Induction of human umbilical Wharton's jelly-derived mesenchymal stem cells toward motor neuron-like cells.

PubMed

Bagher, Zohreh; Ebrahimi-Barough, Somayeh; Azami, Mahmoud; Mirzadeh, Hamid; Soleimani, Mansooreh; Ai, Jafar; Nourani, Mohammad Reza; Joghataei, Mohammad Taghi

2015-10-01

The most important property of stem cells from different sources is the capacity to differentiate into various cells and tissue types. However, problems including contamination, normal karyotype, and ethical issues cause many limitations in obtaining and using these cells from different sources. The cells in Wharton's jelly region of umbilical cord represent a pool source of primitive cells with properties of mesenchymal stem cells (MSCs). The aim of this study was to determine the potential of human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) for differentiation to motor neuron cells. WJMSCs were induced to differentiate into motor neuron-like cells by using different signaling molecules and neurotrophic factors in vitro. Differentiated neurons were then characterized for expression of motor neuron markers including nestin, PAX6, NF-H, Islet 1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription PCR and immunocytochemistry. Our results showed that differentiated WJMSCs could significantly express motor neuron biomarkers in RNA and protein levels 15 d post induction. These results suggested that WJMSCs can differentiate to motor neuron-like cells and might provide a potential source in cell therapy for neurodegenerative disease.

Purification of zebrafish erythrocytes as a means of identifying a novel regulator of haematopoiesis.

PubMed

Kulkeaw, Kasem; Inoue, Tomoko; Ishitani, Tohru; Nakanishi, Yoichi; Zon, Leonard I; Sugiyama, Daisuke

2018-02-01

Zebrafish embryos are useful to study haematopoietic gene function in vertebrates, although lack of antibodies to zebrafish proteins has limited the purification of specific cell populations. Here, we purified primitive zebrafish erythrocytes using 1, 5-bis{[2-(di-methylamino)ethyl]amino}-4, 8-dihydroxyanthracene-9, 10-dione (DRAQ5 TM ), a DNA-staining fluorescent dye. At 48-h post-fertilization, we sorted small-sized cells from embryos using forward scatter and found that they consisted of DRAQ5 high and DRAQ5 low populations. DRAQ5 high cells contained haemoglobin, lacked myeloperoxidase activity and expressed high levels of embryonic globin (hbae3 and hbbe1.1) mRNA, all characteristics of primitive erythrocytes. Following DRAQ5 TM analysis of gata1:dsRed transgenic embryos, we purified primitive DRAQ5 high dsRed+ erythrocytes from haematopoietic progenitor cells. Using this method, we identified docking protein 2 (Dok2) as functioning in differentiation of primitive erythrocytes. We conclude that DRAQ5 TM -based flow cytometry enables purification of primitive zebrafish erythrocytes. © 2017 John Wiley & Sons Ltd.

Therapeutic Trial for Patients With Ewing Sarcoma Family of Tumor and Desmoplastic Small Round Cell Tumors

ClinicalTrials.gov

2017-09-18

Desmoplastic Small Round Cell Tumor; Ewing Sarcoma of Bone or Soft Tissue; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Geochemical characteristics of the La Réunion mantle plume source inferred from olivine-hosted melt inclusions from the adventive cones of Piton de la Fournaise volcano (La Réunion Island)

NASA Astrophysics Data System (ADS)

Valer, Marina; Schiano, Pierre; Bachèlery, Patrick

2017-09-01

Major and trace element compositions were obtained for bulk rocks and melt inclusions hosted in olivine crystals (Fo > 85) from the adventive cones of the Piton de La Fournaise volcano (La Réunion Island). Ratios of highly incompatible trace elements for these magmas are used to identify the nature of the La Réunion mantle plume source. Although adventive cone lavas display unusual major element compositions compared to the historical lavas of the volcano (e.g., lower CaO/Al2O3), trace element data suggest that the magmas emitted by the adventive cones originate from a common chemical source. This source may correspond to either a homogeneous mixed source of different mantle components or a near-primitive less-differentiated mantle source. The melt inclusions display ratios of highly incompatible elements (e.g., Th/La, Nb/La) which are similar to primitive mantle values, and lower Nb/U ratios compared to most oceanic basalts. These results and previous isotopic and trace element data suggest that La Réunion plume samples a source which is intermediate between a primitive-like mantle domain and a slightly depleted one almost unaffected by the recycling processes. This source could have originated from early depletion of the primitive mantle. Assuming a depletion 4.45 Gyr ago, 10% melting of this slightly depleted source could explain the enriched trace element concentrations of the melt inclusions.

Clonal analysis identifies hemogenic endothelium as the source of the blood-endothelial common lineage in the mouse embryo

PubMed Central

Padrón-Barthe, Laura; Temiño, Susana; Villa del Campo, Cristina; Carramolino, Laura; Isern, Joan

2014-01-01

The first blood and endothelial cells of amniote embryos appear in close association in the blood islands of the yolk sac (YS). This association and in vitro lineage analyses have suggested a common origin from mesodermal precursors called hemangioblasts, specified in the primitive streak during gastrulation. Fate mapping and chimera studies, however, failed to provide strong evidence for a common origin in the early mouse YS. Additional in vitro studies suggest instead that mesodermal precursors first generate hemogenic endothelium, which then generate blood cells in a linear sequence. We conducted an in vivo clonal analysis to determine the potential of individual cells in the mouse epiblast, primitive streak, and early YS. We found that early YS blood and endothelial lineages mostly derive from independent epiblast populations, specified before gastrulation. Additionally, a subpopulation of the YS endothelium has hemogenic activity and displays characteristics similar to those found later in the embryonic hemogenic endothelium. Our results show that the earliest blood and endothelial cell populations in the mouse embryo are specified independently, and that hemogenic endothelium first appears in the YS and produces blood precursors with markers related to definitive hematopoiesis. PMID:25139355

Bone marrow-on-a-chip: Long-term culture of human haematopoietic stem cells in a three-dimensional microfluidic environment.

PubMed

Sieber, Stefan; Wirth, Lorenz; Cavak, Nino; Koenigsmark, Marielle; Marx, Uwe; Lauster, Roland; Rosowski, Mark

2018-02-01

Multipotent haematopoietic stem and progenitor cells (HSPCs) are the source for all blood cell types. The bone marrow stem cell niche in which the HSPCs are maintained is known to be vital for their maintenance. Unfortunately, to date, no in vitro model exists that accurately mimics the aspects of the bone marrow niche and simultaneously allows the long-term culture of HSPCs. In this study, a novel three-dimensional coculture model is presented, based on a hydroxyapatite coated zirconium oxide scaffold, comprising of human mesenchymal stromal cells (MSCs) and cord blood derived HSPCs, enabling successful HSPC culture for a time span of 28 days within the microfluidic multiorgan chip. The HSPCs were found to stay in their primitive state (CD34 + CD38 - ) and capable of granulocyte, erythrocyte, macrophage, megakaryocyte colony formation. Furthermore, a microenvironment was formed bearing molecular and structural similarity to the in vivo bone marrow niche containing extracellular matrix and signalling molecules known to play an important role in HSPC homeostasis. Here, a novel human in vitro bone marrow model is presented for the first time, capable of long-term culture of primitive HSPCs in a microfluidic environment. Copyright © 2017 John Wiley & Sons, Ltd.

The effect of Bcr-Abl protein tyrosine kinase on maturation and proliferation of primitive haematopoietic cells.

PubMed Central

Buckle, A. M.; Mottram, R.; Pierce, A.; Lucas, G. S.; Russell, N.; Miyan, J. A.; Whetton, A. D.

2000-01-01

BACKGROUND: Chronic Myeloid Leukaemia (CML) is characterised by the chromosomal translocation resulting in expression of the Bcr-Abl protein tyrosine kinase (PTK) in early stem cells and their progeny. However the precise nature of Bcr-Abl effects in primitive CML stem cells remains a matter of active debate. MATERIALS AND METHODS: Extremely primitive Bcr-Abl fusion positive cells were purified from patients with CML using multiparameter flow cytometric analysis of CD34, Thy, and lineage marker (Lin) expression, plus rhodamine-123 (Rh-123) brightness. Progenitor cells of increasing maturity were examined for cycling status by flow cytometry and their proliferative status directly correlated with cell phenotype. The activation status of a key transcription factor, signal transducers and activators of transcription (STAT-5), was also analyzed by immunocytochemistry. RESULTS: The most primitive stem cells currently defined (CD34+Lin-Thy+ Rh-1231o) were present as a lower proportion of the stem cell compartment (CD34+Lin-) of CML patients at presentation than of normal individuals (2.3% +/- 0.4 compared with 5.1% +/- 0.6 respectively). Conversely there was a significantly higher proportion of the more mature cells (CD34+Lin-Thy-Rh-123 hi) in CML patients than in normal individuals (79.3 +/- 1.8 compared with 70.9 +/- 3.3). No primitive subpopulation of CML CD34+Lin- cells was cycling to a significantly greater degree than cells from normal donors, in fact, late progenitor cells (CD34+Lin+) were cycling significantly less in CML samples than normal samples. STAT5, however, was observed to be activated in CML cells. CONCLUSIONS: We conclude that no subpopulation of CML stem cells displays significantly increased cell cycling. Thus, increased cycling cannot be a direct consequence of Bcr-Abl PTK acquisition in highly enriched stem cells from patients with CML. In vivo CML need not be considered a disease of unbridled stem cell proliferation, but a subtle defect in the balance between self renewal and maturation. PMID:11126203

Primitive Sca-1 Positive Bone Marrow HSC in Mouse Model of Aplastic Anemia: A Comparative Study through Flowcytometric Analysis and Scanning Electron Microscopy

PubMed Central

Chatterjee, Sumanta; Basak, Pratima; Das, Prosun; Das, Madhurima; Pereira, Jacintha Archana; Dutta, Ranjan Kumar; Chaklader, Malay; Chaudhuri, Samaresh; Law, Sujata

2010-01-01

Self-renewing Hematopoietic Stem Cells (HSCs) are responsible for reconstitution of all blood cell lineages. Sca-1 is the “stem cell antigen” marker used to identify the primitive murine HSC population, the expression of which decreases upon differentiation to other mature cell types. Sca-1+ HSCs maintain the bone marrow stem cell pool throughout the life. Aplastic anemia is a disease considered to involve primary stem cell deficiency and is characterized by severe pancytopenia and a decline in healthy blood cell generation system. Studies conducted in our laboratory revealed that the primitive Sca-1+ BM-HSCs (bone marrow hematopoietic stem cell) are significantly affected in experimental Aplastic animals pretreated with chemotherapeutic drugs (Busulfan and Cyclophosphamide) and there is increased Caspase-3 activity with consecutive high Annexin-V positivity leading to premature apoptosis in the bone marrow hematopoietic stem cell population in Aplastic condition. The Sca-1bright, that is, “more primitive” BM-HSC population was more affected than the “less primitive” BM-HSC Sca-1dim  population. The decreased cell population and the receptor expression were directly associated with an empty and deranged marrow microenvironment, which is evident from scanning electron microscopy (SEM). The above experimental evidences hint toward the manipulation of receptor expression for the benefit of cytotherapy by primitive stem cell population in Aplastic anemia cases. PMID:21048851

Humic First Theory: A New Theory on the Origin of Life

NASA Astrophysics Data System (ADS)

Daei, Mohammad Ali; Daei, Manijeh; Daei, Bijan

2017-04-01

In 1953, Miller & Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions [1]. During the recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites which have bombarded the ancient earth repeatedly [2]. So simple organic molecules on early earth could be quite enough to start chemical evolution and steadily, proceeded to the very simple form of life. Many theories have tried to explain how life emerged from non life, but failed, largely due to the lack of a distinct methodology. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. It is unacceptable to fill this great distance, only by accidental reactions in a passive media (primitive soap) even, over a very long time. Obviously, manufacturing of a primitive cell required a natural factory with rather firm and resistant basement, plenty of organic and inorganic raw materials and qualified production line, plus some sources of energy. There were plenty of solar energy and water in the early Earth, but what about the other factors? Availability of essential minerals was not guaranteed at all, in primitive earth which covered with bare, dead rocks. While we are not able today, to multiply any microorganisms in ideal conditions of modern laboratory in the absence of only one of essential nutrients or elements, how can we expect primitive cells appear on early earth conditions without the support of soluble minerals and organic matters? Ideal production line must be active and protective, have catalyzing ability, could provide numerous opportunities for interaction between basic bio molecules (mainly RNA and proteins) and above all, have capability to react with different sources of energy. There are strong evidences that show only some form of stable, rich and active organic matter like modern "humic substances" could perform this great and complicated duty. A mass of warm, wet clay mixed with enough humic substances (HS) in suitable PH, could provide all above requirements, and promote biochemical evolution step by step toward a functional primitive cell. HS are fluorescent compounds and could transform UV radiation to usable light. In addition these protective materials could provide chemical energy plus balanced minerals and organic molecules. While everything in non living world is reducing energy, HS can collect more and more material and energy like a living organism. Fortunately, there are reliable evidences that HS could be accessible on ancient Earth. In fact Ziechman et al [7], in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generated on early Earth conditions by polymerizing simple organic molecules. Our investigations show elemental selection and also chairal selection for life are proportionately tailored to Humic materials. For example nearly all heavy metals make insoluble compounds with HS, hence omitted from life processes. In contrast all essential elements have appropriate affinity and workability with HS. There is reliable evidence that shows HS prefer left amino acids and right sugars. As you see many signs and symptoms are referring to "humic substances" as the mother of life, at least on this planet.

Assessment of the number, biomass, and cell size of bacteria in different soils using the "cascade" filtration method

NASA Astrophysics Data System (ADS)

Polyanskaya, L. M.; Pinchuk, I. P.; Zvyagintsev, D. G.

2015-03-01

Soddy-podzolic, gray forest, brown forest, primitive Antarctic soils, typical chernozems, and solonchaks were studied. Many ultrafine bacterial cells, along with fine ones, were found in all the soils studied. The gray forest, brown forest, and primitive Antarctic soils were especially distinguished in this respect. Formerly, in the works on soil microbiology, the fact of the cell size reduction was insufficiently taken into account because of the absence of reliable methods. A decrease in the number and biomass of bacteria down the profile in all the soils, except for the solonchak, was shown. In the solonchak, the bacterial number and biomass increases with decreasing salinity of the soil horizons. The bacterial biomass mainly depends on the predominance of cells of definite sizes (0.38 and 0.23 μm). In the B1fungi horizon of the primitive Antarctic soil, a considerable number of large (1.85 μm) bacterial cells was recorded, and this resulted in the maximal microbial biomass in this horizon. The data on the average volume of a cell correlate with those on the number and biomass of bacteria. The largest diameters of cells were registered in the humus and B1fungi horizons of the primitive Antarctic soil.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meijne, E.I.; van der Winden-van Groenewegen, R.J.; Ploemacher, R.E.

The sensitivity for x-irradiation of a series of hematopoietic stem cell populations has been determined. The most primitive cells identified, cells with marrow-repopulating ability (MRA), showed the highest degree of radioresistance. These MRA cells which generate many secondary day-twelve spleen colony-forming units (MRA(CFU-S-12)) or colony-forming units in culture (MRA(CFU-C)) in the marrow of primary recipients had Do values equal to 1.18 and 1.13 Gy, respectively. The more mature CFU-S-12 had intermediate radiosensitivity (Do = 0.94 Gy), whereas the less primitive CFU-S-7 were the most radiosensitive (Do = 0.71 Gy). The in vitro colony-forming precursor cells (CFU-C) showed low radiosensitivity. Thesemore » data clearly show that the most primitive hematopoietic stem cell measured is less sensitive to ionizing radiation than generally has been assumed on the basis of measurements on CFU-S-7 or CFU-S-12.« less

The cryopreservation protocol optimal for progenitor recovery is not optimal for preservation of marrow repopulating ability.

PubMed

Balint, B; Ivanović, Z; Petakov, M; Taseski, J; Jovcić, G; Stojanović, N; Milenković, P

1999-03-01

The efficiency of five different cryopreservation protocols (our original controlled-rate and noncontrolled-rate protocols) was evaluated on the basis of the recovery after thawing of very primitive pluripotent hemopoietic stem cells (MRA(CFU-GM), pluripotent progenitors (CFU-Sd12) and committed granulocyte-monocyte progenitors (CFU-GM) in mouse bone marrow. Although the nucleated cell recovery and viability determined immediately after the thawing and washing of the cells were found to be similar, whether controlled-rate or noncontrolled-rate cryopreservation protocols were used, the recovery of MRA(CFU-GM), CFU-Sd12 and CFU-GM varied depending on the type of protocol and the cryoprotector (DMSO) concentrations used. It was shown that the controlled-rate protocol was more efficient, enabling better MRA(CFU-GM), CFU-Sd12 and CFU-GM recovery from frozen samples. The most efficient was the controlled-rate protocol of cryopreservation designed to compensate for the release of fusion heat, which enabled a better survival of CFU-Sd12 and CFU-GM when combined with a lower (5%) DMSO concentration. On the contrary, a satisfactory survival rate of very primitive stem cells (MRA(CFU-GM)) was achieved only when 10% DMSO was included with a five-step protocol of cryopreservation. These results point to adequately used controlled-rate freezing as essential for a highly efficient cryopreservation of some of the categories of hematopoietic stem and progenitor cells. At the same time, it was obvious that a higher DMSO concentration was necessary for the cryopreservation of very primitive stem cells, but not, however, for more mature progenitor cells (CFU-S, CFU-GM). These results imply the existence of a mechanism that decreases the intracellular concentration of DMSO in primitive MRA cells, which is not the case for less primitive progenitors.

Applications of human umbilical cord blood cells in central nervous system regeneration.

PubMed

Herranz, Antonio S; Gonzalo-Gobernado, Rafael; Reimers, Diana; Asensio, Maria J; Rodríguez-Serrano, Macarena; Bazán, Eulalia

2010-03-01

In recent decades, there has been considerable amount of information about embryonic stem cells (ES). The dilemma facing scientists interested in the development and use of human stem cells in replacement therapies is the source of these cells, i.e. the human embryo. There are many ethical and moral problems related to the use of these cells. Hematopoietic stem cells from umbilical cord blood have been proposed as an alternative source of embryonic stem cells. After exposure to different agents, these cells are able to express antigens of diverse cellular lineages, including the neural type. The In vitro manipulation of human umbilical cord blood (hUCB) cells has shown their stem capacity and plasticity. These cells are easily accessible, In vitro amplifiable, well tolerated by the host, and with more primitive molecular characteristics that give them great flexibility. Overall, these properties open a promising future for the use of hUCB in regenerative therapies for the Central Nervous System (CNS). This review will focus on the available literature concerning umbilical cord blood cells as a therapeutic tool for the treatment of neurodegenerative diseases.

CD34 Antigen and the MPL Receptor Expression Defines a Novel Class of Human Cord Blood-Derived Primitive Hematopoietic Stem Cells.

PubMed

Matsuoka, Yoshikazu; Takahashi, Masaya; Sumide, Keisuke; Kawamura, Hiroshi; Nakatsuka, Ryusuke; Fujioka, Tatsuya; Sonoda, Yoshiaki

2017-06-09

In the murine hematopoietic stem cell (HSC) compartment, thrombopoietin (THPO)/MPL (THPO receptor) signaling plays an important role in the maintenance of adult quiescent HSCs. However, the role of THPO/MPL signaling in the human primitive HSC compartment has not yet been elucidated. We have identified very primitive human cord blood (CB)-derived CD34- severe combined immunodeficiency (SCID)-repopulating cells (SRCs) using the intra-bone marrow injection method. In this study, we investigated the roles of the MPL expression in the human primitive HSC compartment. The SRC activities of the highly purified CB-derived 18Lin-CD34+/-MPL+/- cells were analyzed using NOG mice. In the primary recipient mice, nearly all mice that received CD34+/-MPL+/- cells were repopulated with human CD45+ cells. Nearly all of these mice that received CD34+MPL+/- and CD34-MPL- cells showed a secondary repopulation. Interestingly, the secondary recipient mice that received CD34+/-MPL- cells showed a distinct tertiary repopulation. These results clearly indicate that the CD34+/- SRCs not expressing MPL sustain a long-term (LT) (>1 year) human cell repopulation in NOG mice. Moreover, CD34- SRCs generate CD34+CD38-CD90+ SRCs in vitro and in vivo. These findings provide a new concept that CD34-MPL- SRCs reside at the apex of the human HSC hierarchy.

Efficient and rapid derivation of primitive neural stem cells and generation of brain subtype neurons from human pluripotent stem cells.

PubMed

Yan, Yiping; Shin, Soojung; Jha, Balendu Shekhar; Liu, Qiuyue; Sheng, Jianting; Li, Fuhai; Zhan, Ming; Davis, Janine; Bharti, Kapil; Zeng, Xianmin; Rao, Mahendra; Malik, Nasir; Vemuri, Mohan C

2013-11-01

Human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are unique cell sources for disease modeling, drug discovery screens, and cell therapy applications. The first step in producing neural lineages from hPSCs is the generation of neural stem cells (NSCs). Current methods of NSC derivation involve the time-consuming, labor-intensive steps of an embryoid body generation or coculture with stromal cell lines that result in low-efficiency derivation of NSCs. In this study, we report a highly efficient serum-free pluripotent stem cell neural induction medium that can induce hPSCs into primitive NSCs (pNSCs) in 7 days, obviating the need for time-consuming, laborious embryoid body generation or rosette picking. The pNSCs expressed the neural stem cell markers Pax6, Sox1, Sox2, and Nestin; were negative for Oct4; could be expanded for multiple passages; and could be differentiated into neurons, astrocytes, and oligodendrocytes, in addition to the brain region-specific neuronal subtypes GABAergic, dopaminergic, and motor neurons. Global gene expression of the transcripts of pNSCs was comparable to that of rosette-derived and human fetal-derived NSCs. This work demonstrates an efficient method to generate expandable pNSCs, which can be further differentiated into central nervous system neurons and glia with temporal, spatial, and positional cues of brain regional heterogeneity. This method of pNSC derivation sets the stage for the scalable production of clinically relevant neural cells for cell therapy applications in good manufacturing practice conditions.

Cinemicrographic study of the cell movement in the primitive-streak-stage mouse embryo.

PubMed

Nakatsuji, N; Snow, M H; Wylie, C C

1986-07-01

Migration of the mesoderm cells in the primitive-streak-stage mouse embryo was directly studied by cinemicrography using whole embryo culture and Nomarski differential interference contrast optics. Relative transparency and small size of the early mouse embryos enabled direct observation of the individual cells and their cell processes. Seven-day-old mouse embryos were isolated and cultured in a small chamber in a medium consisting of 50% rat serum and 50% Dulbecco's modified minimum essential medium. The mesoderm cells move away from the primitive streak in both anterior and antimesometrial (distal) directions at a mean velocity of 46 micron h-1. They extend cell processes and constantly change cell shape. They do not translocate extensively as isolated single cells, but usually maintain attachment to other mesoderm cells. They show frequent cell division preceded by rounding up of the cell bodies, and accompanied by vigorous blebbing before and after cytokinesis. This study shows that it is possible to examine the motility of embryonic cells inside the mammalian embryo by direct observation if the embryo is small and transparent enough for the use of the Nomarski optics.

Stem cells from foetal adnexa and fluid in domestic animals: an update on their features and clinical application.

PubMed

Iacono, E; Rossi, B; Merlo, B

2015-06-01

Over the past decade, stem cell research has emerged as an area of major interest for its potential in regenerative medicine applications. This is in constant need of new cell sources to conceive regenerative medicine approaches for diseases that are still without therapy. Scientists drew the attention towards alternative sources such as foetal adnexa and fluid, as these sources possess many advantages: first of all, cells can be extracted from discarded foetal material and it is non-invasive and inexpensive for the patient; secondly, abundant stem cells can be obtained; and finally, these stem cell sources are free from ethical considerations. Cells derived from foetal adnexa and fluid preserve some of the characteristics of the primitive embryonic layers from which they originate. Many studies have demonstrated the differentiation potential in vitro and in vivo towards mesenchymal and non-mesenchymal cell types; in addition, the immune-modulatory properties make these cells a good candidate for allo- and xenotransplantation. Naturally occurring diseases in domestic animals can be more ideal as disease model of human genetic and acquired diseases and could help to define the potential therapeutic use efficiency and safety of stem cells therapies. This review offers an update on the state of the art of characterization of domestic animals' MSCs derived from foetal adnexa and fluid and on the latest findings in pre-clinical or clinical setting of the stem cell populations isolated from these sources. © 2015 Blackwell Verlag GmbH.

Efficient conservative ADER schemes based on WENO reconstruction and space-time predictor in primitive variables

NASA Astrophysics Data System (ADS)

Zanotti, Olindo; Dumbser, Michael

2016-01-01

We present a new version of conservative ADER-WENO finite volume schemes, in which both the high order spatial reconstruction as well as the time evolution of the reconstruction polynomials in the local space-time predictor stage are performed in primitive variables, rather than in conserved ones. To obtain a conservative method, the underlying finite volume scheme is still written in terms of the cell averages of the conserved quantities. Therefore, our new approach performs the spatial WENO reconstruction twice: the first WENO reconstruction is carried out on the known cell averages of the conservative variables. The WENO polynomials are then used at the cell centers to compute point values of the conserved variables, which are subsequently converted into point values of the primitive variables. This is the only place where the conversion from conservative to primitive variables is needed in the new scheme. Then, a second WENO reconstruction is performed on the point values of the primitive variables to obtain piecewise high order reconstruction polynomials of the primitive variables. The reconstruction polynomials are subsequently evolved in time with a novel space-time finite element predictor that is directly applied to the governing PDE written in primitive form. The resulting space-time polynomials of the primitive variables can then be directly used as input for the numerical fluxes at the cell boundaries in the underlying conservative finite volume scheme. Hence, the number of necessary conversions from the conserved to the primitive variables is reduced to just one single conversion at each cell center. We have verified the validity of the new approach over a wide range of hyperbolic systems, including the classical Euler equations of gas dynamics, the special relativistic hydrodynamics (RHD) and ideal magnetohydrodynamics (RMHD) equations, as well as the Baer-Nunziato model for compressible two-phase flows. In all cases we have noticed that the new ADER schemes provide less oscillatory solutions when compared to ADER finite volume schemes based on the reconstruction in conserved variables, especially for the RMHD and the Baer-Nunziato equations. For the RHD and RMHD equations, the overall accuracy is improved and the CPU time is reduced by about 25 %. Because of its increased accuracy and due to the reduced computational cost, we recommend to use this version of ADER as the standard one in the relativistic framework. At the end of the paper, the new approach has also been extended to ADER-DG schemes on space-time adaptive grids (AMR).

Experimental analysis of control mechanisms in somite segmentation in avian embryos. II. Reduction of material in the gastrula stages of the chick.

PubMed

Bellairs, R; Veini, M

1984-02-01

A new theory of control of somite segmentation in chick embryos is proposed. This supposses that tiny clusters of already programmed cells are present throughout the presumptive somite area at stage 4, but that in order to fulfill their destiny they probably depend on the addition of further cells from the primitive streak. Evidence is based on the two groups of experiments: a) Experiments involving transection across the primitive streak at various stages, (which results in a 'tail' which possesses mesodermal derivatives) and across the segmental plate (which results in a 'tail' lacking mesodermal derivatives). b) Experiments in which parts of embryos have been explanted with or without their primitive streak. It is suggested that the initial clusters of pre-programmed cells move further and further posteriorly, developing into somitomeres (the precursors of true somites) only as they receive re-inforcements from the primitive streak or, ultimately, from the tail bud.

CD34 Antigen and the MPL Receptor Expression Defines a Novel Class of Human Cord Blood-Derived Primitive Hematopoietic Stem Cells

PubMed Central

Matsuoka, Yoshikazu; Takahashi, Masaya; Sumide, Keisuke; Kawamura, Hiroshi; Nakatsuka, Ryusuke; Fujioka, Tatsuya; Sonoda, Yoshiaki

2017-01-01

In the murine hematopoietic stem cell (HSC) compartment, thrombopoietin (THPO)/MPL (THPO receptor) signaling plays an important role in the maintenance of adult quiescent HSCs. However, the role of THPO/MPL signaling in the human primitive HSC compartment has not yet been elucidated. We have identified very primitive human cord blood (CB)-derived CD34– severe combined immunodeficiency (SCID)-repopulating cells (SRCs) using the intra-bone marrow injection method. In this study, we investigated the roles of the MPL expression in the human primitive HSC compartment. The SRC activities of the highly purified CB-derived 18Lin–CD34+/–MPL+/– cells were analyzed using NOG mice. In the primary recipient mice, nearly all mice that received CD34+/–MPL+/– cells were repopulated with human CD45+ cells. Nearly all of these mice that received CD34+MPL+/– and CD34–MPL– cells showed a secondary repopulation. Interestingly, the secondary recipient mice that received CD34+/–MPL– cells showed a distinct tertiary repopulation. These results clearly indicate that the CD34+/– SRCs not expressing MPL sustain a long-term (LT) (>1 year) human cell repopulation in NOG mice. Moreover, CD34– SRCs generate CD34+CD38–CD90+ SRCs in vitro and in vivo. These findings provide a new concept that CD34–MPL– SRCs reside at the apex of the human HSC hierarchy. PMID:27938494

Two different pathways for the transport of primitive and definitive blood cells from the yolk sac to the embryo in humans.

PubMed

Pereda, Jaime; Monge, Juan I; Niimi, Gen

2010-08-01

During the early human embryonic period nutrients and blood cells are temporarily provided by the extraembryonic yolk sac (YS). The YS before week six is involved not only in primitive but also in definitive erythropoiesis. While the destiny of primitive erythroid cells that fill the blood vessels of the YS is well known, the final destination of erythrocytes present in the endodermal vesicular system is unknown. In the present study we have investigated, step by step, the destiny of the erythrocytes present in the endodermal vesicles during the embryonic period. Twelve human YSs and their corresponding yolk stalks were analyzed between weeks 4 and 7 of embryonic age by light and scanning electron microscopy. It is shown that erythrocytes (according to their size and morphological features) located within the endodermal vesicles of the YS wall are pulled out through endodermal pits into the YS cavity, from where they reach the lumen of the primitive gut of the embryo through the vitelline duct, a temporary pathway communicating both compartments. During the study period no erythrocytes were seen within the embryo's vascular network where only primitive erythroblasts were identified. Our results indicate that the vitelline duct plays an important transient role as a pathway for the transport of nutrients and blood cells between the YS and the embryo before week five of embryonic development that ends just at the time when YS-embryo circulation becomes established. (c) 2010 Wiley-Liss, Inc.

Evidence of Mobilization of Pluripotent Stem Cells into Peripheral Blood of Patients with Myocardial Ischemia

PubMed Central

Abdel-Latif, Ahmed; Zuba-Surma, Ewa K.; Ziada, Khaled M.; Kucia, Magdalena; Cohen, Donald A.; Kaplan, Alan M.; Zant, Gary Van; Selim, Samy; Smyth, Susan S.; Ratajczak, Mariusz Z.

2010-01-01

Objective The ischemic myocardium releases multiple chemotactic factors responsible for the mobilization and recruitment of bone marrow-derived cells to injured myocardium. However, the mobilization of primitive pluripotent stem cells (PSCs) enriched in Very Small Embryonic-Like stem cells (VSELs) in various cardiac ischemic scenarios is not well understood. Methods Fifty four ischemic heart disease patients, including subjects with stable angina, non-ST elevation (NSTME) myocardial infarction (MI) and ST elevation myocardial infarction (STEMI), and twelve matched controls were enrolled. The absolute numbers of circulating stem/primitive cells in samples of peripheral blood (PB) were quantitated by Image Stream Analysis and conventional flow cytometry. Gene expression of PSC (Oct-4 and Nanog), early cardiomyocyte (Nkx-2.5 and GATA-4), and endothelial (vWF) markers was analyzed by real-time PCR. Results The absolute numbers of PSCs, stem cell populations enriched in VSELs and hematopoietic stem cells (HSCs) present in PB were significantly higher in STEMI patients at presentation and declined over time. There was a corresponding increase in pluripotent, cardiac and endothelial gene expression in unfractionated PB cells and sorted PB-derived primitive CD34+ cells. The absolute numbers of circulating VSELs and HSCs in STEMI correlated negatively with patients' age. Conclusions Myocardial ischemia mobilizes primitive PSCs including pluripotent VSELs into the circulation. The peak of mobilization occurs within 12 hours in patients presenting with STEMI, which may represent a therapeutic window for future clinical applications. Reduced stem cell mobilization with advancing age could explain, in part, the observation that age is associated with poor prognosis in patients with MI. PMID:20800644

Origin of fatty acid synthesis - Thermodynamics and kinetics of reaction pathways

NASA Technical Reports Server (NTRS)

Weber, Arthur L.

1991-01-01

The primitiveness of contemporary fatty acid biosynthesis was evaluated by using the thermodynamics and kinetics of its component reactions to estimate the extent of its dependence on powerful and selective catalysis by enzymes. Since this analysis indicated that the modern pathway is not primitive because it requires sophisticated enzymatic catalysis, an alternative pathway of primitive fatty acid synthesis is proposed that uses glycolaldehyde as a substrate. In contrast to the modern pathway, this primitive pathway is not dependent on an exogenous source of phosphoanhydride energy. Furthermore, the chemical spontaneity of its reactions suggests that it could have been readily catalyzed by the rudimentary biocatalysts available at an early stage in the origin of life.

Anti-Cancer Phytometabolites Targeting Cancer Stem Cells

PubMed Central

Torquato, Heron F.V.; Goettert, Márcia I.; Justo, Giselle Z.; Paredes-Gamero, Edgar J.

2017-01-01

Medicinal plants are a plentiful source of bioactive molecules with much structural diversity. In cancer treatment, molecules obtained from plants represent an attractive alternative to other treatments because several plant-derived compounds have exhibited lower toxicity and higher selectivity against cancer cells. In this review, we focus on the possible application of bioactive molecules obtained from plants against more primitive cell populations in cancers, cancer stem cells. Cancer stem cells are present in several kinds of tumors and are responsible for recurrences and metastases. Common anti-cancer drugs exhibit lower effectiveness against cancer stem cells because of their biological features. However, recently discovered natural phytometabolites exert cytotoxic effects on this rare population of cells in cancers. Therefore, this review presents the latest research on promising compounds from plants that can act as antitumor drugs and that mainly affect stem cell populations in cancers. PMID:28367074

Comparative Analysis of Human Mesenchymal Stem Cells from Bone Marrow, Adipose Tissue, and Umbilical Cord Blood as Sources of Cell Therapy

PubMed Central

Jin, Hye Jin; Bae, Yun Kyung; Kim, Miyeon; Kwon, Soon-Jae; Jeon, Hong Bae; Choi, Soo Jin; Kim, Seong Who; Yang, Yoon Sun; Oh, Wonil; Chang, Jong Wook

2013-01-01

Various source-derived mesenchymal stem cells (MSCs) have been considered for cell therapeutics in incurable diseases. To characterize MSCs from different sources, we compared human bone marrow (BM), adipose tissue (AT), and umbilical cord blood-derived MSCs (UCB-MSCs) for surface antigen expression, differentiation ability, proliferation capacity, clonality, tolerance for aging, and paracrine activity. Although MSCs from different tissues have similar levels of surface antigen expression, immunosuppressive activity, and differentiation ability, UCB-MSCs had the highest rate of cell proliferation and clonality, and significantly lower expression of p53, p21, and p16, well known markers of senescence. Since paracrine action is the main action of MSCs, we examined the anti-inflammatory activity of each MSC under lipopolysaccharide (LPS)-induced inflammation. Co-culture of UCB-MSCs with LPS-treated rat alveolar macrophage, reduced expression of inflammatory cytokines including interleukin-1α (IL-1α), IL-6, and IL-8 via angiopoietin-1 (Ang-1). Using recombinant Ang-1 as potential soluble paracrine factor or its small interference RNA (siRNA), we found that Ang-1 secretion was responsible for this beneficial effect in part by preventing inflammation. Our results demonstrate that primitive UCB-MSCs have biological advantages in comparison to adult sources, making UCB-MSCs a useful model for clinical applications of cell therapy. PMID:24005862

Why are hematopoietic stem cells so 'sexy'? on a search for developmental explanation.

PubMed

Ratajczak, M Z

2017-08-01

Evidence has accumulated that normal human and murine hematopoietic stem cells express several functional pituitary and gonadal sex hormones, and that, in fact, some sex hormones, such as androgens, have been employed for many years to stimulate hematopoiesis in patients with bone marrow aplasia. Interestingly, sex hormone receptors are also expressed by leukemic cell lines and blasts. In this review, I will discuss the emerging question of why hematopoietic cells express these receptors. A tempting hypothetical explanation for this phenomenon is that hematopoietic stem cells are related to subpopulation of migrating primordial germ cells. To support of this notion, the anatomical sites of origin of primitive and definitive hematopoiesis during embryonic development are tightly connected with the migratory route of primordial germ cells: from the proximal epiblast to the extraembryonic endoderm at the bottom of the yolk sac and then back to the embryo proper via the primitive streak to the aorta-gonado-mesonephros (AGM) region on the way to the genital ridges. The migration of these cells overlaps with the emergence of primitive hematopoiesis in the blood islands at the bottom of the yolk sac, and definitive hematopoiesis that occurs in hemogenic endothelium in the embryonic dorsal aorta in AGM region.

Evaluating Interaction of Cord Blood Hematopoietic Stem/Progenitor Cells with Functionally Integrated Three-Dimensional Microenvironments.

PubMed

Mokhtari, Saloomeh; Baptista, Pedro M; Vyas, Dipen A; Freeman, Charles Jordan; Moran, Emma; Brovold, Matthew; Llamazares, Guillermo A; Lamar, Zanneta; Porada, Christopher D; Soker, Shay; Almeida-Porada, Graça

2018-03-01

Despite advances in ex vivo expansion of cord blood-derived hematopoietic stem/progenitor cells (CB-HSPC), challenges still remain regarding the ability to obtain, from a single unit, sufficient numbers of cells to treat an adolescent or adult patient. We and others have shown that CB-HSPC can be expanded ex vivo in two-dimensional (2D) cultures, but the absolute percentage of the more primitive stem cells decreases with time. During development, the fetal liver is the main site of HSPC expansion. Therefore, here we investigated, in vitro, the outcome of interactions of primitive HSPC with surrogate fetal liver environments. We compared bioengineered liver constructs made from a natural three-dimensional-liver-extracellular-matrix (3D-ECM) seeded with hepatoblasts, fetal liver-derived (LvSt), or bone marrow-derived stromal cells, to their respective 2D culture counterparts. We showed that the inclusion of cellular components within the 3D-ECM scaffolds was necessary for maintenance of HSPC viability in culture, and that irrespective of the microenvironment used, the 3D-ECM structures led to the maintenance of a more primitive subpopulation of HSPC, as determined by flow cytometry and colony forming assays. In addition, we showed that the timing and extent of expansion depends upon the biological component used, with LvSt providing the optimal balance between preservation of primitive CB HSPC and cellular differentiation. Stem Cells Translational Medicine 2018;7:271-282. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Origin and evolution of primitive melts from the Debunscha Maar, Cameroon: Consequences for mantle source heterogeneity within the Cameroon Volcanic Line

NASA Astrophysics Data System (ADS)

Ngwa, Caroline N.; Hansteen, Thor H.; Devey, Colin W.; van der Zwan, Froukje M.; Suh, Cheo E.

2017-09-01

Debunscha Maar is a monogenetic volcano forming part of the Mt. Cameroon volcanic field, located within the Cameroon Volcanic Line (CVL). Partly glassy cauliflower bombs have primitive basanite-picrobasalt compositions and contain abundant normally and reversely zoned olivine (Fo 77-87) and clinopyroxene phenocrysts. Naturally quenched melt inclusions in the most primitive olivine phenocrysts show compositions which, when corrected for post-entrapment modification, cover a wide range from basanite to alkali basalt (MgO 6.9-11.7 wt%), and are generally more primitive than the matrix glasses (MgO 5.0-5.5 wt%) and only partly fall on a common liquid line of descent with the bulk rock samples and matrix glasses. Melt inclusion trace element compositions lie on two distinct geochemical trends: one (towards high Ba/Nb) is thought to represent the effect of various proportions of anhydrous lherzolite and amphibole-bearing peridotite in the source, while the other (for example, high La/Y) reflects variable degrees of partial melting. Comparatively low fractionation-corrected CaO in the melt inclusions with the highest La/Y suggests minor involvement of a pyroxenite source component that is only visible at low degrees of melting. Most of the samples show elevated Gd/Yb, indicating up to 8% garnet in the source. The range of major and trace elements represented by the melt inclusions covers the complete geochemical range given by basalts from different volcanoes of the Cameroon volcanic line, indicating that geochemical signatures that were previously thought to be volcano-specific in fact are probably present under all volcanoes. Clinopyroxene-melt barometry strongly indicates repeated mixing of compositionally diverse melts within the upper mantle at 830 ± 170 MPa prior to eruption. Mantle potential temperatures estimated for the primitive melt inclusions suggest that the thermal influence of a mantle plume is not required to explain the magma petrogenesis.

Origin of primitive ocean island basalts by crustal gabbro assimilation and multiple recharge of plume-derived melts

NASA Astrophysics Data System (ADS)

Borisova, Anastassia Y.; Bohrson, Wendy A.; Grégoire, Michel

2017-07-01

Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine-hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open-system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy-constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21-19 Ma basaltic series, the most primitive series ever found among the Kerguelen OIBs, we performed sixty-seven simulations in the pressure range from 0.2 to 1.0 GPa using compositions of olivine-hosted melt inclusions as parental magmas, and metagabbro xenoliths from the Kerguelen Archipelago as wallrock. MCS modeling requires that the assimilant is anatectic crustal melts (P2O5 ≤ 0.4 wt.% contents) derived from the Kerguelen oceanic metagabbro wallrock. To best fit the phenocryst assemblage observed in the investigated basaltic series, recharge of relatively large masses of hydrous primitive basaltic melts (H2O = 2-3 wt%; MgO = 7-10 wt.%) into a middle crustal chamber at 0.2 to 0.3 GPa is required. Our results thus highlight the important impact that crustal gabbro assimilation and mantle recharge can have on the geochemistry of mantle-derived olivine-phyric OIBs. The importance of crustal assimilation affecting primitive plume-derived basaltic melts underscores that isotopic and chemical equilibrium between ocean island basalts and associated deep plume mantle source(s) may be the exception rather than the rule.

Hard Spheres on the Primitive Surface

NASA Astrophysics Data System (ADS)

Dotera, Tomonari; Takahashi, Yusuke

2015-03-01

Recently hierarchical structures associated with the gyroid in several soft-matter systems have been reported. One of fundamental questions is regular arrangement or tiling on minimal surfaces. We have found certain numbers of hard spheres per unit cell on the gyroid surface are entropically self-organized. Here, new results for the primitive surface are presented. 56/64/72 per unit cell on the primitive minimal surface are entropically self-organized. Numerical evidences for the fluid-solid transition as a function of hard sphere radius are obtained in terms of the acceptance ratio of Monte Carlo moves and order parameters. These arrangements, which are the extensions of the hexagonal arrangement on a flat surface, can be viewed as hyperbolic tiling on the Poincaré disk with a negative Gaussian curvature.

Isolation and characterisation of cancer stem cells from canine osteosarcoma.

PubMed

Wilson, H; Huelsmeyer, M; Chun, R; Young, K M; Friedrichs, K; Argyle, D J

2008-01-01

There is increasing evidence that cancer is a stem cell disease. This study sought to isolate and characterise cancer stem cells from canine osteosarcoma. One human and three canine cell lines were cultured in non-adherent culture conditions using serum-starved, semi-solid media. Primitive sarcosphere colonies from all cell lines were identified under these conditions and were characterised using molecular and cytochemical techniques for embryonic stem cell markers. Expression of the embryonic stem cell-associated genes Nanog, Oct4 and STAT3 indicated a primitive phenotype. Sarcospheres could be reproduced consistently when passaged multiple times and produced adherent cell cultures when returned to normal growth conditions. Similarities between human and canine osteosarcoma cell lines add credence to the potential of the dog as a model for human disease.

Stem cell and peripheral nerve injury and repair.

PubMed

Dong, Ming-min; Yi, Tian-hua

2010-10-01

Peripheral motor nerve injuries are a significant source of morbidity. Neural stem cells (NSCs), a group of relatively primitive cells, possess self-renewal ability and multidifferentiation potential. NSCs may be successfully separated from the human embryo and central nervous system (CNS) and differentiated into mature neurons and gliacytes by in vitro induction or transplantation into the body and may be differentiated into Schwann-like cells under specific conditions. It has been demonstrated that the ability of peripheral nerves to regenerate is mainly attributable to Schwann cells. NSC transplantation can promote peripheral nerve regeneration and provide a new means for treatment of peripheral nerve injury. In recent years, the study of NSCs has become a focus of many laboratories, but the biological characteristics and differentiation regulation mechanisms are not fully clear. In this article, we provide a brief review of NSC characteristics, cultivation, oriented differentiation, and clinical application. © Thieme Medical Publishers.

Targeting Aberrant Glutathione Metabolism to Eradicate Human Acute Myelogenous Leukemia Cells*

PubMed Central

Pei, Shanshan; Minhajuddin, Mohammad; Callahan, Kevin P.; Balys, Marlene; Ashton, John M.; Neering, Sarah J.; Lagadinou, Eleni D.; Corbett, Cheryl; Ye, Haobin; Liesveld, Jane L.; O'Dwyer, Kristen M.; Li, Zheng; Shi, Lei; Greninger, Patricia; Settleman, Jeffrey; Benes, Cyril; Hagen, Fred K.; Munger, Joshua; Crooks, Peter A.; Becker, Michael W.; Jordan, Craig T.

2013-01-01

The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells. PMID:24089526

A gene trap transposon eliminates haematopoietic expression of zebrafish Gfi1aa, but does not interfere with haematopoiesis.

PubMed

Thambyrajah, Roshana; Ucanok, Deniz; Jalali, Maryam; Hough, Yasmin; Wilkinson, Robert Neil; McMahon, Kathryn; Moore, Chris; Gering, Martin

2016-09-01

A transposon-mediated gene trap screen identified the zebrafish line qmc551 that expresses a GFP reporter in primitive erythrocytes and also in haemogenic endothelial cells, which give rise to haematopoietic stem and progenitor cells (HSPCs) that seed sites of larval and adult haematopoiesis. The transposon that mediates this GFP expression is located in intron 1 of the gfi1aa gene, one of three zebrafish paralogs that encode transcriptional repressors homologous to mammalian Gfi1 and Gfi1b proteins. In qmc551 transgenics, GFP expression is under the control of the endogenous gfi1aa promoter, recapitulates early gfi1aa expression and allows live observation of gfi1aa promoter activity. While the transposon integration interferes with the expression of gfi1aa mRNA in haematopoietic cells, homozygous qmc551 fish are viable and fertile, and display normal primitive and definitive haematopoiesis. Retained expression of Gfi1b in primitive erythrocytes and up-regulation of Gfi1ab at the onset of definitive haematopoiesis in homozygous qmc551 carriers, are sufficient to allow normal haematopoiesis. This finding contradicts previously published morpholino data that suggested an essential role for zebrafish Gfi1aa in primitive erythropoiesis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Comparison of direct and indirect radiation effects on osteoclast formation from progenitor cells derived from different hemopoietic sources.

PubMed

Scheven, B A; Wassenaar, A M; Kawilarang-de Haas, E W; Nijweide, P J

1987-07-01

Hemopoietic stem and progenitor cells from different sources differ in radiosensitivity. Recently, we have demonstrated that the multinucleated cell responsible for bone resorption and marrow cavity formation, the osteoclast, is in fact of hemopoietic lineage. In this investigation we have studied the radiosensitivity of osteoclast formation from two different hemopoietic tissues: fetal liver and adult bone marrow. Development of osteoclasts from hemopoietic progenitors was induced by coculture of hemopoietic cell populations with fetal mouse long bones depleted of their own osteoclast precursor pool. During culture, osteoclasts developed from the exogenous cell population and invaded the calcified hypertrophic cartilage of the long bone model, thereby giving rise to the formation of a primitive marrow cavity. To analyze the radiosensitivity of osteoclast formation, either the hemopoietic cells or the bone rudiments were irradiated before coculture. Fetal liver cells were found to be less radiosensitive than bone marrow cells. The D0, Dq values and extrapolation numbers were 1.69 Gy, 5.30 Gy, and 24.40 for fetal liver cells and 1.01 Gy, 1.85 Gy, and 6.02 for bone marrow cells. Irradiation of the (pre)osteoclast-free long bone rudiments instead of the hemopoietic sources resulted in a significant inhibition of osteoclast formation at doses of 4 Gy or more. This indirect effect appeared to be more prominent in the cocultures with fetal than with adult hemopoietic cells. Furthermore, radiation doses of 8.0-10.0 Gy indirectly affected the appearance of other cell types (e.g., granulocytes) in the newly formed but underdeveloped marrow cavity. The results indicate that osteoclast progenitors from different hemopoietic sources exhibit a distinct sensitivity to ionizing irradiation. Radiation injury to long bone rudiments disturbs the osteoclast-forming capacity as well as the hemopoietic microenvironment.

The Open Source Hardening Project

DTIC Science & Technology

2009-07-01

invariants have been violated. Further, despite the severity of storage system bugs, deployed testing meth- ods remain primitive , typically a combination of...an exponen- tially increasing number all-at-once. As a result, EX- PLODE unsurprisingly looks like a primitive operating system: it has a queue of...via semaphores . However, doing so requires intrusive changes and, in our experience [30], backfires with unexpected deadlock since semaphores prevent a

AMORE; The Advanced Multimedia Organizer for Requirements Elicitation

DTIC Science & Technology

1993-06-01

terms of cinematic primitives, including: perspective, camera, sound, content, and context [Davenport 91]. Ambient sound can be used to provide...concept) [Dumais 88], [Salton 83]. Latent semantic indexing [Dumais 88] could improve the access to video shots described by cinematic primitives. As...into classes (includ- the cited articles) video source ing cinematic primi- tives) CMU/SEI-93-TR-12 33 A.6 Tree-Maps Retrieval Visualization

CD71(high) population represents primitive erythroblasts derived from mouse embryonic stem cells.

PubMed

Chao, Ruihua; Gong, Xueping; Wang, Libo; Wang, Pengxiang; Wang, Yuan

2015-01-01

The CD71/Ter119 combination has been widely used to reflect dynamic maturation of erythrocytes in vivo. However, because CD71 is expressed on all proliferating cells, it is unclear whether it can be utilized as an erythrocyte-specific marker during differentiation of embryonic stem cells (ESCs). In this study, we revealed that a population expressing high level of CD71 (CD71(high)) during mouse ESC differentiation represented an in vitro counterpart of yolk sac-derived primitive erythroblasts (EryPs) isolated at 8.5days post coitum. In addition, these CD71(high) cells went through "maturational globin switching" and enucleated during terminal differentiation in vitro that were similar to the yolk sac-derived EryPs in vivo. We further demonstrated that the formation of CD71(high) population was regulated differentially by key factors including Scl, HoxB4, Eaf1, and Klf1. Taken together, our study provides a technical advance that allows efficient segregation of EryPs from differentiated ESCs in vitro for further understanding molecular regulation during primitive erythropoiesis. Copyright © 2014. Published by Elsevier B.V.

Attributed relational graphs for cell nucleus segmentation in fluorescence microscopy images.

PubMed

Arslan, Salim; Ersahin, Tulin; Cetin-Atalay, Rengul; Gunduz-Demir, Cigdem

2013-06-01

More rapid and accurate high-throughput screening in molecular cellular biology research has become possible with the development of automated microscopy imaging, for which cell nucleus segmentation commonly constitutes the core step. Although several promising methods exist for segmenting the nuclei of monolayer isolated and less-confluent cells, it still remains an open problem to segment the nuclei of more-confluent cells, which tend to grow in overlayers. To address this problem, we propose a new model-based nucleus segmentation algorithm. This algorithm models how a human locates a nucleus by identifying the nucleus boundaries and piecing them together. In this algorithm, we define four types of primitives to represent nucleus boundaries at different orientations and construct an attributed relational graph on the primitives to represent their spatial relations. Then, we reduce the nucleus identification problem to finding predefined structural patterns in the constructed graph and also use the primitives in region growing to delineate the nucleus borders. Working with fluorescence microscopy images, our experiments demonstrate that the proposed algorithm identifies nuclei better than previous nucleus segmentation algorithms.

Tubulin post-translational modifications in the primitive protist Trichomonas vaginalis.

PubMed

Delgado-Viscogliosi, P; Brugerolle, G; Viscogliosi, E

1996-01-01

Using several specific monoclonal antibodies, we investigated the occurrence and distribution of different post-translationally modified tubulin during interphase and division of the primitive flagellated protist Trichomonas vaginalis. Immunoblotting and immunofluorescence experiments revealed that interphasic microtubular structures of T. vaginalis contained acetylated and glutamylated but non-tyrosinated and non-glycylated [Brugerolle and Adoutte, 1988: Bio Systems 21: 255-268] tubulin. Immunofluorescence studies performed on dividing cells showed that the extranuclear mitotic spindle (or paradesmosis) was acetylated and glutamylated, which contrast with the ephemeral nature of this structure. Newly formed short axostyles also contained acetylated and glutamylated tubulin suggesting that both post-translational modifications might take place very early after assembly of microtubular structures. Our results indicate that acetylation and glutamylation of tubulin appeared early in the history of eukaryotes and could reflect the occurrence of post-translational modifications of tubulin in the primitive eukaryotic cells. These cells probably had a highly ordered cross-linked microtubular cytoskeleton in which microtubules showed a low level of subunit exchange dynamics.

Transduction of Human Primitive Repopulating Hematopoietic Cells With Lentiviral Vectors Pseudotyped With Various Envelope Proteins

PubMed Central

Kim, Yoon-Sang; Wielgosz, Matthew M; Hargrove, Phillip; Kepes, Steven; Gray, John; Persons, Derek A; Nienhuis, Arthur W

2010-01-01

Lentiviral vectors are useful for transducing primitive hematopoietic cells. We examined four envelope proteins for their ability to mediate lentiviral transduction of mobilized human CD34+ peripheral blood cells. Lentiviral particles encoding green fluorescent protein (GFP) were pseudotyped with the vesicular stomatitis virus envelope glycoprotein (VSV-G), the amphotropic (AMPHO) murine leukemia virus envelope protein, the endogenous feline leukemia viral envelope protein or the feline leukemia virus type C envelope protein. Because the relative amount of genome RNA per ml was similar for each pseudotype, we transduced CD34+ cells with a fixed volume of each vector preparation. Following an overnight transduction, CD34+ cells were transplanted into immunodeficient mice which were sacrificed 12 weeks later. The average percentages of engrafted human CD45+ cells in total bone marrow were comparable to that of the control, mock-transduced group (37–45%). Lenti-particles pseudotyped with the VSV-G envelope protein transduced engrafting cells two- to tenfold better than particles pseudotyped with any of the γ-retroviral envelope proteins. There was no correlation between receptor mRNA levels for the γ-retroviral vectors and transduction efficiency of primitive hematopoietic cells. These results support the use of the VSV-G envelope protein for the development of lentiviral producer cell lines for manufacture of clinical-grade vector. PMID:20372106

Targeting the aryl hydrocarbon receptor nuclear translocator complex with DMOG and Stemregenin 1 improves primitive hematopoietic stem cell expansion.

PubMed

Jackson, Carlo Stephan; Durandt, Chrisna; Janse van Rensburg, Ilse; Praloran, Vincent; Brunet de la Grange, Philippe; Pepper, Michael Sean

2017-05-01

Culture conditions used for the expansion of hematopoietic stem and progenitor cells (HSCs and HPCs, collectively HSPCs) should ideally favor the self renewal of long-term HSCs. At 20% O 2 , the synthesis of HIF-1α is balanced by its hydroxylation and proteasomal degradation. This favors HSPC differentiation, but can be prevented by culturing CD34+ cord blood cells in the presence of dimethyloxaloylglycine (DMOG). This differentiation may also be reduced by culturing the cells in the presence of Stemregenin 1, an antagonist of the aryl hydrocarbon receptor (AhR). The objective of this study was to investigate how hypoxia, DMOG and Stemregenin 1 might affect the expansion of HSPCs with the aim of identifying optimal conditions for expansion in culture. It was found that DMOG decreased proliferation but was effective in preserving the number of cells in the primitive hematopoietic sub-populations in vitro. The effect of DMOG was similar to hypoxia, although differences were observed with regard to the side population and CD34+ sub-populations. Stemregenin 1 on the other hand increased the size of the primitive as well as the other HSC sub-populations. The use of Stemregenin 1 with DMOG increased the proportion of primitive HSCs to 3.54% compared to 2.61% for Stemregenin 1 alone. In vivo engraftment studies confirmed these findings and showed that fewer cells (3710) are required for long-term engraftment when HSCs are grown in Stemregenin 1 together with hypoxia than in Stemregenin 1 under conditions of normoxia (13430). Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Palbociclib in Treating Patients With Relapsed or Refractory Rb Positive Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With Activating Alterations in Cell Cycle Genes (A Pediatric MATCH Treatment Trial)

ClinicalTrials.gov

2018-06-13

Advanced Malignant Solid Neoplasm; RB1 Positive; Recurrent Childhood Ependymoma; Recurrent Ewing Sarcoma; Recurrent Glioma; Recurrent Hepatoblastoma; Recurrent Kidney Wilms Tumor; Recurrent Langerhans Cell Histiocytosis; Recurrent Malignant Germ Cell Tumor; Recurrent Malignant Glioma; Recurrent Medulloblastoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Peripheral Primitive Neuroectodermal Tumor; Recurrent Rhabdoid Tumor; Recurrent Rhabdomyosarcoma; Recurrent Soft Tissue Sarcoma; Refractory Ependymoma; Refractory Ewing Sarcoma; Refractory Glioma; Refractory Hepatoblastoma; Refractory Langerhans Cell Histiocytosis; Refractory Malignant Germ Cell Tumor; Refractory Malignant Glioma; Refractory Medulloblastoma; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Refractory Osteosarcoma; Refractory Peripheral Primitive Neuroectodermal Tumor; Refractory Rhabdoid Tumor; Refractory Rhabdomyosarcoma; Refractory Soft Tissue Sarcoma

Fanconi anemia genes are highly expressed in primitive CD34+ hematopoietic cells

PubMed Central

Aubé, Michel; Lafrance, Matthieu; Brodeur, Isabelle; Delisle, Marie-Chantal; Carreau, Madeleine

2003-01-01

Background Fanconi anemia (FA) is a complex recessive genetic disease characterized by progressive bone marrow failure (BM) and a predisposition to cancer. We have previously shown using the Fancc mouse model that the progressive BM failure results from a hematopoietic stem cell defect suggesting that function of the FA genes may reside in primitive hematopoietic stem cells. Methods Since genes involved in stem cell differentiation and/or maintenance are usually regulated at the transcription level, we used a semiquantitative RT-PCR method to evaluate FA gene transcript levels in purified hematopoietic stem cells. Results We show that most FA genes are highly expressed in primitive CD34-positive and negative cells compared to lower levels in more differentiated cells. However, in CD34- stem cells the Fancc gene was found to be expressed at low levels while Fancg was undetectable in this population. Furthermore, Fancg expression is significantly decreased in Fancc -/- stem cells as compared to wild-type cells while the cancer susceptibility genes Brca1 and Fancd1/Brac2 are upregulated in Fancc-/- hematopoietic cells. Conclusions These results suggest that FA genes are regulated at the mRNA level, that increased Fancc expression in LTS-CD34+ cells correlates with a role at the CD34+ differentiation stage and that lack of Fancc affects the expression of other FA gene, more specifically Fancg and Fancd1/Brca2, through an unknown mechanism. PMID:12809565

Individual blastomeres of 16- and 32-cell mouse embryos are able to develop into foetuses and mice.

PubMed

Tarkowski, Andrzej K; Suwińska, Aneta; Czołowska, Renata; Ożdżeński, Wacław

2010-12-15

Cell and developmental studies have clarified how, by the time of implantation, the mouse embryo forms three primary cell lineages: epiblast (EPI), primitive endoderm (PE), and trophectoderm (TE). However, it still remains unknown when cells allocated to these three lineages become determined in their developmental fate. To address this question, we studied the developmental potential of single blastomeres derived from 16- and 32-cell stage embryos and supported by carrier, tetraploid blastomeres. We were able to generate singletons, identical twins, triplets, and quadruplets from individual inner and outer cells of 16-cell embryos and, sporadically, foetuses from single cells of 32-cell embryos. The use of embryos constitutively expressing GFP as the donors of single diploid blastomeres enabled us to identify their cell progeny in the constructed 2n↔4n blastocysts. We showed that the descendants of donor blastomeres were able to locate themselves in all three first cell lineages, i.e., epiblast, primitive endoderm, and trophectoderm. In addition, the application of Cdx2 and Gata4 markers for trophectoderm and primitive endoderm, respectively, showed that the expression of these two genes in the descendants of donor blastomeres was either down- or up-regulated, depending on the cell lineage they happened to occupy. Thus, our results demonstrate that up to the early blastocysts stage, the destiny of at least some blastomeres, although they have begun to express markers of different lineage, is still labile. Copyright © 2010 Elsevier Inc. All rights reserved.

Characterization of selected elementary motion detector cells to image primitives.

PubMed

Benson, Leslie A; Barrett, Steven F; Wright, Cameron H G

2008-01-01

Developing a visual sensing system, complete with motion processing hardware and software would have many applications to current technology. It could be mounted on many autonomous vehicles to provide information about the navigational environment, as well as obstacle avoidance features. Incorporating the motion processing capabilities into the sensor requires a new approach to the algorithm implementation. This research, and that of many others, have turned to nature for inspiration. Elementary motion detector (EMD) cells are involved in a biological preprocessing network to provide information to the motion processing lobes of the house degrees y Musca domestica. This paper describes the response of the photoreceptor inputs to the EMDs. The inputs to the EMD components are tested as they are stimulated with varying image primitives. This is the first of many steps in characterizing the EMD response to image primitives.

Mesenchymal Stem Cells and the Origin of Ewing's Sarcoma

PubMed Central

Lin, Patrick P.; Wang, Yongxing; Lozano, Guillermina

2011-01-01

The origin of Ewing's sarcoma is a subject of much debate. Once thought to be derived from primitive neuroectodermal cells, many now believe it to arise from a mesenchymal stem cell (MSC). Expression of the EWS-FLI1 fusion gene in MSCs changes cell morphology to resemble Ewing's sarcoma and induces expression of neuroectodermal markers. In murine cells, transformation to sarcomas can occur. In knockdown experiments, Ewing's sarcoma cells develop characteristics of MSCs and the ability to differentiate into mesodermal lineages. However, it cannot be concluded that MSCs are the cell of origin. The concept of an MSC still needs to be rigorously defined, and there may be different subpopulations of mesenchymal pluripotential cells. Furthermore, EWS-FLI1 by itself does not transform human cells, and cooperating mutations appear to be necessary. Therefore, while it is possible that Ewing's sarcoma may originate from a primitive mesenchymal cell, the idea needs to be refined further. PMID:20953407

The Origin of Primitive Cells, Nutrient Intake, and Non-Enzymatic Elongation of Encapsulated Nucleotides

NASA Technical Reports Server (NTRS)

Meierhenrich, Uwe J.; Filippi, Jean-Jacques; Meinert, Cornelia; Vierling, Pierre; Dworkin, Jason P.

2009-01-01

Fatty acids and fatty alcohols are commonly found in experiments simulating the prebiotic 'soup'. These amphiphiles can be synthesized under prebiotic conditions, at least as long as the molecules are chemically relatively simple and do not need to be enantiomerically pure. In the context of topical origin-of-life theories, two distinct formation pathways for amphiphiles have been described; one related to geophysical sites, such as marine hydrothermal systems, and another to extraterrestrial sources, such as the proto-solar nebula, which was fed by interplanetary and interstellar nebulae. The chemical analysis of each provides individual characteristic challenges.

The Coherent Interlayer Resistance of a Single, Misoriented Interface between Two Graphite Stacks

NASA Astrophysics Data System (ADS)

Lake, Roger K.; Habib, K. M. Masum; Sylvia, Somaia; Ge, Supeng; Neupane, Mahesh

2014-03-01

The coherent, interlayer resistance of a misoriented, rotated interface between two stacks of AB graphite is determined for a variety of misorientation angles ranging from 0° to 27 .29° . The quantum-resistance of the ideal AB stack is on the order of 1 to 10 m Ωμm2 depending on the Fermi energy. For small rotation angles <= 7 .34° , the coherent interlayer resistance exponentially approaches the ideal quantum resistance at energies away from the charge neutrality point. Over a range of intermediate angles, the resistance increases exponentially with primitive cell size for minimum size cells. A change of misorientation angle by one degree can increase the primitive cell size by three orders of magnitude. These large cell sizes may not follow the exponential trend of the minimal cells especially at energies a few hundred meV away from the charge neutrality point. At such energies, their coherent interlayer resistance is likely to coincide with that of a nearby rotation angle with a much smaller primitive cell. The energy dependence of the interlayer transmission is described and analyzed. This work was supported in part by FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA.

Local bone marrow renin-angiotensin system in primitive, definitive and neoplastic haematopoiesis.

PubMed

Haznedaroglu, Ibrahim C; Beyazit, Yavuz

2013-03-01

The locally active ligand peptides, mediators, receptors and signalling pathways of the haematopoietic BM (bone marrow) autocrine/paracrine RAS (renin-angiotensin system) affect the essential steps of definitive blood cell production. Haematopoiesis, erythropoiesis, myelopoiesis, formation of monocytic and lymphocytic lineages, thrombopoiesis and other stromal cellular elements are regulated by the local BM RAS. The local BM RAS is present and active even in primitive embryonic haematopoiesis. ACE (angiotensin-converting enzyme) is expressed on the surface of the first endothelial and haematopoietic cells, forming the marrow cavity in the embryo. ACE marks early haematopoietic precursor cells and long-term blood-forming CD34(+) BM cells. The local autocrine tissue BM RAS may also be active in neoplastic haematopoiesis. Critical RAS mediators such as renin, ACE, AngII (angiotensin II) and angiotensinogen have been identified in leukaemic blast cells. The local tissue RAS influences tumour growth and metastases in an autocrine and paracrine fashion via the modulation of numerous carcinogenic events, such as angiogenesis, apoptosis, cellular proliferation, immune responses, cell signalling and extracellular matrix formation. The aim of the present review is to outline the known functions of the local BM RAS within the context of primitive, definitive and neoplastic haematopoiesis. Targeting the actions of local RAS molecules could represent a valuable therapeutic option for the management of neoplastic disorders.

Comparison of Gene Expression in Human Embryonic Stem Cells, hESC-Derived Mesenchymal Stem Cells and Human Mesenchymal Stem Cells.

PubMed

Barbet, Romain; Peiffer, Isabelle; Hatzfeld, Antoinette; Charbord, Pierre; Hatzfeld, Jacques A

2011-01-01

We present a strategy to identify developmental/differentiation and plasma membrane marker genes of the most primitive human Mesenchymal Stem Cells (hMSCs). Using sensitive and quantitative TaqMan Low Density Arrays (TLDA) methodology, we compared the expression of 381 genes in human Embryonic Stem Cells (hESCs), hESC-derived MSCs (hES-MSCs), and hMSCs. Analysis of differentiation genes indicated that hES-MSCs express the sarcomeric muscle lineage in addition to the classical mesenchymal lineages, suggesting they are more primitive than hMSCs. Transcript analysis of membrane antigens suggests that IL1R1(low), BMPR1B(low), FLT4(low), LRRC32(low), and CD34 may be good candidates for the detection and isolation of the most primitive hMSCs. The expression in hMSCs of cytokine genes, such as IL6, IL8, or FLT3LG, without expression of the corresponding receptor, suggests a role for these cytokines in the paracrine control of stem cell niches. Our database may be shared with other laboratories in order to explore the considerable clinical potential of hES-MSCs, which appear to represent an intermediate developmental stage between hESCs and hMSCs.

Flavopiridol in Treating Children With Relapsed or Refractory Solid Tumors or Lymphomas

ClinicalTrials.gov

2013-07-01

Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Retinoblastoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Recurrent/Refractory Childhood Hodgkin Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific

Hydrazines and carbohydrazides produced from oxidized carbon in earth's primitive environment

NASA Technical Reports Server (NTRS)

Folsome, C. E.; Brittain, A.; Smith, A.; Chang, S.

1981-01-01

Whether abiological organic compounds can be formed from the interactions of energy sources with nitrogen, oxidized carbon and water is held to be of importance in geochemical models of the primordial earth atmosphere. It is reported that experiments using quenched spark discharges through molecular nitrogen on aqueous suspensions of CaCO3 and other reactants to simulate the hydrosphere/atmosphere interface yield hydrazine and carbohydrazine in significant but low yields. Such reactions in primitive aquatic environments may have supplied a pathway for chemical evolution and the origin of life, on a primitive earth in which fully oxidized states of carbon were available for the primary synthesis of organic matter.

The role of water in the petrogenesis of Marina trough magmas

NASA Astrophysics Data System (ADS)

Stolper, Edward; Newman, Sally

1994-02-01

Most variations in composition among primitive basalts from the Mariana back-arc trough can be explained by melting mixtures of an N-type mid-ocean ridge basalt (NMORB) mantle source and an H2O rich component, provided the degree of melting is positively and approximately linearly correlated with the proportion of the H2O-rich component in the mixture. We conclude that the degrees of melting by which Mariana trough magmas are generated increase from magmas similar to NMORB, through more H2O-enriched basalts, to 'arc-like' basalts, and that this increase is due to the lowering of the solidus of mantle peridotite that accompanies addition of the H2O-rich component. The H2O-rich component is likely to be ultimately derived from fluid from a subducting slab, but we propose that by the time fluids reach the source regions of Mariana trough basalts, they have interacted with sufficient mantle material that for all but the most incompatible of elements (with respect to fluid-mantle interaction), they are in equilibrium with the mantle. In contrast, fluids added to the source regions of Mariana island-arc magmas have typically interacted with less mantle and thus retain the signature of slab-derived fluids to varying degrees for all but the most compatible elements. Primitive Mariana arc basalts can be generated by melting mixtures of such incompletely exchanged slab-derived fluids and sources similar to NMORB-type mantle sources, but the degrees of melting are typically higher than those of Mariana trough NMORB and the sources have been variably depleted relative to the back-arc sources by previous melt extraction. This depletion may be related to earlier extraction of back-arc basin magmas or may evolve by repeated fluxing of the sources as fluid is continually added to them in the regions of arc magma generation. If fluid with partitioning behavior relative to the solid mantle similar to that deduced for the H2O-rich component involved in the generation of Mariana trough basalts were extracted from primitive mantle, the residual mantle would have many of the minor and trace element characteristics of typical oceanic upper mantle; primitive mantle enriched in such fluid would be a satisfactory source for the continental crust in terms of its trace and minor element chemical composition.

Differentiation stage-specific regulation of primitive human hematopoietic progenitor cycling by exogenous and endogenous inhibitors in an in vivo model.

PubMed

Cashman, J D; Clark-Lewis, I; Eaves, A C; Eaves, C J

1999-12-01

Nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice transplanted with human cord blood or adult marrow cells and injected 6 weeks posttransplant with 2 daily doses of transforming growth factor-beta(1) (TGF-beta(1)), monocyte chemoattractant protein-1 (MCP-1), or a nonaggregating form of macrophage inflammatory protein-1alpha (MIP-1alpha) showed unique patterns of inhibition of human progenitor proliferation 1 day later. TGF-beta(1) was active on long-term culture initiating cells (LTC-IC) and on primitive erythroid and granulopoietic colony-forming cells (HPP-CFC), but had no effect on mature CFC. MCP-1 inhibited the cycling of both types of HPP-CFC but not LTC-IC. MIP-1alpha did not inhibit either LTC-IC or granulopoietic HPP-CFC but was active on erythroid HPP-CFC and mature granulopoietic CFC. All of these responses were independent of the source of human cells transplanted. LTC-IC of either human cord blood or adult marrow origin continue to proliferate in NOD/SCID mice for many weeks, although the turnover of all types of human CFC in mice transplanted with adult human marrow (but not cord blood) is downregulated after 6 weeks. Interestingly, administration of either MIP-1beta, an antagonist of both MIP-1alpha and MCP-1 or MCP-1(9-76), an antagonist of MCP-1 (and MCP-2 and MCP-3), into mice in which human marrow-derived CFC had become quiescent, caused the rapid reactivation of these progenitors in vivo. These results provide the first definition of stage-specific inhibitors of human hematopoietic progenitor cell cycling in vivo. In addition they show that endogenous chemokines can contribute to late graft failure, which can be reversed by the administration of specific antagonists.

Krüppel-Like Factor 1 (KLF1), KLF2, and Myc Control a Regulatory Network Essential for Embryonic Erythropoiesis

PubMed Central

Pang, Christopher J.; Lemsaddek, Wafaa; Alhashem, Yousef N.; Bondzi, Cornelius; Redmond, Latasha C.; Ah-Son, Nicolas; Dumur, Catherine I.; Archer, Kellie J.; Haar, Jack L.

