Thymocyte apoptosis in response to low-dose radiation

International Nuclear Information System (INIS)

Shu-Zheng, Liu; Ying-Chun, Zhang; Ying, Mu; Xu, Su; Jian-Xiang, Liu

1996-01-01

Thymocyte apoptosis was assessed by counting apoptotic bodies with flow cytometry (FCM) and measuring DNA fragmentation with fluorescence spectrophotometry (FSP). J-shaped dose-response curves were obtained after both whole-body irradiation (WBI) of mice and in vitro irradiation of EL4 cells with doses ranging from 0.025 to 4 Gy X-rays. There was a significant reduction of apoptosis rate to below control level with doses within 0.2 Gy, and a dose-dependent increase in apoptosis with doses above 0.5 Gy. When thymocytes were cultured 24 h after WBI with 75 mGy X-rays in complete RPMI 1640 medium, a reduction in apoptosis was observed in the course of incubation for 72 h, and the presence of Con A in the medium accentuated this reduction in a dose- and time-dependent manner. The implications of these observations and the possible molecular mechanisms for future studies are proposed

The involvement of nuclear nucleases in rat thymocyte DNA degradation after γ-irradiation

International Nuclear Information System (INIS)

Nikonova, L.V.; Nelipovich, P.A.; Umansky, S.R.

1982-01-01

Possible mechanisms of internucleosomal DNA fragmentation in thymocytes of irradiated rats were studied. It was shown that thymocyte nuclei contain at least two nucleases that cleave DNA between nucleosomes - a Ca 2+ /Mg 2+ -dependent nuclease and an acidic one which does not depend on bivalent ions. 2 and 3 h after irradiation at a dose of 10 Gy the initial rate of DNA cleavage by Ca 2+ /Mg 2+ -dependent nuclease in isolated nuclei increased three and seven times, respectively, but the kinetics of DNA digestion by acidic nuclease did not change. The experiments with cycloheximide indicated that Ca 2+ /Mg 2+ -dependent endonuclease turns over at a high rate. The activity of the cytoplasmic acidic and Mg 2+ -dependent nucleases was shown to increase (by 40 and 50%, respectively) 3h after irradiation. The effect is caused by the de novo synthesis of the nucleases. At the same time the activity of nuclear nucleases did not essentially change. The chromatin isolated from rat thymocytes 3 h after irradiation did not differ in its sensitivity to some exogenic nucleases (DNAase I, micrococcal nuclease and nuclease from Serratia marcescens) from the control. Thus, Ca 2+ /Mg 2+ -dependent endonuclease seems to be responsible for the postirradiation internucleosomal DNA fragmentation in dying thymocytes. (Auth.)

Changes in plasma membrane structure upon irradiation on thymocytes

International Nuclear Information System (INIS)

Dreval', V.I.

1993-01-01

Thymocytes were irradiated with doses of 4 to 10 4 Gy. The binding of 1-anilinonaphtalene-8-sulphonate and Ca 2+ to plasma membranes; viscosity and lipid peroxidation; Stern-Folmer constant; and the number of Sh-groups of membrane proteins were determined. The structural changes in plasma membranes after irradiation of thymocytes were found to be cooperative

Compositional study of the Themis family

Science.gov (United States)

Marsset, Michael; Vernazza, Pierre; Birlan, Mirel; DeMeo, Francesca; Binzel, Richard P.; Dumas, Christophe; Milli, Julien; Popescu, Marcel

2015-11-01

Themis is an outer main-belt family comprising more than 4,000 dynamically well-established members (Nesvorny 2012), mainly B- and C-type asteroids (Florczak et al. 1999; Mothé-Diniz et al. 2005; Ziffer et al. 2011). This family is rather unique for a number of reasons:- It is believed to be the only main-belt family formed from the catastrophic disruption of a large (D>200 km) B-/C-type body (Brož et al. 2013). As such, it offers a unique view on the internal composition of a primitive asteroid.- Elst-Pizarro, one of the family member, was one of the first main belt comets to be discovered (Hsieh & Jewitt 2006).- 24 Themis is the first main belt asteroid for which water ice was detected at its surface (Campins et al. 2010; Rivkin & Emery 2010).- The low density values recorded for two family members (<1.3 g/cm3 , Descamps et al. 2007; Marchis et al. 2008) likely imply high fractions of ice(s) in the interior of these bodies.The last three features all point towards an ice-rich composition for the Themis parent body while showing little compatibility with a thermally metamorphosed body that has been heated throughout at temperatures exceeding 300 K. The latter interpretation was previously suggested on the basis of a similarity between the near-infrared spectral properties of heated CI/CM chondrites and those of the family members’ surfaces (Clark et al. 2010; Ziffer et al. 2011). In brief, the Themis family members appear unsampled by our meteorite collections. Recently, Vernazza et al. (2015) instead proposed that Interplanetary Dust Particles (IDPs) may be more appropriate extraterrestrial analogs for these objects’ surfaces.In the light of Vernazza et al. (2015)’s recent work, we investigated the surface mineralogy of a sample of Themis family members using a combined dataset of spectra covering the visible (Bus & Binzel 2002; Lazzaro et al. 2004), near-infrared (this work), and mid-infrared (Licandro et al. 2012; Hargrove et al. 2015) spectral ranges

Thymic lymphocytes. III. Cooperative phenomenon in the proliferation of thymocytes under Con A stimulation.

Science.gov (United States)

Papiernik, M; Jacobson, J B

1986-01-01

In the present paper, the response of thymocytes to Con A is analyzed in terms of a cooperative phenomenon between medullary thymocytes, cortical thymocytes, thymic accessory cells, and interleukin 2. Medullary thymocytes respond spontaneously to Con A and produce IL-2. The addition of exogenously produced IL-2 enhances their proliferation. Small numbers of cortical (PNA+) thymocytes do not respond to Con A, even in the presence of IL-2-containing supernatant. By increasing the number of PNA+ cells per well, sensitivity to Con A and IL-2 appears. This response may be linked either to the increase in a minor PNA+-responding population and/or to the enhanced contamination by medullary thymocytes and macrophages in non-responding PNA+ thymocyte population. In this hypothesis, either the contaminating cells respond by themselves and/or cooperate with PNA+ cells to induce their proliferation. Coculture of non-responding low numbers of PNA+ thymocytes with Con A- and IL-2-containing supernatant in the presence of PNA- cells containing thymic medullary thymocytes and macrophages always produces a higher response than that of each individual population. These results show that a cooperative phenomenon occurs in the cocultures of PNA+ and PNA- thymic cells. We can show using PNA+ and PNA- thymocytes with different Thy 1 alleles, that indeed both PNA+ and populations participate PNA-thymocytes with different Thy 1 alleles, that indeed both PNA+ and PNA- populations participate in the generation of proliferating cells. We can demonstrate, by lysis experiments with monoclonal antibodies and complement that at the end of coculture, most of the proliferating cells are Lyt 1+, and part are Lyt 2+ or L3T4+. We discuss the fact that the phenotype of the cells after activation does not allow us to deduce the phenotype of their precursors. Lysis of Ia+ cells prior to coculture, reduces the level of the proliferative response but does not modify the percentage of cooperation produced

Restoration of adenosine deaminase-deficient human thymocyte development in vitro by inhibition of deoxynucleoside kinases.

Science.gov (United States)

Joachims, Michelle L; Marble, Patrick A; Laurent, Aletha B; Pastuszko, Peter; Paliotta, Marco; Blackburn, Michael R; Thompson, Linda F

2008-12-01

Mutations in the gene encoding adenosine deaminase (ADA), a purine salvage enzyme, lead to immunodeficiency in humans. Although ADA deficiency has been analyzed in cell culture and murine models, information is lacking concerning its impact on the development of human thymocytes. We have used chimeric human/mouse fetal thymic organ culture to study ADA-deficient human thymocyte development in an "in vivo-like" environment where toxic metabolites accumulate in situ. Inhibition of ADA during human thymocyte development resulted in a severe reduction in cellular expansion as well as impaired differentiation, largely affecting mature thymocyte populations. Thymocyte differentiation was not blocked at a discrete stage; rather, the paucity of mature thymocytes was due to the induction of apoptosis as evidenced by activation of caspases and was accompanied by the accumulation of intracellular dATP. Inhibition of adenosine kinase and deoxycytidine kinase prevented the accumulation of dATP and restored thymocyte differentiation and proliferation. Our work reveals that multiple deoxynucleoside kinases are involved in the phosphorylation of deoxyadenosine when ADA is absent, and suggests an alternate therapeutic strategy for treatment of ADA-deficient patients.

SCL, LMO1 and Notch1 Reprogram Thymocytes into Self-Renewing Cells

Science.gov (United States)

Rojas-Sutterlin, Shanti; Herblot, Sabine; Hébert, Josée; Sauvageau, Guy; Lemieux, Sébastien; Lécuyer, Eric; Veiga, Diogo F. T.; Hoang, Trang

2014-01-01

The molecular determinants that render specific populations of normal cells susceptible to oncogenic reprogramming into self-renewing cancer stem cells are poorly understood. Here, we exploit T-cell acute lymphoblastic leukemia (T-ALL) as a model to define the critical initiating events in this disease. First, thymocytes that are reprogrammed by the SCL and LMO1 oncogenic transcription factors into self-renewing pre-leukemic stem cells (pre-LSCs) remain non-malignant, as evidenced by their capacities to generate functional T cells. Second, we provide strong genetic evidence that SCL directly interacts with LMO1 to activate the transcription of a self-renewal program coordinated by LYL1. Moreover, LYL1 can substitute for SCL to reprogram thymocytes in concert with LMO1. In contrast, inhibition of E2A was not sufficient to substitute for SCL, indicating that thymocyte reprogramming requires transcription activation by SCL-LMO1. Third, only a specific subset of normal thymic cells, known as DN3 thymocytes, is susceptible to reprogramming. This is because physiological NOTCH1 signals are highest in DN3 cells compared to other thymocyte subsets. Consistent with this, overexpression of a ligand-independent hyperactive NOTCH1 allele in all immature thymocytes is sufficient to sensitize them to SCL-LMO1, thereby increasing the pool of self-renewing cells. Surprisingly, hyperactive NOTCH1 cannot reprogram thymocytes on its own, despite the fact that NOTCH1 is activated by gain of function mutations in more than 55% of T-ALL cases. Rather, elevating NOTCH1 triggers a parallel pathway involving Hes1 and Myc that dramatically enhances the activity of SCL-LMO1 We conclude that the acquisition of self-renewal and the genesis of pre-LSCs from thymocytes with a finite lifespan represent a critical first event in T-ALL. Finally, LYL1 and LMO1 or LMO2 are co-expressed in most human T-ALL samples, except the cortical T subtype. We therefore anticipate that the self-renewal network

The DNA damage- and transcription-associated protein Paxip1 controls thymocyte development and emigration

DEFF Research Database (Denmark)

Callen, E.; Faryabi, R.B.; Daniel, Jeremy Austin

2012-01-01

Histone 3 lysine 4 trimethylation (H3K4me3) is associated with promoters of active genes and found at hot spots for DNA recombination. Here we have shown that PAXIP1 (also known as PTIP), a protein associated with MLL3 and MLL4 methyltransferase and the DNA damage response, regulates RAG......-mediated cleavage and repair during V(D)J recombination in CD4 CD8 DP thymocytes. Loss of PAXIP1 in developing thymocytes diminished Jα H3K4me3 and germline transcription, suppressed double strand break formation at 3' Jα segments, but resulted in accumulation of unresolved T cell receptor α-chain gene (Tcra......) breaks. Moreover, PAXIP1 was essential for release of mature single positive (SP) αβ T cells from the thymus through transcriptional activation of sphingosine-1-phosphate receptor S1pr1 as well as for natural killer T cell development. Thus, in addition to maintaining genome integrity during Tcra...

Growth hormone in the presence of laminin modulates interaction of human thymic epithelial cells and thymocytes in vitro

Directory of Open Access Journals (Sweden)

Marvin Paulo Lins

Full Text Available BACKGROUND: Several evidences indicate that hormones and neuropeptides function as immunomodulators. Among these, growth hormone (GH is known to act on the thymic microenvironment, supporting its role in thymocyte differentiation. The aim of this study was to evaluate the effect of GH on human thymocytes and thymic epithelial cells (TEC in the presence of laminin. RESULTS: GH increased thymocyte adhesion on BSA-coated and further on laminin-coated surfaces. The number of migrating cells in laminin-coated membrane was higher in GH-treated thymocyte group. In both results, VLA-6 expression on thymocytes was constant. Also, treatment with GH enhanced laminin production by TEC after 24 h in culture. However, VLA-6 integrin expression on TEC remained unchanged. Finally, TEC/thymocyte co-culture model demonstrated that GH elevated absolute number of double-negative (CD4-CD8- and single-positive CD4+ and CD8+ thymocytes. A decrease in cell number was noted in double-positive (CD4+CD8+ thymocytes. CONCLUSIONS: The results of this study demonstrate that GH is capable of enhancing the migratory capacity of human thymocytes in the presence of laminin and promotes modulation of thymocyte subsets after co-culture with TEC.

Kinetic analysis of thymocyte attachment to thymus stromal cells in culture by using phase-contrast and scanning electron microscopy

International Nuclear Information System (INIS)

LaRochelle, G.G.; Jones, K.H.

1989-01-01

Direct cellular contact between thymocytes and thymus stromal cells within the thymus appears to contribute to the maturation of thymocytes. Thymocyte-stromal cell complexes, formed in vivo, have been isolated by others and postulated to play a role in T-cell differentiation. These previous studies have been hampered, however, by a time-consuming isolation procedure from which only small numbers of these complexes are recovered. We have examined a model to study thymocyte-stromal cell complexes in vitro in which thymocytes are added to primary cultures of thymus stromal cells. In the present study, we found that thymocytes were histotypically selective in their attachment to thymus stromal cells. We also investigated the kinetics of thymocyte attachment to these thymus stromal cells. Cultures were examined at selected time intervals from 5 min through 3 days of incubation. Thymocyte attachment to stromal cells was a biphasic interaction, with maximum surface attachment at 15 min of cocultivation, followed by migration of thymocytes into the cultures. Morphological studies were confirmed by using 3 H-leucine-labeled thymocytes and liquid scintigraphy. With increased time in culture, thymocytes became amoeboid and migrated between the layers of stromal cells where thymocyte mitotic figures were seen at 4 and 8 hr. In some cases it appeared that stromal cells, which often grew two to three cell layers deep, played an active role in enclosing thymocytes within the cultures. Large numbers of viable thymocytes were observed in the cultures at 24 hr. The number of thymocytes then decreased progressively on days 2 and 3, when relatively few were found within the layers of the culture

Solving for the Surface: An Automated Approach to THEMIS Atmospheric Correction

Science.gov (United States)

Ryan, A. J.; Salvatore, M. R.; Smith, R.; Edwards, C. S.; Christensen, P. R.

2013-12-01

Here we present the initial results of an automated atmospheric correction algorithm for the Thermal Emission Imaging System (THEMIS) instrument, whereby high spectral resolution Thermal Emission Spectrometer (TES) data are queried to generate numerous atmospheric opacity values for each THEMIS infrared image. While the pioneering methods of Bandfield et al. [2004] also used TES spectra to atmospherically correct THEMIS data, the algorithm presented here is a significant improvement because of the reduced dependency on user-defined inputs for individual images. Additionally, this technique is particularly useful for correcting THEMIS images that have captured a range of atmospheric conditions and/or surface elevations, issues that have been difficult to correct for using previous techniques. Thermal infrared observations of the Martian surface can be used to determine the spatial distribution and relative abundance of many common rock-forming minerals. This information is essential to understanding the planet's geologic and climatic history. However, the Martian atmosphere also has absorptions in the thermal infrared which complicate the interpretation of infrared measurements obtained from orbit. TES has sufficient spectral resolution (143 bands at 10 cm-1 sampling) to linearly unmix and remove atmospheric spectral end-members from the acquired spectra. THEMIS has the benefit of higher spatial resolution (~100 m/pixel vs. 3x5 km/TES-pixel) but has lower spectral resolution (8 surface sensitive spectral bands). As such, it is not possible to isolate the surface component by unmixing the atmospheric contribution from the THEMIS spectra, as is done with TES. Bandfield et al. [2004] developed a technique using atmospherically corrected TES spectra as tie-points for constant radiance offset correction and surface emissivity retrieval. This technique is the primary method used to correct THEMIS but is highly susceptible to inconsistent results if great care in the

Effects of low dose radiation on differentiation, activation and apoptosis of thymocytes in mice

International Nuclear Information System (INIS)

Su Xu; Zhang Yingchun; Wan Hong; Liu Shuzheng

1997-01-01

Objective: To elucidate the possible mechanism of immunoenhancement after low dose radiation (LDR), the differentiation, activation and apoptosis of thymocytes following low dose irradiation were studied. Method: Kunming mice were whole-body irradiated (WBI) with low dose X-rays. The expressions of CD4, CD8, TCR, CD3, IL-2R, (Ca 2+ ) i , Bcl-2 Bax and apoptosis of thymocytes were analyzed by flow cytometry. Results: It was found that the ratio of T H /T S showed no significant changes after LDR. Thymocyte apoptosis was not increased after LDR. The increase of Bcl-2/Bax ratio after LDR might be one of its mechanisms. LDR could expedites the process of differentiation of, and facilitate the signal transduction in, thymocytes. Conclusion: The results indicate that the mechanism of immunoenhancement might be related to the expedition of the maturation, differentiation and activation of thymocytes, thus up-regulating the capability of supplying more mature T lymphocytes to the periphery by the thymus after LDR

Tissue breathing and topology of rats thymocytes surface under acute total γ-irradiation.

Science.gov (United States)

Nikitina, I A; Gritsuk, A I

2017-12-01

Assessment of the effect of single total γ irradiation to the parameters of mitochondrial oxidation and the topology of the thymocyte surface. The study was performed in sexually mature white outbreeding male rats divided into three groups: two experimental and one control. The states of energy metabolism were determined by the rate of oxygen consumption by the thymus tissues on endogenous substrates at the presence of 2,4 dinitrophenol, uncoupler of a tissue breathing (TB) and oxidative phosphorylation (OP) after a single total γ irradiation at a dose of 1.0 Gy at 3, 10, 40 and 60 days. The topology of thymus cells was assessed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). On the 3rd and 10th days after total gamma irradiation at a dose of 1.0 Gy, a significant decrease in respira tory activity was determined in thymus tissues on endogenous substrates. Simultaneously, on the 3rd day, pro nounced changes in the morphological parameters of thymocytes (height, volume, area of contact with the sub strate) and the topology of their surface were also observed. On the 10th day after irradiation, most of the morpho logical parameters of thymocytes, except for their volume, were characterized by restoration to normal. In the long term (on the 30th and 60th days after exposure), a gradual but not complete recovery of the respiratory activity of thymocytes was observed, accompanied by an increase in the degree of dissociation of TD and OP. The obtained data reflect and refine mechanisms of post radiation repair of lymphopoiesis, showing the presence of conjugated changes in the parameters of aerobic energy metabolism of thymocytes, morphology and topology of their surface. The synchronism of changes in the parameters under study is a reflection of the state of the cytoskeleton, the functional activity of which largely depends on the level and efficiency of mitochondrial oxidation. І. A. Nikitina, A. I. Gritsuk.

Constitutive expression of tert in thymocytes leads to increased incidence and dissemination of T-cell lymphoma in Lck-Tert mice.

Science.gov (United States)

Canela, Andrés; Martín-Caballero, Juan; Flores, Juana M; Blasco, María A

2004-05-01

Here we describe a new mouse model with constitutive expression of the catalytic subunit of telomerase (Tert) targeted to thymocytes and peripheral T cells (Lck-Tert mice). Two independent Lck-Tert mouse lines showed higher incidences of spontaneous T-cell lymphoma than the corresponding age-matched wild-type controls, indicating that constitutive expression of Tert promotes lymphoma. Interestingly, T-cell lymphomas in Lck-Tert mice were more disseminated than those in wild-type controls and affected both lymphoid and nonlymphoid tissues, while nonlymphoid tissues were never affected with lymphoma in age-matched wild-type controls. Importantly, these roles of Tert constitutive expression in promoting tumor progression and dissemination were independent of the role of telomerase in telomere length maintenance, since telomere length distributions on a single-cell basis were identical in Lck-Tert and wild-type thymocytes. Finally, Tert constitutive expression did not interfere with telomere capping in Lck-Tert primary thymocytes, although it resulted in greater chromosomal instability upon gamma irradiation in Lck-Tert primary lymphocytes than in controls, suggesting that Tert overexpression may interfere with the cellular response to DNA damage.

Mechanism of chromatin degradation in thymocytes of irradiated rats

International Nuclear Information System (INIS)

Zotova, R.N.; Umanskij, S.R.; Tokarskaya, V.I.

1983-01-01

A biphase change in poly (ADP-ribose) polymerase activity of the thymocyte chromatin was observed after 10 Gy irradiation of rats: during the first minutes the incorporation of 14 C-NAD increased by 40% then started decreasing to make 110, 60 and 35% after 1, 2 and 3 h, respectively. Irradiation of rat thymus chromatin in vitro sharply decreased poly (ADP-ribose) polymerase activity. The possible role of changes in the poly (ADP-ribose) synthesis in the activation of nuclear Ca/Mg-dependent endonuclease and in the postirradiation degradation of the thymocyte chromatin is discussed

In vitro evidence for participation of DEC-205 expressed by thymic cortical epithelial cells in clearance of apoptotic thymocytes.

NARCIS (Netherlands)

Small, M; Kraal, G.

2003-01-01

Binding of apoptotic cells was compared after incubation of thymocytes with two clones of murine thymic stromal cells to which CD4(+)/CD8(+) thymocytes attach. With the BA/10, but not the BA/2, clone, thymocytes with apoptotic morphology were bound irreversibly. These tightly bound thymocytes were

First results from the Blackstone HF radar in support of THEMIS

Science.gov (United States)

Lester, M.; Ruohoniemi, J. M.; Baker, J. B.; Barnes, R. J.; Clauer, C. R.; Greenwald, R. A.; Grocott, A.; Milan, S. E.; Yeoman, T. K.

2008-12-01

A new HF radar has been constructed and built in Blackstone, VA, as part of the SuperDARN/StormDARN programme specifically with the purpose of providing coverage over the Canadian ground sector in THEMIS. The new radar began operations in February 2008, an optimum time to support the first THEMIS tail campaign. This paper will discuss the importance of having radars at lower latitudes than the auroral zone locations of SuperDARN for substorm studies. Furthermore, the paper will also present the first results from this radar together with other SuperDARN observations during the THEMIS tail period.

Cytotoxicity of Environmentally Relevant Concentrations of Aluminum in Murine Thymocytes and Lymphocytes

Directory of Open Access Journals (Sweden)

Jamal Kamalov

2011-01-01

Full Text Available The effects of low concentrations of aluminum chloride on thymocytes and lymphocytes acutely dissociated from young mice were studied using flow cytometry with a DNA-binding dye. We demonstrate a rapid and dose-dependent injury in murine thymocytes and lymphocytes resulting from exposure to aluminum, as indicated by an increase in the entry into the cell of the DNA-binding dye, propidium iodine. A 60-minute exposure to 10 μM AlCl3 caused damage of about 5% of thymocytes, while 50% were injured after 10 minutes at 20 μM. Nearly all thymocytes showed evidence of damage at 30 μM AlCl3 after only 5 minutes of incubation. In lymphocytes, injury was observed at 15 μM AlCl3 and less than 50% of cells were injured after a 60-minute exposure to 20 μM. Injury only rarely proceeded to rapid cell death and was associated with cell swelling. These results suggest that aluminum has cytotoxic effects on cells of the immune system.

Thymocyte apoptosis induced by p53-dependent and independent pathways

International Nuclear Information System (INIS)

Clarke, A.R.; Purdie, C.A.; Harrison, D.J.; Morris, R.G.; Bird, C.C.; Hooper, M.L.; Wyllie, A.H.

1993-01-01

The authors studied the dependence of apoptosis on p53 expression in cells from the thymus cortex. Short-term thymocyte cultures were prepared from mice constitutively heterozygous or homozygous for a deletion in the p53 gene introduced into the germ line after gene targeting. Wild-type thymocytes readily undergo apoptosis after treatment with ionizing radiation, the glucocorticoid methylprednisolone, or etoposide (an inhibitor of topoisomerase II), or after Ca 2+ -dependent activation by phorbol ester and a calcium ionophore. In contrast, homozygous null p53 thymocytes are resistant to induction of apoptosis by radiation or etoposide, but retain normal sensitivity to glucocorticoid and calcium. The time-dependent apoptosis that occurs in untreated cultures is unaffected by p53 status. Cells heterozygous for p53 deletion are partially resistant to radiation and etoposide. Results show that p53 exerts a significant and dose-dependent effect in the initiation of apoptosis, but only when it is induced by agents that cause DNA-strand breakage. (Author)

Early Results from the Odyssey THEMIS Investigation

Science.gov (United States)

Christensen, Philip R.; Bandfield, Joshua L.; Bell, James F., III; Hamilton, Victoria E.; Ivanov, Anton; Jakosky, Bruce M.; Kieffer, Hugh H.; Lane, Melissa D.; Malin, Michael C.; McConnochie, Timothy

2003-01-01

The Thermal Emission Imaging System (THEMIS) began studying the surface and atmosphere of Mars in February, 2002 using thermal infrared (IR) multi-spectral imaging between 6.5 and 15 m, and visible/near-IR images from 450 to 850 nm. The infrared observations continue a long series of spacecraft observations of Mars, including the Mariner 6/7 Infrared Spectrometer, the Mariner 9 Infrared Interferometer Spectrometer (IRIS), the Viking Infrared Thermal Mapper (IRTM) investigations, the Phobos Termoscan, and the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES). The THEMIS investigation's specific objectives are to: (1) determine the mineralogy of localized deposits associated with hydrothermal or sub-aqueous environments, and to identify future landing sites likely to represent these environments; (2) search for thermal anomalies associated with active sub-surface hydrothermal systems; (3) study small-scale geologic processes and landing site characteristics using morphologic and thermophysical properties; (4) investigate polar cap processes at all seasons; and (5) provide a high spatial resolution link to the global hyperspectral mineral mapping from the TES investigation. THEMIS provides substantially higher spatial resolution IR multi-spectral images to complement TES hyperspectral (143-band) global mapping, and regional visible imaging at scales intermediate between the Viking and MGS cameras.

THEMIS Images as Art #4

Science.gov (United States)

2004-01-01

Released 5 February 2004Humanity is a very visual species. We rely on our eyes to tell us what is going on in the world around us. Put any image in front of a person and that person will examine the picture looking for anything familiar. Even if the examiner has no idea what he/she is looking at in a picture, he/she will still be able to make a statement about the picture, usually preceded by the words 'it looks like...' The image above is part of the surface of Mars, but is presented for its artistic value rather than its scientific value. When first viewed, this image solicited a statement that 'it looks like...' something seen in everyday life.Despite being named for the Roman god of war, Mars also can have a delicate side, as shown by this area that looks like lace.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

THEMIS Images as Art #5

Science.gov (United States)

2004-01-01

Released 6 February 2004Humanity is a very visual species. We rely on our eyes to tell us what is going on in the world around us. Put any image in front of a person and that person will examine the picture looking for anything familiar. Even if the examiner has no idea what he/she is looking at in a picture, he/she will still be able to make a statement about the picture, usually preceded by the words 'it looks like...' The image above is part of the surface of Mars, but is presented for its artistic value rather than its scientific value. When first viewed, this image solicited a statement that 'it looks like...' something seen in everyday life.This crater ejecta looks quite a bit like a blast, as would be seen in comic books or perhaps on an old episode of Batman.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

CD28 in thymocyte development and peripheral T cell activation in mice exposed to suspended particulate matter

International Nuclear Information System (INIS)

Drela, Nadzieja; Zesko, Izabela; Jakubowska, Martyna; Biernacka, Marzena

2006-01-01

The CD28:B7 signaling pathway is very important for the activity of mature peripheral T lymphocytes and thymocyte development. The proper development of thymocytes into mature single positive CD4 + and CD8 + T cells is crucial for almost all immune functions. In naturally occurring conditions, T cells maturation in the thymus is influenced by environmental agents. The expression of CD28 and the distribution of CD28 low/high thymocytes have been examined at various stages of thymocyte development in BALB/c mice exposed to air-suspended particulate matter (ASM). Acute exposure to ASM resulted in the decrease of CD28 expression in the total thymocyte population. The increase of the percentage of CD28 low and the decrease of CD28 high thymocytes were observed, which may account for the acceleration of thymocyte development under the conditions of elevated risk resulting from the exposure of animals to environmental xenobiotics. ASM exposure resulted in the increase of the level of proliferation of lymph node T cells induced by anti-CD3 and anti-CD28 monoclonal antibodies activation despite normal expression of CD28 molecule. In contrast, the level of proliferation of spleen T cells was lowered or normal dependently of the concentration of stimuli used for activation. Results of these studies demonstrate that acute exposure of mice to ASM can result in the progression of two contrasting processes in the immune system: upregulation of thymocyte development, which contributes to the maintenance of peripheral T cell pool, and over-activation of lymph node lymphocytes, which may lead to uncontrolled immunostimulation

Stimulation of respiration in rat thymocytes induced by ionizing radiation

International Nuclear Information System (INIS)

Gudz, T.I.; Pandelova, I.G.; Novgorodov, S.A.

1994-01-01

The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O 2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La 3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation. 43 refs., 2 figs., 3 tabs

Cell surface appearance of unexpected host MHC determinants on thymocytes from radiation bone marrow chimeras

International Nuclear Information System (INIS)

Sharrow, S.O.; Mathieson, B.J.; Singer, A.

1981-01-01

The phenotypic appearance of cell surface antigens on murine thymocytes from long-term radiation bone marrow chimeras was analyzed using indirect immunofluorescence and flow microfluorometry. Cells maturing in the thymi of these mice were typed for MHC (Kk, I-Ak, H-2b, Kb, and Ib) and non-MHC (Lty 1, Ly 9, and TL) determinants. All cells were of donor origin as determined by non-MHC (Ly) phenotype in P1 leads to P2, P1 x P2 leads to P1, and P1 leads to P2 radiation chimeras. In contrast, the MHC phenotypes of these thymocytes were markedly affected by the host environment. Specifically, H-2 and I-A determinants of both parental phenotypes were detected on thymocytes from P1 leads to P1 x P2 chimeras; I-A determinants of host phenotype were present, whereas I-A determinants of donor phenotype were reduced on thymocytes from P1 x P2 leads to P1 chimeras; and thymocytes from P1 leads to P2 chimeras possessed H-2 and I-A determinants of host phenotype but showed reduction of donor I-A phenotype determinants. The appearance of host cell surface H-2 and I-A determinants on thymocytes from chimeras closely parallels the functional recognition of MHC determinants by T cells from chimeric mice and thus may be significantly related to the development of the self-recognition repertoire by maturing T cells

Biphasic stimulation of cellular calcium concentration by 3,5,3'-triiodothyronine in rat thymocytes

International Nuclear Information System (INIS)

Segal, J.

1988-01-01

3,5,3'-Triiodothyronine (T 3 ) produced a rapid and transient increase in 45 Ca uptake and cytoplasmic free calcium concentration in rat thymocytes, which is the most rapid effect of T 3 in this system. This effect was manifested in cells suspended in medium containing 1 mM calcium. The T 3 effect on 45 Ca uptake was evident at 15-30 s, reached maximum at 30-60 s, and returned to control values at 5 min. The T 3 effect on cytoplasmic free calcium concentration was seen after 30 s, reached maximum at 7 min, and returned to control values after 24 min. In cells suspended in Ca 2+ -free medium, T 3 produced a similar rapid increase in 45 Ca uptake, which was sustained for at least 60 min, but T 3 failed to change cytoplasmic free calcium concentration. Alprenolol (10 μM) blocked the stimulatory effects of T 3 on these two functions in a similar fashion. From these results, the authors suggest that in rat thymocytes T 3 influences cellular calcium economy through a biphasic mechanism in which T 3 first increases calcium uptake which, in turn, if followed by a release of calcium from intracellular pool(s), resulting in a further increase in cytoplasmic free calcium concentration and the activation of Ca 2+ -regulated systems. Moreover, the present study provides further support for the postulate that in the rat thymocyte calcium serves as the first messenger for the plasma membrane-mediated stimulatory effects of T 3 on several metabolic functions

Dose-effect relationship of apoptosis induced by fission-neutron in murine thymocytes

International Nuclear Information System (INIS)

Yuan Bin; Li Liang; Xue Wencheng; Sun Jianmin; Wang Baoqin

2000-01-01

Objective: To investigate the effectiveness of high LET fission-neutron to induce apoptosis in murine thymocytes and to compare it with that of low LET 60 Co γ-ray. Methods: Apoptosis induction was studied qualitatively by light and transmission electron microscopy and DNA gel electrophoresis,also quantitatively by flow cytometry(FCM) and diphenylamine (DPA)methods. Results: DNA ladders of murine thymocytes were detectable, the typical apoptosis of thymocytes could be observed morphologically by means of light and electron microscopy at 6 h after fission-neutron irradiation with doses ranging from 0.5 to 5.0 Gy, meanwhile the percentages of apoptosis increased with increasing doses. After exposure to γ-rays with doses ranging from 1.0 to 30 Gy, the experimental results were similar to those from neutron radiation. The incidence of apoptosis peaked at about 20 Gy, the percentages did not increase further when doses increased. Conclusion: Apoptosis of murine thymocytes can be induced when mice are exposed to either fission-neutron (0.5-5.0 Gy) or to γ-ray (1-30 Gy). Although the relationship between apoptosis and radiation doses is similar, the percentage of apoptosis induced by neutron irradiation is higher than that induced by γ-irradiation. The RBE values of fission-neutron for inducing apoptosis murine thymocytes are 2.09 (by FCM method) and 2.37 (by DPA method), respectively. These results also suggest that fission-neutron-induced murine immune tissue is more severe than that induced by γ-rays at several hours post-irradiation and this might be the basis for heavy damage to immune tissues induced by fission-neutron-irradiation in later period

Role of Akt/PKB and PFKFB isoenzymes in the control of glycolysis, cell proliferation and protein synthesis in mitogen-stimulated thymocytes.

Science.gov (United States)

Houddane, Amina; Bultot, Laurent; Novellasdemunt, Laura; Johanns, Manuel; Gueuning, Marie-Agnès; Vertommen, Didier; Coulie, Pierre G; Bartrons, Ramon; Hue, Louis; Rider, Mark H

2017-06-01

Proliferating cells depend on glycolysis mainly to supply precursors for macromolecular synthesis. Fructose 2,6-bisphosphate (Fru-2,6-P 2 ) is the most potent positive allosteric effector of 6-phosphofructo-1-kinase (PFK-1), and hence of glycolysis. Mitogen stimulation of rat thymocytes with concanavalin A (ConA) led to time-dependent increases in lactate accumulation (6-fold), Fru-2,6-P 2 content (4-fold), 6-phosphofructo-2-kinase (PFK-2)/fructose-2,6-bisphosphatase isoenzyme 3 and 4 (PFKFB3 and PFKFB4) protein levels (~2-fold and ~15-fold, respectively) and rates of cell proliferation (~40-fold) and protein synthesis (10-fold) after 68h of incubation compared with resting cells. After 54h of ConA stimulation, PFKFB3 mRNA levels were 45-fold higher than those of PFKFB4 mRNA. Although PFKFB3 could be phosphorylated at Ser461 by protein kinase B (PKB) in vitro leading to PFK-2 activation, PFKFB3 Ser461 phosphorylation was barely detectable in resting cells and only increased slightly in ConA-stimulated cells. On the other hand, PFKFB3 and PFKFB4 mRNA levels were decreased (90% and 70%, respectively) by exposure of ConA-stimulated cells to low doses of PKB inhibitor (MK-2206), suggesting control of expression of the two PFKFB isoenzymes by PKB. Incubation of thymocytes with ConA resulted in increased expression and phosphorylation of the translation factors eukaryotic initiation factor-4E-binding protein-1 (4E-BP1) and ribosomal protein S6 (rpS6). Treatment of ConA-stimulated thymocytes with PFK-2 inhibitor (3PO) or MK-2206 led to significant decreases in Fru-2,6-P 2 content, medium lactate accumulation and rates of cell proliferation and protein synthesis. These data were confirmed by using siRNA knockdown of PFKFB3, PFKFB4 and PKB α/β in the more easily transfectable Jurkat E6-1 cell line. The findings suggest that increased PFKFB3 and PFKFB4 expression, but not increased PFKFB3 Ser461 phosphorylation, plays a role in increasing glycolysis in mitogen

β-endorphin modulation of mitogen-stimulated calcium uptake by rat thymocytes

International Nuclear Information System (INIS)

Hemmick, L.M.; Bidlack, J.M.

