ*D code for the simulation of QCD+QED with C* boundary conditions is presented. This code is based on openQCD-1.6, from which it inherits the core features that ensure its efficiency: the locally-deflated SAP-preconditioned GCR solver, the twisted-mass frequency splitting of the fermion action, the multilevel integrator, the 4th order OMF integrator, the SSE/AVX intrinsics, etc. The photon field is treated as fully dynamical and C* boundary conditions can be chosen in the spatial directions. We discuss the main features of openQ*D, and we show basic test results and performance analysis. An alpha version of this code is publicly available and can be downloaded from http://rcstar.web.cern.ch/.

  16. Critical Function of PRDM2 in the Neoplastic Growth of Testicular Germ Cell Tumors

    Directory of Open Access Journals (Sweden)

    Erika Di Zazzo

    2016-12-01

    Full Text Available Testicular germ cell tumors (TGCTs derive from primordial germ cells. Their maturation is blocked at different stages, reflecting histological tumor subtypes. A common genetic alteration in TGCT is a deletion of the chromosome 1 short arm, where the PRDM2 gene, belonging to the Positive Regulatory domain gene (PRDM family, is located. Expression of PRDM2 gene is shifted in different human tumors, where the expression of the two principal protein forms coded by PRDM2 gene, RIZ1 and RIZ2, is frequently unbalanced. Therefore, PRDM2 is actually considered a candidate tumor suppressor gene in different types of cancer. Although recent studies have demonstrated that PRDM gene family members have a pivotal role during the early stages of testicular development, no information are actually available on the involvement of these genes in TGCTs. In this article we show by qRT-PCR analysis that PRDM2 expression level is modulated by proliferation and differentiation agents such as estradiol, whose exposure during fetal life is probably an important risk factor for TGCTs development in adulthood. Furthermore in normal and cancer germ cell lines, PRDM2 binds estradiol receptor α (ERα and influences proliferation, survival and apoptosis, as previously reported using MCF-7 breast cancer cell line, suggesting a potential tumor-suppressor role in TGCT formation.

  17. How to make a human germ cell

    Directory of Open Access Journals (Sweden)

    Paul S Cooke

    2015-06-01

    Full Text Available How the primordial germ cell (PGC lineage, which eventually gives rise to spermatozoa in males and oocytes in females, is established in the developing mammalian embryo has been a critical topic in both developmental and reproductive biology for many years. There have been significant breakthroughs over the past two decades in establishing both the source of PGCs and the factors that regulate the specification of this lineage in mice, [1] but our understanding of the factors that control PGC development in the human is rudimentary. The SRY-related HMG-box (SOX family of transcription factors consists of 20 genes in humans and mice that are involved in the maintenance of pluripotency, male sexual development, and other processes. A recent paper in Cell has identified one member of this family, SOX17, as an essential factor for inducing the PGC lineage in humans. [2] Surprisingly, this protein does not appear to have a role in PGC specification in mice. This work not only introduces a new and important player to the field of germ cell specification, but also emphasizes the uniqueness of human PGC development compared to more extensively studied mouse models.

  18. Intestinal obstruction in germ-free dogs.

    Science.gov (United States)

    Heneghan, J B; Robinson, J W; Menge, H; Winistörfer, B

    1981-08-01

    Mechanical occlusions were created in the intestines of four germ-free dogs. At the time of the operation, a control loop of mid-intestine was perfused in vivo and then excised for examinations in vitro, which included the determination of the equilibrium uptake of phenylalanine and of beta-methyl-glucoside, the influx kinetics of phenylalanine and morphometric analysis of the mucosa by microdissection and stereological techniques. Seven days after establishment of the occlusion the abdomen was reopened, and loops above and below the occlusion were perfused, and then excised for the same tests in vitro. Unlike occluded loops of conventional dogs, the intestine of the germ-free animal above the occlusion does not secrete water and electrolytes into the lumen. Its transport properties in vitro do not differ from those of the control loop, and the morphometric analyses reveal only slight changes in villus structure. The loop below the obstruction undergoes marked atrophy, as has been observed in conventional dogs. The results suggest that the copious secretion that occurs above an intestinal obstruction in normal animals is due to the presence of an abundant bacterial population in the obstruction fluid.

  19. The Formation of Germ Cell for Organizational Learning

    Science.gov (United States)

    Ivaldi, Silvia; Scaratti, Giuseppe

    2016-01-01

    Purpose: The aim of the paper is to analyze the process of "germ cell" formation by framing it as an opportunity for promoting organizational learning and transformation. The paper aims to specifically answer two research questions: Why does the "germ cell" have a pivotal role in organization's transformation? and Which…

  20. Germ cell transplantation in an azoospermic Klinefelter bull.

    Science.gov (United States)

    Joerg, Hannes; Janett, Fredi; Schlatt, Stefan; Mueller, Simone; Graphodatskaya, Daria; Suwattana, Duangsmorn; Asai, Mika; Stranzinger, Gerald

    2003-12-01

    Germ cell transplantation is a technique that transfers donor testicular cells into recipient testes. A population of germ cells can colonize the recipient testis, initiate spermatogenesis, and produce sperm capable of fertilization. In the present study, a nonmosaic Klinefelter bull was used as a germ cell recipient. The donor cell suspension was introduced into the rete testis using ultrasound-guided puncture. A pulsatile administration of GnRH was performed to stimulate spermatogenesis. The molecular approach to detect donor cells was done by a quantitative polymerase chain reaction with allele discrimination based on a genetic mutation between donor and recipient. Therefore, a known genetic mutation, associated with coat-color phenotype, was used to calculate the ratio of donor to recipient cells in the biopsy specimens and ejaculates for 10 mo. After slaughtering, meiotic preparations were performed. The injected germ cells did not undergo spermatogenesis. Six months after germ cell transplantation, the donor cells were rejected, which indicates that the donor cells could not incorporate in the testis. The hormone stimulation showed that the testosterone-producing Leydig cells were functionally intact. Despite subfertility therapy, neither the recipient nor the donor cells underwent spermatogenesis. Therefore, nonmosaic Klinefelter bulls are not suitable as germ cell recipients. Future germ cell recipients in cattle could be mosaic Klinefelters, interspecies hybrids, bulls with Sertoli cell-only syndrome, or bulls with disrupted germ cell migration caused by RNA interference.

  1. Two-Dimensional Identification of Fetal Tooth Germs.

    Science.gov (United States)

    Seabra, Mariana; Vaz, Paula; Valente, Francisco; Braga, Ana; Felino, António

    2017-03-01

      To demonstrate the efficiency and applicability of two-dimensional ultrasonography in the identification of tooth germs and in the assessment of potential pathology.   Observational, descriptive, cross-sectional study.   Prenatal Diagnosis Unit of Centro Hospitalar de Vila Nova de Gaia / Espinho-Empresa Pública in Portugal.   A total of 157 white pregnant women (median age, 32 years; range, 14 to 47 years) undergoing routine ultrasound exams.   Description of the fetal tooth germs, as visualized by two-dimensional ultrasonography, including results from prior fetal biometry and detailed screening for malformations.   In the first trimester group, ultrasonography identified 10 tooth germs in the maxilla and 10 tooth germs in the mandible in all fetuses except for one who presented eight maxillary tooth germs. This case was associated with a chromosomal abnormality (trisomy 13) with a bilateral cleft palate. In the second and third trimesters group, ultrasonography identified a larger range of tooth germs: 81.2% of fetuses showed 10 tooth germs in the maxilla and 85.0% of fetuses had 10 tooth germs in the mandible. Hypodontia was more prevalent in the maxilla than in the mandible, which led us to use qualitative two-dimensional ultrasonography to analyze the possible association between hypodontia and other variables such as fetal pathology, markers, head, nuchal, face, and spine.   We recommend using this method as the first exam to evaluate fetal morphology and also to help establish accurate diagnosis of abnormalities in pregnancy.

  2. Is Tobacco Smoke a Germ-Cell Mutagen?

    Science.gov (United States)

    Although no international organization exists to declare whether an agent is a germ-cell mutagen, tobacco smoke may be a human germ-cell mutagen. In the mouse, tobacco smoke induces a significant increase in the mutation frequency at an expanded simple tandem repeat (ESTR) locus....

  3. Cytogenetics of testicular germ cell tumors of adults

    NARCIS (Netherlands)

    van Echten, J; de Jong, B

    1998-01-01

    In this article, not intended to be a review of the literature, we present our view about the oncogenesis, pathogenesis and tumor progression of testicular germ cell tumors of adults. This view is based on our cytogenetic analyses df primary testicular germ cell tumors (seminomas and non-seminomas),

  4. Primordial germ cells and amnion development in the avian embryo

    NARCIS (Netherlands)

    De Melo Bernardo, Ana

    2016-01-01

    Primordial germ cells (PGCs) are the progenitors of the gametes, responsible for transmitting genetic information from generation to generation. Although there is a long history of gamete biology research, there is still a lot to be learned about many of the mechanisms underlying germ cell

  5. Localization of germ plasm-related structures during sea urchin oogenesis.

    Science.gov (United States)

    Yakovlev, Konstantin V

    2016-01-01

    Animal germ cells have specific organelles that are similar to ribonucleoprotein complex, called germ plasm, which is accumulated in eggs. Germ plasm is essential for inherited mechanism of germ line segregation in early embryogenesis. Sea urchins have early germ line segregation in early embryogenesis. Nevertheless, organization of germ plasm-related organelles and their molecular composition are still unclear. Another issue is whether maternally accumulated germ plasm exists in the sea urchin eggs. I analyzed intracellular localization of germ plasm during oogenesis in sea urchin Strongylocentrotus intermedius by using morphological approach and immunocytochemical detection of Vasa, a germ plasm marker. All ovarian germ cells have germ plasm-related organelles in the form of germ granules, Balbiani bodies, and perinuclear nuage found previously in germ cells in other animals. Maternal germ plasm is accumulated in late oogenesis at the cell periphery. Cytoskeletal drug treatment showed an association of Vasa-positive granules with actin filaments in the egg cortex. All female germ cells of sea urchins have germ plasm-related organelles. Eggs have a maternally accumulated germ plasm associated with cortical cytoskeleton. These findings correlate with early segregation of germ line in sea urchins. © 2015 Wiley Periodicals, Inc.

  6. Progress in gene transfer by germ cells in mammals.

    Science.gov (United States)

    Niu, Yidong; Liang, Shulong

    2008-12-01

    Use of germ cells as vectors for transgenesis in mammals has been well developed and offers exciting prospects for experimental and applied biology, agricultural and medical sciences. Such approach is referred to as either male germ cell mediated gene transfer (MGCMGT) or female germ cell mediated gene transfer (FGCMGT) technique. Sperm-mediated gene transfer (SMGT), including its alternative method, testis-mediated gene transfer (TMGT), becomes an established and reliable method for transgenesis. They have been extensively used for producing transgenic animals. The newly developed approach of FGCMGT, ovary-mediated gene transfer (OMGT) is also a novel and useful tool for efficient transgenesis. This review highlights an overview of the recent progress in germ cell mediated gene transfer techniques, methods developed and mechanisms of nucleic acid uptake by germ cells.

  7. Origin and development of the germ line in sea stars

    Science.gov (United States)

    Wessel, Gary M.; Fresques, Tara; Kiyomoto, Masato; Yajima, Mamiko; Zazueta, Vanesa

    2014-01-01

    This review summarizes and integrates our current understanding of how sea stars make gametes. Although little is known of the mechanism of germ line formation in these animals, recent results point to specific cells and to cohorts of molecules in the embryos and larvae that may lay the ground work for future research efforts. A coelomic outpocketing forms in the posterior of the gut in larvae, referred to as the posterior enterocoel (PE), that when removed, significantly reduces the number of germ cell later in larval growth. This same PE structure also selectively accumulates several germ-line associated factors – vasa, nanos, piwi – and excludes factors involved in somatic cell fate. Since its formation is relatively late in development, these germ cells may form by inductive mechanisms. When integrated into the morphological observations of germ cells and gonad development in larvae, juveniles, and adults, the field of germ line determination appears to have a good model system to study inductive germ line determination to complement the recent work on the molecular mechanisms in mice. We hope this review will also guide investigators interested in germ line determination and regulation of the germ line in how these animals can help in this research field. The review is not intended to be comprehensive – sea star reproduction has been studied over 100 years and many reviews are comprehensive in their coverage of, for example, seasonal growth of the gonads in response to light, nutrient, and temperature. Rather the intent of this review is to help the reader focus on new experimental results attached to the historical underpinnings of how the germ cell functions in sea stars with particular emphasis to clarify the important areas of priority for future research. PMID:24648114

  8. Germ tube growth of Candida albicans.

    Science.gov (United States)

    Gow, N A

    1997-12-01

    The clinical pathogen Candida albicans is a budding yeast that is capable of forming a range of polarized and expanded cell shapes from pseudohyphae to true nonconstricted hyphae. Filamentous forms consist of contiguous uninucleated compartments that are partitioned by septa. It has long been held that the so-called "dimorphic transition" from a budding to a filamentous form may aid the fungus to penetrate epithelia and may therefore be a virulence factor. This review summarized new information regarding the physiology and ecology of hyphal growth in C. albicans. New evidence has demonstrated that hyphae of C. albicans have a sense of touch so that they grow along grooves and through pores (thigmotropism). This may aid infiltration of epithelial surfaces during tissue invasion. Hyphae are also aerotropic and can form helices when contacting solid surfaces. Growing evidence supports the view that hyphal growth is a response to nutrient deprivation, especially low nitrogen and that filamentous growth enables the fungus to forage for nutrients more effectively. Further insights into the growth of C. albicans have come from the analysis of genes and mutations of Saccharomyces which have begun to reveal the molecular mechanisms underlying the mechanisms of bud site selection, cell polarity and signal transduction pathways that lead to pseudohyphal development in this and other organisms. For example, it is now clear that a MAP-kinase cascade, homologous to the mating pathway in Saccharomyces, regulates filamentous growth in both fungi. However, this must be only one of several overlapping or separate signal transduction pathways for hyphal development because filamentous growth still occurs in mutants of Candida and Saccharomyces which are blocked in this pathway. Cell cycle analyses have shown that hyphal phase cell cycle of Candida is distinct from that in budding and pseudohyphal formation and so pseudohyphal growth of Saccharomyces is not a true model of germ tube

  9. Developmental Competence for Primordial Germ Cell Fate.

    Science.gov (United States)

    Günesdogan, Ufuk; Surani, M Azim

    2016-01-01

    During mammalian embryonic development, the trophectoderm and primitive endoderm give rise to extraembryonic tissues, while the epiblast differentiates into all somatic lineages and the germline. Remarkably, only a few classes of signaling pathways induce the differentiation of these progenitor cells into diverse lineages. Accordingly, the functional outcome of a particular signal depends on the developmental competence of the target cells. Thus, developmental competence can be defined as the ability of a cell to integrate intrinsic and extrinsic cues to execute a specific developmental program toward a specific cell fate. Downstream of signaling, there is the combinatorial activity of transcription factors and their cofactors, which is modulated by the chromatin state of the target cells. Here, we discuss the concept of developmental competence, and the factors that regulate this state with reference to the specification of mammalian primordial germ cells. © 2016 Elsevier Inc. All rights reserved.

  10. MRI of intracranial germ cell tumours

    International Nuclear Information System (INIS)

    Sumida, M.; Uozumi, T.; Kiya, K.; Mukada, K.; Arita, K.; Kurisu, K.; Sugiyama, K.; Onda, J.; Satoh, H.; Ikawa, F.; Migita, K.

    1995-01-01

    We reviewed MRI findings in proven intracranial germ cell tumours in 22 cases, 12 of whom received Gd-DTPA. On T1-weighted images, the signal intensity of the tumour parenchyma was moderately low in 19 cases and isointense in 3; on T2-weighted images, it was high in all cases. Regions of different intensity thought to be cysts were found in 17 (77 %): 7 of 12 patients with germinoma (58 %) and in all other cases. Of the 13 patients with pineal lesions T1-weighted sagittal images showed the aqueduct to be obstructed in 5, stenotic in 7 and normal in 1. Strong contrast enhancement was observed in all 12 cases. Of the 14 patients with suprasellar lesions, 5 were found to have an intrasellar extension, and in 3 of these, the normal pituitary gland, which could be distinguished from the tumour, was displaced anteriorly. Ten patients (45 %) had multiple lesions. (orig.)

  11. US/FRG umbrella agreement for cooperation in GCR Development. Fuel, fission products, and graphite subprogram. Quarterly status report, July 1, 1982-September 30, 1982

    International Nuclear Information System (INIS)

    Turner, R.F.

    1982-10-01

    This report describes the status of the cooperative work being performed in the Fuel, Fission Product, and Graphite Subprogram under the HTR-Implementing Agreement of the United States/Federal Republic of Germany Umbrella Agreement for Cooperation in GCR Development. The status is described relative to the commitments in the Subprogram Plan for Fuel, Fission Products, and Graphite, Revision 5, April 1982. The work described was performed during the period July 1, 1982 through September 30, 1982 in the HTGR Base Technology Program at Oak Ridge National Laboratory, the HTGR Fuel and Plant Technology Programs at General Atomic Company (GA), and the Project HTR-Brennstoffkreislauf of the Entwicklungsgemeinschaft HTR at KFA Julich, HRB Mannheim, HOBEG Hanau, and SIGRI Meitingen. The requirement for and format of this quarterly status report are specified in the HTR Implementing Agreement procedures for cooperation. Responsibility for preparation of the quarterly report alternates between GA and KFA

  12. Identification of Primordial Germ Cells: Cytological, Histological and Immunohistochemical Aspects

    Directory of Open Access Journals (Sweden)

    Nazan Deniz Yön

    2015-04-01

    Full Text Available Primordial germ cells (PGCs constitute an embryonic cell type that migrate to gonadal precursors and form the gametes. In many animals, PGCs are set apart from somatic cells early during embryogenesis. These cells migrate to gonadal precursors and then constitute gonads so they are useful models for cell motility studies. They have a highlighted importance for development and reproduction studies. Primordial germ cells have morphological differences from the somatic cells. Structure of these cells can be detected with light and electron microscopy in early development stages. This review describes the morphological, histological, molecular and ultrastructural features of primordial germ cells in different animals and gives an overview for simplified identification.

  13. DAZL limits pluripotency, differentiation, and apoptosis in developing primordial germ cells

    NARCIS (Netherlands)

    Chen, Hsu-Hsin; Welling, Maaike; Bloch, Donald B; Muñoz, Javier; Mientjes, Edwin; Chen, Xinjie; Tramp, Cody; Wu, Jie; Yabuuchi, Akiko; Chou, Yu-Fen; Buecker, Christa; Krainer, Adrian; Willemsen, Rob; Heck, Albert J; Geijsen, Niels

    2014-01-01

    The scarcity of primordial germ cells (PGCs) in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell

  14. SALL4 expression in germ cell and non-germ cell tumors: a systematic immunohistochemical study of 3215 cases.

    Science.gov (United States)

    Miettinen, Markku; Wang, Zengfeng; McCue, Peter A; Sarlomo-Rikala, Maarit; Rys, Janusz; Biernat, Wojciech; Lasota, Jerzy; Lee, Yi-Shan

    2014-03-01

    The SALL4 transcription factor is associated with embryonic cell pluripotency and has been shown as a useful immunohistochemical marker for germ cell tumors. However, information of SALL4 distribution in normal human tissues and non-germ cell tumors is limited. In this study we examined normal human tissues and 3215 tumors for SALL4 expression using a monoclonal antibody 6E3 and automated immunohistochemistry. In a 10-week embryo, SALL4 was expressed in ovocytes, intestine, kidney, and some hepatocytes. In adult tissues, it was only detected in germ cells. SALL4 was consistently expressed in all germ cell tumors except some trophoblastic tumors and mature components of teratomas, in which it was selectively expressed in intestinal-like and some squamous epithelia. In non-germ cell carcinomas, SALL4 was detected in 20% of cases or more of serous carcinoma of the ovary, urothelial high-grade carcinoma, and gastric adenocarcinoma (especially the intestinal type). SALL4 was only rarely (≤ 5%) expressed in mammary, colorectal, prostatic, and squamous cell carcinomas. Many SALL4-positive carcinomas showed poorly differentiated patterns, and some showed positivity in most tumor cells mimicking the expression in germ cell tumors. SALL4 was commonly expressed in rhabdoid tumors of the kidney and extrarenal sites and in the Wilms tumor. Expression of SALL4 was rare in other mesenchymal and neuroendocrine tumors but was occasionally detected in melanoma, desmoplastic small round cell tumor, epithelioid sarcoma, and rhabdomyosarcoma. All hematopoietic tumors were negative. SALL4 is an excellent marker of nonteratomatous germ cell tumors, but it is also expressed in other tumors, sometimes extensively. Such expression may reflect stem cell-like differentiation and must be considered when using SALL4 as a marker for germ cell tumors. Observed lack of other pluripotency factors, OCT4 and NANOG, in SALL4-positive non-germ cell tumors can also be diagnostically helpful.

  15. SALL4 EXPRESSION IN GERM CELL AND NON GERM-CELL TUMORS – A SYSTEMATIC IMMUNOHISTOCHEMICAL STUDY OF 3215 CASES

    Science.gov (United States)

    Miettinen, Markku; Wang, Zengfeng; Mc. Cue, Peter A.; Sarlomo-Rikala, Maarit; Rys, Janusz; Biernat, Wojciech; Lasota, Jerzy; Lee, Yi-Shan

    2014-01-01

    SALL4 transcription factor is associated with embryonic cell pluripotency and has been shown as a useful immunohistochemical marker for germ cell tumors. However, information of SALL4 distribution in normal human tissues and non germ-cell tumors is limited. In this study we examined normal human tissues and 3215 tumors for SALL4 expression using a monoclonal antibody 6E3 and automated immunohistochemistry. In a 10th week embryo, SALL4 was expressed in ovocytes, intestine, kidney, and some hepatocytes. In adult tissues, it was only detected in germ cells. SALL4 was consistently expressed in all germ cell tumors except some trophoblastic tumors and mature components of teratomas, where it was selectively expressed in intestinal-like and some squamous epithelia. In non germ-cell carcinomas, SALL4 was detected in 20% of cases or more of serous carcinoma of ovary, urothelial high-grade carcinoma, and gastric adenocarcinoma (especially the intestinal type). SALL4 was only rarely (≤5%) expressed in mammary, colorectal, prostatic, and squamous cell carcinomas. Many SALL4 positive carcinomas showed poorly differentiated patterns and some showed positivity in most tumor cells mimicking the expression in germ cell tumors. SALL4 was commonly expressed in rhabdoid tumors of kidney and extrarenal sites, and in Wilms tumor. Expression of SALL4 was rare in other mesenchymal and neuroendocrine tumors but was occasionally detected in melanoma, desmoplastic small round cell tumor, epithelioid sarcoma, and rhabdomyosarcoma. All hematopoietic tumors were negative. SALL4 is an excellent marker of non-teratomatous germ cell tumors, but it is also expressed in other tumors, sometimes extensively. Such expression may reflect stem-cell like differentiation and must be considered when using SALL4 as a marker for germ cell tumors. Observed lack of other pluripotency factors, OCT4 and NANOG, in SALL4-positive non-germ cell tumors can also be diagnostically helpful. PMID:24525512

  16. Stopping the Spread of Germs at Home, Work and School

    Science.gov (United States)

    ... Stopping the Spread of Germs at Home, Work & School Language: English (US) Español Recommend on Facebook Tweet ... can help slow the spread of influenza. At School Resources for Schools, Childcare Providers and Parents Information ...

  17. Malignant Ganglioneuroma Arising from Mediastinal Mixed Germ Cell Tumor

    Directory of Open Access Journals (Sweden)

    Pi-Yu Chen

    2007-02-01

    Full Text Available Mixed germ cell tumors with non-germ cell malignant components rarely occur in the anterior mediastinum. We report a case of a 34-year-old man who presented with an anterior mediastinum mass. Mixed germ cell tumor was initially diagnosed based on the pathologic findings of germinoma on thoracoscopic biopsy and clinical findings of elevated serum a-fetoprotein and β-human chorionic gonadotropin. The patient received preoperative chemotherapy and subsequent complete resection of the residual tumor. Pathologic examination of the excised specimen showed predominantly malignant ganglioneuroma and small residual foci of teratoma. To our knowledge, this is the first reported case of a malignant ganglioneuroma arising from mediastinal mixed germ cell tumor.

  18. Coding Partitions

    Directory of Open Access Journals (Sweden)

    Fabio Burderi

    2007-05-01

    Full Text Available Motivated by the study of decipherability conditions for codes weaker than Unique Decipherability (UD, we introduce the notion of coding partition. Such a notion generalizes that of UD code and, for codes that are not UD, allows to recover the ``unique decipherability" at the level of the classes of the partition. By tacking into account the natural order between the partitions, we define the characteristic partition of a code X as the finest coding partition of X. This leads to introduce the canonical decomposition of a code in at most one unambiguouscomponent and other (if any totally ambiguouscomponents. In the case the code is finite, we give an algorithm for computing its canonical partition. This, in particular, allows to decide whether a given partition of a finite code X is a coding partition. This last problem is then approached in the case the code is a rational set. We prove its decidability under the hypothesis that the partition contains a finite number of classes and each class is a rational set. Moreover we conjecture that the canonical partition satisfies such a hypothesis. Finally we consider also some relationships between coding partitions and varieties of codes.

  19. Primary pleuro-pulmonary malignant germ cell tumours.

    Directory of Open Access Journals (Sweden)

    Vaideeswar P

    2002-01-01

    Full Text Available Lungs and pleura are rare sites for malignant germ-cell tumours. Two cases, pure yolk-sac tumour and yolk sac-sac tumour/embryonal carcinoma are described in young males who presented with rapid progression of respiratory symptoms. The malignant mixed germ cell tumour occurred in the right lung, while the yolk-sac tumour had a pseudomesotheliomatous growth pattern suggesting a pleural origin. Alpha-foetoprotein was immunohistochemically demonstrated in both.

  20. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Sammenfatning af de mest væsentlige pointer fra hovedrapporten: Dokumentation og evaluering af Coding Class......Sammenfatning af de mest væsentlige pointer fra hovedrapporten: Dokumentation og evaluering af Coding Class...

  1. Germ Cells are Made Semiotically Competent During Evolution

    DEFF Research Database (Denmark)

    Giorgi, Franco; Bruni, Luis Emilio

    2016-01-01

    Germ cells are cross-roads of development and evolution. They define the origin of every new generation and, at the same time, represent the biological end-product of any mature organism. Germ cells are endowed with the following capacities: (1) to store a self-descriptive program, (2) to accumul......Germ cells are cross-roads of development and evolution. They define the origin of every new generation and, at the same time, represent the biological end-product of any mature organism. Germ cells are endowed with the following capacities: (1) to store a self-descriptive program, (2......) to accumulate a protein-synthesizing machinery (ribosomes), and (3) to incorporate enough nourishment to sustain embryonic development (yolk). To accomplish this goal, germ cells do not simply unfold a pre-determined program or realize a sole instructive role. On the contrary, due to the complexity...... milieu and experience the compatibility of selected developmental sequences. The question of which signaling pathways are activated at each developmental stage does not result from a strictly predetermined program instructing germ cell stemness. Rather, each developmental sequence is an open...

  2. Preconception exposures to potential germ-cell mutagens

    International Nuclear Information System (INIS)

    Draper, G.

    2008-01-01

    Radiation and other agents can cause germ-cell mutations in animal systems. No human germ-cell mutagen has been identified, but this does not mean that human germ-cells are not vulnerable to mutagenesis. There has been particular concern about the possible health effects on offspring following parental preconception exposure to ionizing radiation - both occupational and therapeutic. A strong association with preconception radiation exposure in the fathers of the cases was found in a case-control study of young people with leukaemia living near the Sellafield nuclear plant in the UK. Subsequent studies of workers occupationally exposed to ionizing radiation have failed to confirm these findings. No statistically significant effects have been reported from studies of possible indicators of germ-cell mutagenesis in the A-bomb survivors. Studies of offspring of cancer survivors who receive radiotherapy and mutagenic chemotherapy have found no evidence of germ-cell mutagenesis. Failure to detect human germ-cell mutagenic agents may be a consequence of inadequate study sizes or insufficiently sensitive laboratory techniques. (authors)

  3. Transient translational quiescence in primordial germ cells.

    Science.gov (United States)

    Oulhen, Nathalie; Swartz, S Zachary; Laird, Jessica; Mascaro, Alexandra; Wessel, Gary M

    2017-04-01

    Stem cells in animals often exhibit a slow cell cycle and/or low transcriptional activity referred to as quiescence. Here, we report that the translational activity in the primordial germ cells (PGCs) of the sea urchin embryo ( Strongylocentrotus purpuratus ) is quiescent. We measured new protein synthesis with O-propargyl-puromycin and L-homopropargylglycine Click-iT technologies, and determined that these cells synthesize protein at only 6% the level of their adjacent somatic cells. Knockdown of translation of the RNA-binding protein Nanos2 by morpholino antisense oligonucleotides, or knockout of the Nanos2 gene by CRISPR/Cas9 resulted in a significant, but partial, increase (47%) in general translation specifically in the PGCs. We found that the mRNA of the translation factor eEF1A is excluded from the PGCs in a Nanos2-dependent manner, a consequence of a Nanos/Pumilio response element (PRE) in its 3'UTR. In addition to eEF1A, the cytoplasmic pH of the PGCs appears to repress translation and simply increasing the pH also significantly restores translation selectively in the PGCs. We conclude that the PGCs of this sea urchin institute parallel pathways to quiesce translation thoroughly but transiently. © 2017. Published by The Company of Biologists Ltd.

  4. When the GERM Hosts the Antidote: The Surprising New Birth of Israel's Anti-GERM Pre-K Policy

    Directory of Open Access Journals (Sweden)

    Gadi Bialik

    2017-09-01

    Full Text Available Since the 1970s, Israel's educational policy has been undergoing a change generated by the neo-liberal agenda. In this light, it is not surprising that since the 1990s, Israel’s education system has adopted the main characteristics of the Global Education Reform Movement (GERM. In light of this, the current research will focus on a newly born pre-K policy formation process that set out as GERM-like in nature, but nevertheless ended up with anti-GERM characteristics. Using historical-narrative qualitative tools, this paper will portray and analyze the main factors that generated the new anti-GERMian reform. We will outline conclusions from the Israeli case study to create a potential conceptual framework that highlights a more complex, hybrid, or dual outlook at the GERM containing its antidote within itself.

  5. UV effect on germ cell determinant and a proposed scheme for germ cell formation process in embryos of Xenopus laevis

    International Nuclear Information System (INIS)

    Ijiri, Ken-ichi

    1976-01-01

    Ultraviolet light (UV) irradiation of vegetal hemispheres of many anuran eggs resulted in elimination of primordial germ cells in tadpoles. UV irradiation experiments were performed on the eggs just before the first cleavage division, and a dose-response curve was obtained at that stage. The results supported the probabilistic model for germ cell determination process previously reported by the authors. Cell diameter analysis suggested that germinal plasm-containing cells (i.e. presumptive primordial germ cells) divide at the same rate as ordinary endodermal cells during stages 10-33. This led to calculation of the doubling time of presumptive primordial germ cells, obtaining its value as about 30 hrs at 20 0 C. Finally, a scheme for the proliferation kinetics of germ cells in Xenopus laevis embryos was presented. Several UV experiments on the vegetal hemisphere of anuran eggs have presented favorable evidence that histologically identifiable germinal plasm contains the UV-labile germ cell determinant. Their significance was also discussed. (Evans, J.)

  6. Restricted distribution of mrg-1 mRNA in C. elegans primordial germ cells through germ granule-independent regulation.

    Science.gov (United States)

    Miwa, Takashi; Takasaki, Teruaki; Inoue, Kunio; Sakamoto, Hiroshi

    2015-11-01

    The chromodomain protein MRG-1 is an essential maternal factor for proper germline development that protects germ cells from cell death in C. elegans. Unlike germ granules, which are exclusively segregated to the germline blastomeres at each cell division from the first cleavage of the embryo, MRG-1 is abundant in all cells in early embryos and is then gradually restricted to the primordial germ cells (PGCs) by the morphogenesis stage. Here, we show that this characteristic spatiotemporal expression pattern is dictated by the mrg-1 3'UTR and is differentially regulated at the RNA level between germline and somatic cells. Asymmetric segregation of germ granules is not necessary to localize MRG-1 to the PGCs. We found that MES-4, an essential chromatin regulator in germ cells, also accumulates in the PGCs in a germ granule-independent manner. We propose that C.elegans PGCs have a novel mechanism to accumulate at least some chromatin-associated proteins that are essential for germline immortality. © 2015 The Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  7. DEADSouth protein localizes to germ plasm and is required for the development of primordial germ cells in Xenopus laevis

    Directory of Open Access Journals (Sweden)

    Takeshi Yamaguchi

    2012-11-01

    DEADSouth mRNA is a component of germ plasm in Xenopus laevis and encodes a DDX25 DEAD-box RNA helicase. To determine the intracellular localization of DEADSouth protein, we injected mRNA encoding DEADSouth tagged with mCherry fluorescent protein into fertilized eggs from transgenic Xenopus expressing EGFP fused with a mitochondrial targeting signal. The DEADSouth-mCherry fusion protein was localized to the germ plasm, a mitochondria-rich region in primordial germ cells (PGCs. DEADSouth overexpression resulted in a reduction of PGC numbers after stage 20. Conversely, DEADSouth knockdown using an antisense locked nucleic acid gapmer inhibited movement of the germ plasm from the cortex to the perinuclear region, resulting in inhibition of PGC division at stage 12 and a decrease in PGC numbers at later stages. The knockdown phenotype was rescued by intact DEADSouth mRNA, but not mutant mRNA encoding inactive DEADSouth helicase. Surprisingly, it was also rescued by mouse vasa homolog and Xenopus vasa-like gene 1 mRNAs that encode DDX4 RNA helicases. The rescue was dependent on the 3′ untranslated region (3′UTR of DEADSouth mRNA, which was used for PGC-specific expression. The 3′UTR contributed to localization of the injected mRNA to the germ plasm, resulting in effective localization of DEADSouth protein. These results demonstrate that localization of DEADSouth helicase to the germ plasm is required for proper PGC development in Xenopus laevis.

  8. Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR) as tracers of solar wind conditions near Saturn: Event lists and applications

    Science.gov (United States)

    Roussos, E.; Jackman, C. M.; Thomsen, M. F.; Kurth, W. S.; Badman, S. V.; Paranicas, C.; Kollmann, P.; Krupp, N.; Bučík, R.; Mitchell, D. G.; Krimigis, S. M.; Hamilton, D. C.; Radioti, A.

    2018-01-01

    The lack of an upstream solar wind monitor poses a major challenge to any study that investigates the influence of the solar wind on the configuration and the dynamics of Saturn's magnetosphere. Here we show how Cassini MIMI/LEMMS observations of Solar Energetic Particle (SEP) and Galactic Cosmic Ray (GCR) transients, that are both linked to energetic processes in the heliosphere such us Interplanetary Coronal Mass Ejections (ICMEs) and Corotating Interaction Regions (CIRs), can be used to trace enhanced solar wind conditions at Saturn's distance. SEP protons can be easily distinguished from magnetospheric ions, particularly at the MeV energy range. Many SEPs are also accompanied by strong GCR Forbush Decreases. GCRs are detectable as a low count-rate noise signal in a large number of LEMMS channels. As SEPs and GCRs can easily penetrate into the outer and middle magnetosphere, they can be monitored continuously, even when Cassini is not situated in the solar wind. A survey of the MIMI/LEMMS dataset between 2004 and 2016 resulted in the identification of 46 SEP events. Most events last more than two weeks and have their lowest occurrence rate around the extended solar minimum between 2008 and 2010, suggesting that they are associated to ICMEs rather than CIRs, which are the main source of activity during the declining phase and the minimum of the solar cycle. We also list of 17 time periods ( > 50 days each) where GCRs show a clear solar periodicity ( ∼ 13 or 26 days). The 13-day period that derives from two CIRs per solar rotation dominates over the 26-day period in only one of the 17 cases catalogued. This interval belongs to the second half of 2008 when expansions of Saturn's electron radiation belts were previously reported to show a similar periodicity. That observation not only links the variability of Saturn's electron belts to solar wind processes, but also indicates that the source of the observed periodicity in GCRs may be local. In this case GCR

  9. Specification of primordial germ cells in medaka (Oryzias latipes)

    Science.gov (United States)

    Herpin, Amaury; Rohr, Stefan; Riedel, Dietmar; Kluever, Nils; Raz, Erez; Schartl, Manfred

    2007-01-01

    Background Primordial germ cells (PGCs) give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes). Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of maternally provided

  10. Specification of primordial germ cells in medaka (Oryzias latipes

    Directory of Open Access Journals (Sweden)

    Raz Erez

    2007-01-01

    Full Text Available Abstract Background Primordial germ cells (PGCs give rise to gametes that are responsible for the development of a new organism in the next generation. Two modes of germ line specification have been described: the inheritance of asymmetrically-localized maternally provided cytoplasmic determinants and the induction of the PGC fate by other cell types. PGCs specification in zebrafish appears to depend on inheritance of germ plasm in which several RNA molecules such as vasa and nanos reside. Whether the specification mode of PGCs found in zebrafish is general for other fish species was brought into question upon analysis of olvas expression – the vasa homologue in another teleost, medaka (Oryzias latipes. Here, in contrast to the findings in zebrafish, the PGCs are found in a predictable position relative to a somatic structure, the embryonic shield. This finding, coupled with the fact that vasa mRNA, which is localized to the germ plasm of zebrafish but does not label a similar structure in medaka opened the possibility of fundamentally different mechanisms governing PGC specification in these two fish species. Results In this study we addressed the question concerning the mode of PGC specification in medaka using embryological experiments, analysis of RNA stability in the PGCs and electron microscopy observations. Dramatic alterations in the somatic environment, i.e. induction of a secondary axis or mesoderm formation alteration, did not affect the PGC number. Furthermore, the PGCs of medaka are capable of protecting specific RNA molecules from degradation and could therefore exhibit a specific mRNA expression pattern controlled by posttrancriptional mechanisms. Subsequent analysis of 4-cell stage medaka embryos using electron microscopy revealed germ plasm-like structures located at a region corresponding to that of zebrafish germ plasm. Conclusion Taken together, these results are consistent with the idea that in medaka the inheritance of

  11. On the formation of germ cells: The good, the bad and the ugly.

    Science.gov (United States)

    Chuva de Sousa Lopes, Susana M; Roelen, Bernard A J

    2010-03-01

    Mammalian germ cells are powerful cells, the only ones that transmit information to the next generation ensuring the continuation of the species. But "with great power, comes great responsibility", meaning that germ cells are only a few steps away from turning carcinogenic. Despite recent advances little is known about germ cell formation in mammals, predominantly because of the inaccessibility of these cells. Moreover, it is difficult to pin down what in essence is characteristic of a germ cell, as germ cells keep changing place, morphology, expression markers and epigenetic identity. Formation of (primordial) germ cells in primate ES cell cultures would therefore be helpful to identify molecular signalling pathways associated with germ cell differentiation and to study epigenetic changes in germ cells. In addition, the in vitro derivation of functional germ cells from ES cells could be used in combination with therapeutic cloning to generate patient-specific ES cell lines, and can have applications in animal breeding. In this review we present the state-of-the-art on how mouse and human germ cells are formed in vivo (the good), we discuss the link between germ cells, pluripotency and germ cell tumours (the bad) and show that despite continuous progress in trying to differentiate germ cells in vitro (the ugly) the generation of functional germ cells is still a real challenge. Copyright 2009 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  12. Immunofluorescence Analysis of Testicular Biopsies With Germ Cell and Sertoli Cell Markers Shows Significant MVH Negative Germ Cell Depletion With Older Age of Orchidopexy

    DEFF Research Database (Denmark)

    Li, Ruili; Thorup, Jørgen Mogens; Sun, Cong

    2014-01-01

    Undescended testis is the most common defect in newborn boys. It is associated with increased risks of infertility and testicular malignancy due to abnormal germ cell development in these testes. Early surgery may limit such risks. The aim of our study was to analyse germ cell development verses ...... age of orchidopexy using a germ cell marker and a Sertoli cell marker on testicular biopsies.......Undescended testis is the most common defect in newborn boys. It is associated with increased risks of infertility and testicular malignancy due to abnormal germ cell development in these testes. Early surgery may limit such risks. The aim of our study was to analyse germ cell development verses...

  13. Conversion of primordial germ cells to pluripotent stem cells: methods for cell tracking and culture conditions.

    Science.gov (United States)

    Nagamatsu, Go; Suda, Toshio

    2013-01-01

    Primordial germ cells (PGCs) are unipotent cells committed to germ lineage: PGCs can only differentiate into gametes in vivo. However, upon fertilization, germ cells acquire the capacity to differentiate into all cell types in the body, including germ cells. Therefore, germ cells are thought to have the potential for pluripotency. PGCs can convert to pluripotent stem cells in vitro when cultured under specific conditions that include bFGF, LIF, and the membrane-bound form of SCF (mSCF). Here, the culture conditions which efficiently convert PGCs to pluripotent embryonic germ (EG) cells are described, as well as methods used for identifying pluripotent candidate cells during culture.

  14. ATTEMPT TO APPLY STABILIZED WHEAT GERM FOR BREAD SUPPLEMENTATION

    Directory of Open Access Journals (Sweden)

    Halina Gambuś

    2015-02-01

    Full Text Available The increased interest in rational nutrition causes, that from many years is observed a growing consumption of bread, and novel food supplemented with health promoting components. For the bread production in Poland mainly wheat and rye cake flours are used, depleted of a many valuable nutrients such as protein, dietary fibre, minerals and vitamins. Because of their unique chemical composition wheat germs are a particularly valuable resource, both for direct consumption and to enhance the nutritional value of food products. The aim of the study was to prepare wheat bread with a 10% addition of commercial stabilized wheat germs. Based on the obtained results, it was found that wheat germs, due to their unique chemical composition, were a particularly valuable resource to supplement the nutritional value of bread. However, germs had detrimental effect on mechanical properties of dough, and on bread quality. Texture of bread crumb and its chemical composition were analysed. It was shown, that germs subjected to fermentation process could be used in wheat bread production as dietary fibre and mineral compound supplement.

  15. Nuclear Reprogramming in Mouse Primordial Germ Cells: Epigenetic Contribution

    Directory of Open Access Journals (Sweden)

    Massimo De Felici

    2011-01-01

    Full Text Available The unique capability of germ cells to give rise to a new organism, allowing the transmission of primary genetic information from generation to generation, depends on their epigenetic reprogramming ability and underlying genomic totipotency. Recent studies have shown that genome-wide epigenetic modifications, referred to as “epigenetic reprogramming”, occur during the development of the gamete precursors termed primordial germ cells (PGCs in the embryo. This reprogramming is likely to be critical for the germ line development itself and necessary to erase the parental imprinting and setting the base for totipotency intrinsic to this cell lineage. The status of genome acquired during reprogramming and the associated expression of key pluripotency genes render PGCs susceptible to transform into pluripotent stem cells. This may occur in vivo under still undefined condition, and it is likely at the origin of the formation of germ cell tumors. The phenomenon appears to be reproduced under partly defined in vitro culture conditions, when PGCs are transformed into embryonic germ (EG cells. In the present paper, I will try to summarize the contribution that epigenetic modifications give to nuclear reprogramming in mouse PGCs.

  16. Network Coding

    Indian Academy of Sciences (India)

    message symbols downstream, network coding achieves vast performance gains by permitting intermediate nodes to carry out algebraic oper- ations on the incoming data. In this article we present a tutorial introduction to network coding as well as an application to the e±cient operation of distributed data-storage networks.

  17. [Metastasis of germ cell tumors of the testis].

    Science.gov (United States)

    Machover, D; Goldschmidt, E

    1991-01-01

    The development of metastases from germ cell tumours of the testis is studied in terms of its histopathological, ontogenetic, anatomical and evolutive aspects. The treatment of non-seminomatous germ cell tumours and pure seminomas is analysed separately. The prognostic factors defined by the risk of failure of treatment are described and the medical and surgical strategies or combinations of both modalities are proposed for each stage of these cancers. The major points and novelties include: the usual histological polymorphism of these tumours. The markers include alpha-foetoprotein and HCG. Combination chemotherapy, essentially the EBP sequence, is the treatment for non-seminomatous germ cell tumours. In the case of failure, toxic sequences can be used followed by autologous bone marrow transplantation. In the case of persistent lesions (lung, mediastinum, liver, retroperitoneum), salvage surgery may be useful. Metastatic seminomas are treated by radiotherapy and/or chemotherapy, depending on their stage.

  18. "Mixed germ cell testicular tumor" in an adult female

    Directory of Open Access Journals (Sweden)

    Udasimath Shivakumarswamy

    2012-01-01

    Full Text Available The androgen insensitivity (testicular feminization syndrome was described by Morris in phenotypic females with 46XY karyotype, presenting with primary amenorrhea, adequate breast development, and absent or scanty pubic or axillary hair. Gonads consist usually of seminiferous tubules without spermatogenesis. These patients have a 5-10% risk of developing germ cell tumors, usually after the complete development of secondary female sexual characteristics. We hereby report a case considered as a female with married life of 15 years, who was operated for severe abdominal pain. Phenotype characters were that of female. Microscopic examination of the tumor from the abdomen revealed germinoma and yolk sac tumor with adjacent seminiferous tubules. Karyotyping showed 46XY. Final diagnosis of malignant mixed germ cell tumor in androgen insensitivity syndrome was made. Surveillance may be the most appropriate option when these conditions are initially diagnosed in adulthood to prevent development of germ cell tumors.

  19. Single-Cell Expression Profiling and Proteomics of Primordial Germ Cells, Spermatogonial Stem Cells, Adult Germ Stem Cells, and Oocytes.

    Science.gov (United States)

    Conrad, Sabine; Azizi, Hossein; Skutella, Thomas

    2018-01-04

    The mammalian germ cells, cell assemblies, tissues, and organs during development and maturation have been extensively studied at the tissue level. However, to investigate and understand the fundamental insights at the molecular basis of germ and stem cells, their cell fate plasticity, and determination, it is of most importance to analyze at the large scale on the single-cell level through different biological windows. Here, modern molecular techniques optimized for single-cell analysis, including single fluorescence-activated cell sorting (FACS) and single-cell RNA sequencing (scRNA-seq) or microfluidic high-throughput quantitative real-time polymerase chain reaction (qRT-PCR) for single-cell gene expression and liquid chromatography coupled to tandem mass spectrometry (LC-MSMS) for protein profiling, have been established and are still getting optimized.This review aims on describing and discussing recent single-cell expression profiling and proteomics of different types of human germ cells, including primordial germ cells (PGCs), spermatogonial stem cells (SSCs), human adult germ stem cells (haGSCs), and oocytes.

  20. Male germ cells express abundant endogenous siRNAs

    Science.gov (United States)

    Song, Rui; Hennig, Grant W.; Wu, Qiuxia; Jose, Charlie; Zheng, Huili; Yan, Wei

    2011-01-01

    In mammals, endogenous siRNAs (endo-siRNAs) have only been reported in murine oocytes and embryonic stem cells. Here, we show that murine spermatogenic cells express numerous endo-siRNAs, which are likely to be derived from naturally occurring double-stranded RNA (dsRNA) precursors. The biogenesis of these testicular endo-siRNAs is DROSHA independent, but DICER dependent. These male germ cell endo-siRNAs can potentially target hundreds of transcripts or thousands of DNA regions in the genome. Overall, our work has unveiled another hidden layer of regulation imposed by small noncoding RNAs during male germ cell development. PMID:21788498

  1. A functional genomic screen in planarians identifies novel regulators of germ cell development.

    Science.gov (United States)

    Wang, Yuying; Stary, Joel M; Wilhelm, James E; Newmark, Phillip A

    2010-09-15

    Germ cells serve as intriguing examples of differentiated cells that retain the capacity to generate all cell types of an organism. Here we used functional genomic approaches in planarians to identify genes required for proper germ cell development. We conducted microarray analyses and in situ hybridization to discover and validate germ cell-enriched transcripts, and then used RNAi to screen for genes required for discrete stages of germ cell development. The majority of genes we identified encode conserved RNA-binding proteins, several of which have not been implicated previously in germ cell development. We also show that a germ cell-specific subunit of the conserved transcription factor CCAAT-binding protein/nuclear factor-Y is required for maintaining spermatogonial stem cells. Our results demonstrate that conserved transcriptional and post-transcriptional mechanisms regulate germ cell development in planarians. These findings suggest that studies of planarians will inform our understanding of germ cell biology in higher organisms.

  2. [Human Primordial Germ Cell Specification--Breakthrough In Culture and Hopes for Therapeutic Utilization].