2012-01-01

The Krüppel-like factor 1 (KLF1) and KLF2 positively regulate embryonic β-globin expression and have additional overlapping roles in embryonic (primitive) erythropoiesis. KLF1−/− KLF2−/− double knockout mice are anemic at embryonic day 10.5 (E10.5) and die by E11.5, in contrast to single knockouts. To investigate the combined roles of KLF1 and KLF2 in primitive erythropoiesis, expression profiling of E9.5 erythroid cells was performed. A limited number of genes had a significantly decreasing trend of expression in wild-type, KLF1−/−, and KLF1−/− KLF2−/− mice. Among these, the gene for Myc (c-Myc) emerged as a central node in the most significant gene network. The expression of the Myc gene is synergistically regulated by KLF1 and KLF2, and both factors bind the Myc promoters. To characterize the role of Myc in primitive erythropoiesis, ablation was performed specifically in mouse embryonic proerythroblast cells. After E9.5, these embryos exhibit an arrest in the normal expansion of circulating red cells and develop anemia, analogous to KLF1−/− KLF2−/− embryos. In the absence of Myc, circulating erythroid cells do not show the normal increase in α- and β-like globin gene expression but, interestingly, have accelerated erythroid cell maturation between E9.5 and E11.5. This study reveals a novel regulatory network by which KLF1 and KLF2 regulate Myc to control the primitive erythropoietic program. PMID:22566683

Oxaliplatin and Irinotecan in Treating Young Patients With Refractory Solid Tumors or Lymphomas

ClinicalTrials.gov

2013-06-04

Childhood Burkitt Lymphoma; Childhood Central Nervous System Germ Cell Tumor; Childhood Diffuse Large Cell Lymphoma; Childhood Grade III Lymphomatoid Granulomatosis; Childhood Immunoblastic Large Cell Lymphoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway Glioma; Recurrent Colon Cancer; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Melanoma; Recurrent Nasopharyngeal Cancer; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Wilms Tumor and Other Childhood Kidney Tumors; Recurrent/Refractory Childhood Hodgkin Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific

Is alkaline phosphatase the smoking gun for highly refractory primitive leukemic cells?

PubMed Central

Rico, Laura G.; Juncà, Jordi; Ward, Mike D.; Bradford, Jolene; Petriz, Jordi

2016-01-01

With the aim to detect candidate malignant primitive progenitor populations, we modified an original alkaline phosphatase (ALP) stem cell detection method based on the identification of alkaline phosphatase fluorescent cells in combination with flow cytometry immunophenotyping. Over a period of one year, we have been using this technique to study its activity in patients with leukemia and lymphoma, showing that changes in the alkaline phosphatase levels can be used to detect rare populations of highly refractory malignant cells. By screening different blood cancers, we have observed that this activity is not always restricted to CD34+ leukemic cells, and can be overexpressed in CD34 negative leukemia. We have verified that this method gives accurate and reproducible measurements and our preliminary results suggest that CD34+/ALPhigh cells appear to sustain leukemogenesis over time. PMID:27732563

Development of an interpretive simulation tool for the proton radiography technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levy, M. C., E-mail: levymc@stanford.edu; Lawrence Livermore National Laboratory, Livermore, California 94551; Ryutov, D. D.

2015-03-15

Proton radiography is a useful diagnostic of high energy density (HED) plasmas under active theoretical and experimental development. In this paper, we describe a new simulation tool that interacts realistic laser-driven point-like proton sources with three dimensional electromagnetic fields of arbitrary strength and structure and synthesizes the associated high resolution proton radiograph. The present tool’s numerical approach captures all relevant physics effects, including effects related to the formation of caustics. Electromagnetic fields can be imported from particle-in-cell or hydrodynamic codes in a streamlined fashion, and a library of electromagnetic field “primitives” is also provided. This latter capability allows users tomore » add a primitive, modify the field strength, rotate a primitive, and so on, while quickly generating a high resolution radiograph at each step. In this way, our tool enables the user to deconstruct features in a radiograph and interpret them in connection to specific underlying electromagnetic field elements. We show an example application of the tool in connection to experimental observations of the Weibel instability in counterstreaming plasmas, using ∼10{sup 8} particles generated from a realistic laser-driven point-like proton source, imaging fields which cover volumes of ∼10 mm{sup 3}. Insights derived from this application show that the tool can support understanding of HED plasmas.« less

Pancreatic Endoderm-Derived From Diabetic Patient-Specific Induced Pluripotent Stem Cell Generates Glucose-Responsive Insulin-Secreting Cells.

PubMed

Rajaei, Bahareh; Shamsara, Mehdi; Amirabad, Leila Mohammadi; Massumi, Mohammad; Sanati, Mohammad Hossein

2017-10-01

Human-induced pluripotent stem cells (hiPSCs) can potentially serve as an invaluable source for cell replacement therapy and allow the creation of patient- and disease-specific stem cells without the controversial use of embryos and avoids any immunological incompatibility. The generation of insulin-producing pancreatic β-cells from pluripotent stem cells in vitro provides an unprecedented cell source for personal drug discovery and cell transplantation therapy in diabetes. A new five-step protocol was introduced in this study, effectively induced hiPSCs to differentiate into glucose-responsive insulin-producing cells. This process mimics in vivo pancreatic organogenesis by directing cells through stages resembling definitive endoderm, primitive gut-tube endoderm, posterior foregut, pancreatic endoderm, and endocrine precursor. Each stage of differentiation were characterized by stage-specific markers. The produced cells exhibited many properties of functional β-cells, including expression of critical β-cells transcription factors, the potency to secrete C-peptide in response to high levels of glucose and the presence of mature endocrine secretory granules. This high efficient differentiation protocol, established in this study, yielded 79.18% insulin-secreting cells which were responsive to glucose five times higher than the basal level. These hiPSCs-derived glucose-responsive insulin-secreting cells might provide a promising approach for the treatment of type I diabetes mellitus. J. Cell. Physiol. 232: 2616-2625, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Primitive macrophages control HSPC mobilization and definitive haematopoiesis.

PubMed

Travnickova, Jana; Tran Chau, Vanessa; Julien, Emmanuelle; Mateos-Langerak, Julio; Gonzalez, Catherine; Lelièvre, Etienne; Lutfalla, Georges; Tavian, Manuela; Kissa, Karima

2015-02-17

In vertebrates, haematopoietic stem/progenitor cells (HSPCs) first emerge in the aorta-gonad-mesonephros (AGM) before colonizing transitory and subsequently definitive haematopoietic organs allowing haematopoiesis throughout adult life. Here we identify an unexpected primitive macrophage population accumulated in the dorsal mesenteric mesoderm surrounding the dorsal aorta of the human embryo and study its function in the transparent zebrafish embryo. Our study reveals dynamic interactions occurring between the HSPCs and primitive macrophages in the AGM. Specific chemical and inducible genetic depletion of macrophages or inhibition of matrix metalloproteinases (Mmps) leads to an accumulation of HSPCs in the AGM and a decrease in the colonization of haematopoietic organs. Finally, in vivo zymography demonstrates the function of primitive macrophages in extracellular matrix degradation, which allows HSPC migration through the AGM stroma, their intravasation, leading to the colonization of haematopoietic organs and the establishment of definitive haematopoiesis.

The Nell-1 Growth Factor Stimulates Bone Formation by Purified Human Perivascular Cells

PubMed Central

Zhang, Xinli; Péault, Bruno; Chen, Weiwei; Li, Weiming; Corselli, Mirko; James, Aaron W.; Lee, Min; Siu, Ronald K.; Shen, Pang; Zheng, Zhong; Shen, Jia; Kwak, Jinny; Zara, Janette N.; Chen, Feng; Zhang, Hong; Yin, Zack; Wu, Ben; Ting, Kang

2011-01-01

The search for novel sources of stem cells other than bone marrow mesenchymal stem cells (MSCs) for bone regeneration and repair has been a critical endeavor. We previously established an effective protocol to homogeneously purify human pericytes from multiple fetal and adult tissues, including adipose, bone marrow, skeletal muscle, and pancreas, and identified pericytes as a primitive origin of human MSCs. In the present study, we further characterized the osteogenic potential of purified human pericytes combined with a novel osteoinductive growth factor, Nell-1. Purified pericytes grown on either standard culture ware or human cancellous bone chip (hCBC) scaffolds exhibited robust osteogenic differentiation in vitro. Using a nude mouse muscle pouch model, pericytes formed significant new bone in vivo as compared to scaffold alone (hCBC). Moreover, Nell-1 significantly increased pericyte osteogenic differentiation, both in vitro and in vivo. Interestingly, Nell-1 significantly induced pericyte proliferation and was observed to have pro-angiogenic effects, both in vitro and in vivo. These studies suggest that pericytes are a potential new cell source for future efforts in skeletal regenerative medicine, and that Nell-1 is a candidate growth factor able to induce pericyte osteogenic differentiation. PMID:21615216

Neocortical layers I and II of the hedgehog (Erinaceus europaeus). I. Intrinsic organization.

PubMed

Valverde, F; Facal-Valverde, M V

1986-01-01

The intrinsic organization and interlaminar connections in neocortical layers I and II have been studied in adult hedgehogs (Erinaceus europaeus) using the Golgi method. Layer I contains a dense plexus of horizontal fibers, the terminal dendritic bouquets of pyramidal cells of layer II and of underlying layers, and varieties of intrinsic neurons. Four main types of cells were found in layer I. Small horizontal cells represent most probably persisting foetal horizontal cells described for other mammals. Large horizontal cells, tufted cells, and spinous horizontal cells were also found in this layer. Layer II contains primitive pyramidal cells representing the most outstanding feature of the neocortex of the hedgehog. Most pyramidal cells in layer II have two, three or more apical dendrites, richly covered by spines predominating over the basal dendrites. These cells resemble pyramidal cells found in the piriform cortex, hippocampus and other olfactory areas. It is suggested that the presence of these neurons reflects the retention of a primitive character in neocortical evolution. Cells with intrinsic axons were found among pyramidal cells in layer II. These have smooth dendrites penetrating layer I and local axons forming extremely complex terminal arborizations around the bodies and proximal dendritic portions of pyramidal cells. They most probably effect numerous axo-somatic contacts resembling basket cells. The similarity of some axonal terminals with the chandelier type of axonal arborization is discussed. Other varieties of cells located in deep cortical layers and having ascending axons for layers I and II were also studied. It is concluded that the two first neocortical layers represent a level of important integration in this primitive mammal.

Importance of Sox2 in maintenance of cell proliferation and multipotency of mesenchymal stem cells in low-density culture.

PubMed

Yoon, D S; Kim, Y H; Jung, H S; Paik, S; Lee, J W

2011-10-01

This study has aimed to repopulate 'primitive' cells from late-passage mesenchymal stem cells (MSCs) of poor multipotentiality and low cell proliferation rate, by simply altering plating density. Effects of low density culture compared t high density culture on late-passage bone marrow (BM)-derived MSCs and pluripotency markers of multipotentiality were investigated. Cell proliferation, gene expression, RNA interference and differentiation potential were assayed. We repopulated 'primitive' cells by replating late-passage MSCs at low density (17 cells/cm(2) ) regardless of donor age. Repopulated MSCs from low-density culture were smaller cells with spindle shaped morphology compared to MSCs from high-density culture. The latter had enhanced colony-forming ability, proliferation rate, and adipogenic and chondrogenic potential. Strong expression of osteogenic-related genes (Cbfa1, Dlx5, alkaline phosphatase and type Ι collagen) in late-passage MSCs was reduced by replating at low density, whereas expression of three pluripotency markers (Sox2, Nanog and Oct-4), Osterix and Msx2 reverted to levels of early-passage MSCs. Knockdown of Sox2 and Msx2 but not Nanog, using RNA interference, showed significant decrease in colony-forming ability. Specifically, knockdown of Sox2 significantly inhibited multipotentiality and cell proliferation. Our data suggest that plating density should be considered to be a critical factor for enrichment of 'primitive' cells from heterogeneous BM and that replicative senescence and multipotentiality of MSCs during in vitro expansion may be predominantly regulated through Sox2. © 2011 Blackwell Publishing Ltd.

Impact of modeled microgravity on migration, differentiation, and cell cycle control of primitive human hematopoietic progenitor cells.

PubMed

Plett, P Artur; Abonour, Rafat; Frankovitz, Stacy M; Orschell, Christie M

2004-08-01

Migration, proliferation, and differentiation of bone marrow (BM) hematopoietic stem cells (HSC) are important factors in maintaining hematopoietic homeostasis. Homeostatic control of erythrocytes and lymphocytes is perturbed in humans exposed to microgravity (micro-g), resulting in space flight-induced anemia and immunosuppression. We sought to determine whether any of these anomalies can be explained by micro-g-induced changes in migration, proliferation, and differentiation of human BM CD34+ cells, and whether such changes can begin to explain any of the shifts in hematopoietic homeostasis observed in astronauts. BM CD34+ cells were cultured in modeled micro-g (mmicro-g) using NASA's rotating wall vessels (RWV), or in control cultures at earth gravity for 2 to 18 days. Cells were harvested at different times and CD34+ cells assessed for migration potential, cell-cycle kinetics and regulatory proteins, and maturation status. Culture of BM CD34+ cells in RWV for 2 to 3 days resulted in a significant reduction of stromal cell-derived factor 1 (SDF-1alpha)-directed migration, which correlated with decreased expression of F-actin. Modeled micro-g induced alterations in cell-cycle kinetics that were characterized by prolonged S phase and reduced cyclin A expression. Differentiation of primitive CD34+ cells cultured for 14 to 18 days in RWV favored myeloid cell development at the expense of erythroid development, which was significantly reduced compared to controls. These results illustrate that mmicro-g significantly inhibits the migration potential, cell-cycle progression, and differentiation patterns of primitive BM CD34+ cells, which may contribute to some of the hematologic abnormalities observed in humans during space flight.

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ding, Ke, E-mail: dingke@med.uestc.edu.cn; Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072; Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibitedmore » a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering.« less

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation.

PubMed

Ding, Ke; Liu, Wen-Ying; Zeng, Qiang; Hou, Fang; Xu, Jian-Zhong; Yang, Zhong

2017-03-01

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering. Copyright © 2017 Elsevier Inc. All rights reserved.

Disruption of IKAROS activity in primitive chronic-phase CML cells mimics myeloid disease progression

PubMed Central

Beer, Philip A.; Knapp, David J. H. F.; Miller, Paul H.; Kannan, Nagarajan; Sloma, Ivan; Heel, Kathy; Babovic, Sonja; Bulaeva, Elizabeth; Rabu, Gabrielle; Terry, Jefferson; Druker, Brian J.; Loriaux, Marc M.; Loeb, Keith R.; Radich, Jerald P.; Erber, Wendy N.

2015-01-01

Without effective therapy, chronic-phase chronic myeloid leukemia (CP-CML) evolves into an acute leukemia (blast crisis [BC]) that displays either myeloid or B-lymphoid characteristics. This transition is often preceded by a clinically recognized, but biologically poorly characterized, accelerated phase (AP). Here, we report that IKAROS protein is absent or reduced in bone marrow blasts from most CML patients with advanced myeloid disease (AP or BC). This contrasts with primitive CP-CML cells and BCR-ABL1–negative acute myeloid leukemia blasts, which express readily detectable IKAROS. To investigate whether loss of IKAROS contributes to myeloid disease progression in CP-CML, we examined the effects of forced expression of a dominant-negative isoform of IKAROS (IK6) in CP-CML patients’ CD34+ cells. We confirmed that IK6 disrupts IKAROS activity in transduced CP-CML cells and showed that it confers on them features of AP-CML, including a prolonged increased output in vitro and in xenografted mice of primitive cells with an enhanced ability to differentiate into basophils. Expression of IK6 in CD34+ CP-CML cells also led to activation of signal transducer and activator of transcription 5 and transcriptional repression of its negative regulators. These findings implicate loss of IKAROS as a frequent step and potential diagnostic harbinger of progressive myeloid disease in CML patients. PMID:25370416

Tholeiitic basalt magmatism of Kilauea and Mauna Loa volcanoes of Hawaii

USGS Publications Warehouse

Murata, K.J.

1970-01-01

The primitive magmas of Kilauca and Mauna Loa are generated by partial melting of mantle peridotite at depths of -60 km or more. Results of high-pressure melting experiments indicate that the primitive melt must contain at least 20% MgO in order to have olivine as a liquidus mineral. The least fractionated lavas of both volcanoes have olivine (Fa13) on the liquidus at 1 atmosphere, suggesting that the only substance lost from the primitive melt, during a rather rapid ascent to the surface, is olivine. This relation allows the primitive composition to be computed by adding olivine to the composition of an erupted lava until total MgO is at least 20 percent. Although roughly similar, historic lavas of the two volcanoes show a consistent difference in composition. The primitive melt of Mauna Loa contains 20% more dissolved orthopyroxene, a high-temperature melting phase in the mantle, and is deficient in elements such as potassium, uranium, and niobium, which presumably occur in minor low-melting phases. Mauna Loa appears to be the older volcano, deriving its magma at higher temperature and greater depth from a more depleted source rock. ?? 1970 Springer-Verlag.

Tanespimycin in Treating Young Patients With Recurrent or Refractory Leukemia or Solid Tumors

ClinicalTrials.gov

2013-06-03

Childhood Chronic Myelogenous Leukemia; Childhood Desmoplastic Small Round Cell Tumor; Disseminated Neuroblastoma; Metastatic Childhood Soft Tissue Sarcoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

Technical design and system implementation of region-line primitive association framework

NASA Astrophysics Data System (ADS)

Wang, Min; Xing, Jinjin; Wang, Jie; Lv, Guonian

2017-08-01

Apart from regions, image edge lines are an important information source, and they deserve more attention in object-based image analysis (OBIA) than they currently receive. In the region-line primitive association framework (RLPAF), we promote straight-edge lines as line primitives to achieve powerful OBIAs. Along with regions, straight lines become basic units for subsequent extraction and analysis of OBIA features. This study develops a new software system called remote-sensing knowledge finder (RSFinder) to implement RLPAF for engineering application purposes. This paper introduces the extended technical framework, a comprehensively designed feature set, key technology, and software implementation. To our knowledge, RSFinder is the world's first OBIA system based on two types of primitives, namely, regions and lines. It is fundamentally different from other well-known region-only-based OBIA systems, such as eCogntion and ENVI feature extraction module. This paper has important reference values for the development of similarly structured OBIA systems and line-involved extraction algorithms of remote sensing information.

Molecular-Guided Therapy for Childhood Cancer

ClinicalTrials.gov

2017-07-07

Neuroblastoma; Medulloblastoma; Glioma; Ependymoma; Choroid Plexus Neoplasms; Craniopharyngioma; Dysembryoplastic Neuroepithelial Tumor; Meningioma; Primitive Neuroectodermal Tumors (PNETs); Germ Cell Tumors; Rhabdomyosarcoma; Non-rhabdomyosarcoma; Ewings Sarcoma; Osteosarcoma; Wilms Tumor; Renal Cell Carcinoma; Malignant Rhabdoid Tumor; Clear Cell Sarcoma; Liver Tumors

Essential roles for Cdx in murine primitive hematopoiesis.

PubMed

Brooke-Bisschop, Travis; Savory, Joanne G A; Foley, Tanya; Ringuette, Randy; Lohnes, David

2017-02-15

The Cdx transcription factors play essential roles in primitive hematopoiesis in the zebrafish where they exert their effects, in part, through regulation of hox genes. Defects in hematopoiesis have also been reported in Cdx mutant murine embryonic stem cell models, however, to date no mouse model reflecting the zebrafish Cdx mutant hematopoietic phenotype has been described. This is likely due, in part, to functional redundancy among Cdx members and the early lethality of Cdx2 null mutants. To circumvent these limitations, we used Cre-mediated conditional deletion to assess the impact of concomitant loss of Cdx1 and Cdx2 on murine primitive hematopoiesis. We found that Cdx1/Cdx2 double mutants exhibited defects in primitive hematopoiesis and yolk sac vasculature concomitant with reduced expression of several genes encoding hematopoietic transcription factors including Scl/Tal1. Chromatin immunoprecipitation analysis revealed that Scl was occupied by Cdx2 in vivo, and Cdx mutant hematopoietic yolk sac differentiation defects could be rescued by expression of exogenous Scl. These findings demonstrate critical roles for Cdx members in murine primitive hematopoiesis upstream of Scl. Copyright © 2017 Elsevier Inc. All rights reserved.

Human amnion epithelial cells expressing HLA-G as novel cell-based treatment for liver disease.

PubMed

Strom, Stephen C; Gramignoli, Roberto

2016-09-01

Despite routine liver transplantation and supporting medical therapies, thousands of patients currently wait for an organ and there is an unmet need for more refined and widely available regenerative strategies to treat liver diseases. Cell transplants attempt to maximize the potential for repair and/or regeneration in liver and other organs. Over 40years of laboratory pre-clinical research and 25years of clinical procedures have shown that certain liver diseases can be treated by the infusion of isolated cells (hepatocyte transplant). However, like organ transplants, hepatocyte transplant suffers from a paucity of tissues useful for cell production. Alternative sources have been investigated, yet with limited success. The tumorigenic potential of pluripotent stem cells together with their primitive level of hepatic differentiation, have limited the use of stem cell populations. Stem cell sources from human placenta, and the amnion tissue in particular are receiving renewed interest in the field of regenerative medicine. Unlike pluripotent stem cells, human amnion epithelial (AE) cells are easily available without ethical or religious concerns; they do not express telomerase and are not immortal or tumorigenic when transplanted. In addition, AE cells have been reported to express genes normally expressed in mature liver, when transplanted into the liver. Moreover, because of the possibility of an immune-privileged status related to their expression of HLA-G, it might be possible to transplant human AE cells without immunosuppression of the recipient. Copyright © 2016. Published by Elsevier Inc.

The Evolution of the Earliest Cells.

ERIC Educational Resources Information Center

Schopf, J. William

1978-01-01

Describes the unicellular microorganisms of three billion years ago. Explains how these primitive cells gave rise to biochemical systems and the present oxygen-rich atmosphere. Numerous diagrams, charts, and illustrations. (MA)

Cognitive functions of intracellular mechanisms for contextual amplification.

PubMed

Phillips, William A

2017-03-01

Evidence for the hypothesis that input to the apical tufts of neocortical pyramidal cells plays a central role in cognition by amplifying their responses to feedforward input is reviewed. Apical tufts are electrically remote from the soma, and their inputs come from diverse sources including direct feedback from higher cortical regions, indirect feedback via the thalamus, and long-range lateral connections both within and between cortical regions. This suggests that input to tuft dendrites may amplify the cell's response to basal inputs that they receive via layer 4 and which have synapses closer to the soma. ERP data supporting this inference is noted. Intracellular studies of apical amplification (AA) and of disamplification by inhibitory interneurons targeted only at tufts are reviewed. Cognitive processes that have been related to them by computational, electrophysiological, and psychopathological studies are then outlined. These processes include: figure-ground segregation and Gestalt grouping; contextual disambiguation in perception and sentence comprehension; priming; winner-take-all competition; attention and working memory; setting the level of consciousness; cognitive control; and learning. It is argued that theories in cognitive neuroscience should not assume that all neurons function as integrate-and-fire point processors, but should use the capabilities of cells with distinct sites of integration for driving and modulatory inputs. Potentially 'unifying' theories that depend upon these capabilities are reviewed. It is concluded that evolution of the primitives of AA and disamplification in neocortex may have extended cognitive capabilities beyond those built from the long-established primitives of excitation, inhibition, and disinhibition. Copyright © 2015 Elsevier Inc. All rights reserved.

Olivine and chromian spinel in primitive calc-alkaline and tholeiitic lavas from the southernmost cascade range, California: A reflection of relative fertility of the source

USGS Publications Warehouse

Clynne, M.A.; Borg, L.E.

1997-01-01

Chromian spinel and coexisting olivine phenocrysts from a geochemically diverse suite of primitive tholeiitic and calc-alkaline basalts and magnesian andesites from the Lassen region, in the southernmost Cascade Range, in California, show that the sub-arc mantle is zoned. Depleted calc-alkaline basalts and magnesian andesites erupt in the forearc region, and calc-alkaline basalts contain increasing abundances of incompatible elements toward the backarc. High-alumina olivine tholeiites erupt from the arc and backarc areas. Olivine from all these lavas displays a limited compositional range, from Fo86 to Fo91, and crystallized at high temperature, generally 1225-1275??C. Chromian spinel trapped in the olivine phenocrysts displays a large range of composition: Cr# values span the range 9-76. Excess Al in the spinel relative to that in 1-atm spinel suggests that it crystallized at elevated pressure. The phenocrysts in these lavas are in equilibrium with their host liquids. The full range of Cr# of the spinel compositions cannot be explained by differentiation or variable pressure, variations in f(O2), subsolidus equilibration or variations in degree of partial melting of a single peridotitic source. Rather, the systematic compositional differences among phenocrysts in these primitive lavas result from bulk chemical variability in their mantle sources. Correlations between spinel and host-rock compositions support the assertion that the geochemical diversity of Lassen basalts reflects the relative fertility of their mantle sources.

Ultrastrukturelle Untersuchungen zur Morphologie und Genese der Spermien von Archaeogastropoda

NASA Astrophysics Data System (ADS)

Kohnert, R.; Storch, V.

1983-03-01

The sperm cells of Patella coerulea (Patellacea), Monodonta turbinata, and Gibbula tumida (Trochacea) were investigated by means of transmission electron microscopy. They belong to the primitive type (sensu Franzén) and have more features in common with primitive Bivalvia sperms than with Neritacea. Their head contains an apical acrosome and a roundish nucleus followed by 4 or 5 mitochondria and a centriolar apparatus which consists of two centrioles, one of which bears a flagellum. The sperm cells of Monodonta and Gibbula are very similar to each other and differ mainly in size; Patella exhibits more differences (very small acrosome, subacrosomal space, variable number of spherical mitochondria (origin of spermic dimorphism ?). The development of the sperm cells shows no peculiarities.

Tazemetostat in Treating Patients With Relapsed or Refractory Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With EZH2, SMARCB1, or SMARCA4 Gene Mutations (A Pediatric MATCH Treatment Trial)

ClinicalTrials.gov

2018-06-20

Advanced Malignant Solid Neoplasm; Ann Arbor Stage III Childhood Hodgkin Lymphoma; Ann Arbor Stage III Childhood Non-Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Non-Hodgkin Lymphoma; Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; EZH2 Gain of Function; EZH2 Gene Mutation; Histiocytosis; Loss of BRG1 Protein Expression; Loss of INI 1 Protein Expression; Low Grade Glioma; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Childhood Ependymoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma; Recurrent Glioma; Recurrent Hepatoblastoma; Recurrent Hodgkin Lymphoma; Recurrent Langerhans Cell Histiocytosis; Recurrent Malignant Germ Cell Tumor; Recurrent Malignant Glioma; Recurrent Malignant Solid Neoplasm; Recurrent Medulloblastoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Peripheral Primitive Neuroectodermal Tumor; Recurrent Rhabdoid Tumor; Recurrent Rhabdomyosarcoma; Recurrent Soft Tissue Sarcoma; Refractory Central Nervous System Neoplasm; Refractory Hodgkin Lymphoma; Refractory Langerhans Cell Histiocytosis; Refractory Malignant Germ Cell Tumor; Refractory Malignant Glioma; Refractory Medulloblastoma; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Refractory Osteosarcoma; Refractory Peripheral Primitive Neuroectodermal Tumor; Refractory Rhabdoid Tumor; Refractory Soft Tissue Sarcoma; Rhabdoid Tumor; SMARCA4 Gene Inactivation; SMARCB1 Gene Inactivation; Stage III Soft Tissue Sarcoma AJCC v7; Stage IV Soft Tissue Sarcoma AJCC v7; Wilms Tumor

The Nature and Origin of Interplanetary Dust: High Temperature Components

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

The specific parent bodies of individual interplanetary dust particles (IDPs) are un-known, but the anhydrous chondritic-porous (CP) sub-set has been linked directly to cometary sources [1]. The CP IDPs escaped the thermal processing and water-rock interactions that have severely modified or destroyed the original mineralogy of primitive meteorites. Their origin in the outer regions of the solar system suggests they should retain primitive chemical and physical characteristics from the earliest stages of solar system formation (including abundant presolar materials). Indeed, CP IDPs are the most primitive extraterrestrial materials available for laboratory studies based on their unequilibrated mineralogy [2], high concentrations of carbon, nitrogen and volatile trace elements relative to CI chondrites [3, 4, 5], presolar hydrogen and nitrogen isotopic signatures [6, 7] and abundant presolar silicates [8].

Studying the hopping parameters of half-Heusler NaAuS using maximally localized Wannier function

NASA Astrophysics Data System (ADS)

Sihi, Antik; Lal, Sohan; Pandey, Sudhir K.

2018-04-01

Here, the electronic behavior of half-Heusler NaAuS is studied using PBEsol exchange correlation functional by plotting the band structure curve. These bands are reproduced using maximally localized Wannier function using WANNIER90. Tight-binding bands are nicely matched with density functional theory bands. By fitting the tight-binding model, hopping parameter for NaAuS is obtained by including Na 2s, 2p, Au 6s, 5p, 5d and S 3s, 3p orbitals within the energy interval of -5 to 16 eV around the Fermi level. In present study, hopping integrals for NaAuS are computed for the first primitive unit cell atoms as well as the first nearest neighbor primitive unit cell. The most dominating hopping integrals are found for Na (3s) - S (3s), Na (2px) - S (2px), Au (6s) - S (3px), Au (6s) - S (3py) and Au (6s) - S (3pz) orbitals. The hopping integrals for the first nearest neighbor primitive unit cell are also discussed in this manuscript. In future, these hopping integrals are very important to find the topological invariant for NaAuS compound.

Enforced expression of KDR receptor promotes proliferation, survival and megakaryocytic differentiation of TF1 progenitor cell line.

PubMed

Coppola, S; Narciso, L; Feccia, T; Bonci, D; Calabrò, L; Morsilli, O; Gabbianelli, M; De Maria, R; Testa, U; Peschle, C

2006-01-01

Vascular endothelial growth factor (VEGF) receptor-2/kinase insert domain-containing receptor (KDR) is expressed in primitive hematopoietic cells, in megakaryocytes and platelets. In primitive hematopoiesis KDR mediates cell survival via autocrine VEGF, while its effect on cell growth and differentiation has not been elucidated. We induced enforced KDR expression in the granulocyte macrophage-colony-stimulating factor (GM-CSF)-dependent TF1 progenitor cell line (TF1-KDR), treated the cells with VEGF and analyzed their response. In GM-CSF-deprived cells, VEGF induces cell proliferation and protection against apoptosis, followed by enhanced expression of megakaryocytic (MK) markers. Combined with GM-CSF, VEGF induces a mild proliferative stimulus, followed by cell adherence, accumulation in G0/G1, massive MK differentiation and Fas-mediated apoptosis. Accordingly, we observed that MK-differentiating cells, derived from hematopoietic progenitors, produce VEGF, express KDR, inhibition of which reduces MK differentiation, indicating a key role of KDR in megakaryopoiesis. In conclusion, TF1-KDR cells provide a reliable model to investigate the biochemical and molecular mechanisms underlying hematopoietic progenitor proliferation, survival and MK differentiation.

PRIMitive Asteroids Spectroscopic Survey - PRIMASS: First Results

NASA Astrophysics Data System (ADS)

de Leon, Julia; Pinilla-Alonso, Noemi; Campins, Humberto; Lorenzi, Vania; Licandro, Javier; Morate, David; Tanga, Paolo; Cellino, Alberto; Delbo, Marco

2015-11-01

NASA OSIRIS-REx and JAXA Hayabusa 2 sample-return missions have targeted two near-Earth asteroids: (101955) Bennu and (162173) 1999 JU3, respectively. These are primitive asteroids that are believed to originate in the inner belt, where five distinct sources have been identified: four primitive collisional families (Polana, Erigone, Sulamitis, and Clarissa), and a population of low-albedo and low-inclination background asteroids. Identifying and characterizing the populations from which these two NEAs might originate will enchance the science return of the two missions.With this main objective in mind, we initiated in 2010 a spectroscopic survey in the visible and the near-infrared to characterize the primitive collisional families in the inner belt and the low-albedo background population. This is the PRIMitive Asteroids Spectroscopic Survey - PRIMASS. So far we have obtained more than 200 spectra using telescopes located at different observatories. PRIMASS uses a variety of ground based facilities. Most of the spectra have been obtained using the 10.4m Gran Telescopio Canarias (GTC), and the 3.6m Telescopio Nazionale Galileo (TNG), both located at the El Roque de los Muchachos Observatory (La Palma, Spain), and the 3.0m NASA Infrared Telescope Facility on Mauna Kea (Hawai, USA).We present the first results from our on-going survey (de Leon et al. 2015; Pinilla-Alonso et al. 2015; Morate et al. 2015), focused on the Polana and the Erigone primitive families, with visible and near-infrared spectra of more than 200 objects, most of them with no previous spectroscopic data. Our survey is already the largest database of primitive asteroids spectra, and we keep obtaining data on the Sulamitis and the Clarissa families, as well as on the background low-albedo population.

Induction of multipotential hematopoietic progenitors from human pluripotent stem cells via re-specification of lineage-restricted precursors

PubMed Central

Doulatov, Sergei; Vo, Linda T.; Chou, Stephanie S.; Kim, Peter G.; Arora, Natasha; Li, Hu; Hadland, Brandon K.; Bernstein, Irwin D.; Collins, James J.; Zon, Leonard I.; Daley, George Q.

2013-01-01

Summary Human pluripotent stem cells (hPSCs) represent a promising source of patient-specific cells for disease modeling, drug screens, and cellular therapies. However, the inability to derive engraftable human hematopoietic stem and progenitor (HSPCs) has limited their characterization to in vitro assays. We report a strategy to re-specify lineage-restricted CD34+CD45+ myeloid precursors derived from hPSCs into multilineage progenitors that can be expanded in vitro and engraft in vivo. HOXA9, ERG, and RORA conferred self-renewal and multilineage potential in vitro and maintained primitive CD34+CD38− cells. Screening cells via transplantation revealed that two additional factors, SOX4 and MYB, were required for engraftment. Progenitors specified with all five factors gave rise to reproducible short-term engraftment with myeloid and erythroid lineages. Erythroid precursors underwent hemoglobin switching in vivo, silencing embryonic and activating adult globin expression. Our combinatorial screening approach establishes a strategy for obtaining transcription factor-mediated engraftment of blood progenitors from human pluripotent cells. PMID:24094326

Dual mTORC2/mTORC1 targeting results in potent suppressive effects on acute myeloid leukemia (AML) progenitors*

PubMed Central

Altman, Jessica K.; Sassano, Antonella; Kaur, Surinder; Glaser, Heather; Kroczynska, Barbara; Redig, Amanda J.; Russo, Suzanne; Barr, Sharon; Platanias, Leonidas C.

2011-01-01

Purpose To determine whether mTORC2 and RI-mTORC1 complexes are present in AML cells and to examine the effects of dual mTORC2/mTORC1 inhibition on primitive AML leukemic progenitors. Experimental Design Combinations of different experimental approaches were used, including immunoblotting to detect phosphorylated/activated forms of elements of the mTOR pathway in leukemic cell lines and primary AML blasts; cell proliferation assays; direct assessment of mRNA translation in polysomal fractions of leukemic cells; and clonogenic assays in methylcellulose to evaluate leukemic progenitor colony formation. Results mTORC2 complexes are active in AML cells and play critical roles in leukemogenesis. Rapamycin insensitive (RI) mTORC1 complexes are also formed and regulate the activity of the translational repressor 4E-BP1 in AML cells. OSI-027, blocks mTORC1 and mTORC2 activities and suppresses mRNA translation of cyclin D1 and other genes that mediate proliferative responses in AML cells. Moreover, OSI-027 acts as a potent suppressor of primitive leukemic precursors from AML patients and is much more effective than rapamycin in eliciting antileukemic effects in vitro. Conclusions Dual targeting of mTORC2 and mTORC1 results in potent suppressive effects on primitive leukemic progenitors from AML patients. Inhibition of the mTOR catalytic site with OSI-027 results in suppression of both mTORC2 and RI-mTORC1 complexes and elicits much more potent antileukemic responses than selective mTORC1 targeting with rapamycin. PMID:21415215

Efficient mixing of the solar nebula from uniform Mo isotopic composition of meteorites.

PubMed

Becker, Harry; Walker, Richard J

2003-09-11

The abundances of elements and their isotopes in our Galaxy show wide variations, reflecting different nucleosynthetic processes in stars and the effects of Galactic evolution. These variations contrast with the uniformity of stable isotope abundances for many elements in the Solar System, which implies that processes efficiently homogenized dust and gas from different stellar sources within the young solar nebula. However, isotopic heterogeneity has been recognized on the subcentimetre scale in primitive meteorites, indicating that these preserve a compositional memory of their stellar sources. Small differences in the abundance of stable molybdenum isotopes in bulk rocks of some primitive and differentiated meteorites, relative to terrestrial Mo, suggest large-scale Mo isotopic heterogeneity between some inner Solar System bodies, which implies physical conditions that did not permit efficient mixing of gas and dust. Here we report Mo isotopic data for bulk samples of primitive and differentiated meteorites that show no resolvable deviations from terrestrial Mo. This suggests efficient mixing of gas and dust in the solar nebula at least to 3 au from the Sun, possibly induced by magnetohydrodynamic instabilities. These mixing processes must have occurred before isotopic fractionation of gas-phase elements and volatility-controlled chemical fractionations were established.

The Composition and Organization of Cytoplasm in Prebiotic Cells

PubMed Central

Trevors, Jack T.

2011-01-01

This article discusses the hypothesized composition and organization of cytoplasm in prebiotic cells from a theoretical perspective and also based upon what is currently known about bacterial cytoplasm. It is unknown if the first prebiotic, microscopic scale, cytoplasm was initially contained within a primitive, continuous, semipermeable membrane, or was an uncontained gel substance, that later became enclosed by a continuous membrane. Another possibility is that the first cytoplasm in prebiotic cells and a primitive membrane organized at the same time, permitting a rapid transition to the first cell(s) capable of growth and division, thus assisting with the emergence of life on Earth less than a billion years after the formation of the Earth. It is hypothesized that the organization and composition of cytoplasm progressed initially from an unstructured, microscopic hydrogel to a more complex cytoplasm, that may have been in the volume magnitude of about 0.1–0.2 μm3 (possibly less if a nanocell) prior to the first cell division. PMID:21673913

Lysophosphatidic acid acts as a nutrient-derived developmental cue to regulate early hematopoiesis

PubMed Central

Li, Haisen; Yue, Rui; Wei, Bin; Gao, Ge; Du, Jiulin; Pei, Gang

2014-01-01

Primitive hematopoiesis occurs in the yolk sac blood islands during vertebrate embryogenesis, where abundant phosphatidylcholines (PC) are available as important nutrients for the developing embryo. However, whether these phospholipids also generate developmental cues to promote hematopoiesis is largely unknown. Here, we show that lysophosphatidic acid (LPA), a signaling molecule derived from PC, regulated hemangioblast formation and primitive hematopoiesis. Pharmacological and genetic blockage of LPA receptor 1 (LPAR1) or autotoxin (ATX), a secretory lysophospholipase that catalyzes LPA production, inhibited hematopoietic differentiation of mouse embryonic stem cells and impaired the formation of hemangioblasts. Mechanistic experiments revealed that the regulatory effect of ATX-LPA signaling was mediated by PI3K/Akt-Smad pathway. Furthermore, during in vivo embryogenesis in zebrafish, LPA functioned as a developmental cue for hemangioblast formation and primitive hematopoiesis. Taken together, we identified LPA as an important nutrient-derived developmental cue for primitive hematopoiesis as well as a novel mechanism of hemangioblast regulation. PMID:24829209

Lysophosphatidic acid acts as a nutrient-derived developmental cue to regulate early hematopoiesis.

PubMed

Li, Haisen; Yue, Rui; Wei, Bin; Gao, Ge; Du, Jiulin; Pei, Gang

2014-06-17

Primitive hematopoiesis occurs in the yolk sac blood islands during vertebrate embryogenesis, where abundant phosphatidylcholines (PC) are available as important nutrients for the developing embryo. However, whether these phospholipids also generate developmental cues to promote hematopoiesis is largely unknown. Here, we show that lysophosphatidic acid (LPA), a signaling molecule derived from PC, regulated hemangioblast formation and primitive hematopoiesis. Pharmacological and genetic blockage of LPA receptor 1 (LPAR1) or autotoxin (ATX), a secretory lysophospholipase that catalyzes LPA production, inhibited hematopoietic differentiation of mouse embryonic stem cells and impaired the formation of hemangioblasts. Mechanistic experiments revealed that the regulatory effect of ATX-LPA signaling was mediated by PI3K/Akt-Smad pathway. Furthermore, during in vivo embryogenesis in zebrafish, LPA functioned as a developmental cue for hemangioblast formation and primitive hematopoiesis. Taken together, we identified LPA as an important nutrient-derived developmental cue for primitive hematopoiesis as well as a novel mechanism of hemangioblast regulation. © 2014 The Authors.

Morphology of isolated mouse inner cell masses developing in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiley, L.M.; Spindle, A.I.; Pedersen, R.A.

1978-01-01

The purpose of this study was to examine the developmental capacity of the mouse inner cell mass (ICM) in the absence of the trophoblast. ICMs were isolated from blastocysts by immunosurgery and cultured under conditions that support egg cylinder formation by intact blastocysts. After 2 or 3 days of culture, the ICMs consisted of an outer layer of endoderm and an inner layer of ectoderm that had cavitated centrally. By 4 or 5 days of culture, 25 to 60% of these ICMs had developed into paired cysts, apparently by secondary cavity formation. The inner cell layer surrounding this secondary cavitymore » resembled the extraembryonic ectoderm of cultured egg cylinders. By 6 days of culture, 60% of the ICMs had expanded into yolk sac-like structures that subsequently produced capillaries containing blood cells. The ICMs appeared to develop mesoderm in two distinct ways. A few of them developed mesoderm as a third layer of cells in the cleft separating endoderm and ectoderm, presumably by migrating from the inner, ectodermal layer, through the primitive streak, as in the intact egg cylinder. In the rest of the ICMs the embryonic ectoderm gradually differentiated into mesoderm while still in the inner layer, without primitive streak formation. We suggest, therefore, that the continuous presence of the trophoblast or of its derivatives is not required for the cytodifferentiation of mesoderm although it may be important in establishing embryonic polarity or in providinginductive signals necessary for the morphogenetic aspects of mesoderm differentiation, specifically primitive streak formation.« less

The ECM moves during primitive streak formation--computation of ECM versus cellular motion.

PubMed

Zamir, Evan A; Rongish, Brenda J; Little, Charles D

2008-10-14

Galileo described the concept of motion relativity--motion with respect to a reference frame--in 1632. He noted that a person below deck would be unable to discern whether the boat was moving. Embryologists, while recognizing that embryonic tissues undergo large-scale deformations, have failed to account for relative motion when analyzing cell motility data. A century of scientific articles has advanced the concept that embryonic cells move ("migrate") in an autonomous fashion such that, as time progresses, the cells and their progeny assemble an embryo. In sharp contrast, the motion of the surrounding extracellular matrix scaffold has been largely ignored/overlooked. We developed computational/optical methods that measure the extent embryonic cells move relative to the extracellular matrix. Our time-lapse data show that epiblastic cells largely move in concert with a sub-epiblastic extracellular matrix during stages 2 and 3 in primitive streak quail embryos. In other words, there is little cellular motion relative to the extracellular matrix scaffold--both components move together as a tissue. The extracellular matrix displacements exhibit bilateral vortical motion, convergence to the midline, and extension along the presumptive vertebral axis--all patterns previously attributed solely to cellular "migration." Our time-resolved data pose new challenges for understanding how extracellular chemical (morphogen) gradients, widely hypothesized to guide cellular trajectories at early gastrulation stages, are maintained in this dynamic extracellular environment. We conclude that models describing primitive streak cellular guidance mechanisms must be able to account for sub-epiblastic extracellular matrix displacements.

The neonatal marmoset monkey ovary is very primitive exhibiting many oogonia

PubMed Central

Fereydouni, B; Drummer, C; Aeckerle, N; Schlatt, S; Behr, R

2014-01-01

Oogonia are characterized by diploidy and mitotic proliferation. Human and mouse oogonia express several factors such as OCT4, which are characteristic of pluripotent cells. In human, almost all oogonia enter meiosis between weeks 9 and 22 of prenatal development or undergo mitotic arrest and subsequent elimination from the ovary. As a consequence, neonatal human ovaries generally lack oogonia. The same was found in neonatal ovaries of the rhesus monkey, a representative of the old world monkeys (Catarrhini). By contrast, proliferating oogonia were found in adult prosimians (now called Strepsirrhini), which is a group of ‘lower’ primates. The common marmoset monkey (Callithrix jacchus) belongs to the new world monkeys (Platyrrhini) and is increasingly used in reproductive biology and stem cell research. However, ovarian development in the marmoset monkey has not been widely investigated. Herein, we show that the neonatal marmoset ovary has an extremely immature histological appearance compared with the human ovary. It contains numerous oogonia expressing the pluripotency factors OCT4A, SALL4, and LIN28A (LIN28). The pluripotency factor-positive germ cells also express the proliferation marker MKI67 (Ki-67), which has previously been shown in the human ovary to be restricted to premeiotic germ cells. Together, the data demonstrate the primitiveness of the neonatal marmoset ovary compared with human. This study may introduce the marmoset monkey as a non-human primate model to experimentally study the aspects of primate primitive gonad development, follicle assembly, and germ cell biology in vivo. PMID:24840529

All of the human beta-type globin genes compete for LCR enhancer activity in embryonic erythroid cells of yeast artificial chromosome transgenic mice.

PubMed

Okamura, Eiichi; Matsuzaki, Hitomi; Campbell, Andrew D; Engel, James Douglas; Fukamizu, Akiyoshi; Tanimoto, Keiji

2009-12-01

In primitive erythroid cells of human beta-globin locus transgenic mice (TgM), the locus control region (LCR)-proximal epsilon- and gamma-globin genes are transcribed, whereas the distal delta- and beta-globin genes are silent. It is generally accepted that the beta-globin gene is competitively suppressed by gamma-globin gene expression at this developmental stage. Previously, however, we observed that epsilon-globin gene expression was severely attenuated when its distance from the LCR was extended, implying that beta-globin gene might also be silenced because of its great distance from the LCR. Here, to clarify the beta-globin gene silencing mechanism, we established TgM lines carrying either gamma- or epsilon- plus gamma-globin promoter deletions, without significantly altering the distance between the beta-globin gene and the LCR. Precocious expression of delta- and beta-globin genes was observed in primitive erythroid cells of mutant, but not wild-type TgM, which was most evident when both the epsilon and gamma promoters were deleted. Thus, we clearly demonstrated that the repression of the delta- and beta-globin genes in primitive erythroid cells is dominated by competitive silencing by the epsilon- and gamma-globin gene promoters, and that epsilon- and the other beta-like globin genes might be activated by two distinct mechanisms by the LCR.

SIRT1 deficiency compromises mouse embryonic stem cell hematopoietic differentiation, and embryonic and adult hematopoiesis in the mouse

PubMed Central

Ou, Xuan; Chae, Hee-Don; Wang, Rui-Hong; Shelley, William C.; Cooper, Scott; Taylor, Tammi; Kim, Young-June; Deng, Chu-Xia; Yoder, Mervin C.

2011-01-01

SIRT1 is a founding member of a sirtuin family of 7 proteins and histone deacetylases. It is involved in cellular resistance to stress, metabolism, differentiation, aging, and tumor suppression. SIRT1−/− mice demonstrate embryonic and postnatal development defects. We examined hematopoietic and endothelial cell differentiation of SIRT1−/− mouse embryonic stem cells (ESCs) in vitro, and hematopoietic progenitors in SIRT1+/++/−, and −/− mice. SIRT1−/− ESCs formed fewer mature blast cell colonies. Replated SIRT1−/− blast colony-forming cells demonstrated defective hematopoietic potential. Endothelial cell production was unaltered, but there were defects in formation of a primitive vascular network from SIRT1−/−-derived embryoid bodies. Development of primitive and definitive progenitors derived from SIRT1−/− ESCs were also delayed and/or defective. Differentiation delay/defects were associated with delayed capacity to switch off Oct4, Nanog and Fgf5 expression, decreased β-H1 globin, β-major globin, and Scl gene expression, and reduced activation of Erk1/2. Ectopic expression of SIRT1 rescued SIRT1−/− ESC differentiation deficiencies. SIRT1−/− yolk sacs manifested fewer primitive erythroid precursors. SIRT1−/− and SIRT1+/− adult marrow had decreased numbers and cycling of hematopoietic progenitors, effects more apparent at 5%, than at 20%, oxygen tension, and these progenitors survived less well in vitro under conditions of delayed growth factor addition. This suggests a role for SIRT1 in ESC differentiation and mouse hematopoiesis. PMID:20966168

Growth of continental crust: Clues from Nd isotopes and Nb-Th relationships in mantle-derived magmas

NASA Astrophysics Data System (ADS)

Arndt, N. T.; Chauvel, C.; Jochum, K.-P.; Gruau, G.; Hofmann, A. W.

Isotope and trace element geochemistry of Precambrian mantle derived rocks and implications for the formation of the continental crust is discussed. Epsilon Nd values of Archean komatiites are variable, but range up to at least +5, suggesting that the Archean mantle was heterogeneous and, in part, very depleted as far back as 3.4 to 3.5 Ga. This may be taken as evidence for separation of continental crust very early in Earth history. If these komatiite sources were allowed to evolve in a closed system, they would produce modern day reservoirs with much higher epsilon Nd values than is observed. This implies recycling of some sort of enriched material, perhaps subducted sediments, although other possibilities exist. Archean volcanics show lower Nb/Th than modern volcanics, suggesting a more primitive mantle source than that observed nowadays. However, Cretaceous komatiites from Gorgona island have similar Nb/Th to Archean volcanics, indicating either the Archean mantle source was indeed more primitive, or Archean magmas were derived from a deep ocean island source like that proposed for Gorgona.

Growth of continental crust: Clues from Nd isotopes and Nb-Th relationships in mantle-derived magmas

NASA Technical Reports Server (NTRS)

Arndt, N. T.; Chauvel, C.; Jochum, K.-P.; Gruau, G.; Hofmann, A. W.

1988-01-01

Isotope and trace element geochemistry of Precambrian mantle derived rocks and implications for the formation of the continental crust is discussed. Epsilon Nd values of Archean komatiites are variable, but range up to at least +5, suggesting that the Archean mantle was heterogeneous and, in part, very depleted as far back as 3.4 to 3.5 Ga. This may be taken as evidence for separation of continental crust very early in Earth history. If these komatiite sources were allowed to evolve in a closed system, they would produce modern day reservoirs with much higher epsilon Nd values than is observed. This implies recycling of some sort of enriched material, perhaps subducted sediments, although other possibilities exist. Archean volcanics show lower Nb/Th than modern volcanics, suggesting a more primitive mantle source than that observed nowadays. However, Cretaceous komatiites from Gorgona island have similar Nb/Th to Archean volcanics, indicating either the Archean mantle source was indeed more primitive, or Archean magmas were derived from a deep ocean island source like that proposed for Gorgona.

The birth of embryonic pluripotency

PubMed Central

Boroviak, Thorsten; Nichols, Jennifer

2014-01-01

Formation of a eutherian mammal requires concurrent establishment of embryonic and extraembryonic lineages. The functions of the trophectoderm and primitive endoderm are to enable implantation in the maternal uterus, axis specification and delivery of nutrients. The pluripotent epiblast represents the founding cell population of the embryo proper, which is protected from ectopic and premature differentiation until it is required to respond to inductive cues to form the fetus. While positional information plays a major role in specifying the trophoblast lineage, segregation of primitive endoderm from epiblast depends upon gradual acquisition of transcriptional identity, directed but not initiated by fibroblast growth factor (FGF) signalling. Following early cleavage divisions and formation of the blastocyst, cells of the inner cell mass lose totipotency. Developing epiblast cells transiently attain the state of naive pluripotency and competence to self-renew in vitro as embryonic stem cells and in vivo by means of diapause. This property is lost after implantation as the epiblast epithelializes and becomes primed in preparation for gastrulation and subsequent organogenesis. PMID:25349450

The Modern Primitives: Applying New Technological Approaches to Explore the Biology of the Earliest Red Blood Cells

PubMed Central

Fraser, Stuart T.

2013-01-01

One of the most critical stages in mammalian embryogenesis is the independent production of the embryo's own circulating, functional red blood cells. Correspondingly, erythrocytes are the first cell type to become functionally mature during embryogenesis. Failure to achieve this invariably leads to in utero lethality. The recent application of technologies such as transcriptome analysis, flow cytometry, mutant embryo analysis, and transgenic fluorescent gene expression reporter systems has shed new light on the distinct erythroid lineages that arise early in development. Here, I will describe the similarities and differences between the distinct erythroid populations that must form for the embryo to survive. While much of the focus of this review will be the poorly understood primitive erythroid lineage, a discussion of other erythroid and hematopoietic lineages, as well as the cell types making up the different niches that give rise to these lineages, is essential for presenting an appropriate developmental context of these cells. PMID:24222861

Primitive control of cellular metabolism

NASA Technical Reports Server (NTRS)

Mitz, M. A.

1974-01-01

It is pointed out that control substances must have existed from the earliest times in the evolution of life and that the same control mechanisms must exist today. The investigation reported is concerned with the concept that carbon dioxide is a primitive regulator of cell function. The effects of carbon dioxide on cellular materials are examined, taking into account questions of solubilization, dissociation, changes of charge, stabilization, structural changes, wettability, the exclusion of other gases, the activation of compounds, changes in plasticity, and changes in membrane permeability.

Expression, crystallization and preliminary crystallographic analysis of the extracellular IgV-like domain of the human natural killer cell inhibitory receptor p75/AIRM1.

PubMed

Dimasi, Nazzareno; Moretta, Lorenzo; Biassoni, Roberto; Mariuzza, Roy A

2003-10-01

p75/AIRM1 (Siglec-7) is a sialic acid-binding Ig-like lectin recently identified as an inhibitory receptor on natural killer cells. The expression, in vitro folding, circular-dichroism spectroscopy, crystallization and preliminary X-ray characterization of the Ig-V like domain of p75/AIRM1 are reported. X-ray data were collected from a single crystal at 100 K, with a maximum useful diffraction pattern extending to 1.45 A resolution on a synchrotron source. The crystal belongs to a primitive monoclinic space group, with unit-cell parameters a = 32.65, b = 49.72, c = 39.79 A, alpha = gamma = 90, beta = 113 degrees. The systematic absences indicate that the space group is P2(1). Assuming one molecule per asymmetric unit, V(M) (the Matthews coefficient) was calculated to be 1.879 A(3) Da(-1) and the solvent content was estimated to be 32.01%.

Friend of GATA (FOG) Interacts with the Nucleosome Remodeling and Deacetylase Complex (NuRD) to Support Primitive Erythropoiesis in Xenopus laevis

PubMed Central

Mimoto, Mizuho S.; Christian, Jan L.

2012-01-01

Friend of GATA (FOG) plays many diverse roles in adult and embryonic hematopoiesis, however the mechanisms by which it functions and the roles of potential interaction partners are not completely understood. Previous work has shown that overexpression of FOG in Xenopus laevis causes loss of blood suggesting that in contrast to its role in mammals, FOG might normally function to repress erythropoiesis in this species. Using loss-of-function analysis, we demonstrate that FOG is essential to support primitive red blood cell (RBC) development in Xenopus. Moreover, we show that it is specifically required to prevent excess apoptosis of circulating primitive RBCs and that in the absence of FOG, the pro-apoptotic gene Bim-1 is strongly upregulated. To identify domains of FOG that are essential for blood development and, conversely, to begin to understand the mechanism by which overexpressed FOG represses primitive erythropoiesis, we asked whether FOG mutants that are unable to interact with known co-factors retain their ability to rescue blood formation in FOG morphants and whether they repress erythropoiesis when overexpressed in wild type embryos. We find that interaction of FOG with the Nucleosome Remodeling and Deacetylase complex (NuRD), but not with C-terminal Binding Protein, is essential for normal primitive RBC development. In contrast, overexpression of all mutant and wild type constructs causes a comparable repression of primitive erythropoiesis. Together, our data suggest that a requirement for FOG and its interaction with NuRD during primitive erythropoiesis are conserved in Xenopus and that loss of blood upon FOG overexpression is due to a dominant-interfering effect. PMID:22235346

Oparin's coacervates as an important milestone in chemical evolution

NASA Astrophysics Data System (ADS)

Kolb, Vera M.

2015-09-01

Although Oparin's coacervate model for the origin of life by chemical evolution is almost 100 years old, it is still valid. However, the structure of his originally proposed coacervate is not considered prebiotic, based on some recent developments in prebiotic chemistry. We have remedied this deficiency of the Oparin's model, by substituting his coacervate with a prebiotically feasible one. Oparin's coacervates are aqueous structures, but have a boundary with the rest of the aqueous medium. They exhibit properties of self-replication, and provide a path to a primitive metabolism, via chemical competition and thus a primitive selection. Thus, coacervates are good models for proto-cells. We review here some salient points of Oparin's model and address also some philosophical views on the beginning of natural selection in primitive chemical systems.

The composition of the primitive atmosphere and the synthesis of organic compounds on the early Earth

NASA Technical Reports Server (NTRS)

Bada, J. L.; Miller, S. L.

1985-01-01

The generally accepted theory for the origin of life on the Earth requires that a large variety of organic compounds be present to form the first living organisms and to provide the energy sources for primitive life either directly or through various fermentation reactions. This can provide a strong constraint on discussions of the formation of the Earth and on the composition of the primitive atmosphere. In order for substantial amounts of organic compounds to have been present on the prebiological Earth, certain conditions must have existed. There is a large body of literature on the prebiotic synthesis of organic compounds in various postulated atmospheres. In this mixture of abiotically synthesized organic compounds, the amino acids are of special interest since they are utilized by modern organisms to synthesize structural materials and a large array of catalytic peptides.

Characterization of Epithelial Progenitors in Normal Human Palatine Tonsils and Their HPV16 E6/E7-Induced Perturbation

PubMed Central

Kang, Sung Yoon Catherine; Kannan, Nagarajan; Zhang, Lewei; Martinez, Victor; Rosin, Miriam P.; Eaves, Connie J.

2015-01-01

Summary Human palatine tonsils are oropharyngeal lymphoid tissues containing multiple invaginations (crypts) in which the continuity of the outer surface epithelium is disrupted and the isolated epithelial cells intermingle with other cell types. We now show that primitive epithelial cells detectable in vitro in 2D colony assays and in a 3D culture system are CD44+NGFR+ and present in both surface and crypt regions. Transcriptome analysis indicated a high similarity between CD44+NGFR+ cells in both regions, although those isolated from the crypt contained a higher proportion of the most primitive (holo)clonogenic cells. Lentiviral transduction of CD44+NGFR+ cells from both regions with human papillomavirus 16-encoded E6/E7 prolonged their growth in 2D cultures and caused aberrant differentiation in 3D cultures. Our findings therefore reveal a shared, site-independent, hierarchical organization, differentiation potential, and transcriptional profile of normal human tonsillar epithelial progenitor cells. They also introduce a new model for investigating the mechanisms of their transformation. PMID:26527383

Differentiation of neural crest stem cells from nasal mucosa into motor neuron-like cells.

PubMed

Bagher, Zohreh; Kamrava, Seyed Kamran; Alizadeh, Rafieh; Farhadi, Mohammad; Absalan, Moloud; Falah, Masoumeh; Faghihi, Faezeh; Zare-Sadeghi, Arash; Komeili, Ali

2018-05-25

Cell transplantation is a potential therapeutic approach for repairing neuropathological and neurodegenerative disorders of central nervous system by replacing the degenerated cells with new ones. Among a variety of stem cell candidates to provide these new cells, olfactory ectomesenchymal stem cells (OE-MSCs) have attracted a great attention due to their neural crest origin, easy harvest, high proliferation, and autologous transplantation. Since there is no report on differentiation potential of these cells into motor neuron-like cells, we evaluated this potential using Real-time PCR, flowcytometry and immunocytochemistry after the treatment with differentiation cocktail containing retinoic acid and Sonic Hedgehog. Immunocytochemistry staining of the isolated OE-MSCs demonstrated their capability to express nestin and vimentin, as the two markers of primitive neuroectoderm. The motor neuron differentiation of OE-MSCs resulted in changing their morphology into bipolar cells with high expression of motor neuron markers of ChAT, Hb-9 and Islet-1 at the level of mRNA and protein. Consequently, we believe that the OE-MSCs have great potential to differentiate into motor neuron-like cells and can be an ideal stem cell source for the treatment of motor neuron-related disorders of central nervous system. Copyright © 2018 Elsevier B.V. All rights reserved.

HCN - A plausible source of purines, pyrimidines and amino acids on the primitive earth

NASA Technical Reports Server (NTRS)

Ferris, J.-P.; Joshi, P. C.; Edelson, E. H.; Lawless, J. G.

1978-01-01

Dilute (0.1 M) solutions of HCN condense to oligomers at pH 9.2, and hydrolysis of these oligomers yields 4,5-dihydroxypyrimidine, orotic acid, 5-hydroxyuracil, adenine, 4-aminoimidazole-5-carboxamide, and amino acids. It is suggested that the three main classes of nitrogen-containing biomolecules - purines, pyrimidines, and amino acids may have originated from HCN on the primitive earth. It is also suggested that the presence of orotic acid and 4-aminoimidazole-5-carboxamide might indicate that contemporary biosynthetic pathways for nucleotides evolved from the compounds released on hydrolysis of HCN oligomers.

Crystallization and diffraction analysis of [beta]-N-acetylhexosaminidase from Aspergillus oryzae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanek, Ondrej; Brynd, Jirí; Hofbauerová, Katerina

2012-05-08

Fungal {beta}-N-acetylhexosaminidases are enzymes that are used in the chemoenzymatic synthesis of biologically interesting oligosaccharides. The enzyme from Aspergillus oryzae was produced and purified from its natural source and crystallized using the hanging-drop vapor-diffusion method. Diffraction data from two crystal forms (primitive monoclinic and primitive tetragonal) were collected to resolutions of 3.2 and 2.4 {angstrom}, respectively. Electrophoretic and quantitative N-terminal protein-sequencing analyses confirmed that the crystals are formed by a complete biologically active enzyme consisting of a glycosylated catalytic unit and a noncovalently attached propeptide.

Teleost growth factor independence (gfi) genes differentially regulate successive waves of hematopoiesis.

PubMed

Cooney, Jeffrey D; Hildick-Smith, Gordon J; Shafizadeh, Ebrahim; McBride, Paul F; Carroll, Kelli J; Anderson, Heidi; Shaw, George C; Tamplin, Owen J; Branco, Diana S; Dalton, Arthur J; Shah, Dhvanit I; Wong, Clara; Gallagher, Patrick G; Zon, Leonard I; North, Trista E; Paw, Barry H

2013-01-15

Growth Factor Independence (Gfi) transcription factors play essential roles in hematopoiesis, differentially activating and repressing transcriptional programs required for hematopoietic stem/progenitor cell (HSPC) development and lineage specification. In mammals, Gfi1a regulates hematopoietic stem cells (HSC), myeloid and lymphoid populations, while its paralog, Gfi1b, regulates HSC, megakaryocyte and erythroid development. In zebrafish, gfi1aa is essential for primitive hematopoiesis; however, little is known about the role of gfi1aa in definitive hematopoiesis or about additional gfi factors in zebrafish. Here, we report the isolation and characterization of an additional hematopoietic gfi factor, gfi1b. We show that gfi1aa and gfi1b are expressed in the primitive and definitive sites of hematopoiesis in zebrafish. Our functional analyses demonstrate that gfi1aa and gfi1b have distinct roles in regulating primitive and definitive hematopoietic progenitors, respectively. Loss of gfi1aa silences markers of early primitive progenitors, scl and gata1. Conversely, loss of gfi1b silences runx-1, c-myb, ikaros and cd41, indicating that gfi1b is required for definitive hematopoiesis. We determine the epistatic relationships between the gfi factors and key hematopoietic transcription factors, demonstrating that gfi1aa and gfi1b join lmo2, scl, runx-1 and c-myb as critical regulators of teleost HSPC. Our studies establish a comparative paradigm for the regulation of hematopoietic lineages by gfi transcription factors. Copyright © 2012 Elsevier Inc. All rights reserved.

Identification of centromere regions in chromosomes of a unicellular red alga, Cyanidioschyzon merolae.

PubMed

Kanesaki, Yu; Imamura, Sousuke; Matsuzaki, Motomichi; Tanaka, Kan

2015-05-08

To investigate the evolution of centromere architecture in plant cells, it is important to identify centromere regions of primitive algae, such as Cyanidioschyzon merolae. In a previous genome project, in silico analysis predicted an AT-rich region in each chromosome as putative centromere regions. Here, we identified a centromere position in each chromosome by ChIP-on-chip analysis using an anti-CENP-A antibody. The identified centromeres were of the regional type, about 2-3 kb in length and contained no consensus or repeat elements. Centromeres in primitive eukaryotic plant cells may have originated from these regional type centromeres. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

On cat's eyes and multiple disjoint cells natural convection flow in tall tilted cavities

NASA Astrophysics Data System (ADS)

Báez, Elsa; Nicolás, Alfredo

2014-10-01

Natural convection fluid flow in air-filled tall tilted cavities is studied numerically with a direct projection method applied on the unsteady Boussinesq approximation in primitive variables. The study is focused on the so called cat's eyes and multiple disjoint cells as the aspect ratio A and the angle of inclination ϕ of the cavity vary. Results have already been reported with primitive and stream function-vorticity variables. The former are validated with the latter ones, which in turn were validated through mesh size and time-step independence studies. The new results complemented with the previous ones lead to find out the fluid motion and heat transfer invariant properties of this thermal phenomenon, which is the novelty here.

Human Induced Pluripotent Stem Cell-Derived Macrophages for Unraveling Human Macrophage Biology.

PubMed

Zhang, Hanrui; Reilly, Muredach P

2017-11-01

Despite a substantial appreciation for the critical role of macrophages in cardiometabolic diseases, understanding of human macrophage biology has been hampered by the lack of reliable and scalable models for cellular and genetic studies. Human induced pluripotent stem cell (iPSC)-derived macrophages (IPSDM), as an unlimited source of subject genotype-specific cells, will undoubtedly play an important role in advancing our understanding of the role of macrophages in human diseases. In this review, we summarize current literature in the differentiation and characterization of IPSDM at phenotypic, functional, and transcriptomic levels. We emphasize the progress in differentiating iPSC to tissue resident macrophages, and in understanding the ontogeny of in vitro differentiated IPSDM that resembles primitive hematopoiesis, rather than adult definitive hematopoiesis. We review the application of IPSDM in modeling both Mendelian genetic disorders and host-pathogen interactions. Finally, we highlighted the potential areas of research using IPSDM in functional validation of coronary artery disease loci in genome-wide association studies, functional genomic analyses, drug testing, and cell therapeutics in cardiovascular diseases. © 2017 American Heart Association, Inc.

Cellular reprogramming in skin cancer.

PubMed

Song, Ihn Young; Balmain, Allan

2015-06-01

Early primitive stem cells have long been viewed as the cancer cells of origin (tumor initiating target cells) due to their intrinsic features of self-renewal and longevity. However, emerging evidence suggests a surprising capacity for normal committed cells to function as reserve stem cells upon reprogramming as a consequence of tissue damage resulting in inflammation and wound healing. This results in an alternative concept positing that tumors may originate from differentiated cells that can re-acquire stem cell properties due to genetic or epigenetic reprogramming. It is likely that both models are correct, and that a continuum of potential cells of origin exists, ranging from early primitive stem cells to committed progenitor or even terminally differentiated cells. A combination of the nature of the target cell and the specific types of gene mutations introduced determine tumor cell lineage, as well as potential for malignant conversion. Evidence from mouse skin models of carcinogenesis suggests that initiated cells at different stages within a stem cell hierarchy have varying degrees of requirement for reprogramming (e.g. inflammation stimuli), depending on their degree of differentiation. This article will present evidence in favor of these concepts that has been developed from studies of several mouse models of skin carcinogenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stability of model membranes in extreme environments.

PubMed

Namani, Trishool; Deamer, David W

2008-08-01

The first forms of cellular life required a source of amphiphilic compounds capable of assembling into stable boundary structures. Membranes composed of fatty acids have been proposed as model systems of primitive membranes, but their bilayer structure is stable only within a narrow pH range and low ionic strength. They are particularly sensitive to aggregating effects of divalent cations (Mg+2, Ca+2, Fe+2) that would be present in Archaean sea water. Here we report that mixtures of alkyl amines and fatty acids form vesicles at strongly basic and acidic pH ranges which are resistant to the effects of divalent cations up to 0.1 M. Vesicles formed by mixtures of decylamine and decanoic acid (1:1 mole ratio) are relatively permeable to pyranine, a fluorescent anionic dye, but permeability could be reduced by adding 2 mol% of a polycyclic aromatic hydrocarbon such as pyrene. Permeability to the dye was also reduced by increasing the chain length of the amphiphiles. For instance, 1:1 mole ratio mixtures of dodecylamine and dodecanoic acid were able to retain pyranine dye during and following gel filtration. We conclude that primitive cell membranes were likely to be composed of mixtures of amphiphilic and hydrophobic molecules that manifested increased stability over pure fatty acid membranes.

Crystallization and preliminary X-ray analysis of PH1566, a putative ribosomal RNA-processing factor from the hyperthermophilic archaeon Pyrococcus horikoshii OT3

PubMed Central

Jia, Min Ze; Ohtsuka, Jun; Lee, Woo Cheol; Nagata, Koji; Tanokura, Masaru

2006-01-01

A putative ribosomal RNA-processing factor consisting of two KH domains from Pyrococcus horikoshii OT3 (PH1566; 25 kDa) was crystallized by the sitting-drop vapour-diffusion method using PEG 3000 as the precipitant. The crystals diffracted X-rays to beyond 2.0 Å resolution using a synchrotron-radiation source. The space group of the crystals was determined as primitive orthorhombic P212121, with unit-cell parameters a = 45.9, b = 47.4, c = 95.7 Å. The crystals contain one molecule in the asymmetric unit (V M = 2.5 Å3 Da−1) and have a solvent content of 50%. PMID:16511260

A recursive vesicle-based model protocell with a primitive model cell cycle

NASA Astrophysics Data System (ADS)

Kurihara, Kensuke; Okura, Yusaku; Matsuo, Muneyuki; Toyota, Taro; Suzuki, Kentaro; Sugawara, Tadashi

2015-09-01

Self-organized lipid structures (protocells) have been proposed as an intermediate between nonliving material and cellular life. Synthetic production of model protocells can demonstrate the potential processes by which living cells first arose. While we have previously described a giant vesicle (GV)-based model protocell in which amplification of DNA was linked to self-reproduction, the ability of a protocell to recursively self-proliferate for multiple generations has not been demonstrated. Here we show that newborn daughter GVs can be restored to the status of their parental GVs by pH-induced vesicular fusion of daughter GVs with conveyer GVs filled with depleted substrates. We describe a primitive model cell cycle comprising four discrete phases (ingestion, replication, maturity and division), each of which is selectively activated by a specific external stimulus. The production of recursive self-proliferating model protocells represents a step towards eventual production of model protocells that are able to mimic evolution.

Correct Patterning of the Primitive Streak Requires the Anterior Visceral Endoderm

PubMed Central

Stuckey, Daniel W.; Di Gregorio, Aida; Clements, Melanie; Rodriguez, Tristan A.

2011-01-01

Anterior-posterior axis specification in the mouse requires signalling from a specialised extra-embryonic tissue called the anterior visceral endoderm (AVE). AVE precursors are induced at the distal tip of the embryo and move to the prospective anterior. Embryological and genetic analysis has demonstrated that the AVE is required for anterior patterning and for correctly positioning the site of primitive streak formation by inhibiting Nodal activity. We have carried out a genetic ablation of the Hex-expressing cells of the AVE (Hex-AVE) by knocking the Diphtheria toxin subunit A into the Hex locus in an inducible manner. Using this model we have identified that, in addition to its requirement in the anterior of the embryo, the Hex-AVE sub-population has a novel role between 5.5 and 6.5dpc in patterning the primitive streak. Embryos lacking the Hex-AVE display delayed initiation of primitive streak formation and miss-patterning of the anterior primitive streak. We demonstrate that in the absence of the Hex-AVE the restriction of Bmp2 expression to the proximal visceral endoderm is also defective and expression of Wnt3 and Nodal is not correctly restricted to the posterior epiblast. These results, coupled with the observation that reducing Nodal signalling in Hex-AVE ablated embryos increases the frequency of phenotypes observed, suggests that these primitive streak patterning defects are due to defective Nodal signalling. Together, our experiments demonstrate that the AVE is not only required for anterior patterning, but also that specific sub-populations of this tissue are required to pattern the posterior of the embryo. PMID:21445260

THE CELLULAR ORIGIN OF HUMAN IMMUNOGLOBULINS (γ2, γ1M, γ1A)

PubMed Central

Mellors, Robert C.; Korngold, Leonhard

1963-01-01

A study was made of the cellular origin of human immunoglobulins (γ2, γ1M, γ1A). The results indicated that two closely related families of cells form immunoglobulins in human lymphoid tissue: germinal (reticular) centers and plasma cells. Thus their cellular origin in addition to their known antigenic relations further justifies placing the immunoglobulins in one family of proteins. Immunoglobulins were also formed to a small extent in primitive reticular cells which resembled those of germinal centers but were separated from them. Possibly such cells were undergoing transition to the much more numerous plasma cells with which they were commonly associated. The mantles of small lymphocytes which surrounded germinal centers did not contain detectable quantities of immunoglobulins. While in general only one type of immunoglobulin was present in an individual cell or germinal center, γ2- and γ1M-globulin were identified on occasion in the same plasma cell and germinal center. A peculiarity of the fetal thymus gland was the presence of immunoglobulin, mainly γ1M, in a small number of cells of small and intermediate size and primitive reticular appearance and in Hassall's corpuscles. PMID:14077999

Self-organization of neural tissue architectures from pluripotent stem cells.