1987-01-01

Lymphocytes stimulated by mitogens or antigens exhibit an enhanced calcium uptake early in the proliferation or activation response. Modulation of this calcium uptake results in alterations of proliferation and immunocompetence. β-endorphin and other opioids affect several parameters of lymphocyte competence. Limited data are available concerning the mechanism(s) of these effects. This study examines whether a possible opioid mechanism is the modification of the early calcium influx into stimulated lymphocytes. The time course of both concanavalin A (Con A) and phytohemagglutinin (PHA)-stimulated 45 Ca 2+ uptake into thymocytes was characterized to determine the optimal time for testing the effects of opioids. Β-Endorphin 1-31 significantly enhanced Con A-stimulated 45 Ca 2+ uptake into rat thymocytes. This peptide had no significant effect on PHA-simulated 45 Ca 2+ uptake or on basal thymocyte 45 Ca 2+ flux. The β/sub h/-endorphin stimulatory effect was titratable in the range of 0.1 nM to 10 μM. Naloxone did not reverse the enhancement. Met-enkephalinamide and other opioid agonists did not duplicate the stimulatory effect. Thus, the β/sub h/-endorphin 1-31 enhancement of Con A-stimulated 45 Ca 2+ uptake by rat thymocytes does not operate via classical opioid receptor mechanisms. β/sub h/-endorphin 1-31 appears to be acting on a subset of T cells that are responsive to Con A but not to PHA. 30 references, 4 figures, 1 table

Post-irradiation thymocyte regeneration after bone marrow transplantation

International Nuclear Information System (INIS)

Boersma, W.J.A.

1981-01-01

Bone marrow cells were separated according to buoyant density, velocity sedimentation and cell surface charge. Fractionated (C3H x AKR)F 1 bone marrow cells were transplanted into lethally-irradiated C3H recipients. In all fractions, the CFUs content and the capacity to restore the thymus cell population were determined. For all the physical parameters tested, thymocyte progenitor cells show the same distribution as CFUs. The relationship between number of thymocyte progenitor cells and number of CFUs is dependent on density. Bone marrow progenitors of PHA responsive cells are of low buoyant density and show a distribution which resembles the distribution of the progenitors of Thy 1 positive cells. After transplantation of large numbers of bone marrow cells into irradiated mice, no significant change in the CFUs content of the thymus was observed. (author)

TNF-α is involved in the abnormal thymocyte migration during experimental Trypanosoma cruzi infection and favors the export of immature cells.

Directory of Open Access Journals (Sweden)

Ana Rosa Pérez

Full Text Available Previous studies revealed a significant production of inflammatory cytokines together with severe thymic atrophy and thymocyte migratory disturbances during experimental Chagas disease. Migratory activity of thymocytes and mature T cells seem to be finely tuned by cytokines, chemokines and extracellular matrix (ECM components. Systemic TNF-α is enhanced during infection and appears to be crucial in the response against the parasite. However, it also seems to be involved in disease pathology, since it is implicated in the arrival of T cells to effector sites, including the myocardium. Herein, we analyzed the role of TNF-α in the migratory activity of thymocytes in Trypanosoma cruzi (T. cruzi acutely-infected mice. We found increased expression and deposition of TNF-α in the thymus of infected animals compared to controls, accompanied by increased co-localization of fibronectin, a cell migration-related ECM molecule, whose contents in the thymus of infected mice is also augmented. In-vivo studies showed an enhanced export of thymocytes in T. cruzi-infected mice, as ascertained by intrathymic injection of FITC alone or in combination with TNF-α. The increase of immature CD4(+CD8(+ T cells in secondary lymphoid organs was even more clear-cut when TNF-α was co-injected with FITC. Ex-vivo transmigration assays also revealed higher number of migrating cells when TNF-α was added onto fibronectin lattices, with higher input of all thymocyte subsets, including immature CD4(+CD8(+. Infected animals also exhibit enhanced levels of expression of both mRNA TNF-α receptors in the CD4(+CD8(+ subpopulation. Our findings suggest that in T. cruzi acute infection, when TNF-α is complexed with fibronectin, it favours the altered migration of thymocytes, promoting the release of mature and immature T cells to different compartments of the immune system. Conceptually, this work reinforces the notion that thymocyte migration is a multivectorial biological event

Anti-thymocyte serum as part of an immunosuppressive regimen in treating haematological immune-mediated diseases in dogs.

Science.gov (United States)

Cuq, B; Blois, S L; Mathews, K A

2017-06-01

To report the outcomes associated with the use of rabbit anti-dog thymocyte serum in dogs with haematological immune-mediated diseases. Medical records from 2000 to 2016 of patients diagnosed with immune-mediated haemolytic anaemia, immune-mediated thrombocytopenia, pancytopenia and myelofibrosis were reviewed. All dogs had a severe or refractory disease and received rabbit anti-dog thymocyte serum. Lymphocyte counts were used to monitor the immediate anti-thymocyte effect of therapy; long-term patient outcome was recorded. A total of 10 dogs were included. All dogs except one had a notable decrease in their lymphocyte count after rabbit anti-dog thymocyte serum; four of nine had a decrease to less than 10% of the initial lymphocyte count and one dog reached 10·8%. All dogs were discharged from the hospital following their treatment. The dog with no alteration of lymphocyte count following therapy with rabbit anti-dog thymocyte serum had refractory immune mediated haemolytic anemia and was euthanised within two weeks. All other cases achieved clinical remission with immunosuppressive therapy eventually being tapered (3 of 10) or discontinued (6 of 10). Rabbit anti-dog thymocyte serum therapy might be of interest as an adjunctive therapy in refractory immune-mediated diseases and suppressed lymphocyte counts in most dogs. © 2017 British Small Animal Veterinary Association.

Inhibition of erythroid cell growth by allogeneic murine lymphocytes. Evidence for a synergism between lymph node cells and thymocytes

International Nuclear Information System (INIS)

Blomgren, H.; Jacobsson, H.

1974-01-01

Murine lymphoid cells from thymus and lymph nodes were tested for synergistic response in a graft-vs-host test. The test is based on the principle that allogeneic lymphocytes inhibit erythroid cell proliferation in the spleens of irradiated mice infused with syngeneic bone marrow cells. Mixtures of thymocytes and lymph node cells from the same parental strain yielded graft-vs-host responses in irradiated F 1 -hybrids higher than expected by summing the responses of the two cell populations tested separately. A similar synergistic response was obtained using mixtures of thymocytes and lymph node cells obtained from the two parental strains of the hybrid, whereas such an effect was not detected using mixtures of lymph node cells or mixtures of thymocytes from the two parental strains. Nor could synergy be demonstrated between parental strain lymph node cells and thymocytes syngeneic with the bone marrow target cells. Thymocytes obtained from one parental strain which was injected into its irradiated F 1 -hybrid transformed into a population of sensitized cells in the spleens of the recipients. This transformation was suppressed by the simultaneous injection of lymph node cells from the second parental strain. Since there is a synergistic immune response by such cell mixtures it is concluded that thymocytes may enhance the graft-vs-host response of lymph node cells. Parental strain thymocytes and lymph node cells, the latter being specifically immunologically tolerant to the bone marrow target cells, failed to give a synergistic response indicating that thymocytes do not transform unresponsive lymphocytes into responsive, but rather enhance the reactivity of existing, specifically responsive cells. The results thus show that thymocytes may enhance the response of lymph node cells in this specific graft-vs-host assay

Effect of syngeneic thymocytes on proliferation of the small intestinal epithelium in mice

International Nuclear Information System (INIS)

Shmakov, A.N.; Aparovich, G.G.; Trufakin, V.A.

1986-01-01

This paper describes the study of the action of syngeneic thymocytes on proliferation of the epithelium of the mouse small intestine. The mice were injected with 3 H-thymidine in the experiments. Under the experimental conditions presented here, syngeneic thymocytes can reduce the number of DNA-synthesizing cells in the intestinal epithelium, causing narrowing of the zone of proliferation and enlargement of the zone of differentiation of the enterocytes

beta. -endorphin modulation of mitogen-stimulated calcium uptake by rat thymocytes

Energy Technology Data Exchange (ETDEWEB)

Hemmick, L.M.; Bidlack, J.M.

1987-10-19

Lymphocytes stimulated by mitogens or antigens exhibit an enhanced calcium uptake early in the proliferation or activation response. Modulation of this calcium uptake results in alterations of proliferation and immunocompetence. ..beta..-endorphin and other opioids affect several parameters of lymphocyte competence. Limited data are available concerning the mechanism(s) of these effects. This study examines whether a possible opioid mechanism is the modification of the early calcium influx into stimulated lymphocytes. The time course of both concanavalin A (Con A) and phytohemagglutinin (PHA)-stimulated /sup 45/Ca/sup 2 +/ uptake into thymocytes was characterized to determine the optimal time for testing the effects of opioids. BETA-Endorphin 1-31 significantly enhanced Con A-stimulated /sup 45/Ca/sup 2 +/ uptake into rat thymocytes. This peptide had no significant effect on PHA-simulated /sup 45/Ca/sup 2 +/ uptake or on basal thymocyte /sup 45/Ca/sup 2 +/ flux. The ..beta../sub h/-endorphin stimulatory effect was titratable in the range of 0.1 nM to 10 ..mu..M. Naloxone did not reverse the enhancement. Met-enkephalinamide and other opioid agonists did not duplicate the stimulatory effect. Thus, the ..beta../sub h/-endorphin 1-31 enhancement of Con A-stimulated /sup 45/Ca/sup 2 +/ uptake by rat thymocytes does not operate via classical opioid receptor mechanisms. ..beta../sub h/-endorphin 1-31 appears to be acting on a subset of T cells that are responsive to Con A but not to PHA. 30 references, 4 figures, 1 table.

Prelude to THEMIS tail conjunction study

Directory of Open Access Journals (Sweden)

A. T. Y. Lui

2007-05-01

Full Text Available A close conjunction of several satellites (LANL, GOES, Polar, Geotail, and Cluster distributed from the geostationary altitude to about 16 R_E downstream in the tail occurred during substorm activity as indicated by global auroral imaging and ground-based magnetometer data. This constellation of satellites resembles what is planned for the THEMIS (Time History of Events and Macroscopic Interactions during Substorms mission to resolve the substorm controversy on the location of the substorm expansion onset region. In this article, we show in detail the dipolarization and dynamic changes seen by these satellites associated with two onsets of substorm intensification activity. In particular, we find that dipolarization at ~16 R_E downstream in the tail can occur with dawnward electric field and without plasma flow, just like some near-Earth dipolarization events reported previously. The spreading of substorm disturbances in the tail coupled with complementary ground observations indicates that the observed time sequence on the onsets of substorm disturbances favors initiation in the near-Earth region for this THEMIS-like conjunction.

Activation of chromatin degradation by a protein factor of thymocyte cytoplasm of irradiated mice

International Nuclear Information System (INIS)

Soldatenkov, V.A.; Filippovich, I.V.

1986-01-01

A cytoplasmic thymocyte fraction isolated 1 h after irradiation of mice accelerates chromatin degradation in isolated nuclei. Treatment of the cytoplasmic fraction by heat and injection of cycloheximide to mice prevent the acceleration of DNA degradation. The analysis of the chromatin degradation products and the kinetics of this process at acid and alkaline pH shows that activation of DNA degradation in thymocytes by a factor obtained from the irradiated cell cytoplasm is specific for a Ca 2+ , Mg 2+ -dependent enzyme. The time- and dose-dependent parameters of the appearance in the thymocyte cytoplasm of the factor influencing degradation of chromatin are in a good agreement with both the time of the onset of its postirradiation degradation and the dose dependence of this process

Radiosensitivity of human lymphocytes and thymocytes

International Nuclear Information System (INIS)

Kwan, D.K.; Norman, A.

1977-01-01

The in vitro survival of human peripheral blood lymphocytes and thymocytes was measured 4 days following graded doses of γ radiation. Results indicate considerable heterogeneity among lymphocyte subpopulations with respect to radiosensitivity. Total T lymphocytes were characterized by rosette formation with neuraminidase-treated sheep red blood cells (nSRBC); early T (T/sub E/) cells, by early rosettes; and B cells, by their inability to form nSRBC rosettes. Late T (T/sub L/) cells were defined as T -- T/sub E/. Survival curves of T, T/sub E/, and B cells are biphasic. The radiosensitive and radioresistant components of T, T/sub E/, and B cells all have a D 0 of about 50 and 550 rad, respectively. B cells appeared to be slightly more radiosensitive than T cells. T/sub L/ cells and thymocytes, however, appeared to be homogeneous with respect to radiosensitivity, both having D 0 values of about 135 rad. The survival of T cells in mixed T and B cell cultures resembled that of separated T cells, suggesting that ionizing radiation has no significant effect on rosette formation. It also indicates that interactions of T and B cells do not significantly affect their radiation responses

THEMIS Observations of Domes and Associated Lineaments in Arcadia Planitia

Science.gov (United States)

Milam, K. A.; McSween, H. Y.

2003-12-01

The northern plains of Mars contain several high concentrations (Acidalia, Utopia, Elysium, etc.) of small (System (THEMIS), visible images from THEMIS and the Mars Orbiter Camera, and elevation data from the Mars Orbiter Laser Altimeter were used to study a 390,000 km 2 area ˜1500 km to the northwest of Elysium Mons. Of interest is a region centered on Tyndall crater and bordered by Phlegras Montes to the west. The area is characterized by gentle, westward-sloping plains, with noticeable slope breaks along several N-S trending wrinkle ridges. Several hundred circular domes dot this area. Domes display features consistent with a volcanic origin. Most are circular to slightly elliptical at their base, with basal diameters ranging from 0.5-6 km. Summits typically rise material (as compared to the coarser-grained summits). Less than 25% of domes appear to have summit depressions and ~ 1% show fractured summit areas. Some domes appear to be randomly distributed, but many are aligned in chains according to wrinkle ridge orientations. Using THEMIS data, we have detected over 165 domes that are aligned with and superimposed upon over 145 lineaments. Most lineaments are cut by lineaments. No laterally extensive flows have been detected as emanating from lineaments, nor have similar lineaments been detected immediately outside the study area. The association of domes and lineaments is consistent with observations of volcanic constructs along open fissures in many terrestrial volcanic fields. Assuming a volcanic origin, the dome-lineament relationship suggests localized, structurally-controlled eruptions along open fissures. Initial extension caused the opening of fractures, which was followed by localized extrusions. Such localized development can provide information about eruption rates, magma compositions, or the physical properties of erupted lava. Either during or after volcanic activity, continued extension led to several domes being dissected by fissures.

Factors influencing the vaccinia-specific cytotoxic response of thymocytes from normal and chimeric mice

International Nuclear Information System (INIS)

Doherty, P.C.; Schwartz, D.H.; Bennink, J.R.; Korngold, R.

1981-01-01

Following adoptive transfer into irradiated recipients, thymocytes can be induced to respond strongly to vaccinia virus. High levels of cytotoxic T-lymphocyte (CTL) activity may be generated from thymus, but not from spleen, of 3-day-old mice. The capacity of thymocytes to differentiate into effector CTL tends to be lost with age. Some of this loss may reflect positive suppression: a single, low dose of cyclophosphamide allows the reemergence of responsiveness in at least one mouse strain. Thymocytes from [A leads to (A x B)F1] and [(A x B)F1 leads to A] chimeras show the response patterns that would by predicted from previous studies of lymph node and spleen cells. However, thymic function seems to be rapidly lost in the [A leads to (A x B)F1] Chimeras

Apoptosis in thymocytes and lymphoma cells induced by neutrons and X-rays

International Nuclear Information System (INIS)

Ohyama, Harumi; Koike, Sachiko; Ando, Kouichi

1993-01-01

Apoptosis is a distinctive mode of programmed cell death with characteristic morphological and biochemical features. The cells undergoing apoptosis display shrinkage, chromatin condensation and internucleosomal breakage of DNA. The cell death is a process through which organisms get rid of unwanted cells. Thymocytes are highly radiosensitive, and undergo typical apoptosis within a few hours after the exposure to X-ray. Also extremely radiosensitive thymic lymphoma cells have been found. The effect of 30 MeV NIRS fast neutrons on the induction of apoptosis in thymocytes and thymoma cells was examined in comparison with that of X-ray. Although apoptotic cells increased gradually with time, the apoptotic process proceeded rapidly in individual cells after the onset. By the measurement of cell size distribution, the appearance of a distinct apoptotic cell peak was observed. In the case of neutron irradiation on SCA1 thymic lymphoma cells, the method for counting apoptotic cells based on chromatin condensation was developed. The cell volume reduction of thymocytes, the dose survival curves and the induction of apoptosis in SCA1 are reported. (K.I.)

Transgenic expression of microRNA-181d augments the stress-sensitivity of CD4(+CD8(+ thymocytes.

Directory of Open Access Journals (Sweden)

Serkan Belkaya

Full Text Available Physiological stress resulting from infections, trauma, surgery, alcoholism, malnutrition, and/or pregnancy results in a substantial depletion of immature CD4(+CD8(+ thymocytes. We previously identified 18 distinct stress-responsive microRNAs (miRs in the thymus upon systemic stress induced by lipopolysaccharide (LPS or the synthetic glucocorticoid, dexamethasone (Dex. MiRs are short, non-coding RNAs that play critical roles in the immune system by targeting diverse mRNAs, suggesting that their modulation in the thymus in response to stress could impact thymopoiesis. MiR-181d is one such stress-responsive miR, exhibiting a 15-fold down-regulation in expression. We utilized both transgenic and gene-targeting approaches to study the impact of miR-181d on thymopoiesis under normal and stress conditions. The over-expression of miR-181d in developing thymocytes reduced the total number of immature CD4(+CD8(+ thymocytes. LPS or Dex injections caused a 4-fold greater loss of these cells when compared with the wild type controls. A knockout mouse was developed to selectively eliminate miR-181d, leaving the closely spaced and contiguous family member miR-181c intact. The targeted elimination of just miR-181d resulted in a thymus stress-responsiveness similar to wild-type mice. These experiments suggest that one or more of three other miR-181 family members have overlapping or compensatory functions. Gene expression comparisons of thymocytes from the wild type versus transgenic mice indicated that miR-181d targets a number of stress, metabolic, and signaling pathways. These findings demonstrate that selected miRs enhance stress-mediated thymic involution in vivo.

Sequential appearance of thymocyte subpopulations and T cell antigen receptor gene messages in the mouse thymus after sublethal irradiation

International Nuclear Information System (INIS)

Tomooka, S.; Matsuzaki, G.; Kishihara, K.; Tanaka, K.; Yoshikai, Y.; Taniguchi, K.; Himeno, K.; Nomoto, K.

1987-01-01

The sequential differentiation patterns of thymocyte were observed with cell surface phenotypes and the expression of T cell antigen receptor in 800 rad irradiated adult mice. Thymus was severely reduced in size and cell number by day 5 after whole body irradiation and rapidly recovered from day 7 to day 14. Surface marker analysis on day 5 after irradiation showed thymocytes with Thy-1low L3T4+/Lyt-2- dominantly existed and suggested that these cells were radioresistant-survived cells. On the other hand, thymocytes on day 7 were composed of a large number of Thy-1high L3T4+/Lyt-2+ blast-like cells and a relatively high proportion of Thy-1high L3T4-/Lyt-2- cells which expressed a large amount of gamma-chain gene messages but scarcely any alpha- and beta-chain gene messages similar to the fetal thymocytes. On day 14, thymocytes were composed mostly of Thy-1high H-2low L3T4+/Lyt-2+ subpopulation which expressed a remarkably low level of gamma-chain gene messages, and high levels of alpha- and beta-chain transcripts analogous to those of normal adult thymus. Taken together, intrathymic radioresistent stem cells for T thymocytes seem to proliferate and differentiate after irradiation with the same pattern as was seen in a fetal thymus development

Indirect presentation in the thymus limits naive and regulatory T-cell differentiation by promoting deletion of self-reactive thymocytes.

Science.gov (United States)

Yap, Jin Yan; Wirasinha, Rushika C; Chan, Anna; Howard, Debbie R; Goodnow, Christopher C; Daley, Stephen R

2018-02-07

Acquisition of T-cell central tolerance involves distinct pathways of self-antigen presentation to thymocytes. One pathway termed indirect presentation requires a self-antigen transfer step from thymic epithelial cells (TECs) to bone marrow-derived cells before the self-antigen is presented to thymocytes. The role of indirect presentation in central tolerance is context-dependent, potentially due to variation in self-antigen expression, processing and presentation in the thymus. Here, we report experiments in mice in which TECs expressed a membrane-bound transgenic self-antigen, hen egg lysozyme (HEL), from either the insulin (insHEL) or thyroglobulin (thyroHEL) promoter. Intrathymic HEL expression was less abundant and more confined to the medulla in insHEL mice compared with thyroHEL mice. When indirect presentation was impaired by generating mice lacking MHC class II expression in bone marrow-derived antigen-presenting cells, insHEL-mediated thymocyte deletion was abolished, whereas thyroHEL-mediated deletion occurred at a later stage of thymocyte development and Foxp3 + regulatory T-cell differentiation increased. Indirect presentation increased the strength of T-cell receptor signalling that both self-antigens induced in thymocytes, as assessed by Helios expression. Hence, indirect presentation limits the differentiation of naive and regulatory T cells by promoting deletion of self-reactive thymocytes. © 2018 John Wiley & Sons Ltd.

Project THEMIS: A Center for Remote Sensing.

Science.gov (United States)

This report summarizes the technical work accomplished under Project THEMIS, A Center for Remote Sensing at the University of Kansas during the...period 16 September 1967 through 15 September 1973. The highlights of the four major areas forming the remote sensing system are presented. A detailed description of the latest radar spectrometer results is presented.

Protective effects of melatonin on damage of thymocytes in mice induced by ionizing radiation

International Nuclear Information System (INIS)

Zhang Xuan; Wang Zhenqi; Liu Yang; Gong Shouliang; Zhang Ming; Liu Shuzheng

2004-01-01

Objective: To explore the effects of melatonin (MLT) on the damage of mouse thymocytes in vivo induced by ionizing radiation and its mechanism. Methods: The exogenous MLT was given to Kunming mice to establish the animal models of single and successive administration of MLT through intraperitoneal injection before whole-body irradiation with 1 Gy X-rays. For single administration of MLT, the apoptotic body percentage (ABP) and DNA lytic rate (DLR) in the thymocytes were determined with flow cytometry and fluorospectrophotometry, respectively, 12 h after irradiation. For successive administration of MLT, 3 H-TdR incorporative rate (HTIR ) was determined 24 h after irradiation. Results: The number of thymocytes in single administration group was significantly lower than that in the sham-irradiation group 12 h after irradiation with 1 Gy X-rays (P -1 MLT group was significantly higher, while the ABP and DLR were significantly lower than those in 0 mg·kg -1 MLT group (simple irradiation, P -1 MLT were significantly higher than that in 0 mg·kg -1 MLT group (P -1 MLT group was also significantly higher (P<0.05). Conclusion: The administration of exogenous MLT before irradiation can decrease the damage of mouse thymocytes induced by ionizing radiation, and has the protective effect on immune functions in mice. (authors)

Early dominance of irradiated host cells in the responder profiles of thymocytes from P → F1 radiation chimeras

International Nuclear Information System (INIS)

Korngold, R.; Bennink, J.R.; Doherty, P.C.

1981-01-01

The number of cells in the thymus of radiation (1000 rad) chimeras increases approximately 10-fold between 7 and 14 days after reconstitution with bone marrow. At least 50% of the cells in thymus on day 14 are of host origin and respond to virus presented in the context of both H-2/sup k/ and H-2/sup b/ when primed in irradiated, virus-infected (b x k)F 1 recipients. Strong CTL responses can be generated from thymocytes of donor origin on day 21. All evidence of a significant host thymocyte component has disappeared by day 28. The responsiveness of 14-day thymocytes is not abrogated by pretreatment of the mice used to make the chimeras with anti-thymocyte serum or by using doses of irradiation as high as 1200 rads to eliminate host components

Growth of single T cells and single thymocytes in a high cloning efficiency filler-cell free microculture system.

Science.gov (United States)

Chen, W F; Ewing, T; Scollay, R; Shortman, K

1988-01-01

A high cloning-efficiency microculture system is described in which single T cells, stimulated to divide by phorbol ester and calcium ionophore, grow rapidly under the influence of purified growth factors in the absence of other cells. The kinetics of clonal growth has been monitored over a five day period by phase-contrast microscopy. Mature peripheral T cells, and mature subpopulations from the thymus, responded with a cloning efficiency over 80%; they required IL-2 as a minimum but several other factors enhanced growth. Ly2+L3T4- thymocytes (mean doubling time 10.4 hr) grew more rapidly than Ly2-L3T4+ thymocytes (mean doubling time 15.2 hr). Early (Ly2-L3T4-) thymocytes responded with a cloning efficiency of 60%; their efficient growth was dependent on both IL-1 and IL-2. The typical Ly2+L3T4+ cortical thymocyte did not grow under these conditions.

MILREM extends THeMIS mission set / Huw Williams

Index Scriptorium Estoniae

Williams, Huw

2016-01-01

Eesti kaitsetehnika ettevõte MILREM OÜ täiendab oma relvasüsteemi THeMIS ja teeb selleks koostööd mitmete firmadega. Tulevikus soovitakse lisaks Eesti kaitseväele teha koostööd ka Läti kaitseväega ja kasutada sõjatehnikat sealsetel õppustel

The conveyor belt hypothesis for thymocyte migration: participation of adhesion and de-adhesion molecules.

Science.gov (United States)

Villa-Verde, D M; Calado, T C; Ocampo, J S; Silva-Monteiro, E; Savino, W

1999-05-01

Thymocyte differentiation is the process by which bone marrow-derived precursors enter the thymus, proliferate, rearrange the genes and express the corresponding T cell receptors, and undergo positive and/or negative selection, ultimately yielding mature T cells that will represent the so-called T cell repertoire. This process occurs in the context of cell migration, whose cellular and molecular basis is still poorly understood. Kinetic studies favor the idea that these cells leave the organ in an ordered pattern, as if they were moving on a conveyor belt. We have recently proposed that extracellular matrix glycoproteins, such as fibronectin, laminin and type IV collagen, among others, produced by non-lymphoid cells both in the cortex and in the medulla, would constitute a macromolecular arrangement allowing differentiating thymocytes to migrate. Here we discuss the participation of both molecules with adhesive and de-adhesive properties in the intrathymic T cell migration. Functional experiments demonstrated that galectin-3, a soluble beta-galactoside-binding lectin secreted by thymic microenvironmental cells, is a likely candidate for de-adhesion proteins by decreasing thymocyte interaction with the thymic microenvironment.

Alterations in Mesenteric Lymph Node T Cell Phenotype and Cytokine Secretion are Associated with Changes in Thymocyte Phenotype after LP-BM5 Retrovirus Infection

Directory of Open Access Journals (Sweden)

Maria C. Lopez

2005-01-01

Full Text Available In this study, mouse MLN cells and thymocytes from advanced stages of LP-BM5 retrovirus infection were studied. A decrease in the percentage of IL-7+ cells and an increase in the percentage of IL-16+ cells in the MLN indicated that secretion of these cytokines was also altered after LP-BM5 infection. The percentage of MLN T cells expressing IL-7 receptors was significantly reduced, while the percentage of MLN T cells expressing TNFR-p75 and of B cells expressing TNFR-p55 increased. Simultaneous analysis of surface markers and cytokine secretion was done in an attempt to understand whether the deregulation of IFN-Υ secretion could be ascribed to a defined cell phenotype, concluding that all T cell subsets studied increased IFN-Υ secretion after retrovirus infection. Finally, thymocyte phenotype was further analyzed trying to correlate changes in thymocyte phenotype with MLN cell phenotype. The results indicated that the increase in single positive either CD4+CD8- or CD4- CD8+ cells was due to accumulation of both immature (CD3- and mature (CD3+ single positive thymocytes. Moreover, single positive mature thymocytes presented a phenotype similar to the phenotype previously seen on MLN T cells. In summary, we can conclude that LP-BM5 uses the immune system to reach the thymus where it interferes with the generation of functionally mature T cells, favoring the development of T cells with an abnormal phenotype. These new T cells are activated to secrete several cytokines that in turn will favor retrovirus replication and inhibit any attempt of the immune system to control infection.

Magnetometer Data in the Classroom as a part of the NASA THEMIS Satellite Mission

Science.gov (United States)

Peticolas, L. M.; Bean, J.; Walker, A.

2011-12-01

The NASA-funded THEMIS mission was designed to determine the onset time and location of magnetic substorms of Earth's space environment, a prerequisite to understanding space weather. THEMIS is an acronym for Time History of Events and Macroscale Interactions during Substorms. he Geomagnetic Event Observation Network by Students (GEONS) project was the flagship, formal education component of the E/PO program. With the placement of magnetometers in the proximity of rural schools throughout the country, middle and high school teachers along with their students benefited from the opportunity to work with 'real-time' data and participated in hands-on space science activities. Particular attention was paid to placing the magnetometer stations at schools in rural communities whose students were traditionally underserved and underrepresented in the sciences. The project offered to the teachers of these students long-term professional development opportunities that centered around THEMIS-related space science and the magnetometer data. The THEMIS E/PO final evaluation report for the main phase of the THEMIS mission covered the period from 2003-2009, describing the impact of this program such as this program placed magnetometers sites at 13 rural, underserved schools/communities, two-fifths of which are on tribal lands; and provided intensive professional development for 20 teachers from 2004 through 2009. A core group of eight teachers estimated reaching more than 2,720 students with THEMIS-related materials/ideas. 75% of these students are minorities in science. Core teachers provided evidence of the project's positive impact on students' attitudes toward science and their choices for courses that position them for STEM-related careers. Core teachers reported sharing THEMIS-related materials/ideas with 275 colleagues. The NewsHour with Jim Lehrer featured the Petersburg, Alaska site potentially reaching more than 5 million viewers in two airings, according to Nielsen

Early double-negative thymocyte export in Trypanosoma cruzi infection is restricted by sphingosine receptors and associated with human chagas disease.

Directory of Open Access Journals (Sweden)

Ailin Lepletier

2014-10-01

Full Text Available The protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironmental and lymphoid compartments. Acute infection results in severe atrophy of the organ and early release of immature thymocytes into the periphery. To date, the pathophysiological effects of thymic changes promoted by parasite-inducing premature release of thymocytes to the periphery has remained elusive. Herein, we show that sphingosine-1-phosphate (S1P, a potent mediator of T cell chemotaxis, plays a role in the exit of immature double-negative thymocytes in experimental Chagas disease. In thymuses from T. cruzi-infected mice we detected reduced transcription of the S1P kinase 1 and 2 genes related to S1P biosynthesis, together with increased transcription of the SGPL1 sphingosine-1-lyase gene, whose product inactivates S1P. These changes were associated with reduced intrathymic levels of S1P kinase activity. Interestingly, double-negative thymocytes from infected animals expressed high levels of the S1P receptor during infection, and migrated to lower levels of S1P. Moreover, during T. cruzi infection, this thymocyte subset expresses high levels of IL-17 and TNF-α cytokines upon polyclonal stimulation. In vivo treatment with the S1P receptor antagonist FTY720 resulted in recovery the numbers of double-negative thymocytes in infected thymuses to physiological levels. Finally, we showed increased numbers of double-negative T cells in the peripheral blood in severe cardiac forms of human Chagas disease.

Possible nature and specificity of a protein factor favoringsolubilization of chromatin from irradiated animal thymocytes

International Nuclear Information System (INIS)

Soldatenkov, V.A.; Trebenok, Z.A.; Filippovich, I.V.

1989-01-01

It is shown that activation of endonucleolysis of thymocyte nuclear chromatin by protein factor from the cells of irradiated animals is not conditioned by its nuclease activity or ability to activate Ca 2+ , Mg 2+ - dependent lymphocyte endonuclease. DNA degradation character and kinetics of accumulation of the forming products doesn't change in autolysis of thymocyte nucleus. It is assumed that protein factor doesn't participate in starting mechanisms of postirradiation chromatin degradation but can be of significance at delayed stages of the process. The discovered effect is characterized by tissue and specific characteristic

Recombinatorial biases and convergent recombination determine interindividual TCRβ sharing in murine thymocytes.

Science.gov (United States)

Li, Hanjie; Ye, Congting; Ji, Guoli; Wu, Xiaohui; Xiang, Zhe; Li, Yuanyue; Cao, Yonghao; Liu, Xiaolong; Douek, Daniel C; Price, David A; Han, Jiahuai

2012-09-01

Overlap of TCR repertoires among individuals provides the molecular basis for public T cell responses. By deep-sequencing the TCRβ repertoires of CD4+CD8+ thymocytes from three individual mice, we observed that a substantial degree of TCRβ overlap, comprising ∼10-15% of all unique amino acid sequences and ∼5-10% of all unique nucleotide sequences across any two individuals, is already present at this early stage of T cell development. The majority of TCRβ sharing between individual thymocyte repertoires could be attributed to the process of convergent recombination, with additional contributions likely arising from recombinatorial biases; the role of selection during intrathymic development was negligible. These results indicate that the process of TCR gene recombination is the major determinant of clonotype sharing between individuals.

The conveyor belt hypothesis for thymocyte migration: participation of adhesion and de-adhesion molecules

Directory of Open Access Journals (Sweden)

Villa-Verde D.M.S.

1999-01-01

Full Text Available Thymocyte differentiation is the process by which bone marrow-derived precursors enter the thymus, proliferate, rearrange the genes and express the corresponding T cell receptors, and undergo positive and/or negative selection, ultimately yielding mature T cells that will represent the so-called T cell repertoire. This process occurs in the context of cell migration, whose cellular and molecular basis is still poorly understood. Kinetic studies favor the idea that these cells leave the organ in an ordered pattern, as if they were moving on a conveyor belt. We have recently proposed that extracellular matrix glycoproteins, such as fibronectin, laminin and type IV collagen, among others, produced by non-lymphoid cells both in the cortex and in the medulla, would constitute a macromolecular arrangement allowing differentiating thymocytes to migrate. Here we discuss the participation of both molecules with adhesive and de-adhesive properties in the intrathymic T cell migration. Functional experiments demonstrated that galectin-3, a soluble ß-galactoside-binding lectin secreted by thymic microenvironmental cells, is a likely candidate for de-adhesion proteins by decreasing thymocyte interaction with the thymic microenvironment.