    Science.gov (United States)

    Magnúsdóttir, Erna

    2015-10-01

    Germ cells are the precursors to the gametes that carry genetic and epigenetic information between human generations and generate a new individual. Because germ cells are specified early during embryogenesis, at the time of embryo implantation, they are inaccessible for research. Our understanding of their biology has therefore developed slowly since their identification over one hundred years ago. As a result of research into the properties of human and mouse embryonic stem cells and primordial germ cells, scientists have now succeeded in efficiently generating human primordial germ cells in culture by embryonic stem cell and induced pluripotent stem cell culture. In this review we will discuss the state of our knowledge of human primordial germ cells and how research into the pluripotent properties of human and mouse embryonic germ cells has led to this breakthrough. In addition we will discuss the possible utilization of a cell culture system of human primordial germ cells for research into and treatment of germ cell related abnormalities.

  3. MASTL is essential for anaphase entry of proliferating primordial germ cells and establishment of female germ cells in mice

    OpenAIRE

    Risal, Sanjiv; Zhang, Jingjing; Adhikari, Deepak; Liu, Xiaoman; Shao, Jingchen; Hu, Mengwen; Busayavalasa, Kiran; Tu, Zhaowei; Chen, Zijiang; Kaldis, Philipp; Liu, Kui

    2017-01-01

    In mammals, primordial germ cells (PGCs) are the embryonic cell population that serve as germ cell precursors in both females and males. During mouse embryonic development, the majority of PGCs are arrested at the G2 phase when they migrate into the hindgut at 7.75?8.75?dpc (days post coitum). It is after 9.5?dpc that the PGCs undergo proliferation with a doubling time of 12.6?h. The molecular mechanisms underlying PGC proliferation are however not well studied. In this work. Here we studied ...

  4. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect

    Directory of Open Access Journals (Sweden)

    Ben Ewen-Campen

    2013-04-01

    Primordial germ cell (PGC formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this “germ plasm” acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects.

  5. Evidence against a germ plasm in the milkweed bug Oncopeltus fasciatus, a hemimetabolous insect.

    Science.gov (United States)

    Ewen-Campen, Ben; Jones, Tamsin E M; Extavour, Cassandra G

    2013-06-15

    Primordial germ cell (PGC) formation in holometabolous insects like Drosophila melanogaster relies on maternally synthesised germ cell determinants that are asymmetrically localised to the oocyte posterior cortex. Embryonic nuclei that inherit this "germ plasm" acquire PGC fate. In contrast, historical studies of basally branching insects (Hemimetabola) suggest that a maternal requirement for germ line genes in PGC specification may be a derived character confined principally to Holometabola. However, there have been remarkably few investigations of germ line gene expression and function in hemimetabolous insects. Here we characterise PGC formation in the milkweed bug Oncopeltus fasciatus, a member of the sister group to Holometabola, thus providing an important evolutionary comparison to members of this clade. We examine the transcript distribution of orthologues of 19 Drosophila germ cell and/or germ plasm marker genes, and show that none of them localise asymmetrically within Oncopeltus oocytes or early embryos. Using multiple molecular and cytological criteria, we provide evidence that PGCs form after cellularisation at the site of gastrulation. Functional studies of vasa and tudor reveal that these genes are not required for germ cell formation, but that vasa is required in adult males for spermatogenesis. Taken together, our results provide evidence that Oncopeltus germ cells may form in the absence of germ plasm, consistent with the hypothesis that germ plasm is a derived strategy of germ cell specification in insects.

  6. DAZL limits pluripotency, differentiation, and apoptosis in developing primordial germ cells

    NARCIS (Netherlands)

    H.H. Chen; M. Welling (Maaike); D.B. Bloch (Donald B.); J. Muñoz (Javier); E.J. Mientjes (Edwin); X. Chen (Xinjie); C. Tramp (Cody); J. Wu (Jie); A. Yabuuchi (Akiko); Y.F. Chou; C. Buecker (Christa); A. Krainer (Adrian); R. Willemsen (Rob); A.J.R. Heck (Albert); N. Geijsen (Niels)

    2014-01-01

    textabstractThe scarcity of primordial germ cells (PGCs) in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro

  7. Sex steroid production associated with puberty is absent in germ cell-free salmon

    NARCIS (Netherlands)

    Kleppe, Lene; Andersson, Eva; Skaftnesmo, Kai Ove; Edvardsen, Rolf B; Fjelldal, Per Gunnar; Norberg, Birgitta; Bogerd, Jan; Schulz, Rüdiger W; Wargelius, Anna

    2017-01-01

    In all vertebrates studied so far, germ cells are not required for pubertal maturation of the gonadal steroidogenic system, subsequent development of secondary sex characteristics and reproductive behavior. To explore if the absence of germ cells affects puberty or growth in Atlantic salmon, germ

  8. Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)—Patient Version

    Science.gov (United States)

    Childhood central nervous system (CNS) germ cell tumors form from germ cells (a type of cell that forms as a fetus develops and later becomes sperm in the testicles or eggs in the ovaries). Learn about the signs, tests to diagnose, and treatment of pediatric germ cell tumors in the brain in this expert-reviewed summary.

  9. Improved solubility and emulsification of wet-milled corn germ protein recovered by ultrafiltration-diafiltration

    Science.gov (United States)

    This study evaluated ultrafiltration-diafiltration (UFDF) as a means to improve the extractability of wet-milled corn germ protein and determined its effects on the functional properties of the recovered protein product. Wet germ (WG) and finished germ (FG) proteins (Pr) were extracted by using 0.1M...

  10. Adult Immunohistochemical Markers Fail to Detect Intratubular Germ Cell Neoplasia in Prepubertal Boys with Cryptorchidism

    DEFF Research Database (Denmark)

    Kvist, Kolja; Clasen-Linde, Erik; Cortes, Dina

    2013-01-01

    Intratubular germ cell neoplasia (ITGCN) is a precursor to testicular germ cell cancer. It is characterized by large germ cells with large nuclei with a hyperchromatic, coarse chromatin pattern, large prominent nucleoli and abundant pale cytoplasm. In prepubertal boys these cells are located both...

  11. Coding Class

    DEFF Research Database (Denmark)

    Ejsing-Duun, Stine; Hansbøl, Mikala

    Denne rapport rummer evaluering og dokumentation af Coding Class projektet1. Coding Class projektet blev igangsat i skoleåret 2016/2017 af IT-Branchen i samarbejde med en række medlemsvirksomheder, Københavns kommune, Vejle Kommune, Styrelsen for IT- og Læring (STIL) og den frivillige forening......, design tænkning og design-pædagogik, Stine Ejsing-Duun fra Forskningslab: It og Læringsdesign (ILD-LAB) ved Institut for kommunikation og psykologi, Aalborg Universitet i København. Vi har fulgt og gennemført evaluering og dokumentation af Coding Class projektet i perioden november 2016 til maj 2017....... Coding Class projektet er et pilotprojekt, hvor en række skoler i København og Vejle kommuner har igangsat undervisningsaktiviteter med fokus på kodning og programmering i skolen. Evalueringen og dokumentationen af projektet omfatter kvalitative nedslag i udvalgte undervisningsinterventioner i efteråret...

  12. Coding Labour

    Directory of Open Access Journals (Sweden)

    Anthony McCosker

    2014-03-01

    Full Text Available As well as introducing the Coding Labour section, the authors explore the diffusion of code across the material contexts of everyday life, through the objects and tools of mediation, the systems and practices of cultural production and organisational management, and in the material conditions of labour. Taking code beyond computation and software, their specific focus is on the increasingly familiar connections between code and labour with a focus on the codification and modulation of affect through technologies and practices of management within the contemporary work organisation. In the grey literature of spreadsheets, minutes, workload models, email and the like they identify a violence of forms through which workplace affect, in its constant flux of crisis and ‘prodromal’ modes, is regulated and governed.

  13. 10 original article dynamics of germs responsible for acute bacterial ...

    African Journals Online (AJOL)

    boaz

    The aim of this study was to analyze ten (10) years of epidemiological surveillance data of meningitis in Burkina Faso for high risk germs patterns identification in order to contribute to the strengthening of prevention strategies. A retrospective study of the past decade (2005- 2014) of cases of acute bacterial meningitis ...

  14. Dynamics of germs responsible for acute bacterial meningitis in ...

    African Journals Online (AJOL)

    The aim of this study was to analyze ten (10) years of epidemiological surveillance data of meningitis in Burkina Faso for high risk germs patterns identification in order to contribute to the strengthening of prevention strategies. A retrospective study of the past decade (2005- 2014) of cases of acute bacterial meningitis ...

  15. Clinical and genetic aspects of testicular germ cell tumours

    NARCIS (Netherlands)

    Holzik, Martijn F. Lutke; Sijmons, Rolf H.; Hoekstra-Weebers, Josette E. H. M.; Sleijfer, Dirk Th.; Hoekstra, Harald J.

    2008-01-01

    In this paper we review clinical and genetic aspects of testicular germ cell tumours (TGCTs). TGCT is the most common type of malignant disorder in men aged 15-40 years. Its incidence has increased sharply in recent years. Fortunately, survival of patients with TGCT has improved enormously, which

  16. Towards Optimal Diagnosis of Type II Germ Cell Tumors

    NARCIS (Netherlands)

    J.A. Stoop (Hans)

    2011-01-01

    textabstractThe aim of the work described in this thesis is to improve the understanding of the pathobiology of testicular cancer (type II Germ Cell Tumors) to create possibilities for optimalization of diagnosis for this type of malignancy in routine pathology laboratories. The different studies

  17. Sacrococcygeal germ-cell tumours - the Red Cross War Memorial ...

    African Journals Online (AJOL)

    Patients. Twenty-seven patients with sacrococcygeal germ-cell tumours were treated in our hospital from 1980 to 1996. Design. A retrospective review of these patients' records was undertaken. Results. There were 19 female and 8 male patients. Seventeen (63%) presented in the neonatal period, 13 on the first day of life.

  18. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    심정은

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-. CO2) at a semi-batch flow ... With better refining technologies, these resources can be turned into value added products. ..... parameter determination of vegetable oil oxidation under rancimat test conditions (Reza et al., ...

  19. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    Wheat germ oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SCCO2) at a semi-batch flow extraction process. The supercritical carbon dioxide (SC-CO2) extraction was carried out to extract oil at temperature of 40°C and pressure of 25 MPa. Ethanolysis was performed with 1 ...

  20. Wheat Germ Oil Attenuates Gamma Radiation-Induced Skeletal ...

    African Journals Online (AJOL)

    Muscular strength is important in sport as well as in daily activities. Exposure to ionizing radiation is thought to increase oxidative stress and damage muscle tissue. Wheat germ oil is a natural unrefined vegetable oil. It is an excellent source of vitamin E, octacosanol, linoleic and linolenic essential fatty acids, which may be ...

  1. Reprogramming primordial germ cells into pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Gabriela Durcova-Hills

    Full Text Available Specification of primordial germ cells (PGCs results in the conversion of pluripotent epiblast cells into monopotent germ cell lineage. Blimp1/Prmt5 complex plays a critical role in the specification and maintenance of the early germ cell lineage. However, PGCs can be induced to dedifferentiate back to a pluripotent state as embryonic germ (EG cells when exposed to exogenous signaling molecules, FGF-2, LIF and SCF.Here we show that Trichostatin A (TSA, an inhibitor of histone deacetylases, is a highly potent agent that can replace FGF-2 to induce dedifferentiation of PGCs into EG cells. A key early event during dedifferentiation of PGCs in response to FGF-2 or TSA is the down-regulation of Blimp1, which reverses and apparently relieves the cell fate restriction imposed by it. Notably, the targets of Blimp1, which include c-Myc and Klf-4, which represent two of the key factors known to promote reprogramming of somatic cells to pluripotent state, are up-regulated. We also found early activation of the LIF/Stat-3 signaling pathway with the translocation of Stat-3 into the nucleus. By contrast, while Prmt5 is retained in EG cells, it translocates from the nucleus to the cytoplasm where it probably has an independent role in regulating pluripotency.We propose that dedifferentiation of PGCs into EG cells may provide significant mechanistic insights on early events associated with reprogramming of committed cells to a pluripotent state.

  2. Cholesterol induces proliferation of chicken primordial germ cells.

    Science.gov (United States)

    Chen, Dongyang; Chen, Meijuan; Lu, Zhenping; Yang, Mengmeng; Xie, Long; Zhang, Wenxin; Xu, Huiyan; Lu, Kehuan; Lu, Yangqing

    2016-08-01

    Primordial germ cells (PGCs) are the precursors of sperm and eggs and may serve as suitable cells for use in research in developmental biology and transgenic animals. However, the long-term propagation of PGCs in vitro has so far been plagued by the loss of their germ cell characteristics. This is largely because of the scarcity of knowledge concerning cell division and proliferation in these cells and the poor optimization of the culture medium. The sonic hedgehog (SHH) signaling pathway is involved in proliferation of many types of cells, but little is known about its role in chicken PGCs. The results of the current study indicate that the proliferation of chicken PGCs increases significantly when cholesterol, a molecule that facilitates the trafficking of HH ligands, is supplemented in the culture medium. This effect was attenuated when an SHH antagonist, cyclopamine was added, suggesting the involvement of SHH signaling in this process. The characterization of PGCs treated with cholesterol has shown that these cells express germ-cell-related markers and retain their capability to colonize the embryonic gonad after re-introduction to vasculature of stage-15 HH embryos, indicating that proliferation of PGCs induced by cholesterol does not alter the germ cell characteristics of these cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Primordial Germ Cell Isolation from Xenopus laevis Embryos.

    Science.gov (United States)

    Butler, Amanda M; Aguero, Tristan; Newman, Karen M; King, Mary Lou

    2017-01-01

    Primordial germ cells (PGCs) are the precursors to the gametes and have the unique ability to retain full developmental potential. However, the mechanism(s) and gene-network(s) necessary for their proper specification and development are poorly understood. This is due, in part, to the challenges that must be overcome in order to identify and isolate PGCs during critical stages of development. Two distinct mechanisms have been characterized to specify the germ cell lineage in vertebrates: induction and inheritance. Regardless of mechanism, there are common developmental features shared among all vertebrates in forming the germ cell lineage. Xenopus offers several advantages for understanding the molecular mechanisms necessary to establish the germ line. Here, we provide detailed methods for isolating live PGCs at different time points: 1) just after they have segregated from the endodermal lineage, and 2) while they are migrating towards the presumptive gonad. Isolation of PGCs at these critical developmental stages will allow for the investigation of the mechanism(s) and gene-network(s) necessary for their proper specification and development.

  4. Induction of Primordial Germ Cells from Pluripotent Epiblast

    Directory of Open Access Journals (Sweden)

    Ying Ying

    2002-01-01

    Full Text Available The formation of germ cells during embryogenesis bears the ultimate importance for the continuation of every species. It becomes evident that mechanisms governing germ cell fate specification are not well conserved across the animal kingdom. In most of the invertebrate and nonmammalian vertebrate species, certain maternally derived factors are key to the establishment of germ cell lineage. In contrast, mouse primordial germ cells (PGCs are induced from the pluripotent epiblast cells before and during gastrulation by the extraembryonic cell-derived signals. The molecular identity for some of these signals has recently been revealed by genetic and epiblast culture experiments. Both bone morphogenetic proteins 4 (Bmp4 and 8b (Bmp8b are expressed in the extraembryonic ectoderm and are required for PGC formation. Furthermore, BMP4 or BMP8B alone are unable to induce PGCs from cultured epiblasts, while they can in combination, indicating they signal through separate receptor complexes. In addition, Bmp4 homozygous embryos cannot be induced to form PGCs by the synergistic action of BMP4 and BMP8B, suggesting that BMP4 proteins produced by pregastrula embryos are required for epiblast cells to maintain pluripotency. Moreover, Bmp2, a close relative of Bmp4, is expressed in visceral endoderm at the time of PGC specification, and inactivation of Bmp2 results in a reduction in PGC number, revealing a novel function of visceral endoderm in PGC generation in the mouse.

  5. Genetic analysis of neonatal and infantile germ cell tumours.

    NARCIS (Netherlands)

    Veltman, I.M.

    2006-01-01

    Human germ cell tumours (GCTs) can be classified into five distinct types, based on differences in anatomical location, histology, clinical outcome, age and genotype. The first type, the type I GCTs primarily occur in neonates and infants under the age of five years and include teratomas and yolk

  6. Germ cell tumours in neonates and infants: a distinct subgroup?

    NARCIS (Netherlands)

    Veltman, I.M.; Schepens, M.T.M.; Looijenga, L.H.J.; Strong, L.C.; Geurts van Kessel, A.H.M.

    2003-01-01

    Human germ cell tumours (GCTs) constitute a heterogeneous group of tumours that can be classified into four major subgroups. One of these subgroups encompasses (immature) teratomas and yolk sac tumours of patients under the age of 5 years. In this paper we review the various clinical, histological

  7. Molecular determinants of treatment response in human germ cell tumors

    NARCIS (Netherlands)

    F. Mayer; J.A. Stoop (Hans); G.L. Scheffer (George); R. Scheper; J.W. Oosterhuis (Wolter); L.H.J. Looijenga (Leendert); C. Bokemeyer

    2003-01-01

    textabstractPURPOSE: Germ cell tumors (GCTs) are highly sensitive to cisplatin-based chemotherapy. This feature is unexplained, as is the intrinsic chemotherapy resistance of mature teratomas and the resistant phenotype of a minority of refractory GCTs. Various cellular pathways

  8. Retrotransposons and germ cells: reproduction, death, and diversity.

    Science.gov (United States)

    Seisenberger, Stefanie; Popp, Christian; Reik, Wolf

    2010-06-16

    The evolutionary success of retrotransposable elements is reflected by their abundance in mammalian genomes. To restrict their further advance, a number of defence mechanisms have been put in place by the host. These seem to be particularly effective in the germ line while somatic lineages might be more permissive to new insertions, as recent work by Kano and colleagues suggests.

  9. Forget the Parents: Epigenetic Reprogramming in Human Germ Cells.

    Science.gov (United States)

    von Meyenn, Ferdinand; Reik, Wolf

    2015-06-04

    Epigenetic reprogramming in the germline resets genomic potential and erases epigenetic memory. Three studies by Gkountela et al., Guo et al., and Tang et al. analyze the transcriptional and epigenetic landscape of human primordial germ cells, revealing a unique transcriptional network and progressive and conserved global erasure of DNA methylation. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Radiosensitivity of germs, grafts and vegetating potato plants

    International Nuclear Information System (INIS)

    Kutovenko, L.N.; Serebrenikov, V.S.

    1977-01-01

    Sensitivity of germs, grafts and vegetating potato plants to γ-radiation with doses of 1, 2, 3 and 5 kR has been investigated. While radiation dose increases the percentage of the survived buds and grafts decreases. Radiosensitivity of potato plants is affected not only by a radiation dose but also by the physiological state of the plant

  11. Molecular mechanisms governing primordial germ cell migration in zebrafish

    NARCIS (Netherlands)

    Doitsidou, M.

    2005-01-01

    In most sexually reproducing organisms primordial germ cells (pGCs) are specified early in development in places that are distinct from the region where the somatic part of the gonad develops. From their places of specification they have to migrate towards the site where they associate with somatic

  12. Stability of wheat germ oil obtained by supercritical carbon dioxide ...

    African Journals Online (AJOL)

    심정은

    For determination of stability, wheat germ oil obtained by ethanolysis reactants was characterized by ... extract non polar lipids with lipid soluble bioactive com- pounds from different sources (Esquivel et al., 1997; ... thin layer of cotton was placed at the bottom of the extraction vessel. Before plugging with cap another layer of ...

  13. Genetic predisposition to testicular germ-cell tumours

    NARCIS (Netherlands)

    Lutke-Holzik, MF; Rapley, EA; Hoekstra, HJ; Sleijfer, DT; Nolte, IM; Sijmons, RH

    Testicular germ-cell tumours (TGCT) are the most common neoplasm in young men. Various studies have suggested the existence of an inherited predisposition to development of these tumours. Genome-wide screens subsequently provided evidence of a TGCT susceptibility gene on chromosome Xq27 (TGCT1) that

  14. Characterisation and germline transmission of cultured avian primordial germ cells.

    Science.gov (United States)

    Macdonald, Joni; Glover, James D; Taylor, Lorna; Sang, Helen M; McGrew, Michael J

    2010-11-29

    Avian primordial germ cells (PGCs) have significant potential to be used as a cell-based system for the study and preservation of avian germplasm, and the genetic modification of the avian genome. It was previously reported that PGCs from chicken embryos can be propagated in culture and contribute to the germ cell lineage of host birds. We confirm these results by demonstrating that PGCs from a different layer breed of chickens can be propagated for extended periods in vitro. We demonstrate that intracellular signalling through PI3K and MEK is necessary for PGC growth. We carried out an initial characterisation of these cells. We find that cultured PGCs contain large lipid vacuoles, are glycogen rich, and express the stem cell marker, SSEA-1. These cells also express the germ cell-specific proteins CVH and CDH. Unexpectedly, using RT-PCR we show that cultured PGCs express the pluripotency genes c-Myc, cKlf4, cPouV, cSox2, and cNanog. Finally, we demonstrate that the cultured PGCs will migrate to and colonise the forming gonad of host embryos. Male PGCs will colonise the female gonad and enter meiosis, but are lost from the gonad during sexual development. In male hosts, cultured PGCs form functional gametes as demonstrated by the generation of viable offspring. The establishment of in vitro cultures of germline competent avian PGCs offers a unique system for the study of early germ cell differentiation and also a comparative system for mammalian germ cell development. Primary PGC lines will form the basis of an alternative technique for the preservation of avian germplasm and will be a valuable tool for transgenic technology, with both research and industrial applications.

  15. Characterisation and germline transmission of cultured avian primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Joni Macdonald

    Full Text Available BACKGROUND: Avian primordial germ cells (PGCs have significant potential to be used as a cell-based system for the study and preservation of avian germplasm, and the genetic modification of the avian genome. It was previously reported that PGCs from chicken embryos can be propagated in culture and contribute to the germ cell lineage of host birds. PRINCIPAL FINDINGS: We confirm these results by demonstrating that PGCs from a different layer breed of chickens can be propagated for extended periods in vitro. We demonstrate that intracellular signalling through PI3K and MEK is necessary for PGC growth. We carried out an initial characterisation of these cells. We find that cultured PGCs contain large lipid vacuoles, are glycogen rich, and express the stem cell marker, SSEA-1. These cells also express the germ cell-specific proteins CVH and CDH. Unexpectedly, using RT-PCR we show that cultured PGCs express the pluripotency genes c-Myc, cKlf4, cPouV, cSox2, and cNanog. Finally, we demonstrate that the cultured PGCs will migrate to and colonise the forming gonad of host embryos. Male PGCs will colonise the female gonad and enter meiosis, but are lost from the gonad during sexual development. In male hosts, cultured PGCs form functional gametes as demonstrated by the generation of viable offspring. CONCLUSIONS: The establishment of in vitro cultures of germline competent avian PGCs offers a unique system for the study of early germ cell differentiation and also a comparative system for mammalian germ cell development. Primary PGC lines will form the basis of an alternative technique for the preservation of avian germplasm and will be a valuable tool for transgenic technology, with both research and industrial applications.

  16. Speech coding

    Energy Technology Data Exchange (ETDEWEB)

    Ravishankar, C., Hughes Network Systems, Germantown, MD

    1998-05-08

    Speech is the predominant means of communication between human beings and since the invention of the telephone by Alexander Graham Bell in 1876, speech services have remained to be the core service in almost all telecommunication systems. Original analog methods of telephony had the disadvantage of speech signal getting corrupted by noise, cross-talk and distortion Long haul transmissions which use repeaters to compensate for the loss in signal strength on transmission links also increase the associated noise and distortion. On the other hand digital transmission is relatively immune to noise, cross-talk and distortion primarily because of the capability to faithfully regenerate digital signal at each repeater purely based on a binary decision. Hence end-to-end performance of the digital link essentially becomes independent of the length and operating frequency bands of the link Hence from a transmission point of view digital transmission has been the preferred approach due to its higher immunity to noise. The need to carry digital speech became extremely important from a service provision point of view as well. Modem requirements have introduced the need for robust, flexible and secure services that can carry a multitude of signal types (such as voice, data and video) without a fundamental change in infrastructure. Such a requirement could not have been easily met without the advent of digital transmission systems, thereby requiring speech to be coded digitally. The term Speech Coding is often referred to techniques that represent or code speech signals either directly as a waveform or as a set of parameters by analyzing the speech signal. In either case, the codes are transmitted to the distant end where speech is reconstructed or synthesized using the received set of codes. A more generic term that is applicable to these techniques that is often interchangeably used with speech coding is the term voice coding. This term is more generic in the sense that the

  17. Selective accumulation of germ-line associated gene products in early development of the sea star and distinct differences from germ-line development in the sea urchin.

    Science.gov (United States)

    Fresques, Tara; Zazueta-Novoa, Vanesa; Reich, Adrian; Wessel, Gary M

    2014-04-01

    Echinodermata is a diverse phylum, a sister group to chordates, and contains diverse organisms that may be useful to understand varied mechanisms of germ-line specification. We tested 23 genes in development of the sea star Patiria miniata that fall into five categories: (1) Conserved germ-line factors; (2) Genes involved in the inductive mechanism of germ-line specification; (3) Germ-line associated genes; (4) Molecules involved in left-right asymmetry; and (5) Genes involved in regulation and maintenance of the genome during early embryogenesis. Overall, our results support the contention that the posterior enterocoel is a source of the germ line in the sea star P. miniata. The germ line in this organism appears to be specified late in embryogenesis, and in a pattern more consistent with inductive interactions amongst cells. This is distinct from the mechanism seen in sea urchins, a close relative of the sea star clad. We propose that P. miniata may serve as a valuable model to study inductive mechanisms of germ-cell specification and when compared with germ-line formation in the sea urchin S. purpuratus may reveal developmental transitions that occur in the evolution of inherited and inductive mechanisms of germ-line specification. Copyright © 2013 Wiley Periodicals, Inc.

  18. NSURE code

    International Nuclear Information System (INIS)

    Rattan, D.S.

    1993-11-01

    NSURE stands for Near-Surface Repository code. NSURE is a performance assessment code. developed for the safety assessment of near-surface disposal facilities for low-level radioactive waste (LLRW). Part one of this report documents the NSURE model, governing equations and formulation of the mathematical models, and their implementation under the SYVAC3 executive. The NSURE model simulates the release of nuclides from an engineered vault, their subsequent transport via the groundwater and surface water pathways tot he biosphere, and predicts the resulting dose rate to a critical individual. Part two of this report consists of a User's manual, describing simulation procedures, input data preparation, output and example test cases

  19. Speaking Code

    DEFF Research Database (Denmark)

    Cox, Geoff

    Speaking Code begins by invoking the “Hello World” convention used by programmers when learning a new language, helping to establish the interplay of text and code that runs through the book. Interweaving the voice of critical writing from the humanities with the tradition of computing and softwa...... expression in the public realm. The book’s line of argument defends language against its invasion by economics, arguing that speech continues to underscore the human condition, however paradoxical this may seem in an era of pervasive computing....

  20. A study on effective extraction of isoflavones from soy germ using the electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Hoon [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongup-si, 580-185 Jeollabuk-do (Korea, Republic of); Choi, Tae Beom [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongup-si, 580-185 Jeollabuk-do (Korea, Republic of); Department of Chemistry, Dongguk University, 3 Pildong, Chunggu, Seoul 100-715 (Korea, Republic of); Kim, Sang Wook [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongup-si, 580-185 Jeollabuk-do (Korea, Republic of)], E-mail: swkim@kaeri.re.kr; Hur, Min Goo; Yang, Seung Dae [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong, Jeongup-si, 580-185 Jeollabuk-do (Korea, Republic of); Yu, Kook Hyun [Department of Chemistry, Dongguk University, 3 Pildong, Chunggu, Seoul 100-715 (Korea, Republic of)], E-mail: yukook@dongguk.edu

    2009-07-15

    Soy germ was irradiated with 2 MeV electron beam with different doses ranging from 1 to 20 kGy. The amount of isoflavones from irradiated soy germ was compared with those from natural soy germ by extracting with ethanol and methanol. The changed amounts of isoflavones were measured by high-performance liquid chromatography with standard calibration curve. Each extract of soy germ was quantified for antioxidant activity with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging method. The amount of isoflavones was found to be increased after electron-beam irradiation. Particularly ethanol extract with 15 kGy irradiated soy germ contained the maximum amount of isoflavones. Antioxidant activity of irradiated soy germ was higher than that of natural soy germ.

  1. Immunohistochemical expression of embryonal marker TRA-1-60 in carcinoma in situ and germ cell tumors of the testis

    DEFF Research Database (Denmark)

    Giwercman, Alexander; Andrews, P W; Jørgensen, N

    1993-01-01

    Testicular cancer is preceded by the noninvasive stage of carcinoma in situ (CIS). According to a recent hypothesis, testicular CIA cells are germ cells transformed in fetal life. The idea of an embryonal origin of testicular germ cell neoplasia would be strengthened by the finding of antigenic s...... similarity between fetal germ cells, CIS cells, and invasive testicular germ cell tumors....

  2. The Aster code; Code Aster

    Energy Technology Data Exchange (ETDEWEB)

    Delbecq, J.M

    1999-07-01

    The Aster code is a 2D or 3D finite-element calculation code for structures developed by the R and D direction of Electricite de France (EdF). This dossier presents a complete overview of the characteristics and uses of the Aster code: introduction of version 4; the context of Aster (organisation of the code development, versions, systems and interfaces, development tools, quality assurance, independent validation); static mechanics (linear thermo-elasticity, Euler buckling, cables, Zarka-Casier method); non-linear mechanics (materials behaviour, big deformations, specific loads, unloading and loss of load proportionality indicators, global algorithm, contact and friction); rupture mechanics (G energy restitution level, restitution level in thermo-elasto-plasticity, 3D local energy restitution level, KI and KII stress intensity factors, calculation of limit loads for structures), specific treatments (fatigue, rupture, wear, error estimation); meshes and models (mesh generation, modeling, loads and boundary conditions, links between different modeling processes, resolution of linear systems, display of results etc..); vibration mechanics (modal and harmonic analysis, dynamics with shocks, direct transient dynamics, seismic analysis and aleatory dynamics, non-linear dynamics, dynamical sub-structuring); fluid-structure interactions (internal acoustics, mass, rigidity and damping); linear and non-linear thermal analysis; steels and metal industry (structure transformations); coupled problems (internal chaining, internal thermo-hydro-mechanical coupling, chaining with other codes); products and services. (J.S.)

  3. ANIMAL code

    Energy Technology Data Exchange (ETDEWEB)

    Lindemuth, I.R.

    1979-02-28

    This report describes ANIMAL, a two-dimensional Eulerian magnetohydrodynamic computer code. ANIMAL's physical model also appears. Formulated are temporal and spatial finite-difference equations in a manner that facilitates implementation of the algorithm. Outlined are the functions of the algorithm's FORTRAN subroutines and variables.

  4. Network Coding

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Network Coding. K V Rashmi Nihar B Shah P Vijay Kumar. General Article Volume 15 Issue 7 July 2010 pp 604-621. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/015/07/0604-0621 ...

  5. ANIMAL code

    International Nuclear Information System (INIS)

    Lindemuth, I.R.

    1979-01-01

    This report describes ANIMAL, a two-dimensional Eulerian magnetohydrodynamic computer code. ANIMAL's physical model also appears. Formulated are temporal and spatial finite-difference equations in a manner that facilitates implementation of the algorithm. Outlined are the functions of the algorithm's FORTRAN subroutines and variables

  6. Expander Codes

    Indian Academy of Sciences (India)

    Codes and Channels. A noisy communication channel is illustrated in Fig- ... nication channel. Suppose we want to transmit a message over the unreliable communication channel so that even if the channel corrupts some of the bits we are able to recover ..... is d-regular, meaning thereby that every vertex has de- gree d.

  7. Expander Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 1. Expander Codes - The Sipser–Spielman Construction. Priti Shankar. General Article Volume 10 ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science Bangalore 560 012, India.

  8. Network Coding

    Indian Academy of Sciences (India)

    Network coding is a technique to increase the amount of information °ow in a network by mak- ing the key observation that information °ow is fundamentally different from commodity °ow. Whereas, under traditional methods of opera- tion of data networks, intermediate nodes are restricted to simply forwarding their incoming.

  9. High efficiency germ-line transformation of mosquitoes.

    Science.gov (United States)

    Lobo, Neil F; Clayton, John R; Fraser, Malcolm J; Kafatos, Fotis C; Collins, Frank H

    2006-01-01

    The ability to manipulate the mosquito genome through germ-line transformation provides us with a powerful tool for investigating gene structure and function. It is also a valuable method for the development of novel approaches to combating the spread of mosquito-vectored diseases. To date, germ-line transformation has been demonstrated in several mosquito species. Transgenes are introduced into pre-blastocyst mosquito embryos using microinjection techniques that take a few hours, and progeny are screened for the presence of a marker gene. The microinjection protocol presented here can be applied to most mosquitoes and contains several improvements over other published methods that increase the survival of injected embryos and, therefore, the number of transformants. Transgenic lines can be established in approximately 1 month using this technique.

  10. Impact of primary metastatic bone disease in germ cell tumors

    DEFF Research Database (Denmark)

    Oing, C; Oechsle, K; Necchi, A

    2017-01-01

    Background: Bone metastases (BM) are rare in germ cell tumor (GCT) patients. Systematic data on risk factors, treatment and outcome are largely lacking. Patients and methods: A database created by an international consortium including 123 GCT patients with BM at primary diagnosis was retrospectiv......Background: Bone metastases (BM) are rare in germ cell tumor (GCT) patients. Systematic data on risk factors, treatment and outcome are largely lacking. Patients and methods: A database created by an international consortium including 123 GCT patients with BM at primary diagnosis...... prognosticators in univariate analysis were a mediastinal primary (PFS; HR 1.92; 95%CI, 1.05-3.50; OS; HR 2.16; 95%CI, 1.14-4.09) and the presence of liver and/or brain metastases (PFS; HR 1.89; 95%CI, 1.13-3.17; OS; HR 1.91; 95%CI, 0.024) Seminomatous histology was the strongest predictor for favorable PFS...

  11. MRI Findings of Suprasellar Germ Cell Tumors in Two Dogs.

    Science.gov (United States)

    Cook, Laurie; Tensley, Michelle; Drost, Wm Tod; Koivisto, Christopher; Oglesbee, Michael

    2018-03-20

    A 4 yr old border collie presenting for mydriasis and decreased mentation and a 7 yr old Boston terrier presenting for obtundation, head tilt, and paraparesis were both evaluated using MRI. Findings in both included mass lesions of the thalamus and brainstem that were hypo- to isointense on T1-weighted images and hyperintense on T2-weighted images with regions of hypointensity, and robust contrast enhancement and displacement of adjacent structures. Postmortem histopathology findings, tumor location, and a mixed pattern of epithelial cell differentiation were consistent with germ cell tumor in both cases. Germ cell tumor of the suprasellar region is an infrequently reported neoplasm of dogs and imaging findings in this species have not been well described in the prior literature.

  12. Mediastinal germ cell tumors: a radiologic-pathologic review

    Energy Technology Data Exchange (ETDEWEB)

    Drevelegas, A. [Dept. of Radiology, Aristoteles Univ., Thessaloniki (Greece); Palladas, P. [Dept. of Radiology, G. Papanicolaou Hospital, Thessaloniki (Greece); Scordalaki, A. [Dept. of Pathology, G. Papanicolaou Hospital, Thessaloniki (Greece)

    2001-10-01

    Germ cell tumors of the mediastinum are histologically identical to those found in the testes and ovaries. Early diagnosis and treatment improve the survival rate. Imaging studies of teratoma demonstrate a rounded, often lobulated heterogeneous mass containing soft tissue elements with fluid and fat attenuation. Calcification is present in 20-43% of cases. Seminomas are large masses of homogeneous soft tissue attenuation. Malignant nonseminomatous germ cell tumors are heterogeneous tumors with irregular borders due to invasion of adjacent structures. CT shows the location and extent of the tumors as well as intrinsic elements including soft tissue, fat, fluid, and calcification. CT is the modality of choice for the diagnostic evaluation of these tumors. MRI reveals masses of heterogeneous signal intensity, is more sensitive in depicting infiltration of the adjacent structures by fat plane obliteration, and is performed as an ancillary study. (orig.)

  13. Un recuerdo norteamericano de Germán Vargas

    Directory of Open Access Journals (Sweden)

    Raymond L. Williams

    1991-01-01

    Full Text Available El maestro Germán Vargas fue un muy querido amigo: pero era mucho más que un amigo: fue la persona más generosa que he conocido. Fue el mentor de varias generaciones de intelectuales colombianos y extranjeros. Sin él, Colombia sería mucho menos de lo que es; sin él, todos los que lo hemos conocido seríamos menos de lo que somos.

  14. Towards Optimal Diagnosis of Type II Germ Cell Tumors

    OpenAIRE

    Stoop, Hans

    2011-01-01

    textabstractThe aim of the work described in this thesis is to improve the understanding of the pathobiology of testicular cancer (type II Germ Cell Tumors) to create possibilities for optimalization of diagnosis for this type of malignancy in routine pathology laboratories. The different studies presented here show valuable additional information on the microscopic diagnostics in daily practice. This enables proper and complete diagnosis of this relative rare variant of cancer ensuring the b...

  15. Biochemical Intestinal Parameters in Germ-free Minipigs and Rats and in Ex-germ-free Minipigs and Rats Monoassociated with Escherichia coli

    Czech Academy of Sciences Publication Activity Database

    Cardona, M.,E.; Kozáková, Hana; Collinder, E.; Persson, A.-K.; Midtvedt, T.; Norin, E.

    2005-01-01

    Roč. 52, - (2005), s. 109-113 ISSN 1548-9213 R&D Projects: GA AV ČR IAA5020101 Institutional research plan: CEZ:AV0Z5020903 Keywords : germ-free * minipigs * ex-germ-free Subject RIV: EE - Microbiology, Virology Impact factor: 2.111, year: 2005

  16. Panda code

    International Nuclear Information System (INIS)

    Altomare, S.; Minton, G.

    1975-02-01

    PANDA is a new two-group one-dimensional (slab/cylinder) neutron diffusion code designed to replace and extend the FAB series. PANDA allows for the nonlinear effects of xenon, enthalpy and Doppler. Fuel depletion is allowed. PANDA has a completely general search facility which will seek criticality, maximize reactivity, or minimize peaking. Any single parameter may be varied in a search. PANDA is written in FORTRAN IV, and as such is nearly machine independent. However, PANDA has been written with the present limitations of the Westinghouse CDC-6600 system in mind. Most computation loops are very short, and the code is less than half the useful 6600 memory size so that two jobs can reside in the core at once. (auth)

  17. Characterizing the mechanical behavior of the zebrafish germ layers

    Science.gov (United States)

    Kealhofer, David; Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Lucio, Adam; Campàs, Otger

    Organ morphogenesis and the development of the animal body plan involve complex spatial and temporal control of tissue- and cell-level mechanics. A prime example is the generation of stresses by individual cells to reorganize the tissue. These processes have remained poorly understood due to a lack of techniques to characterize the local constitutive law of the material, which relates local cellular forces to the resulting tissue flows. We have developed a method for quantitative, local in vivo study of material properties in living tissue using magnetic droplet probes. We use this technique to study the material properties of the different zebrafish germ layers using aggregates of zebrafish mesendodermal and ectodermal cells as a model system. These aggregates are ideal for controlled studies of the mechanics of individual germ layers because of the homogeneity of the cell type and the simple spherical geometry. Furthermore, the numerous molecular tools and transgenic lines already developed for this model organism can be applied to these aggregates, allowing us to characterize the contributions of cell cortex tension and cell adhesion to the mechanical properties of the zebrafish germ layers.

  18. Gene expression profiling of chicken primordial germ cell ESTs

    Directory of Open Access Journals (Sweden)

    Lim Dajeong

    2006-08-01

    Full Text Available Abstract Background Germ cells are the only cell type that can penetrate from one generation to next generation. At the early embryonic developmental stages, germ cells originally stem from primordial germ cells, and finally differentiate into functional gametes, sperm in male or oocyte in female, after sexual maturity. This study was conducted to investigate a large-scale expressed sequence tag (EST analysis in chicken PGCs and compare the expression of the PGC ESTs with that of embryonic gonad. Results We constructed 10,851 ESTs from a chicken cDNA library of a collection of highly separated embryonic PGCs. After chimeric and problematic sequences were filtered out using the chicken genomic sequences, there were 5,093 resulting unique sequences consisting of 156 contigs and 4,937 singlets. Pearson chi-square tests of gene ontology terms in the 2nd level between PGC and embryonic gonad set showed no significance. However, digital gene expression profiling using the Audic's test showed that there were 2 genes expressed significantly with higher number of transcripts in PGCs compared with the embryonic gonads set. On the other hand, 17 genes in embryonic gonads were up-regulated higher than those in the PGC set. Conclusion Our results in this study contribute to knowledge of mining novel transcripts and genes involved in germline cell proliferation and differentiation at the early embryonic stages.

  19. Characteristic promoter hypermethylation signatures in male germ cell tumors

    Directory of Open Access Journals (Sweden)

    Bosl George J

    2002-11-01

    Full Text Available Abstract Background Human male germ cell tumors (GCTs arise from undifferentiated primordial germ cells (PGCs, a stage in which extensive methylation reprogramming occurs. GCTs exhibit pluripotentality and are highly sensitive to cisplatin therapy. The molecular basis of germ cell (GC transformation, differentiation, and exquisite treatment response is poorly understood. Results To assess the role and mechanism of promoter hypermethylation, we analyzed CpG islands of 21 gene promoters by methylation-specific PCR in seminomatous (SGCT and nonseminomatous (NSGCT GCTs. We found 60% of the NSGCTs demonstrating methylation in one or more gene promoters whereas SGCTs showed a near-absence of methylation, therefore identifying distinct methylation patterns in the two major histologies of GCT. DNA repair genes MGMT, RASSF1A, and BRCA1, and a transcriptional repressor gene HIC1, were frequently methylated in the NSGCTs. The promoter hypermethylation was associated with gene silencing in most methylated genes, and reactivation of gene expression occured upon treatment with 5-Aza-2' deoxycytidine in GCT cell lines. Conclusions Our results, therefore, suggest a potential role for epigenetic modification of critical tumor suppressor genes in pathways relevant to GC transformation, differentiation, and treatment response.

  20. Cryopreservation of specialized chicken lines using cultured primordial germ cells.

    Science.gov (United States)

    Nandi, S; Whyte, J; Taylor, L; Sherman, A; Nair, V; Kaiser, P; McGrew, M J

    2016-08-01

    Biosecurity and sustainability in poultry production requires reliable germplasm conservation. Germplasm conservation in poultry is more challenging in comparison to other livestock species. Embryo cryopreservation is not feasible for egg-laying animals, and chicken semen conservation has variable success for different chicken breeds. A potential solution is the cryopreservation of the committed diploid stem cell precursors to the gametes, the primordial germ cells ( PGCS: ). Primordial germ cells are the lineage-restricted cells found at early embryonic stages in birds and form the sperm and eggs. We demonstrate here, using flocks of partially inbred, lower-fertility, major histocompatibility complex- ( MHC-: ) restricted lines of chicken, that we can easily derive and cryopreserve a sufficient number of independent lines of male and female PGCs that would be sufficient to reconstitute a poultry breed. We demonstrate that germ-line transmission can be attained from these PGCs using a commercial layer line of chickens as a surrogate host. This research is a major step in developing and demonstrating that cryopreserved PGCs could be used for the biobanking of specialized flocks of birds used in research settings. The prospective application of this technology to poultry production will further increase sustainability to meet current and future production needs. © The Author 2016. Published by Oxford University Press on behalf of Poultry Science Association.

  1. Progress towards human primordial germ cell specification in vitro.

    Science.gov (United States)

    Canovas, S; Campos, R; Aguilar, E; Cibelli, J B

    2017-01-01

    Primordial germ cells (PGCs) have long been considered the link between one generation and the next. PGC specification begins in the early embryo as a result of a highly orchestrated combination of transcriptional and epigenetic mechanisms. Understanding the molecular events that lead to proper PGC development will facilitate the development of new treatments for human infertility as well as species conservation. This article describes the latest, most relevant findings about the mechanisms of PGC formation, emphasizing human PGC. It also discusses our own laboratory's progress in using transdifferentiation protocols to derive human PGCs (hPGCs). Our preliminary results arose from our pursuit of a sequential hPGC induction strategy that starts with the repression of lineage-specific factors in the somatic cell, followed by the reactivation of germ cell-related genes using specific master regulators, which can indeed reactivate germ cell-specific genes in somatic cells. While it is still premature to assume that fully functional human gametes can be obtained in a dish, our results, together with those recently published by others, provide strong evidence that generating their precursors, PGCs, is within reach. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. X chromosome activity in mouse XX primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Susana M Chuva de Sousa Lopes

    2008-02-01

    Full Text Available In the early epiblast of female mice, one of the two X chromosomes is randomly inactivated by a Xist-dependent mechanism, involving the recruitment of Ezh2-Eed and the subsequent trimethylation of histone 3 on lysine 27 (H3K27me3. We demonstrate that this random inactivation process applies also to the primordial germ cell (PGC precursors, located in the proximal region of the epiblast. PGC specification occurs at about embryonic day (E7.5, in the extraembryonic mesoderm, after which the germ cells enter the endoderm of the invaginating hindgut. As they migrate towards the site of the future gonads, the XX PGCs gradually lose the H3K27me3 accumulation on the silent X chromosome. However, using a GFP transgene inserted into the X chromosome, we observed that the XX gonadal environment (independently of the gender is important for the substantial reactivation of the inactive X chromosome between E11.5 and E13.5, but is not required for X-chromosome reactivation during the derivation of pluripotent embryonic germ cells. We describe in detail one of the key events during female PGC development, the epigenetic reprogramming of the X chromosome, and demonstrate the role of the XX somatic genital ridge in this process.

  3. Giant Mediastinal Germ Cell Tumour: An Enigma of Surgical Consideration

    Directory of Open Access Journals (Sweden)

    Firdaus Hayati

    2016-01-01

    Full Text Available We present a case of 16-year-old male, who was referred from private centre for dyspnoea, fatigue, and orthopnea. The chest radiograph revealed complete opacification of left chest which was confirmed by computed tomography as a large left mediastinal mass measuring 14 × 15 × 18 cm. The diagnostic needle core biopsy revealed mixed germ cell tumour with possible combination of embryonal carcinoma, yolk sac, and teratoma. After 4 cycles of neoadjuvant BEP regime, there was initial response of tumour markers but not tumour bulk. Instead of classic median sternotomy or clamshell incision, posterolateral approach with piecemeal manner was chosen. Histology confirmed mixed germ cell tumour with residual teratomatous component without yolk sac or embryonal carcinoma component. Weighing 3.5 kg, it is one of the largest mediastinal germ cell tumours ever reported. We describe this rare and gigantic intrathoracic tumour and discuss the spectrum of surgical approach and treatment of this exceptional tumour.

  4. Tre1, a G protein-coupled receptor, directs transepithelial migration of Drosophila germ cells.

    Directory of Open Access Journals (Sweden)

    Prabhat S Kunwar

    2003-12-01

    Full Text Available In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR, Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target.

  5. The diversity of nanos expression in echinoderm embryos supports different mechanisms in germ cell specification.

    Science.gov (United States)

    Fresques, Tara; Swartz, Steven Zachary; Juliano, Celina; Morino, Yoshiaki; Kikuchi, Mani; Akasaka, Koji; Wada, Hiroshi; Yajima, Mamiko; Wessel, Gary M

    2016-07-01

    Specification of the germ cell lineage is required for sexual reproduction in all animals. However, the timing and mechanisms of germ cell specification is remarkably diverse in animal development. Echinoderms, such as sea urchins and sea stars, are excellent model systems to study the molecular and cellular mechanisms that contribute to germ cell specification. In several echinoderm embryos tested, the germ cell factor Vasa accumulates broadly during early development and is restricted after gastrulation to cells that contribute to the germ cell lineage. In the sea urchin, however, the germ cell factor Vasa is restricted to a specific lineage by the 32-cell stage. We therefore hypothesized that the germ cell specification program in the sea urchin/Euechinoid lineage has evolved to an earlier developmental time point. To test this hypothesis we determined the expression pattern of a second germ cell factor, Nanos, in four out of five extant echinoderm clades. Here we find that Nanos mRNA does not accumulate until the blastula stage or later during the development of all other echinoderm embryos except those that belong to the Echinoid lineage. Instead, Nanos is expressed in a restricted domain at the 32-128 cell stage in Echinoid embryos. Our results support the model that the germ cell specification program underwent a heterochronic shift in the Echinoid lineage. A comparison of Echinoid and non-Echinoid germ cell specification mechanisms will contribute to our understanding of how these mechanisms have changed during animal evolution. © 2016 Wiley Periodicals, Inc.