PubMed

Karus, Michael; Blaess, Sandra; Brüstle, Oliver

2014-08-15

Despite being a subject of intensive research, the mechanisms underlying the formation of neural tissue architectures during development of the central nervous system remain largely enigmatic. So far, studies into neural pattern formation have been restricted mainly to animal experiments. With the advent of pluripotent stem cells it has become possible to explore early steps of nervous system development in vitro. These studies have unraveled a remarkable propensity of primitive neural cells to self-organize into primitive patterns such as neural tube-like rosettes in vitro. Data from more advanced 3D culture systems indicate that this intrinsic propensity for self-organization can even extend to the formation of complex architectures such as a multilayered cortical neuroepithelium or an entire optic cup. These novel experimental paradigms not only demonstrate the enormous self-organization capacity of neural stem cells, they also provide exciting prospects for studying the earliest steps of human neural tissue development and the pathogenesis of brain malformations in reductionist in vitro paradigms. © 2014 Wiley Periodicals, Inc.

A Quantitative Proteomic Analysis of Hemogenic Endothelium Reveals Differential Regulation of Hematopoiesis by SOX17

PubMed Central

Clarke, Raedun L.; Robitaille, Aaron M.; Moon, Randall T.; Keller, Gordon

2015-01-01

Summary The in vitro derivation of hematopoietic stem cells (HSCs) from pluripotent stem cells (PSCs) is complicated by the existence of multiple overlapping embryonic blood cell programs called primitive, erythromyeloid progenitor (EMP), and definitive. As HSCs are only generated during the definitive stage of hematopoiesis, deciphering the regulatory pathways that control the emergence of this program and identifying markers that distinguish it from the other programs are essential. To identify definitive specific pathways and marker sets, we used label-free proteomics to determine the proteome of embryo-derived and mouse embryonic stem cell-derived VE-CADHERIN+CD45− definitive hematopoietic progenitors. With this approach, we identified Stat1 as a marker that distinguishes the definitive erythroid lineage from the primitive- and EMP-derived lineages. Additionally, we provide evidence that the generation of the Stat1+ definitive lineage is dependent on Sox17. These findings establish an approach for monitoring the emergence of definitive hematopoiesis in the PSC differentiation cultures. PMID:26267830

Increasing Stem Cell Dose Promotes Posttransplant Immune Reconstitution.

PubMed

Xu, Ning; Shen, Sylvie; Dolnikov, Alla

2017-04-01

Umbilical cord blood (UCB) transplantation can provide a successful therapeutic option for patients that have no suitable related donor. UCB transplantation is often limited by the relatively small hematopoietic stem cell (HSC) numbers in UCB especially for adult recipients. Early neutrophil and platelet engraftment correlates with the stem cell numbers in UCB transplant. Compared to other HSC sources, immune reconstitution following UCB transplant is slower and complicated by increased frequency of opportunistic infections. The effect of HSC numbers in UCB transplant on immune reconstitution was not thoroughly examined. Using immunocompromised mice transplanted with purified UCB CD34+ stem cells, we have demonstrated that increasing the numbers of CD34+ cells in the transplant promotes hematopoietic and immune reconstitution. At early stages posttransplant, high stem cell dose generated relatively more B cells, while lower dose generated more myeloid and T cells. Thus, the size of the stem cell graft appears to modulate the differentiation potential of infused stem cells. In addition, increasing stem cell dose in the transplant improved CD8+ T cell development and delayed late memory T cell skewing in expense of naive T cells highlighting the importance of HSC dose to maintain the pool of naive T cells able to develop strong immune responses. Transplantation of ex vivo expanded CD34+ cells did not promote, but rather delayed immune reconstitution suggesting the loss of primitive lymphoid precursor cells during ex vivo expansion.

Congenital Ewing's Sarcoma/Peripheral Primitive Neuroectodermal Tumor: A Case Report and Review of the Literature.

PubMed

Jin, Shu-Guang; Jiang, Xiao-Ping; Zhong, Lin

2016-10-01

Ewing's sarcoma (EWS) and peripheral primitive neuroectodermal tumor (pPNET) are small round cell malignancies that develop in soft tissue and bone. They very rarely affect newborns. A diagnosis of EWS/pPNET depends mainly on immunohistochemistry and molecular/genetic assays. Since these tumors are highly aggressive, patient prognosis is typically very poor, and treatment remains a challenge. Here, we report a 13-day-old newborn diagnosed with congenital EWS/pPNET and describe its treatment. Copyright © 2014. Published by Elsevier B.V.

p28 in Treating Younger Patients With Recurrent or Progressive Central Nervous System Tumors

ClinicalTrials.gov

2017-08-03

Teratoid Tumor, Atypical; Choroid Plexus Neoplasms; Anaplastic Astrocytoma; Anaplastic Oligodendroglioma; Brainstem Tumors; Giant Cell Glioblastoma; Glioblastoma; Gliosarcoma; Medulloblastoma; Neuroectodermal Tumor, Primitive

Expression of hydroxyindole-O-methyltransferase enzyme in the human central nervous system and in pineal parenchymal cell tumors.

PubMed

Fukuda, Takahiro; Akiyama, Nobutake; Ikegami, Masahiro; Takahashi, Hitoshi; Sasaki, Atsushi; Oka, Hidehiro; Komori, Takashi; Tanaka, Yuko; Nakazato, Youichi; Akimoto, Jiro; Tanaka, Masahiko; Okada, Yoshikazu; Saito, Saburo

2010-05-01

Pineal parenchymal tumor (PPT) cells usually show immunoreactivity for synaptophysin, neuron-specific enolase, neurofilament protein, class III beta-tubulin, tau protein, PGP9.5, chromogranin, serotonin, retinal S-antigen, and rhodopsin, but these markers are not specific for PPTs. Melatonin is produced and secreted mainly bypineal parenchymal cells; hydroxyindole-O-methyltransferase (HIOMT) catalyzes the final reaction in melatonin biosynthesis. We hypothesized that HIOMT could serve as a tumor marker of PPTs, and we investigated HIOMT localization and HIOMT expression in samples of normal human tissue and in PPTs, primitive neuroectodermal tumors, and medulloblastomas. In normal tissue, HIOMT was expressed in retinal cells, pineal parenchymal cells, neurons of the Edinger-Westphal nucleus, microglia, macrophages, thyroid follicular epithelium, principal and oxyphil cells of parathyroid gland, adrenal cortical cells, hepatic parenchymal cells, renal tubule epithelium, and enteroendocrine cells of stomach and duodenum. The HIOMT was also expressed in all 46 PPTs studied. The proportions of HIOMT-immunoreactive cells successively decreased in the following tumors: pineocytoma, pineal parenchymal tumor of intermediate differentiation, and pineoblastoma. A few HIOMT-immunoreactive cells were observed in one of 6 primitive neuroectodermal tumors and 23 of 42 medulloblastomas. These results indicate that HIOMT immunohistochemistry may be useful for the diagnosis of PPTs and be a prognostic factor in PPTs.

Multipotent progenitor cells are present in human peripheral blood.

PubMed

Cesselli, Daniela; Beltrami, Antonio Paolo; Rigo, Silvia; Bergamin, Natascha; D'Aurizio, Federica; Verardo, Roberto; Piazza, Silvano; Klaric, Enio; Fanin, Renato; Toffoletto, Barbara; Marzinotto, Stefania; Mariuzzi, Laura; Finato, Nicoletta; Pandolfi, Maura; Leri, Annarosa; Schneider, Claudio; Beltrami, Carlo Alberto; Anversa, Piero

2009-05-22

To determine whether the peripheral blood in humans contains a population of multipotent progenitor cells (MPCs), products of leukapheresis were obtained from healthy donor volunteers following the administration of granulocyte colony-stimulating factor. Small clusters of adherent proliferating cells were collected, and these cells continued to divide up to 40 population doublings without reaching replicative senescence and growth arrest. MPCs were positive for the transcription factors Nanog, Oct3/4, Sox2, c-Myc, and Klf4 and expressed several antigens characteristic of mesenchymal stem cells. However, they were negative for markers of hematopoietic stem/progenitor cells and bone marrow cell lineages. MPCs had a cloning efficiency of approximately 3%, and following their expansion, retained a highly immature phenotype. Under permissive culture conditions, MPCs differentiated into neurons, glial cells, hepatocytes, cardiomyocytes, endothelial cells, and osteoblasts. Moreover, the gene expression profile of MPCs partially overlapped with that of neural and embryonic stem cells, further demonstrating their primitive, uncommitted phenotype. Following subcutaneous transplantation in nonimmunosuppressed mice, MPCs migrated to distant organs and integrated structurally and functionally within the new tissue, acquiring the identity of resident parenchymal cells. In conclusion, undifferentiated cells with properties of embryonic stem cells can be isolated and expanded from human peripheral blood after granulocyte colony-stimulating factor administration. This cell pool may constitute a unique source of autologous cells with critical clinical import.

Understanding Microbial Sensing in Inflammatory Bowel Disease Using Click Chemistry

DTIC Science & Technology

2017-10-01

pathogens and commensals. However, the technology available to track these molecules in host cells and tissues remains primitive. To address this...live, luminal bacteria into specific host intestinal immune cells and their subsequent degradation in host phagocytes. Notably, this approach also...click-chemistry, bacterial cell wall, bacterial outer membrane, peptidoglycan, lipopolysaccharide, endotoxin, capsular polysaccharide, inflammatory

Understanding Microbial Sensing in Inflammatory Bowel Disease Using Click Chemistry

DTIC Science & Technology

2017-10-01

both pathogens and commensals. However, the technology available to track these molecules in host cells and tissues remains primitive. To address this...from live, luminal bacteria into specific host intestinal immune cells and their subsequent degradation in host phagocytes. Notably, this approach...Bioorthogonal click-chemistry, bacterial cell wall, bacterial outer membrane, peptidoglycan, lipopolysaccharide, endotoxin, capsular polysaccharide

Human embryonic stem cell-derived neural crest cells capable of expressing markers of osteochondral or meningeal-choroid plexus differentiation.

PubMed

Sternberg, Hal; Jiang, Jianjie; Sim, Pamela; Kidd, Jennifer; Janus, Jeffrey; Rinon, Ariel; Edgar, Ron; Shitrit, Alina; Larocca, David; Chapman, Karen B; Binette, Francois; West, Michael D

2014-01-01

The transcriptome and fate potential of three diverse human embryonic stem cell-derived clonal embryonic progenitor cell lines with markers of cephalic neural crest are compared when differentiated in the presence of combinations of TGFβ3, BMP4, SCF and HyStem-C matrices. The cell lines E69 and T42 were compared with MEL2, using gene expression microarrays, immunocytochemistry and ELISA. In the undifferentiated progenitor state, each line displayed unique markers of cranial neural crest including TFAP2A and CD24; however, none expressed distal HOX genes including HOXA2 or HOXB2, or the mesenchymal stem cell marker CD74. The lines also showed diverse responses when differentiated in the presence of exogenous BMP4, BMP4 and TGFβ3, SCF, and SCF and TGFβ3. The clones E69 and T42 showed a profound capacity for expression of endochondral ossification markers when differentiated in the presence of BMP4 and TGFβ3, choroid plexus markers in the presence of BMP4 alone, and leptomeningeal markers when differentiated in SCF without TGFβ3. The clones E69 and T42 may represent a scalable source of primitive cranial neural crest cells useful in the study of cranial embryology, and potentially cell-based therapy.

Clonal analysis of lineage fate in native haematopoiesis.

PubMed

Rodriguez-Fraticelli, Alejo E; Wolock, Samuel L; Weinreb, Caleb S; Panero, Riccardo; Patel, Sachin H; Jankovic, Maja; Sun, Jianlong; Calogero, Raffaele A; Klein, Allon M; Camargo, Fernando D

2018-01-11

Haematopoiesis, the process of mature blood and immune cell production, is functionally organized as a hierarchy, with self-renewing haematopoietic stem cells and multipotent progenitor cells sitting at the very top. Multiple models have been proposed as to what the earliest lineage choices are in these primitive haematopoietic compartments, the cellular intermediates, and the resulting lineage trees that emerge from them. Given that the bulk of studies addressing lineage outcomes have been performed in the context of haematopoietic transplantation, current models of lineage branching are more likely to represent roadmaps of lineage potential than native fate. Here we use transposon tagging to clonally trace the fates of progenitors and stem cells in unperturbed haematopoiesis. Our results describe a distinct clonal roadmap in which the megakaryocyte lineage arises largely independently of other haematopoietic fates. Our data, combined with single-cell RNA sequencing, identify a functional hierarchy of unilineage- and oligolineage-producing clones within the multipotent progenitor population. Finally, our results demonstrate that traditionally defined long-term haematopoietic stem cells are a significant source of megakaryocyte-restricted progenitors, suggesting that the megakaryocyte lineage is the predominant native fate of long-term haematopoietic stem cells. Our study provides evidence for a substantially revised roadmap for unperturbed haematopoiesis, and highlights unique properties of multipotent progenitors and haematopoietic stem cells in situ.

Septic disruption of lactiferous ducts with heterogeneous carcinoma of the breast in a lactating woman.

PubMed

Naim, Mohammed; John, Vanesa T; Gaur, Kavita; Anees, Afzal

2010-08-06

This report documents the diagnostic histopathological features of heterogeneous breast carcinoma following sepsis and disruption of the lactiferous ducts in a lactating woman and discusses the pathogenesis. Sections from the nipple revealed disrupted collecting lactiferous ducts presenting with intraduct precarcinoma and carcinoma of the epidermoid type, and attached reparative sprouts lined by lactiferous cells. Breast lobules showed generalised benign adenotic change with various foci of carcinoma microscopically identifiable as intraduct primitive lactiferal ectodermal carcinoma, lactating carcinoma, primitive neuroendocrine carcinoma and myoepithelioid granulomatous carcinoma. The findings led to the conclusion that the lactiferous ducts are susceptible to sepsis and disruption, which may predispose a patient to breast carcinoma. The pattern of carcinoma suggested that lactiferous epithelial cells behaved colonially, with different metaplastic changes, precarcinoma and carcinoma.

Very small embryonic-like stem cells: implications in reproductive biology.

PubMed

Bhartiya, Deepa; Unni, Sreepoorna; Parte, Seema; Anand, Sandhya

2013-01-01

The most primitive germ cells in adult mammalian testis are the spermatogonial stem cells (SSCs) whereas primordial follicles (PFs) are considered the fundamental functional unit in ovary. However, this central dogma has recently been modified with the identification of a novel population of very small embryonic-like stem cells (VSELs) in the adult mammalian gonads. These stem cells are more primitive to SSCs and are also implicated during postnatal ovarian neo-oogenesis and primordial follicle assembly. VSELs are pluripotent in nature and characterized by nuclear Oct-4A, cell surface SSEA-4, and other pluripotent markers like Nanog, Sox2, and TERT. VSELs are considered to be the descendants of epiblast stem cells and possibly the primordial germ cells that persist into adulthood and undergo asymmetric cell division to replenish the gonadal germ cells throughout life. Elucidation of their role during infertility, endometrial repair, superovulation, and pathogenesis of various reproductive diseases like PCOS, endometriosis, cancer, and so on needs to be addressed. Hence, a detailed review of current understanding of VSEL biology is pertinent, which will hopefully open up new avenues for research to better understand various reproductive processes and cancers. It will also be relevant for future regenerative medicine, translational research, and clinical applications in human reproduction.

Stretching morphogenesis of the roof plate and formation of the central canal.

PubMed

Kondrychyn, Igor; Teh, Cathleen; Sin, Melvin; Korzh, Vladimir

2013-01-01

Neurulation is driven by apical constriction of actomyosin cytoskeleton resulting in conversion of the primitive lumen into the central canal in a mechanism driven by F-actin constriction, cell overcrowding and buildup of axonal tracts. The roof plate of the neural tube acts as the dorsal morphogenetic center and boundary preventing midline crossing by neural cells and axons. The roof plate zebrafish transgenics expressing cytosolic GFP were used to study and describe development of this structure in vivo for a first time ever. The conversion of the primitive lumen into the central canal causes significant morphogenetic changes of neuroepithelial cells in the dorsal neural tube. We demonstrated that the roof plate cells stretch along the D-V axis in parallel with conversion of the primitive lumen into central canal and its ventral displacement. Importantly, the stretching of the roof plate is well-coordinated along the whole spinal cord and the roof plate cells extend 3× in length to cover 2/3 of the neural tube diameter. This process involves the visco-elastic extension of the roof place cytoskeleton and depends on activity of Zic6 and the Rho-associated kinase (Rock). In contrast, stretching of the floor plate is much less extensive. The extension of the roof plate requires its attachment to the apical complex of proteins at the surface of the central canal, which depends on activity of Zic6 and Rock. The D-V extension of the roof plate may change a range and distribution of morphogens it produces. The resistance of the roof plate cytoskeleton attenuates ventral displacement of the central canal in illustration of the novel mechanical role of the roof plate during development of the body axis.

Stretching Morphogenesis of the Roof Plate and Formation of the Central Canal

PubMed Central

Kondrychyn, Igor; Teh, Cathleen; Sin, Melvin; Korzh, Vladimir

2013-01-01

Background Neurulation is driven by apical constriction of actomyosin cytoskeleton resulting in conversion of the primitive lumen into the central canal in a mechanism driven by F-actin constriction, cell overcrowding and buildup of axonal tracts. The roof plate of the neural tube acts as the dorsal morphogenetic center and boundary preventing midline crossing by neural cells and axons. Methodology/Principal Findings The roof plate zebrafish transgenics expressing cytosolic GFP were used to study and describe development of this structure in vivo for a first time ever. The conversion of the primitive lumen into the central canal causes significant morphogenetic changes of neuroepithelial cells in the dorsal neural tube. We demonstrated that the roof plate cells stretch along the D–V axis in parallel with conversion of the primitive lumen into central canal and its ventral displacement. Importantly, the stretching of the roof plate is well-coordinated along the whole spinal cord and the roof plate cells extend 3× in length to cover 2/3 of the neural tube diameter. This process involves the visco-elastic extension of the roof place cytoskeleton and depends on activity of Zic6 and the Rho-associated kinase (Rock). In contrast, stretching of the floor plate is much less extensive. Conclusions/Significance The extension of the roof plate requires its attachment to the apical complex of proteins at the surface of the central canal, which depends on activity of Zic6 and Rock. The D–V extension of the roof plate may change a range and distribution of morphogens it produces. The resistance of the roof plate cytoskeleton attenuates ventral displacement of the central canal in illustration of the novel mechanical role of the roof plate during development of the body axis. PMID:23409159

Contamination of the asteroid belt by primordial trans-Neptunian objects.

PubMed

Levison, Harold F; Bottke, William F; Gounelle, Matthieu; Morbidelli, Alessandro; Nesvorný, David; Tsiganis, Kleomenis

2009-07-16

The main asteroid belt, which inhabits a relatively narrow annulus approximately 2.1-3.3 au from the Sun, contains a surprising diversity of objects ranging from primitive ice-rock mixtures to igneous rocks. The standard model used to explain this assumes that most asteroids formed in situ from a primordial disk that experienced radical chemical changes within this zone. Here we show that the violent dynamical evolution of the giant-planet orbits required by the so-called Nice model leads to the insertion of primitive trans-Neptunian objects into the outer belt. This result implies that the observed diversity of the asteroid belt is not a direct reflection of the intrinsic compositional variation of the proto-planetary disk. The dark captured bodies, composed of organic-rich materials, would have been more susceptible to collisional evolution than typical main-belt asteroids. Their weak nature makes them a prodigious source of micrometeorites-sufficient to explain why most are primitive in composition and are isotopically different from most macroscopic meteorites.

Low-3He/4He sublithospheric mantle source for the most magnesian magmas of the Karoo large igneous province

NASA Astrophysics Data System (ADS)

Heinonen, Jussi S.; Kurz, Mark D.

2015-09-01

The massive outpourings of Karoo and Ferrar continental flood basalts (CFBs) ∼180 Ma ago mark the initial Jurassic rifting stages of the Gondwana supercontinent. The origin and sources of these eruptions have been debated for decades, largely due to difficulties in defining their parental melt and mantle source characteristics. Recent findings of Fe- and Mg-rich dikes (depleted ferropicrite suite) from Vestfjella, western Dronning Maud Land, Antarctica, have shed light on the composition of the deep sub-Gondwanan mantle: these magmas have been connected to upper mantle sources presently sampled by the Southwest Indian Ocean mid-ocean ridge basalts (SWIR MORBs) or to high 3He/4He plume-entrained non-chondritic primitive mantle sources formed early in Earth's history. In an attempt to determine their He isotopic composition and relative contributions from magmatic, cosmogenic, and radiogenic He sources, we performed in-vacuo stepwise crushing and melting analyses of olivine mineral separates, some of which were abraded to remove the outer layer of the grains. The best estimate for the mantle isotopic composition is given by a sample with the highest amount of He released (>50%) during the first crushing step of an abraded coarse fraction. It has a 3He/4He of 7.03 ± 0.23 (2σ) times the atmospheric ratio (Ra), which is indistinguishable from those measured from SWIR MORBs (6.3-7.3 Ra; source 3He/4He ∼6.4-7.6 Ra at 180 Ma) and notably lower than in the most primitive lavas from the North Atlantic Igneous Province (up to 50 Ra), considered to represent the epitome magmas from non-chondritic primitive mantle sources. Previously published trace element and isotopic (Sr, Nd, and Pb) compositions do not suggest a direct genetic link to any modern hotspot of Indian or southern Atlantic Oceans. Although influence of a mantle plume cannot be ruled out, the high magma temperatures and SWIR MORB-like geochemistry of the suite are best explained by supercontinent insulation of a precursory Indian Ocean upper mantle source. Such a model is also supported by the majority of the recent studies on the structure, geochronology, and petrology of the Karoo CFBs.

Chemotaxis of primitive hematopoietic cells in response to stromal cell–derived factor-1

PubMed Central

Jo, Deog-Yeon; Rafii, Shahin; Hamada, Tsuneyoshi; Moore, Malcolm A.S.

2000-01-01

Stromal cell–derived factor-1 (SDF-1) provides a potent chemotactic stimulus for CD34+ hematopoietic cells. We cultured mobilized peripheral blood (PB) and umbilical cord blood (CB) for up to 5 weeks and examined the migratory activity of cobblestone area–forming cells (CAFCs) and long-term culture–initiating cells (LTC-ICs) in a transwell assay. In this system, SDF-1 or MS-5 marrow stromal cells placed in the lower chamber induced transmembrane and transendothelial migration by 2- and 5-week-old CAFCs and LTC-ICs in 3 hours. Transmigration was blocked by preincubation of input CD34+ cells with antibody to CXCR4. Transendothelial migration of CB CAFCs and LTC-ICs was higher than that of PB. We expanded CD34+ cells from CB in serum-free medium with thrombopoietin, flk-2 ligand, and c-kit ligand, with or without IL-3 and found that CAFCs cultured in the absence of IL-3 had a chemotactic response equivalent to noncultured cells, even after 5 weeks. However, addition of IL-3 to the culture reduced this response by 20–50%. These data indicate that SDF-1 induces chemotaxis of primitive hematopoietic cells signaling through CXCR4 and that the chemoattraction could be downmodulated by culture ex vivo. PMID:10619866

The biological significance of cancer: mitochondria as a cause of cancer and the inhibition of glycolysis with citrate as a cancer treatment.

PubMed

Halabe Bucay, Alberto

2007-01-01

In this article, I present the hypothesis that cancer presents due to the domination of the cell by mitochondria, which, from an evolution viewpoint, appeared in multi-cellular living being with the incorporation of a bacteria into a primitive cell, the bacteria sustained itself as mitochondria and these conserved their identity and bacterial characteristics, based on this, the hypothesis is suggested of the biological competition between the cell and the mitochondria; the mitochondria, on establishing itself as an independent entity within the cell, created the need to permanently remain in the cytoplasm of the cell, thus, from an energy viewpoint, when a cell becomes malignant, the mitochondria are the sole beneficiaries, as there is an ideal environment at the cellular level for the mitochondria to sustain their functions, and from this hypothesis, the treatment for fighting cancer consists of inhibiting glycolysis, being the principal source of energy for the mitochondria, this is achieved by administering citrate to cancer patients, as the citrate inhibits the phosphofructokinase enzyme, the pyruvate dehydrogenase complex and the succinate dehydrogenase enzyme of Krebs cycle, thus, the mitochondria will be forced to limit their metabolism and, secondarily, will lower the reproduction capacity of the cell in general.

Ex-vivo expanded umbilical cord blood stem cells retain capacity for myocardial regeneration.

PubMed

Schlechta, Bernhard; Wiedemann, Dominik; Kittinger, Clemens; Jandrositz, Anita; Bonaros, Nikolaos E; Huber, Johannes C; Preisegger, Karl-Heinz; Kocher, Alfred A

2010-01-01

Umbilical cord blood (UCB) is a source of human hematopoietic precursor cells (HPCs), a stem cell (SC) type that has been used in several trials for myocardial repair. A certain minimal number of cells is required for measurable regeneration and a major challenge of SC-based regenerative therapy constitutes ex-vivo expansion of the primitive cell compartment. The aim of this study was to investigate the ex-vivo expansion potential of UCB-derived HPCs and the ability of these expanded cells to migrate to the site of damage and improve ventricular function in a rodent model of myocardial infarction (MI). UCB-derived HPCs, defined by coexpression of CD133 and CD34, were expanded using various cytokine combinations. MI was induced by left anterior descending artery ligation in nude rats. Cells were injected intravenously 2 days after infarction. The combination of SC factor, thrombopoietin, flt3-ligand and interleukin-6 was found to be the most effective for inducing proliferation of HPCs. The migratory capacity of expanded HPCs was similar to that of non-expanded HPCs and improvement of ejection fraction was significant in both groups, with a relative increase of >60%. UCB-derived HPCs can be reproducibly expanded ex-vivo and retain their potential to improve cardiac function post-MI. (Circ J 2010; 74: 188 - 194).

Structure and function of primitive immunoglobulin superfamily neural cell adhesion molecules: a lesson from studies on planarian.

PubMed

Fusaoka, Eri; Inoue, Takeshi; Mineta, Katsuhiko; Agata, Kiyokazu; Takeuchi, Kosei

2006-05-01

Precise wiring and proper remodeling of the neural network are essential for its normal function. The freshwater planarian is an attractive animal in which to study the formation and maintenance of the neural network due to its high regenerative capability and developmental plasticity. Although a recent study revealed that homologs of netrin and its receptors are required for regeneration and maintenance of the planarian central nervous system (CNS), the roles of cell adhesion in the formation and maintenance of the planarian neural network remain poorly understood. In the present study, we found primitive immunoglobulin superfamily cell adhesion molecules (IgCAMs) in a planarian that are homologous to vertebrate neural IgCAMs. We identified planarian orthologs of NCAM, L1CAM, contactin and DSCAM, and designated them DjCAM, DjLCAM, DjCTCAM and DjDSCAM, respectively. We further confirmed that they function as cell adhesion molecules using cell aggregation assays. DjCAM and DjDSCAM were found to be differentially expressed in the CNS. Functional analyses using RNA interference revealed that DjCAM is partly involved in axon formation, and that DjDSCAM plays crucial roles in neuronal cell migration, axon outgrowth, fasciculation and projection.

Acute erythremic myelosis (true erythroleukaemia): a variant of AML FAB-M6.

PubMed

Hasserjian, R P; Howard, J; Wood, A; Henry, K; Bain, B

2001-03-01

Classic erythroleukaemia (acute myeloid leukaemia M6, or M6 AML) is defined as an excess of myeloblasts in an erythroid predominant background. Leukaemia variants in which the primitive blast cells are demonstrably erythroid are extremely rare and poorly characterised. Variably referred to as "true erythroleukaemia" or "acute erythremic myelosis", they are often included within the M6 AML category even though they do not meet strict criteria for this type of AML. Two cases of acute erythroid neoplasia are presented with clinical, morphological, immunophenotypic, and cytogenetic analysis. Both patients presented with profound anaemia, one in a setting of long standing myelodysplasia. Bone marrow examination revealed a predominant population of highly dysplastic erythroid cells in both cases. In one case, the liver was infiltrated by neoplastic erythroid cells. Both patients died within four months of diagnosis. This report illustrates that cases of acute leukaemia occur in which the dominant neoplastic cell is a primitive erythroid cell without an accompanying increase in myeloblasts. This does not preclude the neoplastic clone originating in a multipotent haemopoietic stem cell, as suggested by cases arising in patients with myelodysplasia. Acute erythremic myelosis should be recognised as a distinct variant of M6 AML.

Downstream targets of HOXB4 in a cell line model of primitive hematopoietic progenitor cells.

PubMed

Lee, Han M; Zhang, Hui; Schulz, Vincent; Tuck, David P; Forget, Bernard G

2010-08-05

Enforced expression of the homeobox transcription factor HOXB4 has been shown to enhance hematopoietic stem cell self-renewal and expansion ex vivo and in vivo. To investigate the downstream targets of HOXB4 in hematopoietic progenitor cells, HOXB4 was constitutively overexpressed in the primitive hematopoietic progenitor cell line EML. Two genome-wide analytical techniques were used: RNA expression profiling using microarrays and chromatin immunoprecipitation (ChIP)-chip. RNA expression profiling revealed that 465 gene transcripts were differentially expressed in KLS (c-Kit(+), Lin(-), Sca-1(+))-EML cells that overexpressed HOXB4 (KLS-EML-HOXB4) compared with control KLS-EML cells that were transduced with vector alone. In particular, erythroid-specific gene transcripts were observed to be highly down-regulated in KLS-EML-HOXB4 cells. ChIP-chip analysis revealed that the promoter region for 1910 genes, such as CD34, Sox4, and B220, were occupied by HOXB4 in KLS-EML-HOXB4 cells. Side-by-side comparison of the ChIP-chip and RNA expression profiling datasets provided correlative information and identified Gp49a and Laptm4b as candidate "stemness-related" genes. Both genes were highly ranked in both dataset lists and have been previously shown to be preferentially expressed in hematopoietic stem cells and down-regulated in mature hematopoietic cells, thus making them attractive candidates for future functional studies in hematopoietic cells.

From catʼs eyes to multiple disjoint natural convection flow in tall tilted cavities: A direct primitive variables approach

NASA Astrophysics Data System (ADS)

Báez, Elsa; Nicolás, Alfredo

2013-11-01

Natural convection fluid flow in air-filled tall tilted cavities is studied numerically with a new direct projection method on the Boussinesq approximation in primitive variables. The study deals with “cat's eyes” instabilities and multiple disjoint cells as the aspect ratio A and the angle of inclination ϕ of the cavity vary. The flows are validated with those reported before using the stream function-vorticity variables. New cases, A=12 and 20 varying ϕ, lead to get more insight on the physical phenomenon.

Cell fate regulation in early mammalian development

NASA Astrophysics Data System (ADS)

Oron, Efrat; Ivanova, Natalia

2012-08-01

Preimplantation development in mammals encompasses a period from fertilization to implantation and results in formation of a blastocyst composed of three distinct cell lineages: epiblast, trophectoderm and primitive endoderm. The epiblast gives rise to the organism, while the trophectoderm and the primitive endoderm contribute to extraembryonic tissues that support embryo development after implantation. In many vertebrates, such as frog or fish, maternally supplied lineage determinants are partitioned within the egg. Cell cleavage that follows fertilization results in polarization of these factors between the individual blastomeres, which become restricted in their developmental fate. In contrast, the mouse oocyte and zygote lack clear polarity and, until the eight-cell stage, individual blastomeres retain the potential to form all lineages. How are cell lineages specified in the absence of a maternally supplied blueprint? This is a fundamental question in the field of developmental biology. The answer to this question lies in understanding the cell-cell interactions and gene networks involved in embryonic development prior to implantation and using this knowledge to create testable models of the developmental processes that govern cell fates. We provide an overview of classic and contemporary models of early lineage development in the mouse and discuss the emerging body of work that highlights similarities and differences between blastocyst development in the mouse and other mammalian species.

Vismodegib and Gamma-Secretase/Notch Signalling Pathway Inhibitor RO4929097 in Treating Patients With Advanced or Metastatic Sarcoma

ClinicalTrials.gov

2016-06-09

Adult Alveolar Soft Part Sarcoma; Adult Angiosarcoma; Adult Desmoplastic Small Round Cell Tumor; Adult Epithelioid Hemangioendothelioma; Adult Epithelioid Sarcoma; Adult Extraskeletal Myxoid Chondrosarcoma; Adult Extraskeletal Osteosarcoma; Adult Fibrosarcoma; Adult Leiomyosarcoma; Adult Liposarcoma; Adult Malignant Mesenchymoma; Adult Malignant Peripheral Nerve Sheath Tumor; Adult Rhabdomyosarcoma; Adult Synovial Sarcoma; Adult Unclassified Pleomorphic Sarcoma; Chondrosarcoma; Clear Cell Sarcoma of the Kidney; Conjunctival Kaposi Sarcoma; Dermatofibrosarcoma Protuberans; Gastrointestinal Stromal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Ovarian Sarcoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Adult Unclassified Pleomorphic Sarcoma of Bone; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Kaposi Sarcoma; Recurrent Osteosarcoma; Recurrent Uterine Corpus Sarcoma; Small Intestine Leiomyosarcoma; Stage III Adult Soft Tissue Sarcoma; Stage III Uterine Sarcoma; Stage IV Adult Soft Tissue Sarcoma; Stage IV Uterine Sarcoma; Unclassified Pleomorphic Sarcoma of Bone

Prolonged Growth Hormone/Insulin/Insulin-like Growth Factor Nutrient Response Signaling Pathway as a Silent Killer of Stem Cells and a Culprit in Aging.

PubMed

Ratajczak, Mariusz Z; Bartke, Andrzej; Darzynkiewicz, Zbigniew

2017-08-01

The dream of slowing down the aging process has always inspired mankind. Since stem cells are responsible for tissue and organ rejuvenation, it is logical that we should search for encoded mechanisms affecting life span in these cells. However, in adult life the hierarchy within the stem cell compartment is still not very well defined, and evidence has accumulated that adult tissues contain rare stem cells that possess a broad trans-germ layer differentiation potential. These most-primitive stem cells-those endowed with pluripotent or multipotent differentiation ability and that give rise to other cells more restricted in differentiation, known as tissue-committed stem cells (TCSCs) - are of particular interest. In this review we present the concept supported by accumulating evidence that a population of so-called very small embryonic-like stem cells (VSELs) residing in adult tissues positively impacts the overall survival of mammals, including humans. These unique cells are prevented in vertebrates from premature depletion by decreased sensitivity to growth hormone (GH), insulin (INS), and insulin-like growth factor (IGF) signaling, due to epigenetic changes in paternally imprinted genes that regulate their resistance to these factors. In this context, we can envision nutrient response GH/INS/IGF signaling pathway as a lethal factor for these most primitive stem cells and an important culprit in aging.

Resolving early mesoderm diversification through single-cell expression profiling.

PubMed

Scialdone, Antonio; Tanaka, Yosuke; Jawaid, Wajid; Moignard, Victoria; Wilson, Nicola K; Macaulay, Iain C; Marioni, John C; Göttgens, Berthold

2016-07-14

In mammals, specification of the three major germ layers occurs during gastrulation, when cells ingressing through the primitive streak differentiate into the precursor cells of major organ systems. However, the molecular mechanisms underlying this process remain unclear, as numbers of gastrulating cells are very limited. In the mouse embryo at embryonic day 6.5, cells located at the junction between the extra-embryonic region and the epiblast on the posterior side of the embryo undergo an epithelial-to-mesenchymal transition and ingress through the primitive streak. Subsequently, cells migrate, either surrounding the prospective ectoderm contributing to the embryo proper, or into the extra-embryonic region to form the yolk sac, umbilical cord and placenta. Fate mapping has shown that mature tissues such as blood and heart originate from specific regions of the pre-gastrula epiblast, but the plasticity of cells within the embryo and the function of key cell-type-specific transcription factors remain unclear. Here we analyse 1,205 cells from the epiblast and nascent Flk1(+) mesoderm of gastrulating mouse embryos using single-cell RNA sequencing, representing the first transcriptome-wide in vivo view of early mesoderm formation during mammalian gastrulation. Additionally, using knockout mice, we study the function of Tal1, a key haematopoietic transcription factor, and demonstrate, contrary to previous studies performed using retrospective assays, that Tal1 knockout does not immediately bias precursor cells towards a cardiac fate.

Peripheral primitive neuroectodermal tumor of the vulva: report of a case with imprint cytology.

PubMed

Takeshima, N; Tabata, T; Nishida, H; Furuta, N; Tsuzuku, M; Hirai, Y; Hasumi, K

2001-01-01

Peripheral primitive neuroectodermal tumor (PNET) of the vulva is an extremely rare disease, and, to our knowledge, only two cases have been previously reported. A 45-year-old woman presented with a mass in the right labium major. Three years after removal of the tumor, she noticed a new lesion in the same place and underwent a partial vulvectomy. The imprint cytology of the recurrent tumor showed a monomorphic appearance, composed of small round cells with scant cytoplasm against a hemorrhagic background. These tumor cells were loosely connective, but rosettelike structures were observed focally. On pathologic examination, the neoplasm was composed of small round tumor cells showing sinusoidal, diffuse or micropapillary growth. Immunohistochemically, the neoplastic cells stained positively for neuron-specific enolase, vimentin and HBA 71 and negatively for cytokeratin, HBA 45 and muscle-specific actin. The morphologic characteristics of the disease were well expressed in the imprint cytology, and this influenced the selection of immunohistochemical studies. Cytologic examination for vulvar tumors, even imprint cytology, can be a useful tool in obtaining an accurate pathologic diagnosis of a rare disease, such as peripheral PNET.

A recursive vesicle-based model protocell with a primitive model cell cycle

PubMed Central

Kurihara, Kensuke; Okura, Yusaku; Matsuo, Muneyuki; Toyota, Taro; Suzuki, Kentaro; Sugawara, Tadashi

2015-01-01

Self-organized lipid structures (protocells) have been proposed as an intermediate between nonliving material and cellular life. Synthetic production of model protocells can demonstrate the potential processes by which living cells first arose. While we have previously described a giant vesicle (GV)-based model protocell in which amplification of DNA was linked to self-reproduction, the ability of a protocell to recursively self-proliferate for multiple generations has not been demonstrated. Here we show that newborn daughter GVs can be restored to the status of their parental GVs by pH-induced vesicular fusion of daughter GVs with conveyer GVs filled with depleted substrates. We describe a primitive model cell cycle comprising four discrete phases (ingestion, replication, maturity and division), each of which is selectively activated by a specific external stimulus. The production of recursive self-proliferating model protocells represents a step towards eventual production of model protocells that are able to mimic evolution. PMID:26418735

The role of Late Veneer impacts in the evolution of Venus

NASA Astrophysics Data System (ADS)

Gillmann, C.; Golabek, G.; Tackley, P.; Raymond, S.

2017-09-01

We study how different mechanisms contribute to changes in long term evolution. In particular, the primitive history (the first Gy) of terrestrial planets is heavily influenced by collisions. We investigate how the coupled evolution of Venus' atmosphere and mantle is modified by those impacts. We focus on volatile fluxes: atmospheric escape and mantle degassing. We observe that large impacts are unlikely to erode the atmosphere significantly. They are, on the contrary, an important source of volatiles for the primitive planet. Collisions also generate a lot of melting and rapidly dries the mantle through degassing. Without recycling of volatiles into the mantle (like in plate tectonics regime), the mantle is efficiently depleted.

Energy yields in the prebiotic synthesis of hydrogen cyanide and formaldehyde

NASA Technical Reports Server (NTRS)

Stribling, R.; Miller, S. L.

1986-01-01

Prebiotic experiments are usually reported in terms of carbon yields, i.e., the yield of product based on the total carbon in the system. These experiments usually involve a large input of energy and are designed to maximize the yields of product. However, large inputs of energy result in multiple activation of the reactants and products. A more realistic prebiotic experiment is to remove the products of the activation step so they are not exposed a second time to the energy source. This is equivalent to transporting the products synthesized in the primitive atmosphere to the ocean, and thereby protecting them from destruction by atmospheric energy sources. Experiments of this type, using lower inputs of energy, give energy yields (moles of products/joule) which can be used to estimate the relative importance of the different energy sources on the primitive earth. Simulated prebiotic atmospheres containing either CH4, CO or CO2 with N2, H2O and variable amounts of H2 were subjected to a high frequency Tesla coil. Samples of the aqueous phase were taken at various time intervals from 1 hr to 7 days, and the energy yields were obtained by extrapolation to zero time. The samples were analyzed for HCN with the cyanide electrode and for H2CO by chromotropic acid. The spark energy was estimated by calorimetry. The temperature rise in an insulated discharge flask was compared with the temperature rise from a resistance heater in the same flask. These results will be compared with calculated production rates of HCN and H2CO from lightning and a number of photochemical processes on the primitive Earth.

Amniotic fluid stem cells prevent follicle atresia and rescue fertility of mice with premature ovarian failure induced by chemotherapy.

PubMed

Xiao, Guan-Yu; Liu, I-Hsuan; Cheng, Chun-Chun; Chang, Chia-Chun; Lee, Yen-Hua; Cheng, Winston Teng-Kuei; Wu, Shinn-Chih

2014-01-01

Chemotherapy used to treat cancer may cause irreversible premature ovarian failure (POF). Of late, amniotic fluid stem cells (AFSCs) provide a novel source for regenerative medicine because of their primitive stage, low immunogenicity, and easy accessibility. In this study, we isolated AFSCs from transgenic mice that ubiquitously express enhanced green fluorescence protein (EGFP). These AFSCs exhibited morphologies, immunophenotypes, and mesoderm trilineage differentiation potentials similar to mesenchymal stem cells (MSCs). Further, AFSCs proliferated faster than MSCs and expressed OCT4, a marker for pluripotency. To investigate their potential in recovering fertility in POF model, AFSCs were transplanted into the ovaries of mice with POF six weeks post induction using chemotherapeutic drugs, busulfan and cyclophosphamide. AFSCs could rescue the reproductive ability of mice with POF by preventing follicle atresia and sustaining the healthy follicles. Notably, the transplanted AFSCs did not differentiate into granulosa and germline cells in vivo. After one month, the decreased numbers of transplanted AFSCs accompanied with the reduced beneficial effects indicated that the therapeutic efficacy were directly from AFSCs. These findings demonstrated the therapeutic effects of AFSCs and suggested the promise of AFSCs for treating infertility and POF caused by chemotherapy.

In Pursuit of Prostate Cancer Stem Cells

DTIC Science & Technology

2007-01-01

cells with different tumorigenicities and primitiveness in human PCa xenografts and cell lines. In this study, we seek to reevaluate the relevancy...us prostatospheres and establish primary xenografts in order to carry out our proposed experiments. Preliminary in vitro experiments indicate that...LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a. REPORT U b. ABSTRACT U c. THIS PAGE U UU 31

In vitro long-term culture of human primitive hematopoietic cells supported by murine stromal cell line MS-5.

PubMed

Nishi, N; Ishikawa, R; Inoue, H; Nishikawa, M; Yoneya, T; Kakeda, M; Tsumura, H; Ohashi, H; Mori, K J

1997-04-01

When Lin-CD34+CD38- cells from normal human cord blood were cocultured with MS-5, colony forming cells were maintained for over 8 weeks. Prevention of contact between MS-5 and Lin-CD34+CD38- cells by using a membrane filter was negligible for this activity, indicating that the activity of MS-5 on human primitive hematopoietic cells may be due to soluble factor(s) secreted from MS-5. We tried to purify this activity by a [3H]TdR incorporation assay. The activity was found in 150 kD fraction and was neutralized with anti-mSCF (stem cell factor) antibody. Another 20-30 kD fraction synergized with mSCF to stimulate the growth of Lin-CD34+CD38- cells but failed alone. This fraction supported the growth of the G-CSF (granulocyte-colony stimulating factor)-dependent cell line FD/GR3, FDC-P2 transfected with mG-CSF receptor cDNA. This synergy was canceled in the presence of soluble mG-CSF receptor. Addition of anti-mSCF antibody and soluble mG-CSF receptor to the culture completely abrogated the activity of MS-5-culture supernatant. These results indicate the activity of MS-5 on Lin-CD34+CD38- cells is due to synergistic effect of mSCF and mG-CSF.

Optimizing homeostatic cell renewal in hierarchical tissues

PubMed Central

Fider, Nicole A.

2018-01-01

In order to maintain homeostasis, mature cells removed from the top compartment of hierarchical tissues have to be replenished by means of differentiation and self-renewal events happening in the more primitive compartments. As each cell division is associated with a risk of mutation, cell division patterns have to be optimized, in order to minimize or delay the risk of malignancy generation. Here we study this optimization problem, focusing on the role of division tree length, that is, the number of layers of cells activated in response to the loss of terminally differentiated cells, which is related to the balance between differentiation and self-renewal events in the compartments. Using both analytical methods and stochastic simulations in a metapopulation-style model, we find that shorter division trees are advantageous if the objective is to minimize the total number of one-hit mutants in the cell population. Longer division trees on the other hand minimize the accumulation of two-hit mutants, which is a more likely evolutionary goal given the key role played by tumor suppressor genes in cancer initiation. While division tree length is the most important property determining mutant accumulation, we also find that increasing the size of primitive compartments helps to delay two-hit mutant generation. PMID:29447149

Identification of progenitor cancer stem cell in lentigo maligna melanoma.

PubMed

Bongiorno, M R; Doukaki, S; Malleo, F; Aricò, M

2008-07-01

The potential role of stem cells in neoplasia has aroused considerable interest over the past few years. A number of known biologic characteristics of melanomas support the theory that they may originate in a mutated stem cell. Melanocytic stem cell markers have been described recently. Moreover, the CD133 cells that show surface markers for CD34 are stem cells primitive. These stem cells are capable of differentiating into neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. The identification of cancer stem/initiating cells with a crucial role in tumor formation may open up new pharmacologic perspectives. The purpose of this study is to detect the expression of CD133 and CD34, two putative markers of cancer stem cells in the lentigo maligna melanoma. Thirty cases of lentigo maligna melanoma were analyzed using indirect immunohistochemical staining. The vast majority of the samples analyzed showed the presence of rare cells, which were clearly positive for CD133 and CD34. Strong CD133 and CD34 staining was found in the outer root sheath of the mid-lower hair follicles, intermixed with atypical melanocytes extending along layers of the hair follicles. A number of these staminal cells were adjacent and intermixed with melanoma cells. This study supports the stem cell origin of this tumor and suggests that the precursor of the melanoma in question is a stem-like cell rather than the primitive melanoblast committed to be exclusively involved in melanocytic differentiation.

Diapirism and the origin of high TiO2 mare glasses

NASA Technical Reports Server (NTRS)

Hess, Paul C.

1991-01-01

High TiO2 mare picritic glasses are derived from cumulate source regions that are only modestly endowed with ilmenite-enriched crystallization products. These sources are mobilized by the heat derived from the primitive interior and evolve into diapirs which rise adiabatically from depths in excess of 700 km. As these diapirs undergo pressure-release melting, they also stir in significant portions of the surrounding mantle.

Imatinib Mesylate in Treating Patients With Relapsed or Refractory Solid Tumors of Childhood

ClinicalTrials.gov

2015-04-14

Childhood Desmoplastic Small Round Cell Tumor; Childhood Synovial Sarcoma; Gastrointestinal Stromal Tumor; Lung Metastases; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

Study of Genistein in Pediatric Oncology Patients (UVA-Gen001)

ClinicalTrials.gov

2017-06-20

Lymphoma; Childhood Lymphoma; Solid Tumor; Childhood Solid Tumor; Neuroblastoma; Ewing Sarcoma; Hodgkin Lymphoma; Non-Hodgkin Lymphoma; Rhabdomyosarcoma; Soft Tissue Sarcoma; Medulloblastoma; Germ Cell Tumor; Wilms Tumor; Brain Neoplasms; Medulloblastoma, Childhood; Neuroectodermal Tumors, Primitive

In vivo transduction of primitive mobilized hematopoietic stem cells after intravenous injection of integrating adenovirus vectors

PubMed Central

Richter, Maximilian; Saydaminova, Kamola; Yumul, Roma; Krishnan, Rohini; Liu, Jing; Nagy, Eniko-Eva; Singh, Manvendra; Izsvák, Zsuzsanna; Cattaneo, Roberto; Uckert, Wolfgang; Palmer, Donna; Ng, Philip; Haworth, Kevin G.; Kiem, Hans-Peter; Ehrhardt, Anja; Papayannopoulou, Thalia

2016-01-01

Current protocols for hematopoietic stem/progenitor cell (HSPC) gene therapy, involving the transplantation of ex vivo genetically modified HSPCs are complex and not without risk for the patient. We developed a new approach for in vivo HSPC transduction that does not require myeloablation and transplantation. It involves subcutaneous injections of granulocyte-colony-stimulating factor/AMD3100 to mobilize HSPCs from the bone marrow (BM) into the peripheral blood stream and the IV injection of an integrating, helper-dependent adenovirus (HD-Ad5/35++) vector system. These vectors target CD46, a receptor that is uniformly expressed on HSPCs. We demonstrated in human CD46 transgenic mice and immunodeficient mice with engrafted human CD34+ cells that HSPCs transduced in the periphery home back to the BM where they stably express the transgene. In hCD46 transgenic mice, we showed that our in vivo HSPC transduction approach allows for the stable transduction of primitive HSPCs. Twenty weeks after in vivo transduction, green fluorescent protein (GFP) marking in BM HSPCs (Lin−Sca1+Kit− cells) in most of the mice was in the range of 5% to 10%. The percentage of GFP-expressing primitive HSPCs capable of forming multilineage progenitor colonies (colony-forming units [CFUs]) increased from 4% of all CFUs at week 4 to 16% at week 12, indicating transduction and expansion of long-term surviving HSPCs. Our approach was well tolerated, did not result in significant transduction of nonhematopoietic tissues, and was not associated with genotoxicty. The ability to stably genetically modify HSPCs without the need of myeloablative conditioning is relevant for a broader clinical application of gene therapy. PMID:27554082

The role of immunohistochemistry in medullomyoblastoma--a case series highlighting divergent differentiation.

PubMed

Sachdeva, Man Updesh S; Vankalakunti, Mahesha; Rangan, Aruna; Radotra, Bishan D; Chhabra, Rajesh; Vasishta, Rakesh K

2008-04-25

To analyse the histo-morphology of cases of medullomyoblastoma and identifying its divergent differentiation. A retrospective review of all cases reported as medulloblastoma between the period of Jan 2000 to Dec 2006 was carried out on Hematoxylin and eosin (H & E) stained slides. The cases were screened on light microscopy for primitive neuroectodermal component of a medulloblastoma accompanied by areas of "myoid" differentiation, identified on the basis of presence of strap cells (indicating a clear skeletal muscle differentiation) and/or large anaplastic cells with vescicular nuclei and moderate to abundant amount of eosinophilic cytoplasm. All these cases were subjected to a panel of immunohistochemical stains, including Desmin, GFAP, NFP, HMB45, SMA, S100, CK and EMA. Ultrastructural analysis was done on tissue obtained from paraffin blocks in 2 cases. Male predominance (M:F = 5:1) was noted with an incidence of five percent of all cases of medulloblastoma (6 out of 120 cases) over a period of 6 years. Primitive neuroectodermal areas were accompanied with areas of "myoid" differentiation, 5 cases showing strap cells. Two cases with epithelial and cartilaginous differentiation were seen. Three cases showed focal melanocytic differentiation, identified only on HMB45 immunostaining. Four cases showed glial differentiation. Neuronal differentiation again was very focally seen in two cases, of which one was identified only by NFP immunostain. Seventh case is included in the study, however it is not considered to calculate incidence as it occurred beyond the period of 6 years of records search. Medullomyoblastoma is a rare childhood tumor of cerebellum. Majority of cases reveal divergent differentiation, which are identified with the help of panel of immunostains indicating multi-potential nature of primitive neuroectodermal cells.

Phase equilibria and geochemical constraints on the petrogenesis of high-Ti picrite from the Paleogene East Greenland flood basalt province

NASA Astrophysics Data System (ADS)

Zhang, Yi-Shen; Hou, Tong; Veksler, Ilya V.; Lesher, Charles E.; Namur, Olivier

2018-02-01

Phase equilibrium experiments have been performed on an extremely high-Ti (5.4 wt.% TiO2) picrite from the base of the Paleogene ( 55 Ma) East Greenland Flood Basalt Province. This sample has a high CaO/Al2O3 ratio (1.14), a steep rare-earth elements (REE) profile, is enriched in incompatible trace elements, and is in chemical equilibrium with highly primitive olivine. This all suggests that the picrite is a near-primary melt that did not suffer major chemical evolution during ascent from the mantle source and through the crust. Near-liquidus phase relations were determined over the pressure range of 1 atm, 1 to 1.5 GPa and at temperatures from 1094 to 1400°C. They provide an important constraint on the petrogenesis of these lavas. The high-Ti picritic melt is multi-saturated with olivine (Ol) + orthopyroxene (Opx) at 1 GPa but has only Ol or Opx on the liquidus at lower and higher pressures, respectively. This indicates the primitive melt was last equilibrated with its mantle source at relatively shallow pressure ( 1 GPa). Melting probably started at 2-3 GPa and the picritic melt was produced by 15-30% melting of the mantle source. Such a degree of partial melting requires a mantle with a high potential temperature (1480-1530˚C). The relatively low CaO content and high FeO/MnO ratios of the most primitive East Greenland picrites, the high Ni content of olivine phenocrysts and the presence of low-Ca pyroxene (i.e., pigeonite) at high pressure in our experiments all suggest that the mantle source contained a major component of garnet pyroxenite. Residual garnet in the source could adequately explain the low Al2O3 content (7.92 wt.%) and steep REE patterns of the picrite sample. However, simple melting of a lherzolitic source, even with a major pyroxenite component, cannot explain the formation of magmas with the very high Ti contents observed in some East Greenland basalts. We therefore propose that magmas highly-enriched in Ti were produced by melting of a metasomatized mantle source containing Ti-enriched amphibole and/or phlogopite.

Globin switches in yolk sac-like primitive and fetal-like definitive red blood cells produced from human embryonic stem cells.

PubMed

Qiu, Caihong; Olivier, Emmanuel N; Velho, Michelle; Bouhassira, Eric E

2008-02-15

We have previously shown that coculture of human embryonic stem cells (hESCs) for 14 days with immortalized fetal hepatocytes yields CD34(+) cells that can be expanded in serum-free liquid culture into large numbers of megaloblastic nucleated erythroblasts resembling yolk sac-derived cells. We show here that these primitive erythroblasts undergo a switch in hemoglobin (Hb) composition during late terminal erythroid maturation with the basophilic erythroblasts expressing predominantly Hb Gower I (zeta(2)epsilon(2)) and the orthochromatic erythroblasts hemoglobin Gower II (alpha(2)epsilon(2)). This suggests that the switch from Hb Gower I to Hb Gower II, the first hemoglobin switch in humans is a maturation switch not a lineage switch. We also show that extending the coculture of the hESCs with immortalized fetal hepatocytes to 35 days yields CD34(+) cells that differentiate into more developmentally mature, fetal liver-like erythroblasts, that are smaller, express mostly fetal hemoglobin, and can enucleate. We conclude that hESC-derived erythropoiesis closely mimics early human development because the first 2 human hemoglobin switches are recapitulated, and because yolk sac-like and fetal liver-like cells are sequentially produced. Development of a method that yields erythroid cells with an adult phenotype remains necessary, because the most mature cells that can be produced with current systems express less than 2% adult beta-globin mRNA.

Gut endoderm takes flight from the wings of mesoderm.

PubMed

McDonald, Angela C H; Rossant, Janet

2014-12-01

The endoderm layer destined to be primitive gut is a mosaic of earlier visceral endoderm and definitive endoderm that arises later, during gastrulation. Live imaging now reveals that in mouse embryos, definitive endoderm cells egress from underlying mesoderm and intercalate into the overlying cell layer. This process requires SOX17-mediated control of basement membrane organization.

Granulocyte-colony stimulating factor and stem cell factor are the crucial factors in long-term culture of human primitive hematopoietic cells supported by a murine stromal cell line.

PubMed

Nishi, N; Ishikawa, R; Inoue, H; Nishikawa, M; Kakeda, M; Yoneya, T; Tsumura, H; Ohashi, H; Yamaguchi, Y; Motoki, K; Sudo, T; Mori, K J

1996-09-01

The findings that murine marrow stromal cell line MS-5 supported the proliferation of human lineage-negative (Lin-) CD34+CD38- bone marrow cells in long-term culture have been reported. In this study, we analyzed this proliferating activity of MS-5-conditioned medium (CM) on human primitive hematopoietic cells. When Lin-CD34+CD38- cells of normal human cord blood cells were co-cultured with MS-5, colony forming cells (CFCs) were maintained over 7 weeks in vitro. Prevention of contact between MS-5 and Lin-CD34+CD38- cells by using membrane filter (0.45 micron) was negligible for this activity. This indicated that the activity of MS-5 on human primitive hematopoietic cells is a soluble factor(s) secreted from MS-5, which is not induced by the contact between MS-5 and Lin-CD34+CD38- cells. We tried to purify this soluble activity. An active material with a molecular weight of about 150 kDa, determined by gel filtration chromatography, solely supported the growth of Lin-CD34+CD38- cells and Mo7e, a human megakaryocytic cell line. This activity not only reacted with anti-mouse stem cell factor (mSCF) antibody on Western blots, but it was also neutralized in the presence of anti-mSCF antibody. Another active material with a molecular weight of about 20-30 kDa synergized with mSCF to stimulate the growth of Lin-CD34+CD38- cells but failed to do so alone, although this synergy was inhibited in the presence of soluble mouse granulocyte-colony stimulating factor (mG-CSF) receptor, which is a chimeric protein consisting of the extracellular domain of mG-CSF receptor and the Fe region of human IgG1. In addition, the latter molecule supported the growth of the G-CSF dependent cell line FD/GR3, which is a murine myeloid leukemia cell line, FDC-P2, transfected with mG-CSF receptor cDNA. Adding of anti-mSCF antibody and soluble mG-CSF receptor to the culture completely abrogated the activity of MS-5-CM. Recombinant (r) mSCF and rmG-CSF had synergistic activity on the growth of Lin-CD34+CD38- cells. These results indicated that the activity on Lin-CD34+CD38- cells included in MS-5-CM is based upon the synergistic effects of mSCF and mG-CSF.

A knowledge based system for scientific data visualization

NASA Technical Reports Server (NTRS)

Senay, Hikmet; Ignatius, Eve

1992-01-01

A knowledge-based system, called visualization tool assistant (VISTA), which was developed to assist scientists in the design of scientific data visualization techniques, is described. The system derives its knowledge from several sources which provide information about data characteristics, visualization primitives, and effective visual perception. The design methodology employed by the system is based on a sequence of transformations which decomposes a data set into a set of data partitions, maps this set of partitions to visualization primitives, and combines these primitives into a composite visualization technique design. Although the primary function of the system is to generate an effective visualization technique design for a given data set by using principles of visual perception the system also allows users to interactively modify the design, and renders the resulting image using a variety of rendering algorithms. The current version of the system primarily supports visualization techniques having applicability in earth and space sciences, although it may easily be extended to include other techniques useful in other disciplines such as computational fluid dynamics, finite-element analysis and medical imaging.

Advanced texture filtering: a versatile framework for reconstructing multi-dimensional image data on heterogeneous architectures

NASA Astrophysics Data System (ADS)

Zellmann, Stefan; Percan, Yvonne; Lang, Ulrich

2015-01-01

Reconstruction of 2-d image primitives or of 3-d volumetric primitives is one of the most common operations performed by the rendering components of modern visualization systems. Because this operation is often aided by GPUs, reconstruction is typically restricted to first-order interpolation. With the advent of in situ visualization, the assumption that rendering algorithms are in general executed on GPUs is however no longer adequate. We thus propose a framework that provides versatile texture filtering capabilities: up to third-order reconstruction using various types of cubic filtering and interpolation primitives; cache-optimized algorithms that integrate seamlessly with GPGPU rendering or with software rendering that was optimized for cache-friendly "Structure of Array" (SoA) access patterns; a memory management layer (MML) that gracefully hides the complexities of extra data copies necessary for memory access optimizations such as swizzling, for rendering on GPGPUs, or for reconstruction schemes that rely on pre-filtered data arrays. We prove the effectiveness of our software architecture by integrating it into and validating it using the open source direct volume rendering (DVR) software DeskVOX.

Prebiotic synthesis in atmospheres containing CH4, CO, and CO2. I - Amino acids

NASA Technical Reports Server (NTRS)

Schlesinger, G.; Miller, S. L.

1983-01-01

The prebiotic synthesis of amino acids, HCN, H2CO, and NH3 using a spark discharge on various simulated primitive earth atmospheres at 25 C is investigated. Various mixtures of CH4, CO, CO2, N2, NH3, H2O, and H2 were utilized in different experiments. The yields of amino acids (1.2-4.7 percent based on the carbon) are found to be approximately independent of the H2/CH4 ratio and the presence of NH3, and a wide variety of amino acids are obtained. Glycine is found to be almost the only amino acid produced from CO and CO2 model atmospheres, with the maximum yield being about the same for the three carbon sources at high H2/carbon ratios,whereas CH4 is superior at low H2/carbon ratios. In addition, it is found that the directly synthesized NH3 together with the NH3 obtained from the hydrolysis of HCN, nitriles, and urea could have been a major source of ammonia in the atmosphere and oceans of the primitive earth. It is determined that prebiotic syntheses from HCN and H2CO to give products such as purines and sugars and some amino acids could have occurred in primitive atmospheres containing CO and CO2 provided the H2/CO and H2/CO2 ratios were greater than about 1.0.

Unified structure theory of icosahedral quasicrystals: Evidence from neutron powder diffraction patterns that AlCrFeMnSi, AlCuLiMg, and TiNiFeSi icosahedral quasicrystals are twins of cubic crystals containing about 820 or 1012 atoms in a primitive unit cube

PubMed Central

Pauling, Linus

1988-01-01

A unified structure theory of icosahedral quasicrystals, combining the twinned-cubic-crystal theory and the Penrose-tiling-six-dimensional-projection theory, is described. Values of the primitive-cubic lattice constant for several quasicrystals are evaluated from x-ray and neutron diffraction data. The fact that the low-angle diffraction maxima can be indexed with cubic unit cells provides additional support for the twinned-cubic-crystal theory of icosahedral quasicrystals. PMID:16593990

Primary primitive neuroectodermal tumor of the cervix

PubMed Central

Li, Bo; Ouyang, Ling; Han, Xue; Zhou, Yang; Tong, Xin; Zhang, Shulang; Zhang, Qingfu

2013-01-01

Primary primitive neuroectodermal tumors (PNETs) are rare and high-grade malignant tumors that mostly occur in children and young adults. The most common sites are the trunk, limbs, and retroperitoneum. Herein, we present a case of a PNET involving the cervix uteri in a 27-year-old woman. The lesion showed characteristic histologic features of a PNET and was positive for the immunohistochemical markers cluster of differentiation (CD) 99, vimentin, neuron-specific enolase, neural cell adhesion molecule 1 (CD56), and CD117 (c-kit), further defining the tumor while helping to confirm PNET. The clinical Stage IIIB tumor was treated with chemotherapy and radiotherapy. PMID:23836982

Spectrum of hemoglobinopathies among the primitive tribes: a multicentric study in India.

PubMed

Mohanty, Dipika; Mukherjee, Malay B; Colah, Roshan B; Wadia, Mahrukh; Ghosh, Kanjaksha; Chottray, Guru Prasad; Jain, Dipty; Italia, Yazdi; Ashokan, Kumar S; Kaul, Rajni; Shukla, Deepak K; Muthuswamy, Vasantha

2015-03-01

We evaluated the spectrum of hemoglobinopathies among the primitive tribal groups from 4 states in India. A total of 15,200 individuals from 14 primitive tribal groups were studied by automated high-performance liquid chromatography. The hemoglobin S (HbS) allele frequency varied from 0.011 to 0.120 and the β-thalassemia allele frequency from 0.005 to 0.024. It is interesting to note that a very high HbS allele frequency was observed among the Dravidian (0.060-0.120) and Indo-European (0.060-0.076) as compared with Austro-Asiatic (0.011-0.022) speaking tribal groups. Although statistical analysis of the data did not show any ethnic differences within the states, regional differences were observed between the states for both HbS and β-thalassemia traits. HbS was found to be the most common hemoglobinopathy followed by β-thalassemia. A health plan for identifying sickle-cell homozygotes in the neonatal period with proper medical intervention is desirable. © 2013 APJPH.

Oxygen and the evolution of metabolic pathways

NASA Technical Reports Server (NTRS)

Jahnke, L. L.

1986-01-01

While a considerable amount of evidence has been accumulated about the history of oxygen on this planet, little is known about the relative amounts to which primitive cells might have been exposed. One clue may be found in the metabolic pathways of extant microorganisms. While eucaryotes are principally aerobic organisms, a number are capable of anaerobic growth by fermentation. One such eucaryotic microorganism, Saccharomyces cerevisiae, will grow in the complete absence of oxygen when supplemented with unsaturated fatty acid and sterol. Oxygen-requiring enzymes are involved in the synthesis of both of these compounds. Studies have demonstrated that the oxidative desaturation of palmitic acid and the conversion of squalene to sterols occur in the range of 10-(3) to 10(-2) PAL. Thus, if the oxygen requirements of these enzymatic processes are an indication, eucaryotes might be more primitive than anticipated from the microfossil record. Results of studies on the oxygen requirements for sterol and unsaturated fatty acid synthesis in a more primitive procaryotic system are also discussed.

Immunocytochemical location of pituitary cells containing ACTH, alpha-MSH, and beta-endorphin in Acipenser transmontanus, Lepisosteus spatula, and Amia calva.

PubMed

Joss, J M; Dores, R M; Crim, J W; Beshaw, M

1990-06-01

This immunocytochemical study of the pituitaries of the primitive actinopterygians, Acipenser transmontanus, Lepisosteus spatula, and Amia calva, showed a strict delineation between the hormonal fragments of proopiomelanocorticotropin (POMC) produced by corticotropes of the pars distalis and the melanotropes of the pars intermedia. Corticotropes were immunoreactive only for ACTH and not to either of the further degradation products, alpha-MSH or beta-endorphin. Melanotropes were shown to be immunoreactive to all three antisera but it is argued that immunoreactivity of melanotropes to ACTH antiserum is due to that antiserum's cross-reactivity with the cleavage product corticotropin-like intermediate peptide. The PAS positivity of both the corticotropes and the melanotropes of all three primitive fish argues for an ancient origin of a carbohydrate component of POMC and for its loss or reduction in teleosts where these cells are PAS negative.

Ripple/Carcinoid pattern sebaceoma with apocrine differentiation.

PubMed

Misago, Noriyuki; Narisawa, Yutaka

2011-02-01

Sebaceoma is a benign sebaceous neoplasm, which has been reported to show characteristic growth patterns, such as, ripple, labyrinthine/sinusoidal, and carcinoid-like patterns. Another recent finding regarding in sebaceoma is the observation of apocrine differentiation within the sebaceoma lesion. This report describes a case of carcinoid (a partial ripple and labyrinthine) pattern sebaceoma with apocrine differentiation with a literature review and immunohistochemical studies. The various characteristic growth patterns in sebaceoma were suggested to simply be variations of the same growth pattern arranged in cords, namely, a unified term "ripple/carcinoid pattern." The primitive sebaceous germinative cells in sebaceoma may still have the ability to undergo apocrine differentiation. Most of the reports so far on sebaceoma with apocrine differentiation, including the present case, describe a ripple/carcinoid pattern, thus suggesting that ripple/carcinoid pattern sebaceoma is composed of more primitive sebaceous germinative cells than conventional sebaceoma.

Combination Chemotherapy in Treating Patients With Non-Metastatic Extracranial Ewing Sarcoma

ClinicalTrials.gov

2018-02-09

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Childhood Supratentorial Primitive Neuroectodermal Tumor; Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Extraosseous Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Peripheral Primitive Neuroectodermal Tumor of the Kidney; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

Proceedings of the Midwinter Conference of Immunologists (28th) Held in Pacific Grove, California on 28-31 January 1989 (Lymphocyte Differentiation)

DTIC Science & Technology

1989-02-24

N. Witte Sf-ak-r’." OWEN N. WITTE University of California, Los Angeles, CA "Oncogene Interactions with Primitive Lymphoid Cells" DAVID BALTIMORE The...as Schwann cells, myotubes and astroglial cells. Neurons use different receptors to interact with different cell types. Different neu-ons also differ...controlled by a clock in the progenitor cell that is driven by platelet- derived growth factor (PDGF) secreted by type-i astrocytes. Type-2 astrocyte

Characterization of a Weak Allele of Zebrafish cloche Mutant

PubMed Central

Ma, Ning; Huang, Zhibin; Chen, Xiaohui; He, Fei; Wang, Kun; Liu, Wei; Zhao, Linfeng; Xu, Xiangmin; Liao, Wangjun; Ruan, Hua; Luo, Shenqiu; Zhang, Wenqing

2011-01-01

Hematopoiesis is a complicated and dynamic process about which the molecular mechanisms remain poorly understood. Danio rerio (zebrafish) is an excellent vertebrate system for studying hematopoiesis and developmental mechanisms. In the previous study, we isolated and identified a cloche 172 (clo 172) mutant, a novel allele compared to the original cloche (clo) mutant, through using complementation test and initial mapping. Here, according to whole mount in-situ hybridization, we report that the endothelial cells in clo 172 mutant embryos, although initially developed, failed to form the functional vascular system eventually. In addition, further characterization indicates that the clo 172 mutant exhibited weaker defects instead of completely lost in primitive erythroid cells and definitive hematopoietic cells compared with the clo s5 mutant. In contrast, primitive myeloid cells were totally lost in clo 172 mutant. Furthermore, these reappeared definitive myeloid cells were demonstrated to initiate from the remaining hematopoietic stem cells (HSCs) in clo 172 mutant, confirmed by the dramatic decrease of lyc in clo 172 runx1w84x double mutant. Collectively, the clo 172 mutant is a weak allele compared to the clo s5 mutant, therefore providing a model for studying the early development of hematopoietic and vascular system, as well as an opportunity to further understand the function of the cloche gene. PMID:22132109

Fine-Needle Aspiration of Metastatic Central Type Primitive Neuroectodermal Tumors in Patients with a Germ Cell Tumor.

PubMed

Chen, Shaoxiong; Idrees, Muhammad; Lin, Jingmei; Wu, Howard H

2017-01-01

Central type primitive neuroectodermal tumors (PNET) are some of the most frequent somatic type tumors derived from germ cell tumors and can metastasize. We studied the cytomorphological features of metastatic central type PNET by fine-needle aspiration (FNA). A computerized search of our laboratory information system was performed for the 9-year period from 2005 through 2014 to identify all cytology cases in which a diagnosis of metastatic central type PNET had been rendered. A total of 5 FNA cases were collected and direct smears were reexamined. All patients had a history of testicular or ovarian germ cell tumors. Direct smears displayed single and clusters of atypical round to oval cells with scant to moderate cytoplasm. Abundant naked nuclei were present in Diff-Quik-stained smears with mild to marked crushed artifacts and nuclear molding. Tumor cells showed fine granular chromatin, nuclear size variation (up to 1:3), and one or more small nucleoli. Pseudorosettes (Homer Wright-like rosette) were noticed in 1 case. Tumor cells were commonly positive for synaptophysin. Metastatic PNET can be reliably diagnosed by FNA. Differential diagnoses include Ewing sarcoma/peripheral PNET, alveolar rhabdomyosarcoma, neuroblastoma, etc. It is important to be familiar with this entity to avoid diagnostic pitfalls. © 2017 S. Karger AG, Basel.

Design of a nanocomposite substrate inducing adult stem cell assembly and progression toward an Epiblast-like or Primitive Endoderm-like phenotype via mechanotransduction.