Changes in thymocytes due to local irradiation of a portion of the maxilla in mice. A study of NKT cells and γδT cells

International Nuclear Information System (INIS)

Satho, Taigo; Tamasawa, Ken; Yosue, Takashi; Arai, Thiaki

2000-01-01

We have been investigating the changes of lymphocyte subsets in immune organs after head and neck irradiation. The aim of the present study was to determine the influence of local irradiation (10 Gy) of a portion of the maxilla on the thymocyte subsets, specifically NKT cells and γδT cells in mice. The thymocyte subsets were analyzed following irradiation using a fluorometer (anti-CD4, CD8, TCRαβ, TCRγδ and NK1.1 monoclonal antibodies) and the outcome compared with that obtained from no-irradiation groups. The following results were obtained: The total number of thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of DN (double negative; CD4 - CD8 - ), CD4 + SP (CD4 + single positive; CD4 + CD8 - ) and CD8 + SP (CD8 + single positive; CD4 - CD8 + ) thymocytes showed a significant decrease one day after irradiation. The absolute number of DP (double positive; CD4 + CD8 + ) thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of NKT and γδT cells showed a significant decrease one day after irradiation. In conclusion, the results suggest that NKT cells and γδT cells exhibit behavior which is the same as main stream thymocytes, except DP thymocytes. (author)

Changes in thymocytes due to local irradiation of a portion of the maxilla in mice. A study of NKT cells and {gamma}{delta}T cells

Energy Technology Data Exchange (ETDEWEB)

Satho, Taigo; Tamasawa, Ken; Yosue, Takashi [Nippon Dental Univ., Tokyo (Japan); Arai, Thiaki

2000-07-01

We have been investigating the changes of lymphocyte subsets in immune organs after head and neck irradiation. The aim of the present study was to determine the influence of local irradiation (10 Gy) of a portion of the maxilla on the thymocyte subsets, specifically NKT cells and {gamma}{delta}T cells in mice. The thymocyte subsets were analyzed following irradiation using a fluorometer (anti-CD4, CD8, TCR{alpha}{beta}, TCR{gamma}{delta} and NK1.1 monoclonal antibodies) and the outcome compared with that obtained from no-irradiation groups. The following results were obtained: The total number of thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of DN (double negative; CD4{sup -} CD8{sup -}), CD4{sup +} SP (CD4{sup +} single positive; CD4{sup +} CD8{sup -}) and CD8{sup +} SP (CD8{sup +} single positive; CD4{sup -} CD8{sup +}) thymocytes showed a significant decrease one day after irradiation. The absolute number of DP (double positive; CD4{sup +} CD8{sup +}) thymocytes showed a significant decrease one day and three days after irradiation. The absolute number of NKT and {gamma}{delta}T cells showed a significant decrease one day after irradiation. In conclusion, the results suggest that NKT cells and {gamma}{delta}T cells exhibit behavior which is the same as main stream thymocytes, except DP thymocytes. (author)

Structural chromatin organization as a factor determining the rate of chromatin endonucleolysis in irradiated and intact thymocytes

International Nuclear Information System (INIS)

Ryabchenko, N.I.; Ivannik, B.P.

1987-01-01

A study was made of chromatin endonucleolysis in hypotonized thymocytes incubating in digestive buffers containing different concentrations of potassium, magnesium, calcium, and mercaptoethanol. Inhibition of endonucleolysis by univalent cation during the first 20 min of incubation was followed by intensive chromatin degradation. A decrease in free potassium content retarded chromatin degradation and enhanced the inhibiting effect of the univalent cations. The regularities of changes in the rate of chromatin endonucleolysis in different digestive buffers were similar with both exposed and intact thymocytes

Prenatal cadmium exposure dysregulates sonic hedgehog and Wnt/β-catenin signaling in the thymus resulting in altered thymocyte development

International Nuclear Information System (INIS)

Hanson, Miranda L.; Brundage, Kathleen M.; Schafer, Rosana; Tou, Janet C.; Barnett, John B.

2010-01-01

Cadmium (Cd) is both an environmental pollutant and a component of cigarette smoke. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports in the literature of immunomodulatory effects of prenatal exposure to Cd. The sonic hedgehog (Shh) and Wnt/β-catenin pathways are required for thymocyte maturation. Several studies have demonstrated that Cd exposure affects these pathways in different organ systems. This study was designed to investigate the effect of prenatal Cd exposure on thymocyte development, and to determine if these effects were linked to dysregulation of Shh and Wnt/β-catenin pathways. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose (10 ppm) of Cd throughout pregnancy and effects on the thymus were assessed on the day of birth. Thymocyte phenotype was determined by flow cytometry. A Gli:luciferase reporter cell line was used to measure Shh signaling. Transcription of target genes and translation of key components of both signaling pathways were assessed using real-time RT-PCR and western blot, respectively. Prenatal Cd exposure increased the number of CD4 + cells and a subpopulation of double-negative cells (DN; CD4 - CD8 - ), DN4 (CD44 - CD25 - ). Shh and Wnt/β-catenin signaling were both decreased in the thymus. Target genes of Shh (Patched1 and Gli1) and Wnt/β-catenin (c-fos, and c-myc) were affected differentially among thymocyte subpopulations. These findings suggest that prenatal exposure to Cd dysregulates two signaling pathways in the thymus, resulting in altered thymocyte development.

Enhancement of cell-cell contact by a nonmitogenic lectin increases blastogenic response and IL-2 release by mitogen-stimulated mouse thymocytes.

Science.gov (United States)

Favero, J; Marti, J; Dornand, J; Bonnafous, J C; Mani, J C

1986-03-01

We have examined the influence of peanut agglutinin (PNA), a lectin which agglutinates but does not stimulate mouse thymocytes, on the responsiveness of these cells to concanavalin A (Con A) or galactose oxidase stimulation. Binding low amounts of PNA on unseparated mouse thymocytes pretreated with neuraminidase highly enhances the mitogenic response and the level of interleukin 2 release in the culture medium upon Con A stimulation. We have shown that PNA present on the cell surface acts as a crosslinking agent which favors intercellular binding between accessory cells (macrophages) and thymocytes, leading through this enhanced cooperation by cell-cell contact to an enhanced blastogenic response.

Biophysical studies of irradiated thymocytes. 1. Surface changes

Energy Technology Data Exchange (ETDEWEB)

Sungurov, A Yu; Tokalov, S V; Petrov, Yu P; Sharlaeva, T M

1985-08-15

In order to study postirradiation changes in thymus lymphocyte surface, a number of biophysical analytical methods was used: the cell two-partition method, the physical adhesion method, fluorescence intensity and binding parameters of negatively charged ANS probe. Reduction of cell distribution factor in two-phase system and adhesion of thymocytes to cotton 1 hour after irradiation, as well as abrupt change in parameters of binding the probe in the interval of 3-4 hours after X-ray irradiation at the dose of 4 Gy are demonstrated.

DN2 Thymocytes Activate a Specific Robust DNA Damage Response to Ionizing Radiation-Induced DNA Double-Strand Breaks

Directory of Open Access Journals (Sweden)

Irene Calvo-Asensio

2018-06-01

Full Text Available For successful bone marrow transplantation (BMT, a preconditioning regime involving chemo and radiotherapy is used that results in DNA damage to both hematopoietic and stromal elements. Following radiation exposure, it is well recognized that a single wave of host-derived thymocytes reconstitutes the irradiated thymus, with donor-derived thymocytes appearing about 7 days post BMT. Our previous studies have demonstrated that, in the presence of donor hematopoietic cells lacking T lineage potential, these host-derived thymocytes are able to generate a polyclonal cohort of functionally mature peripheral T cells numerically comprising ~25% of the peripheral T cell pool of euthymic mice. Importantly, we demonstrated that radioresistant CD44+ CD25+ CD117+ DN2 progenitors were responsible for this thymic auto-reconstitution. Until recently, the mechanisms underlying the radioresistance of DN2 progenitors were unknown. Herein, we have used the in vitro “Plastic Thymus” culture system to perform a detailed investigation of the mechanisms responsible for the high radioresistance of DN2 cells compared with radiosensitive hematopoietic stem cells. Our results indicate that several aspects of DN2 biology, such as (i rapid DNA damage response (DDR activation in response to ionizing radiation-induced DNA damage, (ii efficient repair of DNA double-strand breaks, and (iii induction of a protective G1/S checkpoint contribute to promoting DN2 cell survival post-irradiation. We have previously shown that hypoxia increases the radioresistance of bone marrow stromal cells in vitro, at least in part by enhancing their DNA double-strand break (DNA DSB repair capacity. Since the thymus is also a hypoxic environment, we investigated the potential effects of hypoxia on the DDR of DN2 thymocytes. Finally, we demonstrate for the first time that de novo DN2 thymocytes are able to rapidly repair DNA DSBs following thymic irradiation in vivo.

Plxnd1 expression in thymocytes regulates their intrathymic migration while that in thymic endothelium impacts medullary topology

Directory of Open Access Journals (Sweden)

Young Il Choi

2013-11-01

Full Text Available An important role for plexinD1 in thymic development is inferred from studies of germline Plxnd1 knockout (KO mice where mislocalized CD69+ thymocytes as well as ectopic thymic subcapsular medullary structures were observed. Given embryonic lethality of the Plxnd1-/- genotype, fetal liver transplantation was employed in these prior analyses. Such embryonic hematopoietic reconstitution may have transferred Plxnd1 KO endothelial and/or epithelial stem cells in addition to Plxnd1 KO lymphoid progenitors, thereby contributing to that phenotype. Here we use Plxnd1flox/flox mice crossed to pLck-Cre, pKeratin14-Cre or pTek-Cre transgenic animals to create cell-type specific conditional knockout (CKO lines involving thymocytes (D1ThyCKO, thymic epithelium (D1EpCKO and thymic endothelium (D1EnCKO, respectively. These CKOs allowed us to directly assess the role of plexinD1 in each lineage. Loss of plexinD1 expression on double positive (DP thymocytes leads to their aberrant migration and cortical retention after TCR-mediated positive selection. In contrast, ectopic medulla formation is a consequence of loss of plexinD1 expression on endothelial cells, in turn linked to dysregulation of thymic angiogenesis. D1EpCKO thymi manifest neither abnormality. Collectively, our findings underscore the non-redundant roles for plexinD1 on thymocytes and endothelium, including the dynamic nature of medulla formation resulting from crosstalk between these thymic cellular components.

Cellular adverse actions of dibromoacetonitrile, a by-product in water bacterial control, at sublethal levels in rat thymocytes.

Science.gov (United States)

Kishida, Takumi; Akiyoshi, Kenji; Erdenedalai, Erdenebat; Enhetomuru, Anu; Imai, Shoji; Oyama, Yasuo

2018-09-01

The aim of this study was to investigate the effects of dibromoacetonitrile (DBAN), a by-product in water bacterial control, at sublethal concentrations on rat thymocytes, by using a cytometric technique with appropriate fluorescent dyes. By using this method, the possibility that DBAN induces cellular actions related to oxidative stress was assessed. DBAN reduced the content of cellular nonprotein thiols under Zn 2+ -free conditions. It elevated the intracellular level of Zn 2+ , being independent from external Zn 2+ . DBAN increased cell vulnerability to the cytotoxic action of hydrogen peroxide. These actions of DBAN were likely related to oxidative stress. DBAN is formed by the reaction of bromides and chlorinated oxidants during water disinfection. Hydrolysis of 2,2-dibromo-3-nitrilopropionamide, an antimicrobial used in hydraulic fracturing fluids for production of shale gas and oil, produces DBAN. Therefore, the concern regarding the levels of DBAN in industrial water systems is necessary to avoid the environmental risk to humans and wild mammals. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mtf-1 lymphoma-susceptibility locus affects retention of large thymocytes with high ROS levels in mice after γ-irradiation

International Nuclear Information System (INIS)

Maruyama, Masaki; Yamamoto, Takashi; Kohara, Yuki; Katsuragi, Yoshinori; Mishima, Yukio; Aoyagi, Yutaka; Kominami, Ryo

2007-01-01

Mouse strains exhibit different susceptibilities to γ-ray-induced thymic lymphomas. Our previous study identified Mtf-1 (metal responsive transcription factor-1) as a candidate susceptibility gene, which is involved in the radiation-induced signaling pathway that regulates the cellular reactive oxygen species (ROS). To reveal the mechanism for the increased susceptibility conferred by Mtf-1 locus, we examined early effects of γ-ray on ROS levels in vivo and its difference between Mtf-1 susceptible and resistant congenic mice. Here, we show the detection of clonally growing thymocytes at 4 weeks after irradiation, indicating the start of clonal expansion at a very early stage. We also show that large thymocytes with higher ROS levels and a proliferation capacity were more numerous in the Mtf-1 susceptible mice than the resistant mice when examined at 7 days after irradiation, although such tendency was not found in mice lacking one allele of Bcl11b tumor suppressor gene. This high retention of the large thymocytes, at a high risk for ROS-induced mutation, is a compensatory proliferation and regeneration response to depletion of the thymocytes after irradiation and the response is likely to augment the development of prelymphoma cells leading to thymic lymphomas

Mechanism of chromatin degradation in thymocytes of irradiated rats

International Nuclear Information System (INIS)

Nikonova, L.V.; Nelipovich, P.A.; Umanskij, S.R.

1983-01-01

Chromatin digestion in isolated thymocyte nuclei with DNAase I, micrococcal nuclease and nuclease from Serratia marcescens was studied. It was shown that 3 h after irradiation (10 Gy), the kinetics of accumulation of acid soluble and salt soluble products of DNA degradation, caused by exogenous nucleases, remains unchanged. The administration of cycloheximide does not influence the sensitivity of chromatin to DNAase I and somewhat increases the rate of salt soluble products formation upon the nuclease from S, marcescens treatment

Retinoic acid signalling in thymocytes regulates T cell development

DEFF Research Database (Denmark)

Wendland, Kerstin; Sitnik, Katarzyna Maria; Kotarsky, Knut

in the regulatory regions of targetgenes. RA has been reported to play a direct role in regulating multiple aspects of peripheralT cell responses1, but whether endogenous RA signalling occurs in developingthymocytes and the potential impact of such signals in regulating T cell developmentremains unclear. To address......RARα. This blocks RA signalling in developing thymocytes from the DN3/4 stageonwards and thus allows us to study the role of RA in T cell development...

Study in regularities in the formation of double stranded DNA breaks in irradiated rat thymocytes

International Nuclear Information System (INIS)

Ivannik, B.P.; ProskuryakoV, S.Ya.; Ryabchenko, N.I.

1979-01-01

Using low-gradient viscosimetry of neutral detergent nuclear lysates a study was made of postradiation changes in the molecular weight of double-stranded DNA of thymocytes. It was established that 375 eV are needed for one double-stranded break to appear, and a dose of 1 rad is required for 0.275 double-stranded break to occur at the site of DNA with m.w. 10 12 dalton. The repair of double-stranded breaks is only observed when rats are exposed to a dose of 500 R. It is assumed that the absence of repair of double-stranded DNA breaks and the presence of secondary postradiation degradation of DNA are responsible for thymocyte death

Thermophysical Properties of Mars' North Polar Layered Deposits and Related Materials from Mars Odyssey THEMIS

Science.gov (United States)

Vasavada, A. R.; Richardson, M. I.; Byrne, S.; Ivanov, A. B.; Christensen, P. R.

2003-01-01

The presence of a thick sequence of horizontal layers of ice-rich material at Mars north pole, dissected by troughs and eroding at its margins, is undoubtedly telling us something about the evolution of Mars climate [1,2] we just don t know what yet. The North Polar Layered Deposits (NPLD) most likely formed as astronomically driven climate variations led to the deposition of conformable, areally extensive layers of ice and dust over the polar region. More recently, the balance seems to have fundamentally shifted to net erosion, as evidenced by the many troughs within the NPLD and the steep, arcuate scarps present near its margins, both of which expose layering. We defined a number of Regions of Interest ROI) for THEMIS to target as part of the Mars Odyssey Participating Scientist program. We use these THEMIS data in order to understand the morphology and color/thermal properties of the NPLD and related materials over relevant (i.e., m to km) spatial scales. We have assembled color mosaics of our ROIs in order to map the distribution of ices, the different layered units, dark material, and underlying basement. The color information from THEMIS is crucial for distinguishing these different units which are less distinct on Mars Orbiter Camera images. We wish to understand the nature of the marginal scarps and their relationship to the dark material. Our next, more ambitious goal is to derive the thermophysical properties of the different geologic materials using THEMIS and Mars Global Surveyor Thermal Emission Spectrometer TES) data.

Prominence and tornado dynamics observed with IRIS and THEMIS

Science.gov (United States)

Schmieder, Brigitte; Levens, Peter; Labrosse, Nicolas; Mein, Pierre; Lopez Ariste, Arturo; Zapior, Maciek

2017-08-01

Several prominences were observed during campaigns in September 2013 and July 2014 with the IRIS spectrometer and the vector magnetograph THEMIS (Tenerife). SDO/AIA and IRIS provided images and spectra of prominences and tornadoes corresponding to different physical conditions of the transition region between the cool plasma and the corona. The vector magnetic field was derived from THEMIS observations by using the He D3 depolarisation due to the magnetic field. The inversion code (PCA) takes into account the Hanle and Zeeman effects and allows us to compute the strength and the inclination of the magnetic field which is shown to be mostly horizontal in prominences as well as in tornadoes. Movies from SDO/AIA in 304 A and Hinode/SOT in Ca II show the highly dynamic nature of the fine structures. From spectra in Mg II and Si IV lines provided by IRIS and H-alpha observed by the Multi-channel Subtractive Double Pass (MSDP) spectrograph in the Meudon Solar Tower we derived the Doppler shifts of the fine structures and reconstructed the 3D structure of tornadoes. We conclude that the apparent rotation of AIA tornadoes is due to large-scale quasi-periodic oscillations of the plasma along more or less horizontal magnetic structures.

NASA's THEMIS Mission: Multipoint Observations of Substorms, the Foreshock, and the Magnetopause

Science.gov (United States)

Sibeck, D. G.; Angelopoulos, V.; Kuznetsova, M.; Glabmeier, K.-H.; McFadden. J. P.

2008-01-01

From launch on February 17 through the repositioning to final orbits that began in September 2007, the five-spacecraft of the THEMIS mission operated nominally in nearly identical 14.6 RE apogee near-equatorial orbits. On March 23, while aligned from east to west in the duskside magnetotail, the spacecraft observed two substorm sequences in fast survey mode. Timing the motion of these signatures served as an early proof of concept for the main phase of the mission: particle injection and dipolarization signatures propagated duskward from one probe to another, as did auroral intensifications seen by the dedicated array of ground-based observatories. During the summer of 2007, the spacecraft were on the dayside, where the three inner spacecraft (C, D, E) were separated by 100-500 km and the two outer probes (B, -4) by 5,000 - 10,000 km. Here the THEMIS probes repeatedly encountered the magnetopause and bow shock, dissecting flux transfer events (FTEs), determining the instantaneous width of the low-latitude boundary layer, and simultaneously observing hot flow anomalies upstream and downstream from the bow shock at the moment of their inception. From January to March 2008, the spacecraft were in the Earths magnetotail with apogees of 31.0, 19.5, 11.8 (2) and 10.0 RE corresponding to periods of 4, 2, and 1 days. Radial alignments once each four days offered an opportunity to pinpoint when and where substorms begin. This talk reviews THEMIS discoveries to date, with an emphasis on model-data comparisons of FTE characteristics

[Effect of irradiation on the degradation of rat thymocyte chromatin].

Science.gov (United States)

Tsudzevich, B O; Parkhomets', Iu P; Andriĭchuk, T R; Iurkina, V V

1998-01-01

Genome instability of adaptive nature is formed under the experimental influence on a cell. Under critical conditions, strategy of organism is to damage the cells that cannot be restored and controlled by including the program of apoptosis. The ordered internucleosomal DNA degradation is considered to be one of the proof attributes of immunocompetent cell apoptosis. We investigated the effects of various doses of irradiation on the thymocytes chromatine fragmentation in 1,2,3 hours after a single X-ray exposure or after chronic influence in conditions of Chernobyl research base. By the means of electrophoresis in agarose and judging by polydeoxyribonucleotides accumulation we observed the "ladder pattern" of degradation in 3 hr after single 1 Gr irradiation (the smallest dose displaying the effect). We suppose that the influence of both chronic low-intensity irradiation taking place in Chernobyl and single X-ray exposure result in intensifying of DNA fragmentation in the cells of immunocompetent organs.

Apoptosis and survival parameters during protection from radiation-induced thymocyte death by a candidate radioprotector, GC-2112, from Allium sativum

International Nuclear Information System (INIS)

Bunagan, J.; Perey, K.; Deocaris, C.C.

1996-01-01

Biomedical studies on nuclear fallout effects show that whole-body exposure to relatively low doses of ionizing radiation (2-10 Gy) induces the hematopoietic syndrome (HS) characterized by severe anemia and immunodeficiency and death within 10-30 days. The thymocyte model applies in many cell death researches and is found to undergo a morphologically and molecularly distinct p53-based apoptosis with DNA-damaging insults, such as radiation exposure. We have shown that exogenously applied radioprotector from allium sativum (garlic), GC-2112, improves total cellular survival for various observation periods concomitantly shifting the LD 50/24 from 7 Gy (control) to 21 Gy (GC-2112). This increased survival characteristic of the radioprotected macrophage-free thymocytes, however, fails to correlate with the prevention of apoptosis-associated DNA scissions. Mechanisms to the observed radiomodification may possibly involve cysteine compounds found rich in garlic. These preliminary findings show promise in the applications of selected herbal drugs as dietary prophylaxis against clinical morbidities arising from either medical, occupational or environmental exposures to ionizing radiation. (author)

Apoptosis and survival parameters during protection from radiation-induced thymocyte death by a candidate radioprotector, GC-2112, from Allium sativum

Energy Technology Data Exchange (ETDEWEB)

Bunagan, J; Perey, K [Pamantasan ng Lungsod ng Maynila, Manila (Philippines); Deocaris, C C [Philippine Nuclear Research Inst., Diliman, Quezon City (Philippines)

1997-12-31

Biomedical studies on nuclear fallout effects show that whole-body exposure to relatively low doses of ionizing radiation (2-10 Gy) induces the hematopoietic syndrome (HS) characterized by severe anemia and immunodeficiency and death within 10-30 days. The thymocyte model applies in many cell death researches and is found to undergo a morphologically and molecularly distinct p53-based apoptosis with DNA-damaging insults, such as radiation exposure. We have shown that exogenously applied radioprotector from allium sativum (garlic), GC-2112, improves total cellular survival for various observation periods concomitantly shifting the LD{sub 50/24} from 7 Gy (control) to 21 Gy (GC-2112). This increased survival characteristic of the radioprotected macrophage-free thymocytes, however, fails to correlate with the prevention of apoptosis-associated DNA scissions. Mechanisms to the observed radiomodification may possibly involve cysteine compounds found rich in garlic. These preliminary findings show promise in the applications of selected herbal drugs as dietary prophylaxis against clinical morbidities arising from either medical, occupational or environmental exposures to ionizing radiation. (author).

Cross-scale observations of the 2015 St. Patrick's day storm: THEMIS, Van Allen Probes, and TWINS

International Nuclear Information System (INIS)

Goldstein, J.

2016-01-01

In this paper, we present cross-scale magnetospheric observations of the 17 March 2015 (St. Patrick's Day) storm, by Time History of Events and Macroscale Interactions during Substorms (THEMIS), Van Allen Probes (Radiation Belt Storm Probes), and Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS), plus upstream ACE/Wind solar wind data. THEMIS crossed the bow shock or magnetopause 22 times and observed the magnetospheric compression that initiated the storm. Empirical models reproduce these boundary locations within 0.7 R E . Van Allen Probes crossed the plasmapause 13 times; test particle simulations reproduce these encounters within 0.5 R E . Before the storm, Van Allen Probes measured quiet double-nose proton spectra in the region of corotating cold plasma. About 15 min after a 0605 UT dayside southward turning, Van Allen Probes captured the onset of inner magnetospheric convection, as a density decrease at the moving corotation-convection boundary (CCB) and a steep increase in ring current (RC) proton flux. During the first several hours of the storm, Van Allen Probes measured highly dynamic ion signatures (numerous injections and multiple spectral peaks). Sustained convection after ~1200 UT initiated a major buildup of the midnight-sector ring current (measured by RBSP A), with much weaker duskside fluxes (measured by RBSP B, THEMIS a and THEMIS d). A close conjunction of THEMIS d, RBSP A, and TWINS 1 at 1631 UT shows good three-way agreement in the shapes of two-peak spectra from the center of the partial RC. A midstorm injection, observed by Van Allen Probes and TWINS at 1740 UT, brought in fresh ions with lower average energies (leading to globally less energetic spectra in precipitating ions) but increased the total pressure. Finally, the cross-scale measurements of 17 March 2015 contain significant spatial, spectral, and temporal structure.

Cytotoxic T lymphocyte responses by chimeric thymocytes. Self-recognition is determined early in T cell development

International Nuclear Information System (INIS)

Kruisbeek, A.M.; Hodes, R.J.; Singer, A.

1981-01-01

In this study the cytotoxic T lymphocyte (CTL) recognition pattern of thymocytes from recently reconstituted parent leads to F1 and F1 leads to parent radiation bone marrow chimeras was investigated. Chimeric thymocytes were entirely of donor origin approximately 4 weeks after irradiation and reconstitution but were not capable of autonomously generating either alloreactive or trinitrophenyl (TNP)-modified-self-reactive CTL responses. These experiments demonstrte that even at the earliest time CTL effectors of donor origin from the thymuses of chimeras can be studied, their self-receptor repertoire has already been restricted to recognition of host MHC determinants. These results support the cocept that the host environment influences the self-recognition capacity of T cells at the pre- or intrathymic stage of differentation

In vitro analysis of age-related changes in the developmental potential of bone marrow thymocyte progenitors.

Science.gov (United States)

Sharp, A; Kukulansky, T; Globerson, A

1990-12-01

Mechanisms underlying the age-related decrease in the developmental capacity of thymocyte progenitors from the bone marrow (BM) were analyzed, focussing on interaction of these cells with the thymic microenvironment. We employed the experimental model in which mixtures of young and old mouse BM cells, congenic for the Thy-1 marker, were seeded onto fetal thymus (FT) explains depleted of self lymphocytes and the levels of Thy-1+ cells developing from each of the two donor types were measured. When cells from young and old BM donors were seeded simultaneously, in saturating quantities, a higher level of T cells developed from the young donors. To find out whether there were originally more thymocyte progenitors in the young BM, we carried out the competitive colonization under limiting dilution conditions and found that the advantage of the young had diminished under these conditions, thus suggesting that the age-related changes could not be related solely to quantitative differences. We then incubated the FT sequentially with old donor cells for 24 h, followed by young for an additional 48 h and found that the advantage of the young progenitors was eliminated. We thus established that the initial stage of colonization of the FT was important in determining the outcome of the subsequent development. The kinetics of simultaneous competition within the FT, however, revealed that the advantage of the young BM-derived cells became significant only from day 7 in organ culture, thus suggesting that sequential divisions of these cells were at a higher level than those of the old. Recolonization of FT explants by young or old BM-derived thymocytes obtained from the first colonization of the FT stroma showed a reduced, but still significant advantage for the young BM-derived cells over the old. Thus, we concluded that the old BM thymocyte progenitors manifested a qualitative disadvantage which became apparent during competitive colonization of the FT.

Proceedings of the Seminar on NJOY and THEMIS

International Nuclear Information System (INIS)

1989-01-01

Nuclear evaluated data processing codes are essential tools for the interpretation of basic data stored in files with formats reflecting the complex intrinsic structure of the data. They help users to filter out data and condense it to a form suitable to the physicist and engineer for nuclear application studies. The quality of evaluated data files can be determined by comparing their performance in predicting measured integral quantities. Evaluated data processing is an essential part in this benchmarking activity. Several tools have been developed over the years, but NJOY has taken up an eminent role because of its comprehensive set of features. NJOY and the French version THEMIS have been adopted as the standard processing codes for the JEF project. Considerable experience has been gained over the years from the different releases of NJOY and THEMIS. An important factor contributing to the improvements introduced has been the feedback provided by the users to the authors. The new format ENDF-6 adopted for the new evaluations led to a complete revision of NJOY which was recently released. It was therefore considered timely to organise a seminar in which the code developers and users could exchange information on: - the new features introduced in the most recent version - experience gained and validation of the different processing modules - maintenance, future developments and their co-ordination While a first workshop (1982) aimed at making NJOY known to the user community, the present seminar was aimed at experienced users. About thirty participants have attended the seminar and have contributed interesting presentations and lively discussions

THEMIS analysis of Olympus Mons' mineralogical makeup

Science.gov (United States)

Chase, N. D.

2016-12-01

Olympus Mons is the largest shield volcano in our known solar system. In previous studies, the composition of the basaltic lava flows on Olympus Mons was shown to be similar to the composition of those lava flows of Earth's shield volcanoes. It has been suggested that basalt located near volcanoes contained bacteria living below the surface of the Earth. In this pilot study, the effect of Olympus Mons' aspect (i.e. north- vs. south-facing slope) on its mineral composition was examined. Imagery from Thermal Emission Imaging System (THEMIS), onboard the 2001 Mars Odyssey spacecraft, were used because Olympus Mons' size and surface roughness hinder rover exploration. After removing transmission errors and performing an atmospheric correction, the THEMIS images were ready to be analyzed via a mineral spectral library. Using Arizona State University's Thermal Emission Spectrometer (TES) derived mineral spectral library, the images were classified in ENVI. These classifications were verified using ASU's GIS tool, Java Mission-planning and Analysis for Remote Sensing (JMARS) and TES. Results show a significant amount of silicates located throughout the sampled areas of Olympus Mons. The results also show differences in the mineral composition and in the geological features on Olympus Mons' surface. The minerals vanadinite and halloysite were shown to be prevalent on the sampled southern portions of Olympus Mons, but were sparse on the sampled northern portions. Previous studies suggested that the mineral ilmenite, which this study found in high concentrations on the sampled northern portions of Olympus Mons, might serve as a food source for iron-oxidizing and iron-scavenging bacteria. Future research should focus on better understanding these concentrations on Olympus Mons to see if these minerals play a role in the potential bacterial presence on Olympus Mons.

THEMIS-4: a coherent punctual and multigroup cross section library for Monte Carlo and SN codes from ENDF/B4

International Nuclear Information System (INIS)

Dejonghe, G.; Gonnord, J.; Monnier, A.; Nimal, J.C.

1983-05-01

The THEMIS cross section processing system has been developped to produce punctual data for MONTE CARLO and coherent multigroup data for SN codes from ENDF/B. The THEMIS-4 data base has been generated from ENDF/B4 using the system and can be accessed by the 3-D Monte Carlo system TRIPOLI-2 and by the SN codes ANISN and DOT. An interpretation of ORNL fusion shielding benchmark is presented

6-methylprednisolone does not impair anti-thymocyte globulin (ATG) immunosuppressive activity in non-human primates

NARCIS (Netherlands)

Preville, [No Value; Sick, E; Beauchard, S; Ossevoort, M; Tiollier, J; Revillard, JP; Jonker, Margreet

2001-01-01

Background: Induction treatments with anti-thymocyte globulin (ATG) in solid organ transplantation may enhance the efficacy of maintenance immunosuppressive therapy. Since ATG can trigger Fas (CD95) mediated T cell apoptosis, a process antagonized in vitro by corticosteroids, an important issue is

Molecular dynamics study of lipid bilayers modeling the plasma membranes of normal murine thymocytes and leukemic GRSL cells.

Science.gov (United States)

Andoh, Yoshimichi; Okazaki, Susumu; Ueoka, Ryuichi

2013-04-01

Molecular dynamics (MD) calculations for the plasma membranes of normal murine thymocytes and thymus-derived leukemic GRSL cells in water have been performed under physiological isothermal-isobaric conditions (310.15K and 1 atm) to investigate changes in membrane properties induced by canceration. The model membranes used in our calculations for normal and leukemic thymocytes comprised 23 and 25 kinds of lipids, respectively, including phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, lysophospholipids, and cholesterol. The mole fractions of the lipids adopted here were based on previously published experimental values. Our calculations clearly showed that the membrane area was increased in leukemic cells, and that the isothermal area compressibility of the leukemic plasma membranes was double that of normal cells. The calculated membranes of leukemic cells were thus considerably bulkier and softer in the lateral direction compared with those of normal cells. The tilt angle of the cholesterol and the conformation of the phospholipid fatty acid tails both showed a lower level of order in leukemic cell membranes compared with normal cell membranes. The lateral radial distribution function of the lipids also showed a more disordered structure in leukemic cell membranes than in normal cell membranes. These observations all show that, for the present thymocytes, the lateral structure of the membrane is considerably disordered by canceration. Furthermore, the calculated lateral self-diffusion coefficient of the lipid molecules in leukemic cell membranes was almost double that in normal cell membranes. The calculated rotational and wobbling autocorrelation functions also indicated that the molecular motion of the lipids was enhanced in leukemic cell membranes. Thus, here we have demonstrated that the membranes of thymocyte leukemic cells are more disordered and more fluid than normal cell membranes. Copyright © 2013

S1P lyase in thymic perivascular spaces promotes egress of mature thymocytes via up-regulation of S1P receptor 1.

Science.gov (United States)

Maeda, Yasuhiro; Yagi, Hideki; Takemoto, Kana; Utsumi, Hiroyuki; Fukunari, Atsushi; Sugahara, Kunio; Masuko, Takashi; Chiba, Kenji

2014-05-01

Sphingosine 1-phosphate (S1P) and S1P receptor 1 (S1P1) play an important role in the egress of mature CD4 or CD8 single-positive (SP) thymocytes from the thymus. Fingolimod hydrochloride (FTY720), an S1P1 functional antagonist, induced significant accumulation of CD62L(high)CD69(low) mature SP thymocytes in the thymic medulla. Immunohistochemical staining using anti-S1P1 antibody revealed that S1P1 is predominantly expressed on thymocytes in the thymic medulla and is strongly down-regulated even at 3h after FTY720 administration. 2-Acetyl-4-tetrahydroxybutylimidazole (THI), an S1P lyase inhibitor, also induced accumulation of mature SP thymocytes in the thymic medulla with an enlargement of the perivascular spaces (PVS). At 6h after THI administration, S1P1-expressing thymocytes reduced partially as if to form clusters and hardly existed in the proximity of CD31-expressing blood vessels in the thymic medulla, suggesting S1P lyase expression in the cells constructing thymic medullary PVS. To determine the cells expressing S1P lyase in the thymus, we newly established a mAb (YK19-2) specific for mouse S1P lyase. Immunohistochemical staining with YK19-2 revealed that S1P lyase is predominantly expressed in non-lymphoid thymic stromal cells in the thymic medulla. In the thymic medullary PVS, S1P lyase was expressed in ER-TR7-positive cells (reticular fibroblasts and pericytes) and CD31-positive vascular endothelial cells. Our findings suggest that S1P lyase expressed in the thymic medullary PVS keeps the tissue S1P concentration low around the vessels and promotes thymic egress via up-regulation of S1P1.

Toxicity of organotin compounds : IV. Impairment of energy metabolism of rat thymocytes by various dialkyltin compounds

NARCIS (Netherlands)

Penninks, A.H.

2006-01-01

Isolated thymocytes were incubated with various carbohydrates in the presence of dimethyltindichloride (DMTC), diethyltindichloride (DETC), di-n-butyltindichloride (DBTC), and di-n-octyltindichloride (DOTC) and the substrate conversion, oxygen consumption, and cell viability were measured. All the

Chorus source region localization in the Earth's outer magnetosphere using THEMIS measurements

Directory of Open Access Journals (Sweden)

O. Agapitov

2010-06-01

Full Text Available Discrete ELF/VLF chorus emissions, the most intense electromagnetic plasma waves observed in the Earth's radiation belts and outer magnetosphere, are thought to propagate roughly along magnetic field lines from a localized source region near the magnetic equator towards the magnetic poles. THEMIS project Electric Field Instrument (EFI and Search Coil Magnetometer (SCM measurements were used to determine the spatial scale of the chorus source localization region on the day side of the Earth's outer magnetosphere. We present simultaneous observations of the same chorus elements registered onboard several THEMIS spacecraft in 2007 when all the spacecraft were in the same orbit. Discrete chorus elements were observed at 0.15–0.25 of the local electron gyrofrequency, which is typical for the outer magnetosphere. We evaluated the Poynting flux and wave vector distribution and obtained chorus wave packet quasi-parallel propagation to the local magnetic field. Amplitude and phase correlation data analysis allowed us to estimate the characteristic spatial correlation scale transverse to the local magnetic field to be in the 2800–3200 km range.

Human natural killer cell committed thymocytes and their relation to the T cell lineage

NARCIS (Netherlands)

Sánchez, M. J.; Spits, H.; Lanier, L. L.; Phillips, J. H.