  6. Germ cell development in the Honeybee (Apis mellifera; Vasa and Nanos expression

    Directory of Open Access Journals (Sweden)

    Dearden Peter K

    2006-02-01

    Full Text Available Abstract Background Studies of specification of germ-cells in insect embryos has indicated that in many taxa the germ cells form early in development, and their formation is associated with pole plasm, germ plasm or an organelle called the oosome. None of these morphological features associated with germ cell formation have been identified in the Honeybee Apis mellifera. In this study I report the cloning and expression analysis of Honeybee homologues of vasa and nanos, germ cell markers in insects and other animals. Results Apis vasa and nanos RNAs are present in early honeybee embryos, but the RNAs clear rapidly, without any cells expressing these germ cell markers past stage 2. These genes are then only expressed in a line of cells in the abdomen from stage 9 onwards. These cells are the developing germ cells that are moved dorsally by dorsal closure and are placed in the genital ridge. Conclusion This study of the expression of germ cell markers in the honeybee implies that in this species either germ cells are formed by an inductive event, late in embryogenesis, or they are formed early in development in the absence of vasa and nanos expression. This contrasts with germ cell development in other members of the Hymenoptera, Diptera and Lepidoptera.

  7. Bilateral testicular germ cell tumors: twenty-year experience at M. D. Anderson Cancer Center.

    Science.gov (United States)

    Che, Mingxin; Tamboli, Pheroze; Ro, Jae Y; Park, Dong Soo; Ro, Jung Sil; Amato, Robert J; Ayala, Alberto G

    2002-09-15

    The incidence of testicular carcinoma in the United States has increased significantly over the last two decades. Germ cell tumors form the majority of malignant testicular tumors. With advances in diagnosis and therapeutic approaches, germ cell tumors are now highly sensitive to treatment, providing long-term survival. It has been speculated that the incidence of bilateral germ cell tumors may increase due to the improved survival of patients with unilateral germ cell tumors. In this report, the authors present a study of bilateral germ cell tumors of the testis in men who were treated at The University of Texas M. D. Anderson Cancer Center over a 20-year period with emphasis on their incidence, histologic features, and clinical features. Between 1978 and 1999, 2431 patients with testicular germ cell tumors were treated at The University of Texas M. D. Anderson Cancer Center. Among these, 24 patients with bilateral germ cell tumors were identified. Clinical records and all available pathology slides of the tumors were reviewed. The overall incidence of bilateral germ cell tumors in the patients with testicular germ cell tumors was 1% (24 of 2431 patients). The incidence was 1.8% (14 of 776 patients) in patients with seminoma and 0.6% (10 of 1655 patients) in patients with nonseminomatous germ cell tumors. Patients with seminoma who were age presentation in patients with seminoma. Thus, patients in the second or third decade of life who presented with seminomas as their initial tumor were more likely to develop a second germ cell tumor compared with patients in the fourth or fifth decade of life. These findings have potentially important implications for clinical management by identifying a population of patients with germ cell tumors who are at risk of developing a second tumor and also for studying risk factors of bilateral germ cell tumors of the testis. Copyright 2002 American Cancer Society.

  8. FLI-1 Flightless-1 and LET-60 Ras control germ line morphogenesis in C. elegans

    Directory of Open Access Journals (Sweden)

    Dentler William L

    2008-05-01

    Full Text Available Abstract Background In the C. elegans germ line, syncytial germ line nuclei are arranged at the cortex of the germ line as they exit mitosis and enter meiosis, forming a nucleus-free core of germ line cytoplasm called the rachis. Molecular mechanisms of rachis formation and germ line organization are not well understood. Results Mutations in the fli-1 gene disrupt rachis organization without affecting meiotic differentiation, a phenotype in C. elegans referred to here as the germ line morphogenesis (Glm phenotype. In fli-1 mutants, chains of meiotic germ nuclei spanned the rachis and were partially enveloped by invaginations of germ line plasma membrane, similar to nuclei at the cortex. Extensions of the somatic sheath cells that surround the germ line protruded deep inside the rachis and were associated with displaced nuclei in fli-1 mutants. fli-1 encodes a molecule with leucine-rich repeats and gelsolin repeats similar to Drosophila flightless 1 and human Fliih, which have been shown to act as cytoplasmic actin regulators as well as nuclear transcriptional regulators. Mutations in let-60 Ras, previously implicated in germ line development, were found to cause the Glm phenotype. Constitutively-active LET-60 partially rescued the fli-1 Glm phenotype, suggesting that LET-60 Ras and FLI-1 might act together to control germ line morphogenesis. Conclusion FLI-1 controls germ line morphogenesis and rachis organization, a process about which little is known at the molecular level. The LET-60 Ras GTPase might act with FLI-1 to control germ line morphogenesis.

  9. In vitro differentiation of germ cells from stem cells: a comparison between primordial germ cells and in vitro derived primordial germ cell-like cells.

    Science.gov (United States)

    Ge, W; Chen, C; De Felici, M; Shen, W

    2015-10-15

    Stem cells are unique cell types capable to proliferate, some of them indefinitely, while maintaining the ability to differentiate into a few or any cell lineages. In 2003, a group headed by Hans R. Schöler reported that oocyte-like cells could be produced from mouse embryonic stem (ES) cells in vitro. After more than 10 years, where have these researches reached? Which are the major successes achieved and the problems still remaining to be solved? Although during the last years, many reviews have been published about these topics, in the present work, we will focus on an aspect that has been little considered so far, namely a strict comparison between the in vitro and in vivo developmental capabilities of the primordial germ cells (PGCs) isolated from the embryo and the PGC-like cells (PGC-LCs) produced in vitro from different types of stem cells in the mouse, the species in which most investigation has been carried out. Actually, the formation and differentiation of PGCs are crucial for both male and female gametogenesis, and the faithful production of PGCs in vitro represents the basis for obtaining functional germ cells.

  10. Distinct requirements for energy metabolism in mouse primordial germ cells and their reprogramming to embryonic germ cells.

    Science.gov (United States)

    Hayashi, Yohei; Otsuka, Kei; Ebina, Masayuki; Igarashi, Kaori; Takehara, Asuka; Matsumoto, Mitsuyo; Kanai, Akio; Igarashi, Kazuhiko; Soga, Tomoyoshi; Matsui, Yasuhisa

    2017-08-01

    Primordial germ cells (PGCs), undifferentiated embryonic germ cells, are the only cells that have the ability to become gametes and to reacquire totipotency upon fertilization. It is generally understood that the development of PGCs proceeds through the expression of germ cell-specific transcription factors and characteristic epigenomic changes. However, little is known about the properties of PGCs at the metabolite and protein levels, which are directly responsible for the control of cell function. Here, we report the distinct energy metabolism of PGCs compared with that of embryonic stem cells. Specifically, we observed remarkably enhanced oxidative phosphorylation (OXPHOS) and decreased glycolysis in embryonic day 13.5 (E13.5) PGCs, a pattern that was gradually established during PGC differentiation. We also demonstrate that glycolysis and OXPHOS are important for the control of PGC reprogramming and specification of pluripotent stem cells (PSCs) into PGCs in culture. Our findings about the unique metabolic property of PGCs provide insights into our understanding of the importance of distinct facets of energy metabolism for switching PGC and PSC status.

  11. Successful Reconstruction of Tooth Germ with Cell Lines Requires Coordinated Gene Expressions from the Initiation Stage

    Directory of Open Access Journals (Sweden)

    Yasuhiro Tomooka

    2012-10-01

    Full Text Available Tooth morphogenesis is carried out by a series of reciprocal interactions between the epithelium and mesenchyme in embryonic germs. Previously clonal dental epithelial cell (epithelium of molar tooth germ (emtg lines were established from an embryonic germ. They were odontogenic when combined with a dental mesenchymal tissue, although the odontogenesis was quantitatively imperfect. To improve the microenvironment in the germs, freshly isolated dental epithelial cells were mixed with cells of lines, and germs were reconstructed in various combinations. The results demonstrated that successful tooth construction depends on the mixing ratio, the age of dental epithelial cells and the combination with cell lines. Analyses of gene expression in these germs suggest that some signal(s from dental epithelial cells makes emtg cells competent to communicate with mesenchymal cells and the epithelial and mesenchymal compartments are able to progress  odontogenesis from the initiation stage.

  12. Primordial germ cells: the first cell lineage or the last cells standing?

    Science.gov (United States)

    Johnson, Andrew D; Alberio, Ramiro

    2015-08-15

    Embryos of many animal models express germ line determinants that suppress transcription and mediate early germ line commitment, which occurs before the somatic cell lineages are established. However, not all animals segregate their germ line in this manner. The 'last cell standing' model describes primordial germ cell (PGC) development in axolotls, in which PGCs are maintained by an extracellular signalling niche, and germ line commitment occurs after gastrulation. Here, we propose that this 'stochastic' mode of PGC specification is conserved in vertebrates, including non-rodent mammals. We postulate that early germ line segregation liberates genetic regulatory networks for somatic development to evolve, and that it therefore emerged repeatedly in the animal kingdom in response to natural selection. © 2015. Published by The Company of Biologists Ltd.

  13. Forskolin and the meiosis inducing substance synergistically initiate meiosis in fetal male germ cells

    DEFF Research Database (Denmark)

    Byskov, A G; Fenger, M; Westergaard, L

    1993-01-01

    are fixed, squashed, and DNA-stained. In these preparations germ cells and somatic cells can be distinguished, and the number of germ cells in the different stages of meiosis is counted as is the number of somatic cells in mitosis. MIS activity is defined to be present in a medium when meiosis is induced......We have shown that Meiosis Inducing Substance (MIS) and forskolin synergistically and dose dependently induce meiosis in germ cells of cultured fetal mouse testes. We used a bioassay which consists of fetal mouse testes and ovaries cultured for 6 days. In this study MIS media are spent culture...... in male germ cells during culture. We found that MIS media as well as forskolin induced meiosis in fetal male germ cells in a dose-dependent manner. In addition, MIS media and forskolin acted synergistically by inducing meiosis. Female germ cells seem to be unaffected by the various culture media...

  14. From concatenated codes to graph codes

    DEFF Research Database (Denmark)

    Justesen, Jørn; Høholdt, Tom

    2004-01-01

    We consider codes based on simple bipartite expander graphs. These codes may be seen as the first step leading from product type concatenated codes to more complex graph codes. We emphasize constructions of specific codes of realistic lengths, and study the details of decoding by message passing...

  15. Dicer1 depletion in male germ cells leads to infertility due to cumulative meiotic and spermiogenic defects.

    Directory of Open Access Journals (Sweden)

    Yannick Romero

    Full Text Available BACKGROUND: Spermatogenesis is a complex biological process that requires a highly specialized control of gene expression. In the past decade, small non-coding RNAs have emerged as critical regulators of gene expression both at the transcriptional and post-transcriptional level. DICER1, an RNAse III endonuclease, is essential for the biogenesis of several classes of small RNAs, including microRNAs (miRNAs and endogenous small interfering RNAs (endo-siRNAs, but is also critical for the degradation of toxic transposable elements. In this study, we investigated to which extent DICER1 is required for germ cell development and the progress of spermatogenesis in mice. PRINCIPAL FINDINGS: We show that the selective ablation of Dicer1 at the early onset of male germ cell development leads to infertility, due to multiple cumulative defects at the meiotic and post-meiotic stages culminating with the absence of functional spermatozoa. Alterations were observed in the first spermatogenic wave and include delayed progression of spermatocytes to prophase I and increased apoptosis, resulting in a reduced number of round spermatids. The transition from round to mature spermatozoa was also severely affected, since the few spermatozoa formed in mutant animals were immobile and misshapen, exhibiting morphological defects of the head and flagellum. We also found evidence that the expression of transposable elements of the SINE family is up-regulated in Dicer1-depleted spermatocytes. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that DICER1 is dispensable for spermatogonial stem cell renewal and mitotic proliferation, but is required for germ cell differentiation through the meiotic and haploid phases of spermatogenesis.

  16. Fatty acid composition of maize germ oil from high-oil hybrids wet-milling processing

    Directory of Open Access Journals (Sweden)

    Jovanović Petar Lj.

    2005-01-01

    Full Text Available Maize germ was obtained by wet-milling laboratory processing of domestic high-oil maize hybrids. After separation, the germ was subjected to extraction of maize oil. Fatty acid composition of maize germ oil was determined by gas chromatography. The results showed very high levels of unsaturated fatty acids and a constant sum of oleic and linoleic acids in oils of different maize hybrids.

  17. Isolation and purification of wheat germ agglutinin and analysis of its properties

    Science.gov (United States)

    Wang, Han

    2017-12-01

    In this paper, the wheat germ agglutinin was isolated and purified by affinity chromatography of chicken ovomucoid as ligand. The physicochemical properties were analyzed. The chicken ovomucoid was isolated from egg white and conjugated to affinity chromatography column agarose gel to prepare affinity adsorbent. The crude extract of wheat germ was freezedried by affinity chromatography. The physicochemical properties were analyzed by SDSpolyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. And the relative molecular mass and isoelectric point of wheat germ agglutinin were obtained, and the high efficiency of purification of wheat germ agglutinin was proved by affinity chromatography.

  18. Insights into female germ cell biology: from in vivo development to in vitro derivations.

    Science.gov (United States)

    Jung, Dajung; Kee, Kehkooi

    2015-01-01

    Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis.

  19. Forskolin and the meiosis inducing substance synergistically initiate meiosis in fetal male germ cells

    DEFF Research Database (Denmark)

    Byskov, A G; Fenger, M; Westergaard, L

    1993-01-01

    We have shown that Meiosis Inducing Substance (MIS) and forskolin synergistically and dose dependently induce meiosis in germ cells of cultured fetal mouse testes. We used a bioassay which consists of fetal mouse testes and ovaries cultured for 6 days. In this study MIS media are spent culture...... in male germ cells during culture. We found that MIS media as well as forskolin induced meiosis in fetal male germ cells in a dose-dependent manner. In addition, MIS media and forskolin acted synergistically by inducing meiosis. Female germ cells seem to be unaffected by the various culture media...

  20. The Drosophila stonewall gene encodes a putative transcription factor essential for germ cell development.

    Science.gov (United States)

    Clark, K A; McKearin, D M

    1996-03-01

    The differentiation of Drosophila germ cells is a useful model for studying mechanisms of cell specification. We report the identification of a gene, stonewall, that is required for germ cell development. Mutations in stonewall block proper oocyte differentiation and frequently cause the presumptive oocyte to develop as a nurse cell. Eventually, germ cells degenerate apoptotically. Stonewall is a germ cell nuclear protein; Stonewall has a DNA binding domain that shows similarities to the Myb and Adf-1 transcription factors and has other features that suggest that it is a transcription activating factor. We suggest that Stonewall transcriptional regulation is essential in cystocytes for maturation into specialized nurse cells and oocyte.

  1. Peculiarities in the CT findings of germ cell tumors in various tumor localizations

    International Nuclear Information System (INIS)

    Tazoe, Makoto; Miyagami, Mitsusuke; Tsubokawa, Takashi

    1991-01-01

    The CT findings of 17 germ cell tumors were studied in relation to the locations of the tumor, the pathological diagnoses, and the tumor markers (AFP and HCG). Generally, the CT findings of germ cell tumors depended on the pathological diagnoses more strongly than on the location of the tumors. On plain CT of 7 germ cell tumors in the pineal region, all of them demonstrated heterogeneous findings. Hydrocephalus was seen in 6 cases (86%) and calcification in 6 cases (86%) of the germ cell tumors in the pineal region. Calcification and hydrocephalus that appeared more often than in other regions were characteristic of germ cell tumors of the pineal region. The germ cell tumors in the basal ganglia had a slightly homogenous high density, with small cysts and calcification in most of them on plain CT. On enhanced CT, the tumors were moderately enhanced in all cases located in the basal ganglia. Four cases of germ cell tumors located in the basal ganglia revealed the dilatation of lateral ventricle due to hemispheric atrophy in the tumor side. The germ cell tumors showing an increase in the tumor markers such as AFP and HCG, which were usually malignant germ cell tumors, were strongly enhanced on enhanced CT. (author)

  2. A new glycosylated dihydrophaseic acid from cacao germs (Theobroma cacao L.).

    Science.gov (United States)

    Sannohe, Yumiko; Gomi, Shuichi; Murata, Takashi; Ohyama, Makoto; Yonekura, Kumiko; Kanegae, Minoru; Koga, Jinichiro

    2011-01-01

    Cacao beans are composed of cacao nibs and germs. Although numerous chemical and physiological studies on cacao nib compounds have been reported, there is little information on cacao germ compounds. We therefore analyzed an extract from the cacao germ, and found two compounds that were specific to the germ. One of these two compounds was identified as the new glycosylated abscisic acid metabolite, dihydrophaseic acid-4'-O-6″-(β-ribofuranosyl)-β-glucopyranoside, and the other as the known compound, dihydrophaseic acid-4'-O-β-D-glucopyranoside.

  3. Cytology of mixed germ cell tumor with mediastinal metastasis

    Directory of Open Access Journals (Sweden)

    Dagli Adile

    2009-01-01

    Full Text Available Nonseminomatous germ cell tumors of the testis are common and are very aggressive malignant tumors. Most of the cases have metastases at the time of diagnosis, and involvement of the posterior mediastinum in particular is well known. A 33 year-old male patient presented with complaints of a swelling on the right side of the neck that had been growing for the last month, as well as shortness of breath and cough. His thoracic computed tomography (CT showed a 1.5 cm lymph node on the anterior mediastinum and a mass of about 11 x 10 x 8 cm extending from the right lung apex to the right hilus, with regular contours and without contrast enhancement. The patient, who was given the preliminary diagnosis of a mixture metastatic bronchial tumor plus lymphoma, was subjected to transthoracic fine needle aspiration cytology (FNAC. His abdominal CT revealed a hypodense, heterogeneous and cystic necrotic mass of about 10 x 7 x 5 cm that was para-aortic at the infrarenal level (initially predicted as a lymphoma. The patient, who could not be typed in his cytopathological examination, was diagnosed with malignant epithelial tumor and was recommended to undergo a genitourinary system examination. Upon finding a high alpha fetoprotein (AFP value, a scrotal ultra sonography was performed which showed a mass filling the right testis. Histopathological examination of the orchiectomy material resulted in the diagnosis of mixed germ cell tumor (60% mature teratoma and 40% yolk sac tumor. Even though metastatic lesions are mostly seen in the posterior mediastinum, our findings reveal that specimens obtained with FNAC from the anterior mediastinum bear discohesive, pleomorphic, small nuclei in epithelial cells with microvacoules in the cytoplasm. These cytopathological alterations in specimens from the anterior mediastinum might promote germ cell and yolk sac tumors.

  4. Gas-cooled reactor thermal-hydraulics using CAST3M and CRONOS2 codes

    International Nuclear Information System (INIS)

    Studer, E.; Coulon, N.; Stietel, A.; Damian, F.; Golfier, H.; Raepsaet, X.

    2003-01-01

    The CEA R and D program on advanced Gas Cooled Reactors (GCR) relies on different concepts: modular High Temperature Reactor (HTR), its evolution dedicated to hydrogen production (Very High Temperature Reactor) and Gas Cooled Fast Reactors (GCFR). Some key safety questions are related to decay heat removal during potential accident. This is strongly connected to passive natural convection (including gas injection of Helium, CO 2 , Nitrogen or Argon) or forced convection using active safety systems (gas blowers, heat exchangers). To support this effort, thermal-hydraulics computer codes will be necessary tools to design, enhance the performance and ensure a high safety level of the different reactors. Accurate and efficient modeling of heat transfer by conduction, convection or thermal radiation as well as energy storage are necessary requirements to obtain a high level of confidence in the thermal-hydraulic simulations. To achieve that goal a thorough validation process has to ve conducted. CEA's CAST3M code dedicated to GCR thermal-hydraulics has been validated against different test cases: academic interaction between natural convection and thermal radiation, small scale in-house THERCE experiments and large scale High Temperature Test Reactor benchmarks such as HTTR-VC benchmark. Coupling with neutronics is also an important modeling aspect for the determination of neutronic parameters such as neutronic coefficient (Doppler, moderator,...), critical position of control rods...CEA's CAST3M and CRONOS2 computer codes allow this coupling and a first example of coupled thermal-hydraulics/neutronics calculations has been performed. Comparison with experimental data will be the next step with High Temperature Test Reactor experimental results at nominal power

  5. Specification of germ layer identity in the chick gastrula

    Directory of Open Access Journals (Sweden)

    Cai Qin

    2007-07-01

    Full Text Available Abstract Background Chick definitive endoderm is an important source of signals that pattern the early embryo forming a central structure around which the body plan is constructed. Although the origin of definitive endoderm has been mapped in the chick, arising principally from rostral streak at elongating streak stages, it is not known when this layer first becomes fully committed to its germ layer fate, an important issue to resolve in light of its critical role in subsequent patterning of the early embryo. Results Through gene expression screening of chick gastrula, we identified molecular markers of definitive endoderm restricted to rostral (Sox17 and caudal (Gata5/6 regions, suggesting that at least two subpopulations of definitive endodermal cells exist during ingression. We show (1 that presumptive mesoderm cells migrate to the middle layer and remain mesenchymal when transplanted to rostral primitive streak, and prospective endoderm cells enter the lower layer and become epithelial when transplanted to caudal primitive streak; and (2 that presumptive endoderm cells and mesoderm cells lose normal gene expression (Sox17 and Wnt8c, respectively when transplanted outside of their normal position of origin. Moreover, when rostral or caudal primitive streak segments are transplanted into rostral blastoderm isolates (RBIs, both types of transplants express Sox17 4–6 hours later–consistent with their new position, regardless of their presumptive germ layer origin–and prospective mesoderm transplants, which normally express Wnt8c, turn off expression, suggesting that signals within the rostral blastoderm induce endoderm gene expression, and repress mesoderm gene expression, during gastrulation. Conclusion Our results demonstrate that germ layer identity is fixed at the time populations of endoderm and mesoderm cells ingress through the primitive streak, whereas their gene expression patterns remain labile. In addition, our results show that

  6. Germán Colmenares : una memoria personal

    Directory of Open Access Journals (Sweden)

    Jorge Orlando Melo

    1990-01-01

    Full Text Available Conocí a Germán Colmenares en una época que ya parece inverosímil: en 1957, en una breve visita a Bogotá, tropecé en las oficinas de un periódico estudiantil que dirigía Fernando Cepeda Ulloa con un bogotano de 19 años, de atuendo rosarista, que discutía con ironía y dominio precoz acerca de Ortega y Gasset, Max Scheler o Weber.

  7. Gods, Germs, and Petri Dishes: Toward a Nonsecular Medical Anthropology.

    Science.gov (United States)

    Roberts, Elizabeth F S

    2016-01-01

    This commentary calls on medical anthropology to become programmatically non-secular. Despite recent anthropological critiques of secularity, within and outside of anthropology, most contemporary medical anthropologists continue to leave deities and religiosity out of their examinations of healing practices, especially in their accounts of biomedicine. Through a critical, relational constructionist lens, which traces how all entities are both constructed and real, a non-secular medical anthropology would insist that when deities are part of medical practice, they are integral to analysis. Importantly then, within the symmetrical nature of this same constructionist lens, biomedical entities like germs and petri dishes need to be accounted for just as much as deities.

  8. Identification of genes expressed in the hermaphrodite germ line of C. elegans using SAGE

    Directory of Open Access Journals (Sweden)

    Holt Robert A

    2009-05-01

    Full Text Available Abstract Background Germ cells must progress through elaborate developmental stages from an undifferentiated germ cell to a fully differentiated gamete. Some of these stages include exiting mitosis and entering meiosis, progressing through the various stages of meiotic prophase, adopting either a male (sperm or female (oocyte fate, and completing meiosis. Additionally, many of the factors needed to drive embryogenesis are synthesized in the germ line. To increase our understanding of the genes that might be necessary for the formation and function of the germ line, we have constructed a SAGE library from hand dissected C. elegans hermaphrodite gonads. Results We found that 4699 genes, roughly 21% of all known C. elegans genes, are expressed in the adult hermaphrodite germ line. Ribosomal genes are highly expressed in the germ line; roughly four fold above their expression levels in the soma. We further found that 1063 of the germline-expressed genes have enriched expression in the germ line as compared to the soma. A comparison of these 1063 germline-enriched genes with a similar list of genes prepared using microarrays revealed an overlap of 460 genes, mutually reinforcing the two lists. Additionally, we identified 603 germline-enriched genes, supported by in situ expression data, which were not previously identified. We also found >4 fold enrichment for RNA binding proteins in the germ line as compared to the soma. Conclusion Using multiple technological platforms provides a more complete picture of global gene expression patterns. Genes involved in RNA metabolism are expressed at a significantly higher level in the germ line than the soma, suggesting a stronger reliance on RNA metabolism for control of the expression of genes in the germ line. Additionally, the number and expression level of germ line expressed genes on the X chromosome is lower than expected based on a random distribution.

  9. nanos function is essential for development and regeneration of planarian germ cells.

    Science.gov (United States)

    Wang, Yuying; Zayas, Ricardo M; Guo, Tingxia; Newmark, Phillip A

    2007-04-03

    Germ cells are required for the successful propagation of sexually reproducing species. Understanding the mechanisms by which these cells are specified and how their totipotency is established and maintained has important biomedical and evolutionary implications. Freshwater planarians serve as fascinating models for studying these questions. They can regenerate germ cells from fragments of adult tissues that lack reproductive structures, suggesting that inductive signaling is involved in planarian germ cell specification. To study the development and regeneration of planarian germ cells, we have functionally characterized an ortholog of nanos, a gene required for germ cell development in diverse organisms, from Schmidtea mediterranea. In the hermaphroditic strain of this species, Smed-nanos mRNA is detected in developing, regenerating, and mature ovaries and testes. However, it is not detected in the vast majority of newly hatched planarians or in small tissue fragments that will ultimately regenerate germ cells, consistent with an epigenetic origin of germ cells. We show that Smed-nanos RNA interference (RNAi) results in failure to develop, regenerate, or maintain gonads in sexual planarians. Unexpectedly, Smed-nanos mRNA is also detected in presumptive testes primordia of asexual individuals that reproduce strictly by fission. These presumptive germ cells are lost after Smed-nanos RNAi, suggesting that asexual planarians specify germ cells, but their differentiation is blocked downstream of Smed-nanos function. Our results reveal a conserved function of nanos in germ cell development in planarians and suggest that these animals will serve as useful models for dissecting the molecular basis of epigenetic germ cell specification.

  10. Non-germ cell tumours arising in germ cell tumours (teratoma with malignant transformation) in men: CT and MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Athanasiou, A. [Department of Radiology, Institut Gustave-Roussy, Villejuif (France); Department of Radiology, Institut Curie, Paris (France)], E-mail: alexandra.athanasiou@curie.net; Vanel, D. [Department of Radiology, Institut Gustave-Roussy, Villejuif (France); Department of Radiology, Istituti Ortopedici Rizzoli, Bologna (Italy); El Mesbahi, O. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France); Theodore, C. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France); Department of Oncology, Hopital Foch, Suresnes (France); Fizazi, K. [Department of Medicine, Institut Gustave-Roussy, Villejuif (France)

    2009-02-15

    Purpose: To describe the imaging findings of germ cell tumours (GCT) containing non-germ cell malignant components (also designated teratoma with malignant transformation or TMT). Patients and methods: The records of 14 male patients with GCT and a non-germ cell histological component TMT were retrospectively reviewed. All patients had computed tomography (CT) and/or magnetic resonance (MR) studies before and after initial surgery and chemotherapy, as well as during follow-up. Imaging findings were correlated with the response to treatment and with overall survival. Pathological evaluation, immunohistochemistry, serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were also taken into consideration. Sarcoma was identified in 10 out of 14 patients, with rhabdomyosarcoma ranking first (n = 4), followed by osteosarcoma (n = 2), fusiform cell sarcoma (n = 1), undifferentiated sarcoma (n = 1), neurosarcoma (n = 1) and myxoid sarcoma (n = 1). Other histological types of malignant transformation included adenocarcinoma (n = 3) and bronchoalveolar carcinoma (n = 1). Overall, 9 patients relapsed at a median time of 84 months (range 60-168). Results: Non-GCT malignant transformation was identified in the retroperitoneum (5), testis (3), mediastinum (3), peritoneum (2) and lungs (1). The CT and MR imaging findings before treatment and after relapse were evaluated with emphasis on imaging features that could possibly imply the presence of malignant transformation (heterogeneously enhancing soft-tissue masses, ossified masses with calcified lymph nodes, diffuse epiploic thickening associated with ascites and peritoneal nodules, pulmonary alveolar infiltration with septal thickening). All but 1 patient with TMT presented with nodal and distant metastases. The prognosis was poor: within a median follow-up of 59 months (range 3-180), 4 out of 14 patients were alive. Conclusion: TMT is rare and associated with poorer survival compared to GCT. Imaging can be useful

  11. Direct Reprogramming of Human Primordial Germ Cells into Induced Pluripotent Stem Cells: Efficient Generation of Genetically Engineered Germ Cells.

    Science.gov (United States)

    Bazley, Faith A; Liu, Cyndi F; Yuan, Xuan; Hao, Haiping; All, Angelo H; De Los Angeles, Alejandro; Zambidis, Elias T; Gearhart, John D; Kerr, Candace L

    2015-11-15

    Primordial germ cells (PGCs) share many properties with embryonic stem cells (ESCs) and innately express several key pluripotency-controlling factors, including OCT4, NANOG, and LIN28. Therefore, PGCs may provide a simple and efficient model for studying somatic cell reprogramming to induced pluripotent stem cells (iPSCs), especially in determining the regulatory mechanisms that fundamentally define pluripotency. Here, we report a novel model of PGC reprogramming to generate iPSCs via transfection with SOX2 and OCT4 using integrative lentiviral. We also show the feasibility of using nonintegrative approaches for generating iPSC from PGCs using only these two factors. We show that human PGCs express endogenous levels of KLF4 and C-MYC protein at levels similar to embryonic germ cells (EGCs) but lower levels of SOX2 and OCT4. Transfection with both SOX2 and OCT4 together was required to induce PGCs to a pluripotent state at an efficiency of 1.71%, and the further addition of C-MYC increased the efficiency to 2.33%. Immunohistochemical analyses of the SO-derived PGC-iPSCs revealed that these cells were more similar to ESCs than EGCs regarding both colony morphology and molecular characterization. Although leukemia inhibitory factor (LIF) was not required for the generation of PGC-iPSCs like EGCs, the presence of LIF combined with ectopic exposure to C-MYC yielded higher efficiencies. Additionally, the SO-derived PGC-iPSCs exhibited differentiation into representative cell types from all three germ layers in vitro and successfully formed teratomas in vivo. Several lines were generated that were karyotypically stable for up to 24 subcultures. Their derivation efficiency and survival in culture significantly supersedes that of EGCs, demonstrating their utility as a powerful model for studying factors regulating pluripotency in future studies.

  12. MASTL is essential for anaphase entry of proliferating primordial germ cells and establishment of female germ cells in mice.

    Science.gov (United States)

    Risal, Sanjiv; Zhang, Jingjing; Adhikari, Deepak; Liu, Xiaoman; Shao, Jingchen; Hu, Mengwen; Busayavalasa, Kiran; Tu, Zhaowei; Chen, Zijiang; Kaldis, Philipp; Liu, Kui

    2017-01-01

    In mammals, primordial germ cells (PGCs) are the embryonic cell population that serve as germ cell precursors in both females and males. During mouse embryonic development, the majority of PGCs are arrested at the G2 phase when they migrate into the hindgut at 7.75-8.75 dpc (days post coitum). It is after 9.5 dpc that the PGCs undergo proliferation with a doubling time of 12.6 h. The molecular mechanisms underlying PGC proliferation are however not well studied. In this work. Here we studied how MASTL (microtubule-associated serine/threonine kinase-like)/Greatwall kinase regulates the rapid proliferation of PGCs. We generated a mouse model where we specifically deleted Mastl in PGCs and found a significant loss of PGCs before the onset of meiosis in female PGCs. We further revealed that the deletion of Mastl in PGCs did not prevent mitotic entry, but led to a failure of the cells to proceed beyond metaphase-like stage, indicating that MASTL-mediated molecular events are indispensable for anaphase entry in PGCs. These mitotic defects further led to the death of Mastl -null PGCs by 12.5 dpc. Moreover, the defect in mitotic progression observed in the Mastl -null PGCs was rescued by simultaneous deletion of Ppp2r1a (α subunit of PP2A). Thus, our results demonstrate that MASTL, PP2A, and therefore regulated phosphatase activity have a fundamental role in establishing female germ cell population in gonads by controlling PGC proliferation during embryogenesis.

  13. Transgenesis and nuclear transfer using porcine embryonic germ cells.

    Science.gov (United States)

    Ahn, Kwang Sung; Won, Ji Young; Heo, Soon Young; Kang, Jee Hyun; Yang, Hong Seok; Shim, Hosup

    2007-01-01

    Embryonic germ (EG) cells are undifferentiated stem cells isolated from cultured primordial germ cells (PGC). Porcine EG cell lines with capacities of both in vitro and in vivo differentiation have been established. Because EG cells can be cultured indefinitely in an undifferentiated state, they may be more suitable for nuclear donor cells in nuclear transfer (NT) than somatic cells that have limited lifespan in primary culture. Use of EG cells could be particularly advantageous to provide an inexhaustible source of transgenic cells for NT. In this study the efficiencies of transgenesis and NT using porcine fetal fibroblasts and EG cells were compared. The rate of development to the blastocyst stage was significantly higher in EG cell NT than somatic cell NT (94 of 518, 18.2% vs. 72 of 501, 14.4%). To investigate if EG cells can be used for transgenesis in pigs, green fluorescent protein (GFP) gene was introduced into porcine EG cells. Nuclear transfer embryos using transfected EG cells gave rise to blastocysts (29 of 137, 21.2%) expressing GFP based on observation under fluorescence microscope. The results obtained from the present study suggest that EG cell NT may have advantages over somatic cell NT, and transgenic pigs may be produced using EG cells.

  14. Germ banks affect the inference of past demographic events.

    Science.gov (United States)

    Živković, Daniel; Tellier, Aurélien

    2012-11-01

    Continuous progress in empirical population genetics based on the whole-genome polymorphism data requires the theoretical analysis of refined models in order to interpret the evolutionary history of populations with adequate accuracy. Recent studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life-history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. Within this study, we investigate the combined effect of germ banking and time-varying population size on the neutral coalescent and particularly derive the allele frequency spectrum under some simplifying assumptions. We then perform an ABC analysis using two simple demographic scenarios-a population expansion and an instantaneous decline. We demonstrate the appreciable influence of seed banks on the estimation of demographic parameters depending on the germination rate with biases scaled by the square of the germination rate. In the more complex case of a population bottleneck, which comprises an instantaneous decline and an expansion phase, ignoring information on the germination rate denies reliable estimates of the bottleneck parameters via the allelic spectrum. In particular, when seeds remain in the bank over several generations, recent expansions may remain invisible in the frequency spectrum, whereas ancient declines leave signatures much longer than in the absence of seed bank. © 2012 Blackwell Publishing Ltd.

  15. Reconstitution of ovarian function following transplantation of primordial germ cells.

    Science.gov (United States)

    Zeng, Ming; Sheng, Xiaoyan; Keefe, David L; Liu, Lin

    2017-05-03

    Ovarian aging occurs earlier than somatic aging. We tested the hypothesis that ovarian functions could be artificially reconstructed by transplantation of primordial germ cells (PGCs). We compared various methods for transplantation of PGCs aggregated with gonadal somatic cells and showed that reconstituted ovaries exhibited folliculogenesis after transplantation of PGCs-aggregates into either kidney capsule or ovarian bursa. Neo-oogenesis occurred early after transplantation, as evidenced by the presence of prophase I meiocytes displaying homologous pairing. Moreover, endocrine function was recovered in ovariectomized recipients, including elevated levels of AMH and estradiol. Interestingly, folliculogenesis in the reconstituted ovaries failed to sustain past four weeks. Regardless of transplantation method, follicles diminished after 45 days, accompanied by increased apoptosis, and were undetectable after two months. Meanwhile, no replicative PGCs or prophase I meiocytes could be found. Together, transplantation of PGCs can effectively reconstitute ovarian functions but for limited time. These data suggest that PGCs do not undergo self-renewal but rapidly enter meiosis following transplantation. Global activation of primordial follicles in artificial ovaries can result in further rapid loss of germ cells. Methods for maintaining self-renewal and expansion in vivo of PGCs and controlling follicle activation will be essential for continuing maintenance of the functional reconstructed ovaries.

  16. Esrrb Complementation Rescues Development of Nanog-Null Germ Cells

    Directory of Open Access Journals (Sweden)

    Man Zhang

    2018-01-01

    Full Text Available The transcription factors (TFs Nanog and Esrrb play important roles in embryonic stem cells (ESCs and during primordial germ-cell (PGC development. Esrrb is a positively regulated direct target of NANOG in ESCs that can substitute qualitatively for Nanog function in ESCs. Whether this functional substitution extends to the germline is unknown. Here, we show that germline deletion of Nanog reduces PGC numbers 5-fold at midgestation. Despite this quantitative depletion, Nanog-null PGCs can complete germline development in contrast to previous findings. PGC-like cell (PGCLC differentiation of Nanog-null ESCs is also impaired, with Nanog-null PGCLCs showing decreased proliferation and increased apoptosis. However, induced expression of Esrrb restores PGCLC numbers as efficiently as Nanog. These effects are recapitulated in vivo: knockin of Esrrb to Nanog restores PGC numbers to wild-type levels and results in fertile adult mice. These findings demonstrate that Esrrb can replace Nanog function in germ cells.

  17. Automatic coding method of the ACR Code

    International Nuclear Information System (INIS)

    Park, Kwi Ae; Ihm, Jong Sool; Ahn, Woo Hyun; Baik, Seung Kook; Choi, Han Yong; Kim, Bong Gi

    1993-01-01

    The authors developed a computer program for automatic coding of ACR(American College of Radiology) code. The automatic coding of the ACR code is essential for computerization of the data in the department of radiology. This program was written in foxbase language and has been used for automatic coding of diagnosis in the Department of Radiology, Wallace Memorial Baptist since May 1992. The ACR dictionary files consisted of 11 files, one for the organ code and the others for the pathology code. The organ code was obtained by typing organ name or code number itself among the upper and lower level codes of the selected one that were simultaneous displayed on the screen. According to the first number of the selected organ code, the corresponding pathology code file was chosen automatically. By the similar fashion of organ code selection, the proper pathologic dode was obtained. An example of obtained ACR code is '131.3661'. This procedure was reproducible regardless of the number of fields of data. Because this program was written in 'User's Defined Function' from, decoding of the stored ACR code was achieved by this same program and incorporation of this program into program in to another data processing was possible. This program had merits of simple operation, accurate and detail coding, and easy adjustment for another program. Therefore, this program can be used for automation of routine work in the department of radiology

  18. Germ Cell Tumor Located in the Midline of the Anterior Neck

    OpenAIRE

    Tatyana PIRDOPSKA; Ivan TERZIEV; Sv. HRISTOVA; W. MLADENOVSKY; R. PETKOV

    2011-01-01

    Primary germ cell tumors involving midline of the anterior neck are extremely rare. Here we report a 68-year-old male who was operated due to a mass lesion in the anterior neck with infiltration of the isthmus of the thyroid gland. Histopathological examination revealed a germ cell tumor with extragonadal localization in the anterior neck infiltrating the isthmus of the thyroid gland.

  19. Prevention of airborne contamination and cross-contamination in germ-free mice by laminar flow

    NARCIS (Netherlands)

    Waaij, D. van der; Andres, A.H.

    1971-01-01

    The efficacy of horizontal and vertical laminar flow units (equipped with high-efficiency air filters) in the prevention of cross-contamination between cages and of contamination from outside has been demonstrated. With germ-free mice and using germ-free standard techniques for sterilization and for

  20. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling

    NARCIS (Netherlands)

    Hu, Yueh-Chiang; Nicholls, Peter K; Soh, Y Q Shirleen; Daniele, Joseph R; Junker, Jan Philipp; van Oudenaarden, Alexander|info:eu-repo/dai/nl/166129275; Page, David C

    2015-01-01

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell

  1. The role of germ cell loss during primordial follicle assembly: a review of current advances.

    Science.gov (United States)

    Sun, Yuan-Chao; Sun, Xiao-Feng; Dyce, Paul W; Shen, Wei; Chen, Hong

    2017-01-01

    In most female mammals, early germline development begins with the appearance of primordial germ cells (PGCs), and develops to form mature oocytes following several vital processes. It remains well accepted that significant germ cell apoptosis and oocyte loss takes place around the time of birth. The transition of the ovarian environment from fetal to neonatal, coincides with the loss of germ cells and the timing of follicle formation. All told it is common to lose approximately two thirds of germ cells during this transition period. The current consensus is that germ cell loss can be attributed, at least in part, to programmed cell death (PCD). Recently, autophagy has been implicated as playing a part in germ cell loss during the time of parturition. In this review, we discuss the major opinions and mechanisms of mammalian ovarian PCD during the process of germ cell loss. We also pay close attention to the function of autophagy in germ cell loss, and speculate that autophagy may also serve as a critical and necessary process during the establishment of primordial follicle pool.

  2. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling

    NARCIS (Netherlands)

    Hu, Yueh-Chiang; Nicholls, Peter K; Soh, Y Q Shirleen; Daniele, Joseph R; Junker, Jan Philipp; van Oudenaarden, Alexander; Page, David C

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell

  3. Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)—Health Professional Version

    Science.gov (United States)

    CNS germ cell tumors can be diagnosed and classified based on histology, tumor markers, or a combination of both. Get detailed information about newly diagnosed and recurrent childhood CNS germ cell tumors including molecular features and clinical features, diagnostic and staging evaluation, and treatment in this summary for clinicians.

  4. Recent advances in understanding the etiology and pathogenesis of pediatric germ cell tumors

    DEFF Research Database (Denmark)

    Mosbech, Christiane Hammershaimb; Rechnitzer, Catherine; Brok, Jesper S

    2014-01-01

    transcription factors OCT-3/4, NANOG, and AP-2γ in germinomas/seminomas/dysgerminomas is consistent with retaining a germ cell phenotype. Teratomas, in contrast, develop through a pathway of aberrant somatic differentiation of immature germ cells, and the yolk sac tumors and choriocarcinomas result from...

  5. Analysis of SOX2 expression in developing human testis and germ cell neoplasia

    DEFF Research Database (Denmark)

    Sonne, Si Brask; Perrett, Rebecca M.; Nielsen, John Erik

    2010-01-01

    The transcriptional regulators of pluripotency, POU5F1 (OCT4), NANOG and SOX2, are highly expressed in embryonal carcinoma (EC). In contrast to OCT4 and NANOG, SOX2 has not been demonstrated in the early human germ cell lineage or carcinoma in situ (CIS), the precursor for testicular germ cell...

  6. Examination for intratubular germ cell neoplasia at operation for undescended testis in boys

    DEFF Research Database (Denmark)

    Cortes, Dina; Thorup, Jørgen Mogens; Frisch, M

    1994-01-01

    A total of 843 consecutive boys (median age 12.7 years) who had undergone testicular biopsy at operation for undescended testis was followed into adulthood (median age 25.2 years) to examine for testicular germ cell neoplasia. Five cases of testicular germ cell neoplasia were identified, including...

  7. Dafachronic acid inhibits C. elegans germ cell proliferation in a DAF-12-dependent manner.

    Science.gov (United States)

    Mukherjee, Madhumati; Chaudhari, Snehal N; Balachandran, Riju S; Vagasi, Alexandra S; Kipreos, Edward T

    2017-12-15

    Dafachronic acid (DA) is a bile acid-like steroid hormone that regulates dauer formation, heterochrony, and lifespan in C. elegans. Here, we describe that DA is an inhibitor of C. elegans germ stem cell proliferation in adult hermaphrodites. Using a C. elegans germ cell primary culture system, we show that DA inhibits the proliferation of germ cells in vitro. Exogenous DA reduces the frequency of large tumors in adult tumorous germline mutants and decreases the proliferation of wild-type germ stem cells in adult hermaphrodites. In contrast, DA has no appreciable effect on the proliferation of larval-stage germ cells in wild type. The inhibition of adult germ cell proliferation by DA requires its canonical receptor DAF-12. Blocking DA production by inactivating the cytochrome P450 DAF-9 increases germ cell proliferation in wild-type adult hermaphrodites and the frequency of large tumors in germline tumorous mutants, suggesting that DA inhibits the rate of germ cell proliferation under normal growth conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. CYTOGENETICS, PLOIDY AND DIFFERENTIATION OF HUMAN TESTICULAR, OVARIAN AND EXTRAGONADAL GERM-CELL TUMORS

    NARCIS (Netherlands)

    OOSTERHUIS, JW; CASTEDO, SMMJ; DEJONG, B

    1990-01-01

    Data from cytogenetics of testicular, ovarian and extragonadal germ cell tumours indicate that the group of germ cell tumours for which Skakkebaek proposed the name gonocytoma (seminoma, dysgerminoma and germinoma) is characterized by the presence of isochromosome 12p. The (dysplastic) gonocytes

  9. Fundamentals of convolutional coding

    CERN Document Server

    Johannesson, Rolf

    2015-01-01

    Fundamentals of Convolutional Coding, Second Edition, regarded as a bible of convolutional coding brings you a clear and comprehensive discussion of the basic principles of this field * Two new chapters on low-density parity-check (LDPC) convolutional codes and iterative coding * Viterbi, BCJR, BEAST, list, and sequential decoding of convolutional codes * Distance properties of convolutional codes * Includes a downloadable solutions manual

  10. The role of sex chromosomes in mammalian germ cell differentiation: can the germ cells carrying X and Y chromosomes differentiate into fertile oocytes?

    Directory of Open Access Journals (Sweden)

    Teruko Taketo

    2015-06-01

    Full Text Available The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.

  11. Germ cell regeneration-mediated, enhanced mutagenesis in the ascidian Ciona intestinalis reveals flexible germ cell formation from different somatic cells.

    Science.gov (United States)

    Yoshida, Keita; Hozumi, Akiko; Treen, Nicholas; Sakuma, Tetsushi; Yamamoto, Takashi; Shirae-Kurabayashi, Maki; Sasakura, Yasunori

    2017-03-15

    The ascidian Ciona intestinalis has a high regeneration capacity that enables the regeneration of artificially removed primordial germ cells (PGCs) from somatic cells. We utilized PGC regeneration to establish efficient methods of germ line mutagenesis with transcription activator-like effector nucleases (TALENs). When PGCs were artificially removed from animals in which a TALEN pair was expressed, somatic cells harboring mutations in the target gene were converted into germ cells, this germ cell population exhibited higher mutation rates than animals not subjected to PGC removal. PGC regeneration enables us to use TALEN expression vectors of specific somatic tissues for germ cell mutagenesis. Unexpectedly, cis elements for epidermis, neural tissue and muscle could be used for germ cell mutagenesis, indicating there are multiple sources of regenerated PGCs, suggesting a flexibility of differentiated Ciona somatic cells to regain totipotency. Sperm and eggs of a single hermaphroditic, PGC regenerated animal typically have different mutations, suggesting they arise from different cells. PGCs can be generated from somatic cells even though the maternal PGCs are not removed, suggesting that the PGC regeneration is not solely an artificial event but could have an endogenous function in Ciona. This study provides a technical innovation in the genome-editing methods, including easy establishment of mutant lines. Moreover, this study suggests cellular mechanisms and the potential evolutionary significance of PGC regeneration in Ciona. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. The emerging phenotype of the testicular carcinoma in situ germ cell

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, Ewa; Bartkova, Jirina; Samson, Michel

    2003-01-01

    germ cells to pre-spermatogonia, and later during the pubertal switch from the mitotic to meiotic cell division. The persistent expression of embryonic traits in CIS cells, and the high expression of the cell cycle regulators that are typical of mitotic germ cells support our long-standing hypothesis......This review summarises the existing knowledge on the phenotype of the carcinoma in situ (CIS) cell. CIS is a common pre-invasive precursor of testicular germ cell tumours of adolescents and young adults. These tumours display a variety of histological forms. Classical seminoma proliferates along...... the germ cell lineage, whereas embryonal carcinoma retains embryonic features and readily differentiates into teratomas that resemble various somatic cell lineages. A thorough review of the gene expression in CIS cells in comparison to normal testicular germ cells and overt tumours supports the view...