PubMed

Morena, Francesco; Armentano, Ilaria; Montanucci, Pia; Argentati, Chiara; Fortunati, Elena; Montesano, Simona; Bicchi, Ilaria; Pescara, Teresa; Pennoni, Ilaria; Mattioli, Samantha; Torre, Luigi; Latterini, Loredana; Emiliani, Carla; Basta, Giuseppe; Calafiore, Riccardo; Kenny, Josè Maria; Martino, Sabata

2017-11-01

This work shows that the active interaction between human umbilical cord matrix stem cells and Poly (l-lactide)acid (PLLA) and PLLA/Multi Walled Carbon Nanotubes (MWCNTs) nanocomposite films results in the stem cell assembly as a spheroid conformation and affects the stem cell fate transition. We demonstrated that spheroids directly respond to a tunable surface and the bulk properties (electric, dielectric and thermal) of plain and nanocomposite PLLA films by triggering a mechanotransduction axis. This stepwise process starts from tethering of the cells' focal adhesion proteins to the surface, together with the adherens junctions between cells. Both complexes transmit traction forces to F-Actin stress fibres that link Filamin-A and Myosin-IIA proteins, generating a biological scaffold, with increased stiffening conformation from PLLA to PLLA/MWCNTs, and enable the nucleoskeleton proteins to boost chromatin reprogramming processes. Herein, the opposite expression of NANOG and GATA6 transcription factors, together with other lineage specification related proteins, steer spheroids toward an Epiblast-like or Primitive Endoderm-like lineage commitment, depending on the absence or presence of 1 wt% MWCNTs, respectively. This work represents a pioneering effort to create a stem cell/material interface that can model the stem cell fate transition under growth culture conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integration and long distance axonal regeneration in the central nervous system from transplanted primitive neural stem cells.

PubMed

Zhao, Jiagang; Sun, Woong; Cho, Hyo Min; Ouyang, Hong; Li, Wenlin; Lin, Ying; Do, Jiun; Zhang, Liangfang; Ding, Sheng; Liu, Yizhi; Lu, Paul; Zhang, Kang

2013-01-04

Spinal cord injury (SCI) results in devastating motor and sensory deficits secondary to disrupted neuronal circuits and poor regenerative potential. Efforts to promote regeneration through cell extrinsic and intrinsic manipulations have met with limited success. Stem cells represent an as yet unrealized therapy in SCI. Recently, we identified novel culture methods to induce and maintain primitive neural stem cells (pNSCs) from human embryonic stem cells. We tested whether transplanted human pNSCs can integrate into the CNS of the developing chick neural tube and injured adult rat spinal cord. Following injection of pNSCs into the developing chick CNS, pNSCs integrated into the dorsal aspects of the neural tube, forming cell clusters that spontaneously differentiated into neurons. Furthermore, following transplantation of pNSCs into the lesioned rat spinal cord, grafted pNSCs survived, differentiated into neurons, and extended long distance axons through the scar tissue at the graft-host interface and into the host spinal cord to form terminal-like structures near host spinal neurons. Together, these findings suggest that pNSCs derived from human embryonic stem cells differentiate into neuronal cell types with the potential to extend axons that associate with circuits of the CNS and, more importantly, provide new insights into CNS integration and axonal regeneration, offering hope for repair in SCI.

On Synchronization Primitive Systems.

DTIC Science & Technology

The report studies the question: what synchronization primitive should be used to handle inter-process communication. A formal model is presented...between these synchronization primitives. Although only four synchronization primitives are compared, the general methods can be used to compare other... synchronization primitives. Moreover, in the definitions of these synchronization primitives, conditional branches are explicitly allowed. In addition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, G.C.; Stevens, P.R.; Rittenberg, A.

A compilation is presented of reaction data taken from experimental high energy physics journal articles, reports, preprints, theses, and other sources. Listings of all the data are given, and the data points are indexed by reaction and momentum, as well as by their source document. Much of the original compilation was done by others working in the field. The data presented also exist in the form of a computer-readable and searchable database; primitive access facilities for this database are available.

Chemical evolution and the origin of life

NASA Technical Reports Server (NTRS)

Oro, J.

1983-01-01

A review is presented of recent advances made in the understanding of the formation of carbon compounds in the universe and the occurrence of processes of chemical evolution. Topics discussed include the principle of evolutionary continuity, evolution as a fundamental principle of the physical universe, the nuclear synthesis of biogenic elements, organic cosmochemistry and interstellar molecules, the solar nebula and the solar system in chemical evolution, the giant planets and Titan in chemical evolution, and comets and their interaction with the earth. Also examined are carbonaceous chondrites, environment of the primitive earth, energy sources available on the primitive earth, the synthesis of biochemical monomers and oligomers, the abiotic transcription of nucleotides, unified prebiotic and enzymatic mechanisms, phospholipids and membranes, and protobiological evolution.

Resolving Early Mesoderm Diversification through Single Cell Expression Profiling

PubMed Central

Wilson, Nicola K.; Macaulay, Iain C.; Marioni, John C.; Göttgens, Berthold

2016-01-01

Summary In mammals, specification of the three major germ layers occurs during gastrulation, when cells ingressing through the primitive streak differentiate into the precursor cells of major organ systems. However, the molecular mechanisms underlying this process remain unclear, as numbers of gastrulating cells are very limited. In the E6.5 mouse embryo, cells located at the junction between the extra-embryonic region and the epiblast on the posterior side of the embryo undergo an epithelial-to-mesenchymal transition (EMT) and ingress through the primitive streak (PS). Subsequently, cells migrate, either surrounding the prospective ectoderm contributing to the embryo proper, or into the extra-embryonic region to form the yolk sac (YS), umbilical cord and placenta. Fate mapping has shown that mature tissues such as blood and heart originate from specific regions of the pre-gastrula epiblast1 but the plasticity of cells within the embryo and the function of key cell type-specific transcription factors remain unclear. Here we analyse 1,205 cells from the epiblast and nascent Flk1+ mesoderm of gastrulating mouse embryos using single cell RNA-sequencing, representing the first transcriptome-wide in vivo view of early mesoderm formation during mammalian gastrulation. Additionally, using knock-out mice, we study the function of Tal1, a key hematopoietic transcription factor (TF), and demonstrate, contrary to previous studies performed using retrospective assays2,3, that Tal1 knock out does not immediately bias precursor cells towards a cardiac fate. PMID:27383781

Concepts in Practice as Sources of Order

ERIC Educational Resources Information Center

Hutchins, Edwin

2012-01-01

The framework for the study of concept formation embraced by the articles in this special issue makes it possible to observe and catalog the mechanisms by which conceptual structures in the wild achieve and maintain organization. I propose a provisional inventory of such mechanisms that includes the primitive mechanisms of dimensionality…

CD34+ Testicular Stromal Cells Support Long-Term Expansion of Embryonic and Adult Stem and Progenitor Cells

PubMed Central

Kim, Jiyeon; Seandel, Marco; Falciatori, Ilaria; Wen, Duancheng; Rafii, Shahin

2010-01-01

Stem cells reside in specialized microenvironments created by supporting stromal cells that orchestrate self-renewal and lineage-specific differentiation. However, the precise identity of the cellular and molecular pathways that support self-renewal of stem cells is not known. For example, long-term culture of prototypical stem cells, such as adult spermatogonial stem and progenitor cells (SPCs), in vitro has been impeded by the lack of an optimal stromal cell line that initiates and sustains proliferation of these cells. Indeed, current methods, including the use of mouse embryonic fibroblasts (MEFs), have not been efficient and have generally led to inconsistent results. Here, we report the establishment of a novel CD34-positive cell line, referred to as JK1, derived from mouse testicular stromal cells that not only facilitated long-term SPC culture but also allowed faithful generation of SPCs and multipotent stem cells. SPCs generated on JK1 maintained key features of germ line stem cells, including expression of PLZF, DAZL, and GCNA. Furthermore, these feeders also promoted the long-term cultivation of other types of primitive cells including multi-potent adult spermatogonial-derived stem cells, pluripotent murine embryonic stem cells, and embryonic germ cells derived from primordial germ cells. Stem cells could be passaged serially and still maintained expression of characteristic markers such as OCT4 and NANOG in vitro, as well as the ability to generate all three germ layers in vivo. These results indicate that the JK1 cell line is capable of promoting long-term culture of primitive cells. As such, this cell line allows for identification of stromal-derived factors that support long-term proliferation of various types of stem cells and constitutes a convenient alternative to other types of feeder layers. PMID:18669907

MiRNA-mediated regulation of cell signaling and homeostasis in the early mouse embryo.

PubMed

Pernaute, Barbara; Spruce, Thomas; Rodriguez, Tristan A; Manzanares, Miguel

2011-02-15

At the time of implantation the mouse embryo is composed of three tissues the epiblast, trophectoderm and primitive endoderm. As development progresses the epiblast goes on to form the foetus whilst the trophectoderm and primitive endoderm give rise to extra-embryonic structures with important roles in embryo patterning and nutrition. Dramatic changes in gene expression occur during early embryo development and these require regulation at different levels. miRNAs are small non coding RNAs that have emerged over the last decade as important post-transcriptional repressors of gene expression. The roles played by miRNAs during early mammalian development are only starting to be elucidated. In order to gain insight into the function of miRNAs in the different lineages of the early mouse embryo we have analysed in depth the phenotype of embryos and extra-embryonic stem cells mutant for the miRNA maturation protein Dicer. This study revealed that miRNAs are involved in regulating cell signaling and homeostasis in the early embryo. Specifically, we identified a role for miRNAs in regulating the Erk signaling pathway in the extra-embryonic endoderm, cell cycle progression in extra-embryonic tissues and apoptosis in the epiblast.

Notochord Morphogenesis in Mice: Current Understanding & Open Questions

PubMed Central

Balmer, Sophie; Nowotschin, Sonja; Hadjantonakis, Anna-Katerina

2016-01-01

The notochord is the structure which defines chordates. It is a rod-like mesodermal structure that runs the anterior-posterior length of the embryo, adjacent to the ventral neural tube. The notochord plays a critical role in embryonic tissue patterning, for example the dorsal-ventral patterning of the neural tube. The cells that will come to form the notochord are specified at gastrulation. Axial mesodermal cells arising at the anterior primitive streak migrate anteriorly as the precursors of the notochord and populate the notochordal plate. Interestingly, even though a lot of interest has centered on investigating the functional and structural roles of the notochord, we still have a very rudimentary understanding of notochord morphogenesis. The events driving the formation of the notochord are rapid, taking place over the period of approximately a day in mice. In this commentary we provide an overview of our current understanding of mouse notochord morphogenesis, from the initial specification of axial mesendodermal cells at the primitive streak, the emergence of these cells at the midline on the surface of the embryo, to their submergence and organization of the stereotypically positioned notochord. We will also discuss some key open questions. PMID:26845388

The physics of cellular synthesis, growth and division

NASA Technical Reports Server (NTRS)

Pollard, E. C.

1974-01-01

Three areas of research in NASA'S University Program are described. Primitive terrestrial living cells were studied as a guide to the kind of cells to look for in extraterrestrial life. Experiments in zero gravity conditions are described with emphasis upon effects on small organisms. The effects of ionizing radiation on cells are studied so that it will be possible to predict dosages which can be tolerated by humans with no permanent damage.

[Clinicopathologic study of sinonasal teratocarcinosarcoma and its contrast with olfactory neuroblastoma].

PubMed

Li, Xue; Liu, Hong-Gang; Xie, Xin-Ji; Han, Yi-Ding; Li, Ming

2008-07-01

To study the clinicopathologic features, diagnosis and differential diagnosis of sinonasal teratocarcinosarcoma (SNTCS) and olfactory neuroblastoma (ONB), and to discuss the histogenesis and possible relationship between SNTCS and ONB. Seven cases of SNTCS and 34 cases of ONB were retrieved from the pathological archives together with one case each of malignant teratoma and immature embryonic tissue at 8 weeks were collected from Beijing Tongren Hospital. The clinicopathologic features were analyzed and immunohistochemical staining was performed on paraffin sections. Six of the SNTCS patients were male and one was female. The patients age range was 25 to 69 years (mean age 46). Four cases were initial presentation and three were recurrences. Histologically, the tumor shows multiple tissue components derived from three germ layers. There were mixture of teratoma-like tissue and carcinosarcoma. The components include fetal clear cell squamous epithelium derived from ectoderm. Glandular and tubular structures and ciliated columnar epithelium derived from endoderm. Fibroblasts, striated muscle, smooth muscle, cartilage and osteoid matrix derived from mesoderm. The carcinoma component exhibited mostly adenocarcinoma and squamous cell carcinoma, whereas the sarcoma component mostly exhibited rhabdomyosarcoma, leiomyosarcoma, and fibrosarcoma. In addition, carcinoid, and primitive mesenchymal tissue and the ONB component were also seen. The morphological characteristics of SNTCS comprised fetal clear cell squamous epithelium, carcinosarcoma and the ONB component. By immunohistochemistry, the epithelial component and cells with epithelium differentiation were positive for cytokeratin (pan) and EMA. The ONB component was positive for Syn, NSE, CD99, NF and CgA to different degrees. Neurofibril bundles were positive for S-100, and Flexner-Wintersteiner rosettes expressed cytokeratin (pan) and EMA. The spindle cells expressed vimentin, SMA, desmin, myosin and myoglobin. The primitive mesenchymal tissue expressed vimentin, and the mucoid materials and glycogen were positive for PAS. GFAP was negative in all cases. The 34 cases of ONB, included 18 men and 16 women, the age ranged from 12 to 72 years (mean 42.8 years). Microscopically, the tumor shows epithelial nests, net of angioma-like fibrous connective tissues, small round and spindle cells, glandular, squamous-like cells, and cells of rhabdomyoblastic differentiation, Homer-Wright and Flexner rosette, bundles of neurofibrils, etc. NSE and CgA were expressed in small cells. S-100 protein was positive in the areas of bunches of neurofibril. Cytokeratin (pan) was positive in epithelial cells. Myoglobin was positive in the cells of rhabdomyoblastic differentiation. The single case of immature malignant teratoma exhibited primitive nerve tissue, but fetal clear cell squamous epithelium was not found. In the immature embryonic tissue, rudimentary organs were formed, with fetal clear cell squamous epithelium lining present on the nasal and oral cavities surface. SNTCS is a rare and aggressive malignant neoplasm. Most of ONB are low-grade malignant tumors. Morphological differences are the most important basis to make differentiate SNTCS from ONB. As SNTCS may demonstrate a multiplicity of structures and pleomorphism, inadequate sampling at biopsy, therefore, may lead to errors in diagnosis. No evidence show that SNTCS are derived from germ cells and sinonasal teratoid carcinosarcoma may be a more proper name. SNTCS probably arises from primitive totipotential cells of olfactory/sinonasal membrane, and the relationship between SNTCS and ONB needs further study.

A novel growth-promoting microbe, Methylobacterium funariae sp. nov., isolated from the leaf surface of a common moss.

PubMed

Schauer, S; Kutschera, U

2011-04-01

Land plants (embryophytes) evolved in the presence of prokaryotic microbes. As a result, numerous mutually beneficial associations (symbioses) developed that can be analyzed using a variety of methods. Here we describe the isolation and characterization of a new pink-pigmented facultatively methylotrophic symbiotic bacterium of the genus Methylobacterium (laboratory strain F3.2) that was isolated from the gametophytic phylloids of the common cord moss Funaria hygrometrica Hedw. Plantlets were collected in the field and analyzed in the laboratory. Colonies of methylobacteria were obtained by the agar-impression-method. Based on its unique phenotype (the bacterial cells are characterized by fimbriae-like appendages), a comparative 16S rRNA gene (DNA) sequence analysis, and an average DNA-DNA hybridization value of 8,4 %, compared with its most closely related sister taxon, this isolate is described as a new species, Methylobacterium funariae sp. nov. (type strain F3.2). This new epiphytic bacterium inhabits the leaf surface of "primitive" land plants such as mosses and interacts with its host organism via the secretion of phytohormones (cytokinines, auxins). These external signals are perceived by the plant cells that divide and grow more rapidly than in the absence of their prokaryotic phytosymbionts. We suggest that M. funariae sp. nov. uses methanol emitted from the stomatal pores as principal carbon source for cell metabolism. However, our novel data indicate that, in this unique symbiotic plant-microbe interaction, the uptake of amino acids leached from the surface of the epidermal cells of the green host organism may be of importance as microbial carbon- and nitrogen-source.

An Animal Model to Investigate the Potential for Breast Cancer Metastatic Dissemination Following Surgery Intervention on the Primitive Tumor

DTIC Science & Technology

2010-09-01

cancer cells at the plasma membrane level were measured by cell surface biotinylation, using a dedicated kit (cat. #89881) obtained from Pierce...each form of the receptor at the plasma membrane of transfected cells was confirmed by isolation of cell surface proteins obtained by biotinylation...this receptor to interact with both plasma membrane-bound and soluble FKN. Based on our study, it seems reasonable to postulate that the dissemination

Single-lineage transcriptome analysis reveals key regulatory pathways in primitive erythroid progenitors in the mouse embryo

PubMed Central

Isern, Joan; He, Zhiyong; Fraser, Stuart T.; Nowotschin, Sonja; Ferrer-Vaquer, Anna; Moore, Rebecca; Hadjantonakis, Anna-Katerina; Schulz, Vincent; Tuck, David; Gallagher, Patrick G.

2011-01-01

Primitive erythroid (EryP) progenitors are the first cell type specified from the mesoderm late in gastrulation. We used a transgenic reporter to image and purify the earliest blood progenitors and their descendants from developing mouse embryos. EryP progenitors exhibited remarkable proliferative capacity in the yolk sac immediately before the onset of circulation, when these cells comprise nearly half of all cells of the embryo. Global expression profiles generated at 24-hour intervals from embryonic day 7.5 through 2.5 revealed 2 abrupt changes in transcript diversity that coincided with the entry of EryPs into the circulation and with their late maturation and enucleation, respectively. These changes were paralleled by the expression of critical regulatory factors. Experiments designed to test predictions from these data demonstrated that the Wnt-signaling pathway is active in EryP progenitors, which display an aerobic glycolytic profile and the numbers of which are regulated by transforming growth factor-β1 and hypoxia. This is the first transcriptome assembled for a single hematopoietic lineage of the embryo over the course of its differentiation. PMID:21263157

Early Lineage Priming by Trisomy of Erg Leads to Myeloproliferation in a Down Syndrome Model

PubMed Central

Ng, Ashley P.; Hu, Yifang; Metcalf, Donald; Hyland, Craig D.; Ierino, Helen; Phipson, Belinda; Wu, Di; Baldwin, Tracey M.; Kauppi, Maria; Kiu, Hiu; Di Rago, Ladina; Hilton, Douglas J.; Smyth, Gordon K.; Alexander, Warren S.

2015-01-01

Down syndrome (DS), with trisomy of chromosome 21 (HSA21), is the commonest human aneuploidy. Pre-leukemic myeloproliferative changes in DS foetal livers precede the acquisition of GATA1 mutations, transient myeloproliferative disorder (DS-TMD) and acute megakaryocytic leukemia (DS-AMKL). Trisomy of the Erg gene is required for myeloproliferation in the Ts(1716)65Dn DS mouse model. We demonstrate here that genetic changes specifically attributable to trisomy of Erg lead to lineage priming of primitive and early multipotential progenitor cells in Ts(1716)65Dn mice, excess megakaryocyte-erythroid progenitors, and malignant myeloproliferation. Gene expression changes dependent on trisomy of Erg in Ts(1716)65Dn multilineage progenitor cells were correlated with those associated with trisomy of HSA21 in human DS hematopoietic stem and primitive progenitor cells. These data suggest a role for ERG as a regulator of hematopoietic lineage potential, and that trisomy of ERG in the context of DS foetal liver hemopoiesis drives the pre-leukemic changes that predispose to subsequent DS-TMD and DS-AMKL. PMID:25973911

Thioredoxins in evolutionarily primitive organisms

NASA Technical Reports Server (NTRS)

Buchanan, B. B.

1986-01-01

Thioredoxins are low molecular weight redox proteins, alternating between the S-S (oxidized) and SH (reduced) states, that function in a number of biochemical processes, including DNA synthesis, DNA replication, and enzyme regulation. Until recently, reduced ferredoxin was known to serve as the source of reducing power for the reduction of thioredoxins only in oxygenic photosynthetic cells. In all other organisms, the source of hydrogen (electrons) for thioredoxin reduction was considered to be NADPH. It was found that Clostridium pasteurianum, an anaerobic organism normally living in the soil unexposed to light, resembles photosynthetic cells in using ferredoxin for the reduction of thioredoxin. The results reveal the existence of a pathway in which ferredoxin, provides the reducing power for the reduction of thioredoxin via the flavoprotein enzyme, ferredoxinthioredoxin reductase. In related studies, it was found that Chromatium vinosum, an anaerobic photosynthetic purple sulfur bacterium, resembles evolutionarily more advanced micro-organisms in having an NADP-thioredoxin system composed of a single thioredoxin which is reduced by NADPH via NADP-thioredoxin reductase. The adoption of the NADP-thioredoxin system by Chromatium seems appropriate in view of evidence tha the organi sm utilizes ATP-driven reverse electron transport. Finally, results of research directed towards the identification of target enzymes of the ferredoxin/thioredoxin system in a cyanobacterium (Nostoc muscorum), show that thioredoxin-linked photosynthetic enzymes of cyanobateria are similar to those of chloroplasts. It now seems that the ferredoxin/thioredoxin system functions in regulating CO2 assimilation via the reductive pentose phosphate cycle in oxygenic but not anoxygenic photosynthetic cells.

Along-strike variability of primitive magmas (major and volatile elements) inferred from olivine-hosted melt inclusions, southernmost Andean Southern Volcanic Zone, Chile

NASA Astrophysics Data System (ADS)

Weller, D. J.; Stern, C. R.

2018-01-01

Glass compositions of melt inclusions in olivine phenocrysts found in tephras derived from explosive eruptions of the four volcanoes along the volcanic front of the southernmost Andean Southern Volcanic Zone (SSVZ) are used to constrain primitive magma compositions and melt generation parameters. Primitive magmas from Hudson, Macá, and Melimoyu have similar compositions and are formed by low degrees (8-18%) of partial melting. Compared to these other three centers, primitive magmas from Mentolat have higher Al2O3 and lower MgO, TiO2 and other incompatible minor elements, and are generated by somewhat higher degrees (12-20%) of partial melting. The differences in the estimated primitive parental magma compositions between Mentolat and the other three volcanic centers are consistent with difference in the more evolved magmas erupted from these centers, Mentolat magmas having higher Al2O3 and lower MgO, TiO2 and other incompatible minor element contents, suggesting that these differences are controlled by melting processes in the mantle source region above the subducted oceanic plate. Parental magma S = 1430-594 and Cl = 777-125 (μg/g) contents of Hudson, Macá, and Melimoyu are similar to other volcanoes further north in the SVZ. However, Mentolat primitive magmas have notably higher concentrations of S = 2656-1227 and Cl = 1078-704 (μg/g). The observed along-arc changes in parental magma chemistry may be due to the close proximity below Mentolat of the subducted Guamblin Fracture Zone that could efficiently transport hydrous mineral phases, seawater, and sediment into the mantle, driving enhanced volatile fluxed melting beneath this center compared to the others. Table S2. Olivine-hosted melt inclusion compositions, host-olivine compositions, and the post-entrapment crystallization corrected melt inclusion compositions. Table S3. Olivine-hosted melt inclusion modeling information. Table S4. Major element compositions of the fractionation corrected melt inclusion in equilibrium with mantle olivine. Table S5. Melting parameters Fm and CoH2O. Table S6. Major element compositions of phenocrysts and glasses occurring with the olivine-hosted melt inclusions.

Melt Inclusions Record Extreme Compositional Variability in Primitive Magmas at Mauna Loa Volcano, Hawaii

NASA Astrophysics Data System (ADS)

Kamenetsky, V. S.; Norman, M. D.; Garcia, M. O.

2002-12-01

Melt inclusions carry potentially unique information about magmatic processes and the compositional evolution of erupted lavas. Major element compositions of olivine-hosted melt inclusions in submarine tholeiitic picrites from the southwest rift zone of Mauna Loa volcano have been studied to examine the compositional variability of primitive magmas feeding the world's largest volcano. Approximately 600 naturally quenched inclusions were examined from 8 samples with 3-25 vol% olivine phenocrysts and 9-22 wt% MgO. Olivine compositions ranged from Fo91-Fo82. The inclusions show a continuous variation in FeO contents from near-magmatic values (9 to 11 wt%) in the most evolved olivines to extremely low values (3.5 to 7.0 wt%) in the most primitive olivines. This appears to reflect a complex magmatic history for these crystals involving extensive re-equlibration of melts trapped by early formed phenocrysts with their host olivine. Extreme compositional variability also characterizes incompatible elements that would not be affected by equilibration with the host olivine. Inclusions trapped in relatively primitive olivines (Fo88-91) show a large range of K2O contents (0.1 to 2.1 wt%), whereas inclusions in more evolved olivines converge on whole rock compositions with 0.3 to 0.4 wt% K2O. Similarly, TiO2/K2O, Na2O/K2O, and K2O/P2O5 ratios of inclusions in primitive olivines span a much larger range than do inclusions hosted by more evolved olivines, with TiO2/K2O ratios extending from enriched to depleted compositions (1.2 to 24.7) in primitive olivines, and converging on whole rock compositions (TiO2/K2O = 6-9) in more evolved host olivine. This points toward extreme compositional variability in melts feeding Mauna Loa, and effective mixing of these melt parcels in the shallower summit reservoir to produce the restricted range of whole rock compositions sampled by erupted lavas. Whole rock compositions, therefore provide an integrated view of melting and high-level mixing processes, whereas melt inclusions provide more detailed information about source characteristics.

CIF2Cell: Generating geometries for electronic structure programs

NASA Astrophysics Data System (ADS)

Björkman, Torbjörn

2011-05-01

The CIF2Cell program generates the geometrical setup for a number of electronic structure programs based on the crystallographic information in a Crystallographic Information Framework (CIF) file. The program will retrieve the space group number, Wyckoff positions and crystallographic parameters, make a sensible choice for Bravais lattice vectors (primitive or principal cell) and generate all atomic positions. Supercells can be generated and alloys are handled gracefully. The code currently has output interfaces to the electronic structure programs ABINIT, CASTEP, CPMD, Crystal, Elk, Exciting, EMTO, Fleur, RSPt, Siesta and VASP. Program summaryProgram title: CIF2Cell Catalogue identifier: AEIM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL version 3 No. of lines in distributed program, including test data, etc.: 12 691 No. of bytes in distributed program, including test data, etc.: 74 933 Distribution format: tar.gz Programming language: Python (versions 2.4-2.7) Computer: Any computer that can run Python (versions 2.4-2.7) Operating system: Any operating system that can run Python (versions 2.4-2.7) Classification: 7.3, 7.8, 8 External routines: PyCIFRW [1] Nature of problem: Generate the geometrical setup of a crystallographic cell for a variety of electronic structure programs from data contained in a CIF file. Solution method: The CIF file is parsed using routines contained in the library PyCIFRW [1], and crystallographic as well as bibliographic information is extracted. The program then generates the principal cell from symmetry information, crystal parameters, space group number and Wyckoff sites. Reduction to a primitive cell is then performed, and the resulting cell is output to suitably named files along with documentation of the information source generated from any bibliographic information contained in the CIF file. If the space group symmetries is not present in the CIF file the program will fall back on internal tables, so only the minimal input of space group, crystal parameters and Wyckoff positions are required. Additional key features are handling of alloys and supercell generation. Additional comments: Currently implements support for the following general purpose electronic structure programs: ABINIT [2,3], CASTEP [4], CPMD [5], Crystal [6], Elk [7], exciting [8], EMTO [9], Fleur [10], RSPt [11], Siesta [12] and VASP [13-16]. Running time: The examples provided in the distribution take only seconds to run.

Stem cell transplantation (cord blood transplants).

PubMed

Chao, Nelson J; Emerson, Stephen G; Weinberg, Kenneth I

2004-01-01

Allogeneic stem cell transplantation is an accepted treatment modality for selected malignant and non-malignant diseases. However, the ability to identify suitably matched related or unrelated donors can be difficult in some patients. Alternative sources of stem cells such as cord blood provide a readily available graft for such patients. Data accumulated over the past several years have demonstrated that the use of cord blood is an accepted source of stem cells for pediatric patients. Since the cell numbers of hematopoietic progenitors in cord blood is limited and the collection can occur only in a single occasion, its use in adult patients can be more problematic. Here, new developments in the use of cord blood for adults and studies aimed at expansion of cord blood cells and immune reconstitution are described. In Section I, Dr. Nelson Chao describes the early data in cord blood transplantation in adult patients. The patient outcomes are reviewed and analyzed for various factors such as cell dose, HLA typing, and patient selection that could have contributed to the final outcome of these adult patients. Myeloablative as well as nonmyeloablative approaches are presented. Discussion of the various benefits and risks are presented. More recent data from multiple single institutions as well as larger registry data comparisons are also provided. Analyses of these studies suggest methods to improve on the outcome. These newer data should lead to a logical progression in the use of cord blood cells in adult patients. In Section II, Dr. Stephen Emerson describes the historical efforts associated with expansion of hematopoietic stem cells, specifically with cord blood cells. These efforts to expand cord blood cells continue with novel methods. Moreover, a better understanding of stem cell biology and signaling is critical if we are to be able to effectively expand these cells for clinical use. An alternative, more direct, approach to expanding stem cells could be achieved by specific genetic pathways known or believed to support primitive HSC proliferation such as Notch-1 receptor activation, Wnt/LEF-1 pathway induction, telomerase or the Homeobox (Hox) gene products. The clinical experience with the use of expanded cord blood cells is also discussed. In Section III, Dr. Kenneth Weinberg describes immune reconstitution or lack thereof following cord blood transplantation. One of the hallmarks of successful hematopoietic stem cell transplantation is the ability to fully reconstitute the immune system of the recipient. Thus, the relationship between stem cell source and the development of T lymphocyte functions required for protection of the recipient from infection will be described, and cord blood recipients will be compared with those receiving other sources of stem cells. T cell development is described in detail, tracking from prethymic to postthymic lymphocytes with specific attention to umbilical cord blood as the source of stem cells. Moreover, a discussion of the placenta as a special microenvironment for umbilical cord blood is presented. Strategies to overcome the immunological defects are presented to improve the outcome of these recipients.

17-N-Allylamino-17-Demethoxygeldanamycin in Treating Patients With Advanced Epithelial Cancer, Malignant Lymphoma, or Sarcoma

ClinicalTrials.gov

2013-02-06

AIDS-related Peripheral/Systemic Lymphoma; AIDS-related Primary CNS Lymphoma; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-cell Lymphoma; Chondrosarcoma; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Intraocular Lymphoma; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Osteosarcoma; Nodal Marginal Zone B-cell Lymphoma; Ovarian Sarcoma; Primary Central Nervous System Non-Hodgkin Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult Soft Tissue Sarcoma; Recurrent Adult T-cell Leukemia/Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Osteosarcoma; Recurrent Small Lymphocytic Lymphoma; Recurrent Uterine Sarcoma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage IV Adult Burkitt Lymphoma; Stage IV Adult Diffuse Large Cell Lymphoma; Stage IV Adult Diffuse Mixed Cell Lymphoma; Stage IV Adult Diffuse Small Cleaved Cell Lymphoma; Stage IV Adult Hodgkin Lymphoma; Stage IV Adult Immunoblastic Large Cell Lymphoma; Stage IV Adult Lymphoblastic Lymphoma; Stage IV Adult Soft Tissue Sarcoma; Stage IV Adult T-cell Leukemia/Lymphoma; Stage IV Cutaneous T-cell Non-Hodgkin Lymphoma; Stage IV Grade 1 Follicular Lymphoma; Stage IV Grade 2 Follicular Lymphoma; Stage IV Grade 3 Follicular Lymphoma; Stage IV Mantle Cell Lymphoma; Stage IV Marginal Zone Lymphoma; Stage IV Mycosis Fungoides/Sezary Syndrome; Stage IV Small Lymphocytic Lymphoma; Stage IV Uterine Sarcoma; Unspecified Adult Solid Tumor, Protocol Specific

Shape-Shifted Red Blood Cells: A Novel Red Blood Cell Stage?

PubMed Central

Chico, Verónica; Puente-Marin, Sara; Ciordia, Sergio; Mena, María Carmen; Carracedo, Begoña; Mercado, Luis; Coll, Julio

2018-01-01

Primitive nucleated erythroid cells in the bloodstream have long been suggested to be more similar to nucleated red cells of fish, amphibians, and birds than the red cells of fetal and adult mammals. Rainbow trout Ficoll-purified red blood cells (RBCs) cultured in vitro undergo morphological changes, especially when exposed to stress, and enter a new cell stage that we have coined shape-shifted RBCs (shRBCs). We have characterized these shRBCs using transmission electron microscopy (TEM) micrographs, Wright–Giemsa staining, cell marker immunostaining, and transcriptomic and proteomic evaluation. shRBCs showed reduced density of the cytoplasm, hemoglobin loss, decondensed chromatin in the nucleus, and striking expression of the B lymphocyte molecular marker IgM. In addition, shRBCs shared some features of mammalian primitive pyrenocytes (extruded nucleus surrounded by a thin rim of cytoplasm and phosphatidylserine (PS) exposure on cell surface). These shRBCs were transiently observed in heat-stressed rainbow trout bloodstream for three days. Functional network analysis of combined transcriptomic and proteomic studies resulted in the identification of proteins involved in pathways related to the regulation of cell morphogenesis involved in differentiation, cellular response to stress, and immune system process. In addition, shRBCs increased interleukin 8 (IL8), interleukin 1 β (IL1β), interferon ɣ (IFNɣ), and natural killer enhancing factor (NKEF) protein production in response to viral hemorrhagic septicemia virus (VHSV). In conclusion, shRBCs may represent a novel cell stage that participates in roles related to immune response mediation, homeostasis, and the differentiation and development of blood cells. PMID:29671811

Shape-Shifted Red Blood Cells: A Novel Red Blood Cell Stage?

PubMed

Chico, Verónica; Puente-Marin, Sara; Nombela, Iván; Ciordia, Sergio; Mena, María Carmen; Carracedo, Begoña; Villena, Alberto; Mercado, Luis; Coll, Julio; Ortega-Villaizan, María Del Mar

2018-04-19

Primitive nucleated erythroid cells in the bloodstream have long been suggested to be more similar to nucleated red cells of fish, amphibians, and birds than the red cells of fetal and adult mammals. Rainbow trout Ficoll-purified red blood cells (RBCs) cultured in vitro undergo morphological changes, especially when exposed to stress, and enter a new cell stage that we have coined shape-shifted RBCs (shRBCs). We have characterized these shRBCs using transmission electron microscopy (TEM) micrographs, Wright⁻Giemsa staining, cell marker immunostaining, and transcriptomic and proteomic evaluation. shRBCs showed reduced density of the cytoplasm, hemoglobin loss, decondensed chromatin in the nucleus, and striking expression of the B lymphocyte molecular marker IgM. In addition, shRBCs shared some features of mammalian primitive pyrenocytes (extruded nucleus surrounded by a thin rim of cytoplasm and phosphatidylserine (PS) exposure on cell surface). These shRBCs were transiently observed in heat-stressed rainbow trout bloodstream for three days. Functional network analysis of combined transcriptomic and proteomic studies resulted in the identification of proteins involved in pathways related to the regulation of cell morphogenesis involved in differentiation, cellular response to stress, and immune system process. In addition, shRBCs increased interleukin 8 (IL8), interleukin 1 β (IL1β), interferon ɣ (IFNɣ), and natural killer enhancing factor (NKEF) protein production in response to viral hemorrhagic septicemia virus (VHSV). In conclusion, shRBCs may represent a novel cell stage that participates in roles related to immune response mediation, homeostasis, and the differentiation and development of blood cells.

Insights into the evolution of an alkaline magmatic system: An in situ trace element study of clinopyroxenes from the Ditrău Alkaline Massif, Romania

NASA Astrophysics Data System (ADS)

Batki, Anikó; Pál-Molnár, Elemér; Jankovics, M. Éva; Kerr, Andrew C.; Kiss, Balázs; Markl, Gregor; Heincz, Adrián; Harangi, Szabolcs

2018-02-01

Clinopyroxene is a major constituent in most igneous rock types (hornblendite, diorite, syenite, nepheline syenite, camptonite, tinguaite and ijolite) of the Ditrău Alkaline Massif, Eastern Carpathians, Romania. Phenocryst and antecryst populations have been distinguished based on mineral zoning patterns and geochemical characteristics. Major and trace element compositions of clinopyroxenes reflect three dominant pyroxene types including primitive high-Cr Fe-diopside, intermediate Na-diopside-hedenbergite and evolved high-Zr aegirine-augite. Clinopyroxenes record two major magma sources as well as distinct magma evolution trends. The primitive diopside population is derived from an early camptonitic magma related to basanitic parental melts, whilst the intermediate diopside-hedenbergite crystals represent a Na-, Nb- and Zr-rich magma source recognised for the first time in the Ditrău magmatic system. This magma fractionated towards ijolitic and later phonolitic compositions. Field observations, petrography and clinopyroxene-melt equilibrium calculations reveal magma recharge and mingling, pyroxene recycling, fractional crystallisation and accumulation. Repeated recharge events of the two principal magmas resulted in multiple interactions between more primitive and more fractionated co-existing magma batches. Magma mingling occurred between mafic and felsic magmas by injection of ijolitic magma into fissures (dykes) containing phonolitic (tinguaite) magma. This study shows that antecryst recycling, also described for the first time in Ditrău, is a significant process during magma recharge and demonstrates that incorporated crystals can crucially affect the host magma composition and so whole-rock chemical data should be interpreted with great care.

The record of mantle heterogeneity preserved in Earth's oceanic crust

NASA Astrophysics Data System (ADS)

Burton, K. W.; Parkinson, I. J.; Schiano, P.; Gannoun, A.; Laubier, M.

2017-12-01

Earth's oceanic crust is produced by melting of the upper mantle where it upwells beneath mid-ocean ridges, and provides a geographically widespread elemental and isotopic `sample' of Earth's mantle. The chemistry of mid-ocean ridge basalts (MORB), therefore, holds key information on the compositional diversity of the upper mantle, but the problem remains that mixing and reaction during melt ascent acts to homogenise the chemical variations they acquire. Nearly all isotope and elemental data obtained thus far are for measurements of MORB glass, and this represents the final melt to crystallise, evolving in an open system. However, the crystals that are present are often not in equilibrium with their glass host. Melts trapped in these minerals indicate that they crystallised from primitive magmas that possess diverse compositions compared to the glass. Therefore, these melt inclusions preserve information on the true extent of the mantle that sources MORB, but are rarely amenable to precise isotope measurement. An alternative approach is to measure the isotope composition of the primitive minerals themselves. Our new isotope data indicates that these minerals crystallised from melts with significantly different isotope compositions to their glass host, pointing to a mantle source that has experienced extreme melt depletion. These primitive minerals largely crystallised in the lower oceanic crust, and our preliminary data for lower crustal rocks and minerals shows that they preserve a remarkable range of isotope compositions. Taken together, these results indicate that the upper mantle sampled by MORB is extremely heterogeneous, reflecting depletion and enrichment over much of Earth's geological history.

Propagation of eigenmodes and transfer functions in waveguide WDM structures

NASA Astrophysics Data System (ADS)

Mashkov, Vladimir A.; Francoeur, S.; Geuss, U.; Neiser, K.; Temkin, Henryk

1998-02-01

A method of propagation functions and transfer amplitudes suitable for the design of integrated optical circuits is presented. The method is based on vectorial formulation of electrodynamics: the distributions and propagation of electromagnetic fields in optical circuits is described by equivalent surface sources. This approach permits a division of complex optical waveguide structures into sets of primitive blocks and to separately calculate the transfer function and the transfer amplitude for each block. The transfer amplitude of the entire optical system is represented by a convolution of transfer amplitudes of its primitive blocks. The eigenvalues and eigenfunctions of arbitrary waveguide structure are obtained in the WKB approximation and compared with other methods. The general approach is illustrated with the transfer amplitude calculations for Dragone's star coupler and router.

Novel Target for Ameliorating Pain and Other Problems after SCI: Spontaneous Activity in Nociceptors

DTIC Science & Technology

2016-06-01

BSCB will permit blood-borne mye- loid and lymphoid immune cells to enter the spinal cord parenchyma and exert direct inflammatory actions on central...primitive innate immune system is the first line of defense against pathogens and toxins; it is always present and it depends upon diverse cell types that...adaptive immune system, the innate immune system does not em- ploy antigen-specific humoral and cell -mediated immunity mecha- nisms. Two innate immune

Using Depth Recovery in Humans

DTIC Science & Technology

1988-07-07

presence of oriented luminance discontinuities or "edges" in the image data (Marr & Poggio, i976; Dey, 1975; Nelson, 1975 & 1977; Marr, Palm & Poggio, 1978...primitives, namely computational expense, is rapidly diminishing as we continue to benefit from dramatic advances in signal processing hardware...dimensional weighting function of simple cells are well fitted by Gabor functions. Pollen & Ronner (1981) demonstrated that simple cells which are tuned to

The molecular characterization of porcine egg precursor cells

PubMed Central

Tsai, Te-Sha; Johnson, Jacqueline; White, Yvonne; John, Justin C.

2017-01-01

Female-factor infertility can be caused by poor oocyte quality and depleted ovarian reserves. Egg precursor cells (EPCs), isolated from the ovarian cortex, have the potential to be used to overcome female infertility. We aimed to define the origins of EPCs by analyzing their gene expression profiles and mtDNA content using a mini-pig model. We characterized FAC-sorted DDX4+-derived porcine EPCs by performing RNA-sequencing and determined that they utilize pathways important for cell cycle and proliferation, which supports the existence of adult mitotically active oogonial cells. Expression of the pluripotent markers Sox2 and Oct4, and the primitive germ cell markers Blimp1 and Stella were not detected. However, Nanog and Ddx4 were expressed, as were the primitive germ cell markers Fragilis, c-Kit and Tert. Moreover, porcine EPCs expressed self-renewal and proliferation markers including Myc, Esrrb, Id2, Klf4, Klf5, Stat3, Fgfr1, Fgfr2 and Il6st. The presence of Zp1, Zp2, Zp3 and Nobox were not detected, indicating that porcine EPCs are not indicative of mature primordial oocytes. We performed mitochondrial DNA Next Generation Sequencing and determined that one mtDNA variant harbored by EPCs was present in oocytes, preimplantation embryos and somatic tissues over three generations in our mini-pig model indicating the potential germline origin of EPCs. PMID:28969006

Primitive neuroectodermal tumor of the cervix uteri. A case report.

PubMed

Horn, L C; Fischer, U; Bilek, K

1997-02-01

Primitive neuroectodermal tumors (PNET) of the female genital tract are rare and more common in the ovary, but uncommon in the cervix uteri. A 26-year-old woman presented with suspect cervical smears. The conization specimen showed a small cell non-keratinised squamous cell carcinoma with involved margins. The patient underwent radical abdominal hysterectomy and pelvic lymphonodectomy. The microscopic examination showed a densely cellular tumor of small neuroendocrine cells with scanty cytoplasm and rosettes. Immunohistochemically, the cells were slightly positive for NSE and negative for S 100, GFAP, neurofilaments, squamous cell cytokeratin 1, vimentin, desmin and leukocyte common antigen. The diagnosis of PNET, stage pT1b1,N0, M0 was made. The patient underwent adjuvant pelvic radiation. Three years later, pulmonary metastases occured. Radiation therapy of the thorax and six courses of combination chemotherapy (5-FU and cis-platinium) could not prevent tumor progression. The patient died 4.2 years after diagnosis. The autopsy showed widespread lymphatic metastases and hepatic, pulmonal and skeletal metastases and a peritoneal carcinosis. The tumors are resistent to radio- and chemotherapy, and the prognosis is generally poor. Up to 15% foci of squamous or glandular differentiation occur in or adjacent to these tumors. So the authors favor the histogenesis from a pluripotent endocervical stem cell. The neuroendocrine component of mixed tumors improve the prognosis. Therefore, it is necessary to recognize this component.

DNase I hypersensitivity and epsilon-globin transcriptional enhancement are separable in locus control region (LCR) HS1 mutant human beta-globin YAC transgenic mice.

PubMed

Shimotsuma, Motoshi; Okamura, Eiichi; Matsuzaki, Hitomi; Fukamizu, Akiyoshi; Tanimoto, Keiji

2010-05-07

Expression of the five beta-like globin genes (epsilon, Ggamma, Agamma, delta, beta) in the human beta-globin locus depends on enhancement by the locus control region, which consists of five DNase I hypersensitive sites (5'HS1 through 5'HS5). We report here a novel enhancer activity in 5'HS1 that appears to be potent in transfected K562 cells. Deletion analyses identified a core activating element that bound to GATA-1, and a two-nucleotide mutation that disrupted GATA-1 binding in vitro abrogated 5'HS1 enhancer activity in transfection experiments. To determine the in vivo role of this GATA site, we generated multiple lines of human beta-globin YAC transgenic mice bearing the same two-nucleotide mutation. In the mutant mice, epsilon-, but not gamma-globin, gene expression in primitive erythroid cells was severely attenuated, while adult beta-globin gene expression in definitive erythroid cells was unaffected. Interestingly, DNaseI hypersensitivity near the 5'HS1 mutant sequence was eliminated in definitive erythroid cells, whereas it was only mildly affected in primitive erythroid cells. We therefore conclude that, although the GATA site in 5'HS1 is critical for efficient epsilon-globin gene expression, hypersensitive site formation per se is independent of 5'HS1 function, if any, in definitive erythroid cells.

Efficacy of 68Ga-DOTATOC Positron Emission Tomography (PET) CT in Children and Young Adults With Brain Tumors

ClinicalTrials.gov

2017-04-27

Acoustic Schwannoma; Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Meningioma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Choroid Plexus Tumor; Adult Craniopharyngioma; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Medulloblastoma; Adult Meningeal Hemangiopericytoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Papillary Meningioma; Adult Pilocytic Astrocytoma; Adult Pineal Gland Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Subependymal Giant Cell Astrocytoma; Adult Subependymoma; Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebellar Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Childhood Supratentorial Ependymoma; Meningeal Melanocytoma; Newly Diagnosed Childhood Ependymoma; Recurrent Adult Brain Tumor; Recurrent Childhood Anaplastic Astrocytoma; Recurrent Childhood Anaplastic Oligoastrocytoma; Recurrent Childhood Anaplastic Oligodendroglioma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Diffuse Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Fibrillary Astrocytoma; Recurrent Childhood Gemistocytic Astrocytoma; Recurrent Childhood Giant Cell Glioblastoma; Recurrent Childhood Glioblastoma; Recurrent Childhood Gliomatosis Cerebri; Recurrent Childhood Gliosarcoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Oligoastrocytoma; Recurrent Childhood Oligodendroglioma; Recurrent Childhood Pilocytic Astrocytoma; Recurrent Childhood Pilomyxoid Astrocytoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Pleomorphic Xanthoastrocytoma; Recurrent Childhood Protoplasmic Astrocytoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Untreated Childhood Anaplastic Astrocytoma; Untreated Childhood Anaplastic Oligodendroglioma; Untreated Childhood Brain Stem Glioma; Untreated Childhood Cerebellar Astrocytoma; Untreated Childhood Cerebral Astrocytoma; Untreated Childhood Diffuse Astrocytoma; Untreated Childhood Fibrillary Astrocytoma; Untreated Childhood Gemistocytic Astrocytoma; Untreated Childhood Giant Cell Glioblastoma; Untreated Childhood Glioblastoma; Untreated Childhood Gliomatosis Cerebri; Untreated Childhood Gliosarcoma; Untreated Childhood Medulloblastoma; Untreated Childhood Oligoastrocytoma; Untreated Childhood Oligodendroglioma; Untreated Childhood Pilocytic Astrocytoma; Untreated Childhood Pilomyxoid Astrocytoma; Untreated Childhood Pineoblastoma; Untreated Childhood Pleomorphic Xanthoastrocytoma; Untreated Childhood Protoplasmic Astrocytoma; Untreated Childhood Subependymal Giant Cell Astrocytoma; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor; Untreated Childhood Visual Pathway and Hypothalamic Glioma; Untreated Childhood Visual Pathway Glioma

Niche displacement of human leukemic stem cells uniquely allows their competitive replacement with healthy HSPCs

PubMed Central

Boyd, Allison L.; Campbell, Clinton J.V.; Hopkins, Claudia I.; Fiebig-Comyn, Aline; Russell, Jennifer; Ulemek, Jelena; Foley, Ronan; Leber, Brian; Xenocostas, Anargyros; Collins, Tony J.

2014-01-01

Allogeneic hematopoietic stem cell (HSC) transplantation (HSCT) is currently the leading strategy to manage acute myeloid leukemia (AML). However, treatment-related morbidity limits the patient generalizability of HSCT use, and the survival of leukemic stem cells (LSCs) within protective areas of the bone marrow (BM) continues to lead to high relapse rates. Despite growing appreciation for the significance of the LSC microenvironment, it has remained unresolved whether LSCs preferentially situate within normal HSC niches or whether their niche requirements are more promiscuous. Here, we provide functional evidence that the spatial localization of phenotypically primitive human AML cells is restricted to niche elements shared with their normal counterparts, and that their intrinsic ability to initiate and retain occupancy of these niches can be rivaled by healthy hematopoietic stem and progenitor cells (HSPCs). When challenged in competitive BM repopulation assays, primary human leukemia-initiating cells (L-ICs) can be consistently outperformed by HSPCs for BM niche occupancy in a cell dose-dependent manner that ultimately compromises long-term L-IC renewal and subsequent leukemia-initiating capacity. The effectiveness of this approach could be demonstrated using cytokine-induced mobilization of established leukemia from the BM that facilitated the replacement of BM niches with transplanted HSPCs. These findings identify a functional vulnerability of primitive leukemia cells, and suggest that clinical development of these novel transplantation techniques should focus on the dissociation of L-IC–niche interactions to improve competitive replacement with healthy HSPCs during HSCT toward increased survival of patients. PMID:25180064

An immunohistochemical study of neuropeptides and neuronal cytoskeletal proteins in the neuroepithelial component of a spontaneous murine ovarian teratoma. Primitive neuroepithelium displays immunoreactivity for neuropeptides and neuron-associated beta-tubulin isotype.

PubMed Central

Caccamo, D. V.; Herman, M. M.; Frankfurter, A.; Katsetos, C. D.; Collins, V. P.; Rubinstein, L. J.

1989-01-01

Approximately one third of the female mice of the LTXBO strain develop spontaneous ovarian teratomas. These tumors contain a large neuroepithelial component, which includes primitive neural structures resembling embryonic neural tubes (medulloepithelial rosettes), ependymoblastic and ependymal rosettes, neuroblasts, mature ganglionic neurons, myelinated neurites, and astrocytes. The purpose of this study was to characterize these tumors according to the immunohistochemical location of some well-characterized trophic and regulatory neuropeptides and neurotransmitters, several neuronal-associated cytoskeletal proteins, and other proteins indicative of neuronal and glial differentiation. Medulloepithelial rosettes showed focal serotonin-like, opioid peptide-like and gamma-amino butyric acid-like immunoreactivity, and displayed immunostaining for the neuron-associated class III beta-tubulin isotype. The mature ganglion cells were also immunoreactive for these markers, and, in addition, for somatostatin, cholecystokinin, bombesin, glucagon, vasoactive intestinal peptide, and neuropeptide Y. Mature ganglion cells were also immunoreactive for proteins associated with the neuronal cytoskeleton (including microtubule-associated proteins, MAP2 and tau, and higher molecular weight phosphorylated and non-phosphorylated neurofilament subunits), neuron-specific enolase, and synaptophysin. Undifferentiated stem cells, ependymoblastic and ependymal rosettes, and astroglia all stained with a monoclonal antibody that recognizes all mammalian beta-tubulin isotypes, but did not react with antibodies to neuronal-associated cytoskeletal proteins or neuropeptides. Neuropeptide-like immunoreactivity and demonstration of the class III beta-tubulin isotype indicate early neuronal commitment in neoplastic primitive neuroepithelium. These patterns of immunoreactivity closely follow those encountered in the normal neurocytogenesis of the mammalian and avian forebrain, and increase the precision with which the early stages of progressive neuroepithelial differentiation can be analyzed in human embryonal tumors of the CNS. Images Figure 1 Figure 2 Figure 3 PMID:2817080

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles.

PubMed

Alibardi, L; Gill, B J

2007-07-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25-30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting.

Epidermal differentiation in embryos of the tuatara Sphenodon punctatus (Reptilia, Sphenodontidae) in comparison with the epidermis of other reptiles

PubMed Central

Alibardi, L; Gill, B J

2007-01-01

Studying the epidermis in primitive reptiles can provide clues regarding evolution of the epidermis during land adaptation in vertebrates. With this aim, the development of the skin of the relatively primitive reptile Sphenodon punctatus in representative embryonic stages was studied by light and electron microscopy and compared with that of other reptiles previously studied. The dermis organizes into a superficial and deep portion when the epidermis starts to form the first layers. At embryonic stages comparable with those of lizards, only one layer of the inner periderm is formed beneath the outer periderm. This also occurs in lizards and snakes so far studied. The outer and inner periderm form the embryonic epidermis and accumulate thick, coarse filaments (25–30 nm thick) and sparse alpha-keratin filaments as in other reptiles. Beneath the embryonic epidermis an oberhautchen and beta-cells form small horny tips that represent overlapping borders along the margin of beta-cells that overlap other beta-cells (in a tile-like arrangement). The tips resemble those of agamine lizards but at a small scale, forming a lamellate-spinulated pattern as previously described in adult epidermis. The embryonic epidermis matures by the dispersion of coarse filaments among keratin at the end of embryonic development and is shed around hatching. The presence of these matrix organelles in the embryonic epidermis of this primitive reptile further indicates that amniote epidermis acquired interkeratin matrix proteins early for land adaptation. Unlike the condition in lizards and snakes, a shedding complex is not formed in the epidermis of embryonic S. punctatus that is like that of the adult. Therefore, as in chelonians and crocodilians, the epidermis of S. punctatus also represents an initial stage that preceded the evolution of the shedding complex for moulting. PMID:17532799

Gluconeogenesis: An ancient biochemical pathway with a new twist

PubMed Central

Miyamoto, Tetsuya; Amrein, Hubert

2017-01-01

ABSTRACT Synthesis of sugars from simple carbon sources is critical for survival of animals under limited nutrient availability. Thus, sugar-synthesizing enzymes should be present across the entire metazoan spectrum. Here, we explore the evolution of glucose and trehalose synthesis using a phylogenetic analysis of enzymes specific for the two pathways. Our analysis reveals that the production of trehalose is the more ancestral biochemical process, found in single cell organisms and primitive metazoans, but also in insects. The gluconeogenic-specific enzyme glucose-6-phosphatase (G6Pase) first appears in Cnidaria, but is also present in Echinodermata, Mollusca and Vertebrata. Intriguingly, some species of nematodes and arthropods possess the genes for both pathways. Moreover, expression data from Drosophila suggests that G6Pase and, hence, gluconeogenesis, initially had a neuronal function. We speculate that in insects—and possibly in some vertebrates—gluconeogenesis may be used as a means of neuronal signaling. PMID:28121487

Optimization of chemical displacement deposition of copper on porous silicon.

PubMed

Bandarenka, Hanna; Redko, Sergey; Nenzi, Paolo; Balucani, Marco; Bondarenko, Vitaly

2012-11-01

Copper (II) sulfate was used as a source of copper to achieve uniform distribution of Cu particles deposited on porous silicon. Layers of the porous silicon were formed by electrochemical anodization of Si wafers in a mixture of HF, C3H7OH and deionized water. The well-known chemical displacement technique was modified to grow the copper particles of specific sizes. SEM and XRD analysis revealed that the outer surface of the porous silicon was covered with copper particles of the crystal orientation inherited from the planes of porous silicon skeleton. The copper crystals were found to have the cubic face centering elementary cell. In addition, the traces of Cu2O cubic primitive crystalline phases were identified. The dimensions of Cu particles were determined by the Feret's analysis of the SEM images. The sizes of the particles varied widely from a few to hundreds of nanometers. A phenomenological model of copper deposition was proposed.

Crystallization and preliminary X-ray analysis of CTP:phosphoethanolamine cytidylyltransferase (ECT) from Saccharomyces cerevisiae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohtsuka, Jun; Nagata, Koji; Lee, Woo Cheol

2006-10-01

CTP:phosphoethanolamine cytidylyltransferase from S. cerevisiae has been expressed, purified and crystallized. CTP:phosphoethanolamine cytidylyltransferase (ECT) is the enzyme that catalyzes the conversion of phosphoethanolamine to CDP-ethanolamine in the phosphatidylethanolamine-biosynthetic pathway (Kennedy pathway). ECT from Saccharomyces cerevisiae was crystallized by the sitting-drop vapour-diffusion method using PEG 4000 as precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.88 Å resolution. The space group was assigned as primitive tetragonal, P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = b = 66.3, c = 150.8 Å. The crystals contain one ECT molecule in the asymmetric unit (V{sub M} = 2.2more » Å{sup 3} Da{sup −1}), with a solvent content of 43%.« less

Gluconeogenesis: An ancient biochemical pathway with a new twist.

PubMed

Miyamoto, Tetsuya; Amrein, Hubert

2017-07-03

Synthesis of sugars from simple carbon sources is critical for survival of animals under limited nutrient availability. Thus, sugar-synthesizing enzymes should be present across the entire metazoan spectrum. Here, we explore the evolution of glucose and trehalose synthesis using a phylogenetic analysis of enzymes specific for the two pathways. Our analysis reveals that the production of trehalose is the more ancestral biochemical process, found in single cell organisms and primitive metazoans, but also in insects. The gluconeogenic-specific enzyme glucose-6-phosphatase (G6Pase) first appears in Cnidaria, but is also present in Echinodermata, Mollusca and Vertebrata. Intriguingly, some species of nematodes and arthropods possess the genes for both pathways. Moreover, expression data from Drosophila suggests that G6Pase and, hence, gluconeogenesis, initially had a neuronal function. We speculate that in insects-and possibly in some vertebrates-gluconeogenesis may be used as a means of neuronal signaling.

Secure Heterogeneous Multicore Platform Through Diversity and Redundancy

DTIC Science & Technology

2012-03-31

implementation detects synchronization in this way. If a programmer uses custom synchronization primitives , our approach assumes that such primitives ... synchronization primitives . Primitives such as barriers and spinlocks explicitly enforce a pre- determined ordering among threads. Therefore, the outcome of...these synchronization operations are deterministic. In the discussion, we will refer to these primitives as ordering synchronization operations. On the

HOXB4 overexpression mediates very rapid stem cell regeneration and competitive hematopoietic repopulation.

PubMed

Antonchuk, J; Sauvageau, G; Humphries, R K

2001-09-01

Hox transcription factors have emerged as important regulators of hematopoiesis. In particular, we have shown that overexpression of HOXB4 in mouse bone marrow can greatly enhance the level of hematopoietic stem cell (HSC) regeneration achieved at late times (> 4 months) posttransplantation. The objective of this study was to resolve if HOXB4 increases the rate and/or duration of HSC regeneration, and also to see if this enhancement was associated with impaired production of end cells or would lead to competitive reconstitution of all compartments. Retroviral vectors were generated with the GFP reporter gene +/- HOXB4 to enable the isolation and direct tracking of transduced cells in culture or following transplantation. Stem cell recovery was measured by limit dilution assay for long-term competitive repopulating cells (CRU). HOXB4-overexpressing cells have enhanced growth in vitro, as demonstrated by their rapid dominance in mixed cultures and their shortened population doubling time. Furthermore, HOXB4-transduced cells have a marked competitive repopulating advantage in vivo in both primitive and mature compartments. CRU recovery in HOXB4 recipients was extremely rapid, reaching 25% of normal by 14 days posttransplant or some 80-fold greater than control transplant recipients, and attaining normal numbers by 12 weeks. Mice transplanted with even higher numbers of HOXB4-transduced CRU regenerated up to but not beyond the normal CRU levels. HOXB4 is a potent enhancer of primitive hematopoietic cell growth, likely by increasing self-renewal probability but without impairing homeostatic control of HSC population size or the rate of production and maintenance of mature end cells.

Stereotactic Radiosurgery in Treating Patients With Brain Tumors

ClinicalTrials.gov

2012-03-21

Adult Central Nervous System Germ Cell Tumor; Adult Malignant Meningioma; Adult Medulloblastoma; Adult Noninfiltrating Astrocytoma; Adult Oligodendroglioma; Adult Craniopharyngioma; Adult Meningioma; Brain Metastases; Adult Ependymoma; Adult Pineal Parenchymal Tumor; Adult Brain Stem Glioma; Adult Infiltrating Astrocytoma; Mixed Gliomas; Stage IV Peripheral Primitive Neuroectodermal Tumor

Non-canonical Wnt signalling modulates the endothelial shear stress flow sensor in vascular remodelling

PubMed Central

Franco, Claudio A; Jones, Martin L; Bernabeu, Miguel O; Vion, Anne-Clemence; Barbacena, Pedro; Fan, Jieqing; Mathivet, Thomas; Fonseca, Catarina G; Ragab, Anan; Yamaguchi, Terry P; Coveney, Peter V; Lang, Richard A; Gerhardt, Holger

2016-01-01

Endothelial cells respond to molecular and physical forces in development and vascular homeostasis. Deregulation of endothelial responses to flow-induced shear is believed to contribute to many aspects of cardiovascular diseases including atherosclerosis. However, how molecular signals and shear-mediated physical forces integrate to regulate vascular patterning is poorly understood. Here we show that endothelial non-canonical Wnt signalling regulates endothelial sensitivity to shear forces. Loss of Wnt5a/Wnt11 renders endothelial cells more sensitive to shear, resulting in axial polarization and migration against flow at lower shear levels. Integration of flow modelling and polarity analysis in entire vascular networks demonstrates that polarization against flow is achieved differentially in artery, vein, capillaries and the primitive sprouting front. Collectively our data suggest that non-canonical Wnt signalling stabilizes forming vascular networks by reducing endothelial shear sensitivity, thus keeping vessels open under low flow conditions that prevail in the primitive plexus. DOI: http://dx.doi.org/10.7554/eLife.07727.001 PMID:26845523

Principles determining the structure of high-pressure forms of metals: The structures of cesium(IV) and cesium(V)

PubMed Central

Pauling, Linus

1989-01-01

Consideration of the relation between bond length and bond number and the average atomic volume for different ways of packing atoms leads to the conclusion that the average ligancy of atoms in a metal should increase when a phase change occurs on increasing the pressure. Minimum volume for each value of the ligancy results from triangular coordination polyhedra (with triangular faces), such as the icosahedron and the Friauf polyhedron. Electron transfer may permit atoms of an element to assume different ligancies. Application of these principles to Cs(IV) and Cs(V), which were previously assigned structures with ligancy 8 and 6, respectively, has led to the assignment to Cs(IV) of a primitive cubic unit cell with a = 16.11 Å and with about 122 atoms in the cube and to Cs(V) of a primitive cubic unit cell resembling that of Mg32(Al,Zn)49, with a = 16.97 Å and with 162 atoms in the cube. PMID:16578839

A network of epigenetic regulators guides developmental haematopoiesis in vivo.

PubMed

Huang, Hsuan-Ting; Kathrein, Katie L; Barton, Abby; Gitlin, Zachary; Huang, Yue-Hua; Ward, Thomas P; Hofmann, Oliver; Dibiase, Anthony; Song, Anhua; Tyekucheva, Svitlana; Hide, Winston; Zhou, Yi; Zon, Leonard I

2013-12-01

The initiation of cellular programs is orchestrated by key transcription factors and chromatin regulators that activate or inhibit target gene expression. To generate a compendium of chromatin factors that establish the epigenetic code during developmental haematopoiesis, a large-scale reverse genetic screen was conducted targeting orthologues of 425 human chromatin factors in zebrafish. A set of chromatin regulators was identified that target different stages of primitive and definitive blood formation, including factors not previously implicated in haematopoiesis. We identified 15 factors that regulate development of primitive erythroid progenitors and 29 factors that regulate development of definitive haematopoietic stem and progenitor cells. These chromatin factors are associated with SWI/SNF and ISWI chromatin remodelling, SET1 methyltransferase, CBP-p300-HBO1-NuA4 acetyltransferase, HDAC-NuRD deacetylase, and Polycomb repressive complexes. Our work provides a comprehensive view of how specific chromatin factors and their associated complexes play a major role in the establishment of haematopoietic cells in vivo.

A Chill Sequence to the Bushveld Complex - Insight into the First Stages of Emplacement and the Parental Magmas to the World's Largest Layered Intrusion

NASA Astrophysics Data System (ADS)

Wilson, A.

2012-04-01

Evidence of the initial stages of magma emplacement in large mafic chambers is commonly lacking because of resorption of early-formed chills and complicated by the fact that the first magmas that entered the chamber were usually more evolved than the true parental magma. Deep drilling has revealed a rare occurrence of a chill sequence from the eastern Bushveld Complex at the base of a previously unrecognized thick succession of ultramafic rocks that forms part of the Lower Zone. The chill sequence (1.8 m thick) includes a true chill against quartzite floor rock, crystalline quench textured and orthopyroxene spinifex textured rocks. Importantly the chill composition represents a relatively evolved magma formed by the separation of high-Mg olivines prior to its emplacement, probably in a conduit or a pre-chamber. An overlying pyroxene dunite represents the extract that gave rise to the chill and was emplaced either as a crystal slurry derived from the feeder conduit or as the crystallization product from a slightly later influx of primitive magma of komatiitic composition. This highly-Mg rich pyroxene dunite most likely acted as a barrier to the thermal erosion of the chill sequence as the chamber filled. The olivine in the pyroxene dunite layer is the most primitive yet recorded for the Bushveld Complex at Mg# 0.915, and the cores of associated orthopyroxene are Mg# 0.93. Compositions of the orthopyroxene in the quench and spinifex textured units range from Mg# 0.91 to 0.72 and preserve cores close to the original liquidus as well as tracking the complete in-situ solidification process. Olivine contains abundant dendritic exsolution structures of Cr-spinel and Al-rich clinopyroxene indicating that they formed at high temperature from incorporation of Ca, Al and Cr into olivine, with little time to equilibrate before emplacement. Chromite in the section is the most primitive yet recorded for the Bushveld Complex. The komatiite magma that was initially emplaced into the Bushveld chamber contained 19-20% MgO but trace element analysis indicates that it was derived from melting of a more primitive komatiite source which digested about 40% of typical Kaapvaal basement to give the strong crustal signature represented by trace elements and Sr isotopes. The evolved B1 magma, which compositionally is only broadly constrained, is regarded as the parental magma to the Lower and Critical Zones, but this is shown to represent a number of different magmas also derived from a komatiitic source with relatively high degrees of crustal contamination. The komatiite source to the Bushveld magmas could have been derived from subducted Archean ocean crust such as the silica- rich but highly depleted Commondale-type komatiites, as well as Barberton-type komatiites and komatiitic basalts. A mantle peridotite source is not considered a suitable bulk source because the Ni content in the Bushveld olivines (up to 4000 ppm) is indicative of a pyroxenite source in the mantle.

What Factors Control Platinum-Group Element (PGE) Abundances in Basalts From the Ontong Java Plateau?

NASA Astrophysics Data System (ADS)

Chazey, W. J.; Neal, C. R.

2002-12-01

Eleven samples encompassing four sites drilled by Ocean Drilling Program Leg 192 to the Ontong Java Plateau (OJP) were analyzed for major, trace and platinum-group (PGEs: Ir, Ru, Rh, Pt, and Pd) elements. Based on major and trace element chemistry, these are divided into two groups: a primitive group, which was newly discovered on Leg 192, and Kwaimbaita-type basalts, which are ubiquitous on the OJP (cf. Tejada et al., 2002, J. Pet. 43:449). The primitive group is relatively enriched in MgO, Ni, and Cr and relatively depleted in incompatible elements compared to the Kwaimbaita-type basalts. Petrography indicates that the fractionating phases during emplacement of both types of basalts were olivine and Cr-spinel +/- plagioclase +/- cpx. Normalized PGE profiles are fractionated, but exhibit a flattening between Ru and Ir and occasionally an enrichment in Ir. It has been shown that chromite can preferentially incorporate Os and Ru (Kd ?150) over Ir (Kd ?100), which may account for the Ir and Ru systematics. We do not consider sulfide to be a factor in fractionating the PGEs because it is either absent or present as a trace phase in these basalts and the OJP basalts are sulfur undersaturated (Michael and Cornell, 1996, EOS 77:714). Additionally, the primitive samples from the OJP also have Cu/Pd ratios (4500-8000) that are roughly similar to primitive mantle (7300), and have a generally flat transition from Pd to Y on a primitive mantle-normalized plot. It is unlikely that these samples reached sulfur saturation. The Kwaimbaita-type basalts have slightly elevated Cu/Pd ratios (9000-14000). While there are subtle differences between the PGE profiles of basalts from the Leg 192 drill cores compared to OJP basalts from subaerial outcrops in the Solomon Islands (e.g., the former have general lower Pt/Rh and higher Rh/Ru ratios), it is apparent that silicate and oxide phases are controlling the PGE profiles and abundances. For example, the six samples analyzed from Site 1185 demonstrate a positive correlation of Ru and Ir with Cr and Ni, suggesting a close association of these elements with the observed olivine and Cr-spinel phenocrysts. For all OJP basalts for which we have PGE data, there is a general positive correlation using MgO (or Cr or Ni) as a fractionation index and PGE abundance as well as ratios such as Pt/Y. Therefore, fractional crystallization controls the PGE contents of the OJP basalts. However, as noted by Ely and Neal (2002, Chem. Geol., in press) the abundances require a source enriched in the PGEs over upper mantle and, in some cases, primitive mantle. Such sources require a PGE enriched component that could be from the outer core, although as noted by Parkinson et al. (2001, EOS 82:F1398) this component is not always required. Further work is underway to substantiate this.

Zebrafish numb and numblike are involved in primitive erythrocyte differentiation.

PubMed

Bresciani, Erica; Confalonieri, Stefano; Cermenati, Solei; Cimbro, Simona; Foglia, Efrem; Beltrame, Monica; Di Fiore, Pier Paolo; Cotelli, Franco

2010-12-13

Notch signaling is an evolutionarily conserved regulatory circuitry implicated in cell fate determination in various developmental processes including hematopoietic stem cell self-renewal and differentiation of blood lineages. Known endogenous inhibitors of Notch activity are Numb-Nb and Numblike-Nbl, which play partially redundant functions in specifying and maintaining neuronal differentiation. Nb and Nbl are expressed in most tissues including embryonic and adult hematopoietic tissues in mice and humans, suggesting possible roles for these proteins in hematopoiesis. We employed zebrafish to investigate the possible functional role of Numb and Numblike during hematopoiesis, as this system allows a detailed analysis even in embryos with severe defects that would be lethal in other organisms. Here we describe that nb/nbl knockdown results in severe reduction or absence of embryonic erythrocytes in zebrafish. Interestingly, nb/nbl knocked-down embryos present severe downregulation of the erythroid transcription factor gata1. This results in erythroblasts which fail to mature and undergo apoptosis. Our results indicate that Notch activity is increased in embryos injected with nb/nbl morpholino, and we show that inhibition of Notch activation can partially rescue the hematopoietic phenotype. Our results provide the first in vivo evidence of an involvement of Numb and Numblike in zebrafish erythroid differentiation during primitive hematopoiesis. Furthermore, we found that, at least in part, the nb/nbl morphant phenotype is due to enhanced Notch activation within hematopoietic districts, which in turn results in primitive erythroid differentiation defects.

Undifferentiated myxoid lipoblastoma with PLAG1-HAS2 fusion in an infant; morphologically mimicking primitive myxoid mesenchymal tumor of infancy (PMMTI)--diagnostic importance of cytogenetic and molecular testing and literature review.

PubMed

Warren, Mikako; Turpin, Brian K; Mark, Melissa; Smolarek, Teresa A; Li, Xia

2016-01-01

Lipoblastoma is a benign myxoid neoplasm arising in young children that typically demonstrates adipose differentiation. It is often morphologically indistinguishable from primitive myxoid mesenchymal tumor of infancy (PMMTI), which is characterized by a well-circumscribed myxoid mass with a proliferation of primitive mesenchymal cells with mild cytologic atypia. PMMTI occurs in the first year of life and is known to have locally aggressive behavior. No specific genetic rearrangements have been reported to date. In contrast, the presence of PLAG1 (Pleomorphic Adenoma Gene 1) rearrangement is diagnostic for lipoblastoma. We hereby demonstrate the combined application of multiple approaches to tackle the diagnostic challenges of a rapidly growing neck tumor in a 3-month-old female. An incisional tumor biopsy had features of an undifferentiated, myxoid mesenchymal neoplasm mimicking PMMTI. However, tumor cells showed diffuse nuclear expression by immunohistochemical (IHC) stain. Conventional cytogenetic and fluorescence in situ hybridization (FISH) analyses as well as next generation sequencing (NGS) demonstrated evidence of PLAG1 rearrangement, confirming the diagnosis of lipoblastoma. This experience warrants that undifferentiated myxoid lipoblastoma can mimic PMMTI, and the combination of cytogenetic and molecular approaches is essential to distinguish these two myxoid neoplasms. Literature on lipoblastomas with relevant molecular and cytogenetic findings is summarized. Our case is the first lipoblastoma diagnosed with a PLAG1 fusion defined by NGS technology. Copyright © 2016 Elsevier Inc. All rights reserved.