1993-01-01

Recent studies have demonstrated that mature natural killer (NK) cells can be grown from human triple negative (TN; CD3-, CD4-, CD8-) thymocytes, suggesting that a common NK/T cell precursor exists within the thymus that can give rise to both NK cells and T cells under appropriate conditions. In the

A simulation study of particle energization observed by THEMIS spacecraft during a substorm

Science.gov (United States)

Ashour-Abdalla, Maha; Bosqued, Jean-Michel; El-Alaoui, Mostafa; Peroomian, Vahe; Zhou, Meng; Richard, Robert; Walker, Raymond; Runov, Andrei; Angelopoulos, Vassilis

2009-09-01

Energetic ions with hundreds of keV energy are frequently observed in the near-Earth tail during magnetospheric substorms. We examined the sources and acceleration of ions during a magnetospheric substorm on 1 March 2008 by using Time History of Events and Macroscale Interactions during Substorms (THEMIS) and Cluster observations and numerical simulations. Four of the THEMIS spacecraft were aligned at yGSM = 6 RE during a very large substorm (AE = 1200) while the Cluster spacecraft were located about 5 RE above the auroral ionosphere. For 2 h before the substorm, Cluster observed ionospheric oxygen flowing out into the magnetosphere. After substorm onset the THEMIS P3 and P4 spacecraft located in the near-Earth tail (xGSM = -9 RE and -8 RE, respectively) observed large fluxes of energetic ions up to 500 keV. We used calculations of millions of ions of solar wind and ionospheric origin in the time-dependent electric and magnetic fields from a global magnetohydrodynamic simulation of this event to study the source of these ions and their acceleration. The simulation did a good job of reproducing the particle observations. Both solar wind protons and ionospheric oxygen were accelerated by nonadiabatic motion across large (>˜5 mV/m) total electric fields (both potential and induced). The acceleration occurred in the "wall" region of the near-Earth tail where nonadiabatic motion dominates over convection and the particles move rapidly across the tail. The acceleration occurred mostly in regions with large electric fields and nonadiabatic motion. There was relatively little acceleration in regions with large electric fields and adiabatic motion or small electric fields and nonadiabatic motion. Prior to substorm onset, ionospheric ions were a significant contributor to the cross-tail current, but after onset, solar wind ions become more dominant.

T cell antigen receptor expression by subsets of Ly-2-L3T4- (CD8-CD4-) thymocytes

DEFF Research Database (Denmark)

Wilson, A; Ewing, T; Owens, T

1988-01-01

. No positive cells were detected among Ly-2-L3T4- thymocytes from V beta 8-negative SJL mice. In contrast to the adult thymus, Ly-2-L3T4- cells from embryonic CBA thymus lacked F23.1-positive cells. Subsets of adult CBA Ly-2-L3T4- thymocytes were separated to determine which expressed V beta 8. The major...... B2A2-M1/69- and Pgp-1+ all included strongly F23.1-positive cells. A minor subset, negative for most markers except Pgp-1 and presumed on the basis of this phenotype and some reconstitution studies to include the earliest intrathymic precursors, contained 28% F23.1-positive cells. However, no F.23...

Ontogeny of the thymus in a teleost fish, Cyprinus carpio L.: developing thymocytes in the epithelial microenvironment.

Science.gov (United States)

Romano, N; Taverne-Thiele, A J; Fanelli, M; Baldassini, M R; Abelli, L; Mastrolia, L; Van Muiswinkel, W B; Rombout, J H

1999-01-01

A monoclonal antibody, WCL9, specific for membrane molecules of a thymocyte subpopulation was used to detect these cells in situ during the ontogeny of thymus. Cryo-sections revealed WCL9+ cells in the rudiment of the thymus (day 4 post fertilization); thereafter, the positive cells were observed exclusively in the cortex from the first appearance of thymic regionalization (week 4 post fertilization) until adult age. Whole-mount immunostaining of the thymus with WCL9 revealed the three-dimensional structure of the cortex by specific staining. The presence and distribution of apoptotic cells during thymus development was studied by in situ end-labelling of fragmented DNA. From week 4 post fertilization onwards, apoptotic cells were more frequently detected in the cortex than medulla, suggesting a continuous selection of thymocytes in the cortex. Ultrastructural studies confirmed the presence of numerous cortical apoptotic cells inside macrophages. Electron microscopy provided evidence for the existence of epithelial heterogeneity in the thymus. During the ontogeny, the differentiation of epithelial cells was followed from the first weeks until the juvenile age. Cell types were classified on the basis of their localization and cytological characteristics as: i) limiting epithelial cells located in subcapsular, perivascular and peritrabecular zones; ii) reticular epithelial cells situated in medullary and cortical zones; iii) nurse-like cells at the border between the cortex and medulla, iiii) Hassall's body-like structures localized in the medulla. This study could suggest the occurrence of a wide range of lympho-epithelial interactions throughout thymocytes differentiation.

Modulatory effect of curcumin on ketamine-induced toxicity in rat thymocytes: Involvement of reactive oxygen species (ROS and the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway

Directory of Open Access Journals (Sweden)

Svetlana Pavlovic

2018-03-01

Full Text Available Ketamine is a widely used anesthetic in pediatric clinical practice. Previous studies have demonstrated that ketamine induces neurotoxicity and has a modulatory effect on the cells of the immune system. Here, we evaluated the potential protective effect and underlying mechanisms of natural phenolic compound curcumin against ketamine-induced toxicity in rat thymocytes. Rat thymocytes were exposed to 100 µM ketamine alone or combined with increasing concentrations of curcumin (0.3, 1, and 3 μM for 24 hours. Cell viability was analyzed with CCK-8 assay kit. Apoptosis was analyzed using flow cytometry and propidium iodide as well as Z-VAD-FMK and Z-LEHD-FMK inhibitors. Reactive oxygen species (ROS production and mitochondrial membrane potential [MMP] were measured by flow cytometry. Colorimetric assay with DEVD-pNA substrate was used for assessing caspase-3 activity. Involvement of phosphoinositide 3-kinase (PI3K/protein kinase B (Akt signaling pathway was tested with Wortmannin inhibitor. Ketamine induced toxicity in cells, increased the number of hypodiploid cells, caspase-3 activity and ROS production, and inhibited the MMP. Co-incubation of higher concentrations of curcumin (1 and 3 μM with ketamine markedly decreased cytotoxicity, apoptosis rate, caspase-3 activity, and ROS production in rat thymocytes, and increased the MMP. Application of Z-VAD-FMK (a pan caspase inhibitor or Z-LEHD-FMK (caspase-9 inhibitor with ketamine effectively attenuated the ketamine-induced apoptosis in rat thymocytes. Administration of Wortmannin (a PI3K inhibitor with curcumin and ketamine significantly decreased the protective effect of curcumin on rat thymocytes. Our results indicate that ketamine-induced toxicity in rat thymocytes mainly occurs through the mitochondria-mediated apoptotic pathway and that the PI3K/Akt signaling pathway is involved in the anti-apoptotic effect of curcumin.

Quantitative and Qualitative Changes in V-J α Rearrangements During Mouse Thymocytes Differentiation

Science.gov (United States)

Pasqual, Nicolas; Gallagher, Maighréad; Aude-Garcia, Catherine; Loiodice, Mélanie; Thuderoz, Florence; Demongeot, Jacques; Ceredig, Rod; Marche, Patrice Noël; Jouvin-Marche, Evelyne

2002-01-01

Knowledge of the complete nucleotide sequence of the mouse TCRAD locus allows an accurate determination V-J rearrangement status. Using multiplex genomic PCR assays and real time PCR analysis, we report a comprehensive and systematic analysis of the V-J recombination of TCR α chain in normal mouse thymocytes during development. These respective qualitative and quantitative approaches give rise to four major points describing the control of gene rearrangements. (a) The V-J recombination pattern is not random during ontogeny and generates a limited TCR α repertoire; (b) V-J rearrangement control is intrinsic to the thymus; (c) each V gene rearranges to a set of contiguous J segments with a gaussian-like frequency; (d) there are more rearrangements involving V genes at the 3′ side than 5′ end of V region. Taken together, this reflects a preferential association of V and J gene segments according to their respective positions in the locus, indicating that accessibility of both V and J regions is coordinately regulated, but in different ways. These results provide a new insight into TCR α repertoire size and suggest a scenario for V usage during differentiation. PMID:12417627

Clonally Expanding Thymocytes Having Lineage Capability in Gamma-Ray-Induced Mouse Atrophic Thymus

International Nuclear Information System (INIS)

Yamamoto, Takashi; Morita, Shin-ichi; Go, Rieka; Obata, Miki; Katsuragi, Yoshinori; Fujita, Yukari; Maeda, Yoshitaka; Yokoyama, Minesuke; Aoyagi, Yutaka; Ichikawa, Hitoshi; Mishima, Yukio; Kominami, Ryo

2010-01-01

Purpose: To characterize, in the setting of γ-ray-induced atrophic thymus, probable prelymphoma cells showing clonal growth and changes in signaling, including DNA damage checkpoint. Methods and Materials: A total of 111 and 45 mouse atrophic thymuses at 40 and 80 days, respectively, after γ-irradiation were analyzed with polymerase chain reaction for D-J rearrangements at the TCRβ locus, flow cytometry for cell cycle, and Western blotting for the activation of DNA damage checkpoints. Results: Limited D-J rearrangement patterns distinct from normal thymus were detected at high frequencies (43 of 111 for 40-day thymus and 21 of 45 for 80-day thymus). Those clonally expanded thymocytes mostly consisted of CD4 + CD8 + double-positive cells, indicating the retention of lineage capability. They exhibited pausing at a late G1 phase of cell cycle progression but did not show the activation of DNA damage checkpoints such as γH2AX, Chk1/2, or p53. Of interest is that 17 of the 52 thymuses showing normal D-J rearrangement patterns at 40 days after irradiation showed allelic loss at the Bcl11b tumor suppressor locus, also indicating clonal expansion. Conclusion: The thymocytes of clonal growth detected resemble human chronic myeloid leukemia in possessing self-renewal and lineage capability, and therefore they can be a candidate of the lymphoma-initiating cells.

Notch3 is dispensable for thymocyte β-selection and Notch1-induced T cell leukemogenesis.

Directory of Open Access Journals (Sweden)

Sara Suliman

Full Text Available Notch1 (N1 signaling induced by intrathymic Delta-like (DL ligands is required for T cell lineage commitment as well as self-renewal during "β-selection" of TCRβ⁺CD4⁻CD8⁻ double negative 3 (DN3 T cell progenitors. However, over-expression of the N1 intracellular domain (ICN1 renders N1 activation ligand-independent and drives leukemic transformation during β-selection. DN3 progenitors also express Notch3 (N3 mRNA, and over-expression of ligand-independent mutant N3 (ICN3 influences β-selection and drives T cell leukemogenesis. However, the importance of ligand-activated N3 in promoting β-selection and ICN1-induced T cell leukemogenesis has not been examined. To address these questions we generated mice lacking functional N3. We confirmed that DN3 progenitors express N3 protein using a N3-specific antibody. Surprisingly however, N3-deficient DN3 thymocytes were not defective in generating DP thymocytes under steady state conditions or in more stringent competition assays. To determine if N3 co-operates with N1 to regulate β-selection, we generated N1;N3 compound mutants. However, N3 deficiency did not exacerbate the competitive defect of N1⁺/⁻ DN3 progenitors, demonstrating that N3 does not compensate for limiting N1 during T cell development. Finally, N3 deficiency did not attenuate T cell leukemogenesis induced by conditional expression of ICN1 in DN3 thymocytes. Importantly, we showed that in contrast to N1, N3 has a low binding affinity for DL4, the most abundant intrathymic DL ligand. Thus, despite the profound effects of ectopic ligand-independent N3 activation on T cell development and leukemogenesis, physiologically activated N3 is dispensable for both processes, likely because N3 interacts poorly with intrathymic DL4.

THEMIS Global Mosaics

Science.gov (United States)

Gorelick, N. S.; Christensen, P. R.

2005-12-01

We have developed techniques to make seamless, controlled global mosaics from the more than 50,000 multi-spectral infrared images of the Mars returned by the THEMIS instrument aboard the Mars Odyssey spacecraft. These images cover more than 95% of the surface at 100m/pixel resolution at both day and night local times. Uncertainties in the position and pointing of the spacecraft, varying local time, and imaging artifacts make creating well-registered mosaics from these datasets a challenging task. In preparation for making global mosaics, many full-resolution regional mosaics have been made. These mosaics typically cover an area 10x10 degrees or smaller, and are constructed from only a few hundred images. To make regional mosaics, individual images are geo-rectified using the USGS ISIS software. This dead-reckoning is sufficient to approximate position to within 400m in cases where the SPICE information was downlinked. Further coregistration of images is handled in two ways: grayscale differences minimization in overlapping regions through integer pixel shifting, or through automatic tie-point generation using a radial symmetry transformation (RST). The RST identifies points within an image that exhibit 4-way symmetry. Martian craters tend to to be very radially symmetric, and the RST can pin-point a crater center to sub-pixel accuracy in both daytime and nighttime images, independent of lighting, time of day, or seasonal effects. Additionally, the RST works well on visible-light images, and in a 1D application, on MOLA tracks, to provide precision tie-points across multiple data sets. The RST often finds many points of symmetry that aren't related to surface features. These "false-hits" are managed using a clustering algorithm that identifies constellations of points that occur in multiple images, independent of scaling or other affine transformations. This technique is able to make use of data in which the "good" tie-points comprise even less than 1% of total

Cell proliferation and thymocyte subset reconstitution in sublethally irradiated mice: Compared kinetics of endogenous and intrathymically transferred progenitors

International Nuclear Information System (INIS)

Penit, C.; Ezine, S.

1989-01-01

After sublethal (6 Gy) whole-body irradiation, the C57BL/Ba (Thy-1.1) murine thymus regenerated in two waves, on days 3-10 and 25-32, separated by a severe relapse. The second phase of depletion-reconstitution reproduced the first one, in a less synchronous manner. The depletion affected all cell subsets, but CD4+ CD8- cells decreased later than immature cells. Cell proliferation, measured by BrdUrd incorporation, started on day 3 after irradiation and concerned CD4- CD8-, CD4- CD8+, and CD4+ CD8+ cells, sequentially. CD4+ CD8- cells never represented a significant percentage of cycling cells. When irradiation was immediately followed by an intrathymic injection of 10(5) C57BL/Ka (Thy-1.2) bone marrow cells, the relapse in thymus reconstitution was no longer observed. Detected with anti-Thy-1.2 antibodies, donor cells started cycling on day 14 and showed only one wave of proliferation. In these chimeras, recipient thymocytes behave exactly like thymocytes of solely irradiated mice. Intrathymically transferred CD4- CD8- thymocytes 10(5) showed the same proliferation kinetics as endogenous cells, with a peak in number on day 10 but completely disappeared from the thymus on days 14-21. These data reflect maturational differences between intrathymic and bone marrow precursor cells and suggest different radiosensitivities not linked to proliferative status. The resting state of the thymus immigrants was shown by the absence of Thy-1 acquisition by bone marrow cells continuously labeled for 10 days with BrdUrd in vivo before intrathymic transfer. When such labeled bone marrow cells were injected in the thymus, only the minor BrdUrd- subset gave rise to Thy-1+ cells

Modeling the Effect of Grain Size Mixing on Thermal Inertia Values Derived from Diurnal and Seasonal THEMIS Measurements

Science.gov (United States)

McCarty, C.; Moersch, J.

2017-12-01

Sedimentary processes have slowed over Mars' geologic history. Analysis of the surface today can provide insight into the processes that may have affected it over its history. Sub-resolved checkerboard mixtures of materials with different thermal inertias (and therefore different grain sizes) can lead to differences in thermal inertia values inferred from night and day radiance observations. Information about the grain size distribution of a surface can help determine the degree of sorting it has experienced or it's geologic maturity. Standard methods for deriving thermal inertia from measurements made with THEMIS can give values for the same location that vary by as much as 20% between scenes. Such methods make the assumption that each THEMIS pixel contains material that has uniform thermophysical properties. Here we propose that if a mixture of small and large particles is present within a pixel, the inferred thermal inertia will be strongly dominated by whichever particle is warmer at the time of the measurement because the power radiated by a surface is proportional (by the Stefan-Boltzmann law) to the fourth power of its temperature. This effect will result in a change in thermal inertia values inferred from measurements taken at different times of day and night. Therefore, we expect to see correlation between the magnitude of diurnal variations in inferred thermal inertia values and the degree of grain size mixing for a given pixel location. Preliminary work has shown that the magnitude of such diurnal variation in inferred thermal inertias is sufficient to detect geologically useful differences in grain size distributions. We hypothesize that at least some of the 20% variability in thermal inertias inferred from multiple scenes for a given location could be attributed to sub-pixel grain size mixing rather than uncertainty inherent to the experiment, as previously thought. Mapping the difference in inferred thermal inertias from day and night THEMIS

Effects of ionizing radiation on expression of P21 protein in Jurkat cell line and p21 gene in thymocytes and splenocytes of mice

International Nuclear Information System (INIS)

Ni Guanying; Wu Ning; Guo Haizhuo; Jin Shunzi

2011-01-01

Objective: To investigate the effects of ionizing radiation on the expression of P21 protein in Jurkat cell line and p21 gene in thymocytes and splenocytes of mice. Methods: Flow cytometry (FCM) was used to analyze the expression of P21 protein in Jurkat cells at 12 and 24 h after irradiation to 0, 0.5, 1.0, 2.0, 4.0, and 6.0 Gy. Real-time PCR was used to detect the expression of p21 gene in thymocytes and splenocytes of mice at 4 and 24 h after irradiation to 0, 0.5, 1.0, 2.0, 4.0, and 6.0 Gy. Multi-staining was used to analyze the micronucleus rates of Rct in bone marrow. Results: The expressions of P21 protein were increased in a dose-dependent manner during 0.5-4.0 Gy (t=-24.23 - -3.96, P<0.05), but decreased at 6.0 Gy at 12 and 24 h post-irradiation (t=-11.19, -14.50, P<0.05). The expressions of p21 gene in both thymocytes and splenocytes of mice were increased in dose-dependent manner in the range of 0-6.0 Gy (including 6.0 Gy) (t=-29.96-8.80, P<0.05), and reached to the peak at 6.0 Gy at 4 and 24 h post-irradiation (t=-11.84 - -3.42, P<0.05), except thymocytes at 4 h and 1.0 Gy post-irradiation (t=-3.42, P>0.05). Conclusions: The expressions of P21 protein and p21 gene could be increased by X-ray irradiation, which shows good dose-dependent manners in certain range of dose. (authors)

Radiation effect on the activity of alkaline DNA-ase in rat thymocytes

International Nuclear Information System (INIS)

Ivannik, B.P.; Proskuryakov, S.Ya.; Golubeva, R.V.; Ryabchenko, N.I.

1978-01-01

Using a modified viscosimetric method changes in the activity of alkaline DNAase were registered in thymocytes of irradiated rats. Four hours following irradiation, the activity of alkaline DNAase was 2.17, 3.33 and 4.50 times as high after doses of 500, 900 and 3000 R, respectively. Six hours after exposure the activity was 4.21, 6.18 and 7.83 times as high at doses of 500, 900 and 3000 R, respectively. At a dose of 3000 R, the activity of DNAase was practically invariable during the first three hours after irradiation. After 3 hours, its activity was 1.32 time as high

Novel leukocyte protein, Trojan, differentially expressed during thymocyte development.

Science.gov (United States)

Petrov, Petar; Motobu, Maki; Salmi, Jussi; Uchida, Tatsuya; Vainio, Olli

2010-04-01

"Trojan" is a novel cell surface protein, discovered from chicken embryonic thymocytes on the purpose to identify molecules involved in T cell differentiation. The molecule is predicted as a type I transmembrane protein having a Sushi and two fibronectin type III domains and a pair of intracellular phosphorylation sites. Its transcript expression is specific for lymphoid tissues and the presence of the protein on the surface of recirculating lymphocytes and macrophages was confirmed by immunofluorescence analysis. In thymus, about half of the double negative (CD4(-) CD8(-)) and CD8 single positive and the majority of CD4 single positive cells express Trojan with a relatively high intensity. However, only a minority of the double positive (CD4(+) CD8(+)) cells are positive for Trojan. This expression pattern, similar to that of some proteins with anti-apoptotic and function, like IL-7Ralpha, makes Trojan an attractive candidate of having an anti-apoptotic role. Copyright 2010 Elsevier Ltd. All rights reserved.

Thymic Nurse Cells Participate in Heterotypic Internalization and Repertoire Selection of Immature Thymocytes; Their Removal from the Thymus of Autoimmune Animals May be Important to Disease Etiology.

Science.gov (United States)

Guyden, J C; Martinez, M; Chilukuri, R V E; Reid, V; Kelly, F; Samms, M-O D

2015-01-01

Thymic nurse cells (TNCs) are specialized epithelial cells that reside in the thymic cortex. The initial report of their discovery in 1980 showed TNCs to contain up to 200 thymocytes within specialized vacuoles in their cytoplasm. Much has been reported since that time to determine the function of this heterotypic internalization event that exists between TNCs and developing thymocytes. In this review, we discuss the literature reported that describes the internalization event and the role TNCs play during T cell development in the thymus as well as why these multicellular complexes may be important in inhibiting the development of autoimmune diseases.

Probabilistic resident space object detection using archival THEMIS fluxgate magnetometer data

Science.gov (United States)

Brew, Julian; Holzinger, Marcus J.

2018-05-01

Recent progress in the detection of small space objects, at geosynchronous altitudes, through ground-based optical and radar measurements is demonstrated as a viable method. However, in general, these methods are limited to detection of objects greater than 10 cm. This paper examines the use of magnetometers to detect plausible flyby encounters with charged space objects using a matched filter signal existence binary hypothesis test approach. Relevant data-set processing and reduction of archival fluxgate magnetometer data from the NASA THEMIS mission is discussed in detail. Using the proposed methodology and a false alarm rate of 10%, 285 plausible detections with probability of detection greater than 80% are claimed and several are reviewed in detail.

Effects of tri-n-butyltin chloride on energy metabolism, macromolecular synthesis, precursor uptake and cyclic AMP production in isolated rat thymocytes

NARCIS (Netherlands)

Snoeij, N.J.; Punt, P.M.; Penninks, A.H.; Seinen, W.

1986-01-01

The inhibitor of oxidative phosphorylation tri-n-butyltin chloride (TBTC) causes membrane damage and disintegration of isolated rat thymocytes at concentrations higher than 1 μM. From a concentration of 0.1 μM, TBTC disturbs energy metabolism as indicated by an increase in methylglucose uptake,

Simulation of VLF chorus emissions in the magnetosphere and comparison with THEMIS spacecraft data

Czech Academy of Sciences Publication Activity Database

Demekhov, A. G.; Taubenschuss, Ulrich; Santolík, Ondřej

2017-01-01

Roč. 122, č. 1 (2017), s. 166-184 ISSN 2169-9380 R&D Projects: GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : VLF chorus * THEMIS data * numerical simulations Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.733, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/2016JA023057/full

Semiconservative and unscheduled DNA-synthesis of rat thymocytes under the influence of some radioprotecting and radiosensitizing agents

Energy Technology Data Exchange (ETDEWEB)

Tempel, K.; Wulffius-Kock, M.; Winkle, J.; Schmerold, I.

1982-02-01

The effects of aminoethylisothiuroniumbromide (AET), cysteamine (CY-A), cysteine (CY-E), glutathione (GLU), mercaptoethanol (MA), mercaptopropionylglycine (MPG), N-ethylmaleimide (NEM), metronidazole (MNA), nitroacetophenone (NAP), nitrofurazone (NFA), arabinofuranosylcytosine (araC), fluorouracil (FU), adriamycin (AM), ethidiumbromide (E), bleomycin (BM), and diethyldithiocarbamate (DDC) on the semiconservative and unscheduled incorporation of /sup 3/H-thymidine into the DNA were tested on rat thymocytes in vitro. DNA damage has been measured using the hydroxylapatite system. Unscheduled DNA synthesis was induced by UV-light and/or X-irradiation. The semiconservative DNA synthesis was inhibited by the above substances-with exception of MA and MPG. Aminothioles, NAP, NFA, and BM enhanced, araC, FU, AM, E, and DDC diminished unscheduled DNA synthesis. After alkaline unwinding, the duplex form of DNA decreased under the influence of CY-A, CY-E, GLU, MPG, NEM, NAP, NFA, araC, FU, AM, E, and BM. It is suggested that stimulation of unscheduled DNA synthesis combined with a transient decrease of semiconservative DNA synthesis will amplify the DNA repair capacity of thymocytes, whereas radiation damage may be intensified by araC, FU, AM,E, and DDC - at least partly, through inhibition of unscheduled DNA synthesis. With respect to the action of NAP, NFA, and BM, DNA repair may be concerned in a more indirect manner.

Semiconservative and unscheduled DNA-synthesis of rat thymocytes under the influence of some radioprotecting and radiosensitizing agents

International Nuclear Information System (INIS)

Tempel, K.; Wulffius-Kock, M.; Winkle, J.; Schmerold, I.

1982-01-01

The effects of aminoethylisothiuroniumbromide (AET), cysteamine (CY-A), cysteine (CY-E), glutathione (GLU), mercaptoethanol (MA), mercaptopropionylglycine (MPG), N-ethylmaleimide (NEM), metronidazole (MNA), nitroacetophenone (NAP), nitrofurazone (NFA), arabinofuranosylcytosine (araC), fluorouracil (FU), adriamycin (AM), ethidiumbromide (E), bleomycin (BM), and diethyldithiocarbamate (DDC) on the semiconservative and unscheduled incorporation of 3 H-thymidine into the DNA were tested on rat thymocytes in vitro. DNA damage has been measured using the hydroxylapatite system. Unscheduled DNA synthesis was induced by UV-light and/or X-irradiation. The semiconservative DNA synthesis was inhibited by the above subtrances-with exception of MA and MPG. Aminothioles, NAP, NFA, and BM enhanced, araC, FU, AM, E, and DDC diminished unscheduled DNA synthesis. After alkaline unwinding, the duplex form of DNA decreased under the influence of CY-A, CY-E, GLU, MPG, NEM, NAP, NFA, araC, FU, AM, E, and BM. It is suggested that stimulation of unscheduled DNA synthesis combined with a transient decrease of semiconservative DNA synthesis will amplify the DNA repair capacity of thymocytes, whereas radiation damage may be intensified by araC, FU, AM,E, and DDC - at least partly, through inhibition of unscheduled DNA synthesis. With respect to the action of NAP, NFA, and BM, DNA repair may be concerned in a more indirect manner. (orig.) [de

Linking THEMIS Orbital Data to MSL GTS Measurements: The Thermophysical Properties of the Bagnold Dunes, Mars

Science.gov (United States)

Edwards, C. S.; Piqueux, S.; Hamilton, V. E.; Fergason, R. L.; Herkenhoff, K. E.; Vasavada, A. R.; Sacks, L. E.; Lewis, K. W.; Smith, M. D.

2017-12-01

The surface of Mars has been characterized using orbital thermal infrared observations from the time of the Mariner 9 and Viking missions. More recent observations from missions such as the Thermal Emission Spectrometer onboard the Mars Global Surveyor and the Thermal Emission Imaging System (THEMIS) instrument onboard the 2001 Mars Odyssey orbiter have continued to expand global coverage at progressively higher resolution. THEMIS has been producing 100 m/pixel thermal infrared data with nearly global coverage of the surface for >15 years and has enabled new investigations that successfully link outcrop-scale information to physical properties of the surface. However, significant discrepancies between morphologies and interpreted surface properties derived from orbital thermal measurements remain, requiring a robust link to direct surface measurements. Here, we compare the thermophysical properties and particle sizes derived from the Mars Science Laboratory (MSL) rover's Ground Temperature Sensor (GTS), to those derived orbitally from THEMIS, ultimately linking these measurements to ground truth particle sizes determined from Mars Hand Lens Imager (MAHLI) images. We focus on the relatively homogenous Bagnold dunes, specifically Namib dune, and in general find that all three datasets report consistent particle sizes for the Bagnold dunes ( 110-350 µm, and are within measurement and model uncertainties), indicating that particles sizes of homogeneous materials determined from thermal measurements are reliable. In addition, we assess several potentially significant effects that could influence the derived particle sizes, including: 1) fine-scale (cm-m scale) ripples, and 2) thin (mm-cm) layering of indurated/armored materials. To first order, we find that small scale ripples and thin layers do not significantly affect the determination of bulk thermal inertia determined from orbit. However, a layer of coarser/indurated material and/or fine-scale layering does change

Ceramide synthase 2 facilitates S1P-dependent egress of thymocytes into the circulation in mice.

Science.gov (United States)

Rieck, Michael; Kremser, Christiane; Jobin, Katarzyna; Mettke, Elisabeth; Kurts, Christian; Gräler, Markus; Willecke, Klaus; Kolanus, Waldemar

2017-04-01

Well-defined gradients of the lipid mediator sphingosine-1-phosphate (S1P) direct chemotactic egress of mature thymocytes from the thymus into the circulation. Although it is known that these gradients result from low S1P levels in the thymic parenchyma and high S1P concentrations at the exit sites and in the plasma, the biochemical mechanisms that regulate these differential S1P levels remain unclear. Several studies demonstrated that ceramide synthase 2 (Cers2) regulates the levels of the S1P precursor sphingosine. We, therefore, investigated whether Cers2 is involved in the regulation of S1P gradients and S1P-dependent egress into the circulation. By analyzing Cers2-deficient mice, we demonstrate that Cers2 limits the levels of S1P in thymus and blood to maintain functional S1P gradients that mediate thymocyte emigration into the circulation. This function is specific for Cers2, as we also show that Cers4 is not involved in the regulation of thymic egress. Our study identified Cers2 as an important regulator of S1P-dependent thymic egress, and thus contributes to the understanding of how S1P gradients are maintained in vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Post-irradiation thymocyte regeneration after bone marrow transplantation

International Nuclear Information System (INIS)

Boersma, W.; Betel, I.; Daculsi, R.; Westen, G. van der

1981-01-01

Growth kinetics of the donor-type thymus cell population after transplantation of bone marrow into irradiated syngeneic recipient mice is biphasic. During the first rapid phase of regeneration, lasting until day 19 after transplantation, the rate of development of the donor cells is independent of the number of bone marrow cells inoculated. The second slow phase is observed only when low numbers of bone marrow cells (2.5 x 10 4 ) are transplanted. The decrease in the rate of development is attributed to an efflux of donor cells from the thymus because, at the same time, the first immunologically competent cells are found in spleen. After bone marrow transplantation the regeneration of thymocyte progenitor cells in the marrow is delayed when compared to regeneration of CFUs. Therefore, regenerating marrow has a greatly reduced capacity to restore the thymus cell population. One week after transplantation of 3 x 10 6 cells, 1% of normal capacity of bone marrow is found. It is concluded that the regenerating thymus cells population after bone marrow transplantation is composed of the direct progeny of precursor cells in the inoculum. (author)

The dawn–dusk asymmetry of ion density in the dayside magnetosheath and its annual variability measured by THEMIS

Directory of Open Access Journals (Sweden)

A. P. Dimmock

2016-05-01

Full Text Available The local and global plasma properties in the magnetosheath play a fundamental role in regulating solar wind–magnetosphere coupling processes. However, the magnetosheath is a complex region to characterise as it has been shown theoretically, observationally and through simulations that plasma properties are inhomogeneous, non-isotropic and asymmetric about the Sun-Earth line. To complicate matters, dawn–dusk asymmetries are sensitive to various changes in the upstream conditions on an array of timescales. The present paper focuses exclusively on dawn–dusk asymmetries, in particularly that of ion density. We present a statistical study using THEMIS data of the dawn–dusk asymmetry of ion density in the dayside magnetosheath and its long-term variations between 2009 and 2015. Our data suggest that, in general, the dawn-side densities are higher, and the asymmetry grows from noon towards the terminator. This trend was only observed close to the magnetopause and not in the central magnetosheath. In addition, between 2009 and 2015, the largest asymmetry occurred around 2009 decreasing thereafter. We also concluded that no single parameter such as the Alfvén Mach number, plasma velocity, or the interplanetary magnetic field strength could exclusively account for the observed asymmetry. Interestingly, the dependence on Alfvén Mach number differed between data sets from different time periods. The asymmetry obtained in the THEMIS data set is consistent with previous studies, but the solar cycle dependence was opposite to an analysis based on IMP-8 data. We discuss the physical mechanisms for this asymmetry and its temporal variation. We also put the current results into context with the existing literature in order to relate THEMIS era measurements to those made during earlier solar cycles.

Statistical study of phase relationships between magnetic and plasma thermal pressures in the near-earth magnetosphere using the THEMIS satellites

Science.gov (United States)

Nishi, K.; Kazuo, S.

2017-12-01

The auroral finger-like structures appear in the equatorward part of the auroral oval in the diffuse auroral region, and contribute to the auroral fragmentation into patches during substorm recovery phase. In our previous presentations, we reported the first conjugate observation of auroral finger-like structures using the THEMIS GBO cameras and the THEMIS satellites, which was located at a radial distance of 9 Re in the dawnside plasma sheet. In this conjugate event, we found anti-phase fluctuation of plasma pressure and magnetic pressure with a time scale of 5-20 min in the plasma sheet. This observational fact is consistent with the idea that the finger-like structures are caused by a pressure-driven instability in the balance of plasma and magnetic pressures in the magnetosphere. Then we also searched simultaneous observation events of auroral finger-like structures with the RBSP satellites which have an apogee of 5.8 Re in the inner magnetosphere. Contrary to the first result, the observed variation of plasma and magnetic pressures do not show systematic phase relationship. In order to investigate these phase relationships between plasma and magnetic pressures in the magnetosphere, we statistically analyzed these pressure data using the THEMIS-E satellite for one year in 2011. In the preliminary analysis of pressure variation spectra, we found that out of phase relationship between magnetic and plasma pressures occupied 40 % of the entire period of study. In the presentation, we will discuss these results in the context of relationships between the pressure fluctuations and the magnetospheric instabilities that can cause auroral finger-like structures.

Mechanism of immunotoxicological effects of tributyltin chloride on murine thymocytes.

Science.gov (United States)

Sharma, Neelima; Kumar, Anoop

2014-04-01

Tributyltin-chloride, a well-known organotin compound, is a widespread environmental toxicant. The immunotoxic effects of tributyltin-chloride on mammalian system and its mechanism is still unclear. This study is designed to explore the mode of action of tributyltin-induced apoptosis and other parallel apoptotic pathways in murine thymocytes. The earliest response in oxidative stress followed by mitochondrial membrane depolarization and caspase-3 activation has been observed. Pre-treatment with N-acetyl cysteine and buthionine sulfoximine effectively inhibited the tributyltin-induced apoptotic DNA and elevated the sub G1 population, respectively. Caspase inhibitors pretreatment prevent tributyltin-induced apoptosis. Western blot and flow cytometry indicate no translocation of apoptosis-inducing factor and endonuclease G in the nuclear fraction from mitochondria. Intracellular Ca(2+) levels are significantly raised by tributyltin chloride. These results clearly demonstrate caspase-dependent apoptotic pathway and support the role of oxidative stress, mitochondrial membrane depolarization, caspase-3 activation, and calcium during tributyltin-chloride (TBTC)-induced thymic apoptosis.

Hormonal control of T-cell development in health and disease.

Science.gov (United States)

Savino, Wilson; Mendes-da-Cruz, Daniella Arêas; Lepletier, Ailin; Dardenne, Mireille

2016-02-01

The physiology of the thymus, the primary lymphoid organ in which T cells are generated, is controlled by hormones. Data from animal models indicate that several peptide and nonpeptide hormones act pleiotropically within the thymus to modulate the proliferation, differentiation, migration and death by apoptosis of developing thymocytes. For example, growth hormone and prolactin can enhance thymocyte proliferation and migration, whereas glucocorticoids lead to the apoptosis of these developing cells. The thymus undergoes progressive age-dependent atrophy with a loss of cells being generated and exported, therefore, hormone-based therapies are being developed as an alternative strategy to rejuvenate the organ, as well as to augment thymocyte proliferation and the export of mature T cells to peripheral lymphoid organs. Some hormones (such as growth hormone and progonadoliberin-1) are also being used as therapeutic agents to treat immunodeficiency disorders associated with thymic atrophy, such as HIV infection. In this Review, we discuss the accumulating data that shows the thymus gland is under complex and multifaceted hormonal control that affects the process of T-cell development in health and disease.

Sequential analysis of the virus-immune responder characteristics of thymocytes from F1→parent radiation chimeras

International Nuclear Information System (INIS)

Korngold, R.; Doherty, P.C.