  13. Endocrine disrupters, microRNAs, and primordial germ cells: a dangerous cocktail.

    Science.gov (United States)

    Brieño-Enríquez, Miguel Angel; Larriba, Eduardo; Del Mazo, Jesús

    2016-09-15

    Endocrine-disrupting chemicals (EDCs) are environmental pollutants that may change the homeostasis of the endocrine system, altering the differentiation of germ cells with consequences for reproduction. In mammals, germ cell differentiation begins with primordial germ cells (PGCs) during embryogenesis. Primordial germ cell development and gametogenesis are genetically regulated processes, in which the posttranscriptional gene regulation could be mediated by small noncoding RNAs (sncRNAs) such as microRNAs (miRNAs). Here, we review the deleterious effects of exposure during fetal life to EDCs mediated by deregulation of ncRNAs, and specifically miRNAs on PGC differentiation. Moreover, the environmental stress induced by exposure to some EDCs during the embryonic window of development could trigger reproductive dysfunctions transgenerationally transmitted by epigenetic mechanisms with the involvement of miRNAs expressed in germ line cells. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Review of Differentiation and Proliferation of Primordial Germ Cells in Culture

    Directory of Open Access Journals (Sweden)

    Zohreh Makoolati

    2011-12-01

    Full Text Available Primordial germ cells (PGCs are highly specialized cell population that arises from the epiblast in vivo. There are three critical steps in the life cycle of these cells: 1-Specification 2-migration and proliferation 3-prenatal and postnatal sex specific development. Specification of germ cells in epiblast occurs due to signals secreted from extraembryonic tissues. Primordial germ cells are required for continuation and development of the species. Thus, differentiation and purification of these cells from different cell sources is valuable for research, genetical analysis of germ cell development, epigenetic eveluation and infertility treatment. The most important part in the germ cell differentiation includes; optimum media selection, distinguishing and purification of differentiated cell. Several studies about in vitro PGC differentiation have been reported. In order to distinguish PGCs in vitro, specific markers which are expressed in these cells are used. Furthermore, functional ability of these cells for production of offspring can be employed for this purpose.

  15. DAZL Expression Explains Origin and Central Formation of Primordial Germ Cells in Chickens.

    Science.gov (United States)

    Lee, Hyung Chul; Choi, Hee Jung; Lee, Hyo Gun; Lim, Jeong Mook; Ono, Tamao; Han, Jae Yong

    2016-01-01

    The timing and biological events associated with germ cell specification in chickens have not been determined yet. In this study, we report the origin of primordial germ cells (PGCs) and germ plasm dynamics through investigation of the expression of the chicken homolog of deleted in azoospermia-like (cDAZL) gene during germ cell specification. Asymmetric localization of germ plasm in the center of oocytes from preovulatory follicle stages leads to PGCs being formed in the center. During cleavage stages, DAZL expression pattern changes from a subcellular localization to a diffuse form before and after zygotic genome activation. Meanwhile, PGCs exhibit transcriptional active status during their specification. In addition, knockdown studies of cDAZL, which result in reduced proliferation, aberrant gene expression profiles, and PGC apoptosis in vitro, suggest its possible roles for PGC formation in chicken. In conclusion, DAZL expression reveals formation and initial positioning of PGCs in chickens.

  16. Pathogenesis of germ cell neoplasia in testicular dysgenesis and disorders of sex development

    DEFF Research Database (Denmark)

    Jørgensen, Anne; Lindhardt Johansen, Marie; Juul, Anders

    2015-01-01

    reproductive problems within the testicular dysgenesis syndrome (TDS), with large overlap between the syndromes. These disorders carry an increased but variable risk of germ cell neoplasia. In this review, we discuss the pathogenesis of germ cell neoplasia associated with gonadal dysgenesis, especially...... in individuals with 46,XY DSD. We summarise knowledge concerning development and sex differentiation of human gonads, with focus on sex-dimorphic steps of germ cell maturation, including meiosis. We also briefly outline the histopathology of germ cell neoplasia in situ (GCNIS) and gonadoblastoma (GDB), which...... are essentially the same precursor lesion but with different morphological structure dependent upon the masculinisation of the somatic niche. To assess the risk of germ cell neoplasia in different types of DSD, we have performed a PubMed search and provide here a synthesis of the evidence from studies published...

  17. The Ter Mutation In The Dead End Gene Causes Germ Cell Loss And Testicular Germ Cell Tumours

    Energy Technology Data Exchange (ETDEWEB)

    Youngren, Kirsten K.; Coveney, Douglas; Peng, Xiaoning; Bhattacharya, Chitralekha; Schmidt, Laura S.; Nickerson, Michael L.; Lamb, Bruce T.; Deng Jian Min; Behringer, Richard R.; Capel, Blanche; Rubin, Edward M.; Nadeau, Joseph H.; Matin, Angabin

    2005-01-01

    In mice, the Ter mutation causes primordial germ cell (PGC) loss in all genetic backgrounds1. Ter is also a potent modifier of spontaneous testicular germ cell tumour (TGCT) susceptibility in the 129 family of inbred strains, and markedly increases TGCT incidence in 129-Ter/Ter males2 4. In 129-Ter/Ter mice, some of the remaining PGCs transform into undifferentiated pluripotent embryonal carcinoma cells2 6, and after birth differentiate into various cells and tissues that compose TGCTs. Here, we report the positional cloning of Ter, revealing a point mutation that introduces a termination codon in the mouse orthologue (Dnd1) of the zebrafish dead end (dnd) gene. PGC deficiency is corrected both with bacterial artificial chromosomes that contain Dnd1 and with a Dnd1-encoding transgene. Dnd1 is expressed in fetal gonads during the critical period when TGCTs originate. DND1 has an RNA recognition motif and is most similar to the apobec complementation factor, a component of the cytidine t o uridine RNA-editing complex. These results suggest that Ter may adversely affect essential aspects of RNA biology during PGC development. DND1 is the first protein known to have an RNA recognition motif directly implicated as a heritable cause of spontaneous tumorigenesis. TGCT development in the 129-Ter mouse strain models paediatric TGCT in humans. This work will have important implications for our understanding of the genetic control of TGCT pathogenesis and PGC biology.

  18. From Young Children's Ideas about Germs to Ideas Shaping a Learning Environment

    Science.gov (United States)

    Ergazaki, Marida; Saltapida, Konstantina; Zogza, Vassiliki

    2010-11-01

    This paper is concerned with highlighting young children’s ideas about the nature, location and appearance of germs, as well as their reasoning strands about germs’ ontological category and biological functions. Moreover, it is concerned with exploring how all these could be taken into account for shaping a potentially fruitful learning environment. Conducting individual, semi-structured interviews with 35 preschoolers (age 4.5-5.5) of public kindergartens in the broader area of Patras, we attempted to trace their ideas about what germs are, where they may be found, whether they are good or bad and living or non-living and how they might look like in a drawing. Moreover, children were required to attribute a series of biological functions to dogs, chairs and germs, and finally to create a story with germs holding a key-role. The analysis of our qualitative data within the “NVivo” software showed that the informants make a strong association of germs with health and hygiene issues, locate germs mostly in our body and the external environment, are not familiar with the ‘good germs’-idea, and draw germs as ‘human-like’, ‘animal-like’ or ‘abstract’ entities. Moreover, they have significant difficulties not only in employing biological functions as criteria for classifying germs in the category of ‘living’, but also in just attributing such functions to germs using a warrant. Finally, the shift from our findings to a 3-part learning environment aiming at supporting preschoolers in refining their initial conceptualization of germs is thoroughly discussed in the paper.

  19. Removal and isolation of germ-rich fractions from hull-less barley using a fitzpatrick comminuting mill

    Science.gov (United States)

    A process was developed to produce a germ-enriched fraction from hull-less barley using a Fitzpatrick Comminuting Mill followed by sieving. Hulled and hull-less barleys contain 1.5-2.5% oil and, like wheat kernels which contain wheat germ oil, much of the oil in barley kernels is in the germ fracti...

  20. Evaluation of corn germ from ethanol production as an alternative fat source in dairy cow diets.

    Science.gov (United States)

    Abdelqader, M M; Hippen, A R; Kalscheur, K F; Schingoethe, D J; Karges, K; Gibson, M L

    2009-03-01

    Sixteen multiparous cows (12 Holstein and 4 Brown Swiss, 132 +/- 20 d in milk) were used in a replicated 4 x 4 Latin square design with 4-wk periods to determine the effects of feeding corn germ on dairy cow performance. Diets were formulated with increasing concentrations of corn germ (Dakota Germ, Poet Nutrition, Sioux Falls, SD) at 0, 7, 14, and 21% of the diet dry matter (DM). All diets had a 55:45 forage to concentrate ratio, where forage was 55% corn silage and 45% alfalfa hay. Dietary fat increased from 4.8% in the control diet to 8.2% at the greatest inclusion level of corn germ. The addition of corn germ resulted in a quadratic response in DM intake with numerically greater intake at 14% of diet DM. Feeding corn germ at 7 and 14% of diet DM increased milk yield and energy-corrected milk as well as fat percentage and yield. Milk protein yield tended to decrease as the concentration of corn germ increased in the diet. Dietary treatments had no effect on feed efficiency, which averaged 1.40 kg of energy-corrected milk/kg of DMI. Increasing the dietary concentration of corn germ resulted in a linear increase in milk fat concentrations of monounsaturated and polyunsaturated fatty acids at the expense of saturated fatty acids. Milk fat concentration and yield of cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid were increased with increased dietary concentrations of corn germ. Although milk fat concentrations of both total trans-18:1 and cis-18:1 fatty acids increased linearly, a marked numeric increase in the concentration of trans-10 C18:1 was observed in milk from cows fed the 21% corn germ diet. A similar response was observed in plasma concentration of trans-10 C18:1. Feeding increasing concentrations of corn germ had no effect on plasma concentrations of glucose, triglyceride, or beta-hydroxybutyrate; however, the concentration of nonesterified fatty acids increased linearly, with plasma cholesterol concentration demonstrating a similar trend

  1. Testicular germ cell tumours and parental occupational exposure to pesticides

    DEFF Research Database (Denmark)

    Le Cornet, Charlotte; Fervers, Béatrice; Oksbjerg Dalton, Susanne

    2015-01-01

    controls per case were randomly selected from the general national populations, matched on year of birth. Information on parental occupation was collected through censuses or Pension Fund information and converted into a pesticide exposure index based on the Finnish National Job-Exposure Matrix. RESULTS......OBJECTIVES: A potential impact of exposure to endocrine disruptors, including pesticides, during intrauterine life, has been hypothesised in testicular germ cell tumour (TGCT) aetiology, but exposure assessment is challenging. This large-scale registry-based case-control study aimed to investigate......: A total of 9569 cases and 32 028 controls were included. No overall associations were found for either maternal or paternal exposures and TGCT risk in their sons, with ORs of 0.83 (95% CI 0.56 to 1.23) and of 1.03 (0.92 to 1.14), respectively. Country-specific estimates and stratification by birth cohorts...

  2. Testicular germ cell tumors: Molecular genetic and clinicomorphological aspects

    Directory of Open Access Journals (Sweden)

    M. V. Nemtsova

    2015-03-01

    Full Text Available Testicular tumors are the most common form of solid cancer in young men. According to the 2004 WHO classification, testicular germ cell tumors (TGCT may present with different histological types. Embryonic cells of varying grade may be a source of TGCT and the occurrence of this type of tumors is directly related to the formation of a pool of male sex cells and gametogenesis. The paper gives information on mo- lecular stages for the process of formation of male sex cells in health, as well as ways of their impairments leading to TGCT. An investigation of the profiles of gene expression and the spectrum of molecular damages revealed genes responsible for a predisposition to the sporadic and hereditary forms of TGCT. The paper presents the current molecular genetic and clinicomorphological characteristics of TGCT. 

  3. Primordial germ cell specification from embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Wei Wei

    Full Text Available BACKGROUND: Primordial germ cell (PGC specification is the first crucial step in germ line development. However, owing to significant challenges regarding the in vivo system, such as the complex cellular environment and potential problems with embryo manipulation, it is desirable to generate embryonic stem (ES cells that are capable of overcoming these aforementioned limitations in order to provide a potential in vitro model to recapitulate the developmental processes in vivo. METHODOLOGY AND PRINCIPAL FINDINGS: Here, we studied the detailed process of PGC specification from stella-GFP ES cells. We first observed the heterogeneous expression of stella in ES cells. However, neither Stella-positive ES cells nor Stella-negative ES cells shared a similar gene expression pattern with either PGCs or PGC precursors. Second, we derived PGCs from ES cells using two differentiation methods, namely the attachment culture technique and the embryoid body (EB method. Compared with PGCs derived via the attachment culture technique, PGCs derived via the EB method that had undergone the sequential erasure of Peg3 followed by Igf2r resulted in a cell line in which the expression dynamics of T, Fgf8 and Sox17, in addition to the expression of the epiblast markers, were more similar to the in vivo expression, thus demonstrating that the process of PGC derivation was more faithfully recapitulated using the EB method. Furthermore, we developed an in vitro model of PGC specification in a completely chemically defined medium (CDM that indicated that BMP4 and Wnt3a promoted PGC derivation, whereas BMP8b and activinA had no observable effect on PGC derivation. CONCLUSIONS AND SIGNIFICANCE: The in vitro model we have established can recapitulate the developmental processes in vivo and provides new insights into the mechanism of PGC specification.

  4. The fog-3 gene and regulation of cell fate in the germ line of Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, R.; Kimble, J. [Univ. of Wisconsin, Madison, WI (United States)

    1995-02-01

    In the nematode Caenorhabditis elegans, germ cells normally adopt one of three fates: mitosis, spermatogenesis or oogenesis. We have identified and characterized the gene fog-3, which is required for germ cells to differentiate as sperm rather than as oocytes. Analysis of double mutants suggests that fog-3 is absolutely required for spermatogenesis and acts at the end of the regulatory hierarchy controlling sex determination for the germ line. By contrast, mutations in fog-3 do not alter the sexual identity of other tissues. We also have characterized the null phenotype of fog-1, another gene required for spermatogenesis; we demonstrate that it too controls the sexual identity of germ cells but not of other tissues. Finally, we have studied the same interaction of these two fog genes with gld-1, a gene required for germ cells to undergo oogenesis rather than mitosis. On the basis of these results, we propose that germ-cell fate might be controlled by a set of inhibitory interactions among genes that specify one of three fates: mitosis, spermatogenesis or oogenesis. Such a regulatory network would link the adoption of one germ-cell fate to the suppression of the other two. 68 refs., 7 figs., 6 tabs.

  5. NUP50 is necessary for the survival of primordial germ cells in mouse embryos.

    Science.gov (United States)

    Park, Eunsook; Lee, Bobae; Clurman, Bruce E; Lee, Keesook

    2016-01-01

    Nucleoporin 50 kDa (NUP50), a component of the nuclear pore complex, is highly expressed in male germ cells, but its role in germ cells is largely unknown. In this study, we analyzed the expression and function of NUP50 during the embryonic development of germ cells using NUP50-deficient mice. NUP50 was expressed in germ cells of both sexes at embryonic day 15.5 (E15.5), E13.5, and E12.5. In addition, NUP50 expression was also detected in primordial germ cells (PGCs) migrating into the genital ridges at E9.5. The gonads of Nup50-/- embryos of both sexes contained few PGCs at both E11.5 and E12.5 and no developing germ cells at E15.5. The migratory PGCs in Nup50-/- embryos at E9.5 showed increased apoptosis but a normal rate of proliferation, resulting in the progressive loss of germ cells at later stages. Taken together, these results suggest that NUP50 plays an essential role in the survival of PGCs during embryonic development. © 2016 Society for Reproduction and Fertility.

  6. Drosophila germ granules are structured and contain homotypic mRNA clusters

    Science.gov (United States)

    Trcek, Tatjana; Grosch, Markus; York, Andrew; Shroff, Hari; Lionnet, Timothée; Lehmann, Ruth

    2015-01-01

    Germ granules, specialized ribonucleoprotein particles, are a hallmark of all germ cells. In Drosophila, an estimated 200 mRNAs are enriched in the germ plasm, and some of these have important, often conserved roles in germ cell formation, specification, survival and migration. How mRNAs are spatially distributed within a germ granule and whether their position defines functional properties is unclear. Here we show, using single-molecule FISH and structured illumination microscopy, a super-resolution approach, that mRNAs are spatially organized within the granule whereas core germ plasm proteins are distributed evenly throughout the granule. Multiple copies of single mRNAs organize into ‘homotypic clusters' that occupy defined positions within the center or periphery of the granule. This organization, which is maintained during embryogenesis and independent of the translational or degradation activity of mRNAs, reveals new regulatory mechanisms for germ plasm mRNAs that may be applicable to other mRNA granules. PMID:26242323

  7. Germ cell tumor of ovary with plenty of sarcoid like granulomas: A diagnosis on fine needle aspiration cytology

    Directory of Open Access Journals (Sweden)

    Reshma S Davanageri

    2012-01-01

    Full Text Available Germ cell tumors of ovary with elements of two or more subtypes are relatively uncommon. Sarcoid-like granulomas are seen in rare association with dysgerminomas, a subgroup of germ cell tumors of ovary, which are again less common. Fine-needle aspiration cytology (FNAC of the gonadal germ cell tumor, though not performed frequently, is of help when a gonadal mass does not require resection as in lymphoma which can be treated by chemotherapy. FNAC helps to diagnose this tumor and to rule out other lesions, including germ cell tumors. It is also an effective, rapid and reliable procedure for the diagnosis of germ cell tumors.

  8. Model Children's Code.

    Science.gov (United States)

    New Mexico Univ., Albuquerque. American Indian Law Center.

    The Model Children's Code was developed to provide a legally correct model code that American Indian tribes can use to enact children's codes that fulfill their legal, cultural and economic needs. Code sections cover the court system, jurisdiction, juvenile offender procedures, minor-in-need-of-care, and termination. Almost every Code section is…

  9. Affine Grassmann codes

    DEFF Research Database (Denmark)

    Høholdt, Tom; Beelen, Peter; Ghorpade, Sudhir Ramakant

    2010-01-01

    We consider a new class of linear codes, called affine Grassmann codes. These can be viewed as a variant of generalized Reed-Muller codes and are closely related to Grassmann codes.We determine the length, dimension, and the minimum distance of any affine Grassmann code. Moreover, we show that af...

  10. Complete androgen insensitivity syndrome: factors influencing gonadal histology including germ cell pathology.

    Science.gov (United States)

    Kaprova-Pleskacova, Jana; Stoop, Hans; Brüggenwirth, Hennie; Cools, Martine; Wolffenbuttel, Katja P; Drop, Stenvert L S; Snajderova, Marta; Lebl, Jan; Oosterhuis, J Wolter; Looijenga, Leendert H J

    2014-05-01

    Patients with complete androgen insensitivity syndrome are at an increased risk for the development of gonadal germ cell cancer. Residual androgen receptor (AR) activity and abnormal gonadal location may influence the survival of atypical germ cells and the development of other histopathological features. To assess this, we evaluated 37 gonads from 19 patients with complete androgen insensitivity (ranging in age from 3 months to 18 years). Histological abnormalities were examined using hematoxylin and eosin-stained sections and sections stained for POU5F1 and KITLG, markers of early changes in germ cells at risk for malignant transformation. Hamartomatous nodules (HNs), Leydig cell hyperplasia (LCH), decreased germ cells, tubular atrophy and stromal fibrosis were more pronounced as age increased (Peffect of inguinal versus abdominal position of the gonads was difficult to assess because inguinal gonads were present primarily in the youngest individuals. In conclusion, many histological changes occur increasingly with age. Expected residual AR activity contributes to better survival of the general germ cell population in (post)pubertal age; however, it did not seem to have an important role in the survival of the germ cells at risk for malignant transformation (defined by POU5F1 positivity and KITLG overexpression) in complete androgen insensitivity. Comparison of the high percentage of patients in our study that were carrying germ cells with delayed maturation or pre-intratubular germ cell neoplasia with previously reported cumulative risk of tumor development in adult patients indicates that not all such precursor lesions in complete androgen insensitivity will progress to invasive germ cell cancer.

  11. Regulatory elements and transcriptional control of chickenvasahomologue (CVH) promoter in chicken primordial germ cells.

    Science.gov (United States)

    Jin, So Dam; Lee, Bo Ram; Hwang, Young Sun; Lee, Hong Jo; Rim, Jong Seop; Han, Jae Yong

    2017-01-01

    Primordial germ cells (PGCs), the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to somatic cells. They express germ cell-specific RNA binding proteins (RBPs) by modulating tissue-specific cis - and trans -regulatory elements. Studies on gene structures of chicken vasa homologue ( CVH ), a chicken RNA binding protein, involved in temporal and spatial regulation are thus important not only for understanding the molecular mechanisms that regulate germ cell fate, but also for practical applications of primordial germ cells. However, very limited studies are available on regulatory elements that control germ cell-specific expression in chicken. Therefore, we investigated the intricate regulatory mechanism(s) that governs transcriptional control of CVH . We constructed green fluorescence protein (GFP) or luciferase reporter vectors containing the various 5' flanking regions of CVH gene. From the 5' deletion and fragmented assays in chicken PGCs, we have identified a CVH promoter that locates at -316 to +275 base pair fragment with the highest luciferase activity. Additionally, we confirmed for the first time that the 5' untranslated region (UTR) containing intron 1 is required for promoter activity of the CVH gene in chicken PGCs. Furthermore, using a transcription factor binding prediction, transcriptome analysis and siRNA-mediated knockdown, we have identified that a set of transcription factors play a role in the PGC-specific CVH gene expression. These results demonstrate that cis -elements and transcription factors localizing in the 5' flanking region including the 5' UTR and an intron are important for transcriptional regulation of the CVH gene in chicken PGCs. Finally, this information will contribute to research studies in areas of reproductive biology, constructing of germ cell-specific synthetic promoter for tracing primordial germ cells as well

  12. EKSTRAKSI DAN ANALISIS FITOSTEROL LEMBAGA GANDUM [Extraction and analysis of Phytosterol from wheat germ (Triticum sp.

    Directory of Open Access Journals (Sweden)

    Latifah K Darusman3

    2005-04-01

    Full Text Available Phytosterol may reduce the absorption of cholesterol, and used for preventing atherosclerosis. It is limited in soybean, but potentially abundant in wheat germ. Research on the utilization of wheat germ sterol had not been reported so far. Many aspects of germ sterol extraction from wheat germ and its characteristics were still unknown. In this research, the best extraction method, kinds and content of phytosterol from wheat germ were investigated.This research consisted of two steps: (1 extraction of phytosterol directly form whole germ and ground germ using hexane, and indirect extraction through germ oil using hexane and mixed solvent of hexane and ethanol, and direct extraction from ground germ using ethanol; (2 analysis of the type and content of phytosterol in the crude extract through the following steps: preparation of crude extract, fractionation, and analysis.Results showed that indirect extraction through germ oil was considered as the best method which yielded 1.37% of phytosterol. The highest yield was obtained when extracted using a mixed solvent of hexane – ethanol 82:18. However, the odor of ethanol and hexane (gasoline like odor was still detected. The solvent’s ratio of hexane to ethanol at 1:2 resulted better odor of the extract. Extraction of sterol using ethanol yielded 18.39% of sterol when the ratio of germ to ethanol at 1:10 (w/v was applied.Results of quantitative analysis on the main component of crude extract of wheat germ sterol showed that the total content of sterol extracted with mixed solvent was higher than those extracted with ethanol. The ratio of hexane to ethanol at 1:1 (v/v gave higher content of total sterol, stigmasterol and campesterol, whereas higher content of -sitosterol was produced at the solvent’s ratio of hexane to ethanol at 1:2 (v/v.

  13. Severe acute tumor lysis syndrome in patients with germ-cell tumors

    Directory of Open Access Journals (Sweden)

    Guilherme Alvarenga Feres

    2008-01-01

    Full Text Available Germ-cell tumors are a high-proliferative type of cancer that may evolve to significant bulky disease. Tumor lysis syndrome is rarely reported in this setting. The reports of three patients with germ-cell tumors who developed severe acute tumor lysis syndrome following the start of their anticancer therapy are presented. All patients developed renal dysfunction and multiorgan failure. Patients with extensive germ-cell tumors should be kept on close clinical and laboratory monitoring. Physicians should be aware of this uncommon but severe complication and consider early admission to the intensive care unit for the institution of measures to prevent acute renal failure.

  14. Fat absorption in germ-free and conventional rats artificially deprived of bile secretion

    OpenAIRE

    Demarne, Y.; Corring, T.; Pihet, A.; Sacquet, E.

    1982-01-01

    Bile duct ligation was performed in germ-free and conventional rats in order to study the effects of bile deprivation on the absorption of dietary lipids and the excretion of faecal lipids in the presence or the absence of gastrointestinal flora. The main consequence of bile duct ligation in conventional rats was decrease of about 50% in the apparent absorption of dietary lipids (peanut oil). In germ-free rats, absorption decreased by only about 25%.In conventional as well as in germ-free con...

  15. Erythropoietin may reduce the risk of germ cell loss in boys with cryptorchidism

    DEFF Research Database (Denmark)

    Cortes, Dina; Visfeldt, J; Thorup, J M

    2001-01-01

    that hormonal treatment with human chorionic gonadotropin or gonadotropin releasing hormone analogue may harm the germ cells in cryptorchidism. The aim of the study is to demonstrate that additional hormonal therapy with erythropoietin has a positive effect on the number of germ cells....... of infertility. In order to increase the number of germ cells, and thereby the fertility potential, additional hormonal therapy has been attempted before surgery. In a study, small doses of the gonadotropin-releasing hormone analogue buserelin before orchiopexy caused higher values. Others have found...

  16. Regulation of fetal male germ cell development by members of the TGFβ superfamily

    Directory of Open Access Journals (Sweden)

    Cassy Spiller

    2017-10-01

    Full Text Available There is now substantial evidence that members of the transforming growth factor-β (TGFβ family regulate germ cell development in the mouse fetal testis. Correct development of germ cells during fetal life is critical for establishment of effective spermatogenesis and for avoiding the formation of testicular germ cell cancer in later life. Here we consider the evidence for involvement of various TGFβ family members, attempt to reconcile discrepancies and clarify what we believe to be the likely in vivo roles of these factors.

  17. Regulation of fetal male germ cell development by members of the TGFβ superfamily.

    Science.gov (United States)

    Spiller, Cassy; Burnet, Guillaume; Bowles, Josephine

    2017-10-01

    There is now substantial evidence that members of the transforming growth factor-β (TGFβ family) regulate germ cell development in the mouse fetal testis. Correct development of germ cells during fetal life is critical for establishment of effective spermatogenesis and for avoiding the formation of testicular germ cell cancer in later life. Here we consider the evidence for involvement of various TGFβ family members, attempt to reconcile discrepancies and clarify what we believe to be the likely in vivo roles of these factors. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  18. Defatted wheat germ application: Influence on cookies' properties with regard to its particle size and dough moisture content.

    Science.gov (United States)

    Petrović, Jovana; Rakić, Dušan; Fišteš, Aleksandar; Pajin, Biljana; Lončarević, Ivana; Tomović, Vladimir; Zarić, Danica

    2017-10-01

    The introduction of agro-food industry by-products rich in bioactive compounds represents major challenge in food industry sector. The influence of wheat germ particle size (cookies was investigated using the Box-Behnken experimental design. The substitution of wheat flour with wheat germ increased the protein, fat, mineral, and fiber content of the cookies. The particle size of wheat germ affected the textural properties of cookies. As the particle size of wheat germ increased, the hardness of cookies decreased. The color of the cookie was most influenced by the interaction of dough moisture content and wheat germ particle size. Wheat germ level up to 15% had no significant effect on the sensory characteristics of cookies. A suitable combination of defatted wheat germ level, its particle size, and dough moisture content can improve the nutritional value of cookies, without causing a negative effect on the cookies' sensory characteristics.

  19. Generalized concatenated quantum codes

    International Nuclear Information System (INIS)

    Grassl, Markus; Shor, Peter; Smith, Graeme; Smolin, John; Zeng Bei

    2009-01-01

    We discuss the concept of generalized concatenated quantum codes. This generalized concatenation method provides a systematical way for constructing good quantum codes, both stabilizer codes and nonadditive codes. Using this method, we construct families of single-error-correcting nonadditive quantum codes, in both binary and nonbinary cases, which not only outperform any stabilizer codes for finite block length but also asymptotically meet the quantum Hamming bound for large block length.

  20. Rateless feedback codes

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Koike-Akino, Toshiaki; Orlik, Philip

    2012-01-01

    This paper proposes a concept called rateless feedback coding. We redesign the existing LT and Raptor codes, by introducing new degree distributions for the case when a few feedback opportunities are available. We show that incorporating feedback to LT codes can significantly decrease both...... the coding overhead and the encoding/decoding complexity. Moreover, we show that, at the price of a slight increase in the coding overhead, linear complexity is achieved with Raptor feedback coding....

  1. Coding for dummies

    CERN Document Server

    Abraham, Nikhil

    2015-01-01

    Hands-on exercises help you learn to code like a pro No coding experience is required for Coding For Dummies,your one-stop guide to building a foundation of knowledge inwriting computer code for web, application, and softwaredevelopment. It doesn't matter if you've dabbled in coding or neverwritten a line of code, this book guides you through the basics.Using foundational web development languages like HTML, CSS, andJavaScript, it explains in plain English how coding works and whyit's needed. Online exercises developed by Codecademy, a leading online codetraining site, help hone coding skill

  2. Advanced video coding systems

    CERN Document Server

    Gao, Wen

    2015-01-01

    This comprehensive and accessible text/reference presents an overview of the state of the art in video coding technology. Specifically, the book introduces the tools of the AVS2 standard, describing how AVS2 can help to achieve a significant improvement in coding efficiency for future video networks and applications by incorporating smarter coding tools such as scene video coding. Topics and features: introduces the basic concepts in video coding, and presents a short history of video coding technology and standards; reviews the coding framework, main coding tools, and syntax structure of AV

  3. In Vitro Effect of Local Anesthetics on Candida albicans Germ Tube Formation

    Directory of Open Access Journals (Sweden)

    Acácio Rodrigues

    1994-01-01

    Full Text Available Objective: This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation by Candida albicans isolates from cases of clinical vaginal candidiasis.

  4. The uranyl influence on a mutation process in germ and somatic cells of mice

    International Nuclear Information System (INIS)

    Kostrova, L.N.; Mosseh, I.B.; Molofej, V.P.

    2008-01-01

    The mutagenic effect of uranyl was revealed by the chromosome rearrangement test in germ and somatic cells of mice. The effect value depended on duration of substance administration into organism. (authors)

  5. Xenopus Vasa Homolog XVLG1 is Essential for Migration and Survival of Primordial Germ Cells.

    Science.gov (United States)

    Shimaoka, Kazumi; Mukumoto, Yoshiko; Tanigawa, Yoko; Komiya, Tohru

    2017-04-01

    Xenopus vasa-like gene 1 (XVLG1), a DEAD-Box Helicase 4 (DDX4) gene identified as a vertebrate vasa homologue, is required for the formation of primordial germ cells (PGCs). However, it remains to be clarified when and how XVLG1 functions in the formation of the germ cells. To gain a better understanding of the molecular mechanisms underlying XVLG1 during PGC development, we injected XVLG1 morpholino oligos into germ-plasm containing blastomeres of 32-cell stage of Xenopus embryos, and traced cell fates of the injected blastomere-derived PGCs. As a result of this procedure, migration of the PGCs was impaired and the number of PGCs derived from the blastomeres was significantly decreased. In addition, TUNEL staining in combination with in situ hybridization revealed that the loss of PGCs peaked at stage 27 was caused by apoptosis. This data strongly suggests an essential role for XVLG1 in migration and survival of the germ cells.

  6. Conservation of Migration and Differentiation Circuits in Primordial Germ Cells Between Avian Species

    Science.gov (United States)

    PARK, Tae Sub; HAN, Jae Yong

    2013-01-01

    Abstract Germ cell differentiation in reverse-sexed reproductive organs and interspecies germ line chimeras provides insight into the mechanism of germ cell development and represents a useful tool for conservation of endangered birds. We investigated the migration and survival capacity of male chicken primordial germ cells (PGCs) in female chicken embryos and in quail and Korean ring-necked pheasant embryos of both sexes. Interestingly, the PGCs were successfully reintroduced in all cases. Furthermore, the cells survived in the recipient gonads until hatching regardless of sex and species of the recipient. In the case of male recipient chickens, PGC-derived offspring were produced. However, the reverse-sexed female chickens, quails and pheasants of both sexes did not generate any male donor PGC-derived progeny. These results suggest that migration and survival circuits in chicken PGCs are conserved in both sexes and between avian species during embryonic development. PMID:23386102

  7. The Vertebrate Protein Dead End Maintains Primordial Germ Cell Fate by Inhibiting Somatic Differentiation.

    Science.gov (United States)

    Gross-Thebing, Theresa; Yigit, Sargon; Pfeiffer, Jana; Reichman-Fried, Michal; Bandemer, Jan; Ruckert, Christian; Rathmer, Christin; Goudarzi, Mehdi; Stehling, Martin; Tarbashevich, Katsiaryna; Seggewiss, Jochen; Raz, Erez

    2017-12-18

    Maintaining cell fate relies on robust mechanisms that prevent the differentiation of specified cells into other cell types. This is especially critical during embryogenesis, when extensive cell proliferation, patterning, and migration events take place. Here we show that vertebrate primordial germ cells (PGCs) are protected from reprogramming into other cell types by the RNA-binding protein Dead end (Dnd). PGCs knocked down for Dnd lose their characteristic morphology and adopt various somatic cell fates. Concomitantly, they gain a gene expression profile reflecting differentiation into cells of different germ layers, in a process that we could direct by expression of specific cell-fate determinants. Importantly, we visualized these events within live zebrafish embryos, which provide temporal information regarding cell reprogramming. Our results shed light on the mechanisms controlling germ cell fate maintenance and are relevant for the formation of teratoma, a tumor class composed of cells from more than one germ layer. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. DEFINITION OF A NEW ENTITY OF MALIGNANT EXTRAGONADAL GERM-CELL TUMORS

    NARCIS (Netherlands)

    VANECHTEN, J; DEJONG, B; SINKE, RJ; WEGHUIS, DO; SLEIJFER, DT; OOSTERHUIS, JW

    Two malignant extragonadal germ cell tumors are reponed, histologically classified as immature teratomas, having pseudodiploid karyotypes with complex structural rearrangements but lacking isochromosome 12p or other rearrangements involving 12p. The absence of 12p material in structural

  9. Expression of immunohistochemical markers for testicular carcinoma in situ by normal human fetal germ cells

    DEFF Research Database (Denmark)

    Jørgensen, N; Rajpert-De Meyts, E; Graem, N

    1995-01-01

    study. EXPERIMENTAL DESIGN: Normal human germ cells from 10 first-trimester fetuses and 76 second- and third-trimester testes were investigated for the immunohistochemical expression of the markers of testicular carcinoma in situ. The panel of markers included in the study consisted of placental......-like alkaline phosphatase, the protooncogene c-kit protein product, and the antigens for the monoclonal antibodies TRA-1-60 and M2A. The relative numbers of fetal germ cells that demonstrated positive reaction with the markers were calculated. RESULTS: The vast majority of the germ cells (75-100%) in the first......-trimester gonads were positive for placental-like alkaline phosphatase, TRA-1-60, and M2A. The c-kit protein was detected in three out of the ten first-trimester gonads. The relative number of germ cells positive for all the markers studied declined rapidly during the first part of the second trimester...

  10. Pathogenesis of Testicular Germ Cell Tumors from a Developmental Point of View

    NARCIS (Netherlands)

    K. Biermann (Katharina)

    2010-01-01

    textabstractCurrent classification systems of human germ cell tumors (GCTs) are based on histological composition. In the group of nonseminomas, different variants of teratoma (somatic differentiation), yolk sac tumor and choriocarcinoma (extra-embryonic differentiation), are recognized, as well

  11. CDC Vital Signs: Making Health Care Safer -- Stop Infections from Lethal CRE Germs Now

    Science.gov (United States)

    ... Making Health Care Safer Stop Infections from Lethal CRE Germs Now Recommend on Facebook Tweet Share Compartir ... hospitals had at least one patient with a CRE (carbapenem-resistant Enterobacteriaceae) infection during the first half ...

  12. Sexual functioning after multimodality treatment for disseminated nonseminomatous testicular germ cell tumor

    NARCIS (Netherlands)

    VanBasten, JP; JonkerPool, G; VanDriel, MF; Sleijfer, DT; Droste, JHJ; VandeWiel, HBM; Molenaar, WM; Hoekstra, HJ; Schraffordt Koops, H.

    1997-01-01

    Purpose: We determined sexual functioning after chemotherapy for disseminated nonseminomatous testicular germ cell tumor, and evaluated the impact of resection of post-chemotherapy residual retroperitoneal tumor. Materials and Methods: A total of 155 consecutive patients treated with chemotherapy

  13. Repair and mutation induction in mouse germ cells: a summary and some thoughts

    International Nuclear Information System (INIS)

    Russell, L.B.

    1979-01-01

    The various lines of evidence for repair of premutational damage in mouse germ cells are reviewed with the implications for future experiment planning. Relation between mutagenicity and carcinogenicity are discussed

  14. A genetic perspective of male germ cell tumors.

    Science.gov (United States)

    Murty, V V; Chaganti, R S

    1998-04-01

    Adult human male germ cell tumors (GCTs) arise by transformation of germ cells (GCs). The transformed GCs exhibit pluripotentiality to differentiate into embryonic, extra-embryonic, and somatic tissue types, and are highly sensitive to cisplatin-based chemotherapy. Recent investigations into the genetics of GCTs have advanced methods of diagnosis and provided leads to the understanding of molecular basis of transformation, differentiation, and sensitivity/resistance. Cytogenetic and molecular cytogenetic studies have identified multiplication of 12p, manifested in i(12p) or tandem duplication of 12p, as a unique change in GCTs which serves as a diagnostic marker. Ectopic over-expression of cyclin D2, a gene mapped to 12p, as early as in carcinoma in situ identifies a candidate gene in GC transformation. Genetic alterations identified in the tumor suppressor genes deleted in colorectal cancer, retinoblastoma 1 and non-metastatic protein 23 (NME) in GCT suggest that their inactivation play a key role in transformation or differentiation. A number of regions of chromosomal deletion have been identified including those previously known to be deleted in various tumor types and novel candidate tumor suppressor gene sites such as 12q13, 12q22, and 5p15.1-15.2. Identification and characterization of the genes in these sites will provide important clues in understanding the biology of GCT. The molecular studies have also enumerated several possible differentiation controls such as switching of KIT and mast cell growth factor gene expression in a lineage-associated manner, and loss of certain types of genes such as NME in teratomas that may act in a dominant negative fashion in differentiation. The exquisite sensitivity of these tumors to chemotherapy is reflected in their over-expression of wild-type p53 protein and lack of TP53 mutations. These data indicate that multiple genetic events play a role in distinct pathways in the development of GCT, and further elucidation of

  15. Gonadal germ cell tumors in children and adolescents

    Directory of Open Access Journals (Sweden)

    Giovanni Cecchetto

    2014-01-01

    Full Text Available Pediatric germ cell tumors (GCT are rare tumors: 80% are benign, 20% malignant (2-3% of all malignant pediatric tumors. The gonadal sites (ovary and testis account for 40% of cases. Ovarian GCTs: Represent 30% of GCTs and 70% of neoplastic ovarian masses, being the most common ovarian neoplasms in children and teenagers. Benign and immature forms (teratomas constitute about 80% of all ovarian GCTs, malignant forms represent 20% increasing during adolescence. The most common malignant entity in children is the yolk sac tumors (YST; dysgerminoma is frequent during adolescence and being bilateral in 10% of cases. Presentation is similar in malignant and benign lesions; abdominal pain (70-80% and lower abdominal mass are common symptoms. Evaluation of alpha-fetoprotein (αFP or beta subunit of human chorionic gonadotropin (βHCG is essential to address the nature of the tumors: Their elevation means presence of malignancy. Surgery includes intraoperative staging procedures and requires ovariectomy or ovarosalpingectomy for malignant lesions, but may be conservative in selected benign tumors. Since malignant GCTs are very chemosensitive, primary chemotherapy is recommended in metastatic or locally advanced tumors. Testicular GCT: Represent 10% of pediatric GCT, and about 30% of malignant GCT with two age peaks: Children <3 years may experience mature teratoma and malignant GCTs, represented almost exclusively by YST, while adolescents may also show seminomas or other mixed tumors. The main clinical feature is a painless scrotal mass. Surgery represents the cornerstone of the management of testicular GCTs, with an inguinal approach and a primary high orchidectomy for malignant tumors, while a testis-sparing surgery can be considered for benign lesions. A retroperitoneal lymph node (LN biopsy may be necessary to define the staging when the involvement of retroperitoneal LN is uncertain at imaging investigations. Conclusion: Patients with gonadal

  16. Deletion of genes implicated in protecting the integrity of male germ cells has differential effects on the incidence of DNA breaks and germ cell loss.

    Directory of Open Access Journals (Sweden)

    Catriona Paul

    2007-10-01

    Full Text Available Infertility affects approximately 20% of couples in Europe and in 50% of cases the problem lies with the male partner. The impact of damaged DNA originating in the male germ line on infertility is poorly understood but may increase miscarriage. Mouse models allow us to investigate how deficiencies in DNA repair/damage response pathways impact on formation and function of male germ cells. We have investigated mice with deletions of ERCC1 (excision repair cross-complementing gene 1, MSH2 (MutS homolog 2, involved in mismatch repair pathway, and p53 (tumour suppressor gene implicated in elimination of germ cells with DNA damage.We demonstrate for the first time that depletion of ERCC1 or p53 from germ cells results in an increased incidence of unrepaired DNA breaks in pachytene spermatocytes and increased numbers of caspase-3 positive (apoptotic germ cells. Sertoli cell-only tubules were detected in testes from mice lacking expression of ERCC1 or MSH2 but not p53. The number of sperm recovered from epididymes was significantly reduced in mice lacking testicular ERCC1 and 40% of sperm contained DNA breaks whereas the numbers of sperm were not different to controls in adult Msh2 -/- or p53 -/- mice nor did they have significantly compromised DNA.These data have demonstrated that deletion of Ercc1, Msh2 and p53 can have differential but overlapping affects on germ cell function and sperm production. These findings increase our understanding of the ways in which gene mutations can have an impact on male fertility.

  17. Recovering corn germ enriched in recombinant protein by wet-fractionation.

    Science.gov (United States)

    Paraman, Ilankovan; Fox, Steven R; Aspelund, Matthew T; Glatz, Charles E; Johnson, Lawrence A

    2010-01-01

    Corn wet-fractionation processes (quick-germ fractionation and traditional wet milling) were evaluated as means of recovering fractions rich in recombinant collagen-related proteins that were targeted for expression in the germ (embryo) of transgenic corn. Transgenic corn lines accumulating a recombinant full-length human collagen type-I-alpha-1 (full-length rCIalpha1) or a 44-kDa rCIalpha1 fragment targeted for seed expression with an embryo-specific promoter were used. Factors to consider in efficient recovery processes are the distribution of the peptides among botanical parts and process recovery efficiency. Both recombinant proteins were distributed 62-64% in germ comprising about 8.6% of the dry grain mass; 34-38% in the endosperm comprising 84% of the dry grain mass; 1.7% in the pericarp comprising about 5% of the dry mass; and 1% in the tip-cap comprising 1.5-2% of the dry mass. The quick-germ method employed a short steeping period either in water or SO(2)-lactic acid solution followed by wet-milling degermination to recover a germ-rich fraction. Of the total recombinant protein expressed in germ, the quick-germ process recovered 40-43% of the total recombinant protein within 6-8% of the corn mass. The traditional corn wet-milling process produced higher purity germ but with lower recovery (24-26%) of the recombinant protein. The two quick-germ methods, using water alone or SO(2)-lactic acid steeping, did not substantially differ in rCIalpha1 recovery, and the quick-germ processes recovered germ with less leaching and proteolytic losses of the recombinant proteins than did traditional wet milling. Thus, grain fractionation enriched the recombinant proteins 6-fold higher than that of unfractionated kernels. Such enrichment may improve downstream processing efficiency and enable utilizing the protein-lean co-products to produce biofuels and biorenewable chemicals by fermenting the remaining starch-rich fractions.

  18. Modeling cell elongation during germ band retraction: cell autonomy versus applied anisotropic stress

    International Nuclear Information System (INIS)

    Lynch, Holley E; Shane Hutson, M; Veldhuis, Jim; Wayne Brodland, G

    2014-01-01

    The morphogenetic process of germ band retraction in Drosophila embryos involves coordinated movements of two epithelial tissues—germ band and amnioserosa. The germ band shortens along its rostral–caudal or head-to-tail axis, widens along its perpendicular dorsal-ventral axis, and uncurls from an initial ‘U’ shape. The amnioserosa mechanically assists this process by pulling on the crook of the U-shaped germ band. The amnioserosa may also provide biochemical signals that drive germ band cells to change shape in a mechanically autonomous fashion. Here, we use a finite-element model to investigate how these two contributions reshape the germ band. We do so by modeling the response to laser-induced wounds in each of the germ band’s spatially distinct segments (T1–T3, A1–A9) during the middle of retraction when segments T1–A3 form the ventral arm of the ‘U’, A4–A7 form its crook, and A8–A9 complete the dorsal arm. We explore these responses under a range of externally applied stresses and internal anisotropy of cell edge tensions—akin to a planar cell polarity that can drive elongation of cells in a direction parallel to the minimum edge tension—and identify regions of parameter space (edge-tension anisotropy versus stress anisotropy) that best match previous experiments for each germ band segment. All but three germ band segments are best fit when the applied stress anisotropy and the edge-tension anisotropy work against one another—i.e., when the isolated effects would elongate cells in perpendicular directions. Segments in the crook of the germ band (A4–A7) have cells that elongate in the direction of maximum external stress, i.e., external stress anisotropy is dominant. In most other segments, the dominant factor is internal edge-tension anisotropy. These results are consistent with models in which the amnioserosa pulls on the crook of the germ band to mechanically assist retraction. In addition, they suggest a mechanical cue for

  19. [Germ cell tumors - documentation of diagnosis and therapy by means of a web-based modular database system].

    Science.gov (United States)

    Schreiter, N; Jagota, A; Popken, G; Akhavuz, O; Nitzke, T; Düffelmeyer, M; Fischer, T; Schostak, M; Miller, K; Schrader, M

    2008-11-01

    Health telematics is gaining ground worldwide as it promises the bridging of distances in space and time as well as a highly effective use of financial and other resources. In Germany the development and introduction of a national telematic platform is in the foreground at present. However, there are a number of more specialised projects already in existence. The aim of this study was to develop an internet platform to document the quality of individual sections of treatment for patients with germ cell tumours in Berlin and to improve the therapy in conformity with the S2 guidelines. As a pilot project, a web-based modular database system (WBMDS) was developed, which can be used by any physician involved in the treatment of germ cell tumour patients from any computer connected to the internet. The WBMDS proved to be a practicable system of documentation. Data protection was ensured by pseudonyms as well as symmetrical and asymmetrical coding. The size of the extended documentation mask that had initially seemed to be necessary for valid documentation appeared to be too user-unfriendly with its 833 items. To meet the requirements of the user as well as of the documentation, a compact variant with 496 input fields was designed. On a random basis, treatment not in conformity with the guidelines could be detected in 20 % of 151 patients with the help of this system. For the successful use of an oncological database the following showed to be essential:[nl]Queries clearly defined for later statistical evaluation,[nl]clear separation between the phases of planning and implementation,[nl]a size of the database that does not make excessive demands on the user,[nl]intensive training of the users.[nl]The modular database system established proved to be well suitable for a quality-ensuring longitudinal case documentation, which can also be applied to other tumour entities.

  20. Generation of male germ cells from mouse induced pluripotent stem cells in vitro

    Directory of Open Access Journals (Sweden)

    Yangfang Li

    2014-03-01

    Full Text Available Germ cells are the only cell type that passes genetic information to the next generation. In most metazoan species, primordial germ cells (PGCs were induced from epiblasts by signals from the neighboring tissues. In vitro derivation of germ cells from the pluripotent stem cells (PSCs such as embryonic stem cells (ESCs and induced PSCs (iPSCs are of great values for the treatment of infertility, for animal breeding, and for studying the mechanism of germ cell development. Although the derivations of male germ cells from PSCs have been previously reported, most of the studies failed to conduct the induction in a well-controlled and highly efficient manner. Here, we report the derivation of induced PGC-like cells (iPGCLCs from mouse iPSCs via induced epiblast-like cells (iEpiLCs as being monitored by the expression of enhanced green fluorescent protein gene under the control of the promoter of stimulated by retinoic acid 8 (Stra8-EGFP. The identity of iPGCLCs was characterized by examining the expression of multiple marker genes as well as by the recovery of spermatogenesis after they were transplanted to the testis of infertile W/Wv mice. Furthermore, iPGCLCs were either induced to germline stem cell-like cells (iGSCLCs or reverted back to embryonic germ cell-like cells (iEGCLCs. In conclusion, we have established an efficient procedure for inducing iPSCs into iPGCLCs that can be further expanded and induced to more developed germ cells. This work indicates that the technology of in vitro germ cell induction is becoming more sophisticated and can be further improved.