JAK2/STAT5 inhibition by nilotinib with ruxolitinib contributes to the elimination of CML CD34+ cells in vitro and in vivo

PubMed Central

Gallipoli, Paolo; Cook, Amy; Rhodes, Susan; Hopcroft, Lisa; Wheadon, Helen; Whetton, Anthony D.; Jørgensen, Heather G.; Bhatia, Ravi

2014-01-01

Chronic myeloid leukemia (CML) stem cell survival is not dependent on BCR-ABL protein kinase and treatment with ABL tyrosine kinase inhibitors cures only a minority of CML patients, thus highlighting the need for novel therapeutic targets. The Janus kinase (JAK)2/signal transducer and activator of transcription (STAT)5 pathway has recently been explored for providing putative survival signals to CML stem/progenitor cells (SPCs) with contradictory results. We investigated the role of this pathway using the JAK2 inhibitor, ruxolitinib (RUX). We demonstrated that the combination of RUX, at clinically achievable concentrations, with the specific and potent tyrosine kinase inhibitor nilotinib, reduced the activity of the JAK2/STAT5 pathway in vitro relative to either single agent alone. These effects correlated with increased apoptosis of CML SPCs in vitro and a reduction in primitive quiescent CML stem cells, including NOD.Cg-Prkdcscid IL2rgtm1Wjl /SzJ mice repopulating cells, induced by combination treatment. A degree of toxicity toward normal SPCs was observed with the combination treatment, although this related to mature B-cell engraftment in NOD.Cg-Prkdcscid IL2rgtm1Wjl /SzJ mice with minimal effects on primitive CD34+ cells. These results support the JAK2/STAT5 pathway as a relevant therapeutic target in CML SPCs and endorse the current use of nilotinib in combination with RUX in clinical trials to eradicate persistent disease in CML patients. PMID:24957147

IGF-1 Signaling Plays an Important Role in the Formation of Three-Dimensional Laminated Neural Retina and Other Ocular Structures From Human Embryonic Stem Cells.

PubMed

Mellough, Carla B; Collin, Joseph; Khazim, Mahmoud; White, Kathryn; Sernagor, Evelyne; Steel, David H W; Lako, Majlinda

2015-08-01

We and others have previously demonstrated that retinal cells can be derived from human embryonic stem cells (hESCs) and induced pluripotent stem cells under defined culture conditions. While both cell types can give rise to retinal derivatives in the absence of inductive cues, this requires extended culture periods and gives lower overall yield. Further understanding of this innate differentiation ability, the identification of key factors that drive the differentiation process, and the development of clinically compatible culture conditions to reproducibly generate functional neural retina is an important goal for clinical cell based therapies. We now report that insulin-like growth factor 1 (IGF-1) can orchestrate the formation of three-dimensional ocular-like structures from hESCs which, in addition to retinal pigmented epithelium and neural retina, also contain primitive lens and corneal-like structures. Inhibition of IGF-1 receptor signaling significantly reduces the formation of optic vesicle and optic cups, while exogenous IGF-1 treatment enhances the formation of correctly laminated retinal tissue composed of multiple retinal phenotypes that is reminiscent of the developing vertebrate retina. Most importantly, hESC-derived photoreceptors exhibit advanced maturation features such as the presence of primitive rod- and cone-like photoreceptor inner and outer segments and phototransduction-related functional responses as early as 6.5 weeks of differentiation, making these derivatives promising candidates for cell replacement studies and in vitro disease modeling. © 2015 AlphaMed Press.

Spindle Cell Epithelioma of the Vagina Shows Immunohistochemical Staining Supporting Its Origin From a Primitive/Progenitor Cell Population

DTIC Science & Technology

2001-04-01

broader spectrum of immunohistochemical stains is presented that supports the origin of these tumors from a progenitor cell popula- tion. REPORT OF A CASE ...with S100 protein, with coexpression of cytokeratins and vimentin and expression of estrogen and progesterone receptors, as previously reported in...SCEVs. In addition, diffuse expres- sion of CD34, CD99, and Bcl-2 immunohistochemical stains was found, which has not previously been reported . The

An Open Source Agenda for Research Linking Text and Image Content Features.

ERIC Educational Resources Information Center

Goodrum, Abby A.; Rorvig, Mark E.; Jeong, Ki-Tai; Suresh, Chitturi

2001-01-01

Proposes methods to utilize image primitives to support term assignment for image classification. Proposes to release code for image analysis in a common tool set for other researchers to use. Of particular focus is the expansion of work by researchers in image indexing to include image content-based feature extraction capabilities in their work.…

Cultivation of marine sponges

NASA Astrophysics Data System (ADS)

Qu, Yi; Zhang, Wei; Li, Hua; Yu, Xingju; Jin, Meifang

2005-06-01

Sponges are the most primitive of multicellular animals, and are major pharmaceutical sources of marine secondary metabolites. A wide variety of new compounds have been isolated from sponges. In order to produce sufficient amounts of the compounds of the needed, it is necessary to obtain large amount of sponges. The production of sponge biomass has become a focus of marine biotechnology.

How primitive are the gases in Titan's atmosphere?

PubMed

Owen, T

1987-01-01

Titan's atmosphere contains a mixture of nitrogen, methane, argon, hydrogen, simple hydrocarbons and nitriles, carbon monoxide, and carbon dioxide. Sources of nitrogen may be as a product of the photodissociation of ammonia or trapped in the ices that formed the satellite. Reasons for the abundance of deuterium are examined and its association with nitrogen on Titan is explained.

Visible spectroscopy of the Sulamitis and Clarissa primitive families: a possible link to Erigone and Polana

NASA Astrophysics Data System (ADS)

Morate, David; de León, Julia; De Prá, Mário; Licandro, Javier; Cabrera-Lavers, Antonio; Campins, Humberto; Pinilla-Alonso, Noemí

2018-02-01

The low-inclination (i < 8∘) primitive asteroid families in the inner main belt, that is, Polana-Eulalia, Erigone, Sulamitis, and Clarissa, are considered to be the most likely sources of near-Earth asteroids (101955) Bennu and (162173) Ryugu. These two primitive NEAs will be visited by NASA OSIRIS-REx and JAXA Hayabusa 2 missions, respectively, with the aim of collecting samples of material from their surfaces and returning them back to Earth. In this context, the PRIMitive Asteroid Spectroscopic Survey (PRIMASS) was born, with the main aim to characterize the possible origins of these NEAs and constrain their dynamical evolution. As part of the PRIMASS survey we have already studied the Polana and Erigone collisional families in previously published works. The main goal of the work presented here is to compositionally characterize the Sulamitis and Clarissa families using visible spectroscopy. We have observed 97 asteroids (64 from Sulamitis and 33 from Clarissa) with the OSIRIS instrument (0.5-0.9 μm) at the 10.4 m Gran Telescopio Canarias (GTC). We found that about 60% of the sampled asteroids from the Sulamitis family show signs of aqueous alteration on their surfaces. We also found that the majority of the Clarissa members present no signs of hydration. The results obtained here show similarities between Sulamitis-Erigone and Clarissa-Polana collisional families. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A25

Interlaminar differences in the pyramidal cell phenotype in parietal cortex of an Indian bat, cynopterus sphinx.

PubMed

Srivastava, U C; Pathak, S V

2010-10-30

To study interlaminar phenotypic variations in the pyramidal neurons of parietal isocortex in bat (Cynopterus sphinx), Golgi and Nissl methods have been employed. The parietal isocortex is relatively thin in the bat as compared to prototheria with layer III, V and VI accounting for more than two—thirds of total cortical thickness. Thick cell free layer I and thinnest accentuated layer II are quite in connotation with other chiropterids. Poor demarcation of layer III/IV in the present study is also in connotation with primitive eutherian mammal (i.e. prototherian) and other chiropterids. Most of the pyramidal cells in the different layers of the parietal isocortex are of typical type as seen in other eutherians but differ significantly in terms of soma shape and size, extent of dendritic arbor, diameter of dendrites and spine density. Percentage of pyramidal neurons, diameter of apical dendrite and spine density on apical dendrite appear to follow an increasing trend from primitive to advanced mammals; but extent of dendrites are probably governed by the specific life patterns of these mammals. It is thus concluded that 'typical' pyramidal neurons in parietal isocortex are similar in therians but different from those in prototherians. It is possible that these cells might have arisen among early eutherians after divergence from prototherian stock.

Notochord morphogenesis in mice: Current understanding & open questions.

PubMed

Balmer, Sophie; Nowotschin, Sonja; Hadjantonakis, Anna-Katerina

2016-05-01

The notochord is a structure common to all chordates, and the feature that the phylum Chordata has been named after. It is a rod-like mesodermal structure that runs the anterior-posterior length of the embryo, adjacent to the ventral neural tube. The notochord plays a critical role in embryonic tissue patterning, for example the dorsal-ventral patterning of the neural tube. The cells that will come to form the notochord are specified at gastrulation. Axial mesodermal cells arising at the anterior primitive streak migrate anteriorly as the precursors of the notochord and populate the notochordal plate. Yet, even though a lot of interest has centered on investigating the functional and structural roles of the notochord, we still have a very rudimentary understanding of notochord morphogenesis. The events driving the formation of the notochord are rapid, taking place over the period of approximately a day in mice. In this commentary, we provide an overview of our current understanding of mouse notochord morphogenesis, from the initial specification of axial mesendodermal cells at the primitive streak, the emergence of these cells at the midline on the surface of the embryo, to their submergence and organization of the stereotypically positioned notochord. We will also discuss some key open questions. Developmental Dynamics 245:547-557, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Amphioxus and lamprey AP-2 genes: implications for neural crest evolution and migration patterns

NASA Technical Reports Server (NTRS)

Meulemans, Daniel; Bronner-Fraser, Marianne

2002-01-01

The neural crest is a uniquely vertebrate cell type present in the most basal vertebrates, but not in cephalochordates. We have studied differences in regulation of the neural crest marker AP-2 across two evolutionary transitions: invertebrate to vertebrate, and agnathan to gnathostome. Isolation and comparison of amphioxus, lamprey and axolotl AP-2 reveals its extensive expansion in the vertebrate dorsal neural tube and pharyngeal arches, implying co-option of AP-2 genes by neural crest cells early in vertebrate evolution. Expression in non-neural ectoderm is a conserved feature in amphioxus and vertebrates, suggesting an ancient role for AP-2 genes in this tissue. There is also common expression in subsets of ventrolateral neurons in the anterior neural tube, consistent with a primitive role in brain development. Comparison of AP-2 expression in axolotl and lamprey suggests an elaboration of cranial neural crest patterning in gnathostomes. However, migration of AP-2-expressing neural crest cells medial to the pharyngeal arch mesoderm appears to be a primitive feature retained in all vertebrates. Because AP-2 has essential roles in cranial neural crest differentiation and proliferation, the co-option of AP-2 by neural crest cells in the vertebrate lineage was a potentially crucial event in vertebrate evolution.

Post-transcriptional regulation in hematopoiesis: RNA binding proteins take control.

PubMed

de Rooij, Laura P M H; Chan, Derek C H; Keyvani Chahi, Ava; Hope, Kristin J

2018-06-13

Normal hematopoiesis is sustained through a carefully orchestrated balance between hematopoietic stem cell (HSC) self-renewal and differentiation. The functional importance of this axis is underscored by the severity of disease phenotypes initiated by abnormal HSC function, including myelodysplastic syndromes and hematopoietic malignancies. Major advances in the understanding of transcriptional regulation of primitive hematopoietic cells have been achieved, however, the post-transcriptional regulatory layer that may impinge on their behavior remains underexplored by comparison. Key players at this level include RNA binding proteins (RBPs), which execute precise and highly coordinated control of gene expression through modulation of RNA properties that include its splicing, polyadenylation, localization, degradation or translation. With the recent identification of RBPs having essential roles in regulating proliferation and cell fate decisions in other systems, there has been an increasing appreciation of the importance of post-transcriptional control at the stem cell level. Here we discuss our current understanding of RBP-driven post-transcriptional regulation in HSC, its implications for normal, perturbed and malignant hematopoiesis, as well as the most recent technological innovations aimed at RBP-RNA network characterization at the systems level. Emerging evidence highlights RBP-driven control as an underappreciated feature of primitive hematopoiesis, the greater understanding of which has important clinical implications.

The 1998-2001 submarine lava balloon eruption at the Serreta ridge (Azores archipelago): Constraints from volcanic facies architecture, isotope geochemistry and magnetic data

NASA Astrophysics Data System (ADS)

Madureira, Pedro; Rosa, Carlos; Marques, Ana Filipa; Silva, Pedro; Moreira, Manuel; Hamelin, Cédric; Relvas, Jorge; Lourenço, Nuno; Conceição, Patrícia; Pinto de Abreu, Manuel; Barriga, Fernando J. A. S.

2017-01-01

The most recent submarine eruption observed offshore the Azores archipelago occurred between 1998 and 2001 along the submarine Serreta ridge (SSR), 4-5 nautical miles WNW of Terceira Island. This submarine eruption delivered abundant basaltic lava balloons floating at the sea surface and significantly changed the bathymetry around the eruption area. Our work combines bathymetry, volcanic facies cartography, petrography, rock magnetism and geochemistry in order to (1) track the possible vent source at seabed, (2) better constrain the Azores magma source(s) sampled through the Serreta submarine volcanic event, and (3) interpret the data within the small-scale mantle source heterogeneity framework that has been demonstrated for the Azores archipelago. Lava balloons sampled at sea surface display a radiogenic signature, which is also correlated with relatively primitive (low) 4He/3He isotopic ratios. Conversely, SSR lavas are characterized by significantly lower radiogenic 87Sr/86Sr, 206Pb/204Pb and 208Pb/204Pb ratios than the lava balloons and the onshore lavas from the Terceira Island. SSR lavas are primitive, but incompatible trace-enriched. Apparent decoupling between the enriched incompatible trace element abundances and depleted radiogenic isotope ratios is best explained by binary mixing of a depleted MORB source and a HIMU­type component into magma batches that evolved by similar shallower processes in their travel to the surface. The collected data suggest that the freshest samples collected in the SSR may correspond to volcanic products of an unnoticed and more recent eruption than the 1998-2001 episode.

Dynamic Primitives of Motor Behavior

PubMed Central

Hogan, Neville; Sternad, Dagmar

2013-01-01

We present in outline a theory of sensorimotor control based on dynamic primitives, which we define as attractors. To account for the broad class of human interactive behaviors—especially tool use—we propose three distinct primitives: submovements, oscillations and mechanical impedances, the latter necessary for interaction with objects. Due to fundamental features of the neuromuscular system, most notably its slow response, we argue that encoding in terms of parameterized primitives may be an essential simplification required for learning, performance, and retention of complex skills. Primitives may simultaneously and sequentially be combined to produce observable forces and motions. This may be achieved by defining a virtual trajectory composed of submovements and/or oscillations interacting with impedances. Identifying primitives requires care: in principle, overlapping submovements would be sufficient to compose all observed movements but biological evidence shows that oscillations are a distinct primitive. Conversely, we suggest that kinematic synergies, frequently discussed as primitives of complex actions, may be an emergent consequence of neuromuscular impedance. To illustrate how these dynamic primitives may account for complex actions, we briefly review three types of interactive behaviors: constrained motion, impact tasks, and manipulation of dynamic objects. PMID:23124919

Strontium and neodymium isotopic evidence for the heterogeneous nature and development of the mantle beneath Afar (Ethiopia)

NASA Astrophysics Data System (ADS)

Betton, P. J.; Civetta, L.

1984-11-01

Neodymium isotope and REE analyses of recent volcanic rocks and spinel lherzolite nodules from the Afar area are reported. The 143Nd/ 144Nd ratios of the volcanic rocks range from 0.51286 to 0.51304, similar to the range recorded from Iceland. However, the 87Sr/ 86Sr ratios display a distinctly greater range (0.70328-0.70410) than those reported from the primitive rocks of Iceland. Whole rock samples and mineral separates from the spinel lherzolite nodules exhibit uniform 143Nd/ 144Nd ratios (ca. 0.5129) but varied 87Sr/ 86Sr ratios in the range 0.70427-0.70528. The Sr sbnd Nd isotope variations suggest that the volcanic rocks may have been produced by mixing between two reservoirs with distinct isotopic compositions. Two possible magma reservoirs in this area are the source which produced the "MORB-type" volcanics in the Red Sea and Gulf of Aden and the anomalous source represented by the nodule suite. The isotopic composition of the volcanics is compatible with mixing between these two reservoirs. It is shown that the anomalous source with a high 87Sr/ 86Sr ratio cannot have been produced by simple processes of partial melting and mixing within normal mantle. Instead the high 87Sr/ 86Sr is equated with a fluid phase. A primitive cognate fluid, subducted seawater or altered oceanic lithosphere may have been responsible for the generation of the source with a high 87Sr/ 86Sr ratio.

Foraging recruitment by the Giant Tropical Ant Paraponera clavata (Hymenoptera, Formicidae)

USGS Publications Warehouse

Barrett, Bruce A.; Jorgenson, Clive D.; Looman, Sandra J.

1985-01-01

Increased foraging of an exceptionally abundant, but ephemeral, food source by ants can result from foraging excitement that does not include pheromone trails, tandem running, or from recruitment of other workers along pheromone trails (Carrol and Janzen, 1973). They also provided rationale for two types of short-lived pheromone trails resulting in mass or group recruitment. These both seem to fall into the Type II foraging strategy described by Oster and Wilson (1978). Neither of these discussions conveniently allow for pheromone recruitment by relatively small colonies of a primitive monomorphic species such as Paraponera clavata. Our observations suggest that recruitment to an abundant ephemeral food source does occur naturally and can be induced artificially in colonies of P. clavata.Paraponera clavata is considered primitive (Wilson, 1958), particularly in foraging habits (Young and Hermann, 1980; Young, 1977). Hermann (1973, 1975) reported the P. clavata, unlike more advanced species, forages independently; following shot periods of apparent group activity outside of the colony (Young and Hermann, 1980). It reportedly does not return to a food source when only part has been harvested. After returning to its colony with booty, a single worker resumes foraging independently, with no observable tendency to return to partially harvested booty or without recruiting additional workers to collect the remaining food (Hermann, 1973; Young and Hermann, 1980). Reports of independent foraging, lack of forager recruitment, and apparent lack of food source fidelity resulted in the assumption that P. clavata probably lacks an effective pheromone trail communication system (Young and Hermann, 1980).

Observations of Nitrogen Fractionation in Prestellar Cores: Nitriles Tracing Interstellar Chemistry

NASA Technical Reports Server (NTRS)

Milam, S. N.; Charnley, S. B.

2012-01-01

Primitive materials provide important clues on the processes that occurred during the formation and early evolution of the Solar System. Space-based and ground-based observations of cometary comae show that comets appear to contain a mixture of the products of both interstellar and nebular chemistries. Significant 15-nitrogen enrichments have been measured in CN and HCN towards a number of comets and may suggest an origin of interstellar chemical fractionation. Additionally, large N-15 enhancements are found in meteorites and has also led to to the view that the N-15 traces material formed in the interstellar medium (ISM), although multiple sources cannot be excluded. Here, we show the results of observations of the nitrogen and carbon fractionation in prestellar cores for various N-bearing species to decipher the origin of primitive material isotopic enrichments.

Cumberland Falls chondritic inclusions. III - Consortium study of relationship to inclusions in Allan Hills 78113 aubrite

NASA Astrophysics Data System (ADS)

Lipschutz, Michael E.; Verkouteren, R. Michael; Sears, Derek W. G.; Hasan, Fouad A.; Prinz, Martin.; Weisberg, M. K.; Nehru, Cherukupalli E.; Delaney, Jeremy S.; Grossman, Lawrence; Boily, Michel

1988-07-01

The contents of Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Sb, Se, Te, Tl, U, and Zn in large chondritic clasts from the Cumbersand Falls aubrite were determined by radiochemical neutron activation analysis, and the results, together with the results of a mineralogical investigation, were compared with respective data obtained for three primitive inclusions from the ALH A78113 aubrite. The results indicated that the clasts from both aubrite sources constitute a single chondritic suite. The analyses data, together with the results of thermoluminescence data for Cumberland Falls chondritic inclusions and achondritic host, indicate that inclusions in Cumberland Falls and in ALH A78113 aubrite represent a primitive chondrite sample suite whose properties were established during primary nebular accretion and condensation over a broad redox range.

Coordinates Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

NASA Technical Reports Server (NTRS)

Keller, L. P.; Snead, C.; McKeegan, K. D.

2016-01-01

Interplanetary dust particles (IDPs) collected in the stratosphere fall into two major groups: an anhydrous group termed the "chondritic-porous (CP) IDPs and a hydrated group, the "chondritic-smooth (CS) IDPs, although rare IDPs with mineralogies intermediate between these two groups are known [1]. The CP-IDPs are widely believed to be derived from cometary sources [e.g. 2]. The hydrated CS-IDPs show mineralogical similarities to heavily aqueously altered carbonaceous chondrites (e.g. CI chondrites), but only a few have been directly linked to carbonaceous meteorite parent bodies [e.g. 3, 4]. Most CS-IDPs show distinct chemical [5] and oxygen isotopic composition differences [6-8] from primitive carbonaceous chondrites. Here, we report on our coordinated analyses of a suite of carbon-rich CS-IDPs focusing on their bulk compositions, mineralogy, mineral chemistry, and isotopic compositions.

Long-term hematopoietic stem cell damage in a murine model of the hematopoietic syndrome of the acute radiation syndrome.

PubMed

Chua, Hui Lin; Plett, P Artur; Sampson, Carol H; Joshi, Mandar; Tabbey, Rebeka; Katz, Barry P; MacVittie, Thomas J; Orschell, Christie M

2012-10-01

Residual bone marrow damage (RBMD) persists for years following exposure to radiation and is believed to be due to decreased self-renewal potential of radiation-damaged hematopoietic stem cells (HSC). Current literature has examined primarily sublethal doses of radiation and time points within a few months of exposure. In this study, the authors examined RBMD in mice surviving lethal doses of total body ionizing irradiation (TBI) in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS). Survivors were analyzed at various time points up to 19 mo post-TBI for hematopoietic function. The competitive bone marrow (BM) repopulating potential of 150 purified c-Kit+ Sca-1+ lineage- CD150+ cells (KSLCD150+) remained severely deficient throughout the study compared to KSLCD150+ cells from non-TBI age-matched controls. The minimal engraftment from these TBI HSCs is predominantly myeloid, with minimal production of lymphocytes both in vitro and in vivo. All classes of blood cells as well as BM cellularity were significantly decreased in TBI mice, especially at later time points as mice aged. Primitive BM hematopoietic cells (KSLCD150+) displayed significantly increased cell cycling in TBI mice at all time points, which may be a physiological attempt to maintain HSC numbers in the post-irradiation state. Taken together, these data suggest that the increased cycling among primitive hematopoietic cells in survivors of lethal radiation may contribute to long-term HSC exhaustion and subsequent RBMD, exacerbated by the added insult of aging at later time points.

What Everyone Should Know about Archeans

ERIC Educational Resources Information Center

Freeland, Peter

2013-01-01

For many years biologists supposed that one group of microorganisms, which they called archaebacteria, were an ancient and primitive type of bacteria. Following biochemical analysis of their RNA and other cell components, it soon became clear that their distinct features merited classification in a separate domain, the archea. From an evolutionary…

Alisertib in Treating Young Patients With Recurrent or Refractory Solid Tumors or Leukemia

ClinicalTrials.gov

2017-09-21

Hepatoblastoma; Previously Treated Childhood Rhabdomyosarcoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Kidney Neoplasm; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent Osteosarcoma

HEPATOBLASTOMAS IN THE MUMMICHOG, FUNDULUS HETEROCLITUS (L.), FROM A CREOSOTE-CONTAMINATED ENVIRONMENT: A HISTOLOGIC, ULTRASTRUCTURAL AND IMMUNOHISTOCHEMICAL STUDY

EPA Science Inventory

A detailed histologic and ultrastructural description of two cases of hepatoblastoma, a primitive liver cell neoplasm, is provided from mummichog, Fundulus heteroclitus(L.), inhabiting a creosote-contaminated site in the Elizabeth River, Virginia, USA. Both neoplasms were multifo...

Postirradiation malignant fibrous histiocytoma of the lung. Demonstration of alpha 1-antitrypsin-like material in neoplastic cells.

PubMed

Chowdhury, L N; Swerdlow, M A; Jao, W; Kathpalia, S; Desser, R K

1980-12-01

A metastasizing fibrous histiocytoma arising in the lung of a patient who received radiation therapy and long-term chemotherapy for malignant lymphoma is presented. Ultrastructural studies revealed fibroblast-like and histiocyte-like cells, cells of intermediate type showing ultrastructural features of both fibroblast-like and histiocyte-like cells, primitive mesenchymal cells, multinucleate tumor cells, and xanthomatous cells. The neoplastic cells showed dilated rough endoplasmic reticula with intracisternal accumulation of electron-dense material forming lattice-like structures. Direct immunofluorescence staining of the neoplastic cells using antihuman alpha 1-antitrypsin showed specific activity, with fluorescent deposits exhibiting interlacing globular formations. These findings and their implications are discussed.

Molecular Features of Neural Stem Cells Enable their Enrichment Using Pharmacological Inhibitors of Survival-Promoting Kinases

PubMed Central

Brazel, Christine Y.; Alaythan, Abdulaziz A.; Felling, Ryan J.; Calderon, Frances; Levison, Steven W.

2013-01-01

Isolating a pure population of neural stem cells (NSCs) has been difficult since no exclusive surface markers have been identified for panning or FACS purification. Moreover, additional refinements for maintaining NSCs in culture are required, since NSCs generate a variety of neural precursors (NPs) as they proliferate. Here, we demonstrate that postnatal rat NPs express low levels of pro-apoptotic molecules and resist PI3K and ERK1/2 inhibition as compared to late oligodendrocyte progenitors. Furthermore, maintaining SVZ precursors in LY294002 and PD98059, inhibitors of PI3K and ERK1/2 signaling, eliminated lineage-restricted precursors as revealed by enrichment for Nestin+/SOX-2+ cells. The cells that survived formed neurospheres and 89% of these neurospheres were tripotential, generating neurons, astrocytes and oligodendrocytes. Without this enrichment step, less than 50% of the NPs were Nestin+/SOX-2+ and 42% of the neurospheres were tripotential. Additionally, neurospheres enriched using this procedure produced 3-times more secondary neurospheres, supporting the conclusion that this procedure enriches for NSCs. A number of genes that enhance survival were more highly expressed in neurospheres compared to late oligodendrocyte progenitors. Altogether, these studies demonstrate that primitive neural precursors can be enriched using a relatively simple and inexpensive means that will facilitate cell replacement strategies using stem cells as well as other studies whose goal is to reveal the fundamental properties of primitive neural precursors. PMID:24032666

Common tree shrews and primates share leukocyte membrane antigens.

PubMed

Palley, L S; Schlossman, S F; Letvin, N L

1984-01-01

Monoclonal antibodies reactive with human peripheral blood lymphocyte and myeloid cell surface antigens were utilized to study the phylogeny of the common tree shrew. Blood cells from the common tree shrew, but not the bat or short-tailed shrew, react with certain of these antibodies. These data strengthen the argument that the Tupaiidae are primitive primates rather than insectivores. They also indicate that this approach should be useful for further work in taxonomic systemization.

Cell lineage allocation in equine blastocysts produced in vitro under varying glucose concentrations.

PubMed

Choi, Young-Ho; Ross, Pablo; Velez, Isabel C; Macías-García, B; Riera, Fernando L; Hinrichs, Katrin

2015-07-01

Equine embryos develop in vitro in the presence of high glucose concentrations, but little is known about their requirements for development. We evaluated the effect of glucose concentrations in medium on blastocyst development after ICSI. In experiment 1, there were no significant differences in rates of blastocyst formation among embryos cultured in our standard medium (DMEM/F-12), which contained >16 mM glucose, and those cultured in a minimal-glucose embryo culture medium (<1 mM; Global medium, GB), with either 0 added glucose for the first 5 days, then 20 mM (0-20) or 20 mM for the entire culture period (20-20). In experiment 2, there were no significant differences in the rates of blastocyst development (31-46%) for embryos cultured in four glucose treatments in GB (0-10, 0-20, 5-10, or 5-20). Blastocysts were evaluated by immunofluorescence for lineage-specific markers. All cells stained positively for POU5F1. An inner cluster of cells was identified that included presumptive primitive endoderm cells (GATA6-positive) and presumptive epiblast (EPI) cells. The 5-20 treatment resulted in a significantly lower number of presumptive EPI-lineage cells than the 0-20 treatment did. GATA6-positive cells appeared to be allocated to the primitive endoderm independent of the formation of an inner cell mass, as was previously hypothesized for equine embryos. These data demonstrate that equine blastocyst development is not dependent on high glucose concentrations during early culture; rather, environmental glucose may affect cell allocation. They also present the first analysis of cell lineage allocation in in vitro-fertilized equine blastocysts. These findings expand our understanding of the factors that affect embryo development in the horse. © 2015 Society for Reproduction and Fertility.

Error analysis in stereo vision for location measurement of 3D point

NASA Astrophysics Data System (ADS)

Li, Yunting; Zhang, Jun; Tian, Jinwen

2015-12-01

Location measurement of 3D point in stereo vision is subjected to different sources of uncertainty that propagate to the final result. For current methods of error analysis, most of them are based on ideal intersection model to calculate the uncertainty region of point location via intersecting two fields of view of pixel that may produce loose bounds. Besides, only a few of sources of error such as pixel error or camera position are taken into account in the process of analysis. In this paper we present a straightforward and available method to estimate the location error that is taken most of source of error into account. We summed up and simplified all the input errors to five parameters by rotation transformation. Then we use the fast algorithm of midpoint method to deduce the mathematical relationships between target point and the parameters. Thus, the expectations and covariance matrix of 3D point location would be obtained, which can constitute the uncertainty region of point location. Afterwards, we turned back to the error propagation of the primitive input errors in the stereo system and throughout the whole analysis process from primitive input errors to localization error. Our method has the same level of computational complexity as the state-of-the-art method. Finally, extensive experiments are performed to verify the performance of our methods.

Stochastic Ocean Predictions with Dynamically-Orthogonal Primitive Equations

NASA Astrophysics Data System (ADS)

Subramani, D. N.; Haley, P., Jr.; Lermusiaux, P. F. J.

2017-12-01

The coastal ocean is a prime example of multiscale nonlinear fluid dynamics. Ocean fields in such regions are complex and intermittent with unstationary heterogeneous statistics. Due to the limited measurements, there are multiple sources of uncertainties, including the initial conditions, boundary conditions, forcing, parameters, and even the model parameterizations and equations themselves. For efficient and rigorous quantification and prediction of these uncertainities, the stochastic Dynamically Orthogonal (DO) PDEs for a primitive equation ocean modeling system with a nonlinear free-surface are derived and numerical schemes for their space-time integration are obtained. Detailed numerical studies with idealized-to-realistic regional ocean dynamics are completed. These include consistency checks for the numerical schemes and comparisons with ensemble realizations. As an illustrative example, we simulate the 4-d multiscale uncertainty in the Middle Atlantic/New York Bight region during the months of Jan to Mar 2017. To provide intitial conditions for the uncertainty subspace, uncertainties in the region were objectively analyzed using historical data. The DO primitive equations were subsequently integrated in space and time. The probability distribution function (pdf) of the ocean fields is compared to in-situ, remote sensing, and opportunity data collected during the coincident POSYDON experiment. Results show that our probabilistic predictions had skill and are 3- to 4- orders of magnitude faster than classic ensemble schemes.

The atmosphere of the primitive earth and the prebiotic synthesis of organic compounds

NASA Technical Reports Server (NTRS)

Miller, S. L.; Schlesinger, G.

1983-01-01

The prebiotic synthesis of organic compounds is investigated using a spark discharge on various simulated prebiotic atmospheres at 25 C. It is found that glycine is almost the only amino acid produced from the model atmospheres containing CO and CO2. These results show that the maximum yield is about the same for the three carbon sources (CO, CO2, and CH4) at high H2/carbon ratios, but that CH4 is superior at low H2/carbon ratios. CH4 is found to yield a much greater variety of amino acids than either CO or CO2. If it is assumed that amino acids more complex than glycine were required for the origin of life, then these findings indicate the need for CH4 in the primitive atmosphere. The yields of cyanide and formaldehyde are shown to parallel the amino acid results, with yields of HCN and H2CO as high as 13 percent based on carbon. Ammonia is also found to be produced from N2 in experiments with no added NH3 in yields as high as 4.9 percent. These results indicate that large amounts of NH3 would have been synthesized on the primitive earth by electric discharges.

Extremely thick cell walls and low mesophyll conductance: welcome to the world of ancient living!

PubMed Central

Tosens, Tiina; Laanisto, Lauri; Niinemets, Ülo

2017-01-01

Abstract Mesophyll conductance is thought to be an important photosynthetic limitation in gymnosperms, but they currently constitute the most understudied plant group in regard to the extent to which photosynthesis and intrinsic water use efficiency are limited by mesophyll conductance. A comprehensive analysis of leaf gas exchange, photosynthetic limitations, mesophyll conductance (calculated by three methods previously used for across-species comparisons), and the underlying ultra-anatomical, morphological and chemical traits in 11 gymnosperm species varying in evolutionary history was performed to gain insight into the evolution of structural and physiological controls on photosynthesis at the lower return end of the leaf economics spectrum. Two primitive herbaceous species were included in order to provide greater evolutionary context. Low mesophyll conductance was the main limiting factor of photosynthesis in the majority of species. The strongest sources of limitation were extremely thick mesophyll cell walls, high chloroplast thickness and variation in chloroplast shape and size, and the low exposed surface area of chloroplasts per unit leaf area. In gymnosperms, the negative relationship between net assimilation per mass and leaf mass per area reflected an increased mesophyll cell wall thickness, whereas the easy-to-measure integrative trait of leaf mass per area failed to predict the underlying ultrastructural traits limiting mesophyll conductance. PMID:28419340

The Late Devonian Gogo Formation Lägerstatte of Western Australia: Exceptional Early Vertebrate Preservation and Diversity

NASA Astrophysics Data System (ADS)

Long, John A.; Trinajstic, Kate

2010-05-01

The Gogo Formation of Western Australia preserves a unique Late Devonian (Frasnian) reef fauna. The exceptional three-dimensional preservation of macrofossils combined with unprecedented soft-tissue preservation (including muscle bundles, nerve cells, and umbilical structures) has yielded a particularly rich assemblage with almost 50 species of fishes described. The most significant discoveries have contributed to resolving placoderm phylogeny and elucidating their reproductive physiology. Specifically, these discoveries have produced data on the oldest known vertebrate embryos; the anatomy of the primitive actinopterygian neurocranium and phylogeny of the earliest actinopterygians; the histology, radiation, and plasticity of dipnoan (lungfish) dental and cranial structures; the anatomy and functional morphology of the extinct onychodonts; and the anatomy of the primitive tetrapodomorph head and pectoral fin.

Neuromuscular transmission in a primitive insect: modulation by octopamine, and catch-like tension.

PubMed

Hoyle, G

1984-01-01

The third pair of legs of the primitive New Zealand orthopteran insect, the " weta ", has and innervation and muscle cell distribution exactly similar to that of locusts, but wetas do not jump. Neuromuscular transmission to the slow excitatory axon ( SETi ) is potentiated more than 10-fold by the natural modulator octopamine (OCT). A brief burst of SETi impulses following infusion of as little as 10(-8) M OCT is followed by a very long-lasting plateau of catch-like tension (CT). The plateau is abruptly relaxed by a single inhibitory impulse, or even by a single SETi impulse if this arrives no sooner than about 30 sec following excitation. CT is used by wetas in a defense posture. Locusts and grasshoppers have a different type of modulation by OCT.

Preferential uptake of ribose by primitive cells might explain why RNA was favored over its analogs

NASA Astrophysics Data System (ADS)

Pohorille, Andrew; Wei, Chenyu

Permeation of molecules through membranes is a fundamental process in biological systems, which not only involves mass and signal transfers between the interior of a contemporary cell and its environment, but was also of crucial importance in the origin of life. In the absence of complex protein transporters, nutrients and building blocks of biopolymers must have been able to permeate membranes at sufficient rates to support primordial metabolism and cel-lular reproduction. From this perspective one class of solutes that is of special interest are monosaccharides, which serve not only as nutritional molecules but also as building blocks for information molecules. In particular, ribose is a part of the RNA backbone, but RNA analogs containing a number of other sugars have also been shown to form stable duplexes. Why, among these possibilities, ribose (and, subsequently, deoxyribose) was selected for the backbone of information polymers is still poorly understood. It was recently found that ribose permeates membranes an order of magnitude faster than its diastereomers, arabinose and xylose [1]. On this basis it was hypothesized that differences in membrane permeability to aldopentoses provide a mechanism for preferential delivery of ribose to primitive cells for subsequent, selective incorporation into nucleotides and their polymers. However, the origins of these unusually large differences had not been well understood. We addressed this issue in molecular dynamics simulations combined with free energy calculations. It was found that the free energy barrier for transferring ribose from water to the bilayer is lower by 1.5-2 kcal/mol than the barrier for transferring the other two aldopentoses. The calculated [2] and measured [1] permeability coefficients are in an excellent agreement. The sugar structures that permeate the membrane are -pyranoses, with a possible contribution of the -anomer for arabinose. The furanoid form of ribose is not substantially involved in perme-ation, even though it is non-negligibly populated in aqueous solution. The differences in free energy barrier between ribose and arabinose or xylose are due to stronger, highly cooperative, intramolecular interactions between consecutive exocyclic hydroxyl groups, which are stable in non-polar media, but rare in water. Most recently, we extended calculations of permeations to ribonucleosides and their anomers. We determined that, in contrast to sugars, permeation of membranes to these species is nearly identical. This is because sugars of nucleotides exist in the furanose rather than pyranose form. In this form intermolecular interactions between hydroxyl groups are not nearly as efficient for sterical reasons. Our results contribute to the discussion about autotrophic vs. heterotrophic origins of life. Chemical reactions inside protobiological vesicle required supply of organic material from the environment. What was the inventory of organics that must have been delivered to primitive cells is still being debated. According to the autotrophic hypothesis, ancestors of cells pro-duced complex organic molecules from simple substrates. In contrast, the heterotrophic model implies that protocells were able to utilize complex organics delivered from external sources. A possibility of sufficiently efficient uptake of molecules needed to build biopolymers provides an important argument supporting the heterotrophic hypothesis [3]. Viewed in the context of the "RNA world" hypothesis [4], which states that RNA molecules were the first biological poly-mers and acted as both catalysts of biochemical reactions and information storage systems, our results demonstrate that, in the absence of sophisticated mechanisms available to contemporary organisms for achieving selectivity during synthesis and transmembrane transport, preferential uptake of ribose by primitive cells might have provided a kinetic mechanism that favored its selective incorporation into nucleic acids and, ultimately, the emergence of RNA. The same mechanism, however, could not have operated if the species transported across protocellular walls were nucleosides (or, presumably, nucleotides) rather than sugars. References: [1] M. G. Sacerdote and J. W. Szostak, 2005, Proc. Natl. Acad. Sci USA, 102, 6004; [2] C. Wei, and A. Pohorille, 2009, J. Am. Chem. Soc. 131, 10237: [3] S. S. Mansy, J. P. Schrum, M. Krishnamurthy, S. Tobé, D. A. Treco and J. W. Szostak, 2008, Nature. 454, 122; [4] W. Gilbert, 1986, Nature 319, 618.

Hair Cell Heterogeneity in the Goldfish Saccule

NASA Technical Reports Server (NTRS)

Saidel, William M.; Lanford, Pamela J.; Yan, Hong Y.; Popper, Arthur N.

1995-01-01

A set of cytological studies performed in the utricle and saccule of Astronotus ocellatus (Teleostei, Percomorphi, Cichlidae) identified two basic types of hair cells and others with some intermediate characteristics. This paper reports on applying the same techniques to the saccule of Carassius auratus (Teleostei, Otophysi, Cyprinidae) and demonstrates similar types of hair cells to those found in Astronotus. Since Carassius and Astronous are species of extreme taxonomic distance within the Euteteostei, two classes of mechanoreceptive hair cells are likely to represent the primitive condition for sensory receptors in the euteleost inner ear and perhaps in all bony fish ears.

Vorinostat With or Without Isotretinoin in Treating Young Patients With Recurrent or Refractory Solid Tumors, Lymphoma, or Leukemia

ClinicalTrials.gov

2014-06-16

Childhood Acute Promyelocytic Leukemia (M3); Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Burkitt Lymphoma; Childhood Chronic Myelogenous Leukemia; Childhood Diffuse Large Cell Lymphoma; Childhood Immunoblastic Large Cell Lymphoma; Juvenile Myelomonocytic Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Neuroblastoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Relapsing Chronic Myelogenous Leukemia; Unspecified Childhood Solid Tumor, Protocol Specific

Unprecedented concentrations of indigenous amino acids in primitive CR meteorites

NASA Astrophysics Data System (ADS)

Ehrenfreund, Pascale; Martins, Zita; Alexander, Conel; Orzechowska, Grazyna; Fogel, Marylin

CR meteorites are among the most primitive meteorites. We have performed pioneering work determining the compositional characteristics of amino acids in this type of carbonaceous chondrites. We report the first measurements of amino acids in Antarctic CR meteorites, two of which show the highest amino acid concentrations ever found in a chondrite. We have analyzed the amino acid content of the Antarctic CRs EET92042, GRA95229 and GRO95577 using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatography-mass spectrometry (GC-MS). Additionally, compound-specific carbon isotopic measurements for most of the individual amino acids from the EET92042 and GRA95229 meteorites were achieved by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our data show that EET92042 and GRA95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations of 180 and 249 parts-per-million (ppm), respectively. GRO95577, however, is depleted in amino acids (<1 ppm). The most abundant amino acids present in the EET92042 and GRA95229 meteorites are the α-amino acids glycine, isovaline, α-aminoisobutyric acid (α-AIB), and alanine, with δ 13 C values ranging from +31.6% to +50.5%. The highly enriched carbon isotope results together with racemic enantiomeric ratios determined for most amino acids indicate that primitive organic matter was preserved in these meteorites. In addition, the relative abundances of α-AIB and β-alanine amongst Antarctic CR meteorites appear to correspond to the degree of aqueous alteration on their respective parent body. Investigating the abundances and isotopic composition of amino acids in primitive chondrites helps to understand the role of meteorites as a source of extraterrestrial prebiotic organic compounds to the early Earth.

Self assembly properties of primitive organic compounds

NASA Technical Reports Server (NTRS)

Deamer, D. W.

1991-01-01

A central event in the origin of life was the self-assembly of amphiphilic, lipid-like compounds into closed microenvironments. If a primitive macromolecular replicating system could be encapsulated within a vesicular membrane, the components of the system would share the same microenvironment, and the result would be a step toward true cellular function. The goal of our research has been to determine what amphiphilic molecules might plausibly have been available on the early Earth to participate in the formation of such boundary structures. To this end, we have investigated primitive organic mixtures present in carbonaceous meteorites such as the Murchison meteorite, which contains 1-2 percent of its mass in the form of organic carbon compounds. It is likely that such compounds contributed to the inventory of organic carbon on the prebiotic earth, and were available to participate in chemical evolution leading to the emergence of the first cellular life forms. We found that Murchison components extracted into non-polar solvent systems are surface active, a clear indication of amphiphilic character. One acidic fraction self-assembles into vesicular membranes that provide permeability barriers to polar solutes. Other evidence indicates that the membranes are bimolecular layers similar to those formed by contemporary membrane lipids. We conclude that bilayer membrane formation by primitive amphiphiles on the early Earth is feasible. However, only a minor fraction of acidic amphiphiles assembles into bilayers, and the resulting membranes require narrowly defined conditions of pH and ionic composition to be stable. It seems unlikely, therefore, that meteoritic infall was a direct source of membrane amphiphiles. Instead, the hydrocarbon components and their derivatives more probably would provide an organic stock available for chemical evolution. Our current research is directed at possible reactions which would generate substantial quantities of membranogenic amphiphiles. One possibility is photochemical oxidation of hydrocarbons.

Melting of the primitive martian mantle at 0.5-2.2 GPa and the origin of basalts and alkaline rocks on Mars

NASA Astrophysics Data System (ADS)

Collinet, Max; Médard, Etienne; Charlier, Bernard; Vander Auwera, Jacqueline; Grove, Timothy L.

2015-10-01

We have performed piston-cylinder experiments on a primitive martian mantle composition between 0.5 and 2.2 GPa and 1160 to 1550 °C. The composition of melts and residual minerals constrain the possible melting processes on Mars at 50 to 200 km depth under nominally anhydrous conditions. Silicate melts produced by low degrees of melting (<10 wt.%) were analyzed in layers of vitreous carbon spheres or in micro-cracks inside the graphite capsule. The total range of melt fractions investigated extends from 5 to 50 wt.%, and the liquids produced display variable SiO2 (43.7-59.0 wt.%), MgO (5.3-18.6 wt.%) and Na2O + K2O (1.0-6.5 wt.%) contents. We provide a new equation to estimate the solidus temperature of the martian mantle: T (°C) = 1033 + 168.1 P (GPa) - 14.22P2 (GPa), which places the solidus 50 °C below that of fertile terrestrial peridotites. Low- and high-degree melts are compared to martian alkaline rocks and basalts, respectively. We suggest that the parental melt of Adirondack-class basalts was produced by ∼25 wt.% melting of the primitive martian mantle at 1.5 GPa (∼135 km) and ∼1400 °C. Despite its brecciated nature, NWA 7034/7533 might be composed of material that initially crystallized from a primary melt produced by ∼10-30 wt.% melting at the same pressure. Other igneous rocks from Mars require mantle reservoirs with different CaO/Al2O3 and FeO/MgO ratios or the action of fractional crystallization. Alkaline rocks can be derived from mantle sources with alkali contents (∼0.5 wt.%) similar to the primitive mantle.

18F-FLT Positron Emission Tomography and Diffusion-Weighted Magnetic Resonance Imaging in Planning Surgery and Radiation Therapy and Measuring Response in Patients With Newly Diagnosed Ewing Sarcoma

ClinicalTrials.gov

2017-11-16

Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Ewing Sarcoma of Bone; Extraosseous Ewing Sarcoma; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Untreated Childhood Supratentorial Primitive Neuroectodermal Tumor

Experimental Phase Relations of Hydrous, Primitive Melts: Implications for variably depleted mantle melting in arcs and the generation of primitive high-SiO2 melts

NASA Astrophysics Data System (ADS)

Weaver, S.; Wallace, P. J.; Johnston, A.

2010-12-01

There has been considerable experimental and theoretical work on how the introduction of H2O-rich fluids into the mantle wedge affects partial melting in arcs and chemical evolution of mantle melts as they migrate through the mantle. Studies aimed at describing these processes have become largely quantitative, with an emphasis on creating models that suitably predict the production and evolution of melts and describe the thermal state of arcs worldwide. A complete experimental data set that explores the P-T conditions of melt generation and subsequent melt extraction is crucial to the development, calibration, and testing of these models. This work adds to that data set by constraining the P-T-H2O conditions of primary melt extraction from two end-member subduction zones, a continental arc (Mexico) and an intraoceanic arc (Aleutians). We present our data in context with primitive melts found worldwide and with other experimental studies of melts produced from fertile and variably depleted mantle sources. Additionally, we compare our experimental results to melt compositions predicted by empirical and thermodynamic models. We used a piston-cylinder apparatus and employed an inverse approach in our experiments, constraining the permissible mantle residues with which our melts could be in equilibrium. We confirmed our inverse approach with forced saturation experiments at the P-T-H2O conditions of melt-mantle equilibration. Our experimental results show that a primitive, basaltic andesite melt (JR-28) from monogenetic cinder cone Volcan Jorullo (Central Mexico) last equilibrated with a harzburgite mantle residue at 1.2-1.4 GPa and 1150-1175°C with H2O contents in the range of 5.5-7 wt% H2O prior to ascent and eruption. Phase relations of a tholeiitic high-MgO basaltic melt (ID-16) from the Central Aleutians (Okmok) show the conditions of last equilibration with a fertile lherzolite mantle residue at shallower (1.2 GPa) but hotter (1275°C) conditions with approximately 2 wt% H2O. Given the estimated crustal thicknesses of these two regions, our data suggest that both samples equilibrate with mantle minerals just below the Moho. Recent viscosity dependent thermal models that account for slab geometry suggest that JR-28 melts last equilibrate with harzburgite in a cooler region of the mantle wedge. In contrast, ID-16 equilibrated with a fertile source near the hotter core of the mantle wedge. Our results support the hypothesis that lherzolite melting (wet or dry) produces essentially basaltic melts, whereas more Si-rich primitive melts require shallow hydrous melting of harzburgite or reequilibration of basaltic melts with harzburgite in the uppermost part of the wedge.

Crystallization and preliminary crystallographic analysis of the cellulose biosynthesis-related protein CMCax from Acetobacter xylinum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawano, Shin; Yasutake, Yoshiaki; Tajima, Kenji

2005-02-01

The cellulose biosynthesis-related protein CMCax from A. xylinum has been purified and crystallized. The crystals of CMCax belong to the primitive hexagonal space group P6{sub 1} or P6{sub 5}, with unit-cell parameters a = b = 89.1, c = 94.2 Å.

Proton Transports in Pure Liquid Water Characterized by Melted Ice Lattice Model

NASA Astrophysics Data System (ADS)

Jie, Binbin; Sah, Chihtang

Basic water properties have not been understood for 200 years. Our Melted Ice Lattice model accounts for the 2 basic properties of pure water, the ion product (pH) and mobilities. It has HCP primitive unit cells, each with 4H2O, based on the 1933 Bernal-Fowler model, verified by 1935 Pauling residual entropy theory of 1928-1935 Giauque experimental low temperature specific heat measurements. Our 2 ion species are point-mass protons p + and p-, for mass and electricity transport. Three protonic thermal activation energies are obtained from pH and p + and p- mobilities vs T (0-100OC). Proton transport is analyzed in 3 proton-phonon collision steps: proton detrapping by protonic phonon absorption, proton scattering by oxygenic (water) phonons, and proton trapping with protonic phonon emission. Distinction between Potential and Kinetic Energy Bands of protons (Fermions) and phonons (Bosons) is noted. Experimental protonic activation energies are the phonon energies given by the spring-mass vibration frequencies of lattice, wn = (kn/mn)1/2 . n is the proton-mass unit of the synchronized vibrating particles in the primitive unit cells.

Diagnostic Study of Tumor Characteristics in Patients With Ewing's Sarcoma

ClinicalTrials.gov

2013-06-20

Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells.

PubMed

Codispoti, Bruna; Rinaldo, Nicola; Chiarella, Emanuela; Lupia, Michela; Spoleti, Cristina Barbara; Marafioti, Maria Grazia; Aloisio, Annamaria; Scicchitano, Stefania; Giordano, Marco; Nappo, Giovanna; Lucchino, Valeria; Moore, Malcolm A S; Zhou, Pengbo; Mesuraca, Maria; Bond, Heather Mandy; Morrone, Giovanni

2017-07-04

Transplantation of hematopoietic stem cells (HSCs) is a well-established therapeutic approach for numerous disorders. HSCs are typically derived from bone marrow or peripheral blood after cytokine-induced mobilization. Umbilical cord blood (CB) represents an appealing alternative HSC source, but the small amounts of the individual CB units have limited its applications. The availability of strategies for safe ex vivo expansion of CB-derived HSCs (CB-HSCs) may allow to extend the use of these cells in adult patients and to avoid the risk of insufficient engraftment or delayed hematopoietic recovery.Here we describe a system for the ex vivo expansion of CB-HSCs based on their transient exposure to a recombinant TAT-BMI-1 chimeric protein. BMI-1 belongs to the Polycomb family of epigenetic modifiers and is recognized as a central regulator of HSC self-renewal. Recombinant TAT-BMI-1 produced in bacteria was able to enter the target cells via the HIV TAT-derived protein transduction peptide covalently attached to BMI-1, and conserved its biological activity. Treatment of CB-CD34+ cells for 3 days with repeated addition of 10 nM purified TAT-BMI-1 significantly enhanced total cell expansion as well as that of primitive hematopoietic progenitors in culture. Importantly, TAT-BMI-1-treated CB-CD34+ cells displayed a consistently higher rate of multi-lineage long-term repopulating activity in primary and secondary xenotransplants in immunocompromised mice. Thus, recombinant TAT-BMI-1 may represent a novel, effective reagent for ex vivo expansion of CB-HSC for therapeutic purposes.

Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells

PubMed Central

Codispoti, Bruna; Rinaldo, Nicola; Chiarella, Emanuela; Lupia, Michela; Spoleti, Cristina Barbara; Marafioti, Maria Grazia; Aloisio, Annamaria; Scicchitano, Stefania; Giordano, Marco; Nappo, Giovanna; Lucchino, Valeria; Moore, Malcolm A.S.; Zhou, Pengbo; Mesuraca, Maria

2017-01-01

Transplantation of hematopoietic stem cells (HSCs) is a well-established therapeutic approach for numerous disorders. HSCs are typically derived from bone marrow or peripheral blood after cytokine-induced mobilization. Umbilical cord blood (CB) represents an appealing alternative HSC source, but the small amounts of the individual CB units have limited its applications. The availability of strategies for safe ex vivo expansion of CB-derived HSCs (CB-HSCs) may allow to extend the use of these cells in adult patients and to avoid the risk of insufficient engraftment or delayed hematopoietic recovery. Here we describe a system for the ex vivo expansion of CB-HSCs based on their transient exposure to a recombinant TAT-BMI-1 chimeric protein. BMI-1 belongs to the Polycomb family of epigenetic modifiers and is recognized as a central regulator of HSC self-renewal. Recombinant TAT-BMI-1 produced in bacteria was able to enter the target cells via the HIV TAT-derived protein transduction peptide covalently attached to BMI-1, and conserved its biological activity. Treatment of CB-CD34+ cells for 3 days with repeated addition of 10 nM purified TAT-BMI-1 significantly enhanced total cell expansion as well as that of primitive hematopoietic progenitors in culture. Importantly, TAT-BMI-1-treated CB-CD34+ cells displayed a consistently higher rate of multi-lineage long-term repopulating activity in primary and secondary xenotransplants in immunocompromised mice. Thus, recombinant TAT-BMI-1 may represent a novel, effective reagent for ex vivo expansion of CB-HSC for therapeutic purposes. PMID:28187462

Collecting and Storing Biological Samples From Patients With Ewing Sarcoma

ClinicalTrials.gov

2017-12-11

Askin Tumor; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Absence of suppressor of cytokine signalling 3 reduces self-renewal and promotes differentiation in murine embryonic stem cells.

PubMed

Forrai, Ariel; Boyle, Kristy; Hart, Adam H; Hartley, Lynne; Rakar, Steven; Willson, Tracy A; Simpson, Ken M; Roberts, Andrew W; Alexander, Warren S; Voss, Anne K; Robb, Lorraine

2006-03-01

Leukemia inhibitory factor (LIF) is required to maintain pluripotency and permit self-renewal of murine embryonic stem (ES) cells. LIF binds to a receptor complex of LIFR-beta and gp130 and signals via the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, with signalling attenuated by suppressor of cytokine signalling (SOCS) proteins. Recent in vivo studies have highlighted the role of SOCS-3 in the negative regulation of signalling via gp130. To determine the role of SOCS-3 in ES cell biology, SOCS-3-null ES cell lines were generated. When cultured in LIF levels that sustain self-renewal of wild-type cells, SOCS-3-null ES cell lines exhibited less self-renewal and greater differentiation into primitive endoderm. The absence of SOCS-3 enhanced JAK-STAT and extracellular signal-related kinase 1/2 (ERK-1/2)-mitogen-activated protein kinase (MAPK) signal transduction via gp130, with higher levels of phosphorylated STAT-1, STAT-3, SH-2 domain-containing cytoplasmic protein tyrosine phosphatase 2 (SHP-2), and ERK-1/2 in steady state and in response to LIF stimulation. Attenuation of ERK signalling by the addition of MAPK/ERK kinase (MEK) inhibitors to SOCS-3-null ES cell cultures rescued the differentiation phenotype, but did not restore proliferation to wild-type levels. In summary, SOCS-3 plays a crucial role in the regulation of the LIF signalling pathway in murine ES cells. Its absence perturbs the balance between activation of the JAK-STAT and SHP-2-ERK-1/2-MAPK pathways, resulting in less self-renewal and a greater potential for differentiation into the primitive endoderm lineage.

The domestication of fire: the relationship between biomass fuel, fossil fuel and burns.

PubMed

Albertyn, R; Rode, H; Millar, A J W; Peck, M D

2012-09-01

Primitive man's discovery and use of fire had a tremendous impact on modern development. It changed lifestyles, and brought with it new fuel sources and cooking methods. It also introduced devastation, injury, pain, disfigurement, and loss of life, and the need to continuously develop management, training and prevention programs. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Compositional study of asteroids in the Erigone collisional family using visible spectroscopy at the 10.4m GTC

NASA Astrophysics Data System (ADS)

Morate, David; de León, Julia; De Prá, Mário; Licandro, Javier; Cabrera-Lavers, Antonio; Campins, Humberto; Pinilla-Alonso, Noemí; Alí-Lagoa, Víctor

2015-11-01

Asteroid families are formed by the fragments produced by the disruption of a common parent body (Bendjoya & Zappalà 2002). Primitive asteroids in the solar system are believed to have undergone less thermal processing than the S-complex asteroids. Thus, study of primitive asteroid families provides information about the solar system formation period. The Erigone collisional family, together with other three families (Polana, Clarissa and Sulamitis), are believed to be the origin of the two primitive Near-Earth asteroids that are the main targets of the NASA’s OSIRIS-REx ((101955) Bennu) and JAXA’s Hayabusa 2 ((162173) 1999 JU3) missions (Campins et al. 2010; Campins et al. 2013; Lauretta et al. 2010; Tsuda et al. 2013). These spacecrafts will visit the asteroids, and a sample of their surface material will be returned to Earth. Understanding of the families that are considered potential sources will enhance the scientific return of the missions. The main goal of the work presented here is to characterize the Erigone collisional family. Asteroid (163) Erigone has been classified as a primitive object (Bus 1999; Bus & Binzel 2002), and we expect the members of this family to be consistent with the spectral type of the parent body. We have obtained visible spectra (0.5-0.9 μm) for 101 members of the Erigone family, using the OSIRIS instrument at the 10.4m Gran Telescopio Canarias. We performed a taxonomical classification of these asteroids, finding that the number of primitive objects in our sample is in agreement with the hypothesis of a common parent body. In addition, we have found a significant fraction of asteroids in our sample that present evidences of aqueous alteration. Study of aqueous alterations is important, as it can give information on the heating processes of the early Solar System, and for the associated astrobiological implications (it has been suggested that the Earth’s present water supply was brought here by asteroids, instead of comets, in opposition to previous explanations (Morbidelli et al. 2000).

Europium and strontium anomalies in the MORB source mantle

NASA Astrophysics Data System (ADS)

Tang, Ming; McDonough, William F.; Ash, Richard D.

2017-01-01

Lower crustal recycling depletes the continental crust of Eu and Sr and returns Eu and Sr enriched materials into the mantle (e.g., Tang et al., 2015, Geology). To test the hypothesis that the MORB source mantle balances the Eu and Sr deficits in the continental crust, we carried out high precision Eu/Eu∗ and Sr/Sr∗ measurement for 72 MORB glasses with MgO >8.5% from the Pacific, Indian, and Atlantic mid-ocean ridges. MORB glasses with MgO ⩾ 9 wt.% have a mean Eu/Eu∗ of 1.025 ± 0.025 (2 σm, n = 46) and Sr/Sr∗ of 1.242 ± 0.093 (2 σm, n = 41) and these ratios are positively correlated. These samples show both positive and negative Eu and Sr anomalies, with no correlations between Eu/Eu∗ vs. MgO or Sr/Sr∗ vs. MgO, suggesting that the anomalies are not produced by plagioclase fractionation at MgO >9 wt.% and, thus, other processes must be responsible for generating the anomalies. We term these MORB samples primitive MORBs, as they record the melt Eu/Eu∗ and Sr/Sr∗ before plagioclase fractionation. Consequently, the mean oceanic crust, including cumulates, has a bulk Eu/Eu∗ of ∼1 and 20% Sr excess. Considering that divalent Sr and Eu(II) diffuse faster than trivalent Pr, Nd, Sm, and Gd, we evaluated this kinetic effect on Sm-Eu-Gd and Pr-Sr-Nd fractionations during spinel peridotite partial melting in the MORB source mantle. Our modeling shows that the correlated Eu and Sr anomalies seen in primitive MORBs may result from disequilibrium mantle melting. Melt fractions produced during early- and late-stage melting may carry positive and negative Eu and Sr anomalies, respectively, that overlap with the ranges documented in primitive MORBs. Because the net effect of disequilibrium melting is to produce partial melts with bulk positive Eu and Sr anomalies, the MORB source mantle must have Eu/Eu∗ < 1.025 ± 0.025 (2 σm) and Sr/Sr∗ < 1.242 ± 0.093 (2 σm). Although we cannot rule out the possibility that recycled lower continental crustal materials, which have positive Eu and Sr anomalies, are partially mixed into the upper mantle (i.e., MORB source region), a significant amount of this crustal component must have been sequestered into the deep mantle, as supported by the negative 206Pb/204Pb-Eu/Eu∗ and 206Pb/204Pb-Sr/Sr∗ correlations in ocean island basalts.

Oxaliplatin in Treating Young Patients With Recurrent Solid Tumors That Have Not Responded to Previous Treatment

ClinicalTrials.gov

2013-06-04

Childhood Central Nervous System Germ Cell Tumor; Childhood Extragonadal Germ Cell Tumor; Childhood Hepatoblastoma; Childhood Hepatocellular Carcinoma; Childhood High-grade Cerebral Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Malignant Ovarian Germ Cell Tumor; Childhood Malignant Testicular Germ Cell Tumor; Childhood Teratoma; Recurrent Adrenocortical Carcinoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Liver Cancer; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Rhabdomyosarcoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Colon Cancer; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Nasopharyngeal Cancer; Recurrent Neuroblastoma; Recurrent Osteosarcoma; Recurrent Rectal Cancer; Recurrent Renal Cell Cancer

Evaluating structural pattern recognition for handwritten math via primitive label graphs

NASA Astrophysics Data System (ADS)

Zanibbi, Richard; Mouchère, Harold; Viard-Gaudin, Christian

2013-01-01

Currently, structural pattern recognizer evaluations compare graphs of detected structure to target structures (i.e. ground truth) using recognition rates, recall and precision for object segmentation, classification and relationships. In document recognition, these target objects (e.g. symbols) are frequently comprised of multiple primitives (e.g. connected components, or strokes for online handwritten data), but current metrics do not characterize errors at the primitive level, from which object-level structure is obtained. Primitive label graphs are directed graphs defined over primitives and primitive pairs. We define new metrics obtained by Hamming distances over label graphs, which allow classification, segmentation and parsing errors to be characterized separately, or using a single measure. Recall and precision for detected objects may also be computed directly from label graphs. We illustrate the new metrics by comparing a new primitive-level evaluation to the symbol-level evaluation performed for the CROHME 2012 handwritten math recognition competition. A Python-based set of utilities for evaluating, visualizing and translating label graphs is publicly available.

[Primitive neuroectodermal tumor/Ewing's sarcoma of the penis in children: a case report and review of the literature].

PubMed

Zhang, Da-Wei; Jin, Mei; Zhou, Chun-Ju; Song, Hong-Cheng; Ma, Xiao-Li

2012-12-01

To investigate the clinical manifestations, pathological characteristics and treatment of primitive neuroectodermal tumor/Ewing's sarcoma (PNET/EWS) of the penis in children. We analyzed the clinical data of a case of PNET/EWS and reviewed relevant literature. The patient was a 5-year-old boy, admitted for penis swelling with pain for 11 months. Biopsy showed a small round cell tumor, CD99 positive by immunohistochemical staining, with EWS translocation by fluorescence in situ hybridization on molecular biological examination. The tumor was confirmed to be PNET/EWS of the penis, and disappeared after 45 weeks of chemotherapy and local radiotherapy. PNET/EWS of the penis is an extremely rare disease, with no specific clinical symptoms except penis enlargement with pain. Immunohistochemistry and molecular biological examination contribute to its diagnosis.

Identification of CD56 and CD57 by flow cytometry in Ewing's sarcoma or primitive neuroectodermal tumor.

PubMed

Gardner, L J; Polski, J M; Fallon, R; Dunphy, C H

1998-07-01

CD56 and CD57 are commonly considered as natural killer and neuroectodermal markers, but their expression has been identified in a wide spectrum of neoplasms including some cases of Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET). We report two cases of small, round blue cell tumor (SRBCT), in which flow cytometry immunophenotyping (FCI) detected strong expression of CD56 and CD57 (one case). Immunohistochemical staining with Leu-19 and Leu-7 confirmed the FI results. Although CD56 and CD57 expression is consistent with ES/PNET, it can be potentially misleading if results of FCI are interpreted in the absence of other findings. These cases suggest the utility of FCI in undifferentiated SRBCT. The literature on CD56 and CD57 expression in ES/PNET is reviewed and discussed.

Intracardiac heterotopia--mesenchymal and endodermal.

PubMed Central

Ariza, S; Rafel, E; Castillo, J A; Garcia-Canton, J A

1978-01-01

A case is reported of an intracardiac 'epithelial heterotopia' with a predominant mesenchymal component. This is thought to have resulted from the differentiation of aberrant primitive cell(s) displaced into the heart during its development. Though microscopically resembling a myxoma, this lesion is clearly distinguished by the presence of glandular structures. The myxoid component exhibited a startling invasiveness which resulted in occlusion of the superior vena cava, causing symptoms very early in life and death at the age of 6 months. Images PMID:637987

Transitional cell carcinoma of the retrorectal space arisen in tailgut cyst: a case report and review of the literature.

PubMed

Vinciguerra, Gian Luca Rampioni; Mercantini, Paolo; La Torre, Marco; Pilozzi, Emanuela; Ziparo, Vincenzo; Vecchione, Andrea

2014-05-01

Tailgut cysts, also known as retrorectal cystic hamartomas, are congenital lesions derived by an abnormal remnant of the postanal primitive hindgut, consisting of unilocular or multilocular cysts usually lined by squamous, transitional, or glandular epithelium. Malignant transformation is an uncommon event, and it mainly involves the neuroendocrine or glandular epithelium; other histotypes are sporadic. Here, we report, for the first time, the clinicopathological features of a transitional cell carcinoma that arose in a tailgut cyst.

South-to-north pyroxenite-peridotite source variation correlated with an OIB-type to arc-type enrichment of magmas from the Payenia backarc of the Andean Southern Volcanic Zone (SVZ)

NASA Astrophysics Data System (ADS)

Brandt, Frederik Ejvang; Holm, Paul Martin; Søager, Nina

2017-01-01

New high-precision minor element analysis of the most magnesian olivine cores (Fo85-88) in fifteen high-MgO (Mg#66-74) alkali basalts or trachybasalts from the Quaternary backarc volcanic province, Payenia, of the Andean Southern Volcanic Zone in Argentina displays a clear north-to-south decrease in Mn/Feol. This is interpreted as the transition from mainly peridotite-derived melts in the north to mainly pyroxenite-derived melts in the south. The peridotite-pyroxenite source variation correlates with a transition of rock compositions from arc-type to OIB-type trace element signatures, where samples from the central part of the province are intermediate. The southernmost rocks have, e.g., relatively low La/Nb, Th/Nb and Th/La ratios as well as high Nb/U, Ce/Pb, Ba/Th and Eu/Eu* = 1.08. The northern samples are characterized by the opposite and have Eu/Eu* down to 0.86. Several incompatible trace element ratios in the rocks correlate with Mn/Feol and also reflect mixing of two geochemically distinct mantle sources. The peridotite melt end-member carries an arc signature that cannot solely be explained by fluid enrichment since these melts have relatively low Eu/Eu*, Ba/Th and high Th/La ratios, which suggest a component of upper continental crust (UCC) in the metasomatizing agent of the northern mantle. However, the addition to the mantle source of crustal materials or varying oxidation state cannot explain the variation in Mn and Mn/Fe of the melts and olivines along Payenia. Instead, the correlation between Mn/Feol and whole-rock (wr) trace element compositions is evidence of two-component mixing of melts derived from peridotite mantle source enriched by slab fluids and UCC melts and a pyroxenite mantle source with an EM1-type trace element signature. Very low Ca/Fe ratios ( 1.1) in the olivines of the peridotite melt component and lower calculated partition coefficients for Ca in olivine for these samples are suggested to be caused by higher H2O contents in the magmas derived from subduction zone enriched mantle. Well-correlated Mn/Fe ratios in the wr and primitive olivines demonstrate that the Mn/Fewr of these basalts that only fractionated olivine and chromite reflects the Mn/Fe of the primitive melts and can be used as a proxy for the amount of pyroxenite melt in the magmas. Using Mn/Fewr for a large dataset of primitive Payenia rocks, we show that decreasing Mn/Fewr is correlated with decreasing Mn and increasing Zn/Mn as expected for pyroxenite melts.

Interpreting the universal phylogenetic tree

NASA Technical Reports Server (NTRS)

Woese, C. R.

2000-01-01

The universal phylogenetic tree not only spans all extant life, but its root and earliest branchings represent stages in the evolutionary process before modern cell types had come into being. The evolution of the cell is an interplay between vertically derived and horizontally acquired variation. Primitive cellular entities were necessarily simpler and more modular in design than are modern cells. Consequently, horizontal gene transfer early on was pervasive, dominating the evolutionary dynamic. The root of the universal phylogenetic tree represents the first stage in cellular evolution when the evolving cell became sufficiently integrated and stable to the erosive effects of horizontal gene transfer that true organismal lineages could exist.

Manipulation of immune system via immortal bone marrow stem cells.

PubMed

Ruedl, Christiane; Khameneh, Hanif Javanmard; Karjalainen, Klaus

2008-09-01

Extensive amplification of hematopoietic stem cells (HSCs) and their multipotent primitive progenitors (MPPs) in culture would greatly benefit not only clinical transplantation but also provide a potential tool to manipulate all cellular lineages derived from these cells for gene therapy and experimental purposes. Here, we demonstrate that mouse bone marrow cultures containing cells engineered to over-express NUP98-HOXB4 fusion protein support self-renewal of physiologically normal HSC and MPP for several weeks leading practically to their unlimited expansion. This allows time consuming and cumulative in vitro experimental manipulations without sacrificing their ability to differentiate in vivo or in vitro to any hematopoietic lineage.

Immune-related zinc finger gene ZFAT is an essential transcriptional regulator for hematopoietic differentiation in blood islands

PubMed Central

Tsunoda, Toshiyuki; Takashima, Yasuo; Tanaka, Yoko; Fujimoto, Takahiro; Doi, Keiko; Hirose, Yumiko; Koyanagi, Midori; Yoshida, Yasuhiro; Okamura, Tadashi; Kuroki, Masahide; Sasazuki, Takehiko; Shirasawa, Senji

2010-01-01

TAL1 plays pivotal roles in vascular and hematopoietic developments through the complex with LMO2 and GATA1. Hemangioblasts, which have a differentiation potential for both endothelial and hematopoietic lineages, arise in the primitive streak and migrate into the yolk sac to form blood islands, where primitive hematopoiesis occurs. ZFAT (a zinc-finger gene in autoimmune thyroid disease susceptibility region / an immune-related transcriptional regulator containing 18 C2H2-type zinc-finger domains and one AT-hook) was originally identified as an immune-related transcriptional regulator containing 18 C2H2-type zinc-finger domains and one AT-hook, and is highly conserved among species. ZFAT is thought to be a critical transcription factor involved in immune-regulation and apoptosis; however, developmental roles for ZFAT remain unknown. Here we show that Zfat-deficient (Zfat−/−) mice are embryonic-lethal, with impaired differentiation of hematopoietic progenitor cells in blood islands, where ZFAT is exactly expressed. Expression levels of Tal1, Lmo2, and Gata1 in Zfat−/− yolk sacs are much reduced compared with those of wild-type mice, and ChIP-PCR analysis revealed that ZFAT binds promoter regions for these genes in vivo. Furthermore, profound reduction in TAL1, LMO2, and GATA1 protein expressions are observed in Zfat−/− blood islands. Taken together, these results suggest that ZFAT is indispensable for mouse embryonic development and functions as a critical transcription factor for primitive hematopoiesis through direct-regulation of Tal1, Lmo2, and Gata1. Elucidation of ZFAT functions in hematopoiesis might lead to a better understanding of transcriptional networks in differentiation and cellular programs of hematopoietic lineage and provide useful information for applied medicine in stem cell therapy. PMID:20660741

Use of Optical Storage Devices as Shared Resources in Local Area Networks

DTIC Science & Technology

1989-09-01

13 3. SERVICE CALLS FOR MS-DOS CD-ROM EXTENSIONS . 14 4. MS-DOS PRIMITIVE GROUPS ....................... 15 5. RAM USAGE FOR VARIOUS LAN...17 2. Service Call Translation to DOS Primitives ............. 19 3. MS-DOS Device Drivers ............................. 21 4. MS-DOS/ROM...directed to I/O devices will be referred to as primitive instruction groups). These primitive instruction groups include keyboard, video, disk, serial

QCAPUF: QCA-based physically unclonable function as a hardware security primitive

NASA Astrophysics Data System (ADS)

Abutaleb, M. M.