1982-01-01

The virus-immune responder characteristics of thymocytes, spleen and lymph node (LN) cells from (P 1 x P 2 )F 1 →P 1 radiation chimeras have been examined sequentially at weekly intervals. Adoptively-transferred thymocytes generate strong cytotoxic thymus-derived lymphocyte (CTL) responses from 28 to 100 days after reconstitution with bone marrow, which are almost invariably restricted to recognition of virus presented in the context of P 1 . This pattern of H-2 restriction is also maintained for spleen and LN cells from the [(H-2sup(kxd)F 1 →H-2sup(k)] and [(H-2sup(kxb)F 1 →H-2sup(k)] combinations but there is random emergence of reactivity to H-2sup(k)+virus for peripheral lymphoid cells from [(H-2sup(kxb)F 1 →H-2sup(b)] chimeras. Treatment of established [(P 1 xP 2 )]F 1 →P 1 ] chimeras with a low dose of cyclophosphamide (Cy) did not lead to the emergence of significant CTL effector function for P2 + virus. Also, administration of a large dose of Cy prior to irradiation of the chimera recipients did not modify the H-2 restriction profile of the chimera, though the level of CTL responsiveness associated with the appropriate H-2 type was apparently enhanced. (Auth.)

Innate-like CD4 T cells selected by thymocytes suppress adaptive immune responses against bacterial infections

OpenAIRE

Qiao, Yu; Gray, Brian M.; Sofi, Mohammed H.; Bauler, Laura D.; Eaton, Kathryn A.; O'Riordan, Mary X. D.; Chang, Cheong-Hee

2011-01-01

We have reported a new innate-like CD4 T cell population that expresses cell surface makers of effector/memory cells and produce Th1 and Th2 cytokines immediately upon activation. Unlike conventional CD4 T cells that are selected by thymic epithelial cells, these CD4 T cells, named T-CD4 T cells, are selected by MHC class II expressing thymocytes. Previously, we showed that the presence of T-CD4 T cells protected mice from airway inflammation suggesting an immune regulatory role of T-CD4 T ce...

Global distribution of bedrock exposures on Mars using THEMIS high-resolution thermal inertia

Science.gov (United States)

Edwards, C.S.; Bandfield, J.L.; Christensen, P.R.; Fergason, R.L.

2009-01-01

We investigate high thermal inertia surfaces using the Mars Odyssey Thermal Emission Imaging System (THEMIS) nighttime temperature images (100 m/pixel spatial sampling). For this study, we interpret any pixel in a THEMIS image with a thermal inertia over 1200 J m-2 K-1 s-1/2 as "bedrock" which represents either in situ rock exposures or rock-dominated surfaces. Three distinct morphologies, ranked from most to least common, are associated with these high thermal inertia surfaces: (1) valley and crater walls associated with mass wasting and high surface slope angles; (2) floors of craters with diameters >25 km and containing melt or volcanics associated with larger, high-energy impacts; and (3) intercrater surfaces with compositions significantly more mafic than the surrounding regolith. In general, bedrock instances on Mars occur as small exposures (less than several square kilometers) situated in lower-albedo (inertia (>350 J m-2 K-1 s-1/2), and relatively dust-free (dust cover index <0.95) regions; however, there are instances that do not follow these generalizations. Most instances are concentrated in the southern highlands, with very few located at high latitudes (poleward of 45oN and 58oS), suggesting enhanced mechanical breakdown probably associated with permafrost. Overall, Mars has very little exposed bedrock with only 960 instances identified from 75oS to 75oN with likely <3500 km2 exposed, representing???1% of the total surface area. These data indicate that Mars has likely undergone large-scale surface processing and reworking, both chemically and mechanically, either destroying or masking a majority of the bedrock exposures on the planet. Copyright 2009 by the American Geophysical Union.

Multi-point observations of large-amplitude electric fields during substorms obtained by THEMIS

Science.gov (United States)

Ogasawara, K.; Kasaba, Y.; Nishimura, Y.; Hori, T.; Takada, T.; Miyashita, Y.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.

2009-12-01

Large-amplitude electric fields over 100 mV/m have been observed around the equatorial magnetosphere. These electric fields may contribute to energy transport and particle acceleration in the magnetosphere [e.g., Wygant et al., 2000, 2002], and seem to be related to fast plasma flows with a size of a few Re [Nakamura et al., 2001]. In order to understand their macroscopic characteristics and the effects to magnetic activities, it is important to observe both fields and particles simultaneously at multiple locations within several Re. Five THEMIS probes can frequently provide such chances. In this paper, we show the several events with large-amplitude electric fields during substorms obtained by THEMIS. One of the events is found in 05:50-06:00 UT on 11 March 2008, when TH-D (Xsm=-10.7 Re, Ysm=4.8 Re) and TH-E (Xsm=-10.3 Re, Ysm=5.6 Re) observed intense electric fields. At 05:54 UT, THEMIS GBO-s clearly showed the auroral onset signature. The great intensification was near the SNKQ station, and this structure moved westward with the speed of ~6 km/s. It corresponds to ~200 km/s, as mapped to the TH-D/E location. The footprints of TH-A (Xsm=-6.8 Re, Ysm=-0.4 Re), D, and E were close to the site of the aurora. The location of TH-D was beside that of TH-E, and TH-A was located earthward and eastward from the former two. The enhanced electric fields observed by TH-D and E were associated with magnetic dipolarization and earthward high-speed plasma flow. They were also associated with the depletion of electron density estimated by the spacecraft potential. These features are consistent with the model of plasma bubbles [e.g., Pontius and Wolf, 1990]. The Y components of plasma flows were 200-300 km/s, roughly consistent with the westward auroral motion as mapped to the equatorial magnetosphere. Also, we found that Poynting flux of low frequency was efficient to illuminate the auroral emissions. This fact suggests that electromagnetic energy is transported to the

La edad de las familias Eos, Themis y Koronis

Science.gov (United States)

Gil-Hutton, R.

Las familias de asteroides son el producto de la disrupción colisional de objetos destruídos por impactos ocurridos en el cinturón principal. Las colisiones posteriores han modificado los tamaños y las órbitas de los miembros de estas familias, por lo que las distribuciones que vemos hoy en día pueden ser muy diferentes de aquellas producidas inmediatamente después de la fragmentación del objeto original. En esta hipótesis, puede ser difícil reconstruir la evolución colisional de la familia basándose sólo en las actuales distribuciones y puede ser necesario hacer ciertas suposiciones para obtener información sobre las condiciones iniciales. En este trabajo se deriva una estimación de la edad de las familias Eos, Themis y Koronis obtenida de una simulación de la evolución colisional de un cuerpo original teórico para cada familia usando un modelo de distribución para el cinturón propuesto por Gil-Hutton (1996).

Phenotypic and functional properties of murine thymocytes. II. Quantitation of host- and donor-derived cytolytic T lymphocyte precursors in regenerating radiation bone marrow chimeras

International Nuclear Information System (INIS)

Ceredig, R.; McDonald, H.R.

1982-01-01

Thymocytes from radiation bone marrow chimeras, in which donor bone marrow and irradiated recipient differed at the Thy-1 locus, were stained by indirect immunofluorescence with monoclonal anti-Thy-1 antibodies and analyzed by flow microfluorometry (FMF). Kinetic studies indicated an early appearance of host-derived (CBA, Thy-1.2 + ) thymocytes, which reaches maximum number of 10 to 20 x 10 6 cells at 12 to 16 days after bone marrow reconstitution. Donor-derived (AKR, Thy-1.1 + ) cells were not detectable until 10 to 12 days after reconstitution; subsequently, they increased exponentially in number until 28 days, when they accounted for essentially all cells in the thymus (50 x 10 6 ). Concomitant with the appearance and disappearance of host-derived cells was a change in their Thy-1 surface phenotype. In particular, the proportion of host cells having a ''mature'' phenotype (weakly Thy-1.2 staining) increased progressively with time after irradiation. Functional studies using a sensitive mixed leukocyte microculture system to quantitate cytolytic T lymphocyte precursors (CTL-P) were also carried out in regenerating chimeric thymuses. Initially, the regenerating thymus contained few CTL-P, but by 4 wk after reconstitution, frequencies similar to control adult thymuses were obtained. Analysis of the CTL-P content of host and donor-derived subpopulations, separated either by appropriate anti-Thy-1 antibody plus complement or by direct cell sorting, indicated that both host- and donor-derived cells contained appreciable numbers of CTL-P. Furthermore, increases in CTL-P frequency of both host and donor subpopulations correlated with changes in their surface Thy-1 phenotype

Atypical pit craters on Mars: new insights from THEMIS, CTX and HiRISE observations

Science.gov (United States)

Cushing, Glen; Okubo, Chris H.; Titus, Timothy N.

2015-01-01

More than 100 pit craters in the Tharsis region of Mars exhibit morphologies, diameters and thermal behaviors that diverge from the much larger bowl-shaped pit craters that occur in most regions across Mars. These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50-350 m, and high depth-to-diameter (d/D) ratios that are usually greater than 0.3 (which is an upper-range value for impacts and bowl-shaped pit craters), and can exceed values of 1.8. Observations by the Mars Odyssey THermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night, and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters. Kīlauea volcano, Hawai'i, hosts pit craters that formed through subsurface collapse into active volcanic dikes, resulting in pits that can appear morphologically analogous to either APCs or bowl-shaped pit craters. Partially-drained dikes are sometimes exposed within the lower walls and floors of these terrestrial APC analogs and can form extensive cave systems with unique microclimates. Similar caves in martian pit craters are of great interest for astrobiology. This study uses new observations by the Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX) to refine previous work where seven APCs were described from lower-resolution THEMIS visible-wavelength (VIS) observations. Here, we identify locations of 115 APCs, map their distribution across the Tharsis region, characterize their internal morphologies with high-resolution observations, and discuss possible formation mechanisms.

Alternative pathway for the development of Vα14+ NKT cells directly from CD4-CD8- thymocytes that bypasses the CD4+CD8+ stage.

Science.gov (United States)

Dashtsoodol, Nyambayar; Shigeura, Tomokuni; Aihara, Minako; Ozawa, Ritsuko; Kojo, Satoshi; Harada, Michishige; Endo, Takaho A; Watanabe, Takashi; Ohara, Osamu; Taniguchi, Masaru

2017-03-01

Although invariant V α 14 + natural killer T cells (NKT cells) are thought to be generated from CD4 + CD8 + double-positive (DP) thymocytes, the developmental origin of CD4 - CD8 - double-negative (DN) NKT cells still remains unresolved. Here we provide definitive genetic evidence obtained, through studies of mice with DP-stage-specific ablation of expression of the gene encoding the recombinase component RAG-2 (Rag2) and by a fate-mapping approach, that supports the proposal of the existence of an alternative developmental pathway through which a fraction of DN NKT cells with strong T-helper-type-1 (T H 1)-biased and cytotoxic characteristics develop from late DN-stage thymocytes, bypassing the DP stage. These findings provide new insight into understanding of the development of NKT cells and propose a role for timing of expression of the invariant T cell antigen receptor in determining the functional properties of NKT cells.

Phenotypic and functional properties of murine thymocytes. II. Quantitation of host- and donor-derived cytolytic T lymphocyte precursors in regenerating radiation bone marrow chimeras

Energy Technology Data Exchange (ETDEWEB)

Ceredig, R.; McDonald, H.R.

1982-02-01

Thymocytes from radiation bone marrow chimeras, in which donor bone marrow and irradiated recipient differed at the Thy-1 locus, were stained by indirect immunofluorescence with monoclonal anti-Thy-1 antibodies and analyzed by flow microfluorometry (FMF). Kinetic studies indicated an early appearance of host-derived (CBA, Thy-1.2/sup +/) thymocytes, which reaches maximum number of 10 to 20 x 10/sup 6/ cells at 12 to 16 days after bone marrow reconstitution. Donor-derived (AKR, Thy-1.1/sup +/) cells were not detectable until 10 to 12 days after reconstitution; subsequently, they increased exponentially in number until 28 days, when they accounted for essentially all cells in the thymus (50 x 10/sup 6/). Concomitant with the appearance and disappearance of host-derived cells was a change in their Thy-1 surface phenotype. In particular, the proportion of host cells having a ''mature'' phenotype (weakly Thy-1.2 staining) increased progressively with time after irradiation. Functional studies using a sensitive mixed leukocyte microculture system to quantitate cytolytic T lymphocyte precursors (CTL-P) were also carried out in regenerating chimeric thymuses. Initially, the regenerating thymus contained few CTL-P, but by 4 wk after reconstitution, frequencies similar to control adult thymuses were obtained. Analysis of the CTL-P content of host and donor-derived subpopulations, separated either by appropriate anti-Thy-1 antibody plus complement or by direct cell sorting, indicated that both host- and donor-derived cells contained appreciable numbers of CTL-P. Furthermore, increases in CTL-P frequency of both host and donor subpopulations correlated with changes in their surface Thy-1 phenotype.

Expression of antigens coded in murine leukemia viruses on thymocytes of allogeneic donor origin in AKR mice following syngeneic or allogeneic bone marrow transplantation

International Nuclear Information System (INIS)

Wustrow, T.P.; Good, R.A.

1985-01-01

Removal of T-lymphocytes from marrow inoculum with monoclonal antibody plus complement permitted establishment of long-lived allogeneic chimeras between C57BL/6 and AKR/J mice. Development of leukemia was prevented for 15 mo. Protection from leukemia occurred with both young (4 wk) and older (4 mo) recipients. AKR mice reconstituted with syngeneic marrow or control AKR mice all developed leukemia-lymphoma before 1 yr of age. During spontaneous lymphomagenesis in AKR mice, amplified expression of gag or env gene-coded virus antigens on the surface of thymocytes preceded leukemia development and evidence for amplification of other virus genes. These changes generally appeared before 6 mo. Similar viral gene expression and viral gene amplification occurred in the thymus and spleen cells of leukemia-resistant chimeric mice. Using monoclonal antibodies to Mr 70,000 glycoprotein epitopes characteristic of ecotropic, xenotropic, or dualtropic viruses, antigens marking each virus form were found on thymocytes of allogeneic 4-wk and 4-mo chimeras as well as on the cells of AKR mice and of AKR mice reconstituted with syngeneic marrow. Flow cytometric analysis showed amplification of the virus genes in mice protected from leukemia-lymphoma by allogeneic bone marrow transplantation from leukemia-resistant mice. Allogeneic chimeras and syngeneically transplanted mice both showed evidence of accelerated viremia and of recombinant virus formation. The findings suggest that an event essential to leukemogenesis which occurs within the AKR lymphoid cells or their environment is lacking in the allogeneic chimeras. The nature of this influence of a resistance gene or genes introduced into AKR mice by allogeneic bone marrow transplantation deserves further study

Van Allen Probes, THEMIS, GOES, and Cluster Observations of EMIC Waves, ULF Pulsations, and an Electron Flux Dropout

Science.gov (United States)

Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; Macdowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.;

The influence of blood plasma of irradiated animals on activity of Ca2+ - ATPase and Mg2+ - ATPase in plasma membrane of thymocytes

International Nuclear Information System (INIS)

Dreval', V.I.

1994-01-01

Rats were irradiated at doses 1.5, 4.0, 7.0 and 10 Gy. After 1, 8, 15, 22 and 30 days the effect of blood plasma on activity of Ca 2+ -ATPase and Mg 2+ -ATPase in plasma membrane of thymocytes was investigated. It was found that the raise of irradiation dose leads to increasing of blood plasma effect on membrane-bound enzymes

Requirement of mitoses for the reversal of X-inactivation in cell hybrids between murine embryonal carcinoma cells and normal female thymocytes

International Nuclear Information System (INIS)

Takagi, N.

1988-01-01

By means of a 5-bromodeoxyuridine (BrdU) incorporation and acridine orange fluorescence staining method the authors studied reactivation of the inactivated X chromosome (X i ) in newly formed cell hybrids between the near-diploid HPRT-deficient OTF9-63 murine embryonal carcinoma cell (ECC) with an XO sex chromosome constitution and the normal female mouse thymocyte. Synchronization of the late replicating S chromosome in such hybrid cells, indicative of reactivation, was found for the first time on Day 3, and the frequency of reactivation was attained 90% on Day 5. Inhibition of cell cycle progression either by methylglyoxal bis(guanylhydrazone) dihydrochloride, an inhibitor of polyamine metabolism, or by isoleucine-deficient medium after cell fusion delayed reactivation of the X i , which implied that the number of cell division cycles traversed by individual cells rather than the length of time after cell fusion is critical for the reactivation. Double-labeling experiments using [ 3 H]thymidine and BrdU indicated that hybrid cells had undergone three or four mitoses before reactivation of the X i . Most probably reactivation of the X i is consequent to reversion of the thymocyte genome to an undifferentiated state under the influence of OTF9 genome. DNA demethylation or dilution of X i -specific factors by mitoses may be involved in this process

Requirement of mitoses for the reversal of X-inactivation in cell hybrids between murine embryonal carcinoma cells and normal female thymocytes

Energy Technology Data Exchange (ETDEWEB)

Takagi, N. (Hokkaido Univ., Sapporo (Japan))

1988-04-01

By means of a 5-bromodeoxyuridine (BrdU) incorporation and acridine orange fluorescence staining method the authors studied reactivation of the inactivated X chromosome (X{sub i}) in newly formed cell hybrids between the near-diploid HPRT-deficient OTF9-63 murine embryonal carcinoma cell (ECC) with an XO sex chromosome constitution and the normal female mouse thymocyte. Synchronization of the late replicating S chromosome in such hybrid cells, indicative of reactivation, was found for the first time on Day 3, and the frequency of reactivation was attained 90% on Day 5. Inhibition of cell cycle progression either by methylglyoxal bis(guanylhydrazone) dihydrochloride, an inhibitor of polyamine metabolism, or by isoleucine-deficient medium after cell fusion delayed reactivation of the X{sub i}, which implied that the number of cell division cycles traversed by individual cells rather than the length of time after cell fusion is critical for the reactivation. Double-labeling experiments using ({sup 3}H)thymidine and BrdU indicated that hybrid cells had undergone three or four mitoses before reactivation of the X{sub i}. Most probably reactivation of the X{sub i} is consequent to reversion of the thymocyte genome to an undifferentiated state under the influence of OTF9 genome. DNA demethylation or dilution of X{sub i}-specific factors by mitoses may be involved in this process.

Ion hole formation and nonlinear generation of electromagnetic ion cyclotron waves: THEMIS observations

Science.gov (United States)

Shoji, Masafumi; Miyoshi, Yoshizumi; Katoh, Yuto; Keika, Kunihiro; Angelopoulos, Vassilis; Kasahara, Satoshi; Asamura, Kazushi; Nakamura, Satoko; Omura, Yoshiharu

2017-09-01

Electromagnetic plasma waves are thought to be responsible for energy exchange between charged particles in space plasmas. Such an energy exchange process is evidenced by phase space holes identified in the ion distribution function and measurements of the dot product of the plasma wave electric field and the ion velocity. We develop a method to identify ion hole formation, taking into consideration the phase differences between the gyromotion of ions and the electromagnetic ion cyclotron (EMIC) waves. Using this method, we identify ion holes in the distribution function and the resulting nonlinear EMIC wave evolution from Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations. These ion holes are key to wave growth and frequency drift by the ion currents through nonlinear wave-particle interactions, which are identified by a computer simulation in this study.

Van Allen Probes, THEMIS, GOES, and Cluster Observations of EMIC Waves, ULF Pulsations, and an Electron Flux Dropout

Science.gov (United States)

Sigsbee, K.; Kletzing, C. A.; Smith, C. W.; Macdowall, R.; Spence, H.; Reeves, G.; Blake, J. B.; Baker, D. N.; Green, J. C.; Singer, H. J.;

Metabolism of neutral lipids in nuclei and chromatin of thymocytes from normal and γ-irradiated rats

International Nuclear Information System (INIS)

Kulagina, T.P.; Shuruta, S.A.; Kolomijtseva, I.K.

1993-01-01

The levels ans specific radioactivities of cholesterol and free fatty acids in nuclei and chromatin of thymocytes from normal and γ-irradiated (10 Gy) rats have been studied. The radioactivity of the total lipid fraction of γ-irradiated cells was decreased significantly in the absence of inhibition of [2- 14 C]acetete incorporation into the total proteil and lipid reactions and the [ 3 H]uracyl incorporation into the acid-insoluble RNA. The concentration of free fatty acids in the nuclei increased significantly after irradiation. The specific radioactivity of cholesterol in chromatin was higher than in the nuclei. The differences in specific radioactivities of free fatty acids were less pronounced. After irradiation the ratio of specific radioactivities of free fatty acids in chromatin to that in the nucleai showed a tendency to increase

Inhibiting the repair of DNA damage induced by gamma irradiation in rat thymocytes

International Nuclear Information System (INIS)

Smit, J.A.; Stark, J.H.

1994-01-01

This study assessed the ability of 11 established and potential radiosensitizing agents to retard the repair of radiation-induced DNA damage with a view to enhancing the immunosuppressive effects of in vivo lymphoid irradiation. The capability of irradiated rat thymocytes to repair DNA damage was assessed by an adaptation of the fluorimetric unwinding method. Three compounds, 3-aminobenzamide (3-AB), novobiocin and flavone-8-acetic acid (FAA), inhibited repair significantly. We also report the effect of low-dose irradiation combined with repair inhibitors on the relationship between DNA strand breaks, fragmentation, cell viability and use of nicotinamide adenine dinucleotide (NAD). DNA fragmentation was increased by 1 mM/l FAA, 1 mM/l novobiocin and 50 μM/l RS-61443 within 3 h of incubation. The latter two compounds also proved cytotoxic. All three drugs augmented the effect of ionizing radiation on the use of NAD. Of the agents investigated, FAA showed the most promise for augmenting the immunosuppressive action of irradiation at nontoxic, pharmacokinetically achievable concentrations. 33 refs., 1 fig., 2 tabs

Immune reconstitution with two different rabbit polyclonal anti-thymocytes globulins.

Science.gov (United States)

Bamoulid, Jamal; Crepin, Thomas; Gaiffe, Emilie; Laheurte, Caroline; Moulin, Bruno; Frimat, Luc; Rieu, Philippe; Mousson, Christiane; Durrbach, Antoine; Heng, Anne-Elisabeth; Rebibou, Jean-Michel; Saas, Philippe; Courivaud, Cécile; Ducloux, Didier

2017-12-01

Broad T cell depletion by polyclonal anti-thymocyte globulins (ATG) has been used for many years as a part of immunosuppressive treatment in transplantation. Currently, two different ATG are used in clinical practice, Thymoglobulin and Grafalon. Due to differences in the immunization source, these products contain different specificities and quantity of antibodies. These differences may have clinical consequences. We conducted a nested study in a large prospective multicentric cohort of kidney transplant to determine whether Grafalon-treated and Thymoglobulin-treated patients experience different lymphocyte reconstitution and clinical outcomes. 182 patients matched for age, gender, CMV status, CMV prophylaxis, number of previous transplantation, and maintenance immunosuppressive treatment were included (Thymoglobulin, [n=91]; Grafalon®, [n=91]). One-year post-transplant, recent thymic emigrants were significantly decreased (12±10% vs 21±12%; p<0.001) in Grafalon-treated patients. By contrast, T cell activation (CD38+DR+Ki67+) and senescence (CD8+CD57+CD28-) was increased in Thymoglobulin-treated patients. Compared to Grafalon, Thymoglobulin was not associated with a significantly different rate of acute rejection. CMV disease (p=0.013) was more frequent in Thymoglobulin-treated patients. Grafalon and Thymoglobulin seem to be equivalent to prevent acute rejection. CMV disease is more frequent in Thymoglobulin-treated patients. One year post-transplant immune profile profoundly differs according to the type of ATG. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of gamma-radiation on direct intercellular interaction (rosette formation) between thymus macrophages and thymocytes

International Nuclear Information System (INIS)

Belyakov, I.M.; Yarilin, A.A.

1992-01-01

In experiments with mice, the effect of radiation on resette formation between thymus macrophages (Th-MPh) and thymocytes (Thc) was studied on days 1, 4, 12, 30, and 60 following gamma-irradiation with doses of 0.5, 2, 4, and 8 Gy. gamma-Irradiation with doses of above 2 Gy was shown to cause a dose-dependent inhibition of rosette formation of Th-MPh with Thc in vitro. Two types of rosette-forming Th-MPh were identified: RFMPhII with low rate of binding to Thc and RFMPhII with high rate of binding to Thc. Radiation affects mainly the RFMPhII content. The total population of rosette-forming Th-MPh was restored on day 60 mainly due to cells with low rate of rosette formation. The EC supernatant promoted rosette formation of exposed Th-MPh with Thc. The effect was maximum at early times following irradiation of Th-MPh with a dose of 4 Gy

Supra Arcade Downflows with XRT Informed by Dipolarization Fronts with THEMIS

Science.gov (United States)

Kobelski, Adam; Savage, Sabrina L.; Malaspina, David M.

2016-01-01

Magnetic reconnection can rapidly reconfigure the magnetic field of the corona, accelerating plasma through the site of reconnection. Ambiguities due to the nature of remote sensing have complicated the interpretation of observations of the inflowing and outflowing plasma in reconnecting regions. In particular, the interpretation of sunward moving density depletions above flare arcades (known as Supra Arcade Downflows - SADs) is still debated. Hinode/XRT has provided a wealth of observations for SADs and helped inform our current understanding of these structures. SADs have been interpreted as wakes behind newly reconnected and outflowing loops (Supra Arcade Downflowing Loops - SADLs). Models have shown the plausibility of this interpretation, though this interpretation has not yet been fully accepted. We present here observations of newly reconnected outflowing loops observed via in situ instruments in the magnetosphere. These observations, provided by five THEMIS spacecraft, show that around retracting loops (dipolarization fronts in this context) similar dynamic temperature and density structures are found as seen in SADs. We compare data from multiple SADs and dipolarization fronts to show that the observational signatures implied in the corona can be directly observed in similar plasma regimes in the magnetosphere, strongly favoring the interpretation of SADs as wakes behind retracting loops.

Intermittent Anisotropic Turbulence Detected by THEMIS in the Magnetosheath

Science.gov (United States)

Macek, W. M.; Wawrzaszek, A.; Kucharuk, B.; Sibeck, D. G.

2017-12-01

Following our previous study of Time History of Events and Macroscale Interactions during Substorms (THEMIS) data, we consider intermittent turbulence in the magnetosheath depending on various conditions of the magnetized plasma behind the Earth’s bow shock and now also near the magnetopause. Namely, we look at the fluctuations of the components of the Elsässer variables in the plane perpendicular to the scale-dependent background magnetic fields and along the local average ambient magnetic fields. We have shown that Alfvén fluctuations often exhibit strong anisotropic non-gyrotropic turbulent intermittent behavior resulting in substantial deviations of the probability density functions from a normal Gaussian distribution with a large kurtosis. In particular, for very high Alfvénic Mach numbers and high plasma beta, we have clear anisotropy with non-Gaussian statistics in the transverse directions. However, along the magnetic field, the kurtosis is small and the plasma is close to equilibrium. On the other hand, intermittency becomes weaker for moderate Alfvén Mach numbers and lower values of the plasma parameter beta. It also seems that the degree of intermittency of turbulence for the outgoing fluctuations propagating relative to the ambient magnetic field is usually similar as for the ingoing fluctuations, which is in agreement with approximate equipartition of energy between these oppositely propagating Alfvén waves. We believe that the different characteristics of this intermittent anisotropic turbulent behavior in various regions of space and astrophysical plasmas can help identify nonlinear structures responsible for deviations of the plasma from equilibrium.

Exposure of tumor-bearing mice to extremely high-frequency electromagnetic radiation modifies the composition of fatty acids in thymocytes and tumor tissue.

Science.gov (United States)

Gapeyev, Andrew B; Kulagina, Tatiana P; Aripovsky, Alexander V

2013-08-01

To test the participation of fatty acids (FA) in antitumor effects of extremely high-frequency electromagnetic radiation (EHF EMR), the changes in the FA composition in the thymus, liver, blood plasma, muscle tissue, and tumor tissue in mice with Ehrlich solid carcinoma exposed to EHF EMR were studied. Normal and tumor-bearing mice were exposed to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm2, 20 min daily during five consecutive days beginning the first day after the inoculation of tumor cells). Fatty acid composition of various organs and tissues of mice were determined using a gas chromatography. It was shown that the exposure of normal mice to EHF EMR or tumor growth significantly increased the content of monounsaturated FA (MUFA) and decreased the content of polyunsaturated FA (PUFA) in all tissues examined. Exposure of tumor-bearing mice to EHF EMR led to the recovery of FA composition in thymocytes to the state that is typical for normal animals. In other tissues of tumor-bearing mice, the exposure to EHF EMR did not induce considerable changes that would be significantly distinguished between disturbances caused by EHF EMR exposure or tumor growth separately. In tumor tissue which is characterized by elevated level of MUFA, the exposure to EHF EMR significantly decreased the summary content of MUFA and increased the summary content of PUFA. The recovery of the FA composition in thymocytes and the modification of the FA composition in the tumor under the influence of EHF EMR on tumor-bearing animals may have crucial importance for elucidating the mechanisms of antitumor effects of the electromagnetic radiation.

Deregulation of mTOR signaling is involved in thymic lymphoma development in Atm-/- mice

International Nuclear Information System (INIS)

Kuang, Xianghong; Shen, Jianjun; Wong, Paul K.Y.; Yan, Mingshan

2009-01-01

Abnormal thymocyte development with thymic lymphomagenesis inevitably occurs in Atm-/- mice, indicating that ATM plays a pivotal role in regulating postnatal thymocyte development and preventing thymic lymphomagenesis. The mechanism for ATM controls these processes is unclear. We have shown previously that c-Myc, an oncoprotein regulated by the mammalian target of rapamycin (mTOR), is overexpressed in Atm-/- thymocytes. Here, we show that inhibition of mTOR signaling with its specific inhibitor, rapamycin, suppresses normal thymocyte DNA synthesis by downregulating 4EBP1, but not S6K, and that 4EBP1 phosphorylation and cyclin D1 expression are coordinately increased in Atm-/- thymocytes. Administration of rapamycin to Atm-/- mice attenuates elevated phospho-4EBP1, c-Myc and cyclin D1 in their thymocytes, and delays thymic lymphoma development. These results indicate that mTOR downstream effector 4EBP1 is essential for normal thymocyte proliferation, but deregulation of 4EBP1 in Atm deficiency is a major factor driving thymic lymphomagenesis in the animals.

Effect of some radioprotective and radiosensitizing substances on the semiconservative and unscheduled DNA biosynthesis of rat thymocytes

International Nuclear Information System (INIS)

Winkle, J.

1981-01-01

The effect on the semiconservative and unscheduled insertion of 3 H-methyl-thymidine (TdR- 3 H) into the DNA was tested on rat thymocytes in vitro. The semiconservative incorporation of TdR- 3 H was inhibited by AET, cysteine glutathione, N-ethylmaleimide, cytosine arabinoside, ethidiumbromide, bleomycin and diethyldithiocarbamate. Metronidazole and caffeine had no effect. Aminothiols and bleomycin stimulated, cytosine arabinoside, N-ethylmaleimide, ethidiumbromide and diethyldithiocarbamate decreased the unscheduled TdR- 3 H incorporation. There was no substantial effect of an exposure to UV-rays. The results lead to the following conclusions: The aminothiol-effect on the excision repair suggest that inhibition of the semiconservative DNA-synthesis will amplify regenerative capacity of the cells. The effect of most substances investigated accord with the present views on their mechanisms of action. The present investigations do not allow an explanation of the influence of diethyldithiocarbamate unspecific effects (such as complexing activity) and more specialized reactions (such as inhibition of superoxide dismutase) must be kept in mind. (orig./MG)

Compositions of Bedrock Containing Craters on Mars as Viewed by TES, THEMIS, and CRISM

Science.gov (United States)

Edwards, C. S.; Rogers, D.; Bandfield, J. L.; Christensen, P. R.

2009-12-01

An investigation of Martian high thermal inertia crater surfaces has been made using derived THEMIS thermal inertia data. High thermal inertia surfaces or interpreted bedrock are defined as any pixel in a THEMIS image with a thermal inertia over 1200 J K-1m-2s-1/2 and may refer to in situ rock exposures or rock-dominated surfaces. While three different surface morphologies (valley and crater walls, crater floors, and plains surface) were originally identified [Edwards et al., in press], the focus of this study is to better characterize the compositional, thermophysical, and geological characteristics of the crater floors surface. These surfaces may be related to impact-associated volcanism that often occurs in conjunction with large energetic impacts. These craters are commonly modified, lack a central peak, have shallow sloped walls, and little to no visible ejecta, indicating the relatively old ages of these impacts. They are generally large, ranging in size from 18.5 to 179km in diameter, with an average of ~52km [Edwards et al., in press]. Boulders are also observed in high-resolution imagery (e.g. HiRISE) along with fine scale randomly oriented cracks and fractures. TES spectra for ~60 of the 92 originally identified sites have been examined in detail and can be broken down into two distinctive spectral groups, olivine bearing (~80%, with >10% olivine and often >20%) and non-olivine bearing craters (~20%, with inertia crater floors. In this case, magma is likely derived from decompression melting of the mantle due to the removal of overlying material. This magma reaches the surface through fractures and cracks in the basement rock likely caused by the impact event. This is consistent with the observed compositions, as material derived directly from the Martian mantle is expected to be significantly more mafic than the surrounding country rock. These sites are likely locations where the some of the most primitive material on Mars is observed and can be used to

Anti-apoptotic effect of hyperglycemia can allow survival of potentially autoreactive T cells.

Science.gov (United States)

Ramakrishnan, P; Kahn, D A; Baltimore, D

2011-04-01

Thymocyte development is a tightly controlled multi-step process involving selective elimination of self-reactive and non-functional T cells by apoptosis. This developmental process depends on signaling by Notch, IL-7 and active glucose metabolism. In this study, we explored the requirement of glucose for thymocyte survival and found that in addition to metabolic regulation, glucose leads to the expression of anti-apoptotic genes. Under hyperglycemic conditions, both mouse and human thymocytes demonstrate enhanced survival. We show that glucose-induced anti-apoptotic genes are dependent on NF-κB p65 because high glucose is unable to attenuate normal ongoing apoptosis of thymocytes isolated from p65 knockout mice. Furthermore, we demonstrate that in vivo hyperglycemia decreases apoptosis of thymocytes allowing for survival of potentially self-reactive thymocytes. These results imply that hyperglycemic conditions could contribute to the development of autoimmunity through dysregulated thymic selection. © 2011 Macmillan Publishers Limited

Quasi-parallel whistler mode waves observed by THEMIS during near-earth dipolarizations

Science.gov (United States)

Le Contel, O.; Roux, A.; Jacquey, C.; Robert, P.; Berthomier, M.; Chust, T.; Grison, B.; Angelopoulos, V.; Sibeck, D.; Chaston, C. C.; Cully, C. M.; Ergun, B.; Glassmeier, K.-H.; Auster, U.; McFadden, J.; Carlson, C.; Larson, D.; Bonnell, J. W.; Mende, S.; Russell, C. T.; Donovan, E.; Mann, I.; Singer, H.

2009-06-01

We report on quasi-parallel whistler emissions detected by the near-earth satellites of the THEMIS mission before, during, and after local dipolarization. These emissions are associated with an electron temperature anisotropy α=T⊥e/T||e>1 consistent with the linear theory of whistler mode anisotropy instability. When the whistler mode emissions are observed the measured electron anisotropy varies inversely with β||e (the ratio of the electron parallel pressure to the magnetic pressure) as predicted by Gary and Wang (1996). Narrow band whistler emissions correspond to the small α existing before dipolarization whereas the broad band emissions correspond to large α observed during and after dipolarization. The energy in the whistler mode is leaving the current sheet and is propagating along the background magnetic field, towards the Earth. A simple time-independent description based on the Liouville's theorem indicates that the electron temperature anisotropy decreases with the distance along the magnetic field from the equator. Once this variation of α is taken into account, the linear theory predicts an equatorial origin for the whistler mode. The linear theory is also consistent with the observed bandwidth of wave emissions. Yet, the anisotropy required to be fully consistent with the observations is somewhat larger than the measured one. Although the discrepancy remains within the instrumental error bars, this could be due to time-dependent effects which have been neglected. The possible role of the whistler waves in the substorm process is discussed.