  1. Molecular dosimetry of chemical mutagens: measurement of molecular dose and DNA repair germ cells

    International Nuclear Information System (INIS)

    Sega, G.A.

    1975-01-01

    Molecular dosimetry in the germ cells of male mice is reviewed with regard to in vivo alkylation of sperm heads, in vivo alkylation of sperm DNA, and possible alkylation of sperm protamine. DNA repair in male germ cells is reviewed with regard to basic design of experiments, DNA repair in various stages of spermatogenesis, effect of protamine on DNA repair following treatment with EMS or x radiation, and induction of DNA repair by methyl methanesulfonate, propyl methanesulfonate, and isopropyl methanesulfonate

  2. Management of germ cell tumors with somatic type malignancy: pathological features, prognostic factors and survival outcomes.

    Science.gov (United States)

    Rice, Kevin R; Magers, Martin J; Beck, Stephen D W; Cary, K Clint; Einhorn, Lawrence H; Ulbright, Thomas M; Foster, Richard S

    2014-11-01

    Germ cell tumors with somatic type malignancy are rare, occurring in approximately 2.7% to 8.6% of germ cell tumor cases. Prognostic factors and optimal management remain poorly defined. The Indiana University testis cancer database was queried from 1979 to 2011 for patients demonstrating germ cell tumor with somatic type malignancy at orchiectomy or subsequent resection. Patients with transformation to primitive neuroectodermal tumor only were excluded from study due to distinct management. Chart review, pathological review and survival analysis were performed. A total of 121 patients met the study inclusion criteria. The most common somatic type malignancy histologies were sarcoma (59), carcinoma (31) and sarcomatoid yolk sac tumor (17). Of these patients 32 demonstrated somatic type malignancy at germ cell tumor diagnosis. For those with delayed identification, median time from germ cell tumor to somatic type malignancy diagnosis was 33 months. This interval was longest for carcinomas (108 months). At a median followup of 71 months, 5-year cancer specific survival was 64%. Predictors of poorer cancer specific survival included somatic type malignancy diagnosed at late relapse (p = 0.017), referral to Indiana University for reoperative retroperitoneal lymph node dissection (p = 0.026) and grade (p = 0.026). None of these factors maintained prognostic significance on multivariate analysis. Somatic type malignancy histology subtype, stage, risk category and number of resections were not predictive of cancer specific survival. Germ cell tumor with somatic type malignancy is associated with poorer cancer specific survival than traditional germ cell tumor. Established prognostic factors for germ cell tumor lose predictive value in the setting of somatic type malignancy. Aggressive and serial resections are often necessary to optimize cancer specific survival. Tumor grade is an important prognostic factor in sarcomas and sarcomatoid yolk sac tumors. Copyright

  3. Expression of a linker histone-like gene in the primordial germ cells in zebrafish

    OpenAIRE

    Müller, Katja; Thisse, Christine; Thisse, Bernard; Raz, Erez

    2002-01-01

    Similar to many other organisms, specification of primordial germ cells (PGCs) in zebraftsh occurs during early development and depends on inheritance of 'germ plasm' determinants. Following their specification, the PGCs exhibit characteristic transcriptional profile and cell behaviour. Here we describe the cloning, expression pattern and sub-cellular localization of the zebrafish H I type linker histone, HIM, which is specifically expressed in the PGCs in the second phase of their developmen...

  4. Bmp4 is required for the generation of primordial germ cells in the mouse embryo

    OpenAIRE

    Lawson, Kirstie A.; Dunn, N. Ray; Roelen, Bernard A.J.; Zeinstra, Laura M.; Davis, Angela M.; Wright, Christopher V.E.; Korving, Jeroen P.W.F.M.; Hogan, Brigid L.M.

    1999-01-01

    In many organisms the allocation of primordial germ cells (PGCs) is determined by the inheritance of maternal factors deposited in the egg. However, in mammals, inductive cell interactions are required around gastrulation to establish the germ line. Here, we show that Bmp4 homozygous null embryos contain no PGCs. They also lack an allantois, an extraembryonic mesodermal tissue derived, like the PGCs, from precursors in the proximal epiblast. Heterozygotes have fewer PGCs than normal, due to a...

  5. Dearth and Delayed Maturation of Testicular Germ Cells in Fanconi Anemia E Mutant Male Mice.

    Directory of Open Access Journals (Sweden)

    Chun Fu

    Full Text Available After using a self-inactivating lentivirus for non-targeted insertional mutagenesis in mice, we identified a transgenic family with a recessive mutation that resulted in reduced fertility in homozygous transgenic mice. The lentiviral integration site was amplified by inverse PCR. Sequencing revealed that integration had occurred in intron 8 of the mouse Fance gene, which encodes the Fanconi anemia E (Fance protein. Fanconi anemia (FA proteins play pivotal roles in cellular responses to DNA damage and Fance acts as a molecular bridge between the FA core complex and Fancd2. To investigate the reduced fertility in the mutant males, we analyzed postnatal development of testicular germ cells. At one week after birth, most tubules in the mutant testes contained few or no germ cells. Over the next 2-3 weeks, germ cells accumulated in a limited number of tubules, so that some tubules contained germ cells around the full periphery of the tubule. Once sufficient numbers of germ cells had accumulated, they began to undergo the later stages of spermatogenesis. Immunoassays revealed that the Fancd2 protein accumulated around the periphery of the nucleus in normal developing spermatocytes, but we did not detect a similar localization of Fancd2 in the Fance mutant testes. Our assays indicate that although Fance mutant males are germ cell deficient at birth, the extant germ cells can proliferate and, if they reach a threshold density, can differentiate into mature sperm. Analogous to previous studies of FA genes in mice, our results show that the Fance protein plays an important, but not absolutely essential, role in the initial developmental expansion of the male germ line.

  6. Maternal age effect and severe germ-line bottleneck in the inheritance of human mitochondrial DNA

    DEFF Research Database (Denmark)

    Rebolledo-Jaramillo, Boris; Su, Marcia Shu-Wei; Stoler, Nicholas

    2014-01-01

    generations and estimated the effective size of the germ-line mtDNA bottleneck at only ∼30-35 (interquartile range from 9 to 141). Accounting for heteroplasmies, we estimated the mtDNA germ-line mutation rate at 1.3 × 10(-8) (interquartile range from 4.2 × 10(-9) to 4.1 × 10(-8)) mutations per site per year...

  7. Localisation of RNAs into the germ plasm of vitellogenic Xenopus oocytes.

    Directory of Open Access Journals (Sweden)

    Sarbjit Nijjar

    Full Text Available We have studied the localisation of mRNAs in full-grown Xenopus laevis oocytes by injecting fluorescent RNAs, followed by confocal microscopy of the oocyte cortex. Concentrating on RNA encoding the Xenopus Nanos homologue, nanos1 (formerly Xcat2, we find that it consistently localised into aggregated germ plasm ribonucleoprotein (RNP particles, independently of cytoskeletal integrity. This implies that a diffusion/entrapment-mediated mechanism is active, as previously reported for previtellogenic oocytes. Sometimes this was accompanied by localisation into scattered particles of the "late", Vg1/VegT pathway; occasionally only late pathway localisation was seen. The Xpat RNA behaved in an identical fashion and for neither RNA was the localisation changed by any culture conditions tested. The identity of the labelled RNP aggregates as definitive germ plasm was confirmed by their inclusion of abundant mitochondria and co-localisation with the germ plasm protein Hermes. Further, the nanos1/Hermes RNP particles are interspersed with those containing the germ plasm protein Xpat. These aggregates may be followed into the germ plasm of unfertilized eggs, but with a notable reduction in its quantity, both in terms of injected molecules and endogenous structures. Our results conflict with previous reports that there is no RNA localisation in large oocytes, and that during mid-oogenesis even germ plasm RNAs localise exclusively by the late pathway. We find that in mid oogenesis nanos1 RNA also localises to germ plasm but also by the late pathway. Late pathway RNAs, Vg1 and VegT, also may localise into germ plasm. Our results support the view that mechanistically the two modes of localisation are extremely similar, and that in an injection experiment RNAs might utilise either pathway, the distinction in fates being very subtle and subject to variation. We discuss these results in relation to their biological significance and the results of others.

  8. Involvement of epigenetic modifiers in the pathogenesis of testicular dysgenesis and germ cell cancer

    DEFF Research Database (Denmark)

    Lawaetz, Andreas C.; Almstrup, Kristian

    2015-01-01

    cell is a fetal germ cell that has been arrested during development due to testicular dysgenesis. CIS cells retain a fetal and open chromatin structure, and recently several epigenetic modifiers have been suggested to be involved in testicular dysgenesis in mice. We here review the possible involvement...... of epigenetic modifiers with a focus on jumonji C enzymes in the development of testicular dysgenesis and germ cell cancer in men....

  9. European consensus conference on diagnosis and treatment of germ cell cancer: a report of the second meeting of the European Germ Cell Cancer Consensus group (EGCCCG): part I

    DEFF Research Database (Denmark)

    Krege, Susanne; Beyer, Jörg; Souchon, Rainer

    2007-01-01

    OBJECTIVES: The first consensus report presented by the European Germ Cell Cancer Consensus Group (EGCCCG) in the year 2004 has found widespread approval by many colleagues throughout the world. In November 2006, the group met a second time under the auspices of the Department of Urology of the A......OBJECTIVES: The first consensus report presented by the European Germ Cell Cancer Consensus Group (EGCCCG) in the year 2004 has found widespread approval by many colleagues throughout the world. In November 2006, the group met a second time under the auspices of the Department of Urology...

  10. A late phase of germ plasm accumulation during Drosophila oogenesis requires Lost and Rumpelstiltskin

    Science.gov (United States)

    Sinsimer, Kristina S.; Jain, Roshan A.; Chatterjee, Seema; Gavis, Elizabeth R.

    2011-01-01

    Asymmetric mRNA localization is an effective mechanism for establishing cellular and developmental polarity. Posterior localization of oskar in the Drosophila oocyte targets the synthesis of Oskar to the posterior, where Oskar initiates the assembly of the germ plasm. In addition to harboring germline determinants, the germ plasm is required for localization and translation of the abdominal determinant nanos. Consequently, failure of oskar localization during oogenesis results in embryos lacking germ cells and abdominal segments. oskar accumulates at the oocyte posterior during mid-oogenesis through a well-studied process involving kinesin-mediated transport. Through live imaging of oskar mRNA, we have uncovered a second, mechanistically distinct phase of oskar localization that occurs during late oogenesis and results in amplification of the germ plasm. Analysis of two newly identified oskar localization factors, Rumpelstiltskin and Lost, that are required specifically for this late phase of oskar localization shows that germ plasm amplification ensures robust abdomen and germ cell formation during embryogenesis. In addition, our results indicate the importance of mechanisms for adapting mRNAs to utilize multiple localization pathways as necessitated by the dramatic changes in ovarian physiology that occur during oogenesis. PMID:21752933

  11. Testicular germ cell cancer despite previous local radiotherapy to the testis.

    Science.gov (United States)

    Dieckmann, K-P; Lauke, H; Michl, U; Winter, E; Loy, V

    2002-06-01

    Testicular intraepithelial neoplasia (TIN, also carcinoma in situ of the testis) is the uniform precursor of testicular germ cell cancer. Local radiotherapy to the testis with dosages of 18-20 Gy has been found to safely eradicate TIN and germ cells, too. Thus, the general assumption is that the development of invasive germ cell tumours can be prevented by this radiotherapy. Herein, we report two patients with one-sided testicular tumour and biopsy-proven contralateral TIN. Both of them developed germ cell neoplasms in the remaining testis although local radiotherapy with 20 Gy had been applied to the testis. One patient developed pure seminoma 7 years after completion of radiotherapy, the other developed a combined tumour consisting of embryonal carcinoma and seminoma after 5 years. Treatment consisted of orchiectomy in each of the cases. Histologically, both had TIN in the testicular tissue surrounding the new growths. Pathogenetically, a small fraction of radioresistent TIN cells overcoming irradiation and progressing to full-blown germ cell cancer in the later course may be the histogenetic clue to explain these unexpected events. Other explanations, though less probable, could be technical radiotherapeutic failure due to targeting problems and a pre-existing radioresistent germ cell tumour in the irradiated testicle.

  12. Mouse Germ Cell Development in-vivo and in-vitro

    Directory of Open Access Journals (Sweden)

    Deshira Saiti

    2007-01-01

    Full Text Available In mammalian development, primordial germ cells (PGCs represent the initial population of cells that are committed to the germ cell lineage. PGCs segregate early in development, triggered by signals from the extra-embryonic ectoderm. They are distinguished from surrounding cells by their unique gene expression patterns. Some of the more common genes used to identify them are Blimp1, Oct3/4, Fragilis, Stella, c-Kit, Mvh, Dazl and Gcna1. These genes are involved in regulating their migration and differentiation, and in maintaining the pluripotency of these cells. Recent research has demonstrated the possibility of obtaining PGCs, and subsequently, mature germ cells from a starting population of embryonic stem cells (ESCs in culture. This phenomenon has been investigated using a variety of methods, and ESC lines of both mouse and human origin. Embryonic stem cells can differentiate into germ cells of both the male and female phenotype and in one case has resulted in the birth of live pups from the fertilization of oocytes with ESC derived sperm. This fi nding leads to the prospect of using ESC derived germ cells as a treatment for sterility. This review outlines the evolvement of germ cells from ESCs in vitro in relation to in vivo events.

  13. Stochastic specification of primordial germ cells from mesoderm precursors in axolotl embryos.

    Science.gov (United States)

    Chatfield, Jodie; O'Reilly, Marie-Anne; Bachvarova, Rosemary F; Ferjentsik, Zoltan; Redwood, Catherine; Walmsley, Maggie; Patient, Roger; Loose, Mathew; Johnson, Andrew D

    2014-06-01

    A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these disparate mechanisms of PGC specification evolved is unknown. Here, in order to identify the ancestral mechanism of PGC specification in vertebrates, we studied PGC specification in embryos from the axolotl (Mexican salamander), a model for the tetrapod ancestor. In the axolotl, PGCs develop within mesoderm, and classic studies have reported their induction from primitive ectoderm (animal cap). We used an axolotl animal cap system to demonstrate that signalling through FGF and BMP4 induces PGCs. The role of FGF was then confirmed in vivo. We also showed PGC induction by Brachyury, in the presence of BMP4. These conditions induced pluripotent mesodermal precursors that give rise to a variety of somatic cell types, in addition to PGCs. Irreversible restriction of the germ line did not occur until the mid-tailbud stage, days after the somatic germ layers are established. Before this, germline potential was maintained by MAP kinase signalling. We propose that this stochastic mechanism of PGC specification, from mesodermal precursors, is conserved in vertebrates. © 2014. Published by The Company of Biologists Ltd.

  14. Primordial germ cell-like cells differentiated in vitro from skin-derived stem cells.

    Directory of Open Access Journals (Sweden)

    Katja Linher

    Full Text Available BACKGROUND: We have previously demonstrated that stem cells isolated from fetal porcine skin have the potential to form oocyte-like cells (OLCs in vitro. However, primordial germ cells (PGCs, which must also be specified during the stem cell differentiation to give rise to these putative oocytes at more advanced stages of culture, were not systematically characterized. The current study tested the hypothesis that a morphologically distinct population of cells derived from skin stem cells prior to OLC formation corresponds to putative PGCs, which differentiate further into more mature gametes. METHODOLOGY/PRINCIPAL FINDINGS: When induced to differentiate in an appropriate microenvironment, a subpopulation of morphologically distinct cells, some of which are alkaline phosphatase (AP-positive, also express Oct4, Fragilis, Stella, Dazl, and Vasa, which are markers indicative of germ cell formation. A known differentially methylated region (DMR within the H19 gene locus, which is demethylated in oocytes after establishment of the maternal imprint, is hypomethylated in PGC-like cells compared to undifferentiated skin-derived stem cells, suggesting that the putative germ cell population undergoes imprint erasure. Additional evidence supporting the germ cell identity of in vitro-generated PGC-like cells is that, when labeled with a Dazl-GFP reporter, these cells further differentiate into GFP-positive OLCs. SIGNIFICANCE: The ability to generate germ cell precursors from somatic stem cells may provide an in vitro model to study some of the unanswered questions surrounding early germ cell formation.

  15. [The role of pulp in the root resorption of primary teeth without permanent tooth germs].

    Science.gov (United States)

    Lin, Bi-chen; Yang, Jie; Zhao, Yu-ming; Ge, Li-hong

    2011-03-01

    To investigate the role of pulp in the root resorption of primary teeth without permanent tooth germs. The animal model without permanent tooth germs was established by surgery in Beagle dog. The root resorption was observed by taking periapical radiographs periodically. The samples of mandibular bone and pulp at different resorption stages were collected. The distribution of odontoclasts and the activating factor was analyzed by histological staining and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The role of pulp in the root resorption of primary teeth was tested by early pulpectomy. In the root resorption of primary molars without permanent teeth germs, a large number of odontoclasts were present on the pulpal surface of the root canal. Semi-quantification RT-PCR showed that the ratios of the expression of receptor activator of NF-κB ligand (RANKL) mRNA and β-actin in the pulp of permanent teeth and primary teeth without permanent teeth germ during different periods of root resorption are 0.1314, 0.1901, 0.2111 and 0.6058 (P > 0.05). The root resorption of primary teeth without permanent teeth germs in test groups was about 5 weeks later than that of control group. The pulp of primary tooth played an important role in the root resorption of primary tooth without permanent tooth germ.

  16. Locally orderless registration code

    DEFF Research Database (Denmark)

    2012-01-01

    This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows.......This is code for the TPAMI paper "Locally Orderless Registration". The code requires intel threadding building blocks installed and is provided for 64 bit on mac, linux and windows....

  17. Error Correcting Codes

    Indian Academy of Sciences (India)

    sound quality is, in essence, obtained by accurate waveform coding and decoding of the audio signals. In addition, the coded audio information is protected against disc errors by the use of a Cross Interleaved Reed-Solomon Code (CIRC). Reed-. Solomon codes were discovered by Irving Reed and Gus Solomon in 1960.

  18. La fuga imaginaria de Germán Colmenares

    Directory of Open Access Journals (Sweden)

    Isidro Vanegas

    2015-01-01

    Full Text Available El ensayo en que Germán Colmenares califica de prisión historiográfica a la Historia de la revolución de José Manuel Restrepo sigue siendo considerado una verdad de a puño. Allí Colmenares deconstruye una obra que juzga como un obstáculo para comprender el acontecimiento revolucionario y, a la vez, como la matriz de la conciencia colombiana sobre sus propios orígenes, en la que habrían quedado aprisionados los historiadores. Este artículo se ocupa de impugnar ambos asertos, mostrando cómo la obra de Restrepo no gozó entre los publicistas del siglo XIX de la autoridad que se le adjudica, y no pudo ser, por lo tanto, a través de ella que los padres de la patria construyeron su mito y la Nueva Granada su propia imagen como asociación política.

  19. Tumour markers in germ cell tumours and thyroid cancer

    International Nuclear Information System (INIS)

    Mann, K.

    1988-01-01

    In patients with germ cell tumours of gonadal and extragonadal origin both markers, human chorionic gonadotropin (hCG) and alphafetoprotein (AFP) are madatory for diagnosis and control of treatment. In seminoma, we found preoperatively elevated levels of hCG(+hCG-β) in 42/349 patients (12%) up to 1200 mlU/ml using a polyclonal radioimmunoassay (1. IRP hCG standard 75/537). Lactatedehydrogenase can be useful in marker negative patients. Serum levels reflect tumour burden even if not highly specific. Presently, placental alkaline phosphatase is under discussion for seminoma. However, commercial kits are not available. As a relatively high secretion of hCG/β/hCG was found in gestational trophoblastic diseases, this parameters may be useful for differential diagnosis in pregnancy. In the follow-up of patients with differentiated thyroid carcinoma the determination of thyroglobulin (Tg) in combination with ultrasound of the thyroid and X-ray of the chest is sufficient. For Tg-determination thyroid hormone replacement therapy must be discontinued only in rare single cases with borderline levels, which need radioiodtesting additionally. Calcitonin is the most important marker in medullary thyroid carcinoma. Pentagastrin stimulated calcitonin as screening test is necessary, if multiple endocrine adenomatosis or the familial forms are suspected. In single cases benefit came from new scintigraphic methods such as 131 I-metaiodo-benzylguanidine or 201 thallium-chloride. (orig./MG) [de

  20. Interspecific germline transmission of cultured primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Marie-Cecile van de Lavoir

    Full Text Available In birds, the primordial germ cell (PGC lineage separates from the soma within 24 h following fertilization. Here we show that the endogenous population of about 200 PGCs from a single chicken embryo can be expanded one million fold in culture. When cultured PGCs are injected into a xenogeneic embryo at an equivalent stage of development, they colonize the testis. At sexual maturity, these donor PGCs undergo spermatogenesis in the xenogeneic host and become functional sperm. Insemination of semen from the xenogeneic host into females from the donor species produces normal offspring from the donor species. In our model system, the donor species is chicken (Gallus domesticus and the recipient species is guinea fowl (Numida meleagris, a member of a different avian family, suggesting that the mechanisms controlling proliferation of the germline are highly conserved within birds. From a pragmatic perspective, these data are the basis of a novel strategy to produce endangered species of birds using domesticated hosts that are both tractable and fecund.

  1. The dynamic cytoskeleton of the developing male germ cell.

    Science.gov (United States)

    Sperry, Ann O

    2012-05-01

    Mammalian spermatogenesis is characterised by dramatic cellular change to transform the non-polar spermatogonium into a highly polarised and functional spermatozoon. The acquisition of cell polarity is a requisite step for formation of viable sperm. The polarity of the spermatozoon is clearly demonstrated by the acrosome at the apical pole of the cell and the flagellum at the opposite end. Spermatogenesis consists of three basic phases: mitosis, meiosis and spermiogenesis. The final phase represents the period of greatest cellular change where cell-type specific organelles such as the acrosome and the flagellum form, the nucleus migrates to the plasma membrane and elongates, chromatin condenses and residual cytoplasm is removed. An important feature of spermatogenesis is the change in the cytoskeleton that occurs throughout this pathway. In this review, the author will provide an overview of these transformations and provide insight into possible modes of regulation of these rearrangements during spermatogenesis. Although primary focus will be given to the microtubule cytoskeleton, the importance of actin filaments to the cellular transformation of the male germ cell will also be discussed. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

  2. Poultry genetic resource conservation using primordial germ cells

    Science.gov (United States)

    NAKAMURA, Yoshiaki

    2016-01-01

    The majority of poultry genetic resources are maintained in situ in living populations. However, in situ conservation of poultry genetic resources always carries the risk of loss owing to pathogen outbreaks, genetic problems, breeding cessation, or natural disasters. Cryobanking of germplasm in birds has been limited to the use of semen, preventing conservation of the W chromosome and mitochondrial DNA. A further challenge is posed by the structure of avian eggs, which restricts the cryopreservation of ova and fertilized embryos, a technique widely used for mammalian species. By using a unique biological property and accessibility of avian primordial germ cells (PGCs), precursor cells for gametes, which temporally circulate in the vasculature during early development, an avian PGC transplantation technique has been established. To date, several techniques for PGC manipulation including purification, cryopreservation, depletion, and long-term culture have been developed in chickens. PGC transplantation combined with recent advanced PGC manipulation techniques have enabled ex situ conservation of poultry genetic resources in their complete form. Here, the updated technologies for avian PGC manipulation are introduced, and then the concept of a poultry PGC-bank is proposed by considering the biological properties of avian PGCs. PMID:27210834

  3. The origin and migration of primordial germ cells in sturgeons.

    Directory of Open Access Journals (Sweden)

    Taiju Saito

    Full Text Available Primordial germ cells (PGCs arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts.

  4. Cultivation and Biological Characterization of Chicken Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Meng Ji

    2016-01-01

    Full Text Available The purpose of this work was to investigate the isolation, culture process of chicken gonadal primordial germ cells (PGCs and study their biological characterization. PGCs were harvested from 5.5-day-old chicken embryonic genital ridges and explanted onto chicken embryonic fibroblasts (CEFs. The results showed that the primary cultivation of chicken PGCs on their own gonadal stroma cells were better than CEFs at first two days for reproduction. The conditioned media supported the growth and colony formation of PGCs for a prolonged time in vitro and maintained a normal diploid karyotype, which were positively stained by alkaline phosphatase (AKP, periodic acid Schiff (PAS and reacted with anti-SSEA-1, SSEA-3, Oct4, Blimp1 and Sox2. Real-time PCR showed that they expressed the stage specific genes CVH, Blimp1 and Dazl, the stem cell specific genes Sox2, Pouv and Nanog. They also formed the embryoid bodies (EBs. These results suggested that the chicken PGCs cultured in vitro not only had strong self-renewal ability, but also had the potential capability of multi-lineage differentiation.

  5. The Origin And Migration Of Primordial Germ Cells In Sturgeons

    Science.gov (United States)

    Saito, Taiju; Pšenička, Martin; Goto, Rie; Adachi, Shinji; Inoue, Kunio; Arai, Katsutoshi; Yamaha, Etsuro

    2014-01-01

    Primordial germ cells (PGCs) arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser) have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT) assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts. PMID:24505272

  6. A pilgrim's progress: Seeking meaning in primordial germ cell migration

    Directory of Open Access Journals (Sweden)

    Andrea V. Cantú

    2017-10-01

    Full Text Available Comparative studies of primordial germ cell (PGC development across organisms in many phyla reveal surprising diversity in the route of migration, timing and underlying molecular mechanisms, suggesting that the process of migration itself is conserved. However, beyond the perfunctory transport of cellular precursors to their later arising home of the gonads, does PGC migration serve a function? Here we propose that the process of migration plays an additional role in quality control, by eliminating PGCs incapable of completing migration as well as through mechanisms that favor PGCs capable of responding appropriately to migration cues. Focusing on PGCs in mice, we explore evidence for a selective capacity of migration, considering the tandem regulation of proliferation and migration, cell-intrinsic and extrinsic control, the potential for tumors derived from failed PGC migrants, the potential mechanisms by which migratory PGCs vary in their cellular behaviors, and corresponding effects on development. We discuss the implications of a selective role of PGC migration for in vitro gametogenesis.

  7. A pilgrim's progress: Seeking meaning in primordial germ cell migration.

    Science.gov (United States)

    Cantú, Andrea V; Laird, Diana J

    2017-10-01

    Comparative studies of primordial germ cell (PGC) development across organisms in many phyla reveal surprising diversity in the route of migration, timing and underlying molecular mechanisms, suggesting that the process of migration itself is conserved. However, beyond the perfunctory transport of cellular precursors to their later arising home of the gonads, does PGC migration serve a function? Here we propose that the process of migration plays an additional role in quality control, by eliminating PGCs incapable of completing migration as well as through mechanisms that favor PGCs capable of responding appropriately to migration cues. Focusing on PGCs in mice, we explore evidence for a selective capacity of migration, considering the tandem regulation of proliferation and migration, cell-intrinsic and extrinsic control, the potential for tumors derived from failed PGC migrants, the potential mechanisms by which migratory PGCs vary in their cellular behaviors, and corresponding effects on development. We discuss the implications of a selective role of PGC migration for in vitro gametogenesis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Tumour markers in germ cell tumours and thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mann, K.

    1988-02-01

    In patients with germ cell tumours of gonadal and extragonadal origin both markers, human chorionic gonadotropin (hCG) and alphafetoprotein (AFP) are madatory for diagnosis and control of treatment. In seminoma, we found preoperatively elevated levels of hCG(+hCG-..beta..) in 42/349 patients (12%) up to 1200 mlU/ml using a polyclonal radioimmunoassay (1. IRP hCG standard 75/537). Lactatedehydrogenase can be useful in marker negative patients. Serum levels reflect tumour burden even if not highly specific. Presently, placental alkaline phosphatase is under discussion for seminoma. However, commercial kits are not available. As a relatively high secretion of hCG/..beta../hCG was found in gestational trophoblastic diseases, this parameters may be useful for differential diagnosis in pregnancy. In the follow-up of patients with differentiated thyroid carcinoma the determination of thyroglobulin (Tg) in combination with ultrasound of the thyroid and X-ray of the chest is sufficient. For Tg-determination thyroid hormone replacement therapy must be discontinued only in rare single cases with borderline levels, which need radioiodtesting additionally. Calcitonin is the most important marker in medullary thyroid carcinoma. Pentagastrin stimulated calcitonin as screening test is necessary, if multiple endocrine adenomatosis or the familial forms are suspected. In single cases benefit came from new scintigraphic methods such as /sup 131/I-metaiodo-benzylguanidine or /sup 201/thallium-chloride.

  9. Germ Cell Cancer and Multiple Relapses: Toxicity and Survival

    DEFF Research Database (Denmark)

    Lauritsen, Jakob; Kier, Maria G.G.; Mortensen, Mette S.

    2015-01-01

    Purpose: A small number of patients with germ cell cancer (GCC) receive more than one line of treatment for disseminated disease. The purpose of this study was to evaluate late toxicity and survival in an unselected cohort of patients who experienced relapse after receiving first-line treatment...... for disseminated disease. Methods: From the Danish Testicular Cancer database, we identified all patients who received more than one line of treatment for disseminated disease. Information about late toxicity and mortality was obtained by means of linkage to national registers. Prognostic factors for relapse......, compared with patients treated with only orchiectomy, had an increased risk for a second cancer (hazard ratio [HR], 3.2; 95% CI, 1.9 to 5.5), major cardiovascular disease (HR, 1.9; 95% CI, 1.0 to 3.3), pulmonary disease (HR, 2.0; 95% CI, 1.0 to 3.8), GI disease (HR, 7.3; 95% CI, 3.6 to 14.8), renal...

  10. Genome Editing Mediated by Primordial Germ Cell in Chicken.

    Science.gov (United States)

    Han, Jae Yong; Lee, Hong Jo

    2017-01-01

    Rapid development of genome editing technology has facilitated the studies on exploring specific gene functions and establishment of model animals. In livestock, the technology has contributed to create high value in industry fields, e.g., enhancing productivity or acquiring the resistance against disease. Meanwhile, genome editing in avian species has been emphasized because of their applicable possibilities in terms of highly productive chickens, disease-controlled avian lines, and development of novel biological models. Induction of exogenous gene using virus system or transposition in chicken primordial germ cells (PGCs) has been widely used for producing transgenic chicken, and recently developed programmable genome editing (PGE) technologies such as tale transcription activator-like effector nuclease (TALEN) and clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated (Cas9) are expected to maximize the applicable potentials of avian species. In this regard, this chapter will cover the methods for producing genome-edited chicken by piggyBac transposition and gene targeting technology, TALEN, and CRISPR/Cas9.

  11. Network Coding Taxonomy

    OpenAIRE

    Adamson , Brian; Adjih , Cédric; Bilbao , Josu; Firoiu , Victor; Fitzek , Frank; Samah , Ghanem ,; Lochin , Emmanuel; Masucci , Antonia; Montpetit , Marie-Jose; Pedersen , Morten V.; Peralta , Goiuri; Roca , Vincent; Paresh , Saxena; Sivakumar , Senthil

    2017-01-01

    Internet Research Task Force - Working document of the Network Coding Research Group (NWCRG), draft-irtf-nwcrg-network-coding-taxonomy-05 (work in progress), https://datatracker.ietf.org/doc/draft-irtf-nwcrg-network-coding-taxonomy/; This document summarizes a recommended terminology for Network Coding concepts and constructs. It provides a comprehensive set of terms with unique names in order to avoid ambiguities in future Network Coding IRTF and IETF documents. This document is intended to ...

  12. QR Codes 101

    Science.gov (United States)

    Crompton, Helen; LaFrance, Jason; van 't Hooft, Mark

    2012-01-01

    A QR (quick-response) code is a two-dimensional scannable code, similar in function to a traditional bar code that one might find on a product at the supermarket. The main difference between the two is that, while a traditional bar code can hold a maximum of only 20 digits, a QR code can hold up to 7,089 characters, so it can contain much more…

  13. Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats.

    Science.gov (United States)

    Surampudi, P; Chang, I; Lue, Y; Doumit, T; Jia, Y; Atienza, V; Liu, P Y; Swerdloff, R S; Wang, C

    2015-05-01

    Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I-VI) and late stages (IX-XIV) but not at middle stages (VII-VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII-VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low. © 2015 American Society of Andrology

  14. Humanin protects against chemotherapy-induced stage-specific male germ cell apoptosis in rats*

    Science.gov (United States)

    Lue, Y.; Doumit, T.; Jia, Y.; Atienza, V.; Liu, P. Y.; Swerdloff, R. S.; Wang, C.

    2016-01-01

    SUMMARY Humanin (HN) has cytoprotective action on male germ cells after testicular stress induced by heat and hormonal deprivation. To examine whether HN has protective effects on chemotherapy-induced male germ cell apoptosis, we treated four groups of adult rats with (i) vehicle (control), (ii) HN, (iii) cyclophosphamide (CP); or (iv) HN+CP. To investigate whether the protective effects of HN on germ cells require the presence of Leydig cells, another four groups of rats were pre-treated with ethane dimethanesulfonate (EDS), a Leydig cell toxicant, to eliminate Leydig cells. After 3 days, when Leydig cells were depleted by EDS, we administered: (i) vehicle, (ii) HN, (iii) CP; or (iv) HN+CP to rats. All rats were killed 12 h after the injection of HN and/or CP. Germ cell apoptosis was detected by TUNEL assay and quantified by numerical count. Compared with control and HN (alone), CP significantly increased germ cell apoptosis; HN +CP significantly reduced CP-induced apoptosis at early (I–VI) and late stages (IX–XIV) but not at middle stages (VII–VIII) of the seminiferous epithelial cycle. Pre-treatment with EDS markedly suppressed serum and intratesticular testosterone (T) levels, and significantly increased germ cell apoptosis at the middle (VII–VIII) stages. CP did not further increase germ cell apoptosis in the EDS-pre-treated rats. HN significantly attenuated germ cell apoptosis at the middle stages in EDS pre-treated rats. To investigate whether HN has any direct effects on Leydig cell function, adult Leydig cells were isolated and treated with ketoconazole (KTZ) to block testosterone synthesis. HN was not effective in preventing the reduction of T production by KTZ in vitro. We conclude that HN decreases CP and/or EDS-induced germ cell apoptosis in a stage-specific fashion. HN acts directly on germ cells to protect against EDS-induced apoptosis in the absence of Leydig cells and intratesticular testosterone levels are very low. PMID:25891800

  15. Radiation transport simulation of the Martian GCR surface flux and dose estimation using spherical geometry in PHITS compared to MSL-RAD measurements.

    Science.gov (United States)

    Flores-McLaughlin, John

    2017-08-01

    Planetary bodies and spacecraft are predominantly exposed to isotropic radiation environments that are subject to transport and interaction in various material compositions and geometries. Specifically, the Martian surface radiation environment is composed of galactic cosmic radiation, secondary particles produced by their interaction with the Martian atmosphere, albedo particles from the Martian regolith and occasional solar particle events. Despite this complex physical environment with potentially significant locational and geometric dependencies, computational resources often limit radiation environment calculations to a one-dimensional or slab geometry specification. To better account for Martian geometry, spherical volumes with respective Martian material densities are adopted in this model. This physical description is modeled with the PHITS radiation transport code and compared to a portion of measurements from the Radiation Assessment Detector of the Mars Science Laboratory. Particle spectra measured between 15 November 2015 and 15 January 2016 and PHITS model results calculated for this time period are compared. Results indicate good agreement between simulated dose rates, proton, neutron and gamma spectra. This work was originally presented at the 1st Mars Space Radiation Modeling Workshop held in 2016 in Boulder, CO. Copyright © 2017. Published by Elsevier Ltd.

  16. Efficient Coding of Information: Huffman Coding -RE ...

    Indian Academy of Sciences (India)

    1. Introduction. Shannon's landmark paper 'A Mathematical Theory of. Communication' [1] laid the foundation for communica- ... coding theory, codes over graphs and iterative techniques, and informa- tion theory. .... An important consequence of independence is that if. {Xb X2 , . Xn} are independent random variables, each.

  17. Turbo Codes Extended with Outer BCH Code

    DEFF Research Database (Denmark)

    Andersen, Jakob Dahl

    1996-01-01

    The "error floor" observed in several simulations with the turbo codes is verified by calculation of an upper bound to the bit error rate for the ensemble of all interleavers. Also an easy way to calculate the weight enumerator used in this bound is presented. An extended coding scheme is proposed...

  18. Sexual dimorphic expression of dnd in germ cells during sex reversal and its requirement for primordial germ cell survival in protogynous hermaphroditic grouper.

    Science.gov (United States)

    Sun, Zhi-Hui; Zhou, Li; Li, Zhi; Liu, Xiao-Chun; Li, Shui-Sheng; Wang, Yang; Gui, Jian-Fang

    2017-06-01

    Dead end (dnd), vertebrate-specific germ cell marker, had been demonstrated to be essential for primordial germ cell (PGC) migration and survival, and the link between PGC number and sex change had been revealed in some teleost species, but little is known about dnd in hermaphroditic vertebrates. In the present study, a protogynous hermaphroditic orange-spotted grouper (Epinephelus coioides) dnd homologue (Ecdnd) was identified and characterized. Quantitative real-time PCR and in situ hybridization analysis revealed a dynamic and sexually dimorphic expression pattern in PGCs and germ cells of gonads. During sex changing, the Ecdnd transcript sharply increased in early transitional gonad, reached the highest level at late transitional gonad stage, and decreased after testis maturation. Visualization of zebrafish PGCs by injecting with RFP-Ecdnd-3'UTR RNA and GFP-zfnanos3-3'UTR RNA confirmed importance of Ecdnd 3'UTR for the PGC distribution. In addition, knockdown of EcDnd by using antisense morpholinos (MO) caused the ablation of PGCs in orange-spotted grouper. Therefore, the current data indicate that Ecdnd is essential for PGCs survival and may serve as a useful germ cell marker during gametogenesis in hermaphroditic grouper. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. European consensus conference on diagnosis and treatment of germ cell cancer: a report of the second meeting of the European Germ Cell Cancer Consensus Group (EGCCCG): part II

    DEFF Research Database (Denmark)

    Krege, Susanne; Beyer, Jörg; Souchon, Rainer

    2007-01-01

    OBJECTIVES: The first consensus report that had been presented by the European Germ Cell Cancer Consensus Group (EGCCCG) in 2004 has found widespread approval by many colleagues throughout the world. In November 2006, the group met a second time under the auspices of the Department of Urology...

  20. When the GERM Hosts the Antidote: The Surprising New Birth of Israel's Anti-GERM Pre-K Policy

    Science.gov (United States)

    Bialik, Gadi; Shefi, Noa

    2017-01-01

    Since the 1970s, Israel's educational policy has been undergoing a change generated by the neo-liberal agenda. In this light, it is not surprising that since the 1990s, Israel's education system has adopted the main characteristics of the Global Education Reform Movement (GERM). In light of this, the current research will focus on a newly born…

  1. Clinical use of serum TRA-1-60 as tumor marker in patients with germ cell cancer

    DEFF Research Database (Denmark)

    Lajer, Henrik; Daugaard, Gedske; Andersson, Anna-Maria

    2002-01-01

    TRA-1-60 antigen has been related to the presence of embryonal germ cell carcinoma (EC) and carcinoma in situ. Our study further investigated the clinical efficacy of TRA-1-60 as a serum tumor marker for germ cell cancer in the testis. Three groups of patients with germ cell tumors were included...... follow-up without having a relapse. Contrary to earlier reports TRA-1-60 is not at present useful as a tumor marker in patients with germ cell tumors. Although detecting a few early relapses the rate of false positive elevations in the tumor marker makes it unreliable in the clinical setting. Our study......: Group 1, 34 patients with disseminated disease (24 nonseminomatous germ cell tumors [NSGCT] and 10 seminomatous germ cell tumors [SGCT]); this group of patients were followed during the course of chemotherapy with measurements of TRA-1-60, HCG and AFP; Group 2, 28 patients with Stage I NSGCT (22...

  2. Two cases report of a malignant germ cell tumour of ovary and a granulosa cell tumour:Interest of tumoral immunochemistry in the identification and management.

    Directory of Open Access Journals (Sweden)

    Jean eBouquet De Jolinière

    2014-05-01

    Full Text Available Abstract Objective: In this article, we present two case reports. The first case was a malignant germ cell tumor of the right ovary in a 23 year old female and a case of a bilateral undifferentiated granulosa cell tumor in a 71 year old female. The aim of these reports is to illustrate the interest of the immuno-histochemical analysis to define the correct diagnosis, to better classify these ovarian tumours and improve their management. Methods: This study we report two cases. The first case concern a 23 years old woman (A with a mixed germ cell tumour of the right ovary (dysgerminoma (75%, yolk sac tumour (20%, and a mature teratoma (5%, and the second case (B a bilateral non differentiated and necrotic granulosa cell tumour of both ovaries concerning a 71 year old patient. The staging system used was according to both classifications, the one of International Federation of Gynaecology and Obstetrics (FIGO 1987 for ovarian cancer, and the one of TNM code 2009. Results: The immunostaining establish the malignancy and the immunochemistry contribute to confirm effectively the right diagnosis (Table 2 and 3. Conclusion: An immuno-histochemical analysis is mandatory for the choice of chemotherapy to obtain the better response of the disease and improve the survival prognosis. The efficiency of the chemotherapy authorizes a conservative surgery including a unilateral salpingo-oophorectomy preserving fertility (A. Concerning the non-dysgerminoma tumour (B, and after a surgical staging and debulking, chemotherapy was recommended. The type of tumour and its histological feature conditioned the choice of treatment. The benefit of the immunohistological analysis in this case allowed the right adjuvant treatment. Key words: germ cell tumours, dysgerminoma, teratoma, yolk sac, ovarian cell tumour, and immunohistochemistry.

  3. Disruption of genital ridge development causes aberrant primordial germ cell proliferation but does not affect their directional migration

    OpenAIRE

    Chen, Su-Ren; Zheng, Qiao-Song; Zhang, Yang; Gao, Fei; Liu, Yi-Xun

    2013-01-01

    Background The directional migration and the following development of primordial germ cells (PGCs) during gonad formation are key steps for germline development. It has been proposed that the interaction between germ cells and genital ridge (GR) somatic cells plays essential roles in this process. However, the in vivo functional requirements of GR somatic cells in germ cell development are largely unknown. Results Wt1 mutation (Wt1 R394W/R394W) results in GR agenesis through mitotic arrest of...

  4. Male Differentiation of Germ Cells Induced by Embryonic Age-Specific Sertoli Cells in Mice1

    Science.gov (United States)

    Ohta, Kohei; Yamamoto, Miyuki; Lin, Yanling; Hogg, Nathanael; Akiyama, Haruhiko; Behringer, Richard R.; Yamazaki, Yukiko

    2012-01-01

    ABSTRACT Retinoic acid (RA) is a meiosis-inducing factor. Primordial germ cells (PGCs) in the developing ovary are exposed to RA, resulting in entry into meiosis. In contrast, PGCs in the developing testis enter mitotic arrest to differentiate into prospermatogonia. Sertoli cells express CYP26B1, an RA-metabolizing enzyme, providing a simple explanation for why XY PGCs do not initiate meios/is. However, regulation of entry into mitotic arrest is likely more complex. To investigate the mechanisms that regulate male germ cell differentiation, we cultured XX and XY germ cells at 11.5 and 12.5 days postcoitus (dpc) with an RA receptor inhibitor. Expression of Stra8, a meiosis initiation gene, was suppressed in all groups. However, expression of Dnmt3l, a male-specific gene, during embryogenesis was elevated but only in 12.5-dpc XY germ cells. This suggests that inhibiting RA signaling is not sufficient for male germ cell differentiation but that the male gonadal environment also contributes to this pathway. To define the influence of Sertoli cells on male germ cell differentiation, Sertoli cells at 12.5, 15.5, and 18.5 dpc were aggregated with 11.5 dpc PGCs, respectively. After culture, PGCs aggregated with 12.5 dpc Sertoli cells increased Nanos2 and Dnmt3l expression. Furthermore, these PGCs established male-specific methylation imprints of the H19 differentially methylated domains. In contrast, PGCs aggregated with Sertoli cells at late embryonic ages did not commit to the male pathway. These findings suggest that male germ cell differentiation is induced both by inhibition of RA signaling and by molecule(s) production by embryonic age-specific Sertoli cells. PMID:22262692

  5. Germ Cell-Specific Excision of loxP-Flanked Transgenes in Rainbow Trout Oncorhynchus mykiss.

    Science.gov (United States)

    Katayama, Naoto; Kume, Sachi; Hattori-Ihara, Shoko; Sadaie, Sakiko; Hayashi, Makoto; Yoshizaki, Goro

    2016-04-01

    Cre/loxP-mediated DNA excision in germ cell lineages could contribute substantially to the study of germ cell biology in salmonids, which are emerging as a model species in this field. However, a cell type-specific Cre/loxPsystem has not been successfully developed for any salmonid species. Therefore, we examined the feasibility of Cre/loxP-mediated, germ cell-specific gene excision and transgene activation in rainbow trout. Double-transgenic (wTg) progeny were obtained by mating a transgenic male carryingcrewith a transgenic female carrying thehsc-LRLGgene;crewas driven by rainbow troutvasaregulatory regions and thehsc-LRLGgene was made up of the rainbow troutheat-shock-cognate71promoter, theDsRedgene flanked by twoloxPsites, and theEgfpgene. PCR analysis, fluorescence imaging, and histological analysis revealed that excision of theloxP-flanked sequence and activation ofEgfpoccurred only in germ cells of wTg fish. However, progeny tests revealed that the excision efficiency ofloxP-flanked sequence in germ cells was low (≤3.27%). In contrast, the other wTg fish derived from two differentcre-transgenic males frequently excised theloxP-flanked sequence in germ cells (≤89.25%). Thus, we showed for the first time successful germ cell-specific transgene manipulation via the Cre/loxPsystem in rainbow trout. We anticipate that this technology will be suitable for studies of cell function through cell targeting, cell-linage tracing, and generating cell type-specific conditional gene knockouts and separately for developing sterile rainbow trout in aquaculture. © 2016 by the Society for the Study of Reproduction, Inc.

  6. Biphasic adaptation to osmotic stress in the C. elegans germ line.

    Science.gov (United States)

    Davis, Michael; Montalbano, Andrea; Wood, Megan P; Schisa, Jennifer A

    2017-06-01

    Cells respond to environmental stress in multiple ways. In the germ line, heat shock and nutritive stress trigger the assembly of large ribonucleoprotein (RNP) granules via liquid-liquid phase separation (LLPS). The RNP granules are hypothesized to maintain the quality of oocytes during stress. The goal of this study was to investigate the cellular response to glucose in the germ line and determine if it is an osmotic stress response. We found that exposure to 500 mM glucose induces the assembly of RNP granules in the germ line within 1 h. Interestingly, the RNP granules are maintained for up to 3 h; however, they dissociate after longer periods of stress. The RNP granules include processing body and stress granule proteins, suggesting shared functions. Based on several lines of evidence, the germ line response to glucose largely appears to be an osmotic stress response, thus identifying osmotic stress as a trigger of LLPS. Although RNP granules are not maintained beyond 3 h of osmotic stress, the quality of oocytes does not appear to decrease after longer periods of stress, suggesting a secondary adaptation in the germ line. We used an indirect marker of glycerol and observed high levels after 5 and 20 h of glucose exposure. Moreover, in gpdh-1;gpdh-2 germ lines, glycerol levels are reduced concomitant with RNP granules being maintained for an extended period. We speculate that increased glycerol levels may function as a secondary osmoregulatory adaptive response in the germ line, following a primary response of RNP granule assembly. Copyright © 2017 the American Physiological Society.