2018-04-01

Physically unclonable functions (PUFs) are increasingly used as innovative security primitives to provide the hardware authentication and identification as well as the secret key generation based on unique and random variations in identically fabricated devices. Security and low power have appeared to become two crucial necessities to modern designs. As an emerging nanoelectronic technology, a quantum-dot cellular automata (QCA) can achieve ultra-low power consumption as well as an extremely small area for implementing digital designs. However, there are various classes of permanent defects that can happen during the manufacture of QCA devices. The recent extensive research has been focused on how to eliminate errors in QCA structures resulting from fabrication variances. By a completely different vision, to turn this disadvantage into an advantage, this paper presents a novel QCA-based PUF (QCAPUF) architecture to exploit the unique physical characteristics of fabricated QCA cells in order to produce different hardware fingerprint instances. This architecture is composed of proposed logic and interconnect blocks that have critical vulnerabilities and perform unexpected logical operations. The behaviour of QCAPUF is thoroughly analysed through physical relations and simulations. Results confirm that the proposed QCAPUF has state of the art PUF characteristics in the QCA technology. This paper will serve as a basis for further research into QCA-based hardware security primitives and applications.

Humic first, A new theory on the origin of life

NASA Astrophysics Data System (ADS)

Daei, Mohammad Ali; Daei, Manijeh

2016-04-01

In 1953, Miller &Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions1. In recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites2. These facts show simple organic molecules on early earth could be quite enough to start development of life. But, how? Many theorists have tried to explain how life emerged from non life, but failed2. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. Obviously, creation of a cell needed a qualified production line which had to be durable and active, can gather all biochemical ingredients, protect them from degradation, have catalyzing ability, provide numerous opportunities for interaction between basic molecules, and above all, have capability to react to different sources of energy. We are sure this perfect factory was available on primitive earth and is nothing except humic substance! At the moment, HS, are doing nearly all of these duties, among the others, under your feet in agricultural soils4. What are humic substances? According to IHSS definition "Humic substances (HS) are major components of the natural organic matter (NOM) in soil and water as well as in geological organic deposits such as lake sediments, peats, brown coals, and shales5." They come from polymerization of organic molecules, but looking at them like a simple aggregation of different organic molecules, is a huge mistake6! It seems they do not come together except for making a capable structure! HS are the first organic machinery which appeared in proplanetary disk, more than four billion years ago. Derived from simple inorganic molecules, humic substances construct a firm intermediate structure which connects none life to life. In other word, life road pass over the humic bridge. This does not mean that necessarily they had extra terrestrial origin. In fact Ziechman et al7, in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generate on early earth conditions by polymerizing simple organic molecules. Which evidences support our Ideas? 1- Suppose a wet land located in a warm area of primitive earth, covered with a layer of black humic materials, ready to action and reaction. Under this umbrella, basic molecules of life can interact freely and benefit from catalyzing and stimulating effects of HS. Amino and nucleic acid molecules may line up, grow, and develop mutually. Protein molecules can appear and do practices and before decaying a strand of nucleotides is ready to save their information and can rebuilt them for further practices. Thus, chemical evolution on a bed of humic acid can promote targeted, firmly and continuously towards a large network that be able to support a self replicating cell! We deliberately suggested, land and not the sea, as cradle of life. Because sodium, the most prevalent cation in oceans could not participate in primitive life, instead potassium played an important role. 2- There are strong evidences that show HS, really acted as the main elemental selector and even chairal selector for life on early earth. HS, show strong affinity and fast releasing tendency for macro nutrients (N, P, K).There is moderate affinity and releasing tendency for Ca, Mg, S. Also there is weak affinity and reluctance for liberating micronutrients. More interesting, HS generate insoluble compounds with nearly all toxic elements. As you see not only HS selected some and rejected other elements but also definite their proportions in the cell structure. 3- What is the reason of homochairality in living organism? As you know, none of previous theories in this field provided an easy explanation for this difficult and fundamental question. But, humic theory has a simple answer. Humic substances accepted some and rejected the other enantiomers, because their spatial structure dictate, as did so regarding elemental selection. References: 1- Miller, Stanly L." production of amino acid under possible primitive Earth conditions" Science 117:528.(may 1953) 2- Encyclopedia Britannica website "carbonaceous contrite" October 17, 2014 3- Shapiro, Robert " A simpler origin for life" Science American February 12 . 2007 4- Pettit, Robert, "organic matter, humus, humate, humic acid, fulvic acid humin: their importance in soil fertility and plant health" 5- International Humic Substances Society website, " What are humic substances" 6- Humic, Fulvic and microbial balance: organic soil conditioning, by William R. Jackson 1993, pag 165-167 7- Steinberg, Christian E.W "Ecology of humic substances in freshwater-determination from geochemistry to ecological niches" (2003)

Positron Emission Tomography Using Fluorine F 18 EF5 to Find Oxygen in Tumor Cells of Patients Who Are Undergoing Surgery or Biopsy for Newly Diagnosed Brain Tumors

ClinicalTrials.gov

2013-01-15

Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Central Nervous System Germ Cell Tumor; Adult Choroid Plexus Tumor; Adult Craniopharyngioma; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Grade III Meningioma; Adult Medulloblastoma; Adult Meningeal Hemangiopericytoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Pilocytic Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Subependymoma; Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Meningeal Melanocytoma

Method for concurrent execution of primitive operations by dynamically assigning operations based upon computational marked graph and availability of data

NASA Technical Reports Server (NTRS)

Mielke, Roland V. (Inventor); Stoughton, John W. (Inventor)

1990-01-01

Computationally complex primitive operations of an algorithm are executed concurrently in a plurality of functional units under the control of an assignment manager. The algorithm is preferably defined as a computationally marked graph contianing data status edges (paths) corresponding to each of the data flow edges. The assignment manager assigns primitive operations to the functional units and monitors completion of the primitive operations to determine data availability using the computational marked graph of the algorithm. All data accessing of the primitive operations is performed by the functional units independently of the assignment manager.

How to Spot a Primitive Black Hole

NASA Image and Video Library

2010-03-17

These two data plots from NASA Spitzer Space Telescope show a primitive supermassive black hole top compared to a typical one; usually, dust tori are missing and only gas disks are observed in primitive black holes.

Saguaro: A Distributed Operating System Based on Pools of Servers.

DTIC Science & Technology

1988-03-25

asynchronous message passing, multicast, and semaphores are supported. We have found this flexibility to be very useful for distributed programming. The...variety of communication primitives provided by SR has facilitated the research of Stella Atkins, who was a visiting professor at Arizona during Spring...data bits in a raw communication channel to help keep the source and destination synchronized , Psync explicitly embeds timing information drawn from the

Functional characterization of individual human hematopoietic stem cells cultured at limiting dilution on supportive marrow stromal layers.

PubMed Central

Sutherland, H J; Lansdorp, P M; Henkelman, D H; Eaves, A C; Eaves, C J

1990-01-01

A major goal of current hematopoiesis research is to develop in vitro methods suitable for the measurement and characterization of stem cells with long-term in vivo repopulating potential. Previous studies from several centers have suggested the presence in normal human or murine marrow of a population of very primitive cells that are biologically, physically, and pharmacologically different from cells detectable by short-term colony assays and that can give rise to the latter in long-term cultures (LTCs) containing a competent stromal cell layer. In this report, we show that such cultures can be used to provide a quantitative assay for human "LTC-initiating cells" based on an assessment of the number of clonogenic cells present after 5-8 weeks. Production of derivative clonogenic cells is shown to be absolutely dependent on the presence of a stromal cell feeder. When this requirement is met, the clonogenic cell output (determined by assessment of 5-week-old cultures) is linearly related to the input cell number over a wide range of cell concentrations. Using limiting dilution analysis techniques, we have established the frequency of LTC-initiating cells in normal human marrow to be approximately 1 per 2 X 10(4) cells and in a highly purified CD34-positive subpopulation to be approximately 1 per 50-100 cells. The proliferative capacity exhibited by individual LTC-initiating cells cultured under apparently identical culture conditions was found to be highly variable. Values for the number of clonogenic cells per LTC-initiating cell in 5-week-old cultures ranged from 1 to 30 (the average being 4) with similar levels being detected in positive 8-week-old cultures. Some LTC-initiating cells are multipotent as evidenced by their generation of erythroid as well as granulopoietic progeny. The availability of a system for quantitative analysis of the proliferative and differentiative behavior of this newly defined compartment of primitive human hematopoietic cells should facilitate future studies of specific genetic or microenvironmental parameters involved in the regulation of these cells. Images PMID:2333304

Versatility of `hemorheologic fitness' according to exercise intensity: emphasis on the "healthy primitive lifestyle"

NASA Astrophysics Data System (ADS)

Brun, Jean-Frédéric; Varlet-Marie, Emmanuelle; Chevance, Guillaume; Pollatz, Marion; Fedou, Christine; de Mauverger, Eric Raynaud

2014-05-01

We recently proposed a unifying hypothesis to reconcile unexpected findings in exercise hemorheology and the classical concepts of "hemorheologic fitness" and the "triphasic effects of exercise", based on the "healthy primitive lifestyle" paradigm. This paradigm assumes that evolution has selected genetic polymorphisms leading to insulin resistance as an adaptative strategy to cope with continuous low intensity physical activity and a special alimentation moderately high in protein, rich in low glycemic index carbohydrates, and poor in saturated fat. According to this protocol the true physiological picture would be that of an individual whose exercise and nutritional habits are close from this lifestyle, both sedentary subjects and trained athletes representing situations on the edge of this model. Unfortunately samples of people truly adhering to this ancestral lifestyle are hard to obtain. In order to address this picture we tried to compare databases obtained with our preceding published studies. As a model of the "healthy primitive lifestyle" we selected patients trained at low intensity (LI) and given an advice of protein intake around 1.2 g/kg/day. Results show a continuum for plasma viscosity which seems to be lower in athletes than LI-trained and even more sedentaries. When sedentary subjects become obese the most obvious characteristic is an increase in red blood cell (RBC) aggregation correlated to the size of fat stores. It is clear that 3 months of LI are not a perfect model of "healthy primitive lifestyle", but these data suggest that the most important effect of LI regular exercise is to decrease plasma viscosity and that sedentarity increases RBC aggregation mostly when it results in increased fat storage.

The geochemistry of primitive volcanic rocks of the Ankaratra volcanic complex, and source enrichment processes in the genesis of the Cenozoic magmatism in Madagascar

NASA Astrophysics Data System (ADS)

Melluso, L.; Cucciniello, C.; le Roex, A. P.; Morra, V.

2016-07-01

The Ankaratra volcanic complex in central Madagascar consists of lava flows, domes, scoria cones, tuff rings and maars of Cenozoic age that are scattered over 3800 km2. The mafic rocks include olivine-leucite-nephelinites, basanites, alkali basalts and hawaiites, and tholeiitic basalts. Primitive samples have high Mg# (>60), high Cr and Ni concentrations; their mantle-normalized patterns peak at Nb and Ba, have troughs at K, and smoothly decrease towards the least incompatible elements. The Ankaratra mafic rocks show small variation in Sr-Nd-Pb isotopic compositions (e.g., 87Sr/86Sr = 0.70377-0.70446, 143Nd/144Nd = 0.51273-0.51280, 206Pb/204Pb = 18.25-18.87). These isotopic values differ markedly from those of Cenozoic mafic lavas of northern Madagascar and the Comoro archipelago, typical Indian Ocean MORB and oceanic basalt end-members. The patterns of olivine nephelinitic magmas can be obtained through 3-10% partial melting of a mantle source that was enriched by a Ca-rich alkaline melt, and that contained garnet, carbonates and phlogopite. The patterns of tholeiitic basalts can be obtained after 10-12% partial melting of a source enriched with lower amounts of the same alkaline melt, in the spinel- (and possibly amphibole-) facies mantle, hence in volumes where carbonate is not a factor. The significant isotopic change from the northernmost volcanic rocks of Madagascar and those in the central part of the island implicates a distinct source heterogeneity, and ultimately assess the role of the continental lithospheric mantle as source region. The source of at least some volcanic rocks of the still active Comoro archipelago may have suffered the same time-integrated geochemical and isotopic evolution as that of the northern Madagascar volcanic rocks.

A key heterogeneous structure of fractal networks based on inverse renormalization scheme

NASA Astrophysics Data System (ADS)

Bai, Yanan; Huang, Ning; Sun, Lina

2018-06-01

Self-similarity property of complex networks was found by the application of renormalization group theory. Based on this theory, network topologies can be classified into universality classes in the space of configurations. In return, through inverse renormalization scheme, a given primitive structure can grow into a pure fractal network, then adding different types of shortcuts, it exhibits different characteristics of complex networks. However, the effect of primitive structure on networks structural property has received less attention. In this paper, we introduce a degree variance index to measure the dispersion of nodes degree in the primitive structure, and investigate the effect of the primitive structure on network structural property quantified by network efficiency. Numerical simulations and theoretical analysis show a primitive structure is a key heterogeneous structure of generated networks based on inverse renormalization scheme, whether or not adding shortcuts, and the network efficiency is positively correlated with degree variance of the primitive structure.

High-Dose Chemotherapy With or Without Total-Body Irradiation Followed by Autologous Stem Cell Transplant in Treating Patients With Hematologic Cancer or Solid Tumors

ClinicalTrials.gov

2018-04-05

Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Nasal Type Extranodal NK/T-cell Lymphoma; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Childhood Burkitt Lymphoma; Childhood Diffuse Large Cell Lymphoma; Childhood Immunoblastic Large Cell Lymphoma; Childhood Nasal Type Extranodal NK/T-cell Lymphoma; Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor (PNET); Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Hepatosplenic T-cell Lymphoma; Intraocular Lymphoma; Nodal Marginal Zone B-cell Lymphoma; Peripheral T-cell Lymphoma; Plasma Cell Neoplasm; Primary Systemic Amyloidosis; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Malignant Testicular Germ Cell Tumor; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Neuroblastoma; Recurrent Small Lymphocytic Lymphoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Multiple Myeloma; Regional Neuroblastoma; Splenic Marginal Zone Lymphoma; Testicular Lymphoma; Unspecified Adult Solid Tumor, Protocol Specific; Unspecified Childhood Solid Tumor, Protocol Specific; Waldenström Macroglobulinemia

Developmental characteristics of somatic cell hybrids between totipotent mouse teratocarcinoma and rat intestinal villus cells.

PubMed

van der Kamp, A W; Roza-de Jongh, E J; Houwen, R H; Magrane, G G; van Dongen, J M; Evans, M J

1984-09-01

Hybrids between mouse PCC4-azal teratocarcinoma cells and rat epithelial intestinal villus cells (PCI hybrids) are phenotypically teratocarcinoma cells. They express several teratocarcinoma-specific traits but do not express functions specific for differentiated cells. Tumour formation is partially or completely suppressed. Some of the hybrids show more extensive differentiation both in vitro and in vivo than the PCC4-azal parental line. The hybrids are capable of endoderm formation in monolayer cultures and of the formation of embryoid bodies in suspension cultures. Two of the tumour-forming hybrids generate derivatives of all three germ layers, whereas differentiation in the PCC4-azal tumours is restricted to the formation of primitive neuronal tissues.

A mutli-technique search for the most primitive CO chondrites

NASA Astrophysics Data System (ADS)

Alexander, C. M. O'D.; Greenwood, R. C.; Bowden, R.; Gibson, J. M.; Howard, K. T.; Franchi, I. A.

2018-01-01

As part of a study to identify the most primitive COs and to look for weakly altered CMs amongst the COs, we have conducted a multi-technique study of 16 Antarctic meteorites that had been classified as primitive COs. For this study, we have determined: (1) the bulk H, C and N abundances and isotopes, (2) bulk O isotopic compositions, (3) bulk modal mineralogies, and (4) for some selected samples the abundances and compositions of their insoluble organic matter (IOM). Two of the 16 meteorites do appear to be CMs - BUC 10943 seems to be a fairly typical CM, while MIL 090073 has probably been heated. Of the COs, DOM 08006 appears to be the most primitive CO identified to date and is quite distinct from the other members of its pairing group. The other COs fall into two groups that are less primitive than DOM 08006 and ALH 77307, the previously most primitive CO. The first group is composed of members of the DOM 08004 pairing group, except DOM 08006. The second group is composed of meteorites belonging to the MIL 03377 and MIL 07099 pairing groups. These two pairing groups should probably be combined. There is a dichotomy in the bulk O isotopes between the primitive (all Antarctic finds) and the more metamorphosed COs (mostly falls). This dichotomy can only partly be explained by the terrestrial weathering experienced by the primitive Antarctic samples. It seems that the more equilibrated samples interacted to a greater extent with 16O-poor material, probably water, than the more primitive meteorites.

Human Pluripotent Stem Cells Differentiated in Fully Defined Medium Generate Hematopoietic CD34+ and CD34− Progenitors with Distinct Characteristics

PubMed Central

Chicha, Laurie; Feki, Anis; Boni, Alessandro; Irion, Olivier; Hovatta, Outi; Jaconi, Marisa

2011-01-01

Background Differentiation of pluripotent stem cells in vitro provides a powerful means to investigate early developmental fates, including hematopoiesis. In particular, the use of a fully defined medium (FDM) would avoid biases induced by unidentified factors contained in serum, and would also allow key molecular mediators involved in such a process to be identified. Our goal was to induce in vitro, the differentiation of human embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) into morphologically and phenotypically mature leukocytes and erythrocytes, in the complete absence of serum and feeder cells. Methodology/Principal Findings ESC and iPSC were sequentially induced in liquid cultures for 4 days with bone morphogenic protein-4, and for 4 days with FLT3-ligand, stem cell factor, thrombopoietin and vascular endothelium growth factor. Cell differentiation status was investigated by both mRNA expression and FACS expression profiles. Cells were further sorted and assayed for their hematopoietic properties in colony-forming unit (CFU) assays. In liquid cultures, cells progressively down-modulated Oct-4 expression while a sizeable cell fraction expressed CD34 de novo. SCL/Tal1 and Runx1 transcripts were exclusively detected in CD34+ cells. In clonal assays, both ESC and iPSC-derived cells generated CFU, albeit with a 150-fold lower efficacy than cord blood (CB) CD34+ cells. ESC-derived CD34+ cells generated myeloid and fully hemoglobinized erythroid cells whereas CD34− cells almost exclusively generated small erythroid colonies. Both ESC and iPSC-derived erythroid cells expressed embryonic and fetal globins but were unable to synthesize adult β-globin in contrast with CB cells, suggesting that they had differentiated from primitive rather than from definitive hematopoietic progenitors. Conclusions/Significance Short-term, animal protein-free culture conditions are sufficient to sustain the differentiation of human ESC and iPSC into primitive hematopoietic progenitors, which, in turn, produce more mature blood cell types. However, additional factors have yet to be identified to allow their differentiation into definitive erythroid cultures. PMID:21364915

Human pluripotent stem cells differentiated in fully defined medium generate hematopoietic CD34- and CD34+ progenitors with distinct characteristics.

PubMed

Chicha, Laurie; Feki, Anis; Boni, Alessandro; Irion, Olivier; Hovatta, Outi; Jaconi, Marisa

2011-02-25

Differentiation of pluripotent stem cells in vitro provides a powerful means to investigate early developmental fates, including hematopoiesis. In particular, the use of a fully defined medium (FDM) would avoid biases induced by unidentified factors contained in serum, and would also allow key molecular mediators involved in such a process to be identified. Our goal was to induce in vitro, the differentiation of human embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) into morphologically and phenotypically mature leukocytes and erythrocytes, in the complete absence of serum and feeder cells. ESC and iPSC were sequentially induced in liquid cultures for 4 days with bone morphogenic protein-4, and for 4 days with FLT3-ligand, stem cell factor, thrombopoietin and vascular endothelium growth factor. Cell differentiation status was investigated by both mRNA expression and FACS expression profiles. Cells were further sorted and assayed for their hematopoietic properties in colony-forming unit (CFU) assays. In liquid cultures, cells progressively down-modulated Oct-4 expression while a sizeable cell fraction expressed CD34 de novo. SCL/Tal1 and Runx1 transcripts were exclusively detected in CD34(+) cells. In clonal assays, both ESC and iPSC-derived cells generated CFU, albeit with a 150-fold lower efficacy than cord blood (CB) CD34(+) cells. ESC-derived CD34(+) cells generated myeloid and fully hemoglobinized erythroid cells whereas CD34(-) cells almost exclusively generated small erythroid colonies. Both ESC and iPSC-derived erythroid cells expressed embryonic and fetal globins but were unable to synthesize adult β-globin in contrast with CB cells, suggesting that they had differentiated from primitive rather than from definitive hematopoietic progenitors. Short-term, animal protein-free culture conditions are sufficient to sustain the differentiation of human ESC and iPSC into primitive hematopoietic progenitors, which, in turn, produce more mature blood cell types. However, additional factors have yet to be identified to allow their differentiation into definitive erythroid cultures.

A monoclonal antibody inhibits calcium accumulation and skeleton formation in cultured embryonic cells of the sea urchin.

PubMed

Carson, D D; Farach, M C; Earles, D S; Decker, G L; Lennarz, W J

1985-06-01

The assembly of the spicules (primitive skeleton) of the sea urchin embryo is being studied in primary mesenchyme cells cultured in vitro. A monoclonal antibody (1223) has been prepared that inhibits the deposition of CaCO3 into the spicules. This antibody reacts with a 130,000 Mr cell-surface protein that is concentrated on the surface of approximately 5% of the cells of dissociated gastrula stage embryos. When primary mesenchyme cells in the embryo or cells cultured in vitro are examined, the 1223 antigen is detected on the surface of the cells and on the extracellular material associated with the spicule. We conclude that the 1223 antibody recognizes a cell-surface protein that plays an essential role in spicule formation.

Spontaneous encapsulation and concentration of biological macromolecules in liposomes: an intriguing phenomenon and its relevance in origins of life.

PubMed

de Souza, Tereza Pereira; Fahr, Alfred; Luisi, Pier Luigi; Stano, Pasquale

2014-12-01

One of the main open questions in origin of life research focuses on the formation, by self-organization, of primitive cells composed by macromolecular compounds enclosed within a semi-permeable membrane. A successful experimental strategy for studying the emergence and the properties of primitive cells relies on a synthetic biology approach, consisting in the laboratory assembly of cell models of minimal complexity (semi-synthetic minimal cells). Despite the recent advancements in the construction and characterization of synthetic cells, an important physical aspect related to their formation is still not well known, namely, the mechanism of solute entrapment inside liposomes (in particular, the entrapment of macromolecules). In the past years, we have investigated this phenomenon and here we shortly review our experimental results. We show how the detailed cryo-transmission electron microscopy analyses of liposome populations created in the presence of ferritin (taken as model protein) or ribosomes have revealed that a small fraction of liposomes contains a high number of solutes, against statistical expectations. The local (intra-liposomal) macromolecule concentration in these liposomes largely exceeds the bulk concentration. A similar behaviour is observed when multi-molecular reaction mixtures are used, whereby the reactions occur effectively only inside those liposomes that have entrapped high number of molecules. If similar mechanisms operated in early times, these intriguing results support a scenario whereby the formation of lipid compartments plays an important role in concentrating the components of proto-metabolic systems-in addition to their well-known functions of confinement and protection.

Origin Of The Near-earth Asteroid Phaethon And The Geminids Meteor Shower

NASA Astrophysics Data System (ADS)

de Leon, Julia; Campins, H.; Tsiganis, K.; Morbidelli, A.; Licandro, J.

2010-10-01

Asteroid (3200) Phaethon is a remarkable Near Earth Asteroid (NEA). It was the first asteroid associated with a meteor shower, namely the Geminid stream1. Phaethon's unusual orbit has a high inclination and a very low perihelion distance (0.14 AU). Its reflectance spectrum suggests a connection with primitive meteorites, best fitting with CI/CM carbonaceous chondrites2, aqueously altered and rich in hydrated silicates. However, its origin is not well determined. Recent studies suggest a connection with the population of main-belt comets3, classifying Phaethon as an activated asteroid. Here we show that the most likely source of Phaethon and the Geminids is the asteroid (2) Pallas, one of the largest asteroids in the main belt, which is surrounded by a collisional family, containing several Phaethon-sized objects. Pallas’ highly inclined orbit and surface composition, also primitive and with evidence of hydration4, support this connection. Our analysis reveals a striking similarity between Phaethon's visual spectrum and those of Pallas family members. Moreover, our numerical simulations show the existence of a robust dynamical pathway, connecting the orbital neighborhood of Pallas with that of Phaethon. In this respect, the Pallas family may constitute a source of primitive NEAs. (The author gratefully acknowledges support from the Spanish "Ministerio de Ciencia e Innovación" projects AYA2005-07808-C03-02 and AYA2008-06202-C03-02.) References 1. Whipple, F. L. 1983, IAU Circular, 3881 2. Licandro, J., Campins, H., Mothe-Diniz, T., Pinilla-Alonso, N. & de Leon, J. 2007, Astron. Astrophys. 461, 751-757 3. Hsieh, H. H., & Jewitt, D. 2006, Science, 312, 561-563 4. Rivkin, A. S., Howell, E. S., Vilas, F. & Lebofsky, L. A. in Asteroids III (eds Bottke, W. F., Cellino, A., Paolicchi, P. & Binzel, R. P.) 235-253 (Univ. Arizona Press, 2002).

Dynamic primitives in the control of locomotion.

PubMed

Hogan, Neville; Sternad, Dagmar

2013-01-01

Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term "rhythmic" may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered.

A simple physical mechanism enables homeostasis in primitive cells

NASA Astrophysics Data System (ADS)

Engelhart, Aaron E.; Adamala, Katarzyna P.; Szostak, Jack W.

2016-05-01

The emergence of homeostatic mechanisms that enable maintenance of an intracellular steady state during growth was critical to the advent of cellular life. Here, we show that concentration-dependent reversible binding of short oligonucleotides, of both specific and random sequence, can modulate ribozyme activity. In both cases, catalysis is inhibited at high concentrations, and dilution activates the ribozyme via inhibitor dissociation, thus maintaining near-constant ribozyme specific activity throughout protocell growth. To mimic the result of RNA synthesis within non-growing protocells, we co-encapsulated high concentrations of ribozyme and oligonucleotides within fatty acid vesicles, and ribozyme activity was inhibited. Following vesicle growth, the resulting internal dilution produced ribozyme activation. This simple physical system enables a primitive homeostatic behaviour: the maintenance of constant ribozyme activity per unit volume during protocell volume changes. We suggest that such systems, wherein short oligonucleotides reversibly inhibit functional RNAs, could have preceded sophisticated modern RNA regulatory mechanisms, such as those involving miRNAs.

How many theories for the origin of /proto/life

NASA Technical Reports Server (NTRS)

Fox, S. W.

1980-01-01

The sequence of primordial chemical events leading to contemporary metabolism is considered, taking into account primordial reactants, amino acids, proteinoid, protocells, ATP, polynucleotides, and protein. The right kind of matter, thermal copolyamino acids, can organize itself into cell-like structures, in the absence of discrete lipid, when triggered to do so by water. Another unpredicted result of examination of the microsystems formed was the step-by-step realization that the component processes of a primitive form of replication were latent in the proteinoid microsystems. At the present time, four modes of primitive replication of proteinoid microsystems have been identified, plus one that has the appearance of protosexual reproduction. Two main conceptual pathways have received attention. One is the proteinoid theory, derived from experiments. The other is the DNA-first theory, for which attempts at conceptual construction and experimental support continue to be sought.

The origin and early evolution of life on earth

NASA Technical Reports Server (NTRS)

Oro, J.; Miller, Stanley L.; Lazcano, Antonio

1990-01-01

Results of the studies that have provided insights into the cosmic and primitive earth environments are reviewed with emphasis on those environments in which life is thought to have originated. The evidence bearing on the antiquity of life on the earth and the prebiotic significance of organic compounds found in interstellar clouds and in primitive solar-system bodies such as comets, dark asteroids, and carbonaceous chondrites are assessed. The environmental models of the Hadean and early Archean earth are discussed, as well as the prebiotic formation of organic monomers and polymers essential to life. The processes that may have led to the appearance in the Archean of the first cells are considered, and possible effects of these processes on the early steps of biological evolution are analyzed. The significance of these results to the study of the distribution of life in the universe is evaluated.

Inhibiting Low-Frequency Vibrations Explains Exceptionally High Electron Mobility in 2,5-Difluoro-7,7,8,8-tetracyanoquinodimethane (F2-TCNQ) Single Crystals.

PubMed

Chernyshov, Ivan Yu; Vener, Mikhail V; Feldman, Elizaveta V; Paraschuk, Dmitry Yu; Sosorev, Andrey Yu

2017-07-06

Organic electronics requires materials with high charge mobility. Despite decades of intensive research, charge transport in high-mobility organic semiconductors has not been well understood. In this Letter, we address the physical mechanism underlying the exceptionally high band-like electron mobility in F 2 -TCNQ (2,5-difluoro-7,7,8,8-tetracyanoquinodimethane) single crystals among a crystal family of similar compounds F n -TCNQ (n = 0, 2, 4) using a combined experimental and theoretical approach. While electron transfer integrals and reorganization energies did not show outstanding features for F 2 -TCNQ, Raman spectroscopy and solid-state DFT indicated that the frequency of the lowest vibrational mode is nearly twice higher in the F 2 -TCNQ crystal than in TCNQ and F 4 -TCNQ. This phenomenon is explained by the specific packing motif of F 2 -TCNQ with only one molecule per primitive cell so that electron-phonon interaction decreases and the electron mobility increases. We anticipate that our findings will encourage investigators for the search and design of organic semiconductors with one molecule per primitive cell and/or the poor low-frequency vibrational spectrum.

Breaking the rules? X-ray examination of hematopoietic stem cell grafts at international airports.

PubMed

Petzer, Andreas L; Speth, Hans-Georg; Hoflehner, Elisabeth; Clausen, Johannes; Nachbaur, David; Gastl, Günther; Gunsilius, Eberhard

2002-06-15

Hematopoietic stem cell grafts from unrelated donors are commonly transported by aircraft. They must not be subjected to x-rays during security checks, which may cause inconvenient discussions between the courier and the airport security staff. We exposed hematopoietic stem cells from mobilized peripheral blood to a widely used x-ray hand-luggage control system. Cell viability as well as growth in vitro of mature progenitor cells (colony-forming cells), primitive progenitor cells (long-term culture-initiating cells), and lymphocytes were not altered even after 10 passages through the hand-luggage control system. Thus, repeated exposure to the low radiation dose of hand-luggage control systems (1.5 +/- 0.6 microSv per exposure) seems to be harmless for hematopoietic stem cells, which should simplify the international transport of stem cell grafts.

Fundamental physical theories: Mathematical structures grounded on a primitive ontology

NASA Astrophysics Data System (ADS)

Allori, Valia

In my dissertation I analyze the structure of fundamental physical theories. I start with an analysis of what an adequate primitive ontology is, discussing the measurement problem in quantum mechanics and theirs solutions. It is commonly said that these theories have little in common. I argue instead that the moral of the measurement problem is that the wave function cannot represent physical objects and a common structure between these solutions can be recognized: each of them is about a clear three-dimensional primitive ontology that evolves according to a law determined by the wave function. The primitive ontology is what matter is made of while the wave function tells the matter how to move. One might think that what is important in the notion of primitive ontology is their three-dimensionality. If so, in a theory like classical electrodynamics electromagnetic fields would be part of the primitive ontology. I argue that, reflecting on what the purpose of a fundamental physical theory is, namely to explain the behavior of objects in three-dimensional space, one can recognize that a fundamental physical theory has a particular architecture. If so, electromagnetic fields play a different role in the theory than the particles and therefore should be considered, like the wave function, as part of the law. Therefore, we can characterize the general structure of a fundamental physical theory as a mathematical structure grounded on a primitive ontology. I explore this idea to better understand theories like classical mechanics and relativity, emphasizing that primitive ontology is crucial in the process of building new theories, being fundamental in identifying the symmetries. Finally, I analyze what it means to explain the word around us in terms of the notion of primitive ontology in the case of regularities of statistical character. Here is where the notion of typicality comes into play: we have explained a phenomenon if the typical histories of the primitive ontology give rise to the statistical regularities we observe.

A novel class sensitive hashing technique for large-scale content-based remote sensing image retrieval

NASA Astrophysics Data System (ADS)

Reato, Thomas; Demir, Begüm; Bruzzone, Lorenzo

2017-10-01

This paper presents a novel class sensitive hashing technique in the framework of large-scale content-based remote sensing (RS) image retrieval. The proposed technique aims at representing each image with multi-hash codes, each of which corresponds to a primitive (i.e., land cover class) present in the image. To this end, the proposed method consists of a three-steps algorithm. The first step is devoted to characterize each image by primitive class descriptors. These descriptors are obtained through a supervised approach, which initially extracts the image regions and their descriptors that are then associated with primitives present in the images. This step requires a set of annotated training regions to define primitive classes. A correspondence between the regions of an image and the primitive classes is built based on the probability of each primitive class to be present at each region. All the regions belonging to the specific primitive class with a probability higher than a given threshold are highly representative of that class. Thus, the average value of the descriptors of these regions is used to characterize that primitive. In the second step, the descriptors of primitive classes are transformed into multi-hash codes to represent each image. This is achieved by adapting the kernel-based supervised locality sensitive hashing method to multi-code hashing problems. The first two steps of the proposed technique, unlike the standard hashing methods, allow one to represent each image by a set of primitive class sensitive descriptors and their hash codes. Then, in the last step, the images in the archive that are very similar to a query image are retrieved based on a multi-hash-code-matching scheme. Experimental results obtained on an archive of aerial images confirm the effectiveness of the proposed technique in terms of retrieval accuracy when compared to the standard hashing methods.

Learning multivariate distributions by competitive assembly of marginals.

PubMed

Sánchez-Vega, Francisco; Younes, Laurent; Geman, Donald

2013-02-01

We present a new framework for learning high-dimensional multivariate probability distributions from estimated marginals. The approach is motivated by compositional models and Bayesian networks, and designed to adapt to small sample sizes. We start with a large, overlapping set of elementary statistical building blocks, or "primitives," which are low-dimensional marginal distributions learned from data. Each variable may appear in many primitives. Subsets of primitives are combined in a Lego-like fashion to construct a probabilistic graphical model; only a small fraction of the primitives will participate in any valid construction. Since primitives can be precomputed, parameter estimation and structure search are separated. Model complexity is controlled by strong biases; we adapt the primitives to the amount of training data and impose rules which restrict the merging of them into allowable compositions. The likelihood of the data decomposes into a sum of local gains, one for each primitive in the final structure. We focus on a specific subclass of networks which are binary forests. Structure optimization corresponds to an integer linear program and the maximizing composition can be computed for reasonably large numbers of variables. Performance is evaluated using both synthetic data and real datasets from natural language processing and computational biology.

Cometary dust: the diversity of primitive refractory grains

PubMed Central

Ishii, H. A.

2017-01-01

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta), as well as through remote sensing (Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium–aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554979

Unravelling the mystery of stem/progenitor cells in human breast milk.

PubMed

Fan, Yiping; Chong, Yap Seng; Choolani, Mahesh A; Cregan, Mark D; Chan, Jerry K Y

2010-12-28

Mammary stem cells have been extensively studied as a system to delineate the pathogenesis and treatment of breast cancer. However, research on mammary stem cells requires tissue biopsies which limit the quantity of samples available. We have previously identified putative mammary stem cells in human breast milk, and here, we further characterised the cellular component of human breast milk. We identified markers associated with haemopoietic, mesenchymal and neuro-epithelial lineages in the cellular component of human breast milk. We found 2.6 ± 0.8% (mean ± SEM) and 0.7 ± 0.2% of the whole cell population (WCP) were found to be CD133+ and CD34+ respectively, 27.8 ± 9.1% of the WCP to be positive for Stro-1 through flow-cytometry. Expressions of neuro-ectodermal stem cell markers such as nestin and cytokeratin 5 were found through reverse-transcription polymerase chain reaction (RT-PCR), and in 4.17 ± 0.2% and 0.9 ± 0.2% of the WCP on flow-cytometry. We also established the presence of a side-population (SP) (1.8 ± 0.4% of WCP) as well as CD133+ cells (1.7 ± 0.5% of the WCP). Characterisation of the sorted SP and non-SP, CD133+ and CD133- cells carried out showed enrichment of CD326 (EPCAM) in the SP cells (50.6 ± 8.6 vs 18.1 ± 6.0, P-value  = 0.02). However, culture in a wide range of in vitro conditions revealed the atypical behaviour of stem/progenitor cells in human breast milk; in that if they are present, they do not respond to established culture protocols of stem/progenitor cells. The identification of primitive cell types within human breast milk may provide a non-invasive source of relevant mammary cells for a wide-range of applications; even the possibility of banking one's own stem cell for every breastfeeding woman.

Unravelling the Mystery of Stem/Progenitor Cells in Human Breast Milk

PubMed Central

Fan, Yiping; Chong, Yap Seng; Choolani, Mahesh A.; Cregan, Mark D.; Chan, Jerry K. Y.

2010-01-01

Background Mammary stem cells have been extensively studied as a system to delineate the pathogenesis and treatment of breast cancer. However, research on mammary stem cells requires tissue biopsies which limit the quantity of samples available. We have previously identified putative mammary stem cells in human breast milk, and here, we further characterised the cellular component of human breast milk. Methodology/Principal Findings We identified markers associated with haemopoietic, mesenchymal and neuro-epithelial lineages in the cellular component of human breast milk. We found 2.6±0.8% (mean±SEM) and 0.7±0.2% of the whole cell population (WCP) were found to be CD133+ and CD34+ respectively, 27.8±9.1% of the WCP to be positive for Stro-1 through flow-cytometry. Expressions of neuro-ectodermal stem cell markers such as nestin and cytokeratin 5 were found through reverse-transcription polymerase chain reaction (RT-PCR), and in 4.17±0.2% and 0.9±0.2% of the WCP on flow-cytometry. We also established the presence of a side-population (SP) (1.8±0.4% of WCP) as well as CD133+ cells (1.7±0.5% of the WCP). Characterisation of the sorted SP and non-SP, CD133+ and CD133- cells carried out showed enrichment of CD326 (EPCAM) in the SP cells (50.6±8.6 vs 18.1±6.0, P-value  = 0.02). However, culture in a wide range of in vitro conditions revealed the atypical behaviour of stem/progenitor cells in human breast milk; in that if they are present, they do not respond to established culture protocols of stem/progenitor cells. Conclusions/Significance The identification of primitive cell types within human breast milk may provide a non-invasive source of relevant mammary cells for a wide-range of applications; even the possibility of banking one's own stem cell for every breastfeeding woman. PMID:21203434

Fitting primitive shapes in point clouds: a practical approach to improve autonomous underwater grasp specification of unknown objects

NASA Astrophysics Data System (ADS)

Fornas, D.; Sales, J.; Peñalver, A.; Pérez, J.; Fernández, J. J.; Marín, R.; Sanz, P. J.

2016-03-01

This article presents research on the subject of autonomous underwater robot manipulation. Ongoing research in underwater robotics intends to increase the autonomy of intervention operations that require physical interaction in order to achieve social benefits in fields such as archaeology or biology that cannot afford the expenses of costly underwater operations using remote operated vehicles. Autonomous grasping is still a very challenging skill, especially in underwater environments, with highly unstructured scenarios, limited availability of sensors and adverse conditions that affect the robot perception and control systems. To tackle these issues, we propose the use of vision and segmentation techniques that aim to improve the specification of grasping operations on underwater primitive shaped objects. Several sources of stereo information are used to gather 3D information in order to obtain a model of the object. Using a RANSAC segmentation algorithm, the model parameters are estimated and a set of feasible grasps are computed. This approach is validated in both simulated and real underwater scenarios.

Current status of the prebiotic synthesis of small molecules

NASA Technical Reports Server (NTRS)

Miller, Stanley L.

1986-01-01

Experiments designed to simulate conditions on the primitive earth and to demonstrate how the organic compounds that made up the first living organisms were synthesized are described. Simulated atmospheres with CH4, N2, NH3, and H2O were found to be most effective for synthesis of small prebiotic molecules, although atmospheres with H2, CO, N2, and H2O, and with H2, CO2, N2, and H2O also give good yields of organic compounds provided the H2/CO and H2/CO2 ratios are above 1 and 2, respectively. The spark discharge (which is a good source of HCN) and UV light are also important. Reasonable prebiotic syntheses were worked out for the amino acids that occur in proteins (with the exception of lysine, arginine, and histidine), and for purines, pyrimidines, sugars, and nicotinic acid. Many of the molecules that have been produced in these simulated primitive-earth experiments are found in carbonaceous chondrites.

Rb-Sr Isotopic Studies Of Antarctic Lherzolitic Shergottite Yamato 984028

NASA Technical Reports Server (NTRS)

Shih, C.-Y.; Nyquist, L. E.; Reese, Y.; Misawa, K.

2009-01-01

Yamato 984028 is a Martian meteorite found in the Yamato Mountains of Antarctica. It is classified as a lherzolitic shergottite and petrographically resembles several other lherzolitic shergottites, i.e. ALHA 77005, LEW 88516, Y-793605 and Y-000027/47/97 [e.g. 2-5]. These meteorites have similarly young crystallization ages (152-185 Ma) as enriched basaltic shergottites (157-203 Ma), but have very different ejection ages (approximately 4 Ma vs. approximately 2.5 Ma), thus they came from different martian target crater areas. Lherzolitic shergottites have mg-values approximately 0.70 and represent the most mafic olivine-pyroxene cumulates. Their parental magmas were melts derived probably from the primitive Martian mantle. Here we present Rb-Sr isotopic data for Y-984028 and compare these data with those obtained from other lherzolitic and olivine-phyric basaltic shergottites to better understand the isotopic characteristics of their primitive mantle source regions. Corresponding Sm-Nd analyses for Y-984028 are in progress.

Ar-Ar and I-Xe Ages of Caddo County and Thermal History of IAB Iron Meteorites

NASA Technical Reports Server (NTRS)

Bogard, Donald D.; Garrison, Daniel H.; Takeda, Hiroshi

2005-01-01

Inclusions in IAB iron meteorites include non-chondritic silicate and those with more primitive chondritic silicate composition. Coarse-grained gabbroic material rich in plagioclase and diopside occurs in the Caddo County IAB iron meteorite and represents a new type of chemically differentiated, extra-terrestrial, andesitic silicate. Other parts of Caddo contain mostly andesitic material. Caddo thus exhibits petrologic characteristics of parent body metamorphism of a chondrite-like parent and inhomogeneous segregation of melts. Proposed IAB formation models include parent body partial melting and fractional crystallization or incomplete differentiation due to internal heat sources, and impact/induced melting and mixing. Benedix et al. prefer a hybrid model whereby the IAB parent body largely melted, then underwent collisional breakup, partial mixing of phases, and reassembly. Most reported 129I- Xe-129 ages of IABs are greater than 4.56 Gyr and a few are greater than or = 4.567 Gyr. These oldest ages exceed the 4.567 Gyr Pb-Pb age of Ca, Al-rich inclusions in primitive meteorites,

Age-related Deterioration of Hematopoietic Stem Cells.

PubMed

Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

2008-11-01

Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the effects of aging on stem cell functions are inconclusive. Here we review the age-related properties of hematopoietic stem cells in terms of intrinsic and extrinsic alterations, proliferative potential, signaling molecules, telomere and telomerase, senescence and cancer issues, regenerative potential and other indications of stem cell aging are discussed in detail.

Age-related Deterioration of Hematopoietic Stem Cells

PubMed Central

Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

2008-01-01

Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the effects of aging on stem cell functions are inconclusive. Here we review the age-related properties of hematopoietic stem cells in terms of intrinsic and extrinsic alterations, proliferative potential, signaling molecules, telomere and telomerase, senescence and cancer issues, regenerative potential and other indications of stem cell aging are discussed in detail. PMID:24855509

Round cell sarcomas beyond Ewing: emerging entities.

PubMed

Antonescu, Cristina

2014-01-01

Primitive small blue round cell tumours (SBRCT) of childhood and young adults have been problematic to diagnose and classify. Diagnosis is also complicated in cases with atypical morphology, aberrant immunoprofiles and unusual clinical presentations. Even with the increased use of ancillary techniques in archival material, such as immunohistochemistry and molecular/genetic methods, a proportion of these tumours cannot be subclassified into specific histological types. A subset of tumours resembling microscopically the Ewing sarcoma family of tumours (EFT), being composed of primitive small round cells and occurring in paediatric or young adult age groups, remain unclassified, being negative for EWSR1, SS18(SYT), DDIT3(CHOP) and FOXO1(FKHR) gene rearrangements by FISH/RT-PCR. A small number of cases sharing the undifferentiated EFT appearance have been characterized recently carrying BCOR-CCNB3 or CIC-DUX4 fusions. However, based on the somewhat limited number of cases, it remains unclear if these newly defined genetic entities belong to any of the pre-existing clinicopathological disorders or represent altogether novel conditions. This review presents the latest molecular findings related to these SBRCTs, beyond the common EWSR1-ETS fusions. Specific attention has been paid to morphological features not associated typically with classic EFT, and the value of ancillary tests that can be applied when dealing with EWSR1-negative SBRCTs is discussed. © 2013 John Wiley & Sons Ltd.

Basic primitives for molecular diagram sketching

PubMed Central

2010-01-01

A collection of primitive operations for molecular diagram sketching has been developed. These primitives compose a concise set of operations which can be used to construct publication-quality 2 D coordinates for molecular structures using a bare minimum of input bandwidth. The input requirements for each primitive consist of a small number of discrete choices, which means that these primitives can be used to form the basis of a user interface which does not require an accurate pointing device. This is particularly relevant to software designed for contemporary mobile platforms. The reduction of input bandwidth is accomplished by using algorithmic methods for anticipating probable geometries during the sketching process, and by intelligent use of template grafting. The algorithms and their uses are described in detail. PMID:20923555

Gas Phase Chemistry and Molecular Complexity: How Far Do They Go?

NASA Astrophysics Data System (ADS)

Balucani, Nadia

2016-07-01

The accumulation of organic molecules of increasing complexity is believed to be an important step toward the emergence of life. But how massive organic synthesis could occur in primitive Earth, i.e. a water-dominated environment, is a matter of debate. Two alternative theories have been suggested so far: endogenous and exogenous synthesis. In the first theory, the synthesis of simple organic molecules having a strong prebiotic potential (simple prebiotic molecules SPMs, such as H2CO, HCN, HC3N, NH2CHO) occurred directly on our planet starting from simple parent molecules of the atmosphere, liquid water and various energy sources. Miller's experiment was a milestone in this theory, but it was later recognized that the complexity of a planet cannot be reproduced in a single laboratory experiment. Some SPMs have been identified in the N2-dominated atmosphere of Titan (a massive moon of Saturn), which is believed to be reminiscent of the primitive terrestrial atmosphere. As such, the atmosphere of Titan represents a planetary scale laboratory for the comprehension of SPM formation in an environment close enough to primitive Earth and is the current frontier in the endogenous theory exploration. In the exogenous theory, SPMs came from space, the carriers being comets, asteroids and meteorites. The rationale behind this suggestion is that plenty of SPMs have been observed in interstellar clouds (ISCs), including star-forming regions, and in small bodies like comets, asteroids and meteorites. Therefore, the basic idea is that SPMs were formed in the solar nebula, preserved during the early phases of the Solar System formation in the body of comets/asteroids/meteorites and finally delivered to Earth by cometary and meteoritic falls. In this contribution, the status of our knowledge on how SPMs can be formed in the gas phase, either in the primitive terrestrial atmosphere or in the cold nebula from which the Solar System originated, will be presented. Particular attention will be given to neutral-neutral reactions.

Do plumes exist beneath Northwest Kyushu southwest Japan?

NASA Astrophysics Data System (ADS)

Mashima, H.

2014-12-01

A thermal plume model was proposed for the Hot-spot type volcanism at Northwest Kyushu, southwest Japan in the post period of opening of the Sea of Japan. The model regards the Northwest Kyushu Basalts (NWKBs) were magmas fractionated from parental magmas with MgO = 12.8 - 18.8 wt. %, indicating that partial melting occurred at temperatures from 1330 to 1500 °C and at pressures from 1.5 to 3.0 GPa (Sakuyama et al., 2009; 2014). Previous petrological and observations, however, indicate that the NWKBs separated from the source mantle at pressures shallower than those inferred from the plume model. The Mg-Fe-Ni compositions of some NWKBs suggest that they could have been in equilibrium with mantle olivines with Fo = 81 - 87, meaning that they would have been not fractionated but primitive magmas. The NWKBs are associated with primitive high magnesium andesites, indicating that partial melting continued at low pressure such as 0.5 GPa (Mashima, 2009a, b). NWKBs include not garnet lherzolite xenoliths but spinel lherzolite, showing that primitive melt separation occurred at pressure lower than 2GPa (Arai et al., 2001). These lines of evidence indicate that the separation of primitive NWKBs occurred at temperature up to 1250　°C and pressures from 0.5 to 1.5 GPa, significantly lower than those assumed by the plume model. Instead of the plume model, geology of NW Kyushu infers that the volcanism was a consequence of the tectonic evolution of NW Kyushu. The volcanism was leaks of asthenosphere thickened extensional tectonics from the Paleogene to the early Miocene. Orientations of NWKB dikes indicate their eruption was induced by the reactivation of preexisting faults under horizontal compressive stress field oriented to a NW-SE direction. This　horizontally compressive stress field would have been caused by mechanical interactions between the subducting Philippine Sea pate and the Eurasian Plate. The NW Kyushu volcanism could be explained in the context of plate tectonics without the plume hypothesis.

Os-186 and Os-187 Enrichments and High-He-3/He-4 sources in the Earth's Mantle: Evidence from Icelandic Picrites

NASA Technical Reports Server (NTRS)

Brandon, Alan D.; Graham, David W.; Waight, Tod; Gautason, Bjarni

2007-01-01

Picrites from the neovolcanic zones in Iceland display a range in Os-187/Os-188O from 0.1297 to 0.1381 ((gamma)Os = 0.0 to 6.5) and uniform Os-186/Os-188 of 0.1198375+/-32 (2 (sigma)). The value for Os-186/Os-188 is within uncertainty of the present-day value for the primitive upper mantle of 0.1198398+/-16. These Os isotope systematics are best explained by ancient recycled crust or melt enrichment in the mantle source region. If so, then the coupled enrichments displayed in Os-186/Os-188 and Os-187/Os-188 from lavas of other plume systems must result from an independent process, the most viable candidate at present remains core-mantle interaction. While some plumes with high He-3/He-4, such as Hawaii, appear to have been subjected to detectable addition of Os (and possibly He) from the outer core, others such as Iceland do not. A positive correlation between Os-187/Os-188 and He-3/He-4 from 9.6 to 19 RA in Iceland picrites is best modeled as mixtures of 500 Ma or older ancient recycled crust mixed with primitive mantle, creating a hybrid source region that subsequently mixes with the convecting MORB mantle during ascent and melting. This multistage mechanism to explain these isotope systematics is consistent with ancient recycled crust juxtaposed with more primitive, relatively He-rich mantle, in convective isolation from the upper mantle, most likely in the lowermost mantle. This is inconsistent with models that propose random mixing between heterogeneities in the convecting upper mantle as a mechanism to explain the observed isotopic variation in oceanic lavas or models that produce a high He-3/He-4 signature in melt depleted and strongly outgassed, He-poor mantle. Instead these systematics require a deep mantle source to explain the 3He/4He signature in Iceland lavas. The He-3/He-4 of lavas derived from the Iceland plume changed over time, from a maximum of 50 RA at 60 Ma, to approximately 25-27 RA at present. The changes are coupled with distinct compositional gaps between the different aged lavas when H-3/He-4 is plotted versus various geochemical parameters such as Nd-143/Nd-144 and La/Sm. These relationships can be interpreted as an increase in the proportion of ancient recycled crust in the upwelling plume over this time period.

The variable role of slab-derived fluids in the generation of a suite of primitive calc-alkaline lavas from the Southernmost Cascades, California

USGS Publications Warehouse

Borg, L.E.; Clynne, M.A.; Bullen, T.D.

1997-01-01

The compositional continuum observed in primitive calc-alkaline lavas erupted from small volcanoes across the southernmost Cascade arc is produced by the introduction of a variable proportion of slab-derived fluid into the superjacent peridotite layer of the mantle wedge. Magmas derived from fluid-rich sources are erupted primarily in the forearc and are characterized by Sr and Pb enrichment (primitive mantle-normalized Sr/P > 5.5), depletions of Ta and Nb, low incompatible-element abundances, and MORB-like Sr and Pb isotopic ratios. Magmas derived from fluid-poor sources are erupted primarily in the arc axis and behind the arc, and are characterized by weak enrichment in Sr [1.0 < (Sr/P)N < 1.3], weak depletions in Ta and Nb, higher incompatible-element abundances, and OIB-like Sr, Nd, and Pb isotopic ratios. Fluxing the mantle wedge above the subducting slab with H2O-rich fluid stabilizes amphibole and enriches the wedge peridotites in incompatible elements, particularly unradiogenic Sr and Pb. The hydrated amphibole-bearing portion of the mantle wedge is downdragged beneath the forearc, where its solidus is exceeded, yielding melts that are enriched in Sr and Pb, and depleted in Ta and Nb (reflecting both high Sr and Pb relative to Ta and Nb in the fluid, and the greater compatibility of Ta and Nb in amphibole compared to other silicate phases in the wedge). A steady decrease of the fluid-contributed geochemical signature away from the trench is produced by the progressive dehydration of the downdragged portion of the mantle wedge with depth, resulting from melt extraction and increased temperature at the slab-wedge interface. Inverse correlation between incompatible-element abundances and the size of the fluid-contributed geochemical signature is generated by melting of more depleted peridotites, rather than by significant differences in the degree of melting. High-(Sr/P)N lavas of the forearc are generated by melting of a MORB-source-like peridotite that has been fluxed with a greater proportion of slab-derived fluid, and low (Sr/P)N lavas of the arc axis are produced by melting of an OIB-source-like peridotite in the presence of a smaller proportion of slab-derived fluid. This study documents the control that a slab-derived fluid can have on incompatible element and isotopic systematics of arc magmas by 1) the addition of incompatible elements to the wedge, 2) the stabilization of hydrous phases in the wedge, and 3) the lowering of peridotite solidi.

AZD2171 in Treating Young Patients With Recurrent, Progressive, or Refractory Primary CNS Tumors

ClinicalTrials.gov

2016-03-04

Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Cerebral Anaplastic Astrocytoma; Childhood Cerebral Astrocytoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood Infratentorial Ependymoma; Childhood Oligodendroglioma; Childhood Spinal Cord Neoplasm; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Neoplasm; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway Glioma

Dynamic primitives in the control of locomotion

PubMed Central

Hogan, Neville; Sternad, Dagmar

2013-01-01

Humans achieve locomotor dexterity that far exceeds the capability of modern robots, yet this is achieved despite slower actuators, imprecise sensors, and vastly slower communication. We propose that this spectacular performance arises from encoding motor commands in terms of dynamic primitives. We propose three primitives as a foundation for a comprehensive theoretical framework that can embrace a wide range of upper- and lower-limb behaviors. Building on previous work that suggested discrete and rhythmic movements as elementary dynamic behaviors, we define submovements and oscillations: as discrete movements cannot be combined with sufficient flexibility, we argue that suitably-defined submovements are primitives. As the term “rhythmic” may be ambiguous, we define oscillations as the corresponding class of primitives. We further propose mechanical impedances as a third class of dynamic primitives, necessary for interaction with the physical environment. Combination of these three classes of primitive requires care. One approach is through a generalized equivalent network: a virtual trajectory composed of simultaneous and/or sequential submovements and/or oscillations that interacts with mechanical impedances to produce observable forces and motions. Reliable experimental identification of these dynamic primitives presents challenges: identification of mechanical impedances is exquisitely sensitive to assumptions about their dynamic structure; identification of submovements and oscillations is sensitive to their assumed form and to details of the algorithm used to extract them. Some methods to address these challenges are presented. Some implications of this theoretical framework for locomotor rehabilitation are considered. PMID:23801959

Model-Free Primitive-Based Iterative Learning Control Approach to Trajectory Tracking of MIMO Systems With Experimental Validation.

PubMed

Radac, Mircea-Bogdan; Precup, Radu-Emil; Petriu, Emil M

2015-11-01

This paper proposes a novel model-free trajectory tracking of multiple-input multiple-output (MIMO) systems by the combination of iterative learning control (ILC) and primitives. The optimal trajectory tracking solution is obtained in terms of previously learned solutions to simple tasks called primitives. The library of primitives that are stored in memory consists of pairs of reference input/controlled output signals. The reference input primitives are optimized in a model-free ILC framework without using knowledge of the controlled process. The guaranteed convergence of the learning scheme is built upon a model-free virtual reference feedback tuning design of the feedback decoupling controller. Each new complex trajectory to be tracked is decomposed into the output primitives regarded as basis functions. The optimal reference input for the control system to track the desired trajectory is next recomposed from the reference input primitives. This is advantageous because the optimal reference input is computed straightforward without the need to learn from repeated executions of the tracking task. In addition, the optimization problem specific to trajectory tracking of square MIMO systems is decomposed in a set of optimization problems assigned to each separate single-input single-output control channel that ensures a convenient model-free decoupling. The new model-free primitive-based ILC approach is capable of planning, reasoning, and learning. A case study dealing with the model-free control tuning for a nonlinear aerodynamic system is included to validate the new approach. The experimental results are given.

36 CFR 261.21 - National Forest primitive areas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false National Forest primitive areas. 261.21 Section 261.21 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE PROHIBITIONS General Prohibitions § 261.21 National Forest primitive areas. The following are...

Metabolic reprogramming: a cancer hallmark even warburg did not anticipate.

PubMed

Ward, Patrick S; Thompson, Craig B

2012-03-20

Cancer metabolism has long been equated with aerobic glycolysis, seen by early biochemists as primitive and inefficient. Despite these early beliefs, the metabolic signatures of cancer cells are not passive responses to damaged mitochondria but result from oncogene-directed metabolic reprogramming required to support anabolic growth. Recent evidence suggests that metabolites themselves can be oncogenic by altering cell signaling and blocking cellular differentiation. No longer can cancer-associated alterations in metabolism be viewed as an indirect response to cell proliferation and survival signals. We contend that altered metabolism has attained the status of a core hallmark of cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

Histochemical in situ identification of bovine embryonic blood cells reveals differences to the adult haematopoietic system and suggests a close relationship between haematopoietic stem cells and primordial germ cells.

PubMed

Kritzenberger, Michaela; Wrobel, Karl-Heinz

2004-04-01

Cryostat sections of bovine embryos of exactly known age (obtained from artificial insemination), ranging from 32 to 60 days post-insemination, were treated with a wide range of antibodies directed against cell surface antigens or lineage-specific factors in order to demonstrate different types of fetal blood cells and their precursors. An antibody specific to bovine c-kit (bk-1) stained not only presumptive haematopoietic stem cells in the dorsal aorta and the embryonic liver, but also a subpopulation of putative primordial germ cells in the gonadal anlage, the latter being further characterised by a positive labelling with the lectins STA, WFA and WGA and a histochemical reaction for alkaline phosphatase. The antibody against CD 45, commonly regarded as a pan-leukocyte marker, reacted in the bovine embryo with different types of blood cells, as well as with presumptive vasculogenetic cells and a subpopulation of putative primordial germ cells. CD 61 immunoreaction proved to be a useful tool for demonstrating megakaryocytopoiesis in the embryonic liver, in addition to the lumen of blood vessels and the mesonephros. Staining with BM-2 was restricted to a single population of medium-sized, round to oval cells, forming small groups within the parenchymal strands of the liver. Characterised furthermore by a U-shaped nucleus, this BM-2-positive cell type apparently represents a developmental stage in the granulopoietic lineage. B-lymphocytopoiesis in the bovine liver was detected with antibodies directed against WC-4 and IgM, but not until day 58 post-insemination. Using antibodies to CD 14, no positive results could be obtained in embryonic tissues, although anti-CD 14-positive macrophages were easily recognised in lymph nodes of adult bovines. The antibody against CD 68, however, identified two populations of primitive macrophages in our samples. One population was located in parenchymal strands of the embryonic liver, probably acting as nursing cells for haematopoietic foci, and the other was observed intravasally in the sinusoids of the liver, most probably representing primitive Kupffer cells.

Preconquest Peruvian neurosurgeons: a study of Inca and pre-Columbian trephination and the art of medicine in ancient Peru.

PubMed

Marino, R; Gonzales-Portillo, M

2000-10-01

Trephination and craniotomy performed by abrasion, scraping, crosscut sawing, and drilling are the oldest known surgical techniques used by primitive peoples. As a result of archaeological findings, the human skull is the most frequently studied part of the excavated body, leading to the creation of a new aspect of anthropology known as "cultural osteology." Found in ancient tombs, the human remains, mummies, skeletons, and their belongings, including war instruments, pottery, clothing, jewels, and surgical instruments, constitute the richest source of insight into the lives and pragmatic activities of ancient cultures. This study summarizes thousands of years of pre-Columbian history and medical evolution, specifically in the early and primitive practice of trephination, as precursors of neurosurgery. Comparative osteology studies have demonstrated that using primitive stone or metal instruments, the sirkaks (Inca surgeons) achieved an average survival rate of 50 to 70% of their craniectomy patients, with little incidence of infection or other complications. Despite their rudimentary knowledge of disease and pathology, a considerable knowledge of anatomy and natural medicine provided them with hemostatic agents, antiseptics, and other medical drugs, such as quinine for fever and malaria, as well as gold, silver, and other products to perform cranioplasties. Living in a world of continuous hand-to-hand combat, they also developed aggressive and defensive weapons that necessitated refinement of surgical techniques to save soldiers from battle wounds to their poorly protected crania.

Oxygen isotope geochemistry of mafic phenocrysts in primitive mafic lavas from the southernmost Cascade Range, California

USGS Publications Warehouse

Underwood, Sandra J.; Clynne, Michael A.

2017-01-01

Previously reported whole-rock δ18O values (5.6–7.8‰) for primitive quaternary mafic lavas from the southernmost Cascades (SMC) are often elevated (up to 1‰) relative to δ18O values expected for mafic magmas in equilibrium with mantle peridotite. Olivine, clinopyroxene, and plagioclase crystals were separated from 29 geochemically well-characterized mafic lavas for δ18O measurements by laser fluorination to assess modification of the mantle sources by ancient and modern subducted components. Oxygen isotope values of olivine phenocrysts in calc-alkaline lavas and contemporaneous high alumina olivine tholeiitic (HAOT) lavas generally exceed depleted mantle olivine values (~4.9–5.3‰). Modern addition of up to 6 wt% slab-derived fluid from Gorda serpentinized peridotite dehydration (~15‰) or chlorite dehydration (~10‰) within the serpentinized peridotite can provide the 18O enrichment detected in olivine phenocrysts (δ18Oolivine = 5.3–6.3‰) in calc-alkaline mafic lavas, and elevate 18O in overlying mantle lithosphere, as well. Specifically, although HAOT δ18Oolivine values (5.5–5.7‰) may reflect partial melting in heterogeneous 18O enriched mantle source domains that developed during multiple subduction events associated with terrane accretion (e.g., <1 wt% of ~15‰ materials), an additional 18O enrichment of up to 2 wt% of 10–15‰ slab-derived hydrous fluids might be accommodated. The calc-alkaline primitive magmas appear to have experienced a continuous range of open system processes, which operate in the mantle and during rapid magma ascent to eruption, and occasionally post quench. Textural relationships and geochemistry of these lava samples are consistent with blends of mafic phenocrysts and degassed melts in varying states of 18O disequilibrium. In lenses of accumulated melt within peridotite near the base of the crust, coexisting olivine and clinopyroxene δ18O values probably are not at isotopic equilibrium because fluids introduced into the system perturbed the δ18Omelt values. A “sudden” melt extraction event interrupts 18O equilibration in phenocrysts and poorly mixed melt(s). Rapid ascent of volatile oversaturated primitive mafic magma through the crust appears to be accompanied by devolatilization and crystallization of anorthite-rich plagioclase with elevated δ18Oplag values. The (Sr/P)N values for the whole rock geochemistry are consistent with a 87Sr/86Sr ~0.7027 slab-derived fluid addition into the infertile peridotite source of magmas, and melt devolatilization is recorded in the mixture of disequilibrium δ18O values for the constituent phases of lavas. Morbidity of the Gorda Plate as it undergoes intense deformation from the spreading ridge to the trench is likely a key factor to developing the carrying capacity of hydrous fluids and mineral phases in the slab subducting into the SMC mantle.

The Distributed Memory Computing Conference (5th) Held in Charleston, South Carolina on April 8-12, 1990. Volume 1. Applications

DTIC Science & Technology

1991-03-31

nodes, directional arrows show the parent and child rela- and the graphics driver runs on the CP, i.e., the tionship of processes. Although there is a...about ODB plus some number of transitory primitives, whether or not its child primitives are resident. Transitory primitives are discarded as needed...true if this Hnode’s child primitives approached. are not resident. This method of ODB decomposition has the ability to distribute a very large number of

The minimal autopoietic unit.

PubMed

Luisi, Pier Luigi

2014-12-01

It is argued that closed, cell-like compartments, may have existed in prebiotic time, showing a simplified metabolism which was bringing about a primitive form of stationary state- a kind of homeostasis. The autopoietic primitive cell can be taken as an example and there are preliminary experimental data supporting the possible existence of this primitive form of cell activity. The genetic code permits, among other things, the continuous self-reproduction of proteins; enzymic proteins permit the synthesis of nucleic acids, and in this way there is a perfect recycling between the two most important classes of biopolymers in our life. On the other hand, the genetic code is a complex machinery, which cannot be posed at the very early time of the origin of life. And the question then arises, whether some form of alternative beginning, prior to the genetic code, would have been possible: and this is the core of the question asked. Is something with the flavor of early life conceivable, prior to the genetic code? My answer is positive, although I am too well aware that the term "conceivable" does not mean that this something is easily to be performed experimentally. To illustrate my answer, I would first go back to the operational description of cellular life as given by the theory of autopoiesis. Accordingly, a living cell is an open system capable of self-maintenance, due to a process of internal self-regeneration of the components, all within a boundary which is itself product from within. This is a universal code, valid not only for a cell, but for any living macroscopic entity, as no living system exists on Earth which does not obey this principle. In this definition (or better operational description) there is no mention of DNA or genetic code. I added in that definition the term "open system"-which is not present in the primary literature (Varela, et al., 1974) to make clear that every living system is indeed an open system-without this addition, it may seem that with autopoiesis we are dealing with a perpetuum mobile, against the second principle of thermodynamics. Now consider the following figure (Fig. 1). It represents in a very schematic form a cell, as an open system, with a semipermeable membrane constituted by the chemical S, which permits the entrance of the nutrient A and the elimination of the decay product P. A is transformed inside the cell into S by a chemical reaction characterized by kgen, and S can be transformed into P by the reaction kdec. The two reactions actually may represent two entire families of reaction, in the sense that one can envisage several A and several S and several P.

Bacillus cereus strain MCN as a debriding agent

NASA Technical Reports Server (NTRS)

Dalton, H. P.; Haynes, B. W.; Stone, L. L.

1978-01-01

Biologically active means are effective for rapidly removing scar tissue caused by burns or corrosive agents. Specially selected strain of bacteria applied to injury site releases enzymes which are active against eschar. These bacteria tend to locate between eschar and unburned tissue, thus providing optimal cell surface area arrangement for enzyme dispersal. Procedure may prove especially useful in treatment of disaster casualties under relatively primitive conditions.

Mysterious Mycorrhizae? A Field Trip & Classroom Experiment to Demystify the Symbioses Formed between Plants & Fungi

ERIC Educational Resources Information Center

Johnson, Nancy C.; Chaudhary, V. Bala; Hoeksema, Jason D.; Moore, John C.; Pringle, Anne; Umbanhowar, James A.; Wilson, Gail W. T.

2009-01-01

Biology curricula cover fungi in units on bacteria, protists, and primitive plants, but fungi are more closely related to animals than to bacteria or plants. Like animals, fungi are heterotrophs and cannot create their own food; but, like plants, fungi have cell walls, and are for the most part immobile. Most species of fungi have a filamentous…

Primary extraskeletal Ewing sarcoma involving the carotid artery: a case report and review of the current literature

PubMed Central

Nikkhah, D; Nix, P; Woodhead, C

2012-01-01

Extraskeletal Ewing sarcoma (EES) is a rare soft tissue neoplasm of primitive mesenchymal cells. There is a scarcity of data on EES involving the head and neck, with studies being over years or even decades. We are the first to report a case of EES involving the carotid artery and its subsequent surgical excision and reconstruction. PMID:22613280

Use of the Primitive Unit Cell in Understanding Subtle Features of the Cubic Closest-Packed Structure

ERIC Educational Resources Information Center

Hawkins, John A.; Rittenhouse, Jeffrey L.; Soper, Linda M.; Rittenhouse, Robert C.

2008-01-01

One of the most important crystal structures adopted by metals is characterized by the "abcabc"...stacking of close-packed layers. This structure is commonly referred to in textbooks as the cubic close-packed (ccp) or face-centered cubic (fcc) structure, since the entire lattice can be generated by replication of a face-centered cubic unit cell…

Self-recognition and Ca2+-dependent carbohydrate-carbohydrate cell adhesion provide clues to the cambrian explosion.

PubMed

Fernàndez-Busquets, Xavier; Körnig, André; Bucior, Iwona; Burger, Max M; Anselmetti, Dario

2009-11-01

The Cambrian explosion of life was a relatively short period approximately 540 Ma that marked a generalized acceleration in the evolution of most animal phyla, but the trigger of this key biological event remains elusive. Sponges are the oldest extant Precambrian metazoan phylum and thus a valid model to study factors that could have unleashed the rise of multicellular animals. One such factor is the advent of self-/non-self-recognition systems, which would be evolutionarily beneficial to organisms to prevent germ-cell parasitism or the introduction of deleterious mutations resulting from fusion with genetically different individuals. However, the molecules responsible for allorecognition probably evolved gradually before the Cambrian period, and some other (external) factor remains to be identified as the missing triggering event. Sponge cells associate through calcium-dependent, multivalent carbohydrate-carbohydrate interactions of the g200 glycan found on extracellular proteoglycans. Single molecule force spectroscopy analysis of g200-g200 binding indicates that calcium affects the lifetime (+Ca/-Ca: 680 s/3 s) and bond reaction length (+Ca/-Ca: 3.47 A/2.27 A). Calculation of mean g200 dissociation times in low and high calcium within the theoretical framework of a cooperative binding model indicates the nonlinear and divergent characteristics leading to either disaggregated cells or stable multicellular assemblies, respectively. This fundamental phenomenon can explain a switch from weak to strong adhesion between primitive metazoan cells caused by the well-documented rise in ocean calcium levels at the end of Precambrian time. We propose that stronger cell adhesion allowed the integrity of genetically uniform animals composed only of "self" cells, facilitating genetic constitutions to remain within the metazoan individual and be passed down inheritance lines. The Cambrian explosion might have been triggered by the coincidence in time of primitive animals endowed with self-/non-self-recognition and of a surge in seawater calcium that increased the binding forces between their calcium-dependent cell adhesion molecules.

Proliferative status of primitive hematopoietic progenitors from patients with acute myelogenous leukemia (AML).

PubMed

Guan, Y; Hogge, D E

2000-12-01

One possible explanation for the competitive advantage that malignant cells in patients with acute myelogenous leukemia (AML) appear to have over normal hematopoietic elements is that leukemic progenitors proliferate more rapidly than their normal progenitor cell counterparts. To test this hypothesis, an overnight 3H-thymidine (3H-Tdr) suicide assay was used to analyze the proliferative status of malignant progenitors detected in both colony-forming cell (CFC) and long-term culture initiating cell (LTC-IC) assays from the peripheral blood of nine patients with newly diagnosed AML. Culture of AML cells in serum-free medium with 100 ng/ml Steel factor (SF), 20 ng/ml interleukin 3 (IL-3) and 20 ng/ml granulocyte colony-stimulating factor (G-CSF) for 16-24 h maintained the number of AML-CFC and LTC-IC at near input values (mean % input +/- s.d. for CFC and LTC-IC were 78 +/- 33 and 126 +/- 53, respectively). The addition of 20 muCi/ml high specific activity 3H-Tdr to these cultures reduced the numbers of both progenitor cell types from most of the patient samples substantially: mean % kill +/- s.d. for AML-CFC and LTC-IC were 64 +/- 27 and 82 +/- 16, respectively, indicating that a large proportion of both progenitor populations were actively cycling. FISH analysis of colonies from CFC and LTC-IC assays confirmed that most cytogenetically abnormal CFC and LTC-IC were actively cycling (mean % kill +/- s.d.: 68 +/- 26 and 85 +/- 13, respectively). Interestingly, in six patient samples where a significant number of cytogenetically normal LTC-ICs were detected, the % kill of these cells (74 +/- 20) was similar to that of the abnormal progenitors. These data contrast with the predominantly quiescent cell cycle status of CFC and LTC-IC previously observed in steady-state peripheral blood from normal individuals but also provide evidence that a significant proportion of primitive malignant progenitors from AML patients are quiescent and therefore may be resistant to standard chemotherapeutic regimens.

Stem cells--clinical application and perspectives.