Quasi-parallel whistler mode waves observed by THEMIS during near-earth dipolarizations

Directory of Open Access Journals (Sweden)

O. Le Contel

2009-06-01

Full Text Available We report on quasi-parallel whistler emissions detected by the near-earth satellites of the THEMIS mission before, during, and after local dipolarization. These emissions are associated with an electron temperature anisotropy α=T⊥e/T||e>1 consistent with the linear theory of whistler mode anisotropy instability. When the whistler mode emissions are observed the measured electron anisotropy varies inversely with β||e (the ratio of the electron parallel pressure to the magnetic pressure as predicted by Gary and Wang (1996. Narrow band whistler emissions correspond to the small α existing before dipolarization whereas the broad band emissions correspond to large α observed during and after dipolarization. The energy in the whistler mode is leaving the current sheet and is propagating along the background magnetic field, towards the Earth. A simple time-independent description based on the Liouville's theorem indicates that the electron temperature anisotropy decreases with the distance along the magnetic field from the equator. Once this variation of α is taken into account, the linear theory predicts an equatorial origin for the whistler mode. The linear theory is also consistent with the observed bandwidth of wave emissions. Yet, the anisotropy required to be fully consistent with the observations is somewhat larger than the measured one. Although the discrepancy remains within the instrumental error bars, this could be due to time-dependent effects which have been neglected. The possible role of the whistler waves in the substorm process is discussed.

Suppressive effects of diltiazem and verapamil on delayed rectifier K(+)-channel currents in murine thymocytes.

Science.gov (United States)

Baba, Asuka; Tachi, Masahiro; Maruyama, Yoshio; Kazama, Itsuro

2015-10-01

Lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) in their plasma membranes, and these channels play crucial roles in the lymphocyte activation and proliferation. Since diltiazem and verapamil, which are highly lipophilic Ca(2+) channel blockers (CCBs), exert relatively stronger immunomodulatory effects than the other types of CCBs, they would affect the Kv1.3-channel currents in lymphocytes. Employing the standard patch-clamp whole-cell recording technique in murine thymocytes, we examined the effects of these drugs on the channel currents and the membrane capacitance. Both diltiazem and verapamil significantly suppressed the peak and the pulse-end currents of the channels, although the effects of verapamil were more marked than those of diltiazem. Both drugs significantly lowered the membrane capacitance, indicating the interactions between the drugs and the plasma membranes. This study demonstrated for the first time that CCBs, such as diltiazem and verapamil, exert inhibitory effects on Kv1.3-channels expressed in lymphocytes. The effects of these drugs may be associated with the mechanisms of immunomodulation by which they decrease the production of inflammatory cytokines. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Upper Atmospheric Studies using a 3D Embedded Reconfigurable Interferometer and NASA's THEMIS Space Probes

Science.gov (United States)

Dekoulis, George

2016-07-01

This paper describes the latest results obtained from the implementation of a new three-dimensional embedded reconfigurable interferometer that remotely senses the irregularities in the plasma present in the ionospheric-magnetospheric coupled system. The results are seriatim compared to the data obtained from NASA's THEMIS satellite cluster mission. The new instrument acts as a support in measuring the immense plasmasphere that surrounds Earth. The main scientific algorithms implemented into reconfigurable hardware are explained. The system performs regular self-calibration and automatically adjusts its settings to fully capture events associated to high heliospheric activity. The importance of studying the behavior of the energetic particles is explained. The energized particles are either restrained in the magnetospheric plasma or swift to the planet's surface through the coupled ionospheric-magnetospheric complex system. The various phenomena associated to the particles' movement are captured by the new system. Measurements that were obtained during intense solar activity are presented. The system captures activity related to particle precipitation of energy levels >9 KeV. Other instruments suitable for capturing activity related to energy levels <9 KeV are required for fully measuring the plasmaspheric conditions.

THEMIS Observations of the Magnetopause Electron Diffusion Region: Large Amplitude Waves and Heated Electrons

Science.gov (United States)

Tang, Xiangwei; Cattell, Cynthia; Dombeck, John; Dai, Lei; Wilson, Lynn B. III; Breneman, Aaron; Hupack, Adam

2013-01-01

We present the first observations of large amplitude waves in a well-defined electron diffusion region based on the criteria described by Scudder et al at the subsolar magnetopause using data from one Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite. These waves identified as whistler mode waves, electrostatic solitary waves, lower hybrid waves, and electrostatic electron cyclotron waves, are observed in the same 12 s waveform capture and in association with signatures of active magnetic reconnection. The large amplitude waves in the electron diffusion region are coincident with abrupt increases in electron parallel temperature suggesting strong wave heating. The whistler mode waves, which are at the electron scale and which enable us to probe electron dynamics in the diffusion region were analyzed in detail. The energetic electrons (approx. 30 keV) within the electron diffusion region have anisotropic distributions with T(sub e(right angle))/T(sub e(parallel)) > 1 that may provide the free energy for the whistler mode waves. The energetic anisotropic electrons may be produced during the reconnection process. The whistler mode waves propagate away from the center of the "X-line" along magnetic field lines, suggesting that the electron diffusion region is a possible source region of the whistler mode waves.

THEMIS satellite observations of hot flow anomalies at Earth's bow shock

Directory of Open Access Journals (Sweden)

C. Chu

2017-03-01

Full Text Available Hot flow anomalies (HFAs at Earth's bow shock were identified in Time History of Events and Macroscale Interactions During Substorms (THEMIS satellite data from 2007 to 2009. The events were classified as young or mature and also as regular or spontaneous hot flow anomalies (SHFAs. The dataset has 17 young SHFAs, 49 mature SHFAs, 15 young HFAs, and 55 mature HFAs. They span a wide range of magnetic local times (MLTs from approximately 7 to 16.5 MLT. The largest ratio of solar wind to HFA core density occurred near dusk and at larger distances from the bow shock. In this study, HFAs and SHFAs were observed up to 6.3 RE and 6.1 RE (Earth radii, respectively, upstream from the model bow shock. HFA–SHFA occurrence decreases with distance upstream from the bow shock. HFAs of the highest event core ion temperatures were not seen at the flanks. The ratio of HFA ion temperature increase to HFA electron temperature increase is highest around 12 MLT and slightly duskward. For SHFAs, (Tihfa∕Tisw/(Tehfa∕Tesw generally increased with distance from the bow shock. Both mature and young HFAs are more prevalent when there is an approximately radial interplanetary magnetic field. HFAs occur most preferentially for solar wind speeds from 550 to 600 km s−1. The correlation coefficient between the HFA increase in thermal energy density from solar wind values and the decrease in kinetic energy density from solar wind values is 0.62. SHFAs and HFAs do not show major differences in this study.

Bcl2-independent chromatin cleavage is a very early event during induction of apoptosis in mouse thymocytes after treatment with either dexamethasone or ionizing radiation.

Science.gov (United States)

Hahn, Peter J; Lai, Zhi-Wei; Nevaldine, Barbara; Schiff, Ninel; Fiore, Nancy C; Silverstone, Allen E

2003-11-01

We have quantified the emergence of early chromatin breaks during the signal transduction phase of apoptosis in mouse thymocytes after treatment with either ionizing radiation or dexamethasone. Dexamethasone at 1 microM can induce significant levels of DNA breaks (equivalent to the amount induced directly by 7.5 Gy ionizing radiation) within 0.5 h of treatment. The execution phase of apoptosis was not observed until 4-6 h after the same treatment. The presence of the Bcl2 transgene under the control of the p56lck promoter almost completely inhibited apoptosis up to 24 h after treatment, but it had virtually no effect on the early chromatin cleavage occurring in the first 6 h. Ionizing radiation induced chromatin cleavage both directly by damaging DNA and indirectly with kinetics similar to the induction of chromatin cleavage by dexamethasone. The presence of the Bcl2 transgene had no effect on the direct or indirect radiation-induced cleavage in the first 6 h, but after the first 6 h, the Bcl2 gene inhibited further radiation-induced chromatin cleavage. These results suggest that endonucleases are activated within minutes of treatment with either dexamethasone or ionizing radiation as part of the very early signal transduction phase of apoptosis, and prior to the irreversible commitment to cell death.

Overexpression of IL-7R alpha provides a competitive advantage during early T-cell development.

Science.gov (United States)

Laouar, Yasmina; Crispe, I Nicholas; Flavell, Richard A

2004-03-15

Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre-T-cell antigen receptor. Although alpha beta T-cell development is observed in IL-7- and IL-7R alpha-deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7R alpha that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7R alpha was revealed by surface staining, and increased IL-7R alpha mRNA was documented by using reverse transcriptase-polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL(+) (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]-fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.

Quasi-parallel whistler mode waves observed by THEMIS during near-earth dipolarizations

Directory of Open Access Journals (Sweden)

O. Le Contel

2009-06-01

Full Text Available We report on quasi-parallel whistler emissions detected by the near-earth satellites of the THEMIS mission before, during, and after local dipolarization. These emissions are associated with an electron temperature anisotropy α=T_⊥e/T_||e>1 consistent with the linear theory of whistler mode anisotropy instability. When the whistler mode emissions are observed the measured electron anisotropy varies inversely with β_||e (the ratio of the electron parallel pressure to the magnetic pressure as predicted by Gary and Wang (1996. Narrow band whistler emissions correspond to the small α existing before dipolarization whereas the broad band emissions correspond to large α observed during and after dipolarization. The energy in the whistler mode is leaving the current sheet and is propagating along the background magnetic field, towards the Earth. A simple time-independent description based on the Liouville's theorem indicates that the electron temperature anisotropy decreases with the distance along the magnetic field from the equator. Once this variation of α is taken into account, the linear theory predicts an equatorial origin for the whistler mode. The linear theory is also consistent with the observed bandwidth of wave emissions. Yet, the anisotropy required to be fully consistent with the observations is somewhat larger than the measured one. Although the discrepancy remains within the instrumental error bars, this could be due to time-dependent effects which have been neglected. The possible role of the whistler waves in the substorm process is discussed.

scid Thymocytes with TCRbeta gene rearrangements are targets for the oncogenic effect of SCL and LMO1 transgenes.

Science.gov (United States)

Chervinsky, D S; Lam, D H; Melman, M P; Gross, K W; Aplan, P D

2001-09-01

SCL and LMO1 were both discovered by virtue of their activation by chromosomaltranslocation in patients with T-cell acute lymphoblastic leukemia (T-ALL). Overexpression of SCL and LMO1 in the thymus of transgenic mice leads to T-ALL at a young age. scid (severe combined immunodeficient) mice are unable to efficiently recombine antigen receptor genes and consequently display a developmental block at the CD4-CD8- to CD4+CD8+ transition. To test the hypothesis that this developmental block would protect SCL/LMO1 transgenic mice from developing T-ALL, we crossed the SCL and LMO1 transgenes onto a scid background. The age of onset for T-ALL in the SCL/LMO1/scid mice was significantly delayed (P < 0.001) compared with SCL/LMO1/wild-type mice. Intriguingly, all of the SCL/LMO1/scid malignancies displayed clonal, in-frame TCRbeta gene rearrangements. Taken together, these findings suggest that the "leaky" scid thymocyte that undergoes a productive TCRbeta gene rearrangement is susceptible to the oncogenic action of SCL and LMO1 and additionally suggests that TCRbeta gene rearrangements may be required for the oncogenic action of SCL and LMO1.

Effects of ultraviolet radiation on the production of epidermal derived thymocyte-activating factor/interleukin-1

International Nuclear Information System (INIS)

Gahring, L.C.

1986-01-01

The effect of both a single exposure and multiple exposures to ultraviolet radiation (UVR) on the production and/or release of epidermal cell derived thymocyte activating factor/interleukin-1 (ETAF/IL-1) were investigated. A single exposure to UVR enhances the release of ETAF/IL-1 both in vitro and in vivo. This conclusion was based on the observation that: (1) in vitro UV-irradiation of the keratinocyte cell line elevated the release of ETAF/IL-1 on a per cell basis; (2) exposure of animals to UVR stimulated a number of in vivo biologic responses which are known to be mediated by ETAF/IL-1; and (3) ETAF/IL-1 could be detected in the serum of UVR exposed but not normal animals. Exposure of mice to UV-irradiation on a daily basis induced a desensitized state in which animals were found to be refractory to further stimulation with this inflammatory agent. A similar desensitization or tolerance was also shown to be induced by multiple intraperitoneal injections of bacterial lipopolysaccharide (LPS). Desensitization, induced by either LPS or UVR, was found to be regulated at the site of interaction between the cells capable of ETAF/IL-1 production and the exogenous inflammatory stimulus. The results indicate that the regulatory mechanisms for ETAF/IL-1 production which are employed by the keratinocyte are distinct from those regulating ETAF/Il-1 production by the macrophage

Repopulation of the atrophied thymus in diabetic rats by insulin-like growth factor I

International Nuclear Information System (INIS)

Binz, K.; Joller, P.; Froesch, P.; Binz, H.; Zapf, J.; Froesch, E.R.

1990-01-01

Atrophy of the thymus is one of the consequences of severe insulin deficiency. The authors describe here that the weight and the architecture of the thymus of diabetic rats is restored towards normal not only by insulin but also by insulin-like growth factor I (IGF-I) treatment. In contrast to insulin, this effect of IGF-I occurs despite persisting hyperglycemia and adrenal hyperplasia. They also investigated the in vivo effect of IGF-I on replication and differentiation of thymocytes from streptozotocin-induced diabetic rats. Thymocytes from diabetic rats incorporated less [ 3 H]thymidine than did thymocytes from healthy rats. Insulin, as well as IGF-I treatment of diabetic rats increased [ 3 H]thymidine incorporation by thymocytes. Flow cytometry of thymocytes labeled with monoclonal antibodies revealed a decreased expression of the Thy-1 antigen in diabetic rats compared with control rats. In addition, a major deficiency of thymocytes expressing simultaneously the W3/25 and the Ox8 antigens was observed. These changes were restored towards normal by insulin as well as by IGF-I treatment. The antibody response to a T cell-dependent antigen (bovine serum albumin) was comparable in normal and diabetic rats. They conclude that IGF-I has important effects on the thymocyte number and the presence of CD4 + /CD8 + immature cells in the thymus of diabetic rats despite persisting hyperglycemia. However, helper T-cell function for antibody production appears to be preserved even in the severely diabetic state

Traveling magnetopause distortion related to a large-scale magnetosheath plasma jet: THEMIS and ground-based observations

Science.gov (United States)

Dmitriev, A. V.; Suvorova, A. V.

2012-08-01

Here, we present a case study of THEMIS and ground-based observations of the perturbed dayside magnetopause and the geomagnetic field in relation to the interaction of an interplanetary directional discontinuity (DD) with the magnetosphere on 16 June 2007. The interaction resulted in a large-scale local magnetopause distortion of an "expansion - compression - expansion" (ECE) sequence that lasted for ˜15 min. The compression was caused by a very dense, cold, and fast high-βmagnetosheath plasma flow, a so-called plasma jet, whose kinetic energy was approximately three times higher than the energy of the incident solar wind. The plasma jet resulted in the effective penetration of magnetosheath plasma inside the magnetosphere. A strong distortion of the Chapman-Ferraro current in the ECE sequence generated a tripolar magnetic pulse "decrease - peak- decrease" (DPD) that was observed at low and middle latitudes by some ground-based magnetometers of the INTERMAGNET network. The characteristics of the ECE sequence and the spatial-temporal dynamics of the DPD pulse were found to be very different from any reported patterns of DD interactions with the magnetosphere. The observed features only partially resembled structures such as FTE, hot flow anomalies, and transient density events. Thus, it is difficult to explain them in the context of existing models.

Dynamics of Lymphocyte Populations during Trypanosoma cruzi Infection: From Thymocyte Depletion to Differential Cell Expansion/Contraction in Peripheral Lymphoid Organs

Directory of Open Access Journals (Sweden)

Alexandre Morrot

2012-01-01

Full Text Available The comprehension of the immune responses in infectious diseases is crucial for developing novel therapeutic strategies. Here, we review current findings on the dynamics of lymphocyte subpopulations following experimental acute infection by Trypanosoma cruzi, the causative agent of Chagas disease. In the thymus, although the negative selection process of the T-cell repertoire remains operational, there is a massive thymocyte depletion and abnormal release of immature CD4+CD8+ cells to peripheral lymphoid organs, where they acquire an activated phenotype similar to activated effector or memory T cells. These cells apparently bypassed the negative selection process, and some of them are potentially autoimmune. In infected animals, an atrophy of mesenteric lymph nodes is also observed, in contrast with the lymphocyte expansion in spleen and subcutaneous lymph nodes, illustrating a complex and organ specific dynamics of lymphocyte subpopulations. Accordingly, T- and B-cell activation is seen in subcutaneous lymph nodes and spleen, but not in mesenteric lymph nodes. Lastly, although the function of peripheral CD4+CD8+ T-cell population remains to be defined in vivo, their presence may contribute to the immunopathological events found in both murine and human Chagas disease.

Open questions on prominences from coordinated observations by IRIS, Hinode, SDO/AIA, THEMIS, and the Meudon/MSDP

Science.gov (United States)

Schmieder, B.; Tian, H.; Kucera, T.; López Ariste, A.; Mein, N.; Mein, P.; Dalmasse, K.; Golub, L.

2014-09-01

Context. A large prominence was observed by multiple instruments on the ground and in space during an international campaign on September 24, 2013, for three hours (12:12 UT -15:12 UT). Instruments used in the campaign included the newly launched (June 2013) Interface Region Imaging Spectrograph (IRIS), THEMIS (Tenerife), the Hinode Solar Optical Telescope (SOT), the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA), and the Multichannel Subtractive Double Pass spectrograph (MSDP) in the Meudon Solar Tower. The movies obtained in 304 Å with the EUV imager SDO/AIA, and in Ca II line by SOT show the dynamic nature of the prominence. Aims: The aim of this work is to study the dynamics of the prominence fine structures in multiple wavelengths to understand their formation. Methods: The spectrographs IRIS and MSDP provided line profiles with a high cadence in Mg II h (2803.5 Å) and k (2796.4 Å) lines along four slit positions (IRIS), and in Hα in a 2D field of view (MSDP). The spectropolarimetry of THEMIS (Tenerife) allowed us to derive the magnetic field of the prominence using the He D3 line depolarization (Hanle effect combined with the Zeeman effect). Results: The magnetic field is found to be globally horizontal with a relatively weak field strength (8-15 Gauss). On the other hand, the Ca II movie reveals turbulent-like motion that is not organized in specific parts of the prominence. We tested the addition of a turbulent magnetic component. This model is compatible with the polarimetric observations at those places where the plasma turbulence peaks. On the other hand, the Mg II line profiles show multiple peaks well separated in wavelength. This is interpreted by the existence of small threads along the line of sight with a large dispersion of discrete values of Doppler shifts, from 5 km s-1 (a quasi-steady component) to 60-80 km s-1. Each peak corresponds to a Gaussian profile, and not to a reversed profile as was expected by the present non

Induction by anti-thymocyte globulins in kidney transplantation: a review of the literature and current usage.

Science.gov (United States)

Malvezzi, Paolo; Jouve, Thomas; Rostaing, Lionel

2015-10-01

Preventing acute rejection (AR) after kidney transplantation is of utmost importance because an AR can have a negative impact on long-term allograft survival. Directory of Open Access Journals (DOAJ), Google Scholar, PubMed, EBSCO, and Web of Science have been searched. At the moment this can be done by using rabbit anti-thymocyte globulins (rATGs) as an induction therapy. However, because rATGs are associated with some deleterious side-effects, such as the opportunistic infections cytomegalovirus (CMV) and de novo post-transplant cancer, it is very important they are used optimally, i.e., at minimal doses that avoid many side-effects but still retain optimal treatment efficacy. Recent data show that the risk of CMV infection can be minimized using tacrolimus plus everolimus, and not tacrolimus plus mycophenolic acid, as the maintenance immunosuppression. The use of rATG is particularly valuable in; (a) sensitized patients; (b) in recipients from an expanded-criteria donor, thus enabling the introduction of calcineurin inhibitors at reduced doses; and (c) for patients where steroid avoidance is contemplated. However, we also need to consider that rATG may increase the risk of de novo cancer, even though recent data indicate this is unlikely and that any risk can be reduced by using mammalian target of rapamycin (mTOR) inhibitors instead of mycophenolic acid combined with low-dose calcineurin inhibitors. Even though rATGs do not improve long-term kidney-allograft survival, they may help reduce calcineurin-inhibitor dosage during the early post-transplant period and minimize the risk of AR.

Elimination of self-reactive T cells in the thymus: a timeline for negative selection.

Directory of Open Access Journals (Sweden)

Ivan Lilyanov Dzhagalov

Full Text Available The elimination of autoreactive T cells occurs via thymocyte apoptosis and removal by thymic phagocytes, but the sequence of events in vivo, and the relationship between thymocyte death and phagocytic clearance, are unknown. Here we address these questions by following a synchronized cohort of thymocytes undergoing negative selection within a three-dimensional thymic tissue environment, from the initial encounter with a negative selecting ligand to thymocyte death and clearance. Encounter with cognate peptide-MHC complexes results in rapid calcium flux and migratory arrest in auto-reactive thymocytes over a broad range of peptide concentrations, followed by a lag period in which gene expression changes occurred, but there was little sign of thymocyte death. Caspase 3 activation and thymocyte loss were first detectable at 2 and 3 hours, respectively, and entry of individual thymocytes into the death program occurred asynchronously over the next 10 hours. Two-photon time-lapse imaging revealed that thymocyte death and phagocytosis occurred simultaneously, often with thymocytes engulfed prior to changes in chromatin and membrane permeability. Our data provide a timeline for negative selection and reveal close coupling between cell death and clearance in the thymus.

Kinetic-Scale Electric and Magnetic Field Fluctuations in the Solar Wind at 1 AU: THEMIS/ARTEMIS Observations

Science.gov (United States)

Salem, C. S.; Hanson, E.; Bonnell, J. W.; Chaston, C. C.; Bale, S. D.; Mozer, F.

2017-12-01

We present here an analysis of kinetic-scale electromagnetic fluctuations in the solar wind using data from THEMIS and ARTEMIS spacecraft. We use high-time resolution electric and magnetic field measurements, as well as density fluctuations, up to 128 samples per second, as well as particle burst plasma data during carefully selected solar wind intervals. We focus our analysis on a few such intervals spanning different values of plasma beta and angles between the local magnetic field and the radial Sun-Earth direction. We discuss the careful analysis process of characterizing and removing the different instrumental effects and noise sources affecting the electric and magnetic field data at those scales, above 0.1 Hz or so, above the breakpoint marking the start of the so-called dissipation range of solar wind turbulence. We compute parameters such as the electric to magnetic field ratio, the magnetic compressibility, magnetic helicity, and other relevant quantities in order to diagnose the nature of the fluctuations at those scales between the ion and electron cyclotron frequencies, extracting information on the dominant modes composing the fluctuations. We also discuss the presence and role of coherent structures in the measured fluctuations. The nature of the fluctuations in the dissipation or dispersive scales of solar wind turbulence is still debated. This observational study is also highly relevant to the current Turbulent Dissipation Challenge.

Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

International Nuclear Information System (INIS)

Dong, Guang-Hui; Wang, Jing; Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da; Zheng, Li; Jin, Yi-He

2012-01-01

Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

Induction of p53-mediated apoptosis in splenocytes and thymocytes of C57BL/6 mice exposed to perfluorooctane sulfonate (PFOS)

Energy Technology Data Exchange (ETDEWEB)

Dong, Guang-Hui, E-mail: ghdong@mail.cmu.edu.cn [School of Public Health, China Medical University, Shenyang 110001 (China); Wang, Jing [Department of Biostatistics, School of Public Health, Saint Louis University, Saint Louis, MO 63104 (United States); Zhang, Ying-Hua; Liu, Miao-Miao; Wang, Da [School of Public Health, China Medical University, Shenyang 110001 (China); Zheng, Li [Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Jin, Yi-He [School of Public Health, China Medical University, Shenyang 110001 (China); School of Environmental Science and Technology, Dalian University of Technology, Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian 116024 (China)

2012-10-15

Perfluorooctane sulfonate (PFOS) is a persistent environmental contaminant found in human and wildlife tissues. It has been reported that PFOS can cause atrophy of the immune organs and apoptosis of immunocytes in rodents. However, the mechanism behind such cause is still unclear. To understand the model of cell death and its mechanism on lymphoid cells in vivo, we conducted a dose/response experiment in which 4 groups of male adult C57BL/6 mice (12 mice per group) were dosed daily by oral gavage with PFOS at 0, 0.0167, 0.0833, or 0.8333 mg/kg/day, yielding targeted Total Administered Dose (TAD) of 0, 1, 5, or 50 mg PFOS/kg, respectively, over 60 days. The results showed that spleen and thymus weight were significantly reduced in the highest PFOS-dose-group (TAD 50 mg PFOS/kg) compared to the control group, whereas liver weight was significantly increased. We analyzed the cell death via apoptosis with an annexin-V/propidium iodide assay by flow cytometry, and observed that both the percentage of apoptosis and the expression of the pro-apoptotic proteins p53 in splenocytes and thymocytes increased in a dose-related manner after PFOS treatment. We also observed that PFOS induced p53-dependent apoptosis through the cooperation between the Bcl-xl down regulation without changing the Bcl-2 and Bax expression. The down regulation of Bcl-xl was strongly indicating mitochondrial involvement in apoptosis. It is confirmed by the release of cytochrome c and activation of caspase-3. All of these findings establish an important role of p53 and mitochondrial function in PFOS induced toxic environment in the host. -- Highlights: ► PFOS immunotoxicity is caused by induction of apoptosis via the p53 activation. ► PFOS exposure can induce down regulation of Bcl-xl. ► Mitochondria are involved in PFOS-induced apoptosis. ► PFOS exposure can cause the release of cytochrome c and activation of caspase-3.

Plasma jets and FTE Dayside Generation for Northward IMF on 8 June 2007: THEMIS Observations

Science.gov (United States)

Eriksson, S.; Cully, C. M.; Ergun, R. E.; Gosling, J. T.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.; Glassmeier, K.; Roux, A.; Auster, H.; Le Contel, O.

2007-12-01

Five-spacecraft THEMIS (TH) observations are presented for a 15.5 MLT equatorial magnetopause crossing on 8 June 2007 when the upstream IMF was predominantly northward with a negative IMF By component at Wind. During the 0650-0855 UT period on this day TH-B was the most tailward probe while TH-A was the most sunward probe. TH-E was closest to TH-A with a maximum separation of only 0.71 RE. The maximum TH-A to TH-B GSM separation was 1.85 RE. TH-B showed a clean magnetopause crossing into the magnetosphere as the magnetopause expanded over the probes while TH-A spent this 2-hour period within a boundary layer inside the magnetopause with frequent transitions between a magnetosheath-like and a magnetosphere-like plasma as previously seen by Cluster at high-latitudes for southward IMF [Wild et al., 2003]. TH-E observed similar activity for a shorter period of time. Many of the sheath-like transitions showed evidence of plasma jets at TH-A with enhanced speed in the tailward and/or duskward direction suggesting a subsolar component merging region. Some jets were related to frequent bipolar FTE signatures in the normal BN component with enhanced total pressure observed at their centers. The more common ±BN sequence suggests that TH-A observed tailward propagating FTEs on the sheath side of the magnetopause. We compare TH-E ExB velocities with the enhanced jet velocities observed by TH-A and discuss whether the jets observed within this boundary layer were caused by subsolar magnetopause reconnection. We also compare these low-latitude northward IMF observations with prior Cluster FTE observations at high-latitude for southward IMF.

Nuclear Wiskott–Aldrich syndrome protein co-regulates T cell factor 1-mediated transcription in T cells

Directory of Open Access Journals (Sweden)

Nikolai V. Kuznetsov

2017-10-01

Full Text Available Abstract Background The Wiskott–Aldrich syndrome protein (WASp family of actin-nucleating factors are present in the cytoplasm and in the nucleus. The role of nuclear WASp for T cell development remains incompletely defined. Methods We performed WASp chromatin immunoprecipitation and deep sequencing (ChIP-seq in thymocytes and spleen CD4+ T cells. Results WASp was enriched at genic and intergenic regions and associated with the transcription start sites of protein-coding genes. Thymocytes and spleen CD4+ T cells showed 15 common WASp-interacting genes, including the gene encoding T cell factor (TCF12. WASp KO thymocytes had reduced nuclear TCF12 whereas thymocytes expressing constitutively active WASpL272P and WASpI296T had increased nuclear TCF12, suggesting that regulated WASp activity controlled nuclear TCF12. We identify a putative DNA element enriched in WASp ChIP-seq samples identical to a TCF1-binding site and we show that WASp directly interacted with TCF1 in the nucleus. Conclusions These data place nuclear WASp in proximity with TCF1 and TCF12, essential factors for T cell development.

A THEMIS Case Study of Pi2 Pulsations in the Magnetotail and on the Ground Before a Substorm Onset

Science.gov (United States)

Miyashita, Y.; Angelopoulos, V.; Hiraki, Y.; Ieda, A.; Machida, S.

2016-12-01

Using THEMIS spacecraft and ground data, we studied low-frequency Pi2 pulsations in the magnetotail and on the ground just before a substorm onset. A case study shows that a new compressional Pi2 pulsation was observed in the plasma sheet just earthward of the near-Earth reconnection site 4 min before initial auroral brightening or 2 min before auroral fading. The ion and magnetic pressure perturbations appeared to be partly in phase at the beginning, indicating that the wave had fast mode. A similar wave was observed also tailward of the near-Earth reconnection site, although it occurred 4 min later. These waves may have been generated at the near-Earth reconnection site. On the ground, Pi2 pulsations were observed widely in the polar cap and at the auroral oval before initial auroral brightening and auroral fading, although the amplitudes were small, compared to those associated with auroral poleward expansion. There was a tendency that the waves were observed first in the polar cap near the initial auroral brightening site and then in the surrounding regions. Ionospheric convection began to be enhanced gradually 1 or 2 min after the Pi2 onsets. We discuss the causal relationship between the Pi2 pulsations in the magnetotail and on the ground as well as their role in substorm triggering.

Anti-thymocyte globulin could improve the outcome of allogeneic hematopoietic stem cell transplantation in patients with highly aggressive T-cell tumors

International Nuclear Information System (INIS)

Yang, J; Cai, Y; Jiang, J L; Wan, L P; Yan, S K; Wang, C

2015-01-01

The early experiment result in our hospital showed that anti-thymocyte globulin (ATG) inhibited the proliferation of lymphoid tumor cells in the T-cell tumors. We used the ATG as the part of the conditioning regimen and to evaluate the long-term anti-leukemia effect, the safety and complication in the patients with highly aggressive T-cell lymphomas. Twenty-three patients were enrolled into this study. At the time of transplant, six patients reached first or subsequent complete response, three patients had a partial remission and 14 patients had relapsed or primary refractory disease. The conditioning regimen consisted of ATG, total body irradiation, toposide and cyclophosphamide. The complete remission rate after transplant was 95.7%. At a median follow-up time of 25 months, 16 (69.6%) patients are alive and free from diseases, including nine patients in refractory and progressive disease. Seven patients died after transplant, five from relapse and two from treatment-related complications. The incidence of grades II–IV acute graft-vs-host disease (GvHD) was 39.1%. The maximum cumulative incidence of chronic GvHD was 30%. The most frequent and severe conditioning-related toxicities observed in 8 out of 23 patients were grades III/IV infections during cytopenia. Thus, ATG-based conditioning is a feasible and effective alternative for patients with highly aggressive T-cell tumors

Lymphocyte depletion in thymic nurse cells: a tool to identify in situ lympho-epithelial complexes having thymic nurse cell characteristics

NARCIS (Netherlands)

Leene, W.; de Waal Malefijt, R.; Roholl, P. J.; Hoeben, K. A.

1988-01-01

In situ pre-existing complexes of epithelial cells and thymocytes having thymic nurse cell characteristics were visualized in the murine thymus cortex using dexamethasone as a potent killer of cortisone-sensitive thymocytes. The degradation and subsequent depletion of cortisone-sensitive thymocytes

Observations of plasma vortices in the vicinity of flow-braking: a case study

Directory of Open Access Journals (Sweden)

K. Keika

2009-08-01

Full Text Available We examine fast plasma flows and magnetic field fluctuations observed by THEMIS at 03:00–03:30 UT on 12 December 2007. All THEMIS probes are situated in the near-Earth plasma sheet (XSM>−10 RE with 1–2 RE spacecraft separations in azimuthal and radial directions. We focus on the observations of plasma convective flows made simultaneously by more than one THEMIS probe. At about 03:10 UT and 03:14 UT, the THEMIS P2 probe observed earthward flows of >100 km/s. The THEMIS P1 probe, located duskward and earthward of P2, observed tailward flows under a positive Bz. The inner most probe THEMIS P4, located at almost the same MLT as THEMIS P1 and P2, did not see any clear flow. We examine the convective flow patterns for the THEMIS observations. We conclude that plasma vortices are formed near the region where the earthward flows slow down and turn in azimuthal directions.

Experiment list: SRX099379 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 66262,95.2,8.3,424 GSM803107: input DNA Ikaros knockout chromatin source_name=mouse Ik knockout DP thymocyte...s || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || chip

Effect of radiation and alkylating agents on chromatin degradation in normal and malignant lymphoid cells

International Nuclear Information System (INIS)

Ryabchenko, N.I.; Yurashkova, V.; Ivannik, B.P.; Konov, A.V.; Drashil, V.

1991-01-01

Regularities of chromatin degradation in thymocytes and LS/BL tumor cells have been investigated. It has been shown that the rate of DNA degradation by Ca/Mg-dependent endonuclease in LS/BL tumor cells is 25 times lower than that in thymocytes, and radiation does not induce chormatin degradation. The alkylating agent TS 160 causes chromatin degradation in both LS/Bl cells and thymocytes. In contrast to radiation TS 160 inhibits the endogenous chromatin degradation by Ca/Mg-dependent endonuclease in thymocytes

Cluster and THEMIS observations of the magnetosphere dayside boundaries in preparation for the SMILE mission

Science.gov (United States)

Escoubet, C. P.; Dimmock, A. P.; Walsh, B.; Sibeck, D. G.; Berchem, J.; Nykyri, K.; Turc, L.; Read, A.; Branduardi-Raymont, G.; Wang, C.; Sembay, S.; Kuntz, K. D.; Dai, L.; Li, L.; Donovan, E.; Spanswick, E.; Laakso, H. E.; Zheng, J.; Rebuffat, D.

2016-12-01

Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a novel self-standing mission, in collaboration between ESA and Chinese Academy of Science. Its objective is to observe the solar wind-magnetosphere coupling via simultaneous in situ solar wind/magnetosheath plasma and magnetic field measurements, soft X-Ray images of the magnetosheath and polar cusps, and UV images of global auroral distributions. The observations of the cusps and magnetosheath with the X-ray imager are possible through the relatively recent discovery of solar wind charge exchange (SWCX) X-ray emission, first observed at comets, and subsequently found to occur in the vicinity of the Earth's magnetosphere. In preparation for the mission, we need to determine the cusp's morphology, motion and in situ properties (density, velocity, temperature) that are expected to be observed by the spacecraft. To do so, we have selected a series of cusp crossings by the Cluster spacecraft that can be used to simulate X-ray emissions across the width of the cusp for different IMF orientations. In view of the well-known cusp ion dispersions, we expect that X ray emissions peak near the equatorial boundary of the cusp for southward IMF Bz, but near the poleward boundary of the cusp for northward IMF Bz. We also employ Cluster cusp observations during storms to predict X-ray emissions to be expected for periods of high solar wind fluxes. In addition, we use THEMIS observations from January 2008 to July 2015 for moderate (nsw*vsw 4.9x10^8 /cm^2s) solar wind fluxes to investigate X-rays emitted by the magnetosheath and to determine their variation as a function of distance from the subsolar point along the Sun-Earth line and along the flanks of the magnetosphere. We will show that high solar wind fluxes greatly enhance soft X-ray emissions, not only because solar wind fluxes increases but also because the emission region moves deeper within the Earth's exosphere.

'Motheaten': a single gene model for stem cell dysfunction and early onset autoimmunity

International Nuclear Information System (INIS)

Shultz, L.D.; Zurier, R.B.