  7. The effects of humanin and its analogues on male germ cell apoptosis induced by chemotherapeutic drugs.

    Science.gov (United States)

    Jia, Yue; Ohanyan, Aikoui; Lue, Yan-He; Swerdloff, Ronald S; Liu, Peter Y; Cohen, Pinchas; Wang, Christina

    2015-04-01

    Human (HN) prevents stress-induced apoptosis in many cells/tissues. In this study we showed that HN ameliorated chemotherapy [cyclophosphamide (CP) and Doxorubicin (DOX)]-induced male germ cell apoptosis both ex vivo in seminiferous tubule cultures and in vivo in the testis. HN acts by several putative mechanisms via binding to: an IL-12 like trimeric membrane receptor; BAX; or insulin-like growth factor binding protein-3 (IGFBP-3, a proapoptotic factor). To understand the mechanisms of HN on male germ cell apoptosis, we studied five HN analogues including: HNG (HN-S14G, a potent agonist), HNG-F6A (no binding to IGFBP-3), HN-S7A (no self-dimerization), HN-C8P (no binding to BAX), and HN-L12A (a HN antagonist) on CP-induced male germ cell apoptosis in mice. CP-induced germ cell apoptosis was inhibited by HN, HNG, HNG-F6A, HN-S7A, and HN-C8P (less effective); but not by HN-L12A. HN-L12A, but not HN-S7A or HN-C8P, blocked the protective effect of HN against CP-induced male germ cell apoptosis. HN, HN-S7A, and HN-C8P restored CP-suppressed STAT3 phosphorylation. These results suggest that HN: (1) decreases DOX (ex vivo) and CP (in vivo) induced male germ cell apoptosis; (2) action is mediated by the membrane receptor/STAT3 with minor contribution by BAX-binding pathway; (3) self-dimerization or binding to IGFBP-3 may not be involved in HN's effect in testis. HN is an important molecule in the regulation of germ cell homeostasis after injury and agonistic analogues may be developed for treating male infertility or protection against chemotherapy side effects.

  8. Glycolipids of human primary testicular germ cell tumours.

    Science.gov (United States)

    Olie, R. A.; Fenderson, B.; Daley, K.; Oosterhuis, J. W.; Murphy, J.; Looijenga, L. H.

    1996-01-01

    The glycolipid content of human non-seminomatous germ cell tumour cell lines correlates with their differentiation lineage. To analyse whether this reflects the situation in primary tumours, we studied five embryonal carcinomas, five yolk sac tumours and nine (mixed) non-seminomas, using thin-layer chromatography and carbohydrate immunostaining. We also analysed the glycolipid content of 19 seminomas to reveal their relationship with non-seminomas. Lactosylceramide (CDH) was detected in all embryonal carcinomas, but in fewer than half of the seminomas. Seminomas and embryonal carcinomas contained globoseries glycolipids, including globotriosylceramide (Gb3), globoside (Gb4), galactosy globoside (Gb5) and sialy1 galactosyl globoside (GL7). The lacto-series glycolipid Le(x) was found in all embryonal carcinomas, but only in one seminoma. Gangliosides GD3 and GT3 were detected in many seminomas, but rarely in embryonal carcinomas. Yolk sac tumours displayed a heterogeneous glycolipid profile. Compared with seminomas and pure embryonal carcinomas, differentiated non-seminomas had reduced levels of globo-series glycolipids, especially Gb3 and Gb5, whereas CDH, Le(x), GD3 and GT3 were found in the majority of cases. Thus, the glycolipid content of non-seminoma cell lines reflects the situation in primary tumours. Globo-series glycolipids are similarly expressed in seminomas and embryonal carcinomas. The expression of Gb3 and Gb5 is reduced in non-seminomas upon differentiation. Le(x) expression in non-seminomas, including embryonal carcinomas, allows discrimination from seminomas. Expression of gangliosides in seminomas might indicate their maturation from ganglioside-negative precursor cells. Reprogramming of these precursors would result in the formation of Le(x)-expressing embryonal carcinomas. Images Figure 1 Figure 2 PMID:8679447

  9. Endogenous DNA Damage and Risk of Testicular Germ Cell Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Cook, M B; Sigurdson, A J; Jones, I M; Thomas, C B; Graubard, B I; Korde, L; Greene, M H; McGlynn, K A

    2008-01-18

    Testicular germ cell tumors (TGCT) are comprised of two histologic groups, seminomas and nonseminomas. We postulated that the possible divergent pathogeneses of these histologies may be partially explained by variable endogenous DNA damage. To assess our hypothesis, we conducted a case-case analysis of seminomas and nonseminomas using the alkaline comet assay to quantify single-strand DNA breaks and alkali-labile sites. The Familial Testicular Cancer study and the U.S. Radiologic Technologists cohort provided 112 TGCT cases (51 seminomas & 61 nonseminomas). A lymphoblastoid cell line was cultured for each patient and the alkaline comet assay was used to determine four parameters: tail DNA, tail length, comet distributed moment (CDM) and Olive tail moment (OTM). Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regression. Values for tail length, tail DNA, CDM and OTM were modeled as categorical variables using the 50th and 75th percentiles of the seminoma group. Tail DNA was significantly associated with nonseminoma compared to seminoma (OR{sub 50th percentile} = 3.31, 95%CI: 1.00, 10.98; OR{sub 75th percentile} = 3.71, 95%CI: 1.04, 13.20; p for trend=0.039). OTM exhibited similar, albeit statistically non-significant, risk estimates (OR{sub 50th percentile} = 2.27, 95%CI: 0.75, 6.87; OR{sub 75th percentile} = 2.40, 95%CI: 0.75, 7.71; p for trend=0.12) whereas tail length and CDM showed no association. In conclusion, the results for tail DNA and OTM indicate that endogenous DNA damage levels are higher in patients who develop nonseminoma compared with seminoma. This may partly explain the more aggressive biology and younger age-of-onset of this histologic subgroup compared with the relatively less aggressive, later-onset seminoma.

  10. Scrotal Involvement with Testicular Nonseminomatous Germ Cell Tumour

    Directory of Open Access Journals (Sweden)

    C. G. O’Leary

    2016-01-01

    Full Text Available A 37-year-old male presented with a traumatic injury to the scrotal region necessitating emergency surgery. Evacuation of a haematoma and bilateral orchidectomy were performed. A left sided nonseminomatous germ cell tumour (NSGCT, predominantly yolk sac, was identified. Microscopic margins were positive for tumour. Initial tumour markers revealed an AFP of 22,854 ng/mL, HCG of <1 mIU/mL, and LDH of 463 IU/L. Eight weeks after surgery, AFP levels remained elevated at 11,646 ng/mL. Computed tomography (CT scanning demonstrated left inguinal adenopathy, 1.5 cm in max dimension. On review, extensive evidence of scrotal involvement was evident. His tumour was staged as stage IIIC, poor risk NSGCT. He was treated with 4 cycles of bleomycin, etoposide, and cisplatin over a 12-week period. His tumour markers normalised after 3 cycles. There was a marked improvement noted clinically. Follow-up CT scans demonstrated complete resolution of his tumour. He later underwent further surgery to remove a small amount of remaining spermatic cord. Histology revealed no malignant tissue. The patient suffered many complications including testosterone deficiency, osteopenia, infertility, and psychological distress. Discussion. A small proportion of testicular cancer may present in an atypical manner. The scrotum and testicle have markedly different embryonic origins and therefore a distinct anatomic separation. As a result the scrotum is not a typical site of spread of testicular cancer. Case reports have been described that were managed in a similar manner with good outcomes. Therefore, even with significant scrotal involvement, if timely and appropriate treatment is administered, complete resolution of the tumour may be achieved.

  11. SEVERO code - user's manual

    International Nuclear Information System (INIS)

    Sacramento, A.M. do.

    1989-01-01

    This user's manual contains all the necessary information concerning the use of SEVERO code. This computer code is related to the statistics of extremes = extreme winds, extreme precipitation and flooding hazard risk analysis. (A.C.A.S.)

  12. Model and code development

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Progress in model and code development for reactor physics calculations is summarized. The codes included CINDER-10, PHROG, RAFFLE GAPP, DCFMR, RELAP/4, PARET, and KENO. Kinetics models for the PBF were developed

  13. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  14. Gender differences in the induction of chromosomal aberrations and gene mutations in rodent germ cells

    International Nuclear Information System (INIS)

    Adler, Ilse-Dore; Carere, Angelo; Eichenlaub-Ritter, Ursula; Pacchierotti, Francesca

    2007-01-01

    Germ cell mutagenicity testing provides experimental data to quantify genetic risk for exposed human populations. The majority of tests are performed with exposure of males, and female data are relatively rare. The reason for this paucity lies in the differences between male and female germ cell biology. Male germ cells are produced throughout reproductive life and all developmental stages can be ascertained by appropriate breeding schemes. In contrast, the female germ cell pool is limited, meiosis begins during embryogenesis and oocytes are arrested over long periods of time until maturation processes start for small numbers of oocytes during the oestrus cycle in mature females. The literature data are reviewed to point out possible gender differences of germ cells to exogenous agents such as chemicals or ionizing radiation. From the limited information, it can be concluded that male germ cells are more sensitive than female germ cells to the induction of chromosomal aberrations and gene mutations. However, exceptions are described which shed doubt on the extrapolation of experimental data from male rodents to the genetic risk of the human population. Furthermore, the female genome may be more sensitive to mutation induction during peri-conceptional stages compared to the male genome of the zygote. With few exceptions, germ cell experiments have been carried out under high acute exposure to optimize the effects and to compensate for the limited sample size in animal experiments. Human exposure to environmental agents, on the other hand, is usually chronic and involves low doses. Under these conditions, gender differences may become apparent that have not been studied so far. Additionally, data are reviewed that suggest a false impression of safety when responses are negative under high acute exposure of male rodents while a mutational response is induced by low chronic exposure. The classical (morphological) germ cell mutation tests are not performed anymore

  15. Enhancing QR Code Security

    OpenAIRE

    Zhang, Linfan; Zheng, Shuang

    2015-01-01

    Quick Response code opens possibility to convey data in a unique way yet insufficient prevention and protection might lead into QR code being exploited on behalf of attackers. This thesis starts by presenting a general introduction of background and stating two problems regarding QR code security, which followed by a comprehensive research on both QR code itself and related issues. From the research a solution taking advantages of cloud and cryptography together with an implementation come af...

  16. Stylize Aesthetic QR Code

    OpenAIRE

    Xu, Mingliang; Su, Hao; Li, Yafei; Li, Xi; Liao, Jing; Niu, Jianwei; Lv, Pei; Zhou, Bing

    2018-01-01

    With the continued proliferation of smart mobile devices, Quick Response (QR) code has become one of the most-used types of two-dimensional code in the world. Aiming at beautifying the appearance of QR codes, existing works have developed a series of techniques to make the QR code more visual-pleasant. However, these works still leave much to be desired, such as visual diversity, aesthetic quality, flexibility, universal property, and robustness. To address these issues, in this paper, we pro...

  17. Toll-like receptor 11-initiated innate immune response in male mouse germ cells.

    Science.gov (United States)

    Chen, Qiaoyuan; Zhu, Weiwei; Liu, Zhenghui; Yan, Keqin; Zhao, Shutao; Han, Daishu

    2014-02-01

    Toxoplasma gondii and uropathogenic Escherichia coli (UPEC) may infect the testis and impair testicular function. Mechanisms underlying testicular innate immune response to these two pathogens remain to be clarified. The present study examined the function of TLR11, which can be recognized by T. gondii-derived profilin and UPEC, in initiating innate immune response in male mouse germ cells. TLR11 is predominantly expressed in spermatids. Profilin and UPEC induced the expressions of different inflammatory cytokine profiles in the germ cells. In particular, profilin induced the expressions of macrophage chemotactic protein 1 (MCP1), interleukin 12 (IL12), and interferon gamma (IFNG) through nuclear factor KB (NFKB) activation. UPEC induced the expressions of MCP1, IL12, and IFNG, as well as tumor necrosis factor alpha (TNFA), IL6, and IFNB, through the activation of NFKB, IFN regulatory factor 3, and mitogen-activated protein kinases. Evidence showed that profilin induced the innate response in male germ cells through TLR11 signaling, and UPEC triggered the response through TLR11 and other TLR-signaling pathways. We also provided evidence that local injection of profilin or UPEC induces the innate immune response in the germ cells. Data describe TLR11-mediated innate immune function of male germ cells in response to T. gondii profilin and UPEC stimulations. This system may play a role in testicular defense against T. gondii and UPEC infections in mice.

  18. Soy Germ Protein With or Without-Zn Improve Plasma Lipid Profile in Metabolic Syndrome Women

    Directory of Open Access Journals (Sweden)

    HERY WINARSI

    2012-03-01

    Full Text Available The aim of this research was to determine the effect of soy germ protein on lipid profile of metabolic syndrome (MetS patients. Respondents were 30 women with criteria, i.e. blood glucose level > normal, body mass index > 25 kg/m2, hypertriglyceridemia, low cholesterol-HDL level, 40-65 years old, living in Purwokerto, and signed the informed consent. The project was approved by the ethics committee of the Medical Faculty from Gadjah Mada University-Yogyakarta. Respondents were divided into three randomly chosen groups consisting of ten women each. The first, second, and third groups were treated, respectively, with milk enriched soy germ protein plus Zn, milk enriched soy germ protein (without Zn, and placebo for two months. Blood samples were taken at baseline, one and two months after observation. Two months after observation the groups consuming milk enriched with soy germ protein, both with or without Zn, had their level of cholesterol-total decrease from 215.8 to 180.2 mg/dl (P = 0.03, triglyceride from 240.2 to 162.5 mg/dl (P = 0.02, and LDL from 154.01 to 93.85 mg/dl (P = 0.03. In contrast, HDL increased from 38.91 to 49.49 mg/dl (P = 0.0008. In conclusion, soy germ protein can improve lipid profile, thus it can inhibit atherosclerosis incident.

  19. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling.

    Science.gov (United States)

    Hu, Yueh-Chiang; Nicholls, Peter K; Soh, Y Q Shirleen; Daniele, Joseph R; Junker, Jan Philipp; van Oudenaarden, Alexander; Page, David C

    2015-03-01

    In mouse embryos at mid-gestation, primordial germ cells (PGCs) undergo licensing to become gametogenesis-competent cells (GCCs), gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO) mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge.

  20. Tdrd12 Is Essential for Germ Cell Development and Maintenance in Zebrafish

    Directory of Open Access Journals (Sweden)

    Xiangyan Dai

    2017-06-01

    Full Text Available The regularity of Piwi-interacting RNA (piRNA biogenesis is crucial to germline development. Functioning as Piwi-interacting proteins, Tudor domain-related proteins (Tdrds have been demonstrated to be involved in spermatogenesis and the piRNA pathway. In this study, zebrafish tdrd12 was identified, and the maternal and germ cell-specific expression patterns of zebrafish tdrd12 were observed. Utilizing TALEN (transcription activator-like effector nuclease techniques, two independent tdrd12 mutant zebrafish lines were generated. Although no defects were found during the generation of the primordial germ cells (PGCs in the tdrd12-null fish progenies obtained from the heterozygous tdrd12 mutant parents, all Tdrd12-deficient fish developed into infertile males. The reduced numbers and eventually loss of the germ cells by 35 days post fertilization (dpf led to masculinization and infertility of the Tdrd12-deficient fish. Meiosis defects of the germ cells in the tdrd12 mutants during the gonad-transitioning period were observed, revealing the indispensable functions of Tdrd12 in gametogenesis. Our studies demonstrated that zebrafish Tdrd12 is essential for germ cell development and maintenance.

  1. Ovarian mixed germ cell tumor with yolk sac and teratomatous components in a dog.

    Science.gov (United States)

    Robinson, Nicholas A; Manivel, J Carlos; Olson, Erik J

    2013-05-01

    Mixed germ cell tumors of the ovary have rarely been reported in veterinary species. A 3-year-old intact female Labrador Retriever dog was presented for lethargy, abdominal distention, and a midabdominal mass. An exploratory laparotomy revealed a large (23 cm in diameter) left ovarian tumor and multiple small (2-3 cm in diameter) pale tan masses on the peritoneum and abdominal surface of the diaphragm. Histological examination of the left ovary revealed a mixed germ cell tumor with a yolk sac component with rare Schiller-Duval bodies and a teratomatous component comprised primarily of neural differentiation. The abdominal metastases were solely comprised of the yolk sac component. The yolk sac component was diffusely immunopositive for cytokeratin with scattered cells reactive for α-fetoprotein and placental alkaline phosphatase. Within the teratomatous component, the neuropil was diffusely immunopositive for S100, neuron-specific enolase, and neurofilaments with a few glial fibrillary acidic protein immunopositive cells. Ovarian germ cell tumors may be pure and consist of only 1 germ cell element or may be mixed and include more than 1 germ cell element, such as teratoma and yolk sac tumor.

  2. Regulation of blood-testis barrier assembly in vivo by germ cells.

    Science.gov (United States)

    Li, Xiao-Yu; Zhang, Yan; Wang, Xiu-Xia; Jin, Cheng; Wang, Yu-Qian; Sun, Tie-Cheng; Li, Jian; Tang, Ji-Xin; Batool, Alia; Deng, Shou-Long; Chen, Su-Ren; Cheng, C Yan; Liu, Yi-Xun

    2018-01-03

    The assembly of the blood-testis barrier (BTB) during postnatal development is crucial to support meiosis. However, the role of germ cells in BTB assembly remains unclear. Herein, Kit W /Kit WV mice were used as a study model. These mice were infertile, failing to establish a functional BTB to support meiosis due to c-Kit mutation. Transplantation of undifferentiated spermatogonia derived from normal mice into the testis of Kit W /Kit WV mice triggered functional BTB assembly, displaying cyclic remodeling during the epithelial cycle. Also, transplanted germ cells were capable of inducing Leydig cell testosterone production, which could enhance the expression of integral membrane protein claudin 3 in Sertoli cells. Early spermatocytes were shown to play a vital role in directing BTB assembly by expressing claudin 3, which likely created a transient adhesion structure to mediate BTB and cytoskeleton assembly in adjacent Sertoli cells. In summary, the positive modulation of germ cells on somatic cell function provides useful information regarding somatic-germ cell interactions.-Li, X.-Y., Zhang, Y., Wang, X.-X., Jin, C., Wang, Y.-Q., Sun, T.-C., Li, J., Tang, J.-X., Batool, A., Deng, S.-L., Chen, S.-R., Cheng, C. Y., Liu, Y.-X. Regulation of blood-testis barrier assembly in vivo by germ cells.

  3. Licensing of primordial germ cells for gametogenesis depends on genital ridge signaling.

    Directory of Open Access Journals (Sweden)

    Yueh-Chiang Hu

    2015-03-01

    Full Text Available In mouse embryos at mid-gestation, primordial germ cells (PGCs undergo licensing to become gametogenesis-competent cells (GCCs, gaining the capacity for meiotic initiation and sexual differentiation. GCCs then initiate either oogenesis or spermatogenesis in response to gonadal cues. Germ cell licensing has been considered to be a cell-autonomous and gonad-independent event, based on observations that some PGCs, having migrated not to the gonad but to the adrenal gland, nonetheless enter meiosis in a time frame parallel to ovarian germ cells -- and do so regardless of the sex of the embryo. Here we test the hypothesis that germ cell licensing is cell-autonomous by examining the fate of PGCs in Gata4 conditional mutant (Gata4 cKO mouse embryos. Gata4, which is expressed only in somatic cells, is known to be required for genital ridge initiation. PGCs in Gata4 cKO mutants migrated to the area where the genital ridge, the precursor of the gonad, would ordinarily be formed. However, these germ cells did not undergo licensing and instead retained characteristics of PGCs. Our results indicate that licensing is not purely cell-autonomous but is induced by the somatic genital ridge.

  4. TOPAZ1, a novel germ cell-specific expressed gene conserved during evolution across vertebrates.

    Directory of Open Access Journals (Sweden)

    Adrienne Baillet

    Full Text Available BACKGROUND: We had previously reported that the Suppression Subtractive Hybridization (SSH approach was relevant for the isolation of new mammalian genes involved in oogenesis and early follicle development. Some of these transcripts might be potential new oocyte and granulosa cell markers. We have now characterized one of them, named TOPAZ1 for the Testis and Ovary-specific PAZ domain gene. PRINCIPAL FINDINGS: Sheep and mouse TOPAZ1 mRNA have 4,803 bp and 4,962 bp open reading frames (20 exons, respectively, and encode putative TOPAZ1 proteins containing 1,600 and 1653 amino acids. They possess PAZ and CCCH domains. In sheep, TOPAZ1 mRNA is preferentially expressed in females during fetal life with a peak during prophase I of meiosis, and in males during adulthood. In the mouse, Topaz1 is a germ cell-specific gene. TOPAZ1 protein is highly conserved in vertebrates and specifically expressed in mouse and sheep gonads. It is localized in the cytoplasm of germ cells from the sheep fetal ovary and mouse adult testis. CONCLUSIONS: We have identified a novel PAZ-domain protein that is abundantly expressed in the gonads during germ cell meiosis. The expression pattern of TOPAZ1, and its high degree of conservation, suggests that it may play an important role in germ cell development. Further characterization of TOPAZ1 may elucidate the mechanisms involved in gametogenesis, and particularly in the RNA silencing process in the germ line.

  5. ARC Code TI: CODE Software Framework

    Data.gov (United States)

    National Aeronautics and Space Administration — CODE is a software framework for control and observation in distributed environments. The basic functionality of the framework allows a user to observe a distributed...

  6. ARC Code TI: ROC Curve Code Augmentation

    Data.gov (United States)

    National Aeronautics and Space Administration — ROC (Receiver Operating Characteristic) curve Code Augmentation was written by Rodney Martin and John Stutz at NASA Ames Research Center and is a modification of ROC...

  7. Refactoring test code

    NARCIS (Netherlands)

    A. van Deursen (Arie); L.M.F. Moonen (Leon); A. van den Bergh; G. Kok

    2001-01-01

    textabstractTwo key aspects of extreme programming (XP) are unit testing and merciless refactoring. Given the fact that the ideal test code / production code ratio approaches 1:1, it is not surprising that unit tests are being refactored. We found that refactoring test code is different from

  8. Error Correcting Codes -34 ...

    Indian Academy of Sciences (India)

    the reading of data from memory the receiving process. Protecting data in computer memories was one of the earliest applications of Hamming codes. We now describe the clever scheme invented by Hamming in 1948. To keep things simple, we describe the binary length 7 Hamming code. Encoding in the Hamming Code.

  9. Morse Code Activity Packet.

    Science.gov (United States)

    Clinton, Janeen S.

    This activity packet offers simple directions for setting up a Morse Code system appropriate to interfacing with any of several personal computer systems. Worksheets are also included to facilitate teaching Morse Code to persons with visual or other disabilities including blindness, as it is argued that the code is best learned auditorily. (PB)

  10. Software Certification - Coding, Code, and Coders

    Science.gov (United States)

    Havelund, Klaus; Holzmann, Gerard J.

    2011-01-01

    We describe a certification approach for software development that has been adopted at our organization. JPL develops robotic spacecraft for the exploration of the solar system. The flight software that controls these spacecraft is considered to be mission critical. We argue that the goal of a software certification process cannot be the development of "perfect" software, i.e., software that can be formally proven to be correct under all imaginable and unimaginable circumstances. More realistically, the goal is to guarantee a software development process that is conducted by knowledgeable engineers, who follow generally accepted procedures to control known risks, while meeting agreed upon standards of workmanship. We target three specific issues that must be addressed in such a certification procedure: the coding process, the code that is developed, and the skills of the coders. The coding process is driven by standards (e.g., a coding standard) and tools. The code is mechanically checked against the standard with the help of state-of-the-art static source code analyzers. The coders, finally, are certified in on-site training courses that include formal exams.

  11. The network code

    International Nuclear Information System (INIS)

    1997-01-01

    The Network Code defines the rights and responsibilities of all users of the natural gas transportation system in the liberalised gas industry in the United Kingdom. This report describes the operation of the Code, what it means, how it works and its implications for the various participants in the industry. The topics covered are: development of the competitive gas market in the UK; key points in the Code; gas transportation charging; impact of the Code on producers upstream; impact on shippers; gas storage; supply point administration; impact of the Code on end users; the future. (20 tables; 33 figures) (UK)

  12. The materiality of Code

    DEFF Research Database (Denmark)

    Soon, Winnie

    2014-01-01

    , Twitter and Facebook). The focus is not to investigate the functionalities and efficiencies of the code, but to study and interpret the program level of code in order to trace the use of various technological methods such as third-party libraries and platforms’ interfaces. These are important...... to understand the socio-technical side of a changing network environment. Through the study of code, including but not limited to source code, technical specifications and other materials in relation to the artwork production, I would like to explore the materiality of code that goes beyond technical...

  13. Coding for Electronic Mail

    Science.gov (United States)

    Rice, R. F.; Lee, J. J.

    1986-01-01

    Scheme for coding facsimile messages promises to reduce data transmission requirements to one-tenth current level. Coding scheme paves way for true electronic mail in which handwritten, typed, or printed messages or diagrams sent virtually instantaneously - between buildings or between continents. Scheme, called Universal System for Efficient Electronic Mail (USEEM), uses unsupervised character recognition and adaptive noiseless coding of text. Image quality of resulting delivered messages improved over messages transmitted by conventional coding. Coding scheme compatible with direct-entry electronic mail as well as facsimile reproduction. Text transmitted in this scheme automatically translated to word-processor form.

  14. XSOR codes users manual

    International Nuclear Information System (INIS)

    Jow, Hong-Nian; Murfin, W.B.; Johnson, J.D.

    1993-11-01

    This report describes the source term estimation codes, XSORs. The codes are written for three pressurized water reactors (Surry, Sequoyah, and Zion) and two boiling water reactors (Peach Bottom and Grand Gulf). The ensemble of codes has been named ''XSOR''. The purpose of XSOR codes is to estimate the source terms which would be released to the atmosphere in severe accidents. A source term includes the release fractions of several radionuclide groups, the timing and duration of releases, the rates of energy release, and the elevation of releases. The codes have been developed by Sandia National Laboratories for the US Nuclear Regulatory Commission (NRC) in support of the NUREG-1150 program. The XSOR codes are fast running parametric codes and are used as surrogates for detailed mechanistic codes. The XSOR codes also provide the capability to explore the phenomena and their uncertainty which are not currently modeled by the mechanistic codes. The uncertainty distributions of input parameters may be used by an. XSOR code to estimate the uncertainty of source terms

  15. Cigarette smoking during early pregnancy reduces the number of embryonic germ and somatic cells

    DEFF Research Database (Denmark)

    Mamsen, Linn; Lutterodt, M C; Andersen, Elisabeth Anne Wreford

    2010-01-01

    BACKGROUND: Cigarette smoking during pregnancy is associated with negative reproductive consequences for male fetuses in adult life such as reduced testicular volume and sperm concentration. The present study evaluates the number of germ and somatic cells present in human embryonic first...... stereological methods were used to estimate gonadal cell numbers in histological sections. Results were also evaluated in the context of previously published data on ovaries from our laboratory. RESULTS: A significant reduction in the number of germ cells by 55% [95% confidence interval (CI) 74-21% reduction, P...... confounders such as alcohol and coffee consumption (P = 0.002). The number of germ cells in embryonic gonads, irrespective of gender, was also significantly reduced by 41% (95% CI 58-19%, P = 0.001) in exposed versus non-exposed embryonic gonads. CONCLUSIONS: Prenatal exposure to maternal cigarette smoke...

  16. Involvement of the DNA mismatch repair system in cisplatin sensitivity of testicular germ cell tumours

    DEFF Research Database (Denmark)

    Rudolph, Christiane; Melau, Cecilie; Nielsen, John E.

    2017-01-01

    BackgroundTesticular germ cell tumours (TGCT) are highly sensitive to cisplatin-based chemotherapy, but patients with tumours containing differentiated teratoma components are less responsive to this treatment. The cisplatin sensitivity in TGCT has previously been linked to the embryonic phenotype......, were investigated during testis development and in the pathogenesis of TGCT, including germ cell neoplasia in situ (GCNIS). The TGCT-derived cell line NTera2 was differentiated using retinoic acid (10 μM, 6 days) after which MMR protein expression and activity, as well as cisplatin sensitivity, were...... investigated in both undifferentiated and differentiated cells. Finally, the expression of MSH2 was knocked down by siRNA in NTera2 cells after which the effect on cisplatin sensitivity was examined. ResultsMMR proteins were expressed in proliferating cells in the testes, while in malignant germ cells MMR...

  17. Origin of pluripotent germ cell tumours: the role of microenvironment during embryonic development

    DEFF Research Database (Denmark)

    Kristensen, David Møbjerg; Sonne, Si Brask; Ottesen, Anne Marie

    2008-01-01

    has recently been explained by a close resemblance of their expression profile to that of embryonic inner cell mass cells studied in culture as embryonic stem cells, with high expression of transcription factors associated with pluripotency, such as NANOG and OCT3/4, as well as proteins found...... in several tissue specific stem cells, such as TFAP2C (AP-2gamma) or KIT. CIS and seminomas highly express a number of pre-meiotic germ cell specific genes, which are down-regulated during development to non-seminomas, while the expression of other embryonic markers, such as SOX2, is up......Carcinoma in situ (CIS) testis, known also as intratubular germ cell neoplasia, is the cancer stem cell from which the great majority of testicular germ cell derived tumours (TGCTs) of the testis arise. TGCTs can proliferate into morphologically homogeneous seminomas or can differentiate...

  18. Treatment-related cardiovascular late effects and exercise training countermeasures in testicular germ cell cancer survivorship

    DEFF Research Database (Denmark)

    Christensen, Jesper F; Bandak, Mikkel; Campbell, Anna

    2015-01-01

    , are subjected to toxicities, which individually, and synergistically, can cause physiological impairments leading to sub-clinical or clinical cardiovascular disorders (i.e. the 'multiple-hit hypothesis'). Furthermore, we discuss the efficacy and utility of structured exercise training to ameliorate treatment......-induced cardiovascular dysfunction to prevent premature onset of clinical cardiovascular disease in germ cell cancer survivors, with a view towards highlighting future directions of exercise-based survivorship research in the germ cell cancer setting. CONCLUSION: As exercise training may have the potential to ameliorate....... However, the excellent cancer-specific survival comes at considerable costs, as individuals with a history of germ cell cancer experience serious long-term complications, including markedly increased risk of cardiovascular morbidities and premature cardiovascular death. The factors responsible, as well...

  19. Metastable primordial germ cell-like state induced from mouse embryonic stem cells by Akt activation

    Energy Technology Data Exchange (ETDEWEB)

    Yamano, Noriko [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Kimura, Tohru, E-mail: tkimura@patho.med.osaka-u.ac.jp [Department of Pathology, Medical School, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Watanabe-Kushima, Shoko [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Shinohara, Takashi [Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501 (Japan); Nakano, Toru, E-mail: tnakano@patho.med.osaka-u.ac.jp [Graduate School of Frontier Biosciences, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan); Department of Pathology, Medical School, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2010-02-12

    Specification to primordial germ cells (PGCs) is mediated by mesoderm-induction signals during gastrulation. We found that Akt activation during in vitro mesodermal differentiation of embryonic stem cells (ESCs) generated self-renewing spheres with differentiation states between those of ESCs and PGCs. Essential regulators for PGC specification and their downstream germ cell-specific genes were expressed in the spheres, indicating that the sphere cells had commenced differentiation to the germ lineage. However, the spheres did not proceed to spermatogenesis after transplantation into testes. Sphere cell transfer to the original feeder-free ESC cultures resulted in chaotic differentiation. In contrast, when the spheres were cultured on mouse embryonic fibroblasts or in the presence of ERK-cascade and GSK3 inhibitors, reversion to the ESC-like state was observed. These results indicate that Akt signaling promotes a novel metastable and pluripotent state that is intermediate to those of ESCs and PGCs.

  20. Efficient TALEN-mediated gene targeting of chicken primordial germ cells.

    Science.gov (United States)

    Taylor, Lorna; Carlson, Daniel F; Nandi, Sunil; Sherman, Adrian; Fahrenkrug, Scott C; McGrew, Michael J

    2017-03-01

    In this work we use TALE nucleases (TALENs) to target a reporter construct to the DDX4 ( vasa ) locus in chicken primordial germ cells (PGCs). Vasa is a key germ cell determinant in many animal species and is posited to control avian germ cell formation. We show that TALENs mediate homology-directed repair of the DDX4 locus on the Z sex chromosome at high (8.1%) efficiencies. Large genetic deletions of 30 kb encompassing the entire DDX4 locus were also created using a single TALEN pair. The targeted PGCs were germline competent and were used to produce DDX4 null offspring. In DDX4 knockout chickens, PGCs are initially formed but are lost during meiosis in the developing ovary, leading to adult female sterility. TALEN-mediated gene targeting in avian PGCs is therefore an efficient process. © 2017. Published by The Company of Biologists Ltd.

  1. Heterozygosity for a Bub1 mutation causes female-specific germ cell aneuploidy in mice

    Energy Technology Data Exchange (ETDEWEB)

    Leland, Shawn; Nagarajan, Prabakaran; Polyzos, Aris; Thomas, Sharon; Samaan, George; Donnell, Robert; Marchetti, Francesco; Venkatachalam, Sundaresan

    2009-06-24

    Aneuploidy, the most common chromosomal abnormality at birth and the main ascertained cause of pregnancy loss in humans, originates primarily from chromosome segregation errors during oogenesis. Here we report that heterozygosity for a mutation in the mitotic checkpoint kinase gene, Bub1, induces aneuploidy in female germ cells of mice, and that the effect increases with advancing maternal age. Analysis of Bub1 heterozygous oocytes showed that aneuploidy occurred primarily during the first meiotic division and involved premature sister chromatid separation. Furthermore, aneuploidy was inherited in zygotes and resulted in the loss of embryos after implantation. The incidence of aneuploidy in zygotes was sufficient to explain the reduced litter size in matings with Bub1 heterozygous females. No effects were seen in germ cells from heterozygous males. These findings show that Bub1 dysfunction is linked to inherited aneuploidy in female germ cells and may contribute to the maternal age-related increase in aneuploidy and pregnancy loss.

  2. Primordial germ cell biology at the beginning of the XXI century.

    Science.gov (United States)

    De Felici, Massimo

    2009-01-01

    At the XIV Workshop on the Development and Function of the Reproductive Organs held at the Congress Centre of the University of Rome Tor Vergata, Monteporzio Catone, Rome, Italy, the introduction to the first session entitled Mammalian primordial germ cells dedicated to the memory of Anne McLaren, was the occasion for a concise review of the state of art of research on the biology of primordial germ cells (PGCs). This great, unforgettable scientist, who died in a car accident in July 2007, dedicated most of her studies to this field over the last 25 years. Topics briefly reviewed in this Meeting Report are: 1) how the germ line is determined; 2) what are the mechanisms underlying PGC migration; 3) to what extent PGC survival, proliferation and differentiation are cell autonomous or environmentally controlled processes and 4) how the potential for totipotency is retained in PGCs.

  3. An ABC transporter controls export of a Drosophila germ cell attractant.

    Science.gov (United States)

    Ricardo, Sara; Lehmann, Ruth

    2009-02-13

    Directed cell migration, which is critical for embryonic development, leukocyte trafficking, and cell metastasis, depends on chemoattraction. 3-hydroxy-3-methylglutaryl coenzyme A reductase regulates the production of an attractant for Drosophila germ cells that may itself be geranylated. Chemoattractants are commonly secreted through a classical, signal peptide-dependent pathway, but a geranyl-modified attractant would require an alternative pathway. In budding yeast, pheromones produced by a-cells are farnesylated and secreted in a signal peptide-independent manner, requiring the adenosine triphosphate-binding cassette (ABC) transporter Ste6p. Here we show that Drosophila germ cell migration uses a similar pathway, demonstrating that invertebrate germ cells, like yeast cells, are attracted to lipid-modified peptides. Components of this unconventional export pathway are highly conserved, suggesting that this pathway may control the production of similarly modified chemoattractants in organisms ranging from yeast to humans.

  4. MULTIFOCAL CHOROIDAL MELANOMA IN A PATIENT WITH GERM LINE BRCA-ASSOCIATED PROTEIN 1 MUTATION.

    Science.gov (United States)

    Rao, Raksha; Pointdujour-Lim, Renelle; Ganguly, Arupa; Shields, Carol L

    2018-01-01

    To report a case of unilateral multifocal melanoma in a patient with germ line BRCA-associated protein 1 mutation. Case report. A 67-year-old white woman with a family history of lung and liver cancers developed blurred visual acuity of 20/30 in the left eye. She was discovered to have two independent pigmented choroidal melanomas in the macula and superotemporally, both demonstrating overlying subretinal fluid and orange pigment. Both melanomas were treated with a single custom-designed Iodine 125 brachytherapy device. Upon systemic evaluation, asymptomatic renal cell carcinoma was found, and blood lymphocyte testing for germ line BRCA-associated protein 1 mutation was positive. Multifocal choroidal melanoma is exceedingly rare. Patients with uveal melanoma, especially if multifocal, and those with other systemic malignancy or family history of cancers should be tested for germ line BRCA-associated protein 1 mutation. Lifelong monitoring for other systemic malignancies is advised.

  5. Dnd Is a Critical Specifier of Primordial Germ Cells in the Medaka Fish

    Directory of Open Access Journals (Sweden)

    Ni Hong

    2016-03-01

    Full Text Available Primordial germ cell (PGC specification occurs early in development. PGC specifiers have been identified in Drosophila, mouse, and human but remained elusive in most animals. Here we identify the RNA-binding protein Dnd as a critical PGC specifier in the medaka fish (Oryzias latipes. Dnd depletion specifically abolished PGCs, and its overexpression boosted PGCs. We established a single-cell culture procedure enabling lineage tracing in vitro. We show that individual blastomeres from cleavage embryos at the 32- and 64-cell stages are capable of PGC production in culture. Importantly, Dnd overexpression increases PGCs via increasing PGC precursors. Strikingly, dnd RNA forms prominent particles that segregate asymmetrically. Dnd concentrates in germ plasm and stabilizes germ plasm RNA. Therefore, Dnd is a critical specifier of fish PGCs and utilizes particle partition as a previously unidentified mechanism for asymmetric segregation. These findings offer insights into PGC specification and manipulation in medaka as a lower vertebrate model.

  6. Erythropoietin may reduce the risk of germ cell loss in boys with cryptorchidism

    DEFF Research Database (Denmark)

    Cortes, D; Visfeldt, J; Thorup, J M

    2001-01-01

    of infertility. In order to increase the number of germ cells, and thereby the fertility potential, additional hormonal therapy has been attempted before surgery. In a study, small doses of the gonadotropin-releasing hormone analogue buserelin before orchiopexy caused higher values. Others have found......: Erythropoietin (Eprex) 100 IU/kg were administered subcutaneously weekly for 3 months prior to surgery in two cryptorchid boys, 6 months old and 1 year 9 months old, respectively, with renal function impairment. RESULTS: The number of spermatogonia per tubular cross-section in testicular biopsies was unusually...... that hormonal treatment with human chorionic gonadotropin or gonadotropin releasing hormone analogue may harm the germ cells in cryptorchidism. The aim of the study is to demonstrate that additional hormonal therapy with erythropoietin has a positive effect on the number of germ cells. MATERIALS AND METHODS...

  7. DLLExternalCode

    Energy Technology Data Exchange (ETDEWEB)

    2014-05-14

    DLLExternalCode is the a general dynamic-link library (DLL) interface for linking GoldSim (www.goldsim.com) with external codes. The overall concept is to use GoldSim as top level modeling software with interfaces to external codes for specific calculations. The DLLExternalCode DLL that performs the linking function is designed to take a list of code inputs from GoldSim, create an input file for the external application, run the external code, and return a list of outputs, read from files created by the external application, back to GoldSim. Instructions for creating the input file, running the external code, and reading the output are contained in an instructions file that is read and interpreted by the DLL.

  8. Doubly uniparental inheritance of mitochondria as a model system for studying germ line formation.

    Directory of Open Access Journals (Sweden)

    Liliana Milani

    Full Text Available BACKGROUND: Doubly Uniparental Inheritance (DUI of mitochondria occurs when both mothers and fathers are capable of transmitting mitochondria to their offspring, in contrast to the typical Strictly Maternal Inheritance (SMI. DUI was found in some bivalve molluscs, in which two mitochondrial genomes are inherited, one through eggs, the other through sperm. During male embryo development, spermatozoon mitochondria aggregate in proximity of the first cleavage furrow and end up in the primordial germ cells, while they are dispersed in female embryos. METHODOLOGY/PRINCIPAL FINDINGS: We used MitoTracker, microtubule staining and transmission electron microscopy to examine the mechanisms of this unusual distribution of sperm mitochondria in the DUI species Ruditapes philippinarum. Our results suggest that in male embryos the midbody deriving from the mitotic spindle of the first division concurs in positioning the aggregate of sperm mitochondria. Furthermore, an immunocytochemical analysis showed that the germ line determinant Vasa segregates close to the first cleavage furrow. CONCLUSIONS/SIGNIFICANCE: In DUI male embryos, spermatozoon mitochondria aggregate in a stable area on the animal-vegetal axis: in organisms with spiral segmentation this zone is not involved in cleavage, so the aggregation is maintained. Moreover, sperm mitochondria reach the same embryonic area in which also germ plasm is transferred. In 2-blastomere embryos, the segregation of sperm mitochondria in the same region with Vasa suggests their contribution in male germ line formation. In DUI male embryos, M-type mitochondria must be recognized by egg factors to be actively transferred in the germ line, where they become dominant replacing the Balbiani body mitochondria. The typical features of germ line assembly point to a common biological mechanism shared by DUI and SMI organisms. Although the molecular dynamics of the segregation of sperm mitochondria in DUI species are unknown

  9. Chemical composition and metabolizable energy values of corn germ meal obtained by wet milling for layers

    Directory of Open Access Journals (Sweden)

    CS Albuquerque

    2014-03-01

    Full Text Available An experiment was carried out to determine the chemical composition, metabolizable energy values, and coefficients of nutrient digestibility of corn germ meal for layers. The chemical composition of corn germ meal was determined, and then a metabolism assay was performed to determine its apparent metabolizable energy (AME and apparent metabolizable energy corrected for nitrogen (AMEn values and its dry matter and gross energy apparent metabolizability coefficients (CAMDM and CAMGE, respectively. In the 8-day assay (four days of adaptation and four days of total excreta collection, 60 29-week-old white Lohman LSL layers were used. A completely randomized experimental design, with three treatments with five replicates of four birds each, was applied. Treatments consisted of a reference diet and two test diets, containing 20 or 30% corn germ meal. Results were submitted to analysis of variance and means were compared by the Tukey tests at 5% probability level. The chemical composition of corn germ meal was: 96.39% dry matter, 49.48% ether extract, 1.87% ashes, 7243 kcal gross energy/kg, 11.48% protein, 0.19% methionine, 0.21% cystine, 0.48% lysine, 0.40% threonine, 0.72% arginine, 0.35% isoleucine, 0.83% leucine, 0.57% valine, and 0.37% histidine, on as-fed basis. There were no statistical differences in AME, AMEn, CAMDM, and CAMGE values with the inclusion of 20 and 30% corn germ meal in the diets. On dry matter basis, AME, AMEn, CAMDM, and CAMGE values of corn germ meal were: 4,578 and 4,548 kcal/kg, 4,723 and 4,372 kcal/kg, 64.95 and 61.86%, respectively.

  10. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

    International Nuclear Information System (INIS)

    Kheradmand, Arash; Dezfoulian, Omid; Alirezaei, Masoud; Rasoulian, Bahram

    2012-01-01

    Highlights: ► Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. ► Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. ► Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. ► Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P 0.05). Upstream of Bax substance parallel to down-regulation of PCNA demonstrate that ghrelin may prevent massive accumulation of germ cells during normal spermatogenesis. These observations also indicate that ghrelin may be considered as a modulator of spermatogenesis in normal adult rats and could be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors.

  11. Sufficient numbers of early germ cells are essential for female sex development in zebrafish.

    Directory of Open Access Journals (Sweden)

    Xiangyan Dai

    Full Text Available The sex determination for zebrafish is controlled by a combination of genetic and environmental factors. The determination of sex in zebrafish has been suggested to rely on a mechanism that is affected by germ cell-derived signals. To begin our current study, a simplified and efficient germ cell-specific promoter of the dead end (dnd gene was identified. Utilizing the metrodinazole (MTZ/ bacterial nitroreductase (NTR system for inducible germ cell ablation, several stable Tg (dnd:NTR-EGFP(-3'UTR and Tg (dnd:NTR-EGFP(+3'UTR zebrafish lines were then generated with the identified promoter. A thorough comparison of the expression patterns and tissue distributions of endogenous dnd and ntr-egfp transcripts in vivo revealed that the identified 2032-bp zebrafish dnd promoter can recapitulate dnd expression faithfully in stable transgenic zebrafish. The correlation between the levels of the germ cell-derived signals and requirement for maintaining the female fate has been also explored with different durations of the MTZ treatments. Our results revealed the decreasing ratios of female presented in the treated transgenic group are fairly associated with the reducing levels of the early germ cell-derived signals. After the juvenile transgenic fish treated with 5 mM MTZ for 20 days, all MTZ-treated transgenic fish exclusively developed into males with subfertilities. Taken together, our results identified here a simplified and efficient dnd promoter, and provide clear evidence indicating that it was not the presence but the sufficiency of signals derived from germ cells that is essential for female sex development in zebrafish. Our model also provides a unique system for sex control in zebrafish studies.

  12. Tissue Specific Roles of Dynein Light Chain 1 in Regulating Germ Cell Apoptosis in Ceanorhabditis elegans

    DEFF Research Database (Denmark)

    Morthorst, Tine Hørning

    2015-01-01

    physiological apoptosis inside the dying germ cells through a dynein-dependent pathway. DLC-1 and dynein heavy chain (DHC-1) localizes to the nuclear membrane of apoptotic germ cells, and depletion of either one inhibits the induction of physiological apoptosis, but not damage induced apoptosis. Their pro......-apoptotic function seems to be dependent on a functional engulfment machinery, as depletion of dlc-1 or dhc-1 only affects apoptosis in engulfment defective mutants. Lastly, DLC-1 was found to affect the localization of the engulfment receptor CED-1, probably by mediating the activity of clathrin mediated...

  13. Prolonged expression of the c-kit receptor in germ cells of intersex fetal testes

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, Ewa; Jørgensen, N; Müller, Jørn

    1996-01-01

    conditions which included 45,X/46,XY mosaicism; androgen insensitivity syndrome; and 46,XY/iso(p)Y mosaicism. Individuals with such disorders of sexual differentiation and Y-chromosome material carry a very high risk of developing testicular neoplasms. Fetal testicular germ cells of the intersex subjects...... expressed Kit at a later developmental age than controls, in which no Kit protein was detectable beyond the 15th week of gestation. This finding may indicate a disturbance of the chronology of germ cell development, or it may suggest a change of the regulation of c-kit expression in subjects with disorders...

  14. Testicular germ cell cancer incidence in an immigration perspective, Denmark, 1978 to 2003

    DEFF Research Database (Denmark)

    Schmiedel, Sven; Schüz, Joachim; Skakkebaek, Niels E

    2010-01-01

    The incidence rate of testicular germ cell cancer in Denmark increased up to the 1990s to become among the highest in the world. Since recently rate stabilization was suggested, we determined whether it is due to an increasing number of immigrants at lower risk for this cancer.......The incidence rate of testicular germ cell cancer in Denmark increased up to the 1990s to become among the highest in the world. Since recently rate stabilization was suggested, we determined whether it is due to an increasing number of immigrants at lower risk for this cancer....

  15. Research of Wheat Germ Foaming Capacity in Dairy Ice-Cream Composition

    Directory of Open Access Journals (Sweden)

    V.V. Martich

    2013-09-01

    Full Text Available Surface activity of grain component in model systems and in the milk ice cream is investigated. It is found that increase of wheat germ comtent in model systems and mixtures leads to a corresponding decrease in surface tension in the presence of surface-active plant protein. The expediency of previous frying and shredding of plant material to improve its foaming ability in the milk mixtures is proved. The need of wheat germ hydration before its use to improve functional and technological properties in the ice cream is confirmed.

  16. New insights into human primordial germ cells and early embryonic development from single-cell analysis.

    Science.gov (United States)

    Otte, Jörg; Wruck, Wasco; Adjaye, James

    2017-08-01

    Human preimplantation developmental studies are difficult to accomplish due to associated ethical and moral issues. Preimplantation cells are rare and exist only in transient cell states. From a single cell, it is very challenging to analyse the origination of the heterogeneity and complexity inherent to the human body. However, recent advances in single-cell technology and data analysis have provided new insights into the process of early human development and germ cell specification. In this Review, we examine the latest single-cell datasets of human preimplantation embryos and germ cell development, compare them to bulk cell analyses, and interpret their biological implications. © 2017 Federation of European Biochemical Societies.