PubMed

Brehm, Michael; Zeus, Tobias; Strauer, Bodo Eckehard

2002-11-01

Augmentation of myocardial performance in experimental models of therapeutic infarction and heart failure has been achieved by transplantation of exogenous cells into damaged myocardium. The quest for suitable donor cells has prompted research into the use of both embryonic stem cells and adult somatic stem cells. Recently, there has been a growing body of evidence that multipotent somatic stem cells in adult bone marrow exhibit tremendous functional plasticity and can reprogram in a new environmental tissue niche to give rise to cell lineages specific for new organ site. This phenomenon has made huge impact on myocardial biology, while multipotent adult bone marrow hematopoeitic stem cells and mesechymal stem cells can repopulate infarcted rodent myocardium and differentiate into both cardiomyocytes and new blood vessels. These data, coupled with the identification of a putative primitive cardiac stem cell population in the adult human heart, may open the way for novel therapeutic modalities for enhancing myocardial performance and treating heart failure.

Primitive magmas at five Cascade volcanic fields: Melts from hot, heterogeneous sub-arc mantle

USGS Publications Warehouse

Bacon, C.R.; Bruggman, P.E.; Christiansen, R.L.; Clynne, M.A.; Donnelly-Nolan, J. M.; Hildreth, W.

1997-01-01

Major and trace element concentrations, including REE by isotope dilution, and Sr, Nd, Pb, and O isotope ratios have been determined for 38 mafic lavas from the Mount Adams, Crater Lake, Mount Shasta, Medicine Lake, and Lassen volcanic fields, in the Cascade arc, northwestern part of the United States. Many of the samples have a high Mg# [100Mg/(Mg + FeT) > 60] and Ni content (>140 ppm) such that we consider them to be primitive. We recognize three end-member primitive magma groups in the Cascades, characterized mainly by their trace-element and alkali-metal abundances: (1) High-alumina olivine tholeiite (HAOT) has trace element abundances similar to N-MORB, except for slightly elevated LILE, and has Eu/Eu* > 1. (2) Arc basalt and basaltic andesite have notably higher LILE contents, generally have higher SiO2 contents, are more oxidized, and have higher Cr for a given Ni abundance than HAOT. These lavas show relative depletion in HFSE, have lower HREE and higher LREE than HAOT, and have smaller Eu/Eu* (0.94-1.06). (3) Alkali basalt from the Simcoe volcanic field east of Mount Adams represents the third end-member, which contributes an intraplate geochemical signature to magma compositions. Notable geochemical features among the volcanic fields are: (1) Mount Adams rocks are richest in Fe and most incompatible elements including HFSE; (2) the most incompatible-element depleted lavas occur at Medicine Lake; (3) all centers have relatively primitive lavas with high LILE/HFSE ratios but only the Mount Adams, Lassen, and Medicine Lake volcanic fields also have relatively primitive rocks with an intraplate geochemical signature; (4) there is a tendency for increasing 87Sr/86Sr, 207Pb/204Pb, and ??18O and decreasing 206Pb/204Pb and 143Nd/144Nd from north to south. The three end-member Cascade magma types reflect contributions from three mantle components: depleted sub-arc mantle modestly enriched in LILE during ancient subduction; a modern, hydrous subduction component; and OIB-source-like domains. Lavas with arc and intraplate (OIB) geochemical signatures were erupted close to HAOT, and many lavas are blends of two or more magma types. Pre-eruptive H2O contents of HAOT, coupled with phase-equilibrium studies, suggest that these magmas were relatively dry and last equilibrated in the mantle wedge at temperatures of ???1300??C and depths of ???40 km, virtually at the base of the crust. Arc basalt and basaltic andesite represent greater extents of melting than HAOT, presumably in the same general thermal regime but at somewhat lower mantle separation temperatures, of domains of sub-arc mantle that have been enriched by a hydrous subduction component derived from the young, relatively hot Juan de Fuca plate. The primitive magmas originated by partial melting in response to adiabatic upwelling within the mantle wedge. Tectonic extension in this part of the Cascade arc, one characterized by slow oblique convergence, contributes to mantle upwelling and facilitates eruption of primitive magmas.

LIF supports primitive endoderm expansion during pre-implantation development.

PubMed

Morgani, Sophie M; Brickman, Joshua M

2015-10-15

Embryonic stem cells (ESCs) are pluripotent cell lines that can be maintained indefinitely in an early developmental state. ESC culture conditions almost always require the cytokine LIF to maintain self-renewal. As ESCs are not homogeneous but contain multiple populations reminiscent of the blastocyst, identifying the target cells of LIF is necessary to understand the propagation of pluripotency. We recently found that LIF acts under self-renewing conditions to stimulate the fraction of ESCs that express extraembryonic markers, but has little impact on pluripotent gene expression. Here, we report that LIF has two distinct roles: it blocks early epiblast (Epi) differentiation, and it supports the expansion of primitive endoderm (PrE)-primed ESCs and PrE in vivo. We find that activation of JAK/STAT signalling downstream of LIF occurs initially throughout the pre-implantation embryo, but later marks the PrE. Moreover, the addition of LIF to cultured embryos increases the GATA6(+) PrE population, whereas inhibition of JAK/STAT signalling reduces both NANOG(+) epiblast and GATA6(+) PrE. The reduction of the NANOG(+) Epi might be explained by its precocious differentiation to later Epi derivatives, whereas the increase in PrE is mediated both by an increase in proliferation and inhibition of PrE apoptosis that is normally triggered in embryos with an excess of GATA6(+) cells. Thus, it appears that the relative size of the PrE is determined by the number of LIF-producing cells in the embryo. This suggests a mechanism by which the embryo adjusts the relative ratio of the primary lineages in response to experimental manipulation. © 2015. Published by The Company of Biologists Ltd.

Composition and origin of basaltic magma of the Hawaiian Islands

USGS Publications Warehouse

Powers, H.A.

1955-01-01

Silica-saturated basaltic magma is the source of the voluminous lava flows, erupted frequently and rapidly in the primitive shield-building stage of activity, that form the bulk of each Hawaiian volcano. This magma may be available in batches that differ slightly in free silica content from batch to batch both at the same and at different volcanoes; differentiation by fractionation of olivine does not occur within this primitive magma. Silica-deficient basaltic magma, enriched in alkali, is the source of commonly porphyritic lava flows erupted less frequently and in relatively negligible volume during a declining and decadent stage of activity at some Hawaiian volcanoes. Differentiation by fractionation of olivine, plagioclase and augite is evident among these lavas, but does not account for the silica deficiency or the alkali enrichment. Most of the data of Hawaiian volcanism and petrology can be explained by a hypothesis that batches of magma are melted from crystalline paridotite by a recurrent process (distortion of the equatorial bulge by forced and free nutational stresses) that accomplishes the melting only of the plagioclase and pyroxene component but not the excess olivine and more refractory components within a zone of fixed and limited depth. Eruption exhausts the supply of meltable magma under a given locality and, in the absence of more violent melting processes, leaves a stratum of crystalline refractory components. ?? 1955.

Systematic tracking of altered haematopoiesis during sporozoite-mediated malaria development reveals multiple response points.

PubMed

Vainieri, Maria L; Blagborough, Andrew M; MacLean, Adam L; Haltalli, Myriam L R; Ruivo, Nicola; Fletcher, Helen A; Stumpf, Michael P H; Sinden, Robert E; Celso, Cristina Lo

2016-06-01

Haematopoiesis is the complex developmental process that maintains the turnover of all blood cell lineages. It critically depends on the correct functioning of rare, quiescent haematopoietic stem cells (HSCs) and more numerous, HSC-derived, highly proliferative and differentiating haematopoietic progenitor cells (HPCs). Infection is known to affect HSCs, with severe and chronic inflammatory stimuli leading to stem cell pool depletion, while acute, non-lethal infections exert transient and even potentiating effects. Both whether this paradigm applies to all infections and whether the HSC response is the dominant driver of the changes observed during stressed haematopoiesis remain open questions. We use a mouse model of malaria, based on natural, sporozoite-driven Plasmodium berghei infection, as an experimental platform to gain a global view of haematopoietic perturbations during infection progression. We observe coordinated responses by the most primitive HSCs and multiple HPCs, some starting before blood parasitaemia is detected. We show that, despite highly variable inter-host responses, primitive HSCs become highly proliferative, but mathematical modelling suggests that this alone is not sufficient to significantly impact the whole haematopoietic cascade. We observe that the dramatic expansion of Sca-1(+) progenitors results from combined proliferation of direct HSC progeny and phenotypic changes in downstream populations. We observe that the simultaneous perturbation of HSC/HPC population dynamics is coupled with early signs of anaemia onset. Our data uncover a complex relationship between Plasmodium and its host's haematopoiesis and raise the question whether the variable responses observed may affect the outcome of the infection itself and its long-term consequences on the host. © 2016 The Authors.

Systematic tracking of altered haematopoiesis during sporozoite-mediated malaria development reveals multiple response points

PubMed Central

Vainieri, Maria L.; Blagborough, Andrew M.; MacLean, Adam L.; Haltalli, Myriam L. R.; Ruivo, Nicola; Fletcher, Helen A.; Stumpf, Michael P. H.; Sinden, Robert E.; Lo Celso, Cristina

2016-01-01

Haematopoiesis is the complex developmental process that maintains the turnover of all blood cell lineages. It critically depends on the correct functioning of rare, quiescent haematopoietic stem cells (HSCs) and more numerous, HSC-derived, highly proliferative and differentiating haematopoietic progenitor cells (HPCs). Infection is known to affect HSCs, with severe and chronic inflammatory stimuli leading to stem cell pool depletion, while acute, non-lethal infections exert transient and even potentiating effects. Both whether this paradigm applies to all infections and whether the HSC response is the dominant driver of the changes observed during stressed haematopoiesis remain open questions. We use a mouse model of malaria, based on natural, sporozoite-driven Plasmodium berghei infection, as an experimental platform to gain a global view of haematopoietic perturbations during infection progression. We observe coordinated responses by the most primitive HSCs and multiple HPCs, some starting before blood parasitaemia is detected. We show that, despite highly variable inter-host responses, primitive HSCs become highly proliferative, but mathematical modelling suggests that this alone is not sufficient to significantly impact the whole haematopoietic cascade. We observe that the dramatic expansion of Sca-1+ progenitors results from combined proliferation of direct HSC progeny and phenotypic changes in downstream populations. We observe that the simultaneous perturbation of HSC/HPC population dynamics is coupled with early signs of anaemia onset. Our data uncover a complex relationship between Plasmodium and its host's haematopoiesis and raise the question whether the variable responses observed may affect the outcome of the infection itself and its long-term consequences on the host. PMID:27335321

A practical approach to the clinical diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue.

PubMed

Yamaguchi, U; Hasegawa, T; Morimoto, Y; Tateishi, U; Endo, M; Nakatani, F; Kawai, A; Chuman, H; Beppu, Y; Endo, M; Kurotaki, H; Furuta, K

2005-10-01

Over 90% of Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) cases have the t(11;22) chromosomal rearrangement, which is also found in other small round cell tumours, including desmoplastic small round cell tumour (DSRCT) and clear cell sarcoma (CCS). Although this rearrangement can be analysed by fluorescence in situ hybridisation (FISH) using routinely formalin fixed, paraffin wax embedded (FFPE) tissues when fresh or frozen tissues are not available, a sensitive and convenient detection method is needed for routine clinical diagnosis. To investigate the usefulness of newly developed probes for detecting EWS rearrangement resulting from chromosomal translocations using FISH and FFPE tissue in the clinical diagnosis of ES/PNET, DSRCT, and CCS. Sixteen ES/PNETs, six DSRCTs, and six CCSs were studied. Three poorly differentiated synovial sarcomas, three alveolar rhabdomyosarcomas, and three neuroblastomas served as negative controls. Interphase FISH analysis was performed on FFPE tissue sections with a commercially available EWSR1 (22q12) dual colour, breakapart rearrangement probe. One fused signal and one split signal of orange and green, demonstrating rearrangement of the EWS gene, was detected in 14 of 16 ES/PNETs, all six DRSCTs, and five of six CCSs, but not in the negative controls. Interphase FISH using this newly developed probe is sensitive and specific for detecting the EWS gene on FFPE tissues and is of value in the routine clinical diagnosis of ES/PNET, DSRCT, and CCS.

Generalized compliant motion primitive

NASA Technical Reports Server (NTRS)

Backes, Paul G. (Inventor)

1994-01-01

This invention relates to a general primitive for controlling a telerobot with a set of input parameters. The primitive includes a trajectory generator; a teleoperation sensor; a joint limit generator; a force setpoint generator; a dither function generator, which produces telerobot motion inputs in a common coordinate frame for simultaneous combination in sensor summers. Virtual return spring motion input is provided by a restoration spring subsystem. The novel features of this invention include use of a single general motion primitive at a remote site to permit the shared and supervisory control of the robot manipulator to perform tasks via a remotely transferred input parameter set.

Primitive neuroectodermal tumors of the central nervous system.

PubMed

Becker, L E; Hinton, D

1983-06-01

Primitive neuroectodermal tumors are morphologically similar malignant tumors arising in intracranial and peripheral sites of the nervous system, showing varying degrees of cellular differentiation with a tendency to disseminate along cerebrospinal fluid pathways. They occur primarily in children and young adults. Under the designation primitive neuroectodermal tumors are included medulloblastomas and tumors that may differentiate in other directions, such as medulloepithelioma, neuroblastoma, polar spongioblastoma, pineoblastoma, ependymoblastoma, retinoblastoma, and olfactory neuroblastoma. From a practical, histologic point of view, these tumors are often indistinguishable from one another and are best thought of as primitive neuroectodermal tumors with or without differentiating features.

Prominin‐1/CD133: Lipid Raft Association, Detergent Resistance, and Immunodetection

PubMed Central

Karbanová, Jana; Lorico, Aurelio; Bornhäuser, Martin; Fargeas, Christine A.

2017-01-01

Summary The cell surface antigen prominin‐1 (alias CD133) has gained enormous interest in the past 2 decades and given rise to debates as to its utility as a biological stem and cancer stem cell marker. Important and yet often overlooked knowledge that is pertinent to its physiological function has been generated in other systems given its more general expression beyond primitive cells. This article briefly discusses the importance of particular biochemical features of CD133 with relation to its association with membrane microdomains (lipid rafts) and proper immunodetection. It also draws attention toward the adequate use of detergents and caveats that may apply to the interpretation of the results generated. Stem Cells Translational Medicine 2018;7:155–160 PMID:29271118

Histogenesis of the epithelial component of rat thymus: an ultrastructural and immunohistological analysis.

PubMed

Vicente, A; Varas, A; Sacedón, R; Zapata, A G

1996-04-01

Despite the assumed importance of thymic cell microenvironments for governing T-cell maturation, little is known about the ontogeny of their cell components. A few studies have analyzed previously the ontogenetical development of rat thymic epithelium (Bogojevic et al. 1990. Period. Biol., 92:126; Kampinga and Aspinall 1990 Harwood Acad. Pub., London, pp. 149-186; Micic et al., 1991 Dev. Comp. Immunol., 15:443-450) and recently we have reported the development of both interdigitating/dendritic cells and macrophages (Vicente et al., 1994 Immunology, 82:75-81, 1995 Immunology, 85:99-105). In the present work we analyze in situ ultrastructural, immunohistochemical, and histoenzymatically the appearance and development of the thymic epithelial cell component in both embryonic and neonatal Wistar rats with special emphasis on the origin of the different epithelial cell types, the occurrence or absence of a common precursor for these, and the expression of MHC molecules. The thymic primordium of 13-day-old embryos is formed by a homogeneous population of primitive epithelial cells differentiating gradually into various epithelial cell subtypes of both the cortex and the medulla. In the cortex, subcapsular and stroma-supporting epithelial cells appear at days 14-15 as two structurally different cell entities. At the same time, stroma-supporting, keratinized, and vacuolated epithelial cells occur in the thymic medulla. These last two cell types differentiate subsequently into Hassall's bodies and hypertrophied cells. Lympho-epithelial cell complexes are identified in the deep cortex around birth, when the cortical parenchyma houses a transitional erythropoiesis. mAbs (His-39, RMC-20) which recognize medullary epithelial cells in the adult thymus stain positively cells of the thymic primordium as early as day 16 of embryonic life. Cortical epithelial cell markers (His-37, RMC-17) appear, however, slightly later and the subcapsulary region is not established until postnatal life. MHC class I and class II molecules can be identified on epithelial cells in the thymus of 15-day-old embryonic rats although they reach the highest expression around birth. Our results confirm the heterogeneity of the thymic epithelial component, the persistence of primitive, non-differentiated epithelial cells morphologically similar to those occurring in the early thymic primordium in adult thymus, and the mutual relevance of epithelial cells and thymocytes for an adequate development of rat thymus gland.

Cancer stem cells and cell size: A causal link?

PubMed

Li, Qiuhui; Rycaj, Kiera; Chen, Xin; Tang, Dean G

2015-12-01

The majority of normal animal cells are 10-20 μm in diameter. Many signaling mechanisms, notably PI3K/Akt/mTOR, Myc, and Hippo pathways, tightly control and coordinate cell growth, cell size, cell division, and cell number during homeostasis. These regulatory mechanisms are frequently deregulated during tumorigenesis resulting in wide variations in cell sizes and increased proliferation in cancer cells. Here, we first review the evidence that primitive stem cells in adult tissues are quiescent and generally smaller than their differentiated progeny, suggesting a correlation between small cell sizes with the stemness. Conversely, increased cell size positively correlates with differentiation phenotypes. We then discuss cancer stem cells (CSCs) and present some evidence that correlates cell sizes with CSC activity. Overall, a causal link between CSCs and cell size is relatively weak and remains to be rigorously assessed. In the future, optimizing methods for isolating cells based on size should help elucidate the connection between cancer cell size and CSC characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Density of Primitive Pythagorean Triples

ERIC Educational Resources Information Center

Killen, Duncan A.

2004-01-01

Based on the properties of a Primitive Pythagorean Triple (PPT), a computer program was written to generate, print, and count all PPTs greater than or equal to I[subscript x], where I[subscript x] is an arbitrarily chosen integer. The Density of Primitive Pythagorean Triples may be defined as the ratio of the number of PPTs whose hypotenuse is…

A Discussion on the Substitution Method for Trigonometric Rational Functions

ERIC Educational Resources Information Center

Ponce-Campuzano, Juan Carlos; Rivera-Figueroa, Antonio

2011-01-01

It is common to see, in the books on calculus, primitives of functions (some authors use the word "antiderivative" instead of primitive). However, the majority of authors pay scant attention to the domains over which the primitives are valid, which could lead to errors in the evaluation of definite integrals. In the teaching of calculus, in…

Scientific Terminology and Minimum Terms in Speech Communication: Some Philosophical Ramblings.

ERIC Educational Resources Information Center

Krivonos, Paul D.; Sussman, Lyle.

Philosophers of science have emphasized the need for primitive terms, or "givens," in the construction of theory for any discipline. While there are inherent dangers regarding the use of primitive terms, they can have great value in serving as the basis for minimum terms, which are primitive terms unique to a discipline. (Borrowed terms are those…

A manual for PARTI runtime primitives

NASA Technical Reports Server (NTRS)

Berryman, Harry; Saltz, Joel

1990-01-01

Primitives are presented that are designed to help users efficiently program irregular problems (e.g., unstructured mesh sweeps, sparse matrix codes, adaptive mesh partial differential equations solvers) on distributed memory machines. These primitives are also designed for use in compilers for distributed memory multiprocessors. Communications patterns are captured at runtime, and the appropriate send and receive messages are automatically generated.

Low oxygen atmosphere facilitates proliferation and maintains undifferentiated state of umbilical cord mesenchymal stem cells in an hypoxia inducible factor-dependent manner.

PubMed

Drela, Katarzyna; Sarnowska, Anna; Siedlecka, Patrycja; Szablowska-Gadomska, Ilona; Wielgos, Miroslaw; Jurga, Marcin; Lukomska, Barbara; Domanska-Janik, Krystyna

2014-07-01

As we approach the era of mesenchymal stem cell (MSC) application in the medical clinic, the standarization of their culture conditions are of the particular importance. We re-evaluated the influences of oxygens concentration on proliferation, stemness and differentiation of human umbilical cord Wharton Jelly-derived MSCs (WJ-MSCs). Primary cultures growing in 21% oxygen were either transferred into 5% O2 or continued to grow under standard 21% oxygen conditions. Cell expansion was estimated by WST1/enzyme-linked immunosorbent assay or cell counting. After 2 or 4 weeks of culture, cell phenotypes were evaluated using microscopic, immunocytochemical, fluorescence-activated cell-sorting and molecular methods. Genes and proteins typical of mesenchymal cells, committed neural cells or more primitive stem/progenitors (Oct4A, Nanog, Rex1, Sox2) and hypoxia inducible factor (HIF)-1α-3α were evaluated. Lowering O2 concentration from 21% to the physiologically relevant 5% level substantially affected cell characteristics, with induction of stemness-related-transcription-factor and stimulation of cell proliferative capacity, with increased colony-forming unit fibroblasts (CFU-F) centers exerting OCT4A, NANOG and HIF-1α and HIF-2α immunoreactivity. Moreover, the spontaneous and time-dependent ability of WJ-MSCs to differentiate into neural lineage under 21% O2 culture was blocked in the reduced oxygen condition. Importantly, treatment with trichostatin A (TSA, a histone deacetylase inhibitor) suppressed HIF-1α and HIF-2α expression, in addition to blockading the cellular effects of reduced oxygen concentration. A physiologically relevant microenvironment of 5% O2 rejuvenates WJ-MSC culture toward less-differentiated, more primitive and faster-growing phenotypes with involvement of HIF-1α and HIF-2α-mediated and TSA-sensitive chromatin modification mechanisms. These observations add to the understanding of MSC responses to defined culture conditions, which is the most critical issue for adult stem cells translational applications. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Is plagioclase removal responsible for the negative Eu anomaly in the source regions of mare basalts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shearer, C.K.; Papike, J.J.

1989-12-01

The nearly ubiquitous presence of a negative Eu anomaly in the mare basalts has been suggested to indicate prior separation and flotation of plagioclase from the basalt source region during its crystallization from a lunar magma ocean (LMO). Are there any mare basalts derived from a mantle source which did not experience prior plagioclase separation Crystal chemical rationale for REE substitution in pyroxene suggests that the combination of REE size and charge, M2 site characteristics of pyroxene, fO{sub 2}, magma chemistry, and temperature may account for the negative Eu anomaly in the source region of some types of primitive, lowmore » TiO{sub 2} mare basalts. This origin for the negative Eu anomaly does not preclude the possibility of the LMO as many mare basalts still require prior plagioclase crystallization and separation and/or hybridization involving a KREEP component.« less

Biochemical evolution III: Polymerization on organophilic silica-rich surfaces, crystal–chemical modeling, formation of first cells, and geological clues

PubMed Central

Smith, Joseph V.; Arnold, Frederick P.; Parsons, Ian; Lee, Martin R.

1999-01-01

Catalysis at organophilic silica-rich surfaces of zeolites and feldspars might generate replicating biopolymers from simple chemicals supplied by meteorites, volcanic gases, and other geological sources. Crystal–chemical modeling yielded packings for amino acids neatly encapsulated in 10-ring channels of the molecular sieve silicalite-ZSM-5-(mutinaite). Calculation of binding and activation energies for catalytic assembly into polymers is progressing for a chemical composition with one catalytic Al–OH site per 25 neutral Si tetrahedral sites. Internal channel intersections and external terminations provide special stereochemical features suitable for complex organic species. Polymer migration along nano/micrometer channels of ancient weathered feldspars, plus exploitation of phosphorus and various transition metals in entrapped apatite and other microminerals, might have generated complexes of replicating catalytic biomolecules, leading to primitive cellular organisms. The first cell wall might have been an internal mineral surface, from which the cell developed a protective biological cap emerging into a nutrient-rich “soup.” Ultimately, the biological cap might have expanded into a complete cell wall, allowing mobility and colonization of energy-rich challenging environments. Electron microscopy of honeycomb channels inside weathered feldspars of the Shap granite (northwest England) has revealed modern bacteria, perhaps indicative of Archean ones. All known early rocks were metamorphosed too highly during geologic time to permit simple survival of large-pore zeolites, honeycombed feldspar, and encapsulated species. Possible microscopic clues to the proposed mineral adsorbents/catalysts are discussed for planning of systematic study of black cherts from weakly metamorphosed Archaean sediments. PMID:10097060

Emergence of Functional Hierarchy in a Multiple Timescale Neural Network Model: A Humanoid Robot Experiment

PubMed Central

Yamashita, Yuichi; Tani, Jun

2008-01-01

It is generally thought that skilled behavior in human beings results from a functional hierarchy of the motor control system, within which reusable motor primitives are flexibly integrated into various sensori-motor sequence patterns. The underlying neural mechanisms governing the way in which continuous sensori-motor flows are segmented into primitives and the way in which series of primitives are integrated into various behavior sequences have, however, not yet been clarified. In earlier studies, this functional hierarchy has been realized through the use of explicit hierarchical structure, with local modules representing motor primitives in the lower level and a higher module representing sequences of primitives switched via additional mechanisms such as gate-selecting. When sequences contain similarities and overlap, however, a conflict arises in such earlier models between generalization and segmentation, induced by this separated modular structure. To address this issue, we propose a different type of neural network model. The current model neither makes use of separate local modules to represent primitives nor introduces explicit hierarchical structure. Rather than forcing architectural hierarchy onto the system, functional hierarchy emerges through a form of self-organization that is based on two distinct types of neurons, each with different time properties (“multiple timescales”). Through the introduction of multiple timescales, continuous sequences of behavior are segmented into reusable primitives, and the primitives, in turn, are flexibly integrated into novel sequences. In experiments, the proposed network model, coordinating the physical body of a humanoid robot through high-dimensional sensori-motor control, also successfully situated itself within a physical environment. Our results suggest that it is not only the spatial connections between neurons but also the timescales of neural activity that act as important mechanisms leading to functional hierarchy in neural systems. PMID:18989398

Comet Dust: The Diversity of "Primitive" Particles and Implications

NASA Technical Reports Server (NTRS)

Wooden, Diane H.; Ishii, Hope A.; Bradley, John P.; Zolensky, Michael E.

2016-01-01

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples ( IDP's(Interplanetary Dust Particles) and AMM's (Antarctic Micrometeorites)) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contents of the silicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The uniformity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properties of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

Comet Dust: The Diversity of Primitive Particles and Implications

NASA Technical Reports Server (NTRS)

John Bradley; Zolensky, Michael E.

2016-01-01

Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive particles has expanded significantly through microscale investigations of cosmic dust samples (IDPs and AMMs) and of comet dust samples (Stardust and Rosetta's COSIMA), as well as through remote sensing (spectroscopy and imaging) via Spitzer and via spacecraft encounters with 103P/Hartley 2 and 67P/Churyumov-Gerasimenko. Microscale investigations show that comet dust and cosmic dust are particles of unequilibrated materials, including aggregates of materials unequilibrated at submicron scales. We call unequilibrated materials "primitive" and we deduce they were incorporated into ice-­-rich (H2O-, CO2-, and CO-ice) parent bodies that remained cold, i.e., into comets, because of the lack of aqueous or thermal alteration since particle aggregation; yet some Stardust olivines suggest mild thermal metamorphism. Primitive particles exhibit a diverse range of: structure and typology; size and size distribution of constituents; concentration and form of carbonaceous and organic matter; D-, N-, and O- isotopic enhancements over solar; Mg-, Fe-contentsof thesilicate minerals; the compositions and concentrations of sulfides, and of less abundant mineral species such as chondrules, CAIs and carbonates. The unifomity within a group of samples points to: aerodynamic sorting of particles and/or particle constituents; the inclusion of a limited range of oxygen fugacities; the inclusion or exclusion of chondrules; a selection of organics. The properites of primitive particles imply there were disk processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disk present at the time and in the region where the comets formed.

The Architectural Organization of Human Stem Cell Cycle Regulatory Machinery

PubMed Central

Stein, Gary S.; Stein, Janet L.; Wijnen, Andre van J; Lian, Jane B.; Montecino, Martin; Medina, Ricardo; Kapinas, Kristie; Ghule, Prachi; Grandy, Rodrigo; Zaidi, Sayyed K.; Becker, Klaus A.

2013-01-01

Two striking features of human embryonic stem cells that support biological activity are an abbreviated cell cycle and reduced complexity to nuclear organization. The potential implications for rapid proliferation of human embryonic stem cells within the context of sustaining pluripotency, suppressing phenotypic gene expression and linkage to simplicity in the architectural compartmentalization of regulatory machinery in nuclear microenvironments is explored. Characterization of the molecular and architectural commitment steps that license human embryonic stem cells to initiate histone gene expression is providing understanding of the principal regulatory mechanisms that control the G1/S phase transition in primitive pluripotent cells. From both fundamental regulatory and clinical perspectives, further understanding of the pluripotent cell cycle in relation to compartmentalization of regulatory machinery in nuclear microenvironments is relevant to applications of stem cells for regenerative medicine and new dimensions to therapy where traditional drug discovery strategies have been minimally effective. PMID:22394165

Yoga Therapy in Treating Patients With Malignant Brain Tumors

ClinicalTrials.gov

2017-07-27

Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Anaplastic Meningioma; Adult Anaplastic Oligodendroglioma; Adult Brain Stem Glioma; Adult Choroid Plexus Tumor; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade II Meningioma; Adult Medulloblastoma; Adult Meningeal Hemangiopericytoma; Adult Mixed Glioma; Adult Oligodendroglioma; Adult Papillary Meningioma; Adult Pineal Gland Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Supratentorial Primitive Neuroectodermal Tumor (PNET); Recurrent Adult Brain Tumor

Testing a Hypothesis for the Evolution of Sex

NASA Astrophysics Data System (ADS)

Örçal, Bora; Tüzel, Erkan; Sevim, Volkan; Jan, Naeem; Erzan, Ayşe.

An asexual set of primitive bacteria is simulated with a bit-string Penna model with a Fermi function for survival. A recent hypothesis by Jan, Stauffer, and Moseley on the evolution of sex from asexual cells as a strategy for trying to escape the effects of deleterious mutations is checked. This strategy is found to provide a successful scenario for the evolution of a stable macroscopic sexual population.

Circuit design tool. User's manual, revision 2

NASA Technical Reports Server (NTRS)

Miyake, Keith M.; Smith, Donald E.

1992-01-01

The CAM chip design was produced in a UNIX software environment using a design tool that supports definition of digital electronic modules, composition of these modules into higher level circuits, and event-driven simulation of these circuits. Our design tool provides an interface whose goals include straightforward but flexible primitive module definition and circuit composition, efficient simulation, and a debugging environment that facilitates design verification and alteration. The tool provides a set of primitive modules which can be composed into higher level circuits. Each module is a C-language subroutine that uses a set of interface protocols understood by the design tool. Primitives can be altered simply by recoding their C-code image; in addition new primitives can be added allowing higher level circuits to be described in C-code rather than as a composition of primitive modules--this feature can greatly enhance the speed of simulation.

Retention of primitive reflexes and delayed motor development in very low birth weight infants.

PubMed

Marquis, P J; Ruiz, N A; Lundy, M S; Dillard, R G

1984-06-01

Primitive reflexes and motor development were evaluated in 127 very low birth weight (VLBW) infants (birth weight less than 1501 grams) at four months corrected age. The asymmetrical tonic neck reflex, tonic labyrinth reflex, and Moro reflex were assessed for each child. The ability of each child to reach (obtain a red ring) and roll were observed. The child's performance on the gross motor scale of the Denver Development Screening Test was recorded. Thirty-seven term infants were administered identical evaluations at four months of age. The VLBW infants retained stronger primitive reflexes and exhibited a significantly higher incidence of motor delays than term infants. Significant correlations existed between the strength of the primitive reflexes and early motor development for VLBW infants. This study confirms a high incidence of motor delays among VLBW infants and demonstrates a clear association between retained primitive reflexes and delayed motor development in VLBW infants.

RIPE integrity primitives, part 2 (RACE Integrity Primitives Evaluation)

NASA Astrophysics Data System (ADS)

Denboer, B.; Boly, J. P.; Bosselaers, A.; Brandt, J.; Chaum, D.; Damgaard, I.; Dichtl, M.; Fumy, W.; Vanderham, M.; Jansen, C. J. A.

1993-04-01

A manual intended for those seeking to secure information systems by applying modern cryptography is presented. It represents the successful attainment of goals by RIPE (RACE (Research and development of Advanced Communications technology in Europe) Integrity Primitives Evaluation). The recommended portfolio of integrity primitives, which is the main product of the project, forms the heart of the manual. By integrity, is meant the kinds of security that can be achieved through cryptography, apart from keeping messages secret. Thus included are ways to ensure that stored or communicated data is not illicitly modified, that parties exchanging messages are actually present, and that 'signed' electronic messages can be recognized as authentic by anyone. Of particular concern to the project were the high speed requirements of broadband communication. The project also aimed for completeness in its recommendations. As a result, the portfolio contains primitives, that is building blocks, that can meet most of today's perceived needs for integrity.

RIPE integrity primitives, part 1 (RACE Integrity Primitives Evaluation)

NASA Astrophysics Data System (ADS)

Denboer, B.; Boly, J. P.; Bosselaers, A.; Brandt, J.; Chaum, D.; Damgaard, I.; Dichtl, M.; Fumy, W.; Vanderham, M.; Jansen, C. J. A.

1993-04-01

A manual intended for those seeking to secure information systems by applying modern cryptography is presented. It represents the successful attainment of goals by RIPE (RACE (Research and development of Advanced Communication technology in Europe) Integrity Primitives Evaluation). The recommended portfolio of integrity primitives, which is the main product of the project, forms the heart of the manual. By integrity, is meant the kinds of security that can be achieved through cryptography, apart from keeping messages secret. Thus included are ways to ensure that stored or communicated data is not illicitly modified, that parties exchanging messages are actually present, and that 'signed' electronic messages can be recognized as authentic by anyone. Of particular concern to the project were the high speed requirements of broadband communication. The project also aimed for completeness in its recommendations. As a result, the portfolio contains primitives, that is building blocks, that can meet most of today's perceived needs for integrity.

Alkane inducible proteins in Geobacillus thermoleovorans B23

PubMed Central

2009-01-01

Background Initial step of β-oxidation is catalyzed by acyl-CoA dehydrogenase in prokaryotes and mitochondria, while acyl-CoA oxidase primarily functions in the peroxisomes of eukaryotes. Oxidase reaction accompanies emission of toxic by-product reactive oxygen molecules including superoxide anion, and superoxide dismutase and catalase activities are essential to detoxify them in the peroxisomes. Although there is an argument about whether primitive life was born and evolved under high temperature conditions, thermophilic archaea apparently share living systems with both bacteria and eukaryotes. We hypothesized that alkane degradation pathways in thermophilic microorganisms could be premature and useful to understand their evolution. Results An extremely thermophilic and alkane degrading Geobacillus thermoleovorans B23 was previously isolated from a deep subsurface oil reservoir in Japan. In the present study, we identified novel membrane proteins (P16, P21) and superoxide dismutase (P24) whose production levels were significantly increased upon alkane degradation. Unlike other bacteria acyl-CoA oxidase and catalase activities were also increased in strain B23 by addition of alkane. Conclusion We first suggested that peroxisomal β-oxidation system exists in bacteria. This eukaryotic-type alkane degradation pathway in thermophilic bacterial cells might be a vestige of primitive living cell systems that had evolved into eukaryotes. PMID:19320977

Crystallization and preliminary X-ray analysis of ginkbilobin-2 from Ginkgo biloba seeds: a novel antifungal protein with homology to the extracellular domain of plant cysteine-rich receptor-like kinases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyakawa, Takuya; Sawano, Yoriko; Miyazono, Ken-ichi

Purification and crystallization of ginkbilobin-2 and its selenomethionine derivative allowed the collection of complete data to 2.38 Å resolution and multiwavelength anomalous diffraction data sets, respectively. The antifungal protein ginkbilobin-2 (Gnk2) from Ginkgo biloba seeds does not show homology to other pathogenesis-related proteins, but does show homology to the extracellular domain of plant cysteine-rich receptor-like kinases. Native Gnk2 purified from ginkgo nuts and the selenomethionine derivative of recombinant Gnk2 (SeMet-rGnk2) were crystallized by the sitting-drop vapour-diffusion method using different precipitants. X-ray diffraction data were collected from Gnk2 at 2.38 Å resolution and from SeMet-rGnk2 at 2.79 Å resolution using amore » synchrotron-radiation source. The crystals of both proteins belonged to the primitive cubic space group P2{sub 1}3, with unit-cell parameters a = b = c = 143.2 Å.« less

Formation of amino acids by cobalt-60 irradiation of hydrogen cyanide solutions

NASA Technical Reports Server (NTRS)

Sweeney, M. A.; Toste, A. P.; Ponnamperuma, C.

1976-01-01

Experiments were conducted to study the pathway for the prebiotic origin of amino acids from hydrogen cyanide (HCN) under the action of ionizing radiation considered as an effective source of energy on the primitive earth. The irradiations were performed in a cobalt-60 source with a dose rate of 200,000 rad/hr. Seven naturally occurring amino acids are identified among the products formed by the hydrolysis of gamma-irradiated solutions of HCN: glycine, alanine, valine, serine, threonine, aspartic acid, and glutamic acid. The identity of these amino acids is established by gas chromatography and mass spectrometry. Control experiments provided evidence that the amino acids are not the result of contamination.

SL(2, C) group action on cohomological field theories

NASA Astrophysics Data System (ADS)

Basalaev, Alexey

2018-01-01

We introduce the S} (2,C) group action on a partition function of a cohomological field theory via a certain Givental's action. Restricted to the small phase space we describe the action via the explicit formulae on a CohFT genus g potential. We prove that applied to the total ancestor potential of a simple-elliptic singularity the action introduced coincides with the transformation of Milanov-Ruan changing the primitive form (cf. Milanov and Ruan in Gromov-Witten theory of elliptic orbifold P1 and quasi-modular forms, arXiv:1106.2321 , 2011).

Historical Development of Origins Research

PubMed Central

Lazcano, Antonio

2010-01-01

Following the publication of the Origin of Species in 1859, many naturalists adopted the idea that living organisms were the historical outcome of gradual transformation of lifeless matter. These views soon merged with the developments of biochemistry and cell biology and led to proposals in which the origin of protoplasm was equated with the origin of life. The heterotrophic origin of life proposed by Oparin and Haldane in the 1920s was part of this tradition, which Oparin enriched by transforming the discussion of the emergence of the first cells into a workable multidisciplinary research program. On the other hand, the scientific trend toward understanding biological phenomena at the molecular level led authors like Troland, Muller, and others to propose that single molecules or viruses represented primordial living systems. The contrast between these opposing views on the origin of life represents not only contrasting views of the nature of life itself, but also major ideological discussions that reached a surprising intensity in the years following Stanley Miller’s seminal result which showed the ease with which organic compounds of biochemical significance could be synthesized under putative primitive conditions. In fact, during the years following the Miller experiment, attempts to understand the origin of life were strongly influenced by research on DNA replication and protein biosynthesis, and, in socio-political terms, by the atmosphere created by Cold War tensions. The catalytic versatility of RNA molecules clearly merits a critical reappraisal of Muller’s viewpoint. However, the discovery of ribozymes does not imply that autocatalytic nucleic acid molecules ready to be used as primordial genes were floating in the primitive oceans, or that the RNA world emerged completely assembled from simple precursors present in the prebiotic soup. The evidence supporting the presence of a wide range of organic molecules on the primitive Earth, including membrane-forming compounds, suggests that the evolution of membrane-bounded molecular systems preceded cellular life on our planet, and that life is the evolutionary outcome of a process, not of a single, fortuitous event. PMID:20534710

RO4929097, Temozolomide, and Radiation Therapy in Treating Patients With Newly Diagnosed Malignant Glioma

ClinicalTrials.gov

2015-09-28

Acoustic Schwannoma; Adult Anaplastic (Malignant) Meningioma; Adult Anaplastic Astrocytoma; Adult Anaplastic Ependymoma; Adult Brain Stem Glioma; Adult Choroid Plexus Neoplasm; Adult Craniopharyngioma; Adult Diffuse Astrocytoma; Adult Ependymoblastoma; Adult Ependymoma; Adult Giant Cell Glioblastoma; Adult Glioblastoma; Adult Gliosarcoma; Adult Grade I Meningioma; Adult Grade II Meningioma; Adult Medulloblastoma; Adult Mixed Glioma; Adult Myxopapillary Ependymoma; Adult Oligodendroglioma; Adult Papillary Meningioma; Adult Pilocytic Astrocytoma; Adult Pineal Gland Astrocytoma; Adult Pineoblastoma; Adult Pineocytoma; Adult Primary Melanocytic Lesion of Meninges; Adult Subependymal Giant Cell Astrocytoma; Adult Subependymoma; Adult Supratentorial Primitive Neuroectodermal Tumor; Malignant Adult Intracranial Hemangiopericytoma

Ispinesib in Treating Young Patients With Relapsed or Refractory Solid Tumors or Lymphoma

ClinicalTrials.gov

2013-01-15

Childhood Burkitt Lymphoma; Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Spinal Cord Neoplasm; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Brain Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Unspecified Childhood Solid Tumor, Protocol Specific

Aerospace Medicine and Biology. A Continuing Bibliography with Indexes

DTIC Science & Technology

1987-12-01

GLYCERALDEHYDE AS A SOURCE OF SIMULATION ABOUT THE ORIGIN OF LIFE ENERGY AND MONOMERS FOR PREBIOTIC CONDENSATION URSULA NIESERT (Freiburg, Universitaet, Freiburg...primitive prebiotic replication system. The adsorption of Poly-C, Poly-U, Poly-A, Poly-G, and 5’-AMP, 5’-GMP, 5’-CMP and 5’-UMP onto gypsum was studied. It...Cambridge University Press. 1986. 378 p. For individual titles see A87-49035 to A87-49049. Topics discussed include prebiotic systems and evolutionary

Quantum discord as a resource for quantum cryptography.

PubMed

Pirandola, Stefano

2014-11-07

Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper.

Quantum discord as a resource for quantum cryptography

PubMed Central

Pirandola, Stefano

2014-01-01

Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper. PMID:25378231

Establishment of mouse expanded potential stem cells

PubMed Central

Gao, Xuefei; Antunes, Liliana; Yu, Yong; Zhu, Zhexin; Wang, Juexuan; Kolodziejczyk, Aleksandra A.; Campos, Lia S.; Wang, Cui; Yang, Fengtang; Zhong, Zhen; Fu, Beiyuan; Eckersley-Maslin, Melanie A.; Woods, Michael; Tanaka, Yosuke; Chen, Xi; Wilkinson, Adam C.; Bussell, James; White, Jacqui; Ramirez-Solis, Ramiro; Reik, Wolf; Göttgens, Berthold; Teichmann, Sarah A.; Tam, Patrick P. L.; Nakauchi, Hiromitsu; Zou, Xiangang; Lu, Liming; Liu, Pentao

2018-01-01

Mouse embryonic stem cells derived from the epiblast1 contribute to the somatic lineages and the germline but are excluded from the extra-embryonic tissues that are derived from the trophectoderm and the primitive endoderm2 upon reintroduction to the blastocyst. Here we report that cultures of expanded potential stem cells can be established from individual eight-cell blastomeres, and by direct conversion of mouse embryonic stem cells and induced pluripotent stem cells. Remarkably, a single expanded potential stem cell can contribute both to the embryo proper and to the trophectoderm lineages in a chimaera assay. Bona fide trophoblast stem cell lines and extra-embryonic endoderm stem cells can be directly derived from expanded potential stem cells in vitro. Molecular analyses of the epigenome and single-cell transcriptome reveal enrichment for blastomere-specific signature and a dynamic DNA methylome in expanded potential stem cells. The generation of mouse expanded potential stem cells highlights the feasibility of establishing expanded potential stem cells for other mammalian species. PMID:29019987

Using Abstraction in Explicity Parallel Programs.

DTIC Science & Technology

1991-07-01

However, we only rely on sequential consistency of memory operations. includ- ing reads. writes and any synchronization primitives provided by the...explicit synchronization primitives . This demonstrates the practical power of sequentially consistent memory, as opposed to weaker models of memory that...a small set of synchronization primitives , all pro- cedures have non-waiting specifications. This is in contrast to richer process-oriented

Semantically-Sensitive Macroprocessing

DTIC Science & Technology

1989-12-15

constr uct for protecting critical regions. Given the synchronization primitives P and V, we might implement the following transformation, where...By this we mean that the semantic model for the base language provides a primitive set of concepts, represented by data types and operations...the gener- ation of a (dynamic-) semantically equivalent program fragment ultimately expressible in terms of built-in primitives . Note that static

A manual for PARTI runtime primitives, revision 1

NASA Technical Reports Server (NTRS)

Das, Raja; Saltz, Joel; Berryman, Harry

1991-01-01

Primitives are presented that are designed to help users efficiently program irregular problems (e.g., unstructured mesh sweeps, sparse matrix codes, adaptive mesh partial differential equations solvers) on distributed memory machines. These primitives are also designed for use in compilers for distributed memory multiprocessors. Communications patterns are captured at runtime, and the appropriate send and receive messages are automatically generated.

Hematopoietic Stem Cells in Neonates: Any Differences between Very Preterm and Term Neonates?

PubMed Central

Wisgrill, Lukas; Schüller, Simone; Bammer, Markus; Berger, Angelika; Pollak, Arnold; Radke, Teja Falk; Kögler, Gesine; Spittler, Andreas; Helmer, Hanns; Husslein, Peter; Gortner, Ludwig

2014-01-01

Background In the last decades, human full-term cord blood was extensively investigated as a potential source of hematopoietic stem and progenitor cells (HSPCs). Despite the growing interest of regenerative therapies in preterm neonates, only little is known about the biological function of HSPCs from early preterm neonates under different perinatal conditions. Therefore, we investigated the concentration, the clonogenic capacity and the influence of obstetric/perinatal complications and maternal history on HSPC subsets in preterm and term cord blood. Methods CD34+ HSPC subsets in UCB of 30 preterm and 30 term infants were evaluated by flow cytometry. Clonogenic assays suitable for detection of the proliferative potential of HSPCs were conducted. Furthermore, we analyzed the clonogenic potential of isolated HSPCs according to the stem cell marker CD133 and aldehyde dehydrogenase (ALDH) activity. Results Preterm cord blood contained a significantly higher concentration of circulating CD34+ HSPCs, especially primitive progenitors, than term cord blood. The clonogenic capacity of HSPCs was enhanced in preterm cord blood. Using univariate analysis, the number and clonogenic potential of circulating UCB HSPCs was influenced by gestational age, birth weight and maternal age. Multivariate analysis showed that main factors that significantly influenced the HSPC count were maternal age, gestational age and white blood cell count. Further, only gestational age significantly influenced the clonogenic potential of UCB HSPCs. Finally, isolated CD34+/CD133+, CD34+/CD133– and ALDHhigh HSPC obtained from preterm cord blood showed a significantly higher clonogenic potential compared to term cord blood. Conclusion We demonstrate that preterm cord blood exhibits a higher HSPC concentration and increased clonogenic capacity compared to term neonates. These data may imply an emerging use of HSPCs in autologous stem cell therapy in preterm neonates. PMID:25181353

Fast concurrent array-based stacks, queues and deques using fetch-and-increment-bounded, fetch-and-decrement-bounded and store-on-twin synchronization primitives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Dong; Gara, Alana; Heidelberger, Philip

Implementation primitives for concurrent array-based stacks, queues, double-ended queues (deques) and wrapped deques are provided. In one aspect, each element of the stack, queue, deque or wrapped deque data structure has its own ticket lock, allowing multiple threads to concurrently use multiple elements of the data structure and thus achieving high performance. In another aspect, new synchronization primitives FetchAndIncrementBounded (Counter, Bound) and FetchAndDecrementBounded (Counter, Bound) are implemented. These primitives can be implemented in hardware and thus promise a very fast throughput for queues, stacks and double-ended queues.

Probabilistic structural analysis of a truss typical for space station

NASA Technical Reports Server (NTRS)

Pai, Shantaram S.

1990-01-01

A three-bay, space, cantilever truss is probabilistically evaluated using the computer code NESSUS (Numerical Evaluation of Stochastic Structures Under Stress) to identify and quantify the uncertainties and respective sensitivities associated with corresponding uncertainties in the primitive variables (structural, material, and loads parameters) that defines the truss. The distribution of each of these primitive variables is described in terms of one of several available distributions such as the Weibull, exponential, normal, log-normal, etc. The cumulative distribution function (CDF's) for the response functions considered and sensitivities associated with the primitive variables for given response are investigated. These sensitivities help in determining the dominating primitive variables for that response.

Efficient Agent-Based Models for Non-Genomic Evolution

NASA Technical Reports Server (NTRS)

Gupta, Nachi; Agogino, Adrian; Tumer, Kagan

2006-01-01

Modeling dynamical systems composed of aggregations of primitive proteins is critical to the field of astrobiological science involving early evolutionary structures and the origins of life. Unfortunately traditional non-multi-agent methods either require oversimplified models or are slow to converge to adequate solutions. This paper shows how to address these deficiencies by modeling the protein aggregations through a utility based multi-agent system. In this method each agent controls the properties of a set of proteins assigned to that agent. Some of these properties determine the dynamics of the system, such as the ability for some proteins to join or split other proteins, while additional properties determine the aggregation s fitness as a viable primitive cell. We show that over a wide range of starting conditions, there are mechanisins that allow protein aggregations to achieve high values of overall fitness. In addition through the use of agent-specific utilities that remain aligned with the overall global utility, we are able to reach these conclusions with 50 times fewer learning steps.

Significance of solvated electrons (e(aq)-) as promoters of life on earth.

PubMed

Getoff, Nikola

2014-01-01

Based on the present state of knowledge a new hypothesis concerning the origin of life on Earth is presented, and emphasizes the particular significance of solvated electrons (e(aq)(-)). Solvated electrons are produced in seawater, mainly by (40)K radiation and in atmospheric moisture by VUV light, electrical discharges and cosmic ray. Solvated electrons are involved in primary chemical processes and in biological processes. The conversion of aqueous CO2 and CO into simple organic substances, the generation of ammonia from N2 and water, the formation of amines, amino acids and simple proteins under the action of e(aq)(-) has been experimentally proven. Furthermore, it is supposed that the generation of the primitive cell and equilibria of primitive enzymes are also realized due to the strong reducing property of e(aq)(-). The presented hypothesis is mainly founded on recently obtained experimental results. The involvement of e(aq)(-) in such mechanisms, as well as their action as an initiator of life is also briefly discussed.

A method of plane geometry primitive presentation

NASA Astrophysics Data System (ADS)

Jiao, Anbo; Luo, Haibo; Chang, Zheng; Hui, Bin

2014-11-01

Point feature and line feature are basic elements in object feature sets, and they play an important role in object matching and recognition. On one hand, point feature is sensitive to noise; on the other hand, there are usually a huge number of point features in an image, which makes it complex for matching. Line feature includes straight line segment and curve. One difficulty in straight line segment matching is the uncertainty of endpoint location, the other is straight line segment fracture problem or short straight line segments joined to form long straight line segment. While for the curve, in addition to the above problems, there is another difficulty in how to quantitatively describe the shape difference between curves. Due to the problems of point feature and line feature, the robustness and accuracy of target description will be affected; in this case, a method of plane geometry primitive presentation is proposed to describe the significant structure of an object. Firstly, two types of primitives are constructed, they are intersecting line primitive and blob primitive. Secondly, a line segment detector (LSD) is applied to detect line segment, and then intersecting line primitive is extracted. Finally, robustness and accuracy of the plane geometry primitive presentation method is studied. This method has a good ability to obtain structural information of the object, even if there is rotation or scale change of the object in the image. Experimental results verify the robustness and accuracy of this method.

Constraints on the origin of the Moon's atmosphere from observations during a lunar eclipse.

PubMed

Mendillo, M; Baumgardner, J

1995-10-05

The properties of the Moon's rarefied atmosphere, which can be traced through observations of sodium and potassium, provide important insights into the formation and maintenance of atmospheres on other primitive Solar System bodies. The lunar atmosphere is believed to be composed of atoms from the surface rocks and soil, which might have been sputtered by micrometeorites, by ions in the solar wind, or by photons. It might also form by the evaporation of atoms from the hot, illuminated surface. Here we report the detection of sodium emission from the Moon's atmosphere during a total lunar eclipse (which occurs when the Moon is full). The sodium atmosphere is considerably more extended at full Moon than expected--it extends to at least nine lunar radii--and its brightness distribution is incompatible with sources involving either solar-wind or micrometeorite sputtering. This leaves photon sputtering or thermal desorption as the preferred explanations for the lunar atmosphere, and suggests that sunlight might also be responsible for the transient atmospheres of other primitive bodies (such as Mercury).

Oxygen isotope and trace element compositions of platiniferous dunite pipes of the Bushveld Complex, South Africa - Signals from a recycled mantle component?

NASA Astrophysics Data System (ADS)

Günther, T.; Haase, K. M.; Junge, M.; Oberthür, T.; Woelki, D.; Krumm, S.

2018-06-01

Platiniferous dunite pipes occur in the lower mafic/ultramafic portion of the Rustenburg Layered Suite of the Bushveld large igneous province (LIP). Olivine compositions in these pipes range from forsterite (Fo) 80 to 35 mol% and suggest crystallization from variably evolved magmas at high temperatures ( 1200 °C). The most primitive olivines are from a stock unit and have the highest contents of Ni (>0.15 wt%) and lowest contents of Mn (<0.3 wt%). Fractional crystallization and partial melting of pyroxenite host rock play a significant role in the formation of the fayalitic olivines with its high Mn contents (>0.3 wt%). High δ18O values of olivine (5.7-7.0‰) and pyroxene (6.7-7.4‰) are akin to those of the Lower and Critical Zone of the Bushveld intrusion suggesting a common origin. The constant high O isotope ratios with variable Fo contents in the olivines are unlike trends observed in olivine phenocrysts in magmas forming by assimilation-fractional crystallization. We suggest that the high δ18O in the most primitive dunites reflect that of the primary melt of the Bushveld pipes, indicating either a bulk assimilation of crust prior to pipe formation or a contribution from recycled oceanic crust in the sub-continental lithospheric mantle (SCLM). The latter scenario is supported by the high Ni/Mn ratios in primitive pipe olivine that might be inherited from melting of a pyroxene-rich mantle source.

Geochemical signals of progressive continental rupture in the Main Ethiopian Rift

NASA Astrophysics Data System (ADS)

Furman, T.; Bryce, J.; Yirgu, G.; Ayalew, D.; Cooper, L.

2003-04-01

Mafic volcanics of the Main Ethiopian Rift record the development of magmatic rift segments during continental extension. The Ethiopian Rift is one arm of a triple junction that formed above a Paleogene mantle plume, concurrent with eruption of flood basalts ca. 30 Ma across northern Ethiopian and Yemen. The geochemistry of Ethiopian Rift lavas thus provides insight into processes associated with the shift from mechanical (lithospheric) to magmatic (asthenospheric) segmentation in the transitional phase of continental rifting. Quaternary basalts from five volcanic centers representing three magmatic segments display along-axis geochemical variations that likely reflect the degree of rifting and magma supply, which increase abruptly with proximity to the highly-extended Afar region. To first order, the geochemical data indicate a decreasing degree of shallow-level fractionation and greater involvement of depleted or plume-like mantle source materials in basalts sampled closer to the Afar. These spatially controlled geochemical signatures observed in contemporaneous basalts are similar to temporal variations documented in southern Ethiopia, where Quaternary lavas indicate a greater degree of crustal extension than those erupted at the onset of plume activity. Primitive Ethiopian Rift basalts have geochemical signatures (e.g., Ce/Pb, La/Nb, Ba/Nb, Ba/Rb, U/Th) that overlap ocean island basalt compositions, suggesting involvement of sub-lithospheric source materials. The estimated depth of melting (65-75 km) is shallower than values obtained for young primitive mafic lavas from the Western Rift and southern Kenya as well as Oligocene Ethiopian flood basalts from the onset of plume-driven activity. Basalts from the Turkana region (N. Kenya) and Erta 'Ale (Danakil depression) reflect melting at shallower levels, corresponding to the greater degree of crustal extension in these provinces. Preliminary Sr and Nd isotopic data trend towards primitive earth values, consistent with values observed previously in central Ethiopia that are associated with moderately high 3He/4He values (<19 RA; Marty et al. 1996) and interpreted as reflecting involvement of a mantle plume. Taken together, these data support a model in which upwelling plume material sampled in central Ethiopia incorporates depleted mantle during ascent beneath the more highly extended portions of the African Rift.

Alveolar macrophages develop from fetal monocytes that differentiate into long-lived cells in the first week of life via GM-CSF

PubMed Central

De Kleer, Ismé; Henri, Sandrine; Post, Sijranke; Vanhoutte, Leen; De Prijck, Sofie; Deswarte, Kim; Malissen, Bernard; Hammad, Hamida; Lambrecht, Bart N.

2013-01-01

Tissue-resident macrophages can develop from circulating adult monocytes or from primitive yolk sac–derived macrophages. The precise ontogeny of alveolar macrophages (AMFs) is unknown. By performing BrdU labeling and parabiosis experiments in adult mice, we found that circulating monocytes contributed minimally to the steady-state AMF pool. Mature AMFs were undetectable before birth and only fully colonized the alveolar space by 3 d after birth. Before birth, F4/80hiCD11blo primitive macrophages and Ly6ChiCD11bhi fetal monocytes sequentially colonized the developing lung around E12.5 and E16.5, respectively. The first signs of AMF differentiation appeared around the saccular stage of lung development (E18.5). Adoptive transfer identified fetal monocytes, and not primitive macrophages, as the main precursors of AMFs. Fetal monocytes transferred to the lung of neonatal mice acquired an AMF phenotype via defined developmental stages over the course of one week, and persisted for at least three months. Early AMF commitment from fetal monocytes was absent in GM-CSF–deficient mice, whereas short-term perinatal intrapulmonary GM-CSF therapy rescued AMF development for weeks, although the resulting AMFs displayed an immature phenotype. This demonstrates that tissue-resident macrophages can also develop from fetal monocytes that adopt a stable phenotype shortly after birth in response to instructive cytokines, and then self-maintain throughout life. PMID:24043763

Comparative Anatomy of Maintenance Tasks (CAMT): A Feasibility Study

DTIC Science & Technology

1992-03-01

systems. Methods for task primitive definition were developed, then taken into the field for testing . Task primitives were defined to cover three remove...engine maintenance) and to test whether task primitives developed for one weapon system could have applicability to other weapon systems (Phase 2...requirements, levying MPT constraints and predicting MPT requirements are only ritualistic exercises until the operational test and evaluation of a

Mechanism of Muong Nong-type tektite formation and speculation on the source of Australasian tektites

NASA Technical Reports Server (NTRS)

Schnetzler, C. C.

1992-01-01

The source crater of the youngest and largest of the tektite strewnfields, the Australasian strewnfield, has not been located. A number of lines of evidence indicate that the Muong Nong-type tektites, primarily found in Indochina, are more primitive than the much more abundant and widespread splash-form tektites, and are proximal to the source. In this study the spatial distribution of Muong Nong-type tektite sites and chemical character have been used to indicate the approximate location of the source. The variation of Muong Nong-type tektite chemical composition appears to be caused by mixing of two silicate rock end-members and a small amount of limestone, and not by vapor fractionation. The variation in composition is not random, and does not support in situ melting or multiple impact theories. The distribution of both Muong Nong and splash-form tektite sites suggest the source is in a limited area near the southern part of the Thailand-Laos border.

E-Waste Informal Recycling: An Emerging Source of Lead Exposure in South America

PubMed Central

Pascale, Antonio; Sosa, Adriana; Bares, Cristina; Battocletti, Alejandra; Moll, María José; Pose, Darío; Laborde, Amalia; González, Hugo; Feola, Gabriella

2016-01-01

BACKGROUND Primitive electronic waste (e-waste) recycling creates exposures to several hazardous substances including lead. In Uruguay, primitive recycling procedures are a significant source of lead exposure. OBJECTIVES The aim of this study was to examine lead exposure in blood lead levels (BLLs) in low-income children exposed to lead through burning cables. METHODS A sample of children and adolescents exposed to lead through burning cable activities were assessed at the Department of Toxicology in Montevideo, Uruguay, between 2010 and 2014. Soil lead levels of residences were taken shortly after their assessment. FINDINGS The final sample included 69 children and adolescents (mean age 7.89 years). More than 66% of participants had an additional source of lead exposure—manual gathering of metals—and <5% were exposed to lead through landfills or paint. Average BLLs at first consultation were 9.19 ug/dL and lower at the second measurement (5.86 μg/dL). Data from soil lead levels ranged from 650 to 19,000 mg of lead/kg of soil. The interventions conducted after the assessment included family education in the clinic and at home, indoor and outdoor remediation. We found a decrease in BLLs of 6.96 μg/dL. Older children had lower BLLs (r = −0.24; P =0.05). Statistical analyses also showed that children living in areas with higher soil lead levels had significantly higher BLLs (r = 0.50; P < 0.01). Additionally, we found greater BLLs from burning cable activities when children had been exposed to lead-based paint (r = 0.23; P < 0.1). CONCLUSION Among children exposed to e-waste recycling, the most common additional source of lead exposure was the manual gathering of metals. The average BLL among children and adolescents in this study is higher than the BLLs currently suggested in medical intervention. Future research should focus on exploring effective interventions to reduce lead exposure among this vulnerable group. PMID:27325077

Re-Os isotope and platinum group elements of a FOcal ZOne mantle source, Louisville Seamounts Chain, Pacific ocean

NASA Astrophysics Data System (ADS)

Tejada, Maria Luisa G.; Hanyu, Takeshi; Ishikawa, Akira; Senda, Ryoko; Suzuki, Katsuhiko; Fitton, Godfrey; Williams, Rebecca

2015-02-01

The Louisville Seamount Chain (LSC) is, besides the Hawaiian-Emperor Chain, one of the longest-lived hotspot traces. We report here the first Re-Os isotope and platinum group element (PGE) data for Canopus, Rigil, and Burton Guyots along the chain, which were drilled during IODP Expedition 330. The LSC basalts possess (187Os/188Os)i = 0.1245-0.1314 that are remarkably homogeneous and do not vary with age. A Re-Os isochron age of 64.9 ± 3.2 Ma was obtained for Burton seamount (the youngest of the three seamounts drilled), consistent with 40Ar-39Ar data. Isochron-derived initial 187Os/188Os ratio of 0.1272 ± 0.0008, together with data for olivines (0.1271-0.1275), are within the estimated primitive mantle values. This (187Os/188Os)i range is similar to those of Rarotonga (0.124-0.139) and Samoan shield (0.1276-0.1313) basalts and lower than those of Cook-Austral (0.136-0.155) and Hawaiian shield (0.1283-0.1578) basalts, suggesting little or no recycled component in the LSC mantle source. The PGE data of LSC basalts are distinct from those of oceanic lower crust. Variation in PGE patterns can be largely explained by different low degrees of melting under sulfide-saturated conditions of the same relatively fertile mantle source, consistent with their primitive mantle-like Os and primordial Ne isotope signatures. The PGE patterns and the low 187Os/188Os composition of LSC basalts contrast with those of Ontong Java Plateau (OJP) tholeiites. We conclude that the Re-Os isotope and PGE composition of LSC basalts reflect a relatively pure deep-sourced common mantle sampled by some ocean island basalts but is not discernible in the composition of OJP tholeiites.

Noble gas data from Goldfield and Tonopah epithermal Au-Ag deposits, ancestral Cascades Arc, USA: Evidence for a primitive mantle volatile source

USGS Publications Warehouse

Manning, Andrew H.; Hofstra, Albert H.

2017-01-01

The He, Ne, and Ar isotopic composition of fluid inclusions in ore and gangue minerals were analyzed to determine the source of volatiles in the high-grade Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada, USA. Ar and Ne are mainly atmospheric, whereas He has only a minor atmospheric component. Corrected 3He/4He ratios (with atmospheric He removed) range widely from 0.05 to 35.8 times the air 3He/4He ratio (RA), with a median of 1.43 RA. Forty-one percent of measured 3He/4He ratios are ≥4 RA, corresponding to ≥50% mantle He assuming a mantle ratio of 8 RA. These results suggest that mafic magmas were part of the magmatic-hydrothermal system underlying Goldfield and Tonopah, and that associated mantle-sourced volatiles may have played a role in ore formation. The three highest corrected 3He/4He ratios of 17.0, 23.7, and 35.8 RAindicate a primitive mantle He source and are the highest yet reported for any epithermal-porphyry system and for the Cascades arc region. Compiled 3He/4He measurements from epithermal-porphyry systems in subduction-related magmatic arcs around the world (n = 209) display a statistically significant correlation between 3He/4He and Au-Ag grade. The correlation suggests that conditions which promote higher fluid inclusion 3He/4He ratios (abundance of mantle volatiles and focused upward volatile transport) have some relation to conditions that promote higher Au-Ag grades (focused flow of metal-bearing fluids and efficient chemical traps). Results of this and previous investigations of He isotopes in epithermal-porphyry systems are consistent with the hypothesis posed in recent studies that mafic magmas serve an important function in the formation of these deposits.

Endogenous Synthesis of Prebiotic Organic Molecules

NASA Technical Reports Server (NTRS)

Miller, Stanley L.

1996-01-01

The necessary condition for the synthesis of organic compounds on the primitive earth is the presence of reducing conditions. This means an atmosphere of CH4, CO, or CO2 + H2. The atmospheric nitrogen can be N2 with a trace of NH3, but NH4(+) is needed in the ocean at least for amino acid synthesis. Many attempts have been made to use CO2 + H2O atmospheres for prebiotic synthesis, but these give at best extremely low yields of organic compounds, except in the presence of H2. Even strong reducing agents such as FeS + H2S or the mineral assemblages of the submarine vents fail to give significant yields of organic compounds with CO2. There appears to be a high kinetic barrier to the non-biological reduction of CO2 at low temperatures using geological reducing agents. The most abundant source of energy for prebiotic synthesis is ultraviolet light followed by electric discharges, with electric discharges being more efficient, although it is not clear which was the important energy source. Photochemical process would also make significant contributions. In an atmosphere Of CO2, N2, and H2O with no H2, the production rates of HCN and H2CO would be very low, 0.001 or less than that of a relatively reducing atmosphere. The concentration of organic compounds under these non-reducing conditions would be so low that there is doubt whether the concentration mechanism would be adequate for further steps toward the origin of life. A number of workers have calculated the influx of comets and meteorites on the primitive earth as a source of organic compounds. We conclude that while some organic material was added to the earth from comets and meteorites the amount available from these sources at a given time was at best only a few percent of that from earth bases syntheses under reducing conditions.

Physics of the primitive solar nebula and of giant gaseous protoplanets

NASA Technical Reports Server (NTRS)

Cameron, A. G. W.

1978-01-01

It has been proposed that the supernova responsible for injecting Al-26 into the early solar system was in fact responsible for triggering the collapse of an interstellar cloud in order to produce a system of stars, one of which would be the solar system. Details concerning the mechanism involved in such a process are discussed. Attention is given to the evolution of the primitive solar nebula, the instabilities in the primitive solar nebula, and the giant gaseous protoplanets. The principal conclusion to be drawn from the material presented is that the primitive solar nebula was a rather chaotic place, highly turbulent, with the multiple formation of giant gaseous protoplanets.

Microbioreactor Arrays for Full Factorial Screening of Exogenous and Paracrine Factors in Human Embryonic Stem Cell Differentiation

PubMed Central

Titmarsh, Drew M.; Hudson, James E.; Hidalgo, Alejandro; Elefanty, Andrew G.; Stanley, Edouard G.; Wolvetang, Ernst J.; Cooper-White, Justin J.

2012-01-01

Timed exposure of pluripotent stem cell cultures to exogenous molecules is widely used to drive differentiation towards desired cell lineages. However, screening differentiation conditions in conventional static cultures can become impractical in large parameter spaces, and is intrinsically limited by poor spatiotemporal control of the microenvironment that also makes it impossible to determine whether exogenous factors act directly or through paracrine-dependent mechanisms. We detail here the development of a continuous flow microbioreactor array platform that combines full-factorial multiplexing of input factors with progressive accumulation of paracrine factors through serially-connected culture chambers, and further, the use of this system to explore the combinatorial parameter space of both exogenous and paracrine factors involved in human embryonic stem cell (hESC) differentiation to a MIXL1-GFP+ primitive streak-like population. We show that well known inducers of primitive streak (BMP, Activin and Wnt signals) do not simply act directly on hESC to induce MIXL1 expression, but that this requires accumulation of surplus, endogenous factors; and, that conditioned medium or FGF-2 supplementation is able to offset this. Our approach further reveals the presence of a paracrine, negative feedback loop to the MIXL1-GFP+ population, which can be overcome with GSK-3β inhibitors (BIO or CHIR99021), implicating secreted Wnt inhibitory signals such as DKKs and sFRPs as candidate effectors. Importantly, modulating paracrine effects identified in microbioreactor arrays by supplementing FGF-2 and CHIR in conventional static culture vessels resulted in improved differentiation outcomes. We therefore demonstrate that this microbioreactor array platform uniquely enables the identification and decoding of complex soluble factor signalling hierarchies, and that this not only challenges prevailing strategies for extrinsic control of hESC differentiation, but also is translatable to conventional culture systems. PMID:23300662

O-Fucosylation of Thrombospondin Type 1 Repeats Restricts Epithelial to Mesenchymal Transition (EMT) and Maintains Epiblast Pluripotency During Mouse Gastrulation

PubMed Central

Du, Jianguang; Takeuchi, Hideyuki; Leonhard-Melief, Christina; Shroyer, Kenneth R.; Dlugosz, Malgosia; Haltiwanger, Robert S.; Holdener, Bernadette C.

2010-01-01

Thrombospondin type 1 repeat (TSR) superfamily members regulate diverse biological activities ranging from cell motility to inhibition of angiogenesis. In this study, we verified that mouse protein O-fucosyltransferase-2 (POFUT2) specifically adds O-fucose to TSRs. Using two Pofut2 gene trap lines, we demonstrated that O-fucosylation of TSRs was essential for restricting epithelial to mesenchymal transition in the primitive streak, correct patterning of mesoderm, and localization of the definitive endoderm. Although Pofut2 mutant embryos established anterior/posterior polarity, they underwent extensive mesoderm differentiation at the expense of maintaining epiblast pluripotency. Moreover, mesoderm differentiation was biased towards the vascular endothelial cell lineage. Localization of Foxa2 and Cer1 expressing cells within the interior of Pofut2 mutant embryos suggested that POFUT2 activity was also required for the displacement of the primitive endoderm by definitive endoderm. Notably, Nodal, BMP4, Fgf8, and Wnt3 expression were markedly elevated and expanded in Pofut2 mutants, providing evidence that O-fucose modification of TSRs was essential for modulation of growth factor signaling during gastrulation. The ability of Pofut2 mutant embryos to form teratomas comprised of tissues from all three germ layer origins suggested that defects in Pofut2 mutant embryos resulted from abnormalities in the extracellular environment. This prediction is consistent with the observation that POFUT2 targets are constitutive components of the extracellular matrix (ECM) or associate with the ECM. For this reason, the Pofut2 mutants represent a valuable tool for studying the role of O-fucosylation in ECM synthesis and remodeling, and will be a valuable model to study how post-translational modification of ECM components regulates the formation of tissue boundaries, cell movements, and signaling. PMID:20637190

Cooperation between both Wnt/β-catenin and PTEN/PI3K/Akt signaling promotes primitive hematopoietic stem cell self-renewal and expansion

PubMed Central

Perry, John M.; He, Xi C.; Sugimura, Ryohichi; Grindley, Justin C.; Haug, Jeffrey S.; Ding, Sheng; Li, Linheng

2011-01-01

Although self-renewal is the central property of stem cells, the underlying mechanism remains inadequately defined. Using a hematopoietic stem and progenitor cell (HSPC)-specific conditional induction line, we generated a compound genetic model bearing both Pten deletion and β-catenin activation. These double mutant mice exhibit a novel phenotype, including expansion of phenotypic long-term hematopoietic stem cells (LT-HSCs) without extensive differentiation. Unexpectedly, constitutive activation of β-catenin alone results in apoptosis of HSCs. However, together, the Wnt/β-catenin and PTEN/PI3k/Akt pathways interact to drive phenotypic LT-HSC expansion by inducing proliferation while simultaneously inhibiting apoptosis and blocking differentiation, demonstrating the necessity of complementary cooperation between the two pathways in promoting self-renewal. Mechanistically, β-catenin activation reduces multiple differentiation-inducing transcription factors, blocking differentiation partially through up-regulation of Inhibitor of differentiation 2 (Id2). In double mutants, loss of Pten enhances the HSC anti-apoptotic factor Mcl-1. All of these contribute in a complementary way to HSC self-renewal and expansion. While permanent, genetic alteration of both pathways in double mutant mice leads to expansion of phenotypic HSCs, these HSCs cannot function due to blocked differentiation. We developed a pharmacological approach to expand normal, functional HSCs in culture using factors that reversibly activate both Wnt/β-catenin and PI3K/Akt signaling simultaneously. We show for the first time that activation of either single pathway is insufficient to expand primitive HSCs, but in combination, both pathways drive self-renewal and expansion of HSCs with long-term functional capacity. PMID:21890648

Effects of Spaceflight on Cells of Bone Marrow Origin

PubMed Central

Özçivici, Engin

2013-01-01

Once only a subject for science fiction novels, plans for establishing habitation on space stations, the Moon, and distant planets now appear among the short-term goals of space agencies. This article reviews studies that present biomedical issues that appear to challenge humankind for long-term spaceflights. With particularly focus on cells of bone marrow origin, studies involving changes in bone, immune, and red blood cell populations and their functions due to extended weightlessness were reviewed. Furthermore, effects of mechanical disuse on primitive stem cells that reside in the bone marrow were also included in this review. Novel biomedical solutions using space biotechnology will be required in order to achieve the goal of space exploration without compromising the functions of bone marrow, as spaceflight appears to disrupt homeostasis for all given cell types. Conflict of interest:None declared. PMID:24385745

Orbitotomy for retrobulbar malignant fibrous histiocytoma in a dog.