1978-01-01

Mice homozygous for the recessive mutation called 'motheaten' (me) develop autoantibodies against thymocytes and double stranded DNA by three weeks of age. Sera from littermate control mice were consistently negative for these autoantibodies. The thymocytotoxic autoantibody was an IgM immunoglobulin as determined by its sensitivity to 2-mercaptoethanol. This autoantibody selectively killed immature thymocytes and reacted equally well against thymocytes of all strains tested regardless of H-2 haplotype, Thy-1 or TLA specificity. Lymphoid cells from spleen, lymph node, Peyer's patch and peripheral blood were not sensitive to killing by motheaten serum. Motheaten mice appear to have increased numbers of stem cells as determined by the spleen colony assay. However, bone marrow from this mutant does not save lethally irradiated syngeneic recipients. Sublethally-irradiated subgeneic recipients of motheaten bone marrow develop hyperimmunoglobulinemia and antinuclear antibodies. Transfer of bone marrow from motheaten mice into congenitally anemic W/Wsup(v) recipients resulted in a cure of the anemia and the development of hyperimmunoglobulinemia and autoimmunity. (Auth.)

Ornithine decarboxylase activity in rat organs and tissues under artificial hypobiosis.

Science.gov (United States)

Aksyonova, G E; Logvinovich, O S; Fialkovskaya, L A; Afanasyev, V N; Ignat'ev, D A; Kolomiytseva, I K

2010-09-01

The influence of hypothermia-hypoxia-hypercapnia on ornithine decarboxylase (ODC, EC 4.1.1.17) activities in rat organs and tissues and also on the thymocyte distribution throughout the cell cycle stages was studied. The state of artificial hypobiosis in rats on decrease in the body temperature to 14.4-18.0°C during 3.0-3.5 h was accompanied by drops in the ODC activities in the neocortex and liver by 50-60% and in rapidly proliferating tissues (thymus, spleen, and small intestine mucosa) by 80% of the control value. In kidneys the ODC activity raised to 200% of the control level. Twenty-four hours after termination of the cooling and replacing the rats under the standard conditions, the ODC activities in the neocortex, liver, kidneys, spleen, and intestinal mucosa returned to the control values, but remained decreased in the thymus. Forty-eight hours later the ODC activities in the thymus and spleen exceeded the normal level. The distribution of thymocytes throughout the cell cycle stages did not change in rats in the state of hypothermia (hypobiosis); 24 and 48 h after termination of the cooling the fraction of thymocytes in the S stage was decreased and the fraction of the cells in the G(0)+G(1) stage was increased. The normal distribution of thymocytes throughout the cell cycle stages recovered in 72 h. Thus, in the thymus the diminution of the ODC activity preceded the suppression of the cell proliferation rate. The tissue-specific changes in the ODC activity are suggested to reflect adaptive changes in the functional and proliferative activities of organs and tissues during the development of hypobiosis under conditions of hypothermia-hypoxia-hypercapnia.

Comparison of daclizumab, an interleukin 2 receptor antibody, to anti-thymocyte globulin-Fresenius induction therapy in kidney transplantation.

Science.gov (United States)

Abou-Jaoude, Maroun M; Ghantous, Imad; Almawi, Wassim Y

2003-07-01

The efficacy and safety of daclizumab and anti-thymocyte globulin-Fresenius (ATG-F) as induction therapy in kidney transplantation (KT) were investigated in 45 KT performed in our center between March and May 2002. Group II (n=10) received daclizumab as induction therapy, and Group I (n=35) were induced with a single intraoperative bolus therapy of ATG-F. All patients were at low-risk, and the recipient and donor demographics, as well the immunosuppression regimen employed were comparable in both groups. Drug safety, assessed by the occurrence of side effects, was almost comparable in the two groups, except for more thrombocytopenia in Group II (P<0.0004). Acute rejection (AR) occurred in 10% in Group I and 11.4% in Group II (P=NS). There were more infections in Group II (42.8%) than in Group I (10%) (P<0.009). Bacterial and viral infections were more common in Group II (69 and 23%) than in Group I (10 and 0%) (P<0.05). The hospital stay was similar in both groups. Mean serum creatinine levels upon discharge, at 1, 3 and 6 months were: 1.23+/-0.11, 1.21+/-0.06, 1.25+/-0.11 and 1.35+/-0.08 in Group I and 2.18+/-0.43, 1.49+/-0.16, 1.49+/-0.16 and 1.35+/-0.08 in Group II, respectively. While better serum creatinine levels were observed in Group I upon discharge (P<0.048), this was due to the presence of more sensitized patients in Group II. The 6 months actuarial patient and graft survival were identical in both groups (100 and 100%, respectively). Although both daclizumab and ATG-F were effective and safe as induction therapy in KT, less bacterial and viral infections and lower early serum creatinine levels were noted in daclizumab-treated patients.

Intrathymic laminin-mediated interactions: role in T cell migration and development

Directory of Open Access Journals (Sweden)

Wilson eSavino

2015-11-01

Full Text Available Intrathymic T cell differentiation is a key process for the development and maintenance of cell-mediated immunity, and occurs concomitantly to highly regulated migratory events. We have proposed a multivectorial model for describing intrathymic thymocyte migration. One of the individual vectors comprises interactions mediated by laminins, a heterotrimeric protein family of the extracellular matrix. Several laminins are expressed in the thymus, being produced by microenvironmental cells, particularly thymic epithelial cells. Also, thymocytes and epithelial cells express integrin-type laminin receptors. Functionally, it has been reported that the dy/dy mutant mouse (lacking the laminin isoform 211 exhibits defective thymocyte differentiation. Several data show haptotactic effects of laminins upon thymocytes, as well as their adhesion on thymic epithelial cells; both effects being prevented by anti-laminin or anti-laminin receptor antibodies. Interestingly, laminin synergizes with chemokines to enhance thymocyte migration, whereas classe-3 semaphorins and B ephrins, which exhibit chemorepulsive effects in the thymus, downregulate laminin-mediated migratory responses of thymocytes. More recently, we showed that knocking down the ITGA6 gene (which encodes the α6 integrin chain of laminin receptors in human thymic epithelial cells, modulates a large number of cell-migration related genes, and results in changes of adhesion pattern of thymocytes onto the thymic epithelium. Overall, laminin-mediated interactions can be placed at the cross-road of the multivectorial process of thymocyte migration, with a direct influence per se, as well as by modulating other molecular interactions associated with the intrathymic trafficking events.

Interleukin 4 increases CCR9 expression and homing of lymphocytes to gut-associated lymphoid tissue in chickens.

Science.gov (United States)

Annamalai, Thavamathi; Selvaraj, Ramesh K

2012-01-15

The effects of in vitro and in vivo IL-4 supplementation on thymocyte and splenocyte CCR9 mRNA amount and migration were studied. Thymocytes, splenocytes, splenocytes+thymocytes (2:1), and splenocytes+bursocyte cells (2:1) were supplemented with either 0 or 5 ng/ml IL-4 for 5d. CCR9 mRNA was undetectable in all experimental groups supplemented with 0 ng/ml IL-4. IL-4 treatment (5 ng/ml) upregulated (P=0.01) CCR9 mRNA only in the splenocyte+thymocyte cell culture. IL-4-mediated CCR9 mRNA induction in the splenocyte+thymocyte cell culture was dependent on the in vitro dose of IL-4 supplementation. IL-4-treated splenocyte+thymocyte cells when injected in vivo preferentially migrated to cecal tonsils. In vivo supplementation of IL-4 was achieved through in ovo injection of recombinant chicken IL-4 plasmid. Cecal tonsils in chicks hatched from IL-4-plasmid-injected eggs weighed more, had a higher amount of CCR9 mRNA, and had a higher percentage of CD8(+) cells than cecal tonsils from chicks hatched from PBS-injected eggs. It could be concluded that IL-4 induces CCR9 mRNA in thymocytes and splenocytes and directs the migration of cells to gut-associated lymphoid tissue. Copyright © 2011 Elsevier B.V. All rights reserved.

Survey of Pc3-5 ULF velocity oscillations in SuperDARN THEMIS-mode data: Occurrence statistics and driving mechanisms

Science.gov (United States)

Shi, X.; Ruohoniemi, J. M.; Baker, J. B.; Lin, D.; Bland, E. C.; Hartinger, M.; Scales, W.

2017-12-01

Ultra-low frequency (ULF: 1 mHz-10 Hz) waves are believed to play an important role in the energization and transport of plasma within the magnetosphere-ionosphere system, as well as the transfer of energy from the solar wind. Most previous statistical studies of ionospheric ULF waves using Super Dual Auroral Radar Network (SuperDARN) data have been constrained to the Pc5 band ( 1-7 mHz) and/or one or two radars covering a limited range of latitudes. This is partially due to lack of a database cataloging high time resolution data and an efficient way to identify wave events. In this study, we conducted a comprehensive survey of ULF wave signatures in the Pc3-5 band using 6 s resolution data from all SuperDARN radars in the northern hemisphere operating in THEMIS-mode from 2010 to 2016. Numerical experiments were conducted to derive dynamic thresholds for automated detection of ULF waves at different frequencies using the Lomb-Scargle periodogram technique. The spatial occurrence distribution, frequency characteristics, seasonal effects, solar wind condition and geomagnetic activity level dependence have been studied. We found Pc5 events dominate at high latitudes with a most probable frequency of 2 mHz while Pc3-4 are relatively more common at mid-latitudes on the nightside with a most probable frequency of 11 mHz. At high latitudes the occurrence rate of poloidal Pc3-5 peaks in the dusk sector and in winter while at mid-latitudes the poloidal Pc3-4 occurrence rate peaks at pre-midnight. This pre-midnight occurrence peak becomes more prominent with increasing AE index value, in equinox and during southward IMF, which suggests many of these events are most likely Pi2 pulsations associated with magnetotail dynamics during active geomagnetic intervals.

Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor

Energy Technology Data Exchange (ETDEWEB)

Kim, So Yong; Lim, Ju Hyun [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Choi, Sung Won [Department of Molecular Biology, School of Arts and Sciences (S.W.C), Cornell University, Ithaca, NY 18450 (United States); Kim, Miyoung; Kim, Seong-Tae [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Kim, Min-Seon; Cho, You Sook [Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-600 (Korea, Republic of); Chun, Eunyoung, E-mail: chun.eunyoung@gmail.com [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); Lee, Ki-Young, E-mail: thylee@med.skku.ac.kr [Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of)

2010-04-09

Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.

Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor

International Nuclear Information System (INIS)

Kim, So Yong; Lim, Ju Hyun; Choi, Sung Won; Kim, Miyoung; Kim, Seong-Tae; Kim, Min-Seon; Cho, You Sook; Chun, Eunyoung; Lee, Ki-Young

2010-01-01

Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.

A THEMIS Survey of Flux Ropes and Traveling Compression Regions: Location of the Near-Earth Reconnection Site During Solar Minimum

Science.gov (United States)

Imber, S. M.; Slavin, J. A.; Auster, H. U.; Angelopoulos, V.

2011-01-01

A statistical study of flux ropes and traveling compression regions (TCRs) during the Time History of Events and Macroscale Interactions during Substorms (THEMIS) second tail season has been performed. A combined total of 135 flux ropes and TCRs in the range GSM X approx -14 to -31 R(sub E) were identified, many of these occurring in series of two or more events separated by a few tens of seconds. Those occurring within 10 min of each other were combined into aggregated reconnection events. For the purposes of this survey, these are most likely the products of reconnect ion occurring simultaneously at multiple, closely spaced x-lines as opposed to statistically independent episodes of reconnection. The 135 flux ropes and TCRs were grouped into 87 reconnection events; of these, 28 were moving tailward and 59 were moving Earthward. The average location of the near-Earth x-line determined from statistical analysis of these reconnection events is (X(sub GSM), Y*(sub GSM)) = (-30R(sub E), 5R(sub E)), where Y* includes a correction for the solar aberration angle. A strong east-west asymmetry is present in the tailward events, with >80% being observed at GSM Y* > O. Our results indicate that the Earthward flows are similarly asymmetric in the midtail region, becoming more symmetric inside - 18 R(sub E). Superposed epoch analyses indicate that the occurrence of reconnection closer to the Earth, i.e., X > -20 R(sub E), is associated with elevated solar wind velocity and enhanced negative interplanetary magnetic field B(sub z). Reconnection events taking place closer to the Earth are also far more effective in producing geomagnetic activity, judged by the AL index, than reconnection initiated beyond X approx -25 R(sub E).

Experiment list: SRX099378 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 2.5,9.2,1453 GSM803106: Aio Ikaros knockout chromatin source_name=mouse Ik knockout DP thymocytes || genetic... background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || chip antibody=hom

Effects of gamma-rays on morphology of the thymus of the adult fish of Oryzias latipes

International Nuclear Information System (INIS)

Ghoneum, M.M.H.; Ijiri, Ken-ichi; Egami, Nobuo

1982-01-01

The effects of gamma-rays on the thymus in the adult fish of Oryzias latipes were studied. Fish were subjected to a single whole-body irradiation of the dose ranging from 0 to 8 kR. Through the histological sections, the quantitative treatment was performed on the changes in thymus volume and mitotic activity of thymocytes after irradiation. The thymus in the irradiated fish exhibited a sudden drop in its volume on day 1-3 post-irradiation, subsequently followed by its regeneration. The change in mitotic index of thymocytes, especially in the regeneration phase, showed a dose-dependent behavior (same level as the control for 10 and 25 R; and overshoot for 100 and 200 R; a gradual recovery for 1 and 2 kR; no mitosis for 4 and 8 kR). (author)

Arsenic-induced dose-dependent modulation of the NF-κB/IL-6 axis in thymocytes triggers differential immune responses

International Nuclear Information System (INIS)

Choudhury, Sreetama; Gupta, Payal; Ghosh, Sayan; Mukherjee, Sudeshna; Chakraborty, Priyanka; Chatterji, Urmi; Chattopadhyay, Sreya

2016-01-01

Highlights: • We for the first time explicitly show that arsenic exposure causes morphological damage to the thymus and results in heightened death of thymocytes. • Our data suggests that arsenic-induced apoptosis occurs due to increase in cellular oxidative and nitrosative stress. • We have for the first time established a non-classical role of NF-κB, correlating it with increase in FoxP3 expression. • The % of CD4+ CD25+ T cells were high and expression of FoxP3 has also increased at higher doses of arsenic indicating an nTreg bias. - Abstract: Arsenic contamination of drinking water is a matter of global concern. Arsenic intake impairs immune responses and leads to a variety of pathological conditions including cancer. In order to understand the intricate tuning of immune responses elicited by chronic exposure to arsenic, a mouse model was established by subjecting mice to different environmentally relevant concentrations of arsenic in drinking water for 30 days. Detailed study of the thymus, a primary immune organ, revealed arsenic-mediated tissue damage in both histological specimens and scanning electron micrographs. Analysis of molecular markers of apoptosis by Western blot revealed a dose-dependent activation of the apoptotic cascade. Enzymatic assays supported oxidative stress as an instigator of cell death. Interestingly, assessment of inflammatory responses revealed disparity in the NF-κB/IL-6/STAT3 axis, where it was found that in animals consuming higher amounts of arsenic NF-κB activation did not lead to the classical IL-6 upregulation response. This deviation from the canonical pathway was accompanied with a significant rise in numbers of CD4+ CD25+ FoxP3 expressing cells in the thymus. The cytokine profile of the animals exposed to higher doses of arsenic also indicated an immune-suppressed milieu, thus validating that arsenic shapes the immune environment in context to its dose of exposure and that at higher doses it leads to immune

Selection in the thymus: pathway divergence and the commitment to life or death

NARCIS (Netherlands)

Canté-Barrett, K.

2007-01-01

Positive and negative selection are processes specific to thymocytes and are crucial to establish a diverse, yet self-tolerant T cell repertoire. Millions of thymocytes each contain a unique T cell receptor (TCR) due to random rearrangement of TCR gene segments, creating immense diversity. However,

Experiment list: SRX099380 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available .7,8.5,497 GSM803108: Mi2beta Ikaros knockout chromatin source_name=mouse Ik knockout DP thymocytes || genet...ic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || chip antibody=h

Transient virus expression during murine leukemia induction by x-irradiation

International Nuclear Information System (INIS)

Haas, M.

1977-01-01

Most x-irradiation-induced thymomas in C57BL/6 mice are virus-free when assayed by immunofluorescence for the gs antigen (gsa) of murine leukemia virus (MuLV). Virus was induced transiently in bone marrow cells and later appeared in thymus cells. Six to 7 weeks post irradiation, thymocytes and bone marrow cells were MuLV gsa-negative and remained negative for the lifetime of most animals, whether or not they contracted overt leukemia. During the period when MuLV gsa-positive bone marrow cells were found, XC-positive syncytia-producing bone marrow cells were also found. Virus information was expressed, therefore, for a limited duration, long before any signs of leukemia in the animal were evident. MuLV gsa-positive thymocytes taken from mice 4 weeks after x-irradiation were cocultivated with a series of indicator cells. B-tropic virus, in addition to a xenotropic virus, was isolated from these cells. Ecotropic virus was not found in normal mouse thymocytes, in irradiated thymocytes a few days after termination of the X-irradiation sequence, or in most primary thymomas. All thymocytes produced only xenotropic virus in the cocultivation assays. Expression of the ecotropic virus was, therefore, transient, as assayed by immunofluorescence, XC syncytia formation, and virus isolation from MuLV gsa-positive thymus cells

Experiment list: SRX099395 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ,37.3,329 GSM803123: H3K27me3 Ikaros knockout chromatin preleukemic stage2 source_name=mouse Ik knockout DP ...thymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes

Experiment list: SRX099390 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ,38.3,343 GSM803118: H3K27me3 Ikaros knockout chromatin stageI source_name=mouse Ik knockout DP thymocytes |...| genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || developm

Experiment list: SRX099391 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 2.7,812 GSM803119: H3K9ac2 Ikaros knockout chromatin stageI source_name=mouse Ik knockout DP thymocytes || g...enetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || development

Experiment list: SRX099394 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 34.8,30309 GSM803122: H3K4me3 Ikaros knockout chromatin preleukemic stage2 source_name=mouse Ik knockout DP ...thymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes

Experiment list: SRX099396 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 0.5,3585 GSM803124: H3K9ac2 Ikaros knockout chromatin preleukemic stage2 source_name=mouse Ik knockout DP th...ymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes |

Experiment list: SRX099389 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 26.0,27537 GSM803117: H3K4me3 Ikaros knockout chromatin stageI source_name=mouse Ik knockout DP thymocytes |...| genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocytes || developm

Experiment list: SRX099397 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ,11.1,3164 GSM803125: H3K36me3 Ikaros knockout chromatin preleukemic stage2 source_name=mouse Ik knockout DP... thymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=DP thymocyte

The relative role of neutrophils and platelets in the local accumulation of circulating lymphocytes at sites of ionophore A23187 inoculation

Energy Technology Data Exchange (ETDEWEB)

Hayes, J.M.; Simmons, R.L. (Univ. of Pittsburgh, PA (USA))

1991-03-01

The early cellular infiltrate at inflammatory sites consists predominantly of neutrophils and cells of the monocyte/macrophage lineage. The mechanism by which circulating, unsensitized lymphocytes accumulate at sites of inflammation is unknown. The pattern of accumulation of 111indium-labeled circulating thymocytes in response to local injections of the ionophore A23187 was studied and compared with the pattern of (125)iodinated albumin accumulation as a measure of vascular permeability. The kinetics of thymocyte accumulation differed from those of vascular permeability. Sublethal total-body irradiation (750 rads) markedly decreased thymocyte accumulation but had little effect on vascular permeability. Irradiation of the local site alone had no effect. T lymphocyte, T lymphoblast, and platelet accumulation generally followed the same pattern as thymocytes. Intravenous injection of neutrophils, but not platelets, partially restored lymphocyte accumulation in vivo in irradiated mice via a pathway involving the circulating neutrophil, and seemed to be independent of changes in vascular permeability.

Photoperiodic modulation of local melatonin synthesis and its role in regulation of thymic homeostasis in Funambulus pennanti.

Science.gov (United States)

Gupta, Sameer; Haldar, Chandana

2016-12-01

The effect of photo-neuroendocrine system on the thymic (immune) functions is mediated by gonadal steroid and the pineal hormone melatonin. The present study explored the effect of photoperiod on the thymic melatonergic system and its role in protection of thymic T-cells from the testosterone induced seasonal oxidative stress and apoptosis. Exposure to long day-length (LD) was noted to decrease local (thymic) melatonin content and induce oxidative stress and apoptosis in the thymus. Increased peripheral level of testosterone upregulated the androgen receptor expression and, consequently reduced proliferation response of the thymocytes. Short day conditions (SD) however, reversed the effect of LD on the thymic physiology. Low level of testosterone was concomitant with diminished nitro-oxidative stress and decreased expression of redox sensitive factors (NF-κB, p53 and Bax/Bcl-2 ratio) in the thymus. SD retarded activation of caspase-3 resulting in procaspase-3 accumulation. Further, in vitro treatment of thymocytes with AR antagonist flutamide impaired the sensitivity of thymocytes to androgen and reversed the deleterious effects of testosterone on the proliferative and apoptotic responses of thymocytes. Therefore, it can be suggested that thymus derived melatonin protects thymic T-cells from testosterone induced seasonal oxidative stress, apoptosis and also acts as a potent paracrine factor for maintenance of redox status to ensure thymocyte survival. Copyright © 2015 Elsevier Inc. All rights reserved.

Structural changes in the regenerating rat thymus after irradiation

Energy Technology Data Exchange (ETDEWEB)

Fukumoto, Tetsuo; Wang, Yu-Hsueh; Hashimoto, Noriko; Tokuda, Nobuko; Sawada, Tomoo [Yamaguchi Univ., Ube (Japan). School of Medicine

1999-11-01

The structural changes of the rat thymus after irradiation were examined. Thymocytes regenerate rapidly after irradiation and the mechanism responsible for this rapid regeneration was examined analyzing vascular and immunohistochemical changes in the thymus. Following results were obtained: Vascular fine mesh works in the cortex were destroyed on day 3 after 6 Gy irradiation, while on day 5 these changes appeared to be restored to almost normal. Massive macrophage accumulations were observed in the cortex on day 3-5 after irradiation. This may be due to clean up the damaged thymocytes, although other possibility, as production of cytokines which may contribute to the rapid proliferation must be intensively examined. Immunohistochemical staining with anti MHC class II molecule showed relatively strong staining in the medulla compared to the cortex in the normal thymus, while this finding was reversed and cortex stained heavily compared to the medulla on day 5-7 after irradiation suggesting the importance of the cortical MHC class II positive thymic epithelial cells in regeneration of thymocytes. Anti FTS antibody stained relatively strongly in the irradiated and recovering thymus compared to the normal. These results may partly explain the abrupt proliferation of thymocytes after irradiation and further studies on cytokine message changes and thymic epithelial characterization responsible to produce the cytokines for the effective thymocyte proliteration are on the way of analysis. (author)

Role of radiation in chemical leukemogenesis in mice

International Nuclear Information System (INIS)

Kajitani, Takashi; Hamada, Katsutomo; Ito, Takaaki; Yokoro, Kenjiro

1980-01-01

Leukemia was induced in adult mice 6 to 8 months of age by the combined use of x-rays and N-nitrosoethylurea (NEU). Changes in thymocytes due to irradiation with x-rays were studied in order to determine the mechanism of leukemogenesis. The incidence of leukemia was 61.3% in mice given sucessive doses of NEU immediately after whole-body irradiation with x-rays and 18.8% in mice given successive doses of NEU 3 months after whole-body irradiation with x-rays. The thymus weight, the thymocyte count, the mitotic index in thymocytes, and the rate of DNA-synthesizing cells in the thymus decreased rapidly in both adult and young adult mice that underwent whole-body irradiation (400 R). The lowest values were observed 3 days after irradiation. The thymus weight and thymocyte count in the irradiated mice returned to within normal range 7 to 8 days after irradiation (the values were almost the same as those before irradiation). Rapid rebound phenomena were observed in the rate of DNA-synthesizing cells and mitotic index in the thymus 5 days after irradiation. The results suggest that there is a close relationship between the incidence of leukemia and thymocyte activity after irradiation with x-rays; that is, there is a large percentage of juvenile cells with energetic proliferation capacity. (Tsunoda, M.)

Intrathymic selection of NK1.1+α/β T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad

Science.gov (United States)

Iwabuchi, Chikako; Iwabuchi, Kazuya; Nakagawa, Ken-ichi; Takayanagi, Toshiaki; Nishihori, Hiroki; Tone, Saori; Ogasawara, Kazumasa; Good, Robert A.; Onoé, Kazunori

1998-01-01

Generation and negative selection of NK1.1+α/β T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice and Rag-1−/−/DO10 mice, which had been established by breeding and backcrossing between Rag-1−/− and DO10 mice. Almost all T cells from these mice were shown to bear Vα13/Vβ8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1+ Vα13/Vβ8.2+ thymocytes was generated in these mice. However, the actual cell number of both NK1.1+ and NK1.1− thymocytes in I-Ad/d mice (positive selecting background) was larger than that in I-Ab/d mice (negative selecting background). Markedly low but significant proportions of NK1.1+ Vα13/Vβ8.2+ cells were detected in the spleens from I-Ad/d and I-Ab/d mice. It was shown that the splenic NK1.1+ T cells of the I-Ab/d mice were anergized against stimulation through TCR. When (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice were given cOVA, extensive or intermediate elimination of NK1.1+α/βTCR+ thymocytes was induced in I-Ad/d or I-Ab/d mice, respectively. However, the clonal elimination was not as complete as that seen in the major NK1.1− thymocyte population. The present findings indicate that normal generation of NK1.1+α/βTCR+ thymocytes occurs in the absence of Vα14-Jα281 and that substantial negative selection operates on the NK1.1+α/βTCR+ cells. PMID:9653164

Absence of ERK5/MAPK7 delays tumorigenesis in Atm−/− mice

Science.gov (United States)

Rovira-Clavé, Xavier; Gamez, Celina Paola Vasquez; Soriano, Francesc X.; Reina, Manuel; Espel, Enric

2016-01-01

Ataxia-telangiectasia mutated (ATM) is a cell cycle checkpoint kinase that upon activation by DNA damage leads to cell cycle arrest and DNA repair or apoptosis. The absence of Atm or the occurrence of loss-of-function mutations in Atm predisposes to tumorigenesis. MAPK7 has been implicated in numerous types of cancer with pro-survival and pro-growth roles in tumor cells, but its functional relation with tumor suppressors is not clear. In this study, we show that absence of MAPK7 delays death due to spontaneous tumor development in Atm−/− mice. Compared with Atm−/− thymocytes, Mapk7−/−Atm−/− thymocytes exhibited an improved response to DNA damage (increased phosphorylation of H2AX) and a restored apoptotic response after treatment of mice with ionizing radiation. These findings define an antagonistic function of ATM and MAPK7 in the thymocyte response to DNA damage, and suggest that the lack of MAPK7 inhibits thymic lymphoma growth in Atm−/− mice by partially restoring the DNA damage response in thymocytes. PMID:27793024

Absence of ERK5/MAPK7 delays tumorigenesis in Atm-/- mice.

Science.gov (United States)

Granados-Jaén, Alba; Angulo-Ibáñez, Maria; Rovira-Clavé, Xavier; Gamez, Celina Paola Vasquez; Soriano, Francesc X; Reina, Manuel; Espel, Enric

2016-11-15

Ataxia-telangiectasia mutated (ATM) is a cell cycle checkpoint kinase that upon activation by DNA damage leads to cell cycle arrest and DNA repair or apoptosis. The absence of Atm or the occurrence of loss-of-function mutations in Atm predisposes to tumorigenesis. MAPK7 has been implicated in numerous types of cancer with pro-survival and pro-growth roles in tumor cells, but its functional relation with tumor suppressors is not clear. In this study, we show that absence of MAPK7 delays death due to spontaneous tumor development in Atm-/- mice. Compared with Atm-/- thymocytes, Mapk7-/-Atm-/- thymocytes exhibited an improved response to DNA damage (increased phosphorylation of H2AX) and a restored apoptotic response after treatment of mice with ionizing radiation. These findings define an antagonistic function of ATM and MAPK7 in the thymocyte response to DNA damage, and suggest that the lack of MAPK7 inhibits thymic lymphoma growth in Atm-/- mice by partially restoring the DNA damage response in thymocytes.

LKB1 mediates the development of conventional and innate T cells via AMP-dependent kinase autonomous pathways.

Directory of Open Access Journals (Sweden)

Marouan Zarrouk

Full Text Available The present study has examined the role of the serine/threonine kinase LKB1 in the survival and differentiation of CD4/8 double positive thymocytes. LKB1-null DPs can respond to signals from the mature α/β T-cell-antigen receptor and initiate positive selection. However, in the absence of LKB1, thymocytes fail to mature to conventional single positive cells causing severe lymphopenia in the peripheral lymphoid tissues. LKB1 thus appears to be dispensable for positive selection but important for the maturation of positively selected thymocytes. LKB1 also strikingly prevented the development of invariant Vα14 NKT cells and innate TCR αβ gut lymphocytes. Previous studies with gain of function mutants have suggested that the role of LKB1 in T cell development is mediated by its substrate the AMP-activated protein kinase (AMPK. The present study now analyses the impact of AMPK deletion in DP thymocytes and shows that the role of LKB1 during the development of both conventional and innate T cells is mediated by AMPK-independent pathways.

Elevation of oleate-activated phospholipase D activity during thymic atrophy

Science.gov (United States)

Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un

2002-01-01

Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188

77 FR 27508 - Self-Regulatory Organizations; New York Stock Exchange LLC; NYSE Amex LLC; Notice of Designation...

Science.gov (United States)

2012-05-10

..., Themis Trading LLC, dated October 17, 2011 (``Themis Letter''); Garret Cook, dated November 4, 2011 (``Cook Letter''); James Johannes, dated November 27, 2011 (``Johannes Letter''); Ken Voorhies, dated...''); Thomas Dercks, dated December 1, 2011 (``Dercks Letter''); Eric Swanson, Secretary, BATS Global Markets...

77 FR 12629 - Self-Regulatory Organizations; New York Stock Exchange LLC; NYSE Amex LLC; Notice of Filing of...

Science.gov (United States)

2012-03-01

..., Themis Trading LLC, dated October 17, 2011 (``Themis Letter''); Garret Cook, dated November 4, 2011 (``Cook Letter''); James Johannes, dated November 27, 2011 (``Johannes Letter''); Ken Voorhies, dated... (``UBS Letter''); Dr. Larry Paden, Bright Trading, dated December 1, 2011 (``Paden Letter''); Thomas...

Changes of some immune functions in combined radiation-burn injury in rats

International Nuclear Information System (INIS)

Yan Yongtang; Ran Xinze; Wei Shuqing

1991-01-01

The characteristics of some immune functions in radiation injury (6 Gy), burn injury (15%, III deg) and combined radiation-burn injury (CRBI) were studied in rats. The results showed that the functions of splenocytes and thymocytes in radiation injury group (RIG) were depressed more markedly 24-72 h after injury. The degree of thymocyte depression in burn injury group (BIG) was significantly lower than that in RIG and recovered more easily. The characteristics of the CRBI effects were as follows: (1) The combined depression effect on thymocytes in CRBI as compared with that in RIG was deeper and the recovery was slower. (2) The depression course of splenocytes was similar to that in RIG, but the depression degree in the early stage was significantly more heavy than that in RIG. (3) In the later stage of CRBI the level of recovery of T H cells was significantly lower than that in RIG. (4) Eschar-excision plus skin grafting at 24 h after combined injury was helpful for the recovery of thymocyte and splenocytes function. The results showed that the depression and recovery of immune functions in combined injury were closely related to the wound of burn

The mechanism of radiation-induced interphase death of lymphoid cells: A new hypothesis

International Nuclear Information System (INIS)

Eidus, L.K.; Korystov, Yu.N.; Dobrovinskaja, O.R.; Shaposhnikova, V.V.

1990-01-01

The interphase death of irradiated rat thymocytes depends on their concentration during postirradiation incubation. The kinetics of pycnosis and cell death determined with the trypan blue exclusion test in the samples with the highest cell concentration (1-2 x 10(7) cells/ml) is consistent with the data available in the literature, whereas the samples with the lowest concentration (2 x 10(5) cells/ml) undergo almost no pycnosis and death after irradiation with doses up to 50 Gy. On the basis of these results, we suggest a new mechanism of interphase death involving an interaction between irradiated thymocytes and the fraction of thymus cells possessing cytocidal activity. The observed correlation between the cytocidal activity and interphase death of thymocytes from animals of different ages favors our mechanism. It was found that the inhibitors which prevent the conjugation of killer cells and their targets do not influence interphase death, while the substances which block the secretion of cytotoxic factors or their action on the target membrane do protect from interphase death. Thus we suggest that the irradiation activates the killer cells to secrete some cytotoxic factors which induce pycnosis and interphase death of thymocytes

Phenotypic characterization of early events of thymus repopulation in radiation bone marrow chimeras

International Nuclear Information System (INIS)

Sharrow, S.O.; Singer, A.; Hammerling, U.; Mathieson, B.J.

1983-01-01

The phenotype of murine thymocytes repopulating the thymus of radiation bone marrow chimeras shortly after irradiation and bone marrow reconstitution was analyzed by immunofluorescence and flow microfluorometry. Thymuses in these chimeras, while essentially devoid of lymphoid cells at day 7, were repopulated by days 10 to 12 after irradiation. It was found that this initial repopulation arose from a radioresistant intrathymic precursor that expanded to an almost complete complement of host-type thymocytes. However, these host-derived thymocytes were unusual in that they were relatively deficient in Lyt 1+2- and peanut agglutinin ''dull'' cells as compared with normal thymocytes. Donor bone-marrow-derived cells first appeared in the irradiated chimeric thymuses between days 12 and 15 after irradiation and bone marrow transfer. By day 19, chimeric thymuses contained more than 98% donor cells. This course was identical for three chimeric combinations, each made across different genetic barriers. In contrast to the cells that populate the fetal thymus during normal ontogeny, the first donor bone-marrow-derived cells that can be detected within the irradiated chimeric thymuses already expressed phenotypically normal adult T cell subpopulations in that they contained significant numbers both of Lyt 1+2- and of Lyt 1+2+ thymocytes. Thus, the Lyt phenotype of donor cells that initially repopulate an adult thymus after irradiation is markedly different from the Lyt phenotype of cells that initially populate the fetal thymus. The differences between adult and fetal thymic development that are observed in radiation bone marrow chimeras may be important in our understanding of T cell differentiation in these animals

Immunohistological Analysis of the Jun Family and the Signal Transducers and Activators of Transcription in Thymus

Directory of Open Access Journals (Sweden)

Alexandra Papoudou-Bai

2015-01-01

Full Text Available The Jun family and the signal transducers and activators of transcription (STAT are involved in proliferation and apoptosis. Moreover, c-Jun and STAT3 cooperate to regulate apoptosis. Therefore, we used double immunostaining to investigate the immunotopographical distribution of phospho-c-Jun (p-c-Jun, JunB, JunD, p-STAT3, p-STAT5, and p-STAT6 in human thymus. JunD was frequently expressed by thymocytes with higher expression in medullary compared to cortical thymocytes. p-c-Jun was frequently expressed by cortical and medullary thymic epithelial cells (TEC and Hassall bodies (HB. p-STAT3 was frequently expressed by TEC with higher expression in cortical compared to medullary TEC and HB. p-c-Jun, JunB, p-STAT3, p-STAT5, and p-STAT6 were rarely expressed by thymocytes. JunB and JunD were expressed by rare cortical TEC with higher expression in medullary TEC. p-STAT5 and p-STAT6 were expressed by rare cortical and medullary TEC. Double immunostaining revealed p-c-Jun and JunD expression in rare CD11c positive dendritic cells. Our findings suggest a notable implication of JunD in the physiology of thymocytes and p-c-Jun and p-STAT3 in the physiology of TEC. The diversity of the immunotopographical distribution and the expression levels of p-c-Jun, JunB, JunD, p-STAT3, p-STAT5, and p-STAT6 indicates that they are differentially involved in the differentiation of TEC, thymocytes, and dendritic cells.

Chromatin degradation under the effect of differentiation inductors and γ-radiation on thymus lymphocytes in vitro

International Nuclear Information System (INIS)

Soldatenkov, V.A.; Sorokina, N.I.; Filippovich, I.V.