  17. Congenital Cerebellar Mixed Germ Cell Tumor Presenting with Hemorrhage in a Newborn

    International Nuclear Information System (INIS)

    Kim, Sung Mok; Kim, Ji Hye; Yoo, So Young; Park, Won Soon; Jang, Yun Sil; Shin, Hyung Jin; Suh, Yeon Lim

    2008-01-01

    We report here on a neonate with congenital cerebellar mixed germ cell tumor, and this initially presented as cerebellar hemorrhage. Postnatal cranial ultrasonography revealed an echogenic cerebellar mass that exhibited the signal characteristics of hemorrhage rather than tumor on MR images. The short-term follow-up images also suggested a resolving cerebellar hemorrhage. One month later, the neonate developed vomiting. A second set of MR images demonstrated an enlarged mass that exhibited changed signal intensity at the same site, which suggested a neoplasm. Histological examination after the surgical resection revealed a mixed germ cell tumor

  18. Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

    Energy Technology Data Exchange (ETDEWEB)

    Kheradmand, Arash, E-mail: arashkheradmand@yahoo.com [Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Dezfoulian, Omid [Department of Pathobiology, School of Veterinary Medicine, Lorestan University, Khorram Abad (Iran, Islamic Republic of); Alirezaei, Masoud [Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Rasoulian, Bahram [Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khorram Abad (Iran, Islamic Republic of)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact

  19. Immunohistochemical expression of embryonal marker TRA-1-60 in carcinoma in situ and germ cell tumors of the testis

    DEFF Research Database (Denmark)

    Giwercman, Alexander; Andrews, P W; Jørgensen, N

    1993-01-01

    Testicular cancer is preceded by the noninvasive stage of carcinoma in situ (CIS). According to a recent hypothesis, testicular CIA cells are germ cells transformed in fetal life. The idea of an embryonal origin of testicular germ cell neoplasia would be strengthened by the finding of antigenic...

  20. Epidemiological study of paediatric germ cell tumours revealed the incidence and distribution that was expected, but a low mortality rate

    DEFF Research Database (Denmark)

    Evers, Madeline; Rechnitzer, Catherine; Graem, Niels

    2017-01-01

    Aim: Germ cell tumours (GCTs) are a rare heterogeneous tumour group derived from primordial germ cells, which can be benign or malignant and occur in the gonads or extragonadally. This study mapped the paediatric GCTs in Denmark from 1984 to 2013 to study the incidence and outcome. Methods: We id...

  1. Cell fate establishment during early development of cyprinid fishes, with special emphasis on the formation of the primordial germ cells

    NARCIS (Netherlands)

    Gevers, P.

    1992-01-01

    Cell fates can be established either by preformation or by epigenesis. With respect to primordial germ cells (PGCs) it has been shown that the Amphibia exhibit both types of cell fate establishment. Therefore, it is important to study the germ cell origin of the evolutionary lower class of

  2. Development of a new approach for targeted gene editing in primordial germ cells using TALENs in Xenopus

    Directory of Open Access Journals (Sweden)

    Keisuke Nakajima

    2015-02-01

    Full Text Available A gene of interest can be efficiently modified using transcription activator-like effector nucleases (TALENs (Christian et al., 2010;Li et al., 2011. However, if a target gene is essential for development, growth and fertility, use of TALENs with high mutagenic activity in F0 frogs could result in developmental disorders or sterility, which would reduce the number of F1 progeny and make F1 phenotypical analysis difficult. We used the 3′ untranslated region of DEADSouth gene (DS-3′ of Xenopus tropicalis to solve this problem, because the addition of the DS-3′ to mRNA is known to induce primordial germ cell (PGC-specific expression and reduce the stability in somatic cells of mRNA in Xenopus laevis. At first, we inserted the X. tropicalis DS-3′ downstream of the EGFP termination codon and confirmed that the EGFP expression was specifically detected in PGCs for three weeks. Therefore, we inserted the DS-3′ downstream of the termination codon of the TALEN coding sequence. The tyrosinase gene was selected as the target gene for TALEN because the bi-allelic mutation of this gene is easily discernible by the albino phenotype. When fertilized eggs were microinjected with TALEN mRNAs fused to the DS-3′, their sperm and oocytes had a high rate (84–100% of target-gene modification in contrast to the lower rate (0–45% of nucleotide alteration observed in somatic cells.

  3. Role of Non-Coding RNAs in the Transgenerational Epigenetic Transmission of the Effects of Reprotoxicants

    Directory of Open Access Journals (Sweden)

    Eduardo Larriba

    2016-03-01

    Full Text Available Non-coding RNAs (ncRNAs are regulatory elements of gene expression and chromatin structure. Both long and small ncRNAs can also act as inductors and targets of epigenetic programs. Epigenetic patterns can be transmitted from one cell to the daughter cell, but, importantly, also through generations. Diversity of ncRNAs is emerging with new and surprising roles. Functional interactions among ncRNAs and between specific ncRNAs and structural elements of the chromatin are drawing a complex landscape. In this scenario, epigenetic changes induced by environmental stressors, including reprotoxicants, can explain some transgenerationally-transmitted phenotypes in non-Mendelian ways. In this review, we analyze mechanisms of action of reprotoxicants upon different types of ncRNAs and epigenetic modifications causing transgenerationally transmitted characters through germ cells but affecting germ cells and reproductive systems. A functional model of epigenetic mechanisms of transgenerational transmission ncRNAs-mediated is also proposed.

  4. Comparison of Radiation Transport Codes, HZETRN, HETC and FLUKA, Using the 1956 Webber SPE Spectrum

    Science.gov (United States)

    Heinbockel, John H.; Slaba, Tony C.; Blattnig, Steve R.; Tripathi, Ram K.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Clowdsley, Martha S.; hide

    2009-01-01

    Protection of astronauts and instrumentation from galactic cosmic rays (GCR) and solar particle events (SPE) in the harsh environment of space is of prime importance in the design of personal shielding, spacec raft, and mission planning. Early entry of radiation constraints into the design process enables optimal shielding strategies, but demands efficient and accurate tools that can be used by design engineers in every phase of an evolving space project. The radiation transport code , HZETRN, is an efficient tool for analyzing the shielding effectiveness of materials exposed to space radiation. In this paper, HZETRN is compared to the Monte Carlo codes HETC-HEDS and FLUKA, for a shield/target configuration comprised of a 20 g/sq cm Aluminum slab in front of a 30 g/cm^2 slab of water exposed to the February 1956 SPE, as mode led by the Webber spectrum. Neutron and proton fluence spectra, as well as dose and dose equivalent values, are compared at various depths in the water target. This study shows that there are many regions where HZETRN agrees with both HETC-HEDS and FLUKA for this shield/target configuration and the SPE environment. However, there are also regions where there are appreciable differences between the three computer c odes.

  5. The Aesthetics of Coding

    DEFF Research Database (Denmark)

    Andersen, Christian Ulrik

    2007-01-01

    Computer art is often associated with computer-generated expressions (digitally manipulated audio/images in music, video, stage design, media facades, etc.). In recent computer art, however, the code-text itself – not the generated output – has become the artwork (Perl Poetry, ASCII Art, obfuscated...... code, etc.). The presentation relates this artistic fascination of code to a media critique expressed by Florian Cramer, claiming that the graphical interface represents a media separation (of text/code and image) causing alienation to the computer’s materiality. Cramer is thus the voice of a new ‘code...... avant-garde’. In line with Cramer, the artists Alex McLean and Adrian Ward (aka Slub) declare: “art-oriented programming needs to acknowledge the conditions of its own making – its poesis.” By analysing the Live Coding performances of Slub (where they program computer music live), the presentation...

  6. Diversity within American cassava germ plasm based on RAPD markers

    Directory of Open Access Journals (Sweden)

    Carlos Colombo

    2000-03-01

    Full Text Available This work focuses on the genetic diversity of American cassava through RAPD molecular markers. The 126 genotypes studied were distributed on four geographical levels ranging from local to continental. Samples included ethnocultivars from the Santa Isabel community in the Brazilian Amazon, local cultivars collected in the State of São Paulo, native accessions from very diverse Brazilian regions, and representative accessions from the Centro Internacional de Agricultura Tropical (CIAT core collection. Eighty-eight polymorphic bands were analyzed. Results revealed the weak genetic structure of the cassava analyzed. The pattern formed by the first two axes of the principal coordinates analysis (PCoA revealed an overlapping of the São Paulo State genotype, the Brazilian group and the core collection accessions. The Santa Isabel ethnocultures formed a separate group. The weak genetic structure of cassava can be explained by the common practice of exchanging botanical material among small producers as well as by recombinations among genotypes. When the genotypes were analyzed using climatic data, the sample sites were found to be structured according to temperature and precipitation. RAPD markers proved very useful in the genetic diversity study, resulting in important implications for cassava germ plasm collections and genetic breeding.Este trabalho enfoca a diversidade genética de mandiocas americanas através de marcadores moleculares do tipo RAPD. Os 126 genótipos estudados estão distribuídos em quatro escalas geográficas, indo do local ao continental, ou seja, etnocultivares de uma comunidade chamada Santa Isabel, na Amazônia brasileira, cultivares locais coletados no Estado de São Paulo, um grupo representado por acessos oriundos das mais diversas regiões brasileiras e acessos representantes da "core collection" do CIAT. Oitenta e oito bandas RAPD polimórficas foram retidas para as análises. A estrutura genética das mandiocas deste

  7. The aeroelastic code FLEXLAST

    Energy Technology Data Exchange (ETDEWEB)

    Visser, B. [Stork Product Eng., Amsterdam (Netherlands)

    1996-09-01

    To support the discussion on aeroelastic codes, a description of the code FLEXLAST was given and experiences within benchmarks and measurement programmes were summarized. The code FLEXLAST has been developed since 1982 at Stork Product Engineering (SPE). Since 1992 FLEXLAST has been used by Dutch industries for wind turbine and rotor design. Based on the comparison with measurements, it can be concluded that the main shortcomings of wind turbine modelling lie in the field of aerodynamics, wind field and wake modelling. (au)

  8. Gauge color codes

    DEFF Research Database (Denmark)

    Bombin Palomo, Hector

    2015-01-01

    Color codes are topological stabilizer codes with unusual transversality properties. Here I show that their group of transversal gates is optimal and only depends on the spatial dimension, not the local geometry. I also introduce a generalized, subsystem version of color codes. In 3D they allow t...... the transversal implementation of a universal set of gates by gauge fixing, while error-dectecting measurements involve only four or six qubits....

  9. Doubled Color Codes

    Science.gov (United States)

    Bravyi, Sergey

    Combining protection from noise and computational universality is one of the biggest challenges in the fault-tolerant quantum computing. Topological stabilizer codes such as the 2D surface code can tolerate a high level of noise but implementing logical gates, especially non-Clifford ones, requires a prohibitively large overhead due to the need of state distillation. In this talk I will describe a new family of 2D quantum error correcting codes that enable a transversal implementation of all logical gates required for the universal quantum computing. Transversal logical gates (TLG) are encoded operations that can be realized by applying some single-qubit rotation to each physical qubit. TLG are highly desirable since they introduce no overhead and do not spread errors. It has been known before that a quantum code can have only a finite number of TLGs which rules out computational universality. Our scheme circumvents this no-go result by combining TLGs of two different quantum codes using the gauge-fixing method pioneered by Paetznick and Reichardt. The first code, closely related to the 2D color code, enables a transversal implementation of all single-qubit Clifford gates such as the Hadamard gate and the π / 2 phase shift. The second code that we call a doubled color code provides a transversal T-gate, where T is the π / 4 phase shift. The Clifford+T gate set is known to be computationally universal. The two codes can be laid out on the honeycomb lattice with two qubits per site such that the code conversion requires parity measurements for six-qubit Pauli operators supported on faces of the lattice. I will also describe numerical simulations of logical Clifford+T circuits encoded by the distance-3 doubled color code. Based on a joint work with Andrew Cross.

  10. Phonological coding during reading

    Science.gov (United States)

    Leinenger, Mallorie

    2014-01-01

    The exact role that phonological coding (the recoding of written, orthographic information into a sound based code) plays during silent reading has been extensively studied for more than a century. Despite the large body of research surrounding the topic, varying theories as to the time course and function of this recoding still exist. The present review synthesizes this body of research, addressing the topics of time course and function in tandem. The varying theories surrounding the function of phonological coding (e.g., that phonological codes aid lexical access, that phonological codes aid comprehension and bolster short-term memory, or that phonological codes are largely epiphenomenal in skilled readers) are first outlined, and the time courses that each maps onto (e.g., that phonological codes come online early (pre-lexical) or that phonological codes come online late (post-lexical)) are discussed. Next the research relevant to each of these proposed functions is reviewed, discussing the varying methodologies that have been used to investigate phonological coding (e.g., response time methods, reading while eyetracking or recording EEG and MEG, concurrent articulation) and highlighting the advantages and limitations of each with respect to the study of phonological coding. In response to the view that phonological coding is largely epiphenomenal in skilled readers, research on the use of phonological codes in prelingually, profoundly deaf readers is reviewed. Finally, implications for current models of word identification (activation-verification model (Van Order, 1987), dual-route model (e.g., Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001), parallel distributed processing model (Seidenberg & McClelland, 1989)) are discussed. PMID:25150679

  11. MORSE Monte Carlo code

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, S.N.

    1984-01-01

    The MORSE code is a large general-use multigroup Monte Carlo code system. Although no claims can be made regarding its superiority in either theoretical details or Monte Carlo techniques, MORSE has been, since its inception at ORNL in the late 1960s, the most widely used Monte Carlo radiation transport code. The principal reason for this popularity is that MORSE is relatively easy to use, independent of any installation or distribution center, and it can be easily customized to fit almost any specific need. Features of the MORSE code are described.

  12. Bar Code Labels

    Science.gov (United States)

    1988-01-01

    American Bar Codes, Inc. developed special bar code labels for inventory control of space shuttle parts and other space system components. ABC labels are made in a company-developed anodizing aluminum process and consecutively marketed with bar code symbology and human readable numbers. They offer extreme abrasion resistance and indefinite resistance to ultraviolet radiation, capable of withstanding 700 degree temperatures without deterioration and up to 1400 degrees with special designs. They offer high resistance to salt spray, cleaning fluids and mild acids. ABC is now producing these bar code labels commercially or industrial customers who also need labels to resist harsh environments.

  13. QR codes for dummies

    CERN Document Server

    Waters, Joe

    2012-01-01

    Find out how to effectively create, use, and track QR codes QR (Quick Response) codes are popping up everywhere, and businesses are reaping the rewards. Get in on the action with the no-nonsense advice in this streamlined, portable guide. You'll find out how to get started, plan your strategy, and actually create the codes. Then you'll learn to link codes to mobile-friendly content, track your results, and develop ways to give your customers value that will keep them coming back. It's all presented in the straightforward style you've come to know and love, with a dash of humor thrown

  14. MORSE Monte Carlo code

    International Nuclear Information System (INIS)

    Cramer, S.N.

    1984-01-01

    The MORSE code is a large general-use multigroup Monte Carlo code system. Although no claims can be made regarding its superiority in either theoretical details or Monte Carlo techniques, MORSE has been, since its inception at ORNL in the late 1960s, the most widely used Monte Carlo radiation transport code. The principal reason for this popularity is that MORSE is relatively easy to use, independent of any installation or distribution center, and it can be easily customized to fit almost any specific need. Features of the MORSE code are described

  15. Tokamak Systems Code

    International Nuclear Information System (INIS)

    Reid, R.L.; Barrett, R.J.; Brown, T.G.

    1985-03-01

    The FEDC Tokamak Systems Code calculates tokamak performance, cost, and configuration as a function of plasma engineering parameters. This version of the code models experimental tokamaks. It does not currently consider tokamak configurations that generate electrical power or incorporate breeding blankets. The code has a modular (or subroutine) structure to allow independent modeling for each major tokamak component or system. A primary benefit of modularization is that a component module may be updated without disturbing the remainder of the systems code as long as the imput to or output from the module remains unchanged

  16. ARC Code TI: ACCEPT

    Data.gov (United States)

    National Aeronautics and Space Administration — ACCEPT consists of an overall software infrastructure framework and two main software components. The software infrastructure framework consists of code written to...

  17. On {\\sigma}-LCD codes

    OpenAIRE

    Carlet, Claude; Mesnager, Sihem; Tang, Chunming; Qi, Yanfeng

    2017-01-01

    Linear complementary pairs (LCP) of codes play an important role in armoring implementations against side-channel attacks and fault injection attacks. One of the most common ways to construct LCP of codes is to use Euclidean linear complementary dual (LCD) codes. In this paper, we first introduce the concept of linear codes with $\\sigma$ complementary dual ($\\sigma$-LCD), which includes known Euclidean LCD codes, Hermitian LCD codes, and Galois LCD codes. As Euclidean LCD codes, $\\sigma$-LCD ...

  18. Proteínas do feijão preto sem casca: digestibilidade em animais convencionais e isentos de germes (germ-free Proteins of dehulled black beans: digestibility in conventional and germ-free animals

    Directory of Open Access Journals (Sweden)

    Conceição Angelina dos Santos PEREIRA

    2002-01-01

    Full Text Available O feijão (Phaseolus vulgaris, L. é uma leguminosa de grande importância para a dieta da população brasileira. No entanto, um de seus maiores problemas é representado pelo baixo valor nutricional de suas proteínas, decorrente, por um lado, da sua baixa digestibilidade e, de outro, do teor e biodisponibilidade reduzidos de aminoácidos sulfurados. Com o objetivo de avaliar a digestibilidade das proteínas albumina e globulina do feijão preto sem casca, foram realizados ensaios biológicos com camundongos isentos de germes e convencionais e com ratos (Wistar, recém-desmamados, com idade de 21 a 25 dias. Avaliou-se ainda o Escore Químico Corrigido pela Digestibilidade da Proteína. A digestibilidade verdadeira no experimento com camundongos isentos de germes foi de 90,21 e 90,00%, no teste com camundongos convencionais foi de 85,53 e 86,73%, e no experimento com ratos foi de 82,62 e 68,53%, para albumina e globulina, respectivamente. O Escore Químico Corrigido pela Digestibilidade da Proteína foi de 61,00% para a albumina e 51,00% para a globulina. A digestibilidade determinada em animais isentos de germes foi superior aos valores encontrados em animais convencionais, sugerindo que a flora intestinal esteja contribuindo para elevar o teor de nitrogênio nas fezes dos animais convencionais, e, portanto, esteja sendo subestimada a digestibilidade verdadeira do feijão.The bean (Phaseolus vulgaris, L. is a legume of great importance in the Brazilian typical diet. Nevertheless, it presents a low protein quality due to its poor digestibility and low levels and bioavailability of its sulfur aminoacids. The aim of this study was to evaluate the digestibility of albumin and globulin protein fractions of dehulled black beans in conventional and germ-free mice and also in weaning rats (Wistar of 21 to 25 days of age. Protein Digestibility Corrected Amino Acid Score was also determined. True digestibility values in germ-free mice were 90.21 and 90

  19. Soy Germed Protein Plus Zn as an Inducer Insulin Secretion on Type-2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    HERY WINARSI

    2010-09-01

    Full Text Available Hyperglicemic induces pancreatic cells to produce inadequate insulin. However, previous studies revealed that soy protein induce pancreatic cells to secrete insulin. Hence, this study was aimed to investigate effect of soy germed protein on the insulin and blood glucose level of type-2 diabetes mellitus with Zn enrichment. The research involved twenty four women that characterized with having more blood glucose level than normal, body mass index more than twenty three kg/m2, and age more than fourty years old. They were divided into three groups randomly, eight woman for each group. The first, second and third group were treated respectively with milk containing soy germed protein plus Zn, this product without Zn, and placebo, all for two months. Blood samples were taken at baseline, one and two months after observation. Results showed that two months after observation the insulin level increased from 194.79 to 519.82 pmol/ml (P = 0.033 in group consuming milk containing soy germed protein with or without Zn, supported by significantly reduced blood glucose level. This result might be correlated with the potency of isoflavones in soy germ protein to protect pancreatic beta cellsmembrane from free radicals attack. Therefore, this maintain the cells integrity and to secrete optimal insulin.

  20. Immunohistochemical Examination for the Distribution of Podoplanin-Expressing Cells in Developing Mouse Molar Tooth Germs

    Science.gov (United States)

    Imaizumi, Yuri; Amano, Ikuko; Tsuruga, Eichi; Kojima, Hiroshi; Sawa, Yoshihiko

    2010-01-01

    We recently reported the expression of podoplanin in the apical bud of adult mouse incisal tooth. This study was aimed to investigate the distribution of podoplanin-expressing cells in mouse tooth germs at several developing stages. At the bud stage podoplanin was expressed in oral mucous epithelia and in a tooth bud. At the cap stage podoplanin was expressed on inner and outer enamel epithelia but not in mesenchymal cells expressing the neural crest stem cell marker nestin. At the early bell stage nestin and podoplanin were expressed in cervical loop and odontoblasts. At the root formation stage both nestin and podoplanin were weakly expressed in odontoblasts generating radicular dentin. Podoplanin expression was also found in the Hertwig epithelial sheath. These results suggest that epithelial cells of developing tooth germ acquire the ability to express nestin, and that tooth germ epithelial cells maintain the ability to express podoplanin in oral mucous epithelia. The expression of podoplanin in odontoblasts was induced as tooth germ development advanced, but was suppressed with the completion of the primary dentin, suggesting that podoplanin may be involved in the cell growth of odontoblasts. Nestin may function as an intermediate filament that binds podoplanin in odontoblasts. PMID:21060740

  1. The emerging phenotype of the testicular carcinoma in situ germ cell

    DEFF Research Database (Denmark)

    Rajpert-De Meyts, Ewa; Bartkova, Jirina; Samson, Michel

    2003-01-01

    of differentiation and pluripotency, CIS cells found in adult patients seem to be predestined for further malignant progression into one or the other of the two main types of overt tumours. A new concept of phenotypic continuity of differentiation of germ cells along germinal lineage with a gradual loss of embryonic...

  2. Treatment of metastatic germ cell tumor in a newly diagnised HIV ...

    African Journals Online (AJOL)

    This is a Testicular cancer suspect with lung metastases initially thought to ... An orchidectomy of the right testis was performed and histology revealed yolk sac tumor which is a type of a germ cell tumor (GCT). After the surgery, four cycles of BEP. (Bleomycin 30 ... ≥3 cm can be observed, reserving intervention for recurrent.

  3. Protective role of wheat germ oil on some biochemical parameters in irradiated rats

    International Nuclear Information System (INIS)

    Atia, A.I.; Darwish, M.M.; Sallam, M.H.

    2006-01-01

    Wheat germ oil is an organic nutritionally rich vegetable oil. It is an excellent source of vitamin E and essential fatty acids (octacosanol, linoleic and linolenic). The study confirmed the beneficial role of the used anti-oxidation agents as recommended radio-protectors due to their ability of scavenging free radicals produced by ionizing radiation. The efficacy of daily oral treatment of rats with wheat germ oil (10 mg/ Kg body wt) for 15 days to control many of the damaging effects of ionizing radiation when male rats were subjected to fractionated 8 Gy (2 Gy day after day) of gamma irradiation were studied. Blood samples were collected from animals at 10 and 15 days after treatment and/or exposure. In blood, the data obtained revealed that, radiation exposure caused significant increases in levels of malondialdehyde (MDA), triacylglycerol (TG), total cholesterol (TC), low-density lipoproteins (LDL) and glucose at the 10th day. Meanwhile, significant reduction in contents of total protein, albumin, globulins, high-density lipoproteins (HDL), vitamin E and glucose were recorded at the 15th day. Also, the majority of these parameters were estimated in liver tissues. The results revealed that administration of the natural product wheat germ oil partially ameliorated the radiation-induced biochemical disturbances. These effects were explained in the light of the presumed different mechanisms of wheat germ oil actions

  4. Absence of significant germ line p53 mutations in ovarian cancer patients.

    Science.gov (United States)

    Buller, R E; Skilling, J S; Kaliszewski, S; Niemann, T; Anderson, B

    1995-09-01

    Germ line mutations of the p53 gene have been described in the Li-Fraumeni Cancer Family Syndrome and occur in patients with multifocal gliomas, particularly those with a history of a metachronous cancer or a family history of cancer. p53 dysfunction is often associated with ovarian cancer. Patients with ovarian carcinoma frequently develop synchronous or metachronous cancers and may have a family history of this or related cancers. Thus, we hypothesized that germ line p53 mutations might be associated with a significant proportion of ovarian cancers. Germ line DNA isolated from peripheral leukocytes of 73 patients with ovarian carcinoma was screened for p53 sequence abnormalities utilizing single-strand conformation polymorphism analysis and direct PCR sequencing techniques. As many as 40% of this cohort of ovarian cancer patients from 67 families may represent familial phenotypes. Synchronous and metachronous cancers occurred in 19% of the cohort. Only two intron-based polymorphisms were found. Neither has been previously reported. One of these, in intron 6, occurred in three unrelated patients all of whom had a history of metachronous breast cancer. A polymorphism in intron 10 occurred in a patient with synchronous endometrial cancer. No classic germ line mutations of p53 were found.

  5. Superior Vena Cava Syndrome: A Presenting Feature of Mediastinal Germ Cell Tumor

    Directory of Open Access Journals (Sweden)

    Mahua Roy

    2010-04-01

    Full Text Available Superior vena cava syndrome (SVCS is rare in children. Non-Hodgkin’s Lymphoma (NHL is the most common cause of SVCS in children. This report an adolescent male who presented with SVCS due to mixed germ cell tumor (GCT of the anterior mediastinum with predominant yolk cell component. Such etiology of SVCS is rarely reported.

  6. Incorporating age into International Germ Cell Consensus Classification (IGCCC): a time to move forward?

    Science.gov (United States)

    Abdel-Rahman, Omar

    2018-01-01

    Older age is a poor prognostic indicator among patients with germ cell tumors. The current study evaluates an age-integrated international germ cell consensus classification (IGCCC) for advanced germ cell tumors. SEER database (2004-2014) was accessed through SEER*Stat program and both IGCCC and age-integrated IGCCC were calculated based on site of the primary, site of the metastasis and level of tumor markers. Overall survival analyses according to IGCCC and age-integrated IGCCC were conducted through Kaplan-Meier analysis. Overall survival was compared according to IGCCC and age-integrated IGCCC for patients with seminoma and Non-seminomatous germ cell tumors (NSGCTs). P values were significant (P <0.001) for all scenarios. c-index for seminoma for IGCCC was 0.553; c-index for seminoma for age-integrated IGCCC was 0.664;c-index for NSGCTs for IGCCC was 0.729; and c-index for NSGCTs for age-integrated IGCCC was 0.738. A Cox-regression multivariate model of factors affecting cancer-specific survival (adjusted for race and surgical treatment) was conducted. All P values for pair wise comparisons (among different age-integrated IGCCC categories) were significant for both seminoma and NSGCTs (P<0.01). Compared to traditional IGCCC, age-integrated IGCCC is more discriminatory and the new risk groups introduced within it are prognostically relevant.

  7. The Bile Acid Nuclear Receptor FXRα Is a Critical Regulator of Mouse Germ Cell Fate

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    Emmanuelle Martinot

    2017-07-01

    Full Text Available Spermatogenesis is the process by which spermatozoa are generated from spermatogonia. This cell population is heterogeneous, with self-renewing spermatogonial stem cells (SSCs and progenitor spermatogonia that will continue on a path of differentiation. Only SSCs have the ability to regenerate and sustain spermatogenesis. This makes the testis a good model to investigate stem cell biology. The Farnesoid X Receptor alpha (FXRα was recently shown to be expressed in the testis. However, its global impact on germ cell homeostasis has not yet been studied. Here, using a phenotyping approach in Fxrα−/− mice, we describe unexpected roles of FXRα on germ cell physiology independent of its effects on somatic cells. FXRα helps establish and maintain an undifferentiated germ cell pool and in turn influences male fertility. FXRα regulates the expression of several pluripotency factors. Among these, in vitro approaches show that FXRα controls the expression of the pluripotency marker Lin28 in the germ cells.

  8. TRA-1-60 - A NEW SERUM MARKER IN PATIENTS WITH GERM-CELL TUMORS

    NARCIS (Netherlands)

    MARRINK, J; ANDREWS, PW; VANBRUMMEN, PJ; DEJONG, HJ; SLEIJFER, DT; KOOPS, HS; OOSTERHUIS, JW

    1991-01-01

    TRA-1-60 is a monoclonal antibody (MAb) that recognizes a mucin-like antigenic determinant expressed on the surface of embryonal carcinoma (EC) progenitor cells. In order to determine whether this antigen is released into the serum of patients with a non-seminomatous germ-cell tumor (NSGCT), we

  9. Ectopic Expression of Testis Germ Cell Proteins in Cancer and Its Potential Role in Genomic Instability

    Directory of Open Access Journals (Sweden)

    Aaraby Yoheswaran Nielsen

    2016-06-01

    Full Text Available Genomic instability is a hallmark of human cancer and an enabling factor for the genetic alterations that drive cancer development. The processes involved in genomic instability resemble those of meiosis, where genetic material is interchanged between homologous chromosomes. In most types of human cancer, epigenetic changes, including hypomethylation of gene promoters, lead to the ectopic expression of a large number of proteins normally restricted to the germ cells of the testis. Due to the similarities between meiosis and genomic instability, it has been proposed that activation of meiotic programs may drive genomic instability in cancer cells. Some germ cell proteins with ectopic expression in cancer cells indeed seem to promote genomic instability, while others reduce polyploidy and maintain mitotic fidelity. Furthermore, oncogenic germ cell proteins may indirectly contribute to genomic instability through induction of replication stress, similar to classic oncogenes. Thus, current evidence suggests that testis germ cell proteins are implicated in cancer development by regulating genomic instability during tumorigenesis, and these proteins therefore represent promising targets for novel therapeutic strategies.

  10. Patterns of Glycoconjugate Distribution during Molar Tooth Germ Development in Mice

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    AR. Varasteh

    2007-09-01

    Full Text Available Objective: The aim of the present study was to evaluate the structure and distribution of Glycoconjugates during molar tooth germ development in mice.Materials and Methods: Sixteen tooth germs were obtained from BALB/c mice embryos 15 to 18 days post-gestation and fixed in 10% formalin. After routine tissue processing, 5μm sections were cut and stained with BSA1-B4 and PNA using the lectin histochemical method. All slides were evaluated by light microscopy.Results: Both lectins showed positive reaction in the tooth germ but with spatiotemporal differences. During bell stage, the reaction was strong with BSA1-B4 but moderate with PNA. Strong PNA uptake was observed in the odontoblastic and ameloblastic nuclei alongwith the apical cytoplasm of the ameloblasts.Conclusion: Although the lectins that were used in the present study recognize the same terminal sugar residue, they reacted with different disaccharide sequences with various penaltomer sugars. Therefore it may be assumed that the pattern of affinity for different parts of the developing tooth germ such as ameloblasts and odontoblasts is different in various lectins.

  11. Exposure to endocrine disruptor induces transgenerational epigenetic deregulation of microRNAs in primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Miguel A Brieño-Enríquez

    Full Text Available In mammals, germ cell differentiation is initiated in the Primordial Germ Cells (PGCs during fetal development. Prenatal exposure to environmental toxicants such as endocrine disruptors may alter PGC differentiation, development of the male germline and induce transgenerational epigenetic disorders. The anti-androgenic compound vinclozolin represents a paradigmatic example of molecule causing transgenerational effects on germ cells. We performed prenatal exposure to vinclozolin in mice and analyzed the phenotypic and molecular changes in three successive generations. A reduction in the number of embryonic PGCs and increased rate of apoptotic cells along with decrease of fertility rate in adult males were observed in F1 to F3 generations. Blimp1 is a crucial regulator of PGC differentiation. We show that prenatal exposure to vinclozolin deregulates specific microRNAs in PGCs, such as miR-23b and miR-21, inducing disequilibrium in the Lin28/let-7/Blimp1 pathway in three successive generations of males. As determined by global maps of cytosine methylation, we found no evidence for prominent changes in DNA methylation in PGCs or mature sperm. Our data suggest that embryonic exposure to environmental endocrine disruptors induces transgenerational epigenetic deregulation of expression of microRNAs affecting key regulatory pathways of germ cells differentiation.

  12. Quantitative histology of germ cells in the undescended testes of human fetuses, neonates and infants

    DEFF Research Database (Denmark)

    Cortes, D; Thorup, J M; Beck, B L

    1995-01-01

    PURPOSE: We investigated the number of germ cells per tubular cross section and testicular weight in cryptorchid fetuses, neonates and infants, and characterized additional abnormalities. MATERIALS AND METHODS: Our series comprised 35 fetuses and 58 boys with cryptorchidism, and 22 normal fetuses...

  13. A novel role forsox7inXenopusearly primordial germ cell development: mining the PGC transcriptome.

    Science.gov (United States)

    Butler, Amanda M; Owens, Dawn A; Wang, Lingyu; King, Mary Lou

    2018-01-08

    Xenopus primordial germ cells (PGCs) are determined by the presence of maternally derived germ plasm. Germ plasm components both protect PGCs from somatic differentiation and begin a unique gene expression program. Segregation of the germline from the endodermal lineage occurs during gastrulation, and PGCs subsequently initiate zygotic transcription. However, the gene network(s) that operate to both preserve and promote germline differentiation are poorly understood. Here, we utilized RNA-sequencing analysis to comprehensively interrogate PGC and neighboring endoderm cell mRNAs after lineage segregation. We identified 1865 transcripts enriched in PGCs compared with endoderm cells. We next compared the PGC-enriched transcripts with previously identified maternal, vegetally enriched transcripts and found that ∼38% of maternal transcripts were enriched in PGCs, including sox7 PGC-directed sox7 knockdown and overexpression studies revealed an early requirement for sox7 in germ plasm localization, zygotic transcription and PGC number. We identified pou5f3.3 as the most highly expressed and enriched POU5F1 homolog in PGCs. We compared the Xenopus PGC transcriptome with human PGC transcripts and showed that 80% of genes are conserved, underscoring the potential usefulness of Xenopus for understanding human germline specification. © 2018. Published by The Company of Biologists Ltd.

  14. FGF, Insulin, and SMAD Signaling Cooperate for Avian Primordial Germ Cell Self-Renewal

    Science.gov (United States)

    Whyte, Jemima; Glover, James D.; Woodcock, Mark; Brzeszczynska, Joanna; Taylor, Lorna; Sherman, Adrian; Kaiser, Pete; McGrew, Michael J.

    2015-01-01

    Summary Precise self-renewal of the germ cell lineage is fundamental to fertility and reproductive success. The early precursors for the germ lineage, primordial germ cells (PGCs), survive and proliferate in several embryonic locations during their migration to the embryonic gonad. By elucidating the active signaling pathways in migratory PGCs in vivo, we were able to create culture conditions that recapitulate this embryonic germ cell environment. In defined medium conditions without feeder cells, the growth factors FGF2, insulin, and Activin A, signaling through their cognate-signaling pathways, were sufficient for self-renewal of germline-competent PGCs. Forced expression of constitutively active MEK1, AKT, and SMAD3 proteins could replace their respective upstream growth factors. Unexpectedly, we found that BMP4 could replace Activin A in non-clonal growth conditions. These defined medium conditions identify the key molecular pathways required for PGC self-renewal and will facilitate efforts in biobanking of chicken genetic resources and genome editing. PMID:26677769

  15. Neurl4 contributes to germ cell formation and integrity in Drosophila

    Directory of Open Access Journals (Sweden)

    Jennifer Jones

    2015-08-01

    Full Text Available Primordial germ cells (PGCs form at the posterior pole of the Drosophila embryo, and then migrate to their final destination in the gonad where they will produce eggs or sperm. Studies of the different stages in this process, including assembly of germ plasm in the oocyte during oogenesis, specification of a subset of syncytial embryonic nuclei as PGCs, and migration, have been informed by genetic analyses. Mutants have defined steps in the process, and the identities of the affected genes have suggested biochemical mechanisms. Here we describe a novel PGC phenotype. When Neurl4 activity is reduced, newly formed PGCs frequently adopt irregular shapes and appear to bud off vesicles. PGC number is also reduced, an effect exacerbated by a separate role for Neurl4 in germ plasm formation during oogenesis. Like its mammalian homolog, Drosophila Neurl4 protein is concentrated in centrosomes and downregulates centrosomal protein CP110. Reducing CP110 activity suppresses the abnormal PGC morphology of Neurl4 mutants. These results extend prior analyses of Neurl4 in cultured cells, revealing a heightened requirement for Neurl4 in germ-line cells in Drosophila.

  16. FGF, Insulin, and SMAD Signaling Cooperate for Avian Primordial Germ Cell Self-Renewal

    Directory of Open Access Journals (Sweden)

    Jemima Whyte

    2015-12-01

    Full Text Available Precise self-renewal of the germ cell lineage is fundamental to fertility and reproductive success. The early precursors for the germ lineage, primordial germ cells (PGCs, survive and proliferate in several embryonic locations during their migration to the embryonic gonad. By elucidating the active signaling pathways in migratory PGCs in vivo, we were able to create culture conditions that recapitulate this embryonic germ cell environment. In defined medium conditions without feeder cells, the growth factors FGF2, insulin, and Activin A, signaling through their cognate-signaling pathways, were sufficient for self-renewal of germline-competent PGCs. Forced expression of constitutively active MEK1, AKT, and SMAD3 proteins could replace their respective upstream growth factors. Unexpectedly, we found that BMP4 could replace Activin A in non-clonal growth conditions. These defined medium conditions identify the key molecular pathways required for PGC self-renewal and will facilitate efforts in biobanking of chicken genetic resources and genome editing.

  17. Human primordial germ cell commitment in vitro associates with a unique PRDM14 expression profile.

    Science.gov (United States)

    Sugawa, Fumihiro; Araúzo-Bravo, Marcos J; Yoon, Juyong; Kim, Kee-Pyo; Aramaki, Shinya; Wu, Guangming; Stehling, Martin; Psathaki, Olympia E; Hübner, Karin; Schöler, Hans R

    2015-04-15

    Primordial germ cells (PGCs) develop only into sperm and oocytes in vivo. The molecular mechanisms underlying human PGC specification are poorly understood due to inaccessibility of cell materials and lack of in vitro models for tracking the earliest stages of germ cell development. Here, we describe a defined and stepwise differentiation system for inducing pre-migratory PGC-like cells (PGCLCs) from human pluripotent stem cells (PSCs). In response to cytokines, PSCs differentiate first into a heterogeneous mesoderm-like cell population and then into PGCLCs, which exhibit minimal PRDM14 expression. PGC specification in humans is similar to the murine process, with the sequential activation of mesodermal and PGC genes, and the suppression of neural induction and of de novo DNA methylation, suggesting that human PGC formation is induced via epigenesis, the process of germ cell specification via inductive signals from surrounding somatic cells. This study demonstrates that PGC commitment in humans shares key features with that of the mouse, but also highlights key differences, including transcriptional regulation during the early stage of human PGC development (3-6 weeks). A more comprehensive understanding of human germ cell development may lead to methodology for successfully generating PSC-derived gametes for reproductive medicine. © 2015 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  18. Trans-generational epigenetic regulation of C. elegans primordial germ cells

    Directory of Open Access Journals (Sweden)

    Furuhashi Hirofumi

    2010-08-01

    Full Text Available Abstract Background The processes through which the germline maintains its continuity across generations has long been the focus of biological research. Recent studies have suggested that germline continuity can involve epigenetic regulation, including regulation of histone modifications. However, it is not clear how histone modifications generated in one generation can influence the transcription program and development of germ cells of the next. Results We show that the histone H3K36 methyltransferase maternal effect sterile (MES-4 is an epigenetic modifier that prevents aberrant transcription activity in Caenorhabditis elegans primordial germ cells (PGCs. In mes-4 mutant PGCs, RNA Pol II activation is abnormally regulated and the PGCs degenerate. Genetic and genomewide analyses of MES-4-mediated H3K36 methylation suggest that MES-4 activity can operate independently of ongoing transcription, and may be predominantly responsible for maintenance methylation of H3K36 in germline-expressed loci. Conclusions Our data suggest a model in which MES-4 helps to maintain an 'epigenetic memory' of transcription that occurred in germ cells of previous generations, and that MES-4 and its epigenetic product are essential for normal germ cell development.

  19. Critical function of AP-2gamma/TCFAP2C in mouse embryonic germ cell maintenance

    NARCIS (Netherlands)

    S. Weber (Susanne); D. Eckert (Dawid); D. Nettersheim (Daniel); A.J.M. Gillis (Ad); S. Schäfer (Sabine); P. Kuckenberg (Peter); J. Ehlermann (Julia); U. Werling (Uwe); K. Biermann (Katharina); L.H.J. Looijenga (Leendert); H. Schorle (Hubert)

    2010-01-01

    textabstractFormation of the germ cell lineage involves multiple processes, including repression of somatic differentiation and reacquisition of pluripotency as well as a unique epigenetic constitution. The transcriptional regulator Prdm1 has been identified as a main coordinator of this process,

  20. bFGF signaling-mediated reprogramming of porcine primordial germ cells.

    Science.gov (United States)

    Zhang, Yu; Ma, Jing; Li, Hai; Lv, Jiawei; Wei, Renyue; Cong, Yimei; Liu, Zhonghua

    2016-05-01

    Primordial germ cells (PGCs) have the ability to be reprogrammed into embryonic germ cells (EGCs) in vitro and are an alternative source of embryonic stem cells. Other than for the mouse, the systematic characterization of mammalian PGCs is still lacking, especially the process by which PGCs convert to pluripotency. This hampers the understanding of germ cell development and the derivation of authenticated EGCs from other species. We observed the morphological development of the genital ridge from Bama miniature pigs and found primary sexual differentiation in the E28 porcine embryo, coinciding with Blimp1 nuclear exclusion in PGCs. To explore molecular events involved in porcine PGC reprogramming, transcriptome data of porcine EGCs and fetal fibroblasts (FFs) were assembled and 1169 differentially expressed genes were used for Gene Ontology analysis. These genes were significantly enriched in cell-surface receptor-linked signal transduction, in agreement with the activation of LIF/Stat3 signaling and FGF signaling during the derivation of porcine EG-like cells. Using a growth-factor-defined culture system, we explored the effects of bFGF on the process and found that bFGF not only functioned at the very beginning of PGC dedifferentiation by impeding Blimp1 nuclear expression via a PI3K/AKT-dependent pathway but also maintained the viability of cultured PGCs thereafter. These results provide further insights into the development of germ cells from livestock and the mechanism of porcine PGC reprogramming.

  1. DAZL Limits Pluripotency, Differentiation, and Apoptosis in Developing Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Hsu-Hsin Chen

    2014-11-01

    Full Text Available The scarcity of primordial germ cells (PGCs in the developing mammalian embryo hampers robust biochemical analysis of the processes that underlie early germ cell formation. Here, we demonstrate that DAZL, a germ cell-specific RNA binding protein, is a robust PGC marker during in vitro germ cell development. Using Dazl-GFP reporter ESCs, we demonstrate that DAZL plays a central role in a large mRNA/protein interactive network that blocks the translation of core pluripotency factors, including Sox2 and Sall4, as well as of Suz12, a polycomb family member required for differentiation of pluripotent cells. Thus, DAZL limits both pluripotency and somatic differentiation in nascent PGCs. In addition, we observed that DAZL associates with mRNAs of key Caspases and similarly inhibits their translation. This elegant fail-safe mechanism ensures that, whereas loss of DAZL results in prolonged expression of pluripotency factors, teratoma formation is avoided due to the concomitant activation of the apoptotic cascade.

  2. Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae).

    Science.gov (United States)

    Gribbins, Kevin; Anzalone, Marla; Collier, Matthew; Granados-González, Gisela; Villagrán-Santa Cruz, Maricela; Hernández-Gallegos, Oswaldo

    2011-10-01

    Sceloporus bicanthalis is a viviparous lizard that lives at higher elevations in Mexico. Adult male S. bicanthalis were collected (n = 36) from the Nevado de Toluca, Mexico (elevation is 4200 m) during August to December, 2007 and January to July, 2008. Testes were extracted, fixed in Trumps, and dehydrated in a graded series of ethanol. Tissues were embedded, sectioned (2 μm), stained, and examined via a light microscope to determine the spermatogenic developmental strategy of S. bicanthalis. In all months examined, the testes were spermiogenically active; based on this, plus the presence of sperm in the lumina of seminiferous tubules, we inferred that S. bicanthalis had year-round or continuous spermatogenesis, unlike most reptiles that occupy a temperate or montane habitat. It was recently reported that seasonally breeding reptiles had a temporal germ cell development strategy similar to amphibians, where germ cells progress through spermatogenesis as a single population, which leads to a single spermiation event. This was much different than spatial development within the testis of other derived amniotes. We hypothesized that germ cell development was temporal in S. bicanthalis. Therefore, we wanted to determine whether reptiles that practice continuous spermatogenesis have a mammalian-like spatial germ cell development, which is different than the typical temperate reptile exhibiting a temporal development. In the present study, S. bicanthalis had a temporal development strategy, despite its continuous spermatogenic cycle, making them similar to tropical anoles. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Survey and Detection of Endophytic Fungi in Lolium Germ Plasm by Direct Staining and Aphid Assays

    Science.gov (United States)

    A. Dan Wilson; Stephen L. Clement; Walter J. Kaiser

    1991-01-01

    Clavicipitaceous anamorphic endophytes were detected in 28 of 85 accessions from five of eight species in a collection of Lolium germ plasm. Comparative descriptions of endophytic mycelium in seeds of L. multiflorum, L. perenne, L. persicum, L. rigidum, and L. temulentum revealed morphological characteristics...

  4. Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

    Energy Technology Data Exchange (ETDEWEB)

    Selle, F.; Gligorov, J. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Pierre & Marie Curie University (UPMC Paris VI), Paris (France); Richard, S.; Khalil, A. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Alexandre, I. [Medical Oncology Department, Hospital Centre of Bligny, Briis-sous-Forges (France); Avenin, D.; Provent, S.; Soares, D.G. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Lotz, J.P. [Medical Oncology and Cellular Therapy Department, Hospital Tenon, Public Assistance Hospitals of Paris, Alliance for Cancer Research (APREC), Paris (France); Pierre & Marie Curie University (UPMC Paris VI), Paris (France)

    2014-11-04

    Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis.

  5. Carcinoma in situ testis, the progenitor of testicular germ cell tumours

    DEFF Research Database (Denmark)

    Hoei-Hansen, C E; Rajpert-De Meyts, E; Daugaard, G

    2005-01-01

    Testicular germ cell tumours (TGCT), including seminomas, embryonal carcinomas, teratomas and yolk sac tumours, have a common precursor, the carcinoma in situ (CIS) cell. Recent gene expression studies displaying close similarity of CIS cells to embryonic stem cells support the longstanding theory...

  6. Comparative genomic and in situ hybridization of germ cell tumors of the infantile testis

    NARCIS (Netherlands)

    Mostert, M; Rosenberg, C; Stoop, H; Schuyer, M; Timmer, A; Oosterhuis, W; Looijenga, L

    Chromosomal information on germ cell tumors of the infantile testis, ie, teratomas and yolk sac tumors, is limited and controversial. We studied two teratomas and four yolk sac tumors using comparative genomic hybridization (CGH) and in situ hybridization. No chromosomal anomalies were found in the

  7. The current algebra on the circle as a germ of local field theories

    International Nuclear Information System (INIS)

    Buchholz, D.; Mack, G.; Todorov, I.; Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika)

    1988-01-01

    Methods of algebraic quantum field theory are used to classify all field- and observable algebras, whose common germ is the U(1)-current algebra. An elementary way is described to compute characters of such algebras. It exploits the Kubo-Martin-Schwinger condition for Gibbs states. (orig.)

  8. Germ Cells Get by with a Little Cannibalistic Help from Their Friends.

    Science.gov (United States)

    Krishna, Shefali; Overholtzer, Michael

    2016-12-19

    During development, primordial germ cells (PGCs) navigate a complex journey to generate the germline. In a recent paper in Nature Cell Biology, Nance and colleagues (Abdu et al., 2016) have discovered an unexpected step along the way: PGCs get cut in half by endodermal cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Molecular cytogenetics of human germ cell tumours : i(12p) and related chromosomal anomalies

    NARCIS (Netherlands)

    Geurts van Kessel, A; Suijkerbuijk, R F; Sinke, R J; Looijenga, L; Oosterhuis, J W; de Jong, B

    1993-01-01

    Human testicular germ cell tumours (TGCTs) comprise a heterogeneous group of solid neoplasms. These tumours are characterized by a highly specific chromosomal anomaly, i.e. an isochromosome of the short arm of chromosome 12. At present, this i(12p) chromosome has been observed in about 80% of TGCTs.