PubMed

Lassaline, Mary E; Gelatt, Kirk N; Brooks, Dennis E; Ellison, Gary W

2005-01-01

A retrobulbar malignant fibrous histiocytoma was diagnosed in a 12-year-old castrated male Keeshond dog. The mass was excised with a lateral orbitotomy and zygomatic arch resection. Vision was preserved in the affected eye, and no recurrence was noted up to 10 months postoperatively. Malignant fibrous histiocytoma originates from primitive mesenchymal stem cells. The malignant fibrous histiocytoma seen in our patient was most consistent with the storiform-pleomorphic variant, given the storiform arrangement of spindle cells, the presence of histiocytoid cells, and a mixed inflammatory infiltrate, without giant cells. The metastatic potential of malignant fibrous histiocytoma in general, and the storiform variant in particular, is unknown. Seventeen months later the dog was presented to the referring veterinarian with anorexia, diarrhea, weight loss and bilateral purulent nasal exudates. The dog was euthanized without necropsy.

CD22 and Siglec-G in B cell function and tolerance

PubMed Central

Poe, Jonathan C.; Tedder, Thomas F.

2012-01-01

The immune system has evolved into two main arms, the primitive innate arm that is the first line of defense but relatively short-lived and broad acting, and the advanced adaptive arm that generates immunologic “memory” allowing rapid, specific recall responses. T cell-independent type-2 (TI-2) antigens (Ags) invoke innate immune responses. However, due to its “at the ready” nature, how the innate arm of the immune system maintains tolerance to potentially abundant host TI-2 Ags remains elusive. Therefore, it is important to define the mechanisms that establish innate immune tolerance. This review highlights recent insights into B cell tolerance to theoretical self TI-2 Ags, and examines how the B cell-restricted Siglecs, CD22 and Siglec-G, might contribute to this process. PMID:22677186

Possible complex organic compounds on Mars.

PubMed

Kobayashi, K; Sato, T; Kajishima, S; Kaneko, T; Ishikawa, Y; Saito, T

1997-01-01

It is suggested that primitive Mars had somehow similar environments as primitive Earth. If life was born on the primitive earth using organic compounds which were produced from the early Earth environment, the same types of organic compounds were also formed on primitive Mars. Such organic compounds might have been preserved on Mars still now. We are studying possible organic formation on primitive and present Mars. A gaseous mixture of CO2, CO, N2 and H2O with various mixing ratios were irradiated with high energy protons (major components of cosmic rays). Hydrogen cyanide and formaldehyde were detected among volatile products, and yellow-brown-colored water-soluble non-volatile substances were produced, which gave amino acids after acid-hydrolysis. Major part of "amino acid precursors" were not simple molecules like aminonitriles, but complex compounds which eluted earlier than free amino acids in cation-exchange HPLC. These organic compounds should be major targets in the future Mars mission. Strategy for the detection of the complex organics on Mars will be discussed.

Using Parallel Processing for Problem Solving.

DTIC Science & Technology

1979-12-01

are the basic parallel proces- sing primitive . Different goals of the system can be pursued in parallel by placing them in separate activities...Language primitives are provided for manipulating running activities. Viewpoints are a generalization of context FOM -(over "*’ DD I FON 1473 ’EDITION OF I...arc the basic parallel processing primitive . Different goals of the system can be pursued in parallel by placing them in separate activities. Language

Security Primitives for Reconfigurable Hardware-Based Systems

DTIC Science & Technology

2010-05-01

work, we propose security primitives using ideas centered around the notion of “moats and drawbridges .” The primitives encompass four design properties...Santa Bar- bara, CA 93106; email: sherwood@cs.ucsb.edu; R. Kastner, Department of Computer Science and Engineering , University of California, San...fingerprint reader), the other to control the ethernet IP core—and an AES encryption engine used by both of the processor cores. These cores are all implemented

Spectrum Analysis of Inertial and Subinertial Motions Based on Analyzed Winds and Wind-Driven Currents from a Primitive Equation General Ocean Circulation Model.

DTIC Science & Technology

1982-12-01

1Muter.Te Motions Based on Ana lyzed Winds and wind-driven December 1982 Currents from. a Primitive Squat ion General a.OW -love"*..* Oean Circulation...mew se"$ (comeS.... do oISN..u am ae~ 00do OWaor NUN Fourier and Rotary Spc , Analysis Modeled Inertial and Subinrtial Motion 4 Primitive Equation

A Generalized-Compliant-Motion Primitive

NASA Technical Reports Server (NTRS)

Backes, Paul G.

1993-01-01

Computer program bridges gap between planning and execution of compliant robotic motions developed and installed in control system of telerobot. Called "generalized-compliant-motion primitive," one of several task-execution-primitive computer programs, which receives commands from higher-level task-planning programs and executes commands by generating required trajectories and applying appropriate control laws. Program comprises four parts corresponding to nominal motion, compliant motion, ending motion, and monitoring. Written in C language.

Intrapartum synthetic oxytocin reduce the expression of primitive reflexes associated with breastfeeding.

PubMed

Marín Gabriel, Miguel A; Olza Fernández, Ibone; Malalana Martínez, Ana M; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

2015-05-01

Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. A cohort prospective study was conducted at a tertiary hospital. Mother-infant dyads who received intrapartum oxytocin (n=53) were compared with mother-infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent.

MACOP modular architecture with control primitives

PubMed Central

Waegeman, Tim; Hermans, Michiel; Schrauwen, Benjamin

2013-01-01

Walking, catching a ball and reaching are all tasks in which humans and animals exhibit advanced motor skills. Findings in biological research concerning motor control suggest a modular control hierarchy which combines movement/motor primitives into complex and natural movements. Engineers inspire their research on these findings in the quest for adaptive and skillful control for robots. In this work we propose a modular architecture with control primitives (MACOP) which uses a set of controllers, where each controller becomes specialized in a subregion of its joint and task-space. Instead of having a single controller being used in this subregion [such as MOSAIC (modular selection and identification for control) on which MACOP is inspired], MACOP relates more to the idea of continuously mixing a limited set of primitive controllers. By enforcing a set of desired properties on the mixing mechanism, a mixture of primitives emerges unsupervised which successfully solves the control task. We evaluate MACOP on a numerical model of a robot arm by training it to generate desired trajectories. We investigate how the tracking performance is affected by the number of controllers in MACOP and examine how the individual controllers and their generated control primitives contribute to solving the task. Furthermore, we show how MACOP compensates for the dynamic effects caused by a fixed control rate and the inertia of the robot. PMID:23888140

A real-time robot arm collision detection system

NASA Technical Reports Server (NTRS)

Shaffer, Clifford A.; Herb, Gregory M.

1990-01-01

A data structure and update algorithm are presented for a prototype real time collision detection safety system for a multi-robot environment. The data structure is a variant of the octree, which serves as a spatial index. An octree recursively decomposes 3-D space into eight equal cubic octants until each octant meets some decomposition criteria. The octree stores cylspheres (cylinders with spheres on each end) and rectangular solids as primitives (other primitives can easily be added as required). These primitives make up the two seven degrees-of-freedom robot arms and environment modeled by the system. Octree nodes containing more than a predetermined number N of primitives are decomposed. This rule keeps the octree small, as the entire environment for the application can be modeled using a few dozen primitives. As robot arms move, the octree is updated to reflect their changed positions. During most update cycles, any given primitive does not change which octree nodes it is in. Thus, modification to the octree is rarely required. Incidents in which one robot arm comes too close to another arm or an object are reported. Cycle time for interpreting current joint angles, updating the octree, and detecting/reporting imminent collisions averages 30 milliseconds on an Intel 80386 processor running at 20 MHz.

Compositions of Mars Rocks: SNC Meteorites, Differentiates, and Soils

NASA Technical Reports Server (NTRS)

Rutherford, M. J.; Minitti, M.; Weitz, C. M.

1999-01-01

The 13 samples from Mars identified in the terrestrial meteorite collections vary from dunite to pyroxenite to microgabbro or basalt. All of these rocks appear to have formed from primitive melts with similar major element compositional characteristics; i.e., FeO-rich and Al2O3-Poor melts relative to terrestrial basalt compositions. Although all of the SNC rocks can be derived by melting of the same Al-depleted mantle, contamination of SNC's by a Rb-enriched mantle or crustal source is required to explain the different REE characteristics of SNC rocks. Thus, there are indications of an old crustal rocktype on Mars, and this rock does not appear to have been sampled. This paper focuses primarily on the composition of the SNC basalts, however, and on the compositions of rocks which could be derived from SNC basaltic melt by magmatic processes. In particular, we consider the possible compositions which could be achieved through accumulation of early-formed crystals in the SNC primitive magma. Through a set of experiments we have determined (1) melt (magma) compositions which could be produced by melt evolution as crystals are removed from batches of this magma cooling at depth, and (2) which evolved (Si02enriched, MgO-depleted) rock compositions could be produced from the SNC magma, and how these compare with the Pathfinder andesite composition. Finally, we compare the SNC magma compositions to the Mars soil composition in order to determine whether any source other than SNC is required.

Fully automatic segmentation of the femur from 3D-CT images using primitive shape recognition and statistical shape models.

PubMed

Ben Younes, Lassad; Nakajima, Yoshikazu; Saito, Toki

2014-03-01

Femur segmentation is well established and widely used in computer-assisted orthopedic surgery. However, most of the robust segmentation methods such as statistical shape models (SSM) require human intervention to provide an initial position for the SSM. In this paper, we propose to overcome this problem and provide a fully automatic femur segmentation method for CT images based on primitive shape recognition and SSM. Femur segmentation in CT scans was performed using primitive shape recognition based on a robust algorithm such as the Hough transform and RANdom SAmple Consensus. The proposed method is divided into 3 steps: (1) detection of the femoral head as sphere and the femoral shaft as cylinder in the SSM and the CT images, (2) rigid registration between primitives of SSM and CT image to initialize the SSM into the CT image, and (3) fitting of the SSM to the CT image edge using an affine transformation followed by a nonlinear fitting. The automated method provided good results even with a high number of outliers. The difference of segmentation error between the proposed automatic initialization method and a manual initialization method is less than 1 mm. The proposed method detects primitive shape position to initialize the SSM into the target image. Based on primitive shapes, this method overcomes the problem of inter-patient variability. Moreover, the results demonstrate that our method of primitive shape recognition can be used for 3D SSM initialization to achieve fully automatic segmentation of the femur.

Novel population of small tumour-initiating stem cells in the ovaries of women with borderline ovarian cancer

PubMed Central

Virant-Klun, Irma; Stimpfel, Martin

2016-01-01

Small stem cells with diameters of up to 5 μm previously isolated from adult human ovaries indicated pluripotency and germinal lineage, especially primordial germ cells, and developed into primitive oocyte-like cells in vitro. Here, we show that a comparable population of small stem cells can be found in the ovarian tissue of women with borderline ovarian cancer, which, in contrast to small stem cells in “healthy” ovaries, formed spontaneous tumour-like structures and expressed some markers related to pluripotency and germinal lineage. The gene expression profile of these small putative cancer stem cells differed from similar cells sorted from “healthy” ovaries by 132 upregulated and 97 downregulated genes, including some important forkhead box and homeobox genes related to transcription regulation, developmental processes, embryogenesis, and ovarian cancer. These putative cancer stem cells are suggested to be a novel population of ovarian tumour-initiating cells in humans. PMID:27703207

Flow-cytometric separation and enrichment of hepatic progenitor cells in the developing mouse liver.

PubMed

Suzuki, A; Zheng, Y; Kondo, R; Kusakabe, M; Takada, Y; Fukao, K; Nakauchi, H; Taniguchi, H

2000-12-01

Stem cells responsible for tissue maintenance and repair are found in a number of organs. However, hepatic stem cells assumed to play a key role in liver development and regeneration remain to be well characterized. To address this issue, we set up a culture system in which primitive hepatic progenitor cells formed colonies. By combining this culture system with fluorescence-activated cell sorting (FACS), cells forming colonies containing distinct hepatocytes and cholangiocytes were identified in the fetal mouse liver. These cells express both CD49f and CD29 (alpha6 and beta1 integrin subunits), but do not mark for hematopoietic antigens such as CD45, TER119, and c-Kit. When transplanted into the spleen, these cells migrated to the recipient liver and differentiated into liver parenchymal cells. Our data demonstrate that hepatic progenitor cells are enriched by FACS and suggest approaches to supplanting organ allografting and improving artificial-organ hepatic support.

Source characteristics and tectonic setting of mafic-ultramafic intrusions in North Xinjiang, NW China: Insights from the petrology and geochemistry of the Lubei mafic-ultramafic intrusion

NASA Astrophysics Data System (ADS)

Chen, Bao-Yun; Yu, Jin-Jie; Liu, Shuai-Jie

2018-05-01

The newly discovered Lubei sulfide-bearing mafic-ultramafic intrusion forms the western extension of the Huangshan-Jin'erquan mafic-ultramafic intrusion belt in East Tianshan, NW China. The Lubei intrusion comprises hornblende peridotite, lherzolite, and harzburgite in its southern portion, gabbro in its middle portion, and hornblende gabbro in its northern portion. Intrusive relationships indicate that three magma pulses were involved in the formation of the intrusion, and that they were likely evolved from a common primitive magma. Estimated compositions of the Lubei primitive magma are similar to those of island arc calc-alkaline basalt except for the low Na2O and CaO contents of the Lubei primitive magma. This paper reports on the mineral compositions, whole-rock major and trace element contents, and Rb-Sr and Sm-Nd isotopic compositions of the Lubei intrusion, and a zircon LA-MC-ICP-MS U-Pb age for hornblende gabbro. The Lubei intrusion is characterized by enrichment in large-ion lithophile elements, depletion in high-field-strength elements, and marked negative Nb and Ta anomalies, with enrichment in chondrite-normalized light rare earth elements. It exhibits low (87Sr/86Sr)i ratios of 0.70333-0.70636 and low (143Nd/144Nd)i ratios of 0.51214-0.51260, with positive εNd values of +4.01 to +6.33. LA-ICP-MS U-Pb zircon ages yielded a weighted-mean age of 287.9 ± 1.6 Ma for the Lubei intrusion. Contemporaneous mafic-ultramafic intrusions in different tectonic domains in North Xinjiang show similar geological and geochemical signatures to the Lubei intrusion, suggesting a source region of metasomatized mantle previously modified by hydrous fluids from the slab subducted beneath the North Xinjiang region in the early Permian. Metasomatism of the mantle was dominated by hydrous fluids and was related to subduction of the Paleo-Asian oceanic lithosphere during the Paleozoic. Sr-Nd-Pb isotopic compositions suggest that the mantle source was a mixture of depleted mid-ocean-ridge-basalt mantle and enriched-mantle I components. The Permian mafic-ultramafic intrusions in North Xinjiang were formed from tholeiitic basaltic magmas derived from decompression partial melting of the metasomatized mantle in a post-collision extensional tectonic setting. The tholeiitic basaltic magmas are equivalent to the voluminous underplated basaltic magmas that formed during vertical crustal growth of the Central Asian Orogenic Belt in the later Paleozoic.

A Case of Desmoplastic Small Round Cell Tumor.

PubMed

Reisner, David; Brahee, Deborah; Patel, Shweta; Hartman, Matthew

2015-08-01

Desmoplastic small round cell tumor is a rare, aggressive tumor primarily affecting young males. It is considered a childhood cancer, and is characterized by a unique chromosomal translocation which leads to failure to suppress tumor growth. It is classified as a soft tissue sarcoma, sharing some features with other small round cell tumors such as Ewing's Sarcoma and primitive neuroectodermal tumor. Typical imaging findings include multiple heterogeneous, lobular abdominal masses, which can grow very large. Often there is a dominant mass with additional peritoneal, omental, retroperitoneal and retrovesical masses. Prognosis is relatively poor with a 3 year survival rate of 50% in those treated aggressively with surgical resection, chemotherapy, and radiation therapy. The clinical presentation, imaging characteristics and pathology are discussed in regards to a recent case.

Stability of ammonia in the primitive terrestrial atmosphere

NASA Technical Reports Server (NTRS)

Kasting, J. F.

1982-01-01

The rate at which ammonia would have been destroyed in the earth's atmosphere under assumed NH3 mixing ratio conditions of 10 to the -8th to 0.0001 is calculated by a one-dimensional photochemical model, and the destruction rates are compared with possible biotic and abiotic ammonia sources. It is found that, while the mixing ratio of 10 to the -8th needed for the evolution of life could have been maintained by abiotic sources, the value of 0.00001 needed for the production of significant greenhouse warming could not have been sustained abiotically. The increase of atmospheric ammonia due to biological activities during the Archean is also considered lower than the level required for the generation of measurable thermal effects.

Next Generation, 4-D Distributed Modeling and Visualization of Battlefield

DTIC Science & Technology

2006-07-14

accurate. However, the effectiveness of such a view is determined by its usability. If the picture contained all the information that had been...major key to success in such missions is the ability to model real-world urban areas accurately and effectively , so as to support US military mission...primitives (including the standard CG primitives such as plane, cube, wedge, polyhedron, cylinder and sphere, and high-order surface primitives such as

A Guide to FASTGEN Target Geometric Modeling

DTIC Science & Technology

1993-10-01

component part is described in plate mode. These rules apply to all primitives with the exception of rod mode primitives which are always accompanied by a...format. A detailed discussion of the rules for preparing the target description file, where components are described using primitives defined as triangles...NN position is 99, the diameter of a rod mode component is limited to a maximum of 1.98-inches. Theie are several rules and cautions associated with

Hydrostatic calculations of axisymmetric flow and its stability for the AGCE model

NASA Technical Reports Server (NTRS)

Miller, T. L.; Gall, R. L.

1981-01-01

Baroclinic waves in the atmospherics general circulation experiment (AGCE) apparatus by the use of numerical hydrostatic primitive equation models were determined. The calculation is accomplished by using an axisymmetric primitive equation model to compute, for a given set of experimental parameters, a steady state axisymmetric flow and then testing this axisymmetric flow for stability using a linear primitive equation model. Some axisymmetric flows are presented together with preliminary stability calculations.

Cave men: stone tools, Victorian science, and the 'primitive mind' of deep time.

PubMed

Pettitt, Paul B; White, Mark J

2011-03-20

Palaeoanthropology, the study of the evolution of humanity, arose in the nineteenth century. Excavations in Europe uncovered a series of archaeological sediments which provided proof that the antiquity of human life on Earth was far longer than the biblical six thousand years, and by the 1880s authors had constructed a basic paradigm of what 'primitive' human life was like. Here we examine the development of Victorian palaeoanthropology for what it reveals of the development of notions of cognitive evolution. It seems that Victorian specialists rarely addressed cognitive evolution explicitly, although several assumptions were generally made that arose from preconceptions derived from contemporary 'primitive' peoples. We identify three main phases of development of notions of the primitive mind in the period.

Primitive neuroectodermal tumor of the cervix: a case report

PubMed Central

2011-01-01

Introduction Peripheral primitive neuroectodermal tumor of the cervix uteri is extremely rare. Between 1987 and 2010, there were only nine cases reported in the English literature, with considerably different management policies. Case presentation A 45-year-old Iranian woman presented to our facility with a primitive neuroectodermal tumor of the cervix uteri. Her clinical stage IB2 tumor was treated successfully with chemotherapy. Our patient underwent radical hysterectomy. There was no trace of the tumor after four years of follow-up. Conclusions According to current knowledge, primitive neuroectodermal tumors belong to the Ewing's sarcoma family, and the improvement of treatment outcome in our patient was due to dose-intensive neoadjuvant chemotherapy, surgery and consolidation chemotherapy in accordance with the protocol for bony Ewing's sarcoma. PMID:21962148

Insights to primitive replication derived from structures of small oligonucleotides

NASA Technical Reports Server (NTRS)

Smith, G. K.; Fox, G. E.

1995-01-01

Available information on the structure of small oligonucleotides is surveyed. It is observed that even small oligomers typically exhibit defined structures over a wide range of pH and temperature. These structures rely on a plethora of non-standard base-base interactions in addition to the traditional Watson-Crick pairings. Stable duplexes, though typically antiparallel, can be parallel or staggered and perfect complementarity is not essential. These results imply that primitive template directed reactions do not require high fidelity. Hence, the extensive use of Watson-Crick complementarity in genes rather than being a direct consequence of the primitive condensation process, may instead reflect subsequent selection based on the advantage of accuracy in maintaining the primitive genetic machinery once it arose.

Decoding the Regulatory Network for Blood Development from Single-Cell Gene Expression Measurements

PubMed Central

Haghverdi, Laleh; Lilly, Andrew J.; Tanaka, Yosuke; Wilkinson, Adam C.; Buettner, Florian; Macaulay, Iain C.; Jawaid, Wajid; Diamanti, Evangelia; Nishikawa, Shin-Ichi; Piterman, Nir; Kouskoff, Valerie; Theis, Fabian J.; Fisher, Jasmin; Göttgens, Berthold

2015-01-01

Here we report the use of diffusion maps and network synthesis from state transition graphs to better understand developmental pathways from single cell gene expression profiling. We map the progression of mesoderm towards blood in the mouse by single-cell expression analysis of 3,934 cells, capturing cells with blood-forming potential at four sequential developmental stages. By adapting the diffusion plot methodology for dimensionality reduction to single-cell data, we reconstruct the developmental journey to blood at single-cell resolution. Using transitions between individual cellular states as input, we develop a single-cell network synthesis toolkit to generate a computationally executable transcriptional regulatory network model that recapitulates blood development. Model predictions were validated by showing that Sox7 inhibits primitive erythropoiesis, and that Sox and Hox factors control early expression of Erg. We therefore demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the transcriptional programs that control organogenesis. PMID:25664528

A new genus and species of tettigarctid cicada from the early Miocene of New Zealand: Paratettigarcta zealandica (Hemiptera, Auchenorrhyncha, Tettigarctidae)

PubMed Central

Kaulfuss, Uwe; Moulds, Max

2015-01-01

Abstract A new genus and species of primitive cicada (Hemiptera: Tettigarctidae) is described from the early Miocene of southern New Zealand. Paratettigarcta zealandica gen. et sp. n. is the first cicada (Cicadoidea) fossil from New Zealand and exhibits wing venation patterns typical for the subfamily Tettigarctinae. It differs from other fossil taxa and the extant genus Tettigarcta in the early divergence of CuA2 from the nodal line in the forewing, its parallel-sided subcostal cell, the early bifurcation of vein M and long apical cells of the hindwing, and in wing pigmentation patterns. PMID:25829843

A new genus and species of tettigarctid cicada from the early Miocene of New Zealand: Paratettigarctazealandica (Hemiptera, Auchenorrhyncha, Tettigarctidae).

PubMed

Kaulfuss, Uwe; Moulds, Max

2015-01-01

A new genus and species of primitive cicada (Hemiptera: Tettigarctidae) is described from the early Miocene of southern New Zealand. Paratettigarctazealandica gen. et sp. n. is the first cicada (Cicadoidea) fossil from New Zealand and exhibits wing venation patterns typical for the subfamily Tettigarctinae. It differs from other fossil taxa and the extant genus Tettigarcta in the early divergence of CuA2 from the nodal line in the forewing, its parallel-sided subcostal cell, the early bifurcation of vein M and long apical cells of the hindwing, and in wing pigmentation patterns.

Cilengitide in Treating Children With Refractory Primary Brain Tumors

ClinicalTrials.gov

2013-09-27

Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebellar Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Brain Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma

Temozolomide and O6-Benzylguanine in Treating Children With Recurrent Brain Tumors

ClinicalTrials.gov

2013-09-27

Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebellar Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma

Lenalidomide in Treating Young Patients With Recurrent, Progressive, or Refractory CNS Tumors

ClinicalTrials.gov

2013-09-27

Childhood Atypical Teratoid/Rhabdoid Tumor; Childhood Central Nervous System Germ Cell Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Ependymoblastoma; Childhood Grade I Meningioma; Childhood Grade II Meningioma; Childhood Grade III Meningioma; Childhood High-grade Cerebellar Astrocytoma; Childhood High-grade Cerebral Astrocytoma; Childhood Infratentorial Ependymoma; Childhood Low-grade Cerebellar Astrocytoma; Childhood Low-grade Cerebral Astrocytoma; Childhood Medulloepithelioma; Childhood Mixed Glioma; Childhood Oligodendroglioma; Childhood Supratentorial Ependymoma; Recurrent Childhood Brain Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma

Vemurafenib in Treating Patients With Relapsed or Refractory Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With BRAF V600 Mutations (A Pediatric MATCH Treatment Trial)

ClinicalTrials.gov

2018-06-25

Advanced Malignant Solid Neoplasm; Ann Arbor Stage III Childhood Non-Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Non-Hodgkin Lymphoma; BRAF NP_004324.2:p.V600X; Ependymoma; Ewing Sarcoma; Hepatoblastoma; Histiocytosis; Langerhans Cell Histiocytosis; Malignant Germ Cell Tumor; Malignant Glioma; Osteosarcoma; Peripheral Primitive Neuroectodermal Tumor; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Childhood Non-Hodgkin Lymphoma; Recurrent Malignant Solid Neoplasm; Recurrent Neuroblastoma; Refractory Central Nervous System Neoplasm; Refractory Malignant Solid Neoplasm; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Rhabdoid Tumor; Rhabdomyosarcoma; Soft Tissue Sarcoma; Wilms Tumor

Intrinsic factors and the embryonic environment influence the formation of extragonadal teratomas during gestation.

PubMed

Economou, Constantinos; Tsakiridis, Anestis; Wymeersch, Filip J; Gordon-Keylock, Sabrina; Dewhurst, Robert E; Fisher, Dawn; Medvinsky, Alexander; Smith, Andrew J H; Wilson, Valerie

2015-10-09

Pluripotent cells are present in early embryos until the levels of the pluripotency regulator Oct4 drop at the beginning of somitogenesis. Elevating Oct4 levels in explanted post-pluripotent cells in vitro restores their pluripotency. Cultured pluripotent cells can participate in normal development when introduced into host embryos up to the end of gastrulation. In contrast, pluripotent cells efficiently seed malignant teratocarcinomas in adult animals. In humans, extragonadal teratomas and teratocarcinomas are most frequently found in the sacrococcygeal region of neonates, suggesting that these tumours originate from cells in the posterior of the embryo that either reactivate or fail to switch off their pluripotent status. However, experimental models for the persistence or reactivation of pluripotency during embryonic development are lacking. We manually injected embryonic stem cells into conceptuses at E9.5 to test whether the presence of pluripotent cells at this stage correlates with teratocarcinoma formation. We then examined the effects of reactivating embryonic Oct4 expression ubiquitously or in combination with Nanog within the primitive streak (PS)/tail bud (TB) using a transgenic mouse line and embryo chimeras carrying a PS/TB-specific heterologous gene expression cassette respectively. Here, we show that pluripotent cells seed teratomas in post-gastrulation embryos. However, at these stages, induced ubiquitous expression of Oct4 does not lead to restoration of pluripotency (indicated by Nanog expression) and tumour formation in utero, but instead causes a severe phenotype in the extending anteroposterior axis. Use of a more restricted T(Bra) promoter transgenic system enabling inducible ectopic expression of Oct4 and Nanog specifically in the posteriorly-located primitive streak (PS) and tail bud (TB) led to similar axial malformations to those induced by Oct4 alone. These cells underwent induction of pluripotency marker expression in Epiblast Stem Cell (EpiSC) explants derived from somitogenesis-stage embryos, but no teratocarcinoma formation was observed in vivo. Our findings show that although pluripotent cells with teratocarcinogenic potential can be produced in vitro by the overexpression of pluripotency regulators in explanted somitogenesis-stage somatic cells, the in vivo induction of these genes does not yield tumours. This suggests a restrictive regulatory role of the embryonic microenvironment in the induction of pluripotency.

ARCGRAPH SYSTEM - AMES RESEARCH GRAPHICS SYSTEM

NASA Technical Reports Server (NTRS)

Hibbard, E. A.

1994-01-01

Ames Research Graphics System, ARCGRAPH, is a collection of libraries and utilities which assist researchers in generating, manipulating, and visualizing graphical data. In addition, ARCGRAPH defines a metafile format that contains device independent graphical data. This file format is used with various computer graphics manipulation and animation packages at Ames, including SURF (COSMIC Program ARC-12381) and GAS (COSMIC Program ARC-12379). In its full configuration, the ARCGRAPH system consists of a two stage pipeline which may be used to output graphical primitives. Stage one is associated with the graphical primitives (i.e. moves, draws, color, etc.) along with the creation and manipulation of the metafiles. Five distinct data filters make up stage one. They are: 1) PLO which handles all 2D vector primitives, 2) POL which handles all 3D polygonal primitives, 3) RAS which handles all 2D raster primitives, 4) VEC which handles all 3D raster primitives, and 5) PO2 which handles all 2D polygonal primitives. Stage two is associated with the process of displaying graphical primitives on a device. To generate the various graphical primitives, create and reprocess ARCGRAPH metafiles, and access the device drivers in the VDI (Video Device Interface) library, users link their applications to ARCGRAPH's GRAFIX library routines. Both FORTRAN and C language versions of the GRAFIX and VDI libraries exist for enhanced portability within these respective programming environments. The ARCGRAPH libraries were developed on a VAX running VMS. Minor documented modification of various routines, however, allows the system to run on the following computers: Cray X-MP running COS (no C version); Cray 2 running UNICOS; DEC VAX running BSD 4.3 UNIX, or Ultrix; SGI IRIS Turbo running GL2-W3.5 and GL2-W3.6; Convex C1 running UNIX; Amhdahl 5840 running UTS; Alliant FX8 running UNIX; Sun 3/160 running UNIX (no native device driver); Stellar GS1000 running Stellex (no native device driver); and an SGI IRIS 4D running IRIX (no native device driver). Currently with version 7.0 of ARCGRAPH, the VDI library supports the following output devices: A VT100 terminal with a RETRO-GRAPHICS board installed, a VT240 using the Tektronix 4010 emulation capability, an SGI IRIS turbo using the native GL2 library, a Tektronix 4010, a Tektronix 4105, and the Tektronix 4014. ARCGRAPH version 7.0 was developed in 1988.

Retroviral envelope syncytin capture in an ancestrally diverged mammalian clade for placentation in the primitive Afrotherian tenrecs

PubMed Central

Cornelis, Guillaume; Vernochet, Cécile; Malicorne, Sébastien; Souquere, Sylvie; Tzika, Athanasia C.; Goodman, Steven M.; Catzeflis, François; Robinson, Terence J.; Milinkovitch, Michel C.; Pierron, Gérard; Heidmann, Odile; Dupressoir, Anne; Heidmann, Thierry

2014-01-01

Syncytins are fusogenic envelope (env) genes of retroviral origin that have been captured for a function in placentation. Syncytins have been identified in Euarchontoglires (primates, rodents, Leporidae) and Laurasiatheria (Carnivora, ruminants) placental mammals. Here, we searched for similar genes in species that retained characteristic features of primitive mammals, namely the Malagasy and mainland African Tenrecidae. They belong to the superorder Afrotheria, an early lineage that diverged from Euarchotonglires and Laurasiatheria 100 Mya, during the Cretaceous terrestrial revolution. An in silico search for env genes with full coding capacity within a Tenrecidae genome identified several candidates, with one displaying placenta-specific expression as revealed by RT-PCR analysis of a large panel of Setifer setosus tissues. Cloning of this endogenous retroviral env gene demonstrated fusogenicity in an ex vivo cell–cell fusion assay on a panel of mammalian cells. Refined analysis of placental architecture and ultrastructure combined with in situ hybridization demonstrated specific expression of the gene in multinucleate cellular masses and layers at the materno–fetal interface, consistent with a role in syncytium formation. This gene, which we named “syncytin-Ten1,” is conserved among Tenrecidae, with evidence of purifying selection and conservation of fusogenic activity. To our knowledge, it is the first syncytin identified to date within the ancestrally diverged Afrotheria superorder. PMID:25267646

Evolutionary and Functional Relationships of B Cells from Fish and Mammals: Insights into their Novel Roles in Phagocytosis and Presentation of Particulate Antigen

PubMed Central

Sunyer, J. Oriol

2012-01-01

The evolutionary origins of Ig-producing B cells appear to be linked to the emergence of fish in this planet. There are three major classes of living fish species, which from most primitive to modern they are referred to as agnathan (e.g., lampreys), Chondrichthyes (e.g., sharks), and teleost fish (e.g., rainbow trout). Agnathans do not have immunoglobulin-producing B cells, however these fish contain a subset of lymphocytes-like cells producing type B variable lymphocyte receptors (VLRBs) that appear to act as functional analogs of immunoglobulins. Chondrichthyes fish represent the most primitive living species containing bona-fide immunoglobulin-producing B cells. Their B cells are known to secrete three types of antibodies, IgM, IgW and IgNAR. Teleost fish are also called bony fish since they represent the most ancient living species containing true bones. Teleost B cells produce three different immunoglobulin isotypes, IgM, IgD and the recently described IgT. While teleost IgM is the principal player in systemic immunity, IgT appears to be a teleost immunoglobulin class specialized in mucosal immune responses. Thus far, three major B cell lineages have been described in teleost, those expressing either IgT or IgD, and the most common lineage which co-expresses IgD and IgM. A few years ago, the study of teleost fish B cells revealed for the first time in vertebrates the existence of B cell subsets with phagocytic and intracellular bactericidal capacities. This finding represented a paradigm shift as professional phagocytosis was believed to be exclusively performed by some cells of the myeloid lineage (i.e., macrophages, monocytes, neutrophils). This phagocytic capacity was also found in amphibians and reptiles, suggesting that this innate capacity was evolutionarily conserved in certain B cell subsets of vertebrates. Recently, the existence of subsets of B cells with phagocytic and bactericidal abilities have also been confirmed in mammals. Moreover, it has been shown that phagocytic B-1 B cells have a potent ability to present particulate antigen to CD4+ T cells. Thus, studies carried out originally on fish B cells have lead to the discovery of new innate and adaptive roles of B cells in mammals. This review will concentrate on the evolutionary and functional relationships of fish and mammalian B cells, focusing mainly on the newly discovered roles of these cells in phagocytosis, intracellular killing and presentation of particulate antigen. PMID:22394174

Preclinical modeling highlights the therapeutic potential of hematopoietic stem cell gene editing for correction of SCID-X1.

PubMed

Schiroli, Giulia; Ferrari, Samuele; Conway, Anthony; Jacob, Aurelien; Capo, Valentina; Albano, Luisa; Plati, Tiziana; Castiello, Maria C; Sanvito, Francesca; Gennery, Andrew R; Bovolenta, Chiara; Palchaudhuri, Rahul; Scadden, David T; Holmes, Michael C; Villa, Anna; Sitia, Giovanni; Lombardo, Angelo; Genovese, Pietro; Naldini, Luigi

2017-10-11

Targeted genome editing in hematopoietic stem/progenitor cells (HSPCs) is an attractive strategy for treating immunohematological diseases. However, the limited efficiency of homology-directed editing in primitive HSPCs constrains the yield of corrected cells and might affect the feasibility and safety of clinical translation. These concerns need to be addressed in stringent preclinical models and overcome by developing more efficient editing methods. We generated a humanized X-linked severe combined immunodeficiency (SCID-X1) mouse model and evaluated the efficacy and safety of hematopoietic reconstitution from limited input of functional HSPCs, establishing thresholds for full correction upon different types of conditioning. Unexpectedly, conditioning before HSPC infusion was required to protect the mice from lymphoma developing when transplanting small numbers of progenitors. We then designed a one-size-fits-all IL2RG (interleukin-2 receptor common γ-chain) gene correction strategy and, using the same reagents suitable for correction of human HSPC, validated the edited human gene in the disease model in vivo, providing evidence of targeted gene editing in mouse HSPCs and demonstrating the functionality of the IL2RG -edited lymphoid progeny. Finally, we optimized editing reagents and protocol for human HSPCs and attained the threshold of IL2RG editing in long-term repopulating cells predicted to safely rescue the disease, using clinically relevant HSPC sources and highly specific zinc finger nucleases or CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9). Overall, our work establishes the rationale and guiding principles for clinical translation of SCID-X1 gene editing and provides a framework for developing gene correction for other diseases. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Melt extraction and mantle source at a Southwest Indian Ridge Dragon Bone amagmatic segment on the Marion Rise

NASA Astrophysics Data System (ADS)

Gao, Changgui; Dick, Henry J. B.; Liu, Yang; Zhou, Huaiyang

2016-03-01

This paper works on the trace and major element compositions of spatially associated basalts and peridotites from the Dragon Bone amagmatic ridge segment at the eastern flank of the Marion Platform on the ultraslow spreading Southwest Indian Ridge. The rare earth element compositions of basalts do not match the pre-alteration Dragon Bone peridotite compositions, but can be modeled by about 5 to 10% non-modal batch equilibrium melting from a DMM source. The Dragon Bone peridotites are clinopyroxene-poor harzburgite with average spinel Cr# 27.7. The spinel Cr# indicates a moderate degree of melting. However, CaO and Al2O3 of the peridotites are lower than other abyssal peridotites at the same Mg# and extent of melting. This requires a pyroxene-poor initial mantle source composition compared to either hypothetical primitive upper mantle or depleted MORB mantle sources. We suggest a hydrous melting of the initial Dragon Bone mantle source, as wet melting depletes pyroxene faster than dry. According to the rare earth element patterns, the Dragon Bone peridotites are divided into two groups. Heavy REE in Group 1 are extremely fractionated from middle REE, which can be modeled by 7% fractional melting in the garnet stability field and another 12.5 to 13.5% in the spinel stability field from depleted and primitive upper mantle sources, respectively. Heavy REE in Group 2 are slightly fractionated from middle REE, which can be modeled by 15 to 20% fractional melting in the spinel stability field from a depleted mantle source. Both groups show similar melting degree to other abyssal peridotites. If all the melt extraction occurred at the middle oceanic ridge where the peridotites were dredged, a normal 6 km thick oceanic crust is expected at the Dragon Bone segment. However, the Dragon Bone peridotites are exposed in an amagmatic ridge segment where only scattered pillow basalts lie on a partially serpentinized mantle pavement. Thus their depletion requires an earlier melting occurred at other place. Considering the hydrous melting of the initial Dragon Bone mantle source, we suggest the earlier melting event occurred in an arc terrain, prior to or during the closure of the Mozambique Ocean in the Neproterozoic, and the subsequent assembly of Gondwana. Then, the Al2O3 depleted and thus buoyant peridotites became the MORB source for Southwest Indian Ridge and formed the Marion Rise during the Gondwana breakup.

UNCOMPAHGRE PRIMITIVE AREA, COLORADO.

USGS Publications Warehouse

Luedke, R.G.; Sheridan, M.J.

1984-01-01

A mineral-resource study was made of that part of the Uncompahgre National Forest, Colorado constituting the officially designated primitive area. Because the primitive area and its southern border zone contained operating mines producing gold, silver, copper, lead, zinc, and minor amounts of a few other metals, and had been a part of a highly productive mining region, the area was concluded to have large segments of both probable and substantiated mineral-resource potential. No energy resources were identified in the study.

Primitive myxoid mesenchymal tumor of infancy in a preterm infant.

PubMed

Lam, Joseph; Lara-Corrales, Irene; Cammisuli, Salvatore; Somers, Gino R; Pope, Elena

2010-01-01

Primitive myxoid mesenchymal tumor of infancy is a recently recognized entity that has been added to the differential diagnosis of myxoid tumors of the soft tissue. Few cases have been reported of this entity in the literature, but none presenting in a preterm infant. We present the case and clinical course of a preterm boy with a primitive myxoid mesenchymal tumor of infancy that occurred following excision of a congenital juvenile xanthogranuloma. © 2010 Wiley Periodicals, Inc.

HIGH UINTAS PRIMITIVE AREA, UTAH.

USGS Publications Warehouse

Crittenden, Max D.; Sheridan, Michael J.

1984-01-01

Mineral surveys in the High Uintas Primitive Area, Utah and the additions subsequently proposed concluded that the area has little promise for mineral resources. Of the areas around the fringes, a strip along the north flank fault can be classed as having probable energy-resource potential for oil and gas. The oil and gas potential could be tested by additional seismic studies followed by drilling. Much of the necessary information probably could be obtained without drilling within the primitive area itself.

Intrapartum Synthetic Oxytocin Reduce the Expression of Primitive Reflexes Associated with Breastfeeding

PubMed Central

Olza Fernández, Ibone; Malalana Martínez, Ana M.; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

2015-01-01

Abstract Aim: Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. Materials and Methods: A cohort prospective study was conducted at a tertiary hospital. Mother–infant dyads who received intrapartum oxytocin (n=53) were compared with mother–infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. Results: The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Conclusions: Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent. PMID:25785487

Adiabatic gate teleportation.

PubMed

Bacon, Dave; Flammia, Steven T

2009-09-18

The difficulty in producing precisely timed and controlled quantum gates is a significant source of error in many physical implementations of quantum computers. Here we introduce a simple universal primitive, adiabatic gate teleportation, which is robust to timing errors and many control errors and maintains a constant energy gap throughout the computation above a degenerate ground state space. This construction allows for geometric robustness based upon the control of two independent qubit interactions. Further, our piecewise adiabatic evolution easily relates to the quantum circuit model, enabling the use of standard methods from fault-tolerance theory for establishing thresholds.

Stardust in meteorites.

PubMed

Davis, Andrew M

2011-11-29

Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars.

Stardust in meteorites

PubMed Central

Davis, Andrew M.

2011-01-01

Primitive meteorites, interplanetary dust particles, and comets contain dust grains that formed around stars that lived their lives before the solar system formed. These remarkable objects have been intensively studied since their discovery a little over twenty years ago and they provide samples of other stars that can be studied in the laboratory in exquisite detail with modern analytical tools. The properties of stardust grains are used to constrain models of nucleosynthesis in red giant stars and supernovae, the dominant sources of dust grains that are recycled into the interstellar medium by stars. PMID:22106261

A subjective study and an objective metric to quantify the granularity level of textures

NASA Astrophysics Data System (ADS)

Subedar, Mahesh M.; Karam, Lina J.

2015-03-01

Texture granularity is an important visual characteristic that is useful in a variety of applications, including analysis, recognition, and compression, to name a few. A texture granularity measure can be used to quantify the perceived level of texture granularity. The granularity level of the textures is influenced by the size of the texture primitives. A primitive is defined as the smallest recognizable repetitive object in the texture. If the texture has large primitives then the perceived granularity level tends to be lower as compared to a texture with smaller primitives. In this work we are presenting a texture granularity database referred as GranTEX which consists of 30 textures with varying levels of primitive sizes and granularity levels. The GranTEX database consists of both natural and man-made textures. A subjective study is conducted to measure the perceived granularity level of textures present in the GranTEX database. An objective metric that automatically measures the perceived granularity level of textures is also presented as part of this work. It is shown that the proposed granularity metric correlates well with the subjective granularity scores.

Oocyte formation by mitotically active germ cells purified from ovaries of reproductive-age women.

PubMed

White, Yvonne A R; Woods, Dori C; Takai, Yasushi; Ishihara, Osamu; Seki, Hiroyuki; Tilly, Jonathan L

2012-02-26

Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a fluorescence-activated cell sorting-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically active cells that have a gene expression profile that is consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and can spontaneously generate 35- to 50-μm oocytes, as determined by morphology, gene expression and haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1-2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, similar to adult mice, possess rare mitotically active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo.

Melatonin and its precursors in Y79 human retinoblastoma cells - Effect of sodium butyrate

NASA Technical Reports Server (NTRS)

Deng, Mei H.; Lopez G.-Coviella, Ignacio; Lynch, Harry J.; Wurtman, Richard J.

1991-01-01

We studied the release of melatonin and the production of its precursors, 5-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for three days. This protocol dramatically increased the release of melatonin, and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine or L-DOPA markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 ceils.

Mammary stem cells: angels or demons in mammary gland?

PubMed

Chen, Xueman; Liu, Qiang; Song, Erwei

2017-01-01

A highly dynamic development process exits within the epithelia of mammary gland, featuring morphogenetic variation during puberty, pregnancy, lactation, and regression. The identification of mammary stem cells (MaSCs) via lineage-tracing studies has substantiated a hierarchical organization of the mammary epithelia. A single MaSC is capable of reconstituting the entirely functional mammary gland upon orthotopic transplantation. Although different mammary cell subpopulations can be candidate cells-of-origin for distinct breast tumor subtypes, it still lacks experimental proofs whether MaSCs, the most primitive cells, are the 'seeds' of malignant transformation during most, if not all, tumorigenesis in the breast. Here, we review current knowledge of mammary epithelial hierarchy, highlighting the roles of mammary stem/progenitor cells and breast cancer stem cells (BCSCs) along with their key molecular regulators in organ development and cancer evolution. Clarifying these issues will pave the way for developing novel interventions toward stem/progenitor cells in either prevention or treatment of breast cancer (BrCa).

Mammary stem cells: angels or demons in mammary gland?

PubMed Central

Chen, Xueman; Liu, Qiang; Song, Erwei

2017-01-01

A highly dynamic development process exits within the epithelia of mammary gland, featuring morphogenetic variation during puberty, pregnancy, lactation, and regression. The identification of mammary stem cells (MaSCs) via lineage-tracing studies has substantiated a hierarchical organization of the mammary epithelia. A single MaSC is capable of reconstituting the entirely functional mammary gland upon orthotopic transplantation. Although different mammary cell subpopulations can be candidate cells-of-origin for distinct breast tumor subtypes, it still lacks experimental proofs whether MaSCs, the most primitive cells, are the ‘seeds’ of malignant transformation during most, if not all, tumorigenesis in the breast. Here, we review current knowledge of mammary epithelial hierarchy, highlighting the roles of mammary stem/progenitor cells and breast cancer stem cells (BCSCs) along with their key molecular regulators in organ development and cancer evolution. Clarifying these issues will pave the way for developing novel interventions toward stem/progenitor cells in either prevention or treatment of breast cancer (BrCa). PMID:29263909

Pluripotent Stem Cells in Research and Treatment of Hemoglobinopathies

PubMed Central

Arora, Natasha; Daley, George Q.

2012-01-01

Pluripotent stem cells (PSCs) hold great promise for research and treatment of hemoglobinopathies. In principle, patient-specific induced pluripotent stem cells could be derived from a blood sample, genetically corrected to repair the disease-causing mutation, differentiated into hematopoietic stem cells (HSCs), and returned to the patient to provide a cure through autologous gene and cell therapy. However, there are many challenges at each step of this complex treatment paradigm. Gene repair is currently inefficient in stem cells, but use of zinc finger nucleases and transcription activator-like effector nucleases appear to be a major advance. To date, no successful protocol exists for differentiating PSCs into definitive HSCs. PSCs can be directly differentiated into primitive red blood cells, but not yet in sufficient numbers to enable treating patients, and the cost of clinical scale differentiation is prohibitively expensive with current differentiation methods and efficiencies. Here we review the progress, promise, and remaining hurdles in realizing the potential of PSCs for cell therapy. PMID:22474618

Level Zero Trigger Processor for the ultra rare kaon decay experiment: NA62

NASA Astrophysics Data System (ADS)

Soldi, Dario; Chiozzi, S.; Gamberini, E.; Gianoli, A.; Mila, G.; Neri, I.; Petrucci, F.

2017-02-01

The NA62 experiment is designed to measure the (ultra-)rare decay K+ →π+ ν ν bar branching ratio with a precision of ∼ 10 % at the CERN Super Proton Synchrotron (SPS). The L0 Trigger Processor (L0TP) is the lowest level system of the trigger chain. It is hardware implemented using programmable logic. The architecture of the L0TP is completely new for a high energy physics experiment. It is fully digital, based on a standard gigabit ethernet communication between detectors and L0TP Board. The L0TP Board is a commercial development board, Terasic DE4, mounting an Altera Stratix IV FPGA. The primitives generated by sub-detectors are sent asynchronously using the UDP protocol to the L0TP during the entire beam spill period (about 5 seconds). The L0TP realigns in time the primitives coming from 7 different sources and manages the information of the time plus all the characteristics of the event as energy, multiplicity and position of hits in order to select good events with a comparison with preset masks. It should guarantee a maximum latency of 1 ms. The maximum input rate is 10 MHz for each sub-detector, while the design maximum output trigger rate is 1 MHz. A complete trigger-less parasitic acquisition of the primitives is possible using mirroring switches to monitor the L0 behavior. A first version of the L0TP was commissioned during the 2014 NA62 pilot run and it is used in the current data taking. A description of the trigger algorithm is here presented.

Accurate determination of lattice parameters based on Niggli reduced cell theory by using digitized electron diffraction micrograph.

PubMed

Yang, Yi; Cai, Canying; Lin, Jianguo; Gong, Lunjun; Yang, Qibin

2017-05-01

In this paper, we used Niggli reduced cell theory to determine lattice constants of a micro/nano crystal by using electron diffraction patterns. The Niggli reduced cell method enhanced the accuracy of lattice constant measurement obviously, because the lengths and the angles of lattice vectors of a primitive cell can be measured directly on the electron micrographs instead of a double tilt holder. With the aid of digitized algorithm and least square optimization by using three digitized micrographs, a valid reciprocal Niggli reduced cell number can be obtained. Thus a reciprocal and real Bravais lattices are acquired. The results of three examples, i.e., Mg 4 Zn 7 , an unknown phase (Precipitate phase in nickel-base superalloy) and Ba 4 Ti 13 O 30 showed that the maximum errors are 1.6% for lengths and are 0.3% for angles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eliminating Cancer Stem Cells by Targeting Embryonic Signaling Pathways.

PubMed

Oren, Ohad; Smith, B Douglas

2017-02-01

Dramatic advances have been made in the understanding of cancer over the past decade. Prime among those are better appreciation of the biology of cancer and the development of targeted therapies. Despite these improvements, however, most tumors remain refractory to anti-cancer medications and frequently recur. Cancer Stem Cells (CSCs), which in some cases express markers of pluripotency (e.g., Oct-4), share many of the molecular features of normal stem cells. These cells have been hypothesised to play a role in tumor resistance and relapse. They exhibit dependence on many primitive regulatory pathways and may be best viewed in the context of embryonic signaling pathways. In this article, we review important embryonic signaling cascades and their differential expression in CSCs. We also discuss these pathways as actionable targets for novel therapies in hopes that eliminating cancer stem cells will lead to an improvement in overall survival for patients.

Multiscale Modeling of Cardiac Cellular Energetics

PubMed Central

BASSINGTHWAIGHTE, JAMES B.; CHIZECK, HOWARD J.; ATLAS, LES E.; QIAN, HONG

2010-01-01

Multiscale modeling is essential to integrating knowledge of human physiology starting from genomics, molecular biology, and the environment through the levels of cells, tissues, and organs all the way to integrated systems behavior. The lowest levels concern biophysical and biochemical events. The higher levels of organization in tissues, organs, and organism are complex, representing the dynamically varying behavior of billions of cells interacting together. Models integrating cellular events into tissue and organ behavior are forced to resort to simplifications to minimize computational complexity, thus reducing the model’s ability to respond correctly to dynamic changes in external conditions. Adjustments at protein and gene regulatory levels shortchange the simplified higher-level representations. Our cell primitive is composed of a set of subcellular modules, each defining an intracellular function (action potential, tricarboxylic acid cycle, oxidative phosphorylation, glycolysis, calcium cycling, contraction, etc.), composing what we call the “eternal cell,” which assumes that there is neither proteolysis nor protein synthesis. Within the modules are elements describing each particular component (i.e., enzymatic reactions of assorted types, transporters, ionic channels, binding sites, etc.). Cell subregions are stirred tanks, linked by diffusional or transporter-mediated exchange. The modeling uses ordinary differential equations rather than stochastic or partial differential equations. This basic model is regarded as a primitive upon which to build models encompassing gene regulation, signaling, and long-term adaptations in structure and function. During simulation, simpler forms of the model are used, when possible, to reduce computation. However, when this results in error, the more complex and detailed modules and elements need to be employed to improve model realism. The processes of error recognition and of mapping between different levels of model form complexity are challenging but are essential for successful modeling of large-scale systems in reasonable time. Currently there is to this end no established methodology from computational sciences. PMID:16093514

Primitive African Medical Lore and Witchcraft *

PubMed Central

Thompson, Ethel E.

1965-01-01

This article presents a comprehensive study of the methods, practices, equipment, and paraphernalia of African witch doctors in carrying out primitive medical practices. The chief tribes studied are the Azandes of the Sudan, the Manos of Liberia, the Congo tribes, the Bundas of Angola, and the Zulus and other Bantu tribes of South Africa. Primitive beliefs and customs are discussed only insofar as they have a direct bearing on medical practices. The medical practices considered deal mainly with the application of general remedies for ailments and diseases, but certain specialized fields such as obstetrics, surgery, treatment for fractures, and dentistry are also included. Primitive medicaments are presented with reference to their application for various illnesses. An alphabetical list of these medicaments is given at the end of the article. PMID:14223742

Carotid-vertebrobasilar Anastomoses with Reference to Their Segmental Property.

PubMed

Namba, Katsunari

2017-06-15

The primitive carotid-vertebrobasilar anastomoses are primitive embryonic cerebral vessels that temporarily provide arterial supply from the internal carotid artery to the longitudinal neural artery, the future vertebrobasilar artery in the hindbrain. Four types known are the trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries. The arteries are accompanied by their corresponding nerves and resemble an intersegmental pattern. These vessels exist in the very early period of cerebral arterial development and rapidly involute within a week. Occasionally, persistence of the carotid to vertebrobasilar anastomosis is discovered in the adult period, and is considered as the vestige of the corresponding primitive embryonic vessel. The embryonic development and the segmental property of the primitive carotid-vertebrobasilar anastomoses are discussed. This is followed by a brief description of the persisting anastomoses in adults.

Impact of Discrete Corrections in a Modular Approach for Trajectory Generation in Quadruped Robots

NASA Astrophysics Data System (ADS)

Pinto, Carla M. A.; Santos, Cristina P.; Rocha, Diana; Matos, Vítor

2011-09-01

Online generation of trajectories in robots is a very complex task that involves the combination of different types of movements, i.e., distinct motor primitives. The later are used to model complex behaviors in robots, such as locomotion in irregular terrain and obstacle avoidance. In this paper, we consider two motor primitives: rhythmic and discrete. We study the effect on the robots' gaits of superimposing the two motor primitives, considering two distinct types of coupling. Additionally, we simulate two scenarios, where the discrete primitive is inserted in all of the four limbs, or is inserted in ipsilateral pairs of limbs. Numerical results show that amplitude and frequency of the periodic solutions, corresponding to the gaits trot and pace, are almost constant for diffusive and synaptic couplings.

Boninite-like intraplate magmas from Manihiki Plateau require ultra-depleted and enriched source components

PubMed Central

Golowin, Roman; Portnyagin, Maxim; Hoernle, Kaj; Hauff, Folkmar; Gurenko, Andrey; Garbe-Schönberg, Dieter; Werner, Reinhard; Turner, Simon

2017-01-01

The Ontong Java and Manihiki oceanic plateaus are believed to have formed through high-degree melting of a mantle plume head. Boninite-like, low-Ti basement rocks at Manihiki, however, imply a more complex magma genesis compared with Ontong Java basement lavas that can be generated by ∼30% melting of a primitive mantle source. Here we show that the trace element and isotope compositions of low-Ti Manihiki rocks can best be explained by re-melting of an ultra-depleted source (possibly a common mantle component in the Ontong Java and Manihiki plume sources) re-enriched by ≤1% of an ocean-island-basalt-like melt component. Unlike boninites formed via hydrous flux melting of refractory mantle at subduction zones, these boninite-like intraplate rocks formed through adiabatic decompression melting of refractory plume material that has been metasomatized by ocean-island-basalt-like melts. Our results suggest that caution is required before assuming all Archaean boninites were formed in association with subduction processes. PMID:28181497

JAK2 mutation in a patient with CLL with coexistent myeloproliferative neoplasm (MPN).

PubMed

Kodali, Srinivas; Chen, Chi; Rathnasabapathy, Chenthilmurugan; Wang, Jen Chin

2009-12-01

JAK2 mutation has not been described in patients with chronic lymphocytic leukemia (CLL). We found JAK2 mutation in a patient with CLL and coexisting myeloproliferative neoplasm (MPN). In this patient, we demonstrated the presence of the JAK2 mutation in CD34(+) progenitor cells, myeloid lineage cells, megakaryocytes, B lymphocytes but not in T lymphocytes. This case represents the first case report of JAK2 mutation in CLL and may also suggest that, JAK2 mutation most likely represents a secondary event from primary gene mutations involving the primitive stem cells which give rise to MPN and CLL. Furthermore, in this case, we believe that we are the first to demonstrate that JAK2 mutation in myeloid and B lymphoid cells but not T lymphocytes in a case of coexisting CLL and MPN.

The human phosphotyrosine signaling network: Evolution and hotspots of hijacking in cancer

PubMed Central

Li, Lei; Tibiche, Chabane; Fu, Cong; Kaneko, Tomonori; Moran, Michael F.; Schiller, Martin R.; Li, Shawn Shun-Cheng; Wang, Edwin

2012-01-01

Phosphotyrosine (pTyr) signaling, which plays a central role in cell–cell and cell–environment interactions, has been considered to be an evolutionary innovation in multicellular metazoans. However, neither the emergence nor the evolution of the human pTyr signaling system is currently understood. Tyrosine kinase (TK) circuits, each of which consists of a TK writer, a kinase substrate, and a related reader, such as Src homology (SH) 2 domains and pTyr-binding (PTB) domains, comprise the core machinery of the pTyr signaling network. In this study, we analyzed the evolutionary trajectories of 583 literature-derived and 50,000 computationally predicted human TK circuits in 19 representative eukaryotic species and assigned their evolutionary origins. We found that human TK circuits for intracellular pTyr signaling originated largely from primitive organisms, whereas the inter- or extracellular signaling circuits experienced significant expansion in the bilaterian lineage through the “back-wiring” of newly evolved kinases to primitive substrates and SH2/PTB domains. Conversely, the TK circuits that are involved in tissue-specific signaling evolved mainly in vertebrates by the back-wiring of vertebrate substrates to primitive kinases and SH2/PTB domains. Importantly, we found that cancer signaling preferentially employs the pTyr sites, which are linked to more TK circuits. Our work provides insights into the evolutionary paths of the human pTyr signaling circuits and suggests the use of a network approach for cancer intervention through the targeting of key pTyr sites and their associated signaling hubs in the network. PMID:22194470

Visualization of Microbial Biomarkers by Scanning Electron Microscopy

NASA Technical Reports Server (NTRS)

Wainwright, Norman R.; Allen, Carlton C.; Child, Alice

2001-01-01

We are developing tools to link the biochemical structure of selected biomarkers with putative biogenic structures observed in mineralized samples. The detection of evidence of life on Mars and other planets will rely on methods that can discriminate compounds formed exclusively by living organisms. While biogenic compounds, such as amino acids and nucleotides have been discovered in extraterrestrial sources, such as meteorites and comets, their formation can be explained by abiotic means. The formation of cellular structures, or more elaborate organic molecules, such as complex lipids, proteins or nucleic acids, however, is strongly correlated to the presence of even the most primitive life processes. Recent evidence lends support to the hypothesis that life may have once existed on Mars. Carbonate globules and ppm concentrations of polycyclic aromatic hydrocarbons (PAHs) have been described in ALH84001, a meteorite originating from Mars ejecta captured by Earth over 13,000 years ago. The localized high concentration of PAHs that follow an increasing gradient from the intact fusion crust towards the interior corresponds to microgram quantities of hydrocarbon. Even though ALH84001 and other similar meteorites have withstood the forces capable of ejecting rock through Mars' escape velocity, upon entering Earth's atmosphere, their core temperatures are likely not to have been raised significantly, as evidenced by the survival of remanent magnetic signatures. Ideal biomarkers of ancient or modern biological life would include molecules that are (or were) pervasive and highly resistant to degradation. Also, requisite methods of detection should be simple, extremely sensitive and broadly inclusive (NASA SP-530). Lipopolysaccharide (LPS), peptidoglycan or pseudopeptidoglycan and beta-glucan are microbial cell wall components which together cover the entire microbial spectrum of eubacteria, archea and fungi. They are all remarkably resistant to thermal degradation. Fortunately, many antimicrobial defense systems of higher organisms require sensitive detection to combat microbial pathogens. We employ here the primitive immune system of the evolutionarily ancient horseshoe crab, Limulus polyphemus. This species relies on multi-enzyme signal amplification detection of cell wall molecules and they can be applied to the development of useful detectors of life. An extension of this work includes the visualization of microbial signatures by labeling LAL components with chromogenic or electron dense markers. The protein Limulus Anti-LPS Factor (LALF) has an extremely high affinity for LPS. By coupling LALF binding with colloidal gold labels we demonstrate a correlation of the structures visible by electron microscopy with biochemical evidence of microbial cell wall materials. Pure silica particles were mixed with cultures of E. coli (10(exp 6) cfu/mL). Samples were washed sequentially with buffered saline, LALF, antibody to LALF and finally colloidal gold-labeled Protein A. Negative controls were not exposed to E. coli but received identical treatment otherwise. Samples were coated with carbon and imaged on a JEOL JSM-840 scanning electron microscope with LaB6 source in the back scatter mode with the JEOL annular back scatter detector. 20 nm-scale black spots in this contrast-reversed image originate from electrons back-scattered by gold atoms. Negative controls did not give any signal. Future work will expand application of this technique to soil simulants and mineralized rock samples.

Quantifying chain reptation in entangled polymer melts: Topological and dynamical mapping of atomistic simulation results onto the tube model

NASA Astrophysics Data System (ADS)

Stephanou, Pavlos S.; Baig, Chunggi; Tsolou, Georgia; Mavrantzas, Vlasis G.; Kröger, Martin

2010-03-01

The topological state of entangled polymers has been analyzed recently in terms of primitive paths which allowed obtaining reliable predictions of the static (statistical) properties of the underlying entanglement network for a number of polymer melts. Through a systematic methodology that first maps atomistic molecular dynamics (MD) trajectories onto time trajectories of primitive chains and then documents primitive chain motion in terms of a curvilinear diffusion in a tubelike region around the coarse-grained chain contour, we are extending these static approaches here even further by computing the most fundamental function of the reptation theory, namely, the probability ψ(s,t) that a segment s of the primitive chain remains inside the initial tube after time t, accounting directly for contour length fluctuations and constraint release. The effective diameter of the tube is independently evaluated by observing tube constraints either on atomistic displacements or on the displacement of primitive chain segments orthogonal to the initial primitive path. Having computed the tube diameter, the tube itself around each primitive path is constructed by visiting each entanglement strand along the primitive path one after the other and approximating it by the space of a small cylinder having the same axis as the entanglement strand itself and a diameter equal to the estimated effective tube diameter. Reptation of the primitive chain longitudinally inside the effective constraining tube as well as local transverse fluctuations of the chain driven mainly from constraint release and regeneration mechanisms are evident in the simulation results; the latter causes parts of the chains to venture outside their average tube surface for certain periods of time. The computed ψ(s,t) curves account directly for both of these phenomena, as well as for contour length fluctuations, since all of them are automatically captured in the atomistic simulations. Linear viscoelastic properties such as the zero shear rate viscosity and the spectra of storage and loss moduli obtained on the basis of the obtained ψ(s,t) curves for three different polymer melts (polyethylene, cis-1,4-polybutadiene, and trans-1,4-polybutadiene) are consistent with experimental rheological data and in qualitative agreement with the double reptation and dual constraint models. The new methodology is general and can be routinely applied to analyze primitive path dynamics and chain reptation in atomistic trajectories (accumulated through long MD simulations) of other model polymers or polymeric systems (e.g., bidisperse, branched, grafted, etc.); it is thus believed to be particularly useful in the future in evaluating proposed tube models and developing more accurate theories for entangled systems.

Distributed Computation and TENEX-Related Activities

DTIC Science & Technology

1978-01-01

IPCF) which provides the inter-job communication functions required by MSG. MSG will be modified to use the IPCF primitives when running under TOPS...mmummi iiiwnrnrtnr’in i^WMBi. ■a^j.i.aiAj.k ■*"-’"’’"— •’ ’■■ BBN Report No. 3752 Bolt Beranek and Newman Inc. . . - . *. - primitive (e.g...from a process to MSG when a communication primitive is executed, and from MSG to a process when a pending event (e.g., outstanding receive operation

Primitive ideals of C q [ SL(3)

NASA Astrophysics Data System (ADS)

Hodges, Timothy J.; Levasseur, Thierry

1993-10-01

The primitive ideals of the Hopf algebra C q [ SL(3)] are classified. In particular it is shown that the orbits in Prim C q [ SL(3)] under the action of the representation group H ≅ C *× C * are parameterized naturally by W×W, where W is the associated Weyl group. It is shown that there is a natural one-to-one correspondence between primitive ideals of C q [ SL(3)] and symplectic leaves of the associated Poisson algebraic group SL(3, C).

A comment on methanogenic bacteria and the primitive ecology

NASA Technical Reports Server (NTRS)

Woese, C. R.

1977-01-01

As the phenotype of methanogenic bacteria is suggested to have been one of the major factors creating a dynamic balance between CO2 and CH4 in the primitive atmosphere, these organisms are thought to be very ancient. Their antiquity may be further postulated by comparative characterization of their ribosomal RNA. Accepting this antiquity, it is concluded that a carbon-dioxide-methane cycle, driven by photosynthesis, was the major carbon cycle in primitive ecology, and that photosynthesis and methanogens were thus contemporaneous.

Defibrotide in combination with granulocyte colony-stimulating factor significantly enhances the mobilization of primitive and committed peripheral blood progenitor cells in mice.

PubMed

Carlo-Stella, Carmelo; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Stucchi, Claudio; Cleris, Loredana; Formelli, Franca; Gianni, Massimo A

2002-11-01

Defibrotide is a polydeoxyribonucleotide, which significantly reduces the expression of adhesion molecules on endothelial cells. We investigated the activity of Defibrotide alone or in combination with recombinant human granulocyte colony-stimulating factor (rhG-CSF) to mobilize peripheral blood progenitor cells (PBPCs) in BALB/c mice. A 5-day treatment with Defibrotide alone (1-15 mg/mouse/day) had no effect on WBC counts, frequencies and absolute numbers of total circulating colony-forming cells (CFCs), i.e., granulocyte-macrophage colony-forming units, erythroid burst-forming units, and multilineage colony-forming units. As compared with mock-injected mice, administration of rhG-CSF alone (5 micro g/mouse/day) for 5 days significantly (P < or = 0.0001) increased WBC counts, CFC frequencies, and CFC absolute numbers by 2-, 13-, and 27-fold, respectively. As compared with control mice, the combined administration of Defibrotide (15 mg/mouse/day) and rhG-CSF significantly (P < or = 0.0001) increased WBC counts, frequencies and absolute numbers of CFCs by 4-, 38-, and 119-fold, respectively. As compared with rhG-CSF alone, administration of Defibrotide plus rhG-CSF resulted in a significant increase (P < or = 0.001) of the frequency of circulating long-term culture-initiating cells. In addition, transplantation of 2 x 10(5) rhG-CSF- or Defibrotide/rhG-CSF-mobilized mononuclear cells rescued 43% and 71% of recipient mice, respectively. Experiments of CFC homing performed in lethally irradiated or nonirradiated recipients showed that marrow homing of transplanted PBPCs was reduced by 3-fold in Defibrotide-treated animals as compared with mock-injected mice (P < or = 0.001), suggesting that the mobilizing effect of Defibrotide might be because of an effect on PBPC trafficking. In conclusion, our data demonstrate that Defibrotide synergizes with rhG-CSF and significantly increases the mobilization of a broad spectrum of PBPCs, including primitive and committed progenitor cells. These data might have relevant implications for autologous and allogeneic anticancer therapy in humans.

High grade primitive neuroectodermal tumor of the uterus: A case report.

PubMed

Dizon, A Mitch; Kilgore, Larry C; Grindstaff, Alan; Winkler, Marcus; Kimball, Kristopher J

2014-01-01

•Primitive neuroectodermal tumor of the uterus is extremely rare.•Diagnosis requires timely evaluation with molecular analysis.•Different combinations of adjuvant chemotherapy have been reported.

The origin and early evolution of life on Earth.

PubMed

Oró, J; Miller, S L; Lazcano, A

1990-01-01

We do not have a detailed knowledge of the processes that led to the appearance of life on Earth. In this review we bring together some of the most important results that have provided insights into the cosmic and primitive Earth environments, particularly those environments in which life is thought to have originated. To do so, we first discuss the evidence bearing on the antiquity of life on our planet and the prebiotic significance of organic compounds found in interstellar clouds and in primitive solar system bodies such as comets, dark asteroids, and carbonaceous chondrites. This is followed by a discussion on the environmental models of the Hadean and early Archean Earth, as well as on the prebiotic formation of organic monomers and polymers essential to life. We then consider the processes that may have led to the appearance in the Archean of the first cells, and how these processes may have affected the early steps of biological evolution. Finally, the significance of these results to the study of the distribution of life in the Universe is discussed.

Primary Ewing's sarcoma-primitive neuroectodermal tumor of the uterus: a case report and literature review.

PubMed

Park, Jeong-Yeol; Lee, Sun; Kang, Hyoung Jin; Kim, Hy-Sook; Park, Sang-Yoon

2007-08-01

Primary Ewing's sarcoma-primitive neuroectodermal tumor (ES-PNET) of the uterus is an extremely rare malignancy. A 30-year-old Korean woman presented with abnormal uterine bleeding with uterine enlargement. A computed tomography (CT) scan and magnetic resonance imaging (MRI) of the abdomen and pelvis showed a huge uterine mass measuring 18 x 20 x 21 cm, metastasis to both pelvic and para-aortic lymph nodes, and omental infiltration. The pathology report of the uterine mass described a uniformly hypercellular tumor, which was arranged in diffuse solid sheets of uniform, small, rounded, and sometimes spindle-shaped cells, with scanty cytoplasm. Immunohistochemically, the mass tested positive for vimentin, CD99, and chromogranin. The patient received several courses of combination chemotherapy and radiotherapy but died from tumor progression 16 months after the initial diagnosis. This is a rare case of primary uterine ES-PNET in a woman of reproductive age. A review of the literature indicates that primary uterine ES-PNET requires early diagnosis and multimodality treatment including surgery, chemotherapy, and radiotherapy. The behavior of this tumor is potentially aggressive.

A Hypothesis: Life Initiated from Two Genes, as Deduced from the RNA World Hypothesis and the Characteristics of Life-Like Systems

PubMed Central

Kawamura, Kunio

2016-01-01

RNA played a central role in the emergence of the first life-like system on primitive Earth since RNA molecules contain both genetic information and catalytic activity. However, there are several drawbacks regarding the RNA world hypothesis. Here, I briefly discuss the feasibility of the RNA world hypothesis to deduce the RNA functions that are essential for forming a life-like system. At the same time, I have conducted a conceptual analysis of the characteristics of biosystems as a useful approach to deduce a realistic life-like system in relation to the definition of life. For instance, an RNA-based life-like system should possess enough stability to resist environmental perturbations, by developing a cell-like compartment, for instance. Here, a conceptual viewpoint is summarized to provide a realistic life-like system that is compatible with the primitive Earth environment and the capabilities of RNA molecules. According to the empirical and conceptual analysis, I propose the hypothesis that the first life-like system could have initiated from only two genes. PMID:27490571

Peripheral nervous system neuroimmunology seen by a neuro-pathologist.

PubMed

Vallat, J-M

2014-10-01

In most dysimmune neuropathies, historically the microscopical lesions were described prior to immunological studies. The latter along with neuropathological studies have found some immune, albeit incomplete, explanations of the mechanisms of these lesions which we will describe in two main syndromes: the primitive auto-immune inflammatory peripheral polyneuropathies (GBS and CIDP) and polyneuropathies induced by a monoclonal dysglobulinemia. In some patients who have to be discussed case by case pathology (nerve biopsy) will confirm the diagnosis, may help to delineate the molecular anomalies and identify lesional mechanisms. We will review the high variability of nerve lesions which is characteristic of dysimmune neuropathies. Pathological studies confirm that both humoral and cellular immune reactions against Schwann cell and/or axonal antigens are implicated in primitive dysimmune neuropathies due to a dysfunction or failure of immune tolerance mechanisms. In case of a polyneuropathy associated to a monoclonal dysglobulinemia, pathological and immunological studies have shown that in many patients, the dysglobulinemia did harm the peripheral nerve; knowledge of the pathological lesions and their mechanisms is of major interest for orienting specific treatments. Copyright © 2014. Published by Elsevier Masson SAS.