  10. Lipoprotein lipase and endothelial lipase in human testis and in germ cell neoplasms

    DEFF Research Database (Denmark)

    Nielsen, J E; Lindegaard, M L; Friis-Hansen, L

    2009-01-01

    The aim of this study was to investigate endothelial lipase (EL, LIPG) and lipoprotein lipase (LPL) mRNA and protein expression in normal human testis and testicular germ cell tumours (GCT). Both EL and LPL were expressed in normal seminiferous tubules and in the interstitial compartment. EL mRNA...

  11. Depletion of endogenous germ cells in tree shrews in preparation for spermatogonial transplantation.

    Science.gov (United States)

    Liu, Tingting; Guo, Ying; Yan, Lanzhen; Sun, Bin; Zheng, Ping; Zhao, Xudong

    2017-09-01

    To achieve successful spermatogonial transplantation, endogenous germ cells must be depleted in recipient animals to allow donor germ cells to colonize efficiently. Busulfan is commonly used for the depletion of endogenous germ cells in recipient males. However, the optimal dose of busulfan is species-specific, and the optimal dose in tree shrews is yet to be determined. The current study aimed to determine the optimal dose of busulfan for effective suppression of endogenous spermatogenesis in tree shrews. Different doses (15, 20, 25, 30, 35, 40 and 45 mg/kg) of busulfan were injected into tree shrews intraperitoneally. Survival rates of the different treatment groups were calculated at 2 weeks and body weights were measured at 4, 6, 8, 10 and 28 weeks post-busulfan treatment. The testes were also removed and weighed at 4, 6, 8, 10 and 28 weeks post-treatment, and the cross and longitude diameters of the testes and diameters of the seminiferous tubules were measured and histologically evaluated. It was observed that there were no significant differences in the survival rates between the 15-35 mg/kg treatment groups and the control group (P>0.05), while the survival rate of the 40 mg/kg treatment group significantly decreased relative to the control group (Pendogenous germ cells in tree shrews. This dose led to maximum suppression of endogenous spermatogenesis while maintaining an acceptable survival rate of >50% of the lethal dose of busulfan for tree shrews.

  12. Intensive chemotherapy as salvage treatment for solid tumors: focus on germ cell cancer

    International Nuclear Information System (INIS)

    Selle, F.; Gligorov, J.; Richard, S.; Khalil, A.; Alexandre, I.; Avenin, D.; Provent, S.; Soares, D.G.; Lotz, J.P.

    2014-01-01

    Germ cell tumors present contrasting biological and molecular features compared to many solid tumors, which may partially explain their unusual sensitivity to chemotherapy. Reduced DNA repair capacity and enhanced induction of apoptosis appear to be key factors in the sensitivity of germ cell tumors to cisplatin. Despite substantial cure rates, some patients relapse and subsequently die of their disease. Intensive doses of chemotherapy are used to counter mechanisms of drug resistance. So far, high-dose chemotherapy with hematopoietic stem cell support for solid tumors is used only in the setting of testicular germ cell tumors. In that indication, high-dose chemotherapy is given as the first or late salvage treatment for patients with either relapsed or progressive tumors after initial conventional salvage chemotherapy. High-dose chemotherapy is usually given as two or three sequential cycles using carboplatin and etoposide with or without ifosfamide. The administration of intensive therapy carries significant side effects and can only be efficiently and safely conducted in specialized referral centers to assure optimum patient care outcomes. In breast and ovarian cancer, most studies have demonstrated improvement in progression-free survival (PFS), but overall survival remained unchanged. Therefore, most of these approaches have been dropped. In germ cell tumors, clinical trials are currently investigating novel therapeutic combinations and active treatments. In particular, the integration of targeted therapies constitutes an important area of research for patients with a poor prognosis

  13. Germ cell development in larval and juvenile carp (Cyprinus carpio L.)

    NARCIS (Netherlands)

    Winkoop, van A.

    1995-01-01

    This thesis describes the development of larval and juvenile gonads of a teleost fish, the common carp, with special attention to the differentiation of the primordial germ cells. The early gonadal development has received relatively little attention, hitherto, as the research on fish

  14. Transcriptional Signatures in Response to Wheat Germ Agglutinin and Starvation in Drosophila melanogaster Larval Midgut

    Science.gov (United States)

    One function of plant lectins such as wheat germ agglutinin (WGA) is to serve as defenses against herbivorous insects. The midgut is one critical site affected by dietary lectins. We observed marked cellular, structural, and gene expression changes in the midguts of Drosophila melanogaster third-i...

  15. The effect of guar meal (germ fraction) and β-mannanase enzyme ...

    African Journals Online (AJOL)

    A completely randomized design experiment was conducted to assess the effect of β-mannanase enzyme on a commercial broiler chickens strain fed with different levels of guar meal germ fraction (GM) Each treatment was assigned to 4 replicate for a total of 24 pens, consisting of 15 chicks per pen, in randomized complete ...

  16. Wheat germ agglutinin-functionalised crosslinked polyelectrolyte microparticles for local colon delivery of 5-FU

    DEFF Research Database (Denmark)

    Glavas-Dodov,, Marija; Steffansen, Bente; Srcarevska, Maja

    2013-01-01

    We have previously reported the development and characterisation of wheat germ agglutinin (WGA)-functionalised chitosan-Ca-alginate (CTS-Ca-ALG) microparticles (MPs) loaded with acid-resistant particles of 5-fluorouracil (5-FU). In the present work, our goal was to evaluate the potential of these...

  17. Premeiotic germ cell defect in seminiferous tubules of Atm-null testis

    International Nuclear Information System (INIS)

    Takubo, Keiyo; Hirao, Atsushi; Ohmura, Masako; Azuma, Masaki; Arai, Fumio; Nagamatsu, Go; Suda, Toshio

    2006-01-01

    Lifelong spermatogenesis is maintained by coordinated sequential processes including self-renewal of stem cells, proliferation of spermatogonial cells, meiotic division, and spermiogenesis. It has been shown that ataxia telangiectasia-mutated (ATM) is required for meiotic division of the seminiferous tubules. Here, we show that, in addition to its role in meiosis, ATM has a pivotal role in premeiotic germ cell maintenance. ATM is activated in premeiotic spermatogonial cells and the Atm-null testis shows progressive degeneration. In Atm-null testicular cells, differing from bone marrow cells of Atm-null mice, reactive oxygen species-mediated p16 Ink4a activation does not occur in Atm-null premeiotic germ cells, which suggests the involvement of different signaling pathways from bone marrow defects. Although Atm-null bone marrow undergoes p16 Ink4a -mediated cellular senescence program, Atm-null premeiotic germ cells exhibited cell cycle arrest and apoptotic elimination of premeiotic germ cells, which is different from p16 Ink4a -mediated senescence

  18. Can serums be replaced by Mueller‑Hinton agar in germ tube test ...

    African Journals Online (AJOL)

    Background: The germ tube test (GTT) is inexpensive, easy, and well‑defined test that differentiates Candida albicans (excluding Candida dubliniensis and Candida africana) from other species. The aim of this study was to evaluate various serums (i.e., human, rabbit, horse, and fetal bovine serum) used in the GTT and ...

  19. Efficacy of wheat germ oil in modulating radiation-induced heart damage in rats

    International Nuclear Information System (INIS)

    Said, U.Z.; Azab, Kh.Sh.

    2006-01-01

    Wheat Germ oil is a natural unrefined vegetable oil. It is an excellent source of vitamin E, octacosanol, linoleic and linolenic essential fatty acids, which may be beneficial in neutralizing the free oxygen radicals. This study was designed to investigate the cardio-protective efficacy of wheat germ oil, on radiation-induced oxidative damage in rat's heart. Wheat germ oil was supplemented by gavage to rats at a dose of 81 mg/ kg body wt for 10 successive days pre- and 7 successive days post-exposure to 7 Gy (single dose) of whole body gamma irradiation. The dose of wheat germ oil is equivalent to daily human nutritional supplementation quantity. The results revealed that whole body ?-irradiation of rats produced significant alterations in blood cells picture. The erythrocyte, leucocyte, platelet counts and hemoglobin levels decreased after irradiation. Also, radiation-induced biochemical disorders manifested by significant elevation in xanthine oxidase activity (XO) and thiobarbituric acid reactive substances (TBARS) level, with decrease in reduced glutathione (GSH) content in heart tissues, indicating depression in the antioxidant status. Serum lipid profile as total cholesterol, high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C) and triglycerides levels (TG) were significantly higher than normal control rats. Radiation exposure produced a significant rise in the activities of serum markers for heart damage as creatine phosphokinase (CPK), aspartate aminotransferase (AST) and lactic dehydrogenase (LDH) indicating acute cardiac toxicity. Moreover, the obtained results revealed abnormal electrophoretic pattern of LDH isoenzymes in the 7th day after exposure to gamma rays. Three bands only appear on the agarose film comparing with 4 bands in normal control rats. The rats that received wheat germ oil supplement showed significantly less severe damage and remarkable improvement in all of the measured parameters when compared to

  20. MicroRNA biogenesis is required for mouse primordial germ cell development and spermatogenesis.

    Directory of Open Access Journals (Sweden)

    Katsuhiko Hayashi

    2008-03-01

    Full Text Available MicroRNAs (miRNAs are critical regulators of transcriptional and post-transcriptional gene silencing, which are involved in multiple developmental processes in many organisms. Apart from miRNAs, mouse germ cells express another type of small RNA, piwi-interacting RNAs (piRNAs. Although it has been clear that piRNAs play a role in repression of retrotransposons during spermatogenesis, the function of miRNA in mouse germ cells has been unclear.In this study, we first revealed the expression pattern of miRNAs by using a real-time PCR-based 220-plex miRNA expression profiling method. During development of germ cells, miR-17-92 cluster, which is thought to promote cell cycling, and the ES cell-specific cluster encoding miR-290 to -295 (miR-290-295 cluster were highly expressed in primordial germ cells (PGCs and spermatogonia. A set of miRNAs was developmentally regulated. We next analysed function of miRNA biogenesis in germ cell development by using conditional Dicer-knockout mice in which Dicer gene was deleted specifically in the germ cells. Dicer-deleted PGCs and spermatogonia exhibited poor proliferation. Retrotransposon activity was unexpectedly suppressed in Dicer-deleted PGCs, but not affected in the spermatogonia. In Dicer-deleted testis, spermatogenesis was retarded at an early stage when proliferation and/or early differentiation. Additionally, we analysed spermatogenesis in conditional Argonaute2-deficient mice. In contrast to Dicer-deficient testis, spermatogenesis in Argonaute2-deficient testis was indistinguishable from that in wild type.These results illustrate that miRNAs are important for the proliferation of PGCs and spermatogonia, but dispensable for the repression of retrotransposons in developing germ cells. Consistently, miRNAs promoting cell cycling are highly expressed in PGCs and spermatogonia. Furthermore, based on normal spermatogenesis in Argonaute2-deficient testis, the critical function of Dicer in spermatogenesis is

  1. In vitro generation and characterization of chicken long-term germ cells from different embryonic origins.

    Science.gov (United States)

    Raucci, Franca; Fuet, Aurelie; Pain, Bertrand

    2015-09-15

    Primordial germ cells (PGCs) are the precursors of differentiated germ cells. Located in the epiblast of a stage X (EG&K) embryo, the PGCs translocate anteriorly to the germinal crescent and migrate, within 48 to 56 hours of development, through the blood vascular system to the germinal ridges where they become the gonadal germ cells (GGCs). We aim to generate, compare, and determine the basic characters of the in vitro long-term cultured PGCs derived from (1) the chicken blastodermal cells (at stages IX-XII); (2) the chicken blood of a 2-day old embryo (stages 14-17 Hamburger Hamilton [HH]); and (3) the long-term cultured gonocytes taken from male gonads of a 5- to 6-day-old embryo (stages 29-30 HH). In presence of fibroblast growth factor, chicken blastodermal cells are able to long-term proliferate and generate small, round, alkaline phosphatase-positive cell clusters. Molecular characterization shows that these selected and amplified clusters show a PGC-like cell profile, as they express cPOUV (a pluripotent-associated marker), NR6A1/GCNF and DDX4/CVH (germ cell-specific genes). Both chicken PGCs and GGCs, obtained from embryonic blood and gonads, at 14 to 17 HH and 29 to 30 HH, respectively, generate long-term germ cell cultures and positively react in vitro to periodic acid-Schiff. Immunochemical analyses reveal that these cell lines are specifically recognized by anti-SSEA-1, anti-EMA-1, anti-CVH, anti-β1-integrin, and anti-CEACAM antibodies. The presence of surrounding cells may suggest a stronger dependency toward the niche process for the GGCs. The reactivity of chicken embryonic germ cells obtained from the two different sources to the specific markers used in this study was not altered through the culture. In conclusion, the morphologic analysis specific for chicken PGCs and GGCs will further contribute to quick and reliable characterization of long-term cultured in vitro chicken germ cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Opening up codings?

    DEFF Research Database (Denmark)

    Steensig, Jakob; Heinemann, Trine

    2015-01-01

    We welcome Tanya Stivers’s discussion (Stivers, 2015/this issue) of coding social interaction and find that her descriptions of the processes of coding open up important avenues for discussion, among other things of the precise ad hoc considerations that researchers need to bear in mind, both when...

  3. Error Correcting Codes -34 ...

    Indian Academy of Sciences (India)

    Science, Bangalore. Her interests are in. Theoretical Computer. Science. SERIES I ARTICLE. Error Correcting Codes. 2. The Hamming Codes. Priti Shankar. In the first article of this series we showed how redundancy introduced into a message transmitted over a noisy channel could improve the reliability of transmission. In.

  4. Decoding Codes on Graphs

    Indian Academy of Sciences (India)

    set up a well defined goal - that of achieving a per- formance bound set by the noisy channel coding theo- rem, proved in the paper. Whereas the goal appeared elusive twenty five years ago, today, there are practi- cal codes and decoding algorithms that come close to achieving it. It is interesting to note that all known.

  5. Error Correcting Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Error Correcting Codes - Reed Solomon Codes. Priti Shankar. Series Article Volume 2 Issue 3 March 1997 pp 33-47. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/03/0033-0047 ...

  6. Insurance billing and coding.

    Science.gov (United States)

    Napier, Rebecca H; Bruelheide, Lori S; Demann, Eric T K; Haug, Richard H

    2008-07-01

    The purpose of this article is to highlight the importance of understanding various numeric and alpha-numeric codes for accurately billing dental and medically related services to private pay or third-party insurance carriers. In the United States, common dental terminology (CDT) codes are most commonly used by dentists to submit claims, whereas current procedural terminology (CPT) and International Classification of Diseases, Ninth Revision, Clinical Modification (ICD.9.CM) codes are more commonly used by physicians to bill for their services. The CPT and ICD.9.CM coding systems complement each other in that CPT codes provide the procedure and service information and ICD.9.CM codes provide the reason or rationale for a particular procedure or service. These codes are more commonly used for "medical necessity" determinations, and general dentists and specialists who routinely perform care, including trauma-related care, biopsies, and dental treatment as a result of or in anticipation of a cancer-related treatment, are likely to use these codes. Claim submissions for care provided can be completed electronically or by means of paper forms.

  7. Codes of Conduct

    Science.gov (United States)

    Million, June

    2004-01-01

    Most schools have a code of conduct, pledge, or behavioral standards, set by the district or school board with the school community. In this article, the author features some schools that created a new vision of instilling code of conducts to students based on work quality, respect, safety and courtesy. She suggests that communicating the code…

  8. Decoding Codes on Graphs

    Indian Academy of Sciences (India)

    Department of Computer. Science 'and Automation,. lISe. Their research addresses ... The fifty five year old history of error correcting codes began with Claude Shannon's path-breaking paper en- titled 'A ... given the limited computing power available then, Gal- lager's codes were not considered practical. A landmark.

  9. Error Correcting Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Error Correcting Codes - Reed Solomon Codes. Priti Shankar. Series Article Volume 2 Issue 3 March ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India ...

  10. Decoding Codes on Graphs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 9. Decoding Codes on Graphs - Low Density Parity Check Codes. A S Madhu Aditya Nori. General Article Volume 8 Issue 9 September 2003 pp 49-59. Fulltext. Click here to view fulltext PDF. Permanent link:

  11. READING A NEURAL CODE

    NARCIS (Netherlands)

    BIALEK, W; RIEKE, F; VANSTEVENINCK, RRD; WARLAND, D

    1991-01-01

    Traditional approaches to neural coding characterize the encoding of known stimuli in average neural responses. Organisms face nearly the opposite task - extracting information about an unknown time-dependent stimulus from short segments of a spike train. Here the neural code was characterized from

  12. Effects of Lactobacillus kefiranofaciens M1 isolated from kefir grains on germ-free mice.

    Directory of Open Access Journals (Sweden)

    Yen-Po Chen

    Full Text Available Lactobacillus kefiranofaciens M1 is a novel probiotic strain that was isolated from kefir grains. Previously, we have demonstrated the immunoregulatory, anti-allergic, anti-asthmatic and anti-colitis abilities of L. kefiranofaciens M1 in a number of in-vitro and in-vivo experiments. However, whether the effects of L. kefiranofaciens M1 are elicited directly on the host or act by regulating the host's microbiota remains unknown. A number of studies have used germ-free or gnotobiotic animals to investigate the relationship between probiotics and colitis; therefore the aim of this study was to investigate the effects of L. kefiranofaciens M1 on germ-free mice. Such an approach should help in determining the direct effects of L. kefiranofaciens M1 on the host itself. Four-week-old female germ-free mice were inoculated intragastrically with 2×10(8 CFU/mouse L. kefiranofaciens M1 once or at 2-day intervals for 14 days. Bacterial colonization, the Th1/Th2 cytokine profile of the mice's splenocytes and the anti-colitis effect of L. kefiranofaciens M1 were investigated. The strongest response in terms of splenic Th1 cytokine IFN-γ and IL-12 production upon TLR activation was detected in the continuous treatment group when comparing to the single inoculation group and the germ-free control. In addition, continuous inoculation with L. kefiranofaciens M1 was found to ameliorate the symptoms of DSS-induced colitis in germ-free mice. However, L. kefiranofaciens M1 failed to colonize the host. Thus it would seem that L. kefiranofaciens M1 is likely to act directly on the host and not be involved in microbiota regulation.

  13. Wheat Germ Oil Attenuates Gamma Radiation- Induced Skeletal Muscles Damage in Rats

    International Nuclear Information System (INIS)

    Said, U.Z.; Saada, H.N.; Shedid, Sh.M.; Mahdy, E.M.E.; Shousha, W.Gh.

    2008-01-01

    Muscular strength is important in sport as well as in daily activities. Exposure to ionizing radiation is thought to increase oxidative stress and damage muscle tissue. Wheat germ oil is a natural unrefined vegetable oil. It is an excellent source of vitamin E, octacosanol, linoleic and linolenic essential fatty acids, which may be beneficial in neutralizing the free oxygen radicals. The present study was designed to investigate the efficacy of wheat germ oil, on radiation-induced oxidative damage in rats skeletal muscle. Wheat germ oil was supplemented orally via gavages to rats at a dose of 54 mg/ kg body weight/day for 14 successive days pre- and 7 post-exposure to 5 Gy (one shot dose) of whole body gamma irradiation. Animals were sacrificed 7, 14 and 21 days post radiation exposure. The results revealed that whole body gamma-irradiation of rats induces oxidative stress in skeletal muscles obvious by significant elevation in the level of thiobarbituric acid reactive substances (TBARS) associated with significant decreases in the content of reduced glutathione (GSE1), as well as decreases in superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities. Irradiated rats showed, also, significant decreases in creatine phosphokinase (CPK), glutamate dehydrogenase (GDH) and glucose-6-phosphate dehydrogenase (G-6-PD) activities. Furthermore, total iron, total copper and total calcium levels were significantly increased in skeletal muscles of irradiated rats group compared to control group. Wheat germ oil treated-irradiated rats showed significantly less sever damage and remarkable improvement in all the measured parameters, compared to irradiated rats. It could be concluded that wheat germ oil by attenuating radiation induced oxidative stress might play a role in maintaining skeletal muscle integrity

  14. Expression patterns and miRNA regulation of DNA methyltransferases in chicken primordial germ cells.

    Directory of Open Access Journals (Sweden)

    Deivendran Rengaraj

    Full Text Available DNA methylation is widespread in most species, from bacteria to mammals, and is crucial for genomic imprinting, gene expression, and embryogenesis. DNA methylation occurs via two major classes of enzymatic reactions: maintenance-type methylation catalyzed by DNA (cytosine-5--methyltransferase (DNMT 1, and de novo methylation catalyzed by DNMT 3 alpha (DNMT3A and -beta (DNMT3B. The expression pattern and regulation of DNMT genes in primordial germ cells (PGCs and germ line cells has not been sufficiently established in birds. Therefore, we employed bioinformatics, RT-PCR, real-time PCR, and in situ hybridization analyses to examine the structural conservation and conserved expression patterns of chicken DNMT family genes. We further examined the regulation of a candidate de novo DNA methyltransferase gene, cDNMT3B by cotransfection of cDNMT3B 3'UTR- and cDNMT3B 3'UTR-specific miRNAs through a dual fluorescence reporter assay. All cDNMT family members were differentially detected during early embryonic development. Of interest, cDNMT3B expression was highly detected in early embryos and in PGCs. During germ line development and sexual maturation, cDNMT3B expression was reestablished in a female germ cell-specific manner. In the dual fluorescence reporter assay, cDNMT3B expression was significantly downregulated by four miRNAs: gga-miR-15c (25.82%, gga-miR-29b (30.01%, gga-miR-383 (30.0%, and gga-miR-222 (31.28%. Our data highlight the structural conservation and conserved expression patterns of chicken DNMTs. The miRNAs investigated in this study may induce downregulation of gene expression in chicken PGCs and germ cells.

  15. The Formation and Migration of Primordial Germ Cells in Mouse and Man.

    Science.gov (United States)

    De Felici, Massimo

    In most multicellular organisms, including mammals, germ cells are at the origin of new organisms and ensure the continuation of the genetic and epigenetic information across the generations.In the mammalian germ line, the primordial germ cells (PGCs) are the precursors of the primary oocytes and prospermatogonia of fetal ovaries and testes, respectively. In mammals such as the primates, in which the formation of the primary oocytes is largely asynchronous and occurs during a relatively long period, PGCs after the arrival into the XX gonadal ridges are termed oogonia which then become primary oocytes when entering into meiotic prophase I. In the fetal testes, germ cells derived from the PGCs after gonad colonization are termed prospermatogonia or gonocytes.One of the most fascinating aspect of the mammalian germline development is that it is probably the first cell lineage to be established in the embryo by epigenetic mechanisms and that these inductive events happen in extraembryonic tissues much earlier that gonad develop inside the embryo proper. Moreover, such events prepare the germ cells for totipotency through genetic and epigenetic regulations of their genome function. How this occurs remained a mystery until short time ago.In this chapter, I will report and discuss the most recent advances in the cellular and molecular mechanisms underlying the formation in extraembryonic tissues and migration of PGCs toward the gonadal ridges made primarily by studies carried out in the mouse with some perspective in the human. Established concepts about these processes will be only summarized when necessary since they are widely described and discussed in many excellent reviews; most of them are cited in the text below.

  16. Germ cell specification and ovary structure in the rotifer Brachionus plicatilis

    Directory of Open Access Journals (Sweden)

    Smith James M

    2010-08-01

    Full Text Available Abstract Background The segregation of the germline from somatic tissues is an essential process in the development of all animals. Specification of the primordial germ cells (PGCs takes place via different strategies across animal phyla; either specified early in embryogenesis by the inheritance of maternal determinants in the cytoplasm of the oocyte ('preformation' or selected later in embryonic development from undifferentiated precursors by a localized inductive signal ('epigenesis'. Here we investigate the specification and development of the germ cells in the rotifer Brachionus plicatilis, a member of the poorly-characterized superphyla Lophotrochozoa, by isolating the Brachionus homologues of the conserved germ cell markers vasa and nanos, and examining their expression using in situ hybridization. Results Bpvasa and Bpnos RNA expression have very similar distributions in the Brachionus ovary, showing ubiquitous expression in the vitellarium, with higher levels in the putative germ cell cluster. Bpvas RNA expression is present in freshly laid eggs, remaining ubiquitous in embryos until at least the 96 cell stage after which expression narrows to a small cluster of cells at the putative posterior of the embryo, consistent with the developing ovary. Bpnos RNA expression is also present in just-laid eggs but expression is much reduced by the four-cell stage and absent by the 16-cell stage. Shortly before hatching of the juvenile rotifer from the egg, Bpnos RNA expression is re-activated, located in a subset of posterior cells similar to those expressing Bpvas at the same stage. Conclusions The observed expression of vasa and nanos in the developing B. plicatilis embryo implies an epigenetic origin of primordial germ cells in Rotifer.

  17. Retinoic acid induces differentiation of buffalo (Bubalus bubalis) embryonic stem cells into germ cells.

    Science.gov (United States)

    Shah, Syed Mohmad; Singla, Suresh Kumar; Palta, Prabhat; Manik, Radhey Sham; Chauhan, Manmohan Singh

    2017-08-30

    Development of precise and reproducible culture system for in vitro differentiation of embryonic stem (ES) cells into germ cells counts as a major leap forward for understanding not only the remarkable process of gametogenesis, otherwise obscured by limited availability of precursor primordial germ cells (PGCs), but in finally treating the catastrophic infertility. Taking into account the significant role of retinoic acid (RA) during in vivo gametogenesis, we designed the present study to investigate the effects of its stimulation on directing the differentiation of ES cells into germ cells. The effects of RA were analyzed across dose-and-time upon various stages of gametogenesis like PGC induction, meiosis initiation and completion, haploid cell formation and development of the final gamete (oocyte and spermatozoa). Out of the series of RA doses (2, 4, 8, 16, 20 and 30μM), 16μM RA for 8day culture interval was found to induce highest expression of PGC- and meiosis-associated genes like DAZL, VASA, SYCP3, MLH1, TNP1/2 and PRM2, while mature germ cell genes like BOULE and TEKT1 (Spermatocyte markers), GDF9 and ZP2 (Oocyte markers) showed higher expression at 2μM RA dose, suggesting functional concentration-gradient of RA activity. Immunocytochemistry revealed expression of germ lineage-specific markers like: c-KIT, DAZL and VASA (PGC-markers); SYCP3, MLH1 and PROTAMINE1 (Meiotic-markers); ACROSIN and HAPRIN (Spermatocyte-markers); and GDF9 and ZP4 (Oocyte-markers) in optimally differentiated embryoid bodies (EBs) and adherent cultures. We observed significantly reduced (pcell population, indicating completion of meiosis. Oocyte-like structures (OLS) were obtained in adherent differentiated cultures. They had a big nucleus and a zona pellucida (ZP4) coat. They showed progression through 2-cell, 4-cell, 8-cell, morula and blastocyst-like structures upon extended culture beyond 14days. Copyright © 2017. Published by Elsevier B.V.

  18. Molecular Evolution of Two Distinct dmrt1 Promoters for Germ and Somatic Cells in Vertebrate Gonads.

    Science.gov (United States)

    Mawaribuchi, Shuuji; Musashijima, Masato; Wada, Mikako; Izutsu, Yumi; Kurakata, Erina; Park, Min Kyun; Takamatsu, Nobuhiko; Ito, Michihiko

    2017-03-01

    The transcription factor DMRT1 has important functions in two distinct processes, somatic-cell masculinization and germ-cell development in mammals. However, it is unknown whether the functions are conserved during evolution, and what mechanism underlies its expression in the two cell lineages. Our analysis of the Xenopus laevis and Silurana tropicalis dmrt1 genes indicated the presence of two distinct promoters: one upstream of the noncoding first exon (ncEx1), and one within the first intron. In contrast, only the ncEx1-upstream promoter was detected in the dmrt1 gene of the agnathan sand lamprey, which expressed dmrt1 exclusively in the germ cells. In X. laevis, the ncEx1- and exon 2-upstream promoters were predominantly used for germ-cell and somatic-cell transcription, respectively. Importantly, knockdown of the ncEx1-containing transcript led to reduced germ-cell numbers in X. laevis gonads. Intriguingly, two genetically female individuals carrying the knockdown construct developed testicles. Analysis of the reptilian leopard gecko dmrt1 revealed the absence of ncEx1. We propose that dmrt1 regulated germ-cell development in the vertebrate ancestor, then acquired another promoter in its first intron to regulate somatic-cell masculinization during gnathostome evolution. In the common ancestor of reptiles and mammals, only one promoter got function for both the two cell lineages, accompanied with the loss of ncEx1. In addition, we found a conserved noncoding sequence (CNS) in the dmrt1 5'-flanking regions only among amniote species, and two CNSs in the introns among most vertebrates except for agnathans. Finally, we discuss relationships between these CNSs and the promoters of dmrt1 during vertebrate evolution. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Propagation of human germ stem cells in long-term culture

    Science.gov (United States)

    Akhondi, Mohammad Mehdi; Mohazzab, Arash; Jeddi-Tehrani, Mahmood; Sadeghi, Mohammad Reza; Eidi, Akram; Khodadadi, Abbas; Piravar, Zeinab

    2013-01-01

    Background: Spermatogonial stem cells (SSCs), a subset of undifferentiated type A spermatogonia, are the foundation of complex process of spermatogenesis and could be propagated in vitro culture conditions for long time for germ cell transplantation and fertility preservation. Objective: The aim of this study was in vitro propagation of human spermatogonial stem cells (SSCs) and improvement of presence of human Germ Stem Cells (hGSCs) were assessed by specific markers POU domain, class 5, transcription factor 1 (POU5F1), also known as Octamer-binding transcription factor 4 (Oct-4) and PLZF (Promyelocytic leukaemia zinc finger protein). Materials and Methods: Human testicular cells were isolated by enzymatic digestion (Collagenase IV and Trypsin). Germ cells were cultured in Stem-Pro 34 media supplemented by growth factors such as glial cell line-derived neurotrophic factor, basic fibroblast growth factor, epidermal growth factor and leukemia inhibitory factor to support self-renewal divisions. Germline stem cell clusters were passaged and expanded every week. Immunofluorecent study was accomplished by Anti-Oct4 antibody through the culture. The spermatogonial stem cells genes expression, PLZF, was studied in testis tissue and germ stem cells entire the culture. Results: hGSCs clusters from a brain dead patient developed in testicular cell culture and then cultured and propagated up to 6 weeks. During the culture Oct4 were a specific marker for identification of hGSCs in testis tissue. Expression of PLZF was applied on RNA level in germ stem cells. Conclusion: hGSCs indicated by SSCs specific marker can be cultured and propagated for long-term in vitro conditions. This article extracted from Ph.D. Thesis. (Zeinab Piravar) PMID:24639790

  20. Expression and knockdown analysis of glucose phosphate isomerase in chicken primordial germ cells.

    Science.gov (United States)

    Rengaraj, Deivendran; Lee, Sang In; Yoo, Min; Kim, Tae Hyun; Song, Gwonhwa; Han, Jae Yong

    2012-09-01

    Glucose is an important monosaccharide required to generate energy in all cells. After entry into cells, glucose is phosphorylated to glucose-6-phosphate and then transformed into glycogen or metabolized to produce energy. Glucose phosphate isomerase (GPI) catalyzes the reversible isomerization of glucose-6-phosphate and fructose-6-phosphate. Without GPI activity or fructose-6-phosphate, many steps of glucose metabolism would not occur. The requirement for GPI activity for normal functioning of primordial germ cells (PGCs) needs to be identified. In this study, we first examined the expression of chicken GPI during early embryonic development and germ cell development. GPI expression was strongly and ubiquitously detected in chicken early embryos and embryonic tissues at Embryonic Day 6.5 (E6.5). Continuous GPI expression was detected in PGCs and germ cells of both sexes during gonadal development. Specifically, GPI expression was stronger in male germ cells than in female germ cells during embryonic development and the majority of post-hatching development. Then, we used siRNA-1499 to knock down GPI expression in PGCs. siRNA-1499 caused an 85% knockdown in GPI, and PGC proliferation was also affected 48 h after transfection. We further examined the knockdown effects on 28 genes related to the glycolysis/gluconeogenesis pathway and the endogenous glucose level in chicken PGCs. Among genes related to glycolysis/gluconeogenesis, 20 genes showed approximately 3-fold lower expression, 4 showed approximately 10-fold lower, and 2 showed approximately 100-fold lower expression in knockdown PGCs. The endogenous glucose level was significantly reduced in knockdown PGCs. We conclude that the GPI gene is crucial for maintaining glycolysis and supplying energy to developing PGCs.

  1. Impaired germ cell development due to compromised cell cycle progression in Skp2-deficient mice

    Directory of Open Access Journals (Sweden)

    Nakayama Keiko

    2006-04-01

    Full Text Available Abstract Background The gonads are responsible for the production of germ cells through both mitosis and meiosis. Skp2 is the receptor subunit of an SCF-type ubiquitin ligase and is a major regulator of the progression of cells into S phase of the cell cycle, which it promotes by mediating the ubiquitin-dependent degradation of p27, an inhibitor of cell proliferation. However, the role of the Skp2-p27 pathway in germ cell development remains elusive. Results We now show that disruption of Skp2 in mice results in a marked impairment in the fertility of males, with the phenotypes resembling Sertoli cell-only syndrome in men. Testes of Skp2-/- mice manifested pronounced germ cell hypoplasia accompanied by massive apoptosis in spermatogenic cells. Flow cytometry revealed an increased prevalence of polyploidy in spermatozoa, suggesting that the aneuploidy of these cells is responsible for the induction of apoptosis. Disruption of the p27 gene of Skp2-/- mice restored germ cell development, indicating that the testicular hypoplasia of Skp2-/- animals is attributable to the antiproliferative effect of p27 accumulation. Conclusion Our results thus suggest that compromised cell cycle progression caused by the accumulation of p27 results in aneuploidy and the induction of apoptosis in gonadal cells of Skp2-/- mice. The consequent reduction in the number of mature gametes accounts for the decreased fertility of these animals. These findings reinforce the importance of the Skp2-p27 pathway in cell cycle regulation and in germ cell development.

  2. Fracture flow code

    International Nuclear Information System (INIS)

    Dershowitz, W; Herbert, A.; Long, J.

    1989-03-01

    The hydrology of the SCV site will be modelled utilizing discrete fracture flow models. These models are complex, and can not be fully cerified by comparison to analytical solutions. The best approach for verification of these codes is therefore cross-verification between different codes. This is complicated by the variation in assumptions and solution techniques utilized in different codes. Cross-verification procedures are defined which allow comparison of the codes developed by Harwell Laboratory, Lawrence Berkeley Laboratory, and Golder Associates Inc. Six cross-verification datasets are defined for deterministic and stochastic verification of geometric and flow features of the codes. Additional datasets for verification of transport features will be documented in a future report. (13 figs., 7 tabs., 10 refs.) (authors)

  3. Validation of thermalhydraulic codes

    International Nuclear Information System (INIS)

    Wilkie, D.

    1992-01-01

    Thermalhydraulic codes require to be validated against experimental data collected over a wide range of situations if they are to be relied upon. A good example is provided by the nuclear industry where codes are used for safety studies and for determining operating conditions. Errors in the codes could lead to financial penalties, to the incorrect estimation of the consequences of accidents and even to the accidents themselves. Comparison between prediction and experiment is often described qualitatively or in approximate terms, e.g. ''agreement is within 10%''. A quantitative method is preferable, especially when several competing codes are available. The codes can then be ranked in order of merit. Such a method is described. (Author)

  4. The ligand binding domain of GCNF is not required for repression of pluripotency genes in mouse fetal ovarian germ cells.

    Directory of Open Access Journals (Sweden)

    Leah M Okumura

    Full Text Available In mice, successful development and reproduction require that all cells, including germ cells, transition from a pluripotent to a differentiated state. This transition is associated with silencing of the pluripotency genes Oct4 and Nanog. Interestingly, these genes are repressed at different developmental timepoints in germ and somatic cells. Ovarian germ cells maintain their expression until about embryonic day (E 14.5, whereas somatic cells silence them much earlier, at about E8.0. In both somatic cells and embryonic stem cells, silencing of Oct4 and Nanog requires the nuclear receptor GCNF. However, expression of the Gcnf gene has not been investigated in fetal ovarian germ cells, and whether it is required for silencing Oct4 and Nanog in that context is not known. Here we demonstrate that Gcnf is expressed in fetal ovarian germ cells, peaking at E14.5, when Oct4 and Nanog are silenced. However, conditional ablation of the ligand-binding domain of Gcnf using a ubiquitous, tamoxifen-inducible Cre indicates that Gcnf is not required for the down-regulation of pluripotency genes in fetal ovarian germ cells, nor is it required for initiation of meiosis and oogenesis. These results suggest that the silencing of Oct4 and Nanog in germ cells occurs via a different mechanism from that operating in somatic cells during gastrulation.

  5. Comparison between the effect of γ-irradiation and roasting on the profile and antioxidant activity of wheat germ lipids

    International Nuclear Information System (INIS)

    Ramadan, M.F.; El-Said Showky, H.; Abd el Rahman, M.S.

    2008-01-01

    In order to utilize wheat germ, a nutrient-dense byproduct of the wheat milling industry, in various food products, different treatments are used to investigate and stabilize its influence on lipid characteristics. However, there are no reports on the effect of gamma-irradiation on the lipid profile of wheat germ. In this study, the impact of gamma-irradiation (at radiation doses 1/4, 1/2 and 1 kGy) and roasting at (160 deg C for 20 min) on the lipid constituents of wheat germ was examined. Both thermal and irradiation treatments did not have a significant effect on the total lipid recovery or the fatty acid composition of wheat germ lipids. The fatty acid profile was found to be made up of linoleic followed by oleic and palmitic as the major fatty acids. An increase in the content of free fatty acids characterized the lipid profile of the irradiated wheat germ samples. Antiradical properties of lipids from roasted and irradiated samples were analyzed using the bleaching of the stable 1,1-diphenyl-2- picrylhydrazyl radical (DPPH). Lipids from irradiated samples exhibited relatively stronger radical scavenging potential than lipids from roasted wheat germ. It has been concluded that gamma-irradiation could be applied for wheat germ preservation, where it might be limited to a dose of 1/4 kGy in the processing

  6. Report number codes

    International Nuclear Information System (INIS)

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name

  7. Report number codes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.N. (ed.)

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  8. Germs of local automorphisms of real analytic CR structures and analytic dependence on the k-jets

    OpenAIRE

    ZAITSEV, DMITRI

    1997-01-01

    PUBLISHED The topic of the paper is the study of germs of local holomorphisms f between Cn and Cn ? such that f(M) #26; M? and df(TcM) = TcM? for M #26; Cn and M? #26; Cn ? generic real-analytic CR submanifolds of arbitrary codimensions. It is proved that for M minimal and M? finitely nondegenerate, such germs depend analytically on their jets. As a corollary, an analytic structure on the set of all germs of this type is obtained.

  9. Laser propagation code study

    OpenAIRE

    Rockower, Edward B.

    1985-01-01

    A number of laser propagation codes have been assessed as to their suitability for modeling Army High Energy Laser (HEL) weapons used in an anti- sensor mode. We identify a number of areas in which systems analysis HEL codes are deficient. Most notably, available HEL scaling law codes model the laser aperture as circular, possibly with a fixed (e.g. 10%) obscuration. However, most HELs have rectangular apertures with up to 30% obscuration. We present a beam-quality/aperture shape scaling rela...

  10. Transport theory and codes

    International Nuclear Information System (INIS)

    Clancy, B.E.

    1986-01-01

    This chapter begins with a neutron transport equation which includes the one dimensional plane geometry problems, the one dimensional spherical geometry problems, and numerical solutions. The section on the ANISN code and its look-alikes covers problems which can be solved; eigenvalue problems; outer iteration loop; inner iteration loop; and finite difference solution procedures. The input and output data for ANISN is also discussed. Two dimensional problems such as the DOT code are given. Finally, an overview of the Monte-Carlo methods and codes are elaborated on

  11. Gravity inversion code

    International Nuclear Information System (INIS)

    Burkhard, N.R.

    1979-01-01

    The gravity inversion code applies stabilized linear inverse theory to determine the topography of a subsurface density anomaly from Bouguer gravity data. The gravity inversion program consists of four source codes: SEARCH, TREND, INVERT, and AVERAGE. TREND and INVERT are used iteratively to converge on a solution. SEARCH forms the input gravity data files for Nevada Test Site data. AVERAGE performs a covariance analysis on the solution. This document describes the necessary input files and the proper operation of the code. 2 figures, 2 tables

  12. Decoding the productivity code

    DEFF Research Database (Denmark)

    Hansen, David

    , that is, the productivity code of the 21st century, is dissolved. Today, organizations are pressured for operational efficiency, often in terms of productivity, due to increased global competition, demographical changes, and use of natural resources. Taylor’s principles for rationalization founded...... that swing between rationalization and employee development. The productivity code is the lack of alternatives to this ineffective approach. This thesis decodes the productivity code based on the results from a 3-year action research study at a medium-sized manufacturing facility. During the project period...

  13. CALIPSOS code report

    International Nuclear Information System (INIS)

    Fanselau, R.W.; Thakkar, J.G.; Hiestand, J.W.; Cassell, D.S.

    1980-04-01

    CALIPSOS is a steady-state three-dimensional flow distribution code which predicts the fluid dynamics and heat transfer interactions of the secondary two-phase flow in a steam generator. The mathematical formulation is sufficiently general to accommodate two fluid models described by separate gas and liquid momentum equations. However, if the user selects the homogeneous flow option, the code automatically equates the gas and liquid phase velocities (thereby reducing the number of momentum equations solved to three) and utilizes a homogeneous density mixture. This report presents the basic features of the CALIPSOS code and includes assumptions, equations solved, the finite-difference grid, and highlights of the solution procedure

  14. Cryptography cracking codes

    CERN Document Server

    2014-01-01

    While cracking a code might seem like something few of us would encounter in our daily lives, it is actually far more prevalent than we may realize. Anyone who has had personal information taken because of a hacked email account can understand the need for cryptography and the importance of encryption-essentially the need to code information to keep it safe. This detailed volume examines the logic and science behind various ciphers, their real world uses, how codes can be broken, and the use of technology in this oft-overlooked field.

  15. Basic fibroblast growth factor is critical to reprogramming buffalo (Bubalus bubalis) primordial germ cells into embryonic germ stem cell-like cells.

    Science.gov (United States)

    Wang, Caizhu; Deng, Yanfei; Chen, Feng; Zhu, Peng; Wei, Jingwei; Luo, Chan; Lu, Fenghua; Yang, Sufang; Shi, Deshun

    2017-03-15

    Primordial germ cells (PGCs) are destined to form gametes in vivo, and they can be reprogrammed into pluripotent embryonic germ (EG) cells in vitro. Buffalo PGC have been reported to be reprogrammed into EG-like cells, but the identities of the major signaling pathways and culture media involved in this derivation remain unclear. Here, the effects of basic fibroblast growth factor (bFGF) and downstream signaling pathways on the reprogramming of buffalo PGCs into EG-like cells were investigated. Results showed bFGF to be critical to buffalo PGCs to dedifferentiate into EG-like cells (20 ng/mL is optimal) with many characteristics of pluripotent stem cells, including alkaline phosphatase (AP) activity, expression of pluripotency marker genes such as OCT4, NANOG, SOX2, SSEA-1, CDH1, and TRA-1-81, and the capacity to differentiate into all three embryonic germ layers. After chemically inhibiting pathways or components downstream of bFGF, data showed that inhibition of the PI3K/AKT pathway led to significantly lower EG cell derivation, while inhibition of P53 activity resulted in an efficiency of EG cell derivation comparable to that in the presence of bFGF. These results suggest that the role of bFGF in PGC-derived EG-like cell generation is mainly due to the activation of the PI3K/AKT/P53 pathway, in particular, the inhibition of P53 function. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Avaliação da atividade antioxidante do ácido fítico de germe de milho Corn germ phytic acid antioxidant activity evaluation

    Directory of Open Access Journals (Sweden)

    Cristina Tostes Filgueiras

    2009-01-01

    Full Text Available The obtained corn germ phytic acid (CGPA antioxidant potential was evaluated through the deoxyribose, bathophenanthroline (BPS and DPPH• assays. In the concentration of 130.5 μM of CGPA the hydroxyl radical maximum sequestering antioxidant activity was 29.3% while standard phytic acid (SPA presented this maximum activity of 18.2% in the concentration of 33.2 μM of SPA. The BPS assays revealed that the chelation activity towards Fe2+ increased concurrently with the increase of CGPA concentration and its Fe2+ contact time. Finally, DPPH• assay showed that CGPA and SPA did not present electron-donating capacity to DPPH•.

  17. Membrane-bound steel factor maintains a high local concentration for mouse primordial germ cell motility, and defines the region of their migration.

    Directory of Open Access Journals (Sweden)

    Ying Gu

    Full Text Available Steel factor, the protein product of the Steel locus in the mouse, is a multifunctional signal for the primordial germ cell population. We have shown previously that its expression accompanies the germ cells during migration to the gonads, forming a "travelling niche" that controls their survival, motility, and proliferation. Here we show that these functions are distributed between the alternatively spliced membrane-bound and soluble forms of Steel factor. The germ cells normally migrate as individuals from E7.5 to E11.5, when they aggregate together in the embryonic gonads. Movie analysis of Steel-dickie mutant embryos, which make only the soluble form, at E7.5, showed that the germ cells fail to migrate normally, and undergo "premature aggregation" in the base of the allantois. Survival and directionality of movement is not affected. Addition of excess soluble Steel factor to Steel-dickie embryos rescued germ cell motility, and addition of Steel factor to germ cells in vitro showed that a fourfold higher dose was required to increase motility, compared to survival. These data show that soluble Steel factor is sufficient for germ cell survival, and suggest that the membrane-bound form provides a higher local concentration of Steel factor that controls the balance between germ cell motility and aggregation. This hypothesis was tested by addition of excess soluble Steel factor to slice cultures of E11.5 embryos, when migration usually ceases, and the germ cells aggregate. This reversed the aggregation process, and caused increased motility of the germ cells. We conclude that the two forms of Steel factor control different aspects of germ cell behavior, and that membrane-bound Steel factor controls germ cell motility within a "motility niche" that moves through the embryo with the germ cells. Escape from this niche causes cessation of motility and death by apoptosis of the ectopic germ cells.

  18. Diversification and germ-line determination revisited: Linking developmental mechanism with species richness

    Directory of Open Access Journals (Sweden)

    Brian I Crother

    2016-03-01

    Full Text Available Abstract.– Background: Explanations for asymmetric patterns of diversification continue to challenge paleontologists and neontologists with competing hypotheses within genetic-development and ecological frameworks. In 1988, a hypothesis was proposed that tied a primordial germ cell (PGC determination mechanism to clade (phyla diversification. Two general mechanisms for PGC determination are recognized: one is termed induced because induction signals are required for the production of primordial germ cells. The other mechanism is cell-autonomous, i.e. determinative, because the cells that develop in response to specific cytoplasmic determinants in the oocyte are pre-destined to become PGCs. We revisited the hypothesis and analyzed phyla diversity with germ cell determination mechanisms and examined sister clade asymmetry.Results: After 25 years of additional data accumulation, the hypothesis that high levels of species diversification are associated with the induced mode is falsified, with the determinative mode revealed as associated with higher rates of diversification. The greater species numbers are significantly associated (ANOVA p>0.003 with the determinative mode. Analysis with appropriate sister clades is unanimous in showing the clade with the determinative mode has a significantly greater number of species relative to its induced sister clade .Conclusions: The primordial germ cell determination mechanism hypothesis explains asymmetrical species diversity and morphological disparity at the phylum level. We argue that the determinative mode of primordial germ cell determination is a constraint release that has enhanced evolvability and increased rates of speciation and morphological disparity among clades. Knowledge of the mechanism for extant theropods allows speculation that its sister clade, the Sauropodomorpha would have exhibited the induced mode.Results: After 25 years of additional data accumulation, the hypothesis that high

  19. The fast code

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, L.N.; Wilson, R.E. [Oregon State Univ., Dept. of Mechanical Engineering, Corvallis, OR (United States)

    1996-09-01

    The FAST Code which is capable of determining structural loads on a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees of freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting, occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good. (au)

  20. Fulcrum Network Codes

    DEFF Research Database (Denmark)

    2015-01-01

    Fulcrum network codes, which are a network coding framework, achieve three objectives: (i) to reduce the overhead per coded packet to almost 1 bit per source packet; (ii) to operate the network using only low field size operations at intermediate nodes, dramatically reducing complexity...... in the network; and (iii) to deliver an end-to-end performance that is close to that of a high field size network coding system for high-end receivers while simultaneously catering to low-end ones that can only decode in a lower field size. Sources may encode using a high field size expansion to increase...... the number of dimensions seen by the network using a linear mapping. Receivers can tradeoff computational effort with network delay, decoding in the high field size, the low field size, or a combination thereof....