1985-01-01

Chemical inductors of differentiation were shown to cause chromatin degradation in thymus lymphocytes. This process was prevented by the protein synthesis inhibitors. The fragments formed after the effect of chemical differentiation inductors on thymocytes were fully identical to chromatin internucleosome degradation products formed in the exposed cells. Chromatin degradation under the effect of chemical differentiation inductors was most pronounced in a more radiosensitive thymocyte fraction

First Detection of Water Ice and Organics on an Asteroid: A Possible Link to the Origin of Earth's Water

Science.gov (United States)

Hargrove, Kelsey D.; Campins, H.; Pinilla-Alonso, N.; Howell, E. S.; Kelley, M. S.; Licandro, J.; Mothédiniz, T.; Fernández, Y.; Ziffer, J.

2010-05-01

We report the detection of water ice and organics on the surface of asteroid 24 Themis. Our rotationally-resolved infrared (2-4 µm) spectra of this asteroid indicate that the ice and organics are widespread on its surface. The spectral difference with other asteroids observed in the same manner, makes 24 Themis unique so far. Our identification of water ice and organic compounds on this asteroid agrees with independent results (Rivkin and Emery 2010). At first glance, the presence of any surface ice on 24 Themis, particularly over a significant fraction of its surface, is puzzling because of the instability for exposed water ice at Themis's heliocentric distance ( 3.2 AU). Nevertheless, there are several possible sources for this unstable ice and identifying them is likely to be diagnostic of other processes on primitive asteroids. The presence of water ice on 24 Themis supports the idea that ice sublimation drives the cometary activity in two small members of the Themis dynamical family, labeled "Main Belt comets” by Hsieh and Jewitt (2006). It also helps to address other relevant questions, such as, how abundant is water ice in the outer asteroid belt and where was the "snow” line when the solar system formed? The answers to these questions could transform current views of primitive asteroids, delivery of water and organic molecules to Earth, and models of Solar System formation. This research was published in the April 29, 2010 issue of the journal Nature. Hargrove and Campins are visiting astronomers at the Infrared Telescope Facility (IRTF), which is operated by the University of Hawaii under Cooperative Agreement no. NCC 5-538 with the National Aeronautics and Space Administration

A cytocidal tissue kallikrein isolated from mouse submandibular glands.

Science.gov (United States)

Murakami, K; Ikigai, H; Nagumo, N; Tomita, M; Shimamura, T

1989-11-06

A cytocidal factor against mouse thymocytes was purified from the submandibular glands of female BALB/c mice using Sephadex G-50 gel filtration chromatography and reverse-phase HPLC. SDS-PAGE and amino acid sequence analysis revealed that the cytocidal factor was mouse glandular kallikrein (mGK)-6. mGK-6 showed an optimal enzyme activity at pH 10 and a cytocidal activity against thymocytes in a dose-dependent manner.

Expression of T cell antigen receptor genes in the thymus of irradiated mice after bone marrow transplantation

International Nuclear Information System (INIS)

Matsuzaki, G.; Yoshikai, Y.; Kishihara, K.; Nomoto, K.

1988-01-01

Sequential appearance of the expression of T cell antigen receptor genes was investigated in the thymus of irradiated mice at the early stage after transplantation of Thy-1 congeneic H-2 compatible allogeneic bone marrow cells. The first cells to repopulate the thymus on day 7 after bone marrow transplantation were intrathymic radioresistant T cell precursors, which expanded mainly to CD4+CD8+ host-type thymocytes by day 14. A high level of gamma gene expression but a much reduced level of alpha and beta gene expression were detected in the host-type thymocytes on day 7. During regeneration of these cells, gamma-chain messages fell to low level and alpha and beta mRNA levels increased. The thymus of the recipients began to be repopulated by donor-derived T cells about 2 wk after bone marrow transplantation and was almost completely replaced by the third week. An ordered expression of gamma then beta and alpha-chain gene transcript was also observed in the donor-type thymocytes at the early stage after bone marrow transplantation. The use of thymocytes at early stage in whole-body irradiated bone marrow chimera provides a pertinent source for investigating the molecular mechanism of T cell differentiation in adult thymus

Matriptase/MT-SP1 is required for postnatal survival, epidermal barrier function, hair follicle development, and thymic homeostasis

DEFF Research Database (Denmark)

List, Karin; Haudenschild, Christian C; Szabo, Roman

2002-01-01

of Matriptase/MT-SP1 also seriously affected hair follicle development resulting in generalized follicular hypoplasia, absence of erupted vibrissae, lack of vibrissal hair canal formation, ingrown vibrissae, and wholesale abortion of vibrissal follicles. Furthermore, Matriptase/MT-SP1-deficiency resulted...... in dramatically increased thymocyte apoptosis, and depletion of thymocytes. This study demonstrates that Matriptase/MT-SP1 has pleiotropic functions in the development of the epidermis, hair follicles, and cellular immune system....

Can a Proper T-Cell Development Occur in an Altered Thymic Epithelium? Lessons From EphB-Deficient Thymi

Directory of Open Access Journals (Sweden)

Juan José Muñoz

2018-04-01

Full Text Available For a long time, the effects of distinct Eph tyrosine kinase receptors and their ligands, ephrins on the structure, immunophenotype, and development of thymus and their main cell components, thymocytes (T and thymic epithelial cells (TECs, have been studied. In recent years, the thymic phenotype of mutant mice deficient in several Ephs and ephrins B has been determined. Remarkably, thymic stroma in these animals exhibits important defects that appear early in ontogeny but little alterations in the proportions of distinct lymphoid cell populations. In the present manuscript, we summarize and extend these results discussing possible mechanisms governing phenotypical and functional thymocyte maturation in an absence of the critical T–TEC interactions, concluding that some signaling mediated by key molecules, such as MHCII, CD80, β5t, Aire, etc. could be sufficient to enable a proper maturation of thymocytes, independently of morphological alterations affecting thymic epithelium.

RasGRP1, but not RasGRP3, is required for efficient thymic β-selection and ERK activation downstream of CXCR4.

Directory of Open Access Journals (Sweden)

Dominic P Golec

Full Text Available T cell development is a highly dynamic process that is driven by interactions between developing thymocytes and the thymic microenvironment. Upon entering the thymus, the earliest thymic progenitors, called CD4(-CD8(- 'double negative' (DN thymocytes, pass through a checkpoint termed "β-selection" before maturing into CD4(+CD8(+ 'double positive' (DP thymocytes. β-selection is an important developmental checkpoint during thymopoiesis where developing DN thymocytes that successfully express the pre-T cell receptor (TCR undergo extensive proliferation and differentiation towards the DP stage. Signals transduced through the pre-TCR, chemokine receptor CXCR4 and Notch are thought to drive β-selection. Additionally, it has long been known that ERK is activated during β-selection; however the pathways regulating ERK activation remain unknown. Here, we performed a detailed analysis of the β-selection events in mice lacking RasGRP1, RasGRP3 and RasGRP1 and 3. We report that RasGRP1 KO and RasGRP1/3 DKO deficient thymi show a partial developmental block at the early DN3 stage of development. Furthermore, DN3 thymocytes from RasGRP1 and RasGRP1/3 double knock-out thymi show significantly reduced proliferation, despite expression of the TCRβ chain. As a result of impaired β-selection, the pool of TCRβ(+ DN4 is significantly diminished, resulting in inefficient DN to DP development. Also, we report that RasGRP1 is required for ERK activation downstream of CXCR4 signaling, which we hypothesize represents a potential mechanism of RasGRP1 regulation of β-selection. Our results demonstrate that RasGRP1 is an important regulator of proliferation and differentiation at the β-selection checkpoint and functions downstream of CXCR4 to activate the Ras/MAPK pathway.

Intrathymic T cell differentiation in radiation bone marrow chimeras and its role in T cell emigration to the spleen. An immunohistochemical study

International Nuclear Information System (INIS)

Hirokawa, K.; Sado, T.; Kubo, S.; Kamisaku, H.; Hitomi, K.; Utsuyama, M.

1985-01-01

Immunohistochemical studies were made on the regeneration of T cells of host- and donor-type in the thymus and spleen of radiation bone marrow chimeras by using B10- and B10.BR-Thy-1 congenic mice. In Thy-1 congenic chimeras, thymocytes of donor bone marrow origin, were first recognized at day 7, when the thymus involuted to the smallest size after the irradiation. The thymocytes of donor-type then proliferated exponentially, showing a slightly faster rate when higher doses of bone marrow cells were used for reconstitution, reaching a level of 100 million by day 17 and completely replacing the cortical thymocytes of host origin by day 21. The replacement of medullary thymocytes from host- to donor-type occurred gradually between days 21 and 35, after the replacement in the cortex was completed. In the spleen, about 1 million survived cells were recovered at day 3 after the irradiation, and approximately 60% of them were shown to be host-type T cells that were observed in the white pulp areas. The host-type T cells in the spleen increased gradually after day 10, due to the influx of host-type T cells from the regenerating thymus. Thus a pronounced increase of T cells of host-type was immunohistochemically observed in the splenic white pulp between days 21 and 28, when thymocytes of host-type were present mainly in the thymic medulla. These host-type T cells were shown to persist in the spleen for a long time, as long as 420 days after the treatment. Phenotypically, they were predominantly Lyt-1+2+ when examined at day 28, but 5 mo later, they were about 50% Lyt-1+2+ and 50% Lyt-1+2-

Positive and negative regulation of V(D)J recombination by the E2A proteins.

Science.gov (United States)

Bain, G; Romanow, W J; Albers, K; Havran, W L; Murre, C

1999-01-18

A key feature of B and T lymphocyte development is the generation of antigen receptors through the rearrangement and assembly of the germline variable (V), diversity (D), and joining (J) gene segments. However, the mechanisms responsible for regulating developmentally ordered gene rearrangements are largely unknown. Here we show that the E2A gene products are essential for the proper coordinated temporal regulation of V(D)J rearrangements within the T cell receptor (TCR) gamma and delta loci. Specifically, we show that E2A is required during adult thymocyte development to inhibit rearrangements to the gamma and delta V regions that normally recombine almost exclusively during fetal thymocyte development. The continued rearrangement of the fetal Vgamma3 gene segment in E2A-deficient adult thymocytes correlates with increased levels of Vgamma3 germline transcripts and increased levels of double-stranded DNA breaks at the recombination signal sequence bordering Vgamma3. Additionally, rearrangements to a number of Vgamma and Vdelta gene segments used predominantly during adult development are significantly reduced in E2A-deficient thymocytes. Interestingly, at distinct stages of T lineage development, both the increased and decreased rearrangement of particular Vdelta gene segments is highly sensitive to the dosage of the E2A gene products, suggesting that the concentration of the E2A proteins is rate limiting for the recombination reaction involving these Vdelta regions.

Dayside magnetopause transients correlated with changes of the magnetosheath magnetic field orientation

Directory of Open Access Journals (Sweden)

O. Tkachenko

2011-04-01

Full Text Available The paper analyses one long-term pass (26 August 2007 of the THEMIS spacecraft across the dayside low-latitude magnetopause. THEMIS B, serving partly as a magnetosheath monitor, observed several changes of the magnetic field that were accompanied by dynamic changes of the magnetopause location and/or the structure of magnetopause layers observed by THEMIS C, D, and E, whereas THEMIS A scanned the inner magnetosphere. We discuss the plasma and the magnetic field data with motivation to identify sources of observed quasiperiodic plasma transients. Such events at the magnetopause are usually attributed to pressure pulses coming from the solar wind, foreshock fluctuations, flux transfer events or surface waves. The presented transient events differ in nature (the magnetopause surface deformation, the low-latitude boundary layer thickening, the crossing of the reconnection site, but we found that all of them are associated with changes of the magnetosheath magnetic field orientation and with enhancements or depressions of the plasma density. Since these features are not observed in the data of upstream monitors, the study emphasizes the role of magnetosheath fluctuations in the solar wind-magnetosphere coupling.

Modulation of cisplatin-induced reactive oxygen species production by fullerene C(60 in normal and transformed lymphoid cells

Directory of Open Access Journals (Sweden)

D. V. Franskevych

2016-02-01

Full Text Available The early response of normal (Wistar rat thymocytes and transformed (mice lymphoid leukemia L1210 cells to treatment with anticancer drug cisplatin or to combined treatment with cisplatin and carbon nanostructure fullerene C60 was studied. We demonstrated with fluorescent probes DCFH-DA and TMRE that cisplatin at concentration 1 μg/ml induced reactive oxygen species (ROS production and decreased the value of mitochondrial membrane potential in both cell types. The combined treatment with cisplatin (1 μg/ml and fullerene C60 (7.2 μg/ml was shown to be followed by oppositely directed modulation of ROS production in thymocytes and L1210 cells. Cisplatin-induced ROS production was intensified in L1210 cells, while in thymocytes it was decreased. It is supposed that the different effects of combined treatment are associated with peculiarities of fullerene C60 accumulation and localization in normal and cancer cells.

Colored Chaos

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 7 May 2004 This daytime visible color image was collected on May 30, 2002 during the Southern Fall season in Atlantis Chaos. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation. Image information: VIS instrument. Latitude -34.5, Longitude 183.6 East (176.4 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D

Auream Chaos

Science.gov (United States)

2005-01-01

[figure removed for brevity, see original site] The THEMIS VIS camera is capable of capturing color images of the Martian surface using five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from using multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation. This false color image was collected during Southern Fall and shows part of the Aureum Chaos. Image information: VIS instrument. Latitude -3.6, Longitude 332.9 East (27.1 West). 35 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS

Heterogenous populations of cytotoxic cells in the peritoneal cavity of BALB/c mice immunized with allogeneic EL4 leukemia cells

International Nuclear Information System (INIS)

Zighelboim, J.; Bonavida, B.; Fahey, J.L.

1974-01-01

Adherent cells, presumably macrophages, obtained from the peritoneal cavity shortly after rejection of the allogeneic leukemia EL4, produced effective cell-mediated cytotoxicity (CMC) in vitro. These cytotoxic cells were sensitive to anti-macrophage serum and resistant to anti-thymocyte serum and 10,000 roentgen irradiation. In contrast, a second population of specifically cytotoxic cells were nonadherent, sensitive to x-rays and anti-thymocyte serum, but not to anti-macrophage serum. The two cell populations had a cooperative cytotoxic effect in vitro against allogeneic tumor cells

Prenatal exposure to TCDD triggers significant modulation of microRNA expression profile in the thymus that affects consequent gene expression.

Directory of Open Access Journals (Sweden)

Narendra P Singh

Full Text Available MicroRNAs (miRs are a class of small RNAs that regulate gene expression. There are over 700 miRs encoded in the mouse genome and modulate most of the cellular pathways and functions by controlling gene expression. However, there is not much known about the pathophysiological role of miRs. TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin, an environmental contaminant is well known to induce severe toxicity (acute and chronic with long-term effects. Also, in utero exposure of fetus to TCDD has been shown to cause thymic atrophy and alterations in T cell differentiation. It is also relevant to understand "the fetal basis of adult disease" hypothesis, which proposes that prenatal exposure to certain forms of nutritional and environmental stress can cause increased susceptibility to clinical disorders later in life. In the current study, therefore, we investigated the effects of prenatal exposure to TCDD on miR profile in fetal thymocytes and searched for their possible role in causing thymic atrophy and alterations in the expression of apoptotic genes.miR arrays of fetal thymocytes post exposure to TCDD and vehicle were performed. Of the 608 mouse miRs screened, 78 miRs were altered more than 1.5 fold and 28 miRs were changed more than 2 fold in fetal thymocytes post-TCDD exposure when compared to vehicle controls. We validated the expression of several of the miRs using RT-PCR. Furthermore, several of the miRs that were downregulated contained highly complementary sequence to the 3'-UTR region of AhR, CYP1A1, Fas and FasL. Also, the Ingenuity Pathway Analysis software and database was used to analyze the 78 miRs that exhibited significant expression changes and revealed that as many as 15 pathways may be affected.These studies revealed that TCDD-mediated alterations in miR expression may be involved in the regulation of its toxicity including cancer, hepatic injury, apoptosis, and cellular development.

Influence of age on the proliferation and peripheralization of thymic T cells

International Nuclear Information System (INIS)

Hirokawa, K.; Utsuyama, M.; Katsura, Y.; Sado, T.

1988-01-01

Bone marrow cells obtained from B10.Thy-1.1 mice (H-2b, Thy-1.1) were injected directly into the thymus of C57BL/6 mice (H-2b,Thy 1.2) of various ages. Thymocyte precursors in the injected donor-bone marrow cells could proliferate in the thymic microenvironment in the following manner: first, preferentially proliferating into the subcapsular cortex; and second, spreading to the whole layer of the cortex, a portion of them gradually moving into the medulla. The proliferation of donor-type thymocytes was most pronounced when intrathymic injection of bone marrow cells (ITB) was performed in newborn mice and especially prominent in week-old mice; it took approximately ten weeks for donor-type thymocytes to finish the whole course of proliferation, differentiation, and emigration to the periphery. When ITB was performed in mice 4 weeks of age and older, the proliferation of donor-type thymocytes was retarded at onset, less pronounced in magnitude, and disappeared earlier. Emigration of donor-type T cells from the thymus to the peripheral lymphoid tissues occurred most rapidly when ITB was performed in newborn mice, and these T cells continued to reside thereafter in the peripheral lymphoid tissues. However, when ITB was performed in mice 4 weeks of age and older, the number of emigrated T cells in the spleen decreased (about a tenth of that in newborn mice) and, moreover, these T cells resided only transiently in the spleen. It was suggested that T cells emigrating from the thymus of mice from newborn to 2 weeks of age are long-lived, whereas those from the thymus in mice 4 weeks of age and older are short-lived. However, when 4-week-old young adult mice were treated by irradiation or hydrocortisone, the thymic capacity was enhanced in terms of proliferation and peripheralization of thymocytes, and emigrated T cells became long-lived

The Wnt Signaling Antagonist Kremen1 is Required for Development of Thymic Architecture

Directory of Open Access Journals (Sweden)

Masako Osada

2006-01-01

Full Text Available Wnt signaling has been reported to regulate thymocyte proliferation and selection at several stages during T cell ontogeny, as well as the expression of FoxN1 in thymic epithelial cells (TECs. Kremen1 (Krm1 is a negative regulator of the canonical Wnt signaling pathway, and functions together with the secreted Wnt inhibitor Dickkopf (Dkk by competing for the lipoprotein receptor-related protein (LRP-6 co-receptor for Wnts. Here krm1 knockout mice were used to examine krm1 expression in the thymus and its function in thymocyte and TEC development. krm1 expression was detected in both cortical and medullary TEC subsets, as well as in immature thymocyte subsets, beginning at the CD25+CD44+ (DN2 stage and continuing until the CD4+CD8+(DP stage. Neonatal mice show elevated expression of krm1 in all TEC subsets. krm1− / − mice exhibit a severe defect in thymic cortical architecture, including large epithelial free regions. Much of the epithelial component remains at an immature Keratin 5+ (K5 Keratin 8+(K8 stage, with a loss of defined cortical and medullary regions. A TOPFlash assay revealed a 2-fold increase in canonical Wnt signaling in TEC lines derived from krm1− / − mice, when compared with krm1+ / + derived TEC lines. Fluorescence activated cell sorting (FACS analysis of dissociated thymus revealed a reduced frequency of both cortical (BP1+EpCAM+ and medullary (UEA-1+ EpCAMhi epithelial subsets, within the krm1− / − thymus. Surprisingly, no change in thymus size, total thymocyte number or the frequency of thymocyte subsets was detected in krm1− / − mice. However, our data suggest that a loss of Krm1 leads to a severe defect in thymic architecture. Taken together, this study revealed a new role for Krm1 in proper development of thymic epithelium.

Antigen-primed helper T cell function in CBA/N mice is radiosensitive

International Nuclear Information System (INIS)

Phillips, N.E.; Campbell, P.A.

1981-01-01

CBA/N mice have an X-linked immunodeficiency that includes a deficient humoral response to sheep red blood cells (SRBC). In order to study the cellular mechanisms of this deficiency we have examined helper T cell function to SRBC in an adoptive transfer system by using 2 different sources of helper T cells. When thymocytes were used as the source of helper T cell precursors in an adoptive transfer system, CBA/N thymocytes were as effective as CBA/Ca thymocytes in inducing CBA/Ca bone marrow cells to develop into both direct and indirect anti-SRBC plaque-forming cells (PFC). However, when SRBC-primed, irradiated recipient mice were used as the source of helper T cells, primed and irradiated CBA/N recipiets developed significantly fewer direct and indirect anti-SRBC PFC than similarly treated CBA/CA recipients when reconstituted with CBA/Ca bone marrow cells and challenged with SRBC. We conclude that antigen-primed helper T cell function in CBA/N mice is radiosensitive. Possible reasons for this are evaluated and discussed

The thioredoxin-1 system is essential for fueling DNA synthesis during T-cell metabolic reprogramming and proliferation.

Science.gov (United States)

Muri, Jonathan; Heer, Sebastian; Matsushita, Mai; Pohlmeier, Lea; Tortola, Luigi; Fuhrer, Tobias; Conrad, Marcus; Zamboni, Nicola; Kisielow, Jan; Kopf, Manfred

2018-05-10

The thioredoxin-1 (Trx1) system is an important contributor to cellular redox balance and is a sensor of energy and glucose metabolism. Here we show critical c-Myc-dependent activation of the Trx1 system during thymocyte and peripheral T-cell proliferation, but repression during T-cell quiescence. Deletion of thioredoxin reductase-1 (Txnrd1) prevents expansion the CD4 - CD8 - thymocyte population, whereas Txnrd1 deletion in CD4 + CD8 + thymocytes does not affect further maturation and peripheral homeostasis of αβT cells. However, Txnrd1 is critical for expansion of the activated T-cell population during viral and parasite infection. Metabolomics show that TrxR1 is essential for the last step of nucleotide biosynthesis by donating reducing equivalents to ribonucleotide reductase. Impaired availability of 2'-deoxyribonucleotides induces the DNA damage response and cell cycle arrest of Txnrd1-deficient T cells. These results uncover a pivotal function of the Trx1 system in metabolic reprogramming of thymic and peripheral T cells and provide a rationale for targeting Txnrd1 in T-cell leukemia.

Control of IgE and IgGl antibody production in mice

International Nuclear Information System (INIS)

De Macedo, M.S.; Braga, F.; Mota, I.

1976-01-01

The production of IgE and IgCl was studied in untreated, thymectomized, splenectomized, anti-thymocyte serum-treated, or sublethally X-irradiated mice. Dinitrophenyl, Ascaris, and ovalbumin were used as antigens, and aluminum hydroxide was used as adjuvant. A suppression of IgE production was observed in adult thymectomized mice, although the kinetic pattern of the antibody response was the same as in control animals. IgGl antibody production was not affected by thymectomy. Splenectomy did not change either IgE or IgGl production. A single dose of rabbit antithymocyte serum (ATS) given 8 days after immunization inhibited IgE antibody production. The effect of ATS was dose dependent and also varied with the amount of antigen used, the immune response to high doses being more susceptible to the effect of ATS. No alteration in IgGl production was caused by ATS even when IgE antibody formation was completely inhibited. When preceding immunization, sublethal irradiation enhanced IgE antibody formation and partially suppressed IgGl production; applied after immunization, irradiation caused an enhancement of IgE production which was inversely proportional to the interval elapsed between the two procedures. On the other hand, the IgGl antibody production was fairly resistant to the same treatment. The results suggest a clearcut separation between the mechanisms regulating IgE and IgGl production in mice

Deficiency in early development of the thymus-dependent cells in irradiation chimeras attributable to recipient's environment

International Nuclear Information System (INIS)

Iwabuchi, C.; Iwabuchi, K.; Kobayashi, S.; Ogasawara, K.; Negishi, I.; Wang, B.Y.; Wambua, P.P.; Arase, H.; Fukushi, N.; Itoh, Y.

1991-01-01

Bone marrow chimeras were prepared using reciprocal combinations of AKR and C3H mice. When C3H mice were recipients, the number of thymocytes recoverable from such chimeras (C3H recipient chimeras) was small as compared with that from chimeras for which AKR mice were used as recipients (AKR recipient chimeras) regardless of donor strain. The thymocytes from C3H recipient chimeras showed a profound deficiency in generating proliferative responses to stimulation by anti-CD3 mAb (2C11) or anti-TCR (alpha, beta) mAb (H57-597), even though the expression of CD3 and TCR molecules fell within the same range as that in AKR recipient chimeras. Furthermore, after stimulation with immobilized 2C11, the proportion of IL-2R+ cells in the thymocytes from C3H recipient chimeras was much less than that in AKR recipient chimeras. However, no significant difference in proliferative responses to 2C11 plus PMA, in influx of Ca2+ after stimulation with 2C11 or IL-2 production in response to 2C11 plus PMA or PMA plus A23187 was demonstrated between C3H and AKR recipient chimeras. These findings suggest that the thymocytes from C3H recipient chimeras have a deficiency in the signal transduction system as compared with chimeras for which AKR mice are the recipients. The thymic stromal component involved in this difference in the C3H recipient chimeras is discussed

Lunar and Planetary Science XXXV: Mars: Remote Sensing and Terrestrial Analogs

Science.gov (United States)

2004-01-01

The session "Mars: Remote Sensing and Terrestrial Analogs" included the following:Physical Meaning of the Hapke Parameter for Macroscopic Roughness: Experimental Determination for Planetary Regolith Surface Analogs and Numerical Approach; Near-Infrared Spectra of Martian Pyroxene Separates: First Results from Mars Spectroscopy Consortium; Anomalous Spectra of High-Ca Pyroxenes: Correlation Between Ir and M ssbauer Patterns; THEMIS-IR Emissivity Spectrum of a Large Dark Streak near Olympus Mons; Geomorphologic/Thermophysical Mapping of the Athabasca Region, Mars, Using THEMIS Infrared Imaging; Mars Thermal Inertia from THEMIS Data; Multispectral Analysis Methods for Mapping Aqueous Mineral Depostis in Proposed Paleolake Basins on Mars Using THEMIS Data; Joint Analysis of Mars Odyssey THEMIS Visible and Infrared Images: A Magic Airbrush for Qualitative and Quantitative Morphology; Analysis of Mars Thermal Emission Spectrometer Data Using Large Mineral Reference Libraries ; Negative Abundance : A Problem in Compositional Modeling of Hyperspectral Images; Mars-LAB: First Remote Sensing Data of Mineralogy Exposed at Small Mars-Analog Craters, Nevada Test Site; A Tool for the 2003 Rover Mini-TES: Downwelling Radiance Compensation Using Integrated Line-Sight Sky Measurements; Learning About Mars Geology Using Thermal Infrared Spectral Imaging: Orbiter and Rover Perspectives; Classifying Terrestrial Volcanic Alteration Processes and Defining Alteration Processes they Represent on Mars; Cemented Volcanic Soils, Martian Spectra and Implications for the Martian Climate; Palagonitic Mars: A Basalt Centric View of Surface Composition and Aqueous Alteration; Combining a Non Linear Unmixing Model and the Tetracorder Algorithm: Application to the ISM Dataset; Spectral Reflectance Properties of Some Basaltic Weathering Products; Morphometric LIDAR Analysis of Amboy Crater, California: Application to MOLA Analysis of Analog Features on Mars; Airborne Radar Study of Soil Moisture at

Mechanism of suppressive effect of low dose radiation on cancer cell dissemination in mice

International Nuclear Information System (INIS)

Fu Haiqing; Li Xiuyi; Chen Yubing; Zhang Yingchun; Liu Shuzheng

1997-01-01

Influence of low dose radiation on immunity in C57 BL/6 mice injected with cancer cells was studied. In mice given 75 mGy WBI 24 h before injection of Lewis lung carcinoma cells or B 16 melanoma cells, the percentage of S-phase thymocytes and CD 3+ thymocytes, the splenic NK cell activity, IL-2 secretion and γIFN secretion were found to be potentiated 2∼8 day after irradiation in comparison with the sham-irradiation mice. The results suggest that low dose radiation might suppress cancer cell dissemination via the enhancement of immune reactivity

Physical Properties of the MER and Beagle II Landing Sites on Mars

Science.gov (United States)

Jakosky, B. M.; Pelkey, S. M.; Mellon, M. T.; Putzig, N.; Martinez-Alonso, S.; Murphy, N.; Hynek, B.

2003-12-01

The ESA Beagle II and the NASA Mars Exploration Rover spacecraft are scheduled to land on the martian surface in December 2003 and January 2004, respectively. Mission operations and success depends on the physical properties of the surfaces on which they land. Surface structural characteristics such as the abundances of loose, unconsolidated fine material, of fine material that has been cemented into a duricrust, and of rocks affect the ability to safely land and to successfully sample and traverse the surface. Also, physical properties affect surface and atmospheric temperatures, which affect lander and rover functionality. We are in the process of analyzing surface temperature information for these sites, derived from MGS TES and Odyssey THEMIS daytime and nighttime measurements. Our approach is to: (i) remap thermal inertia using TES data at ~3-km resolution, to obtain the most complete coverage possible; (ii) interpret physical properties from TES coverage in conjunction with other remote-sensing data sets; (iii) map infrared brightness using daytime and nighttime THEMIS data at 100-m resolution, and do qualitative analysis of physical properties and processes; and (iv) derive thermal inertia from THEMIS nighttime data in conjunction with daytime albedo measurements derived from TES, THEMIS, and MOC observations. In addition, we will use measured temperatures and derived thermal inertia to predict surface temperatures for the periods of the missions.

Cre-/IoxP-Mediated Recombination between the SIL and SCL Genes Leads to a Block in T-Cell Development at the CD4-CD8- to CD4+CD8+ Transition

Directory of Open Access Journals (Sweden)

Yue Cheng

2007-04-01

Full Text Available In the most common form of stem cell leukemia (SCL gene rearrangement, an interstitial deletion of 82 kb brings SCL under the control of regulatory elements that normally govern expression of the ubiquitously expressed SCL interrupting locus (SIL gene, which is located directly upstream of SCL. To investigate the effect of this fusion in a mouse model, a bacterial artificial chromosome (BAC clone containing both human SIL and SCL genes was isolated, and IoxP sites were inserted into intron 1 of both the SIL and SCL genes, corresponding to the sites at which recombination occurs in human T-cell acute lymphocytic leukemia patients. This BAC clone was used to generate transgenic SILIoxloxSCL mice. These transgenic mice were subsequently bred to Lck-Cre mice that express the Cre recombinase specifically in the thymus. The BAC transgene was recombined between the two IoxP sites in over 50% of the thymocytes from SILIoxloxSCL/Cre double-transgenic mice, bringing the SCL gene under the direct control of SIL regulatory elements. Aberrant SCL gene expression in the thymus was verified by reverse transcription- polymerase chain reaction. Using FACS analysis, we found that mice carrying both SILIoxloxSCL and Cre transgenes have increased CD4-/CD8- thymocytes compared with transgenenegative mice. In the spleen, these transgenic mice show a marked reduction in the number of mature CD4+ or CD8+ cells. These results demonstrate that conditional activation of SCL under control of SIL regulatory elements can impair normal T-cell development.

Immunosuppressive effect of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through the inhibition of T-lymphocyte proliferation and IL-2 production

International Nuclear Information System (INIS)

Yun, Cheol-Heui; Son, Chang Gue; Jung, Uhee; Han, Seung Hyun

2006-01-01

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the predominant heterocyclic amine formed in cooked meat and fish and causes cancers in the colon, the mammary glands, and the lymphoid organs. In the present study, we investigated the immunological impact of PhIP using thymocytes isolated from Balb/c mice and a murine thymocyte-derived cell line, EL4. Treatment of the thymocytes with PhIP moderately inhibited T-cell mitogen-induced cell proliferation and interleukin (IL)-2 secretion. Reverse transcription-polymerase chain reaction (RT-PCR) analysis demonstrated that PhIP attenuated IL-2 mRNA expression in the thymocytes and EL4 cells stimulated with phytohemagglutinin (PHA) plus phorbol 12-myristate 13-acetate (PMA). In vitro transient transfection assay using a reporter gene construct containing IL-2 promoter showed that the decrease in the steady-state IL-2 mRNA level by PhIP is partially due to the attenuation of IL-2 mRNA synthesis at the transcriptional level. Furthermore, an electrophoretic mobility shift assay showed that PhIP inhibited DNA binding activity of nuclear factor for immunoglobulin κ chain in B cells (NF-κB), activator protein-1 (AP-1) and nuclear factor of activated T cells (NF-AT), which are known to be responsible for IL-2 transcriptional activation. Concomitantly, PhIP inhibited the PMA/PHA-induced generation of reactive oxygen species (ROS) involved in activation of the transcription factors. These results suggest that PhIP has potential immunosuppressive effects by inhibiting T-cell proliferation and IL-2 expression through down regulation of ROS generation and thereby inhibiting NF-κB, AP-1 and NF-AT activation

Interferon production and immune response induction in pathogenic rabies virus-infected mice

Energy Technology Data Exchange (ETDEWEB)

Marcovistz, R; Leal, E C; De Souza Matos, D C [Departamento de Immunologia, Instituto Oswaldo Cruz, Caixa Postal 926, 21045 Rio de Janeiro (Brazil); Tsiang, H [Service Rage, Istitut Pasteur, Paris (France)

1994-08-01

Pathogenic parental rabies virus strain CVS (challenge virus standard) and its apathogenic variant RV194-2 were shown to differ in their ability to induce interferon (IFN) and immune response of the host. After intracerebral inoculation. IFN and antibody production was higher in the RV194-2 virus-infected mice than in the CVS infection. The enhancement of 2-5A synthetase activity, an IFN-mediated enzyme marker, showed biochemical evidence that IFN is active in both apathogenic and pathogenic infections. On the other hand, spontaneous proliferation in vitro of thymocytes and splenocytes from CVS virus-infected mice was strongly inhibited in contrast to the RV194-2 infection. In the CVS infection, the thymocyte proliferation However, in the RV194-2 infection, the thymocyte proliferation was higher than of the splenocytes. These results suggest a better performance of T-cell response to the RV194-2 infection. This fact can be critical for an enhancement of antibody production in the apathogenic infection and subsequent virus clearance from the brain of RV194-2 virus-infected mice. (author) 1 fig., 3 tabs., 32 refs.

Characterization and clonality of prelymphoma cells of B10 mice treated with fractionated X-irradiation (FX)

International Nuclear Information System (INIS)

Muto, M.; Kubo, E.; Sado, T.; Shimizu, T.; Yamagishi, H.

1992-01-01

With a combined use of cell separation by cell sorter and intrathymic injection assay, it was shown that prelymphoma cells existed in the subpopulation of thymocytes expressing TL-2 antigen which is not expressed on normal thymocytes of B10. Thy 1.2 or B10. Thy 1.1 mice. We then addressed a question whether all TL-2 + cells undergo neoplastic initiation or pre-neoplastic cells develop infrequently from TL-2 + cells. To investigate this problem and to examine the clonality of prelymphoma cells, thymocytes from individual B10. Thy 1.1 mice at various times after FX were stained with anti TL-2 mAb and the content of TL-2 + cells was evaluated. A graded amount of TL-2 + thymocytes from individual mice was injected into the thymuses of B10. Thy 1.2 mice. Although various numbers of TL-2 + cells appeared in the thymus of individual mice 14 - 28 days after FX, the donor type T cell lymphomas developed when 10 2 - 10 5 of TL-2 + cells from 7 individuals out of 20 mice were injected into the recipient mice. On the other hand, injection of TL-2 + cells from other mice (13 out of 20) did not develop donor type T cell lymphoma in spite of TL-2 + cells appearing in the thymus. These results indicate that all TL-2 + cells did not always undergo neoplastic initiation, and prelymphoma cells might develop infrequently from TL-2 + cells. To evaluate the clonality of prelymphoma cells, high molecular weight DNAs were isolated from the donor-derived T cell lymphomas and the rearrangement of T cell receptors examined by Southern blot analysis. The nucleotide sequences of V-J junctions were also determined by polymerase chain reaction techniques. The results indicated that after irradiation neoplastic initiation might occur oligoclonally in some of the TL-2 + cells. (author)

Phenotypic characterization of thymic prelymphoma cells of B10 mice treated with split-dose irradiation

International Nuclear Information System (INIS)

Muto, M.; Kubo, E.; Kamisaku, H.; Sado, T.

1990-01-01

Using an intrathymic injection assay on B10 Thy-1 congenic mice, it was demonstrated that thymic prelymphoma cells first developed within the thymuses from 4 to 8 days after split-dose irradiation and were detected in more than 63% of the test donor thymuses when examined at 21 and 31 days after irradiation. Moreover, some mice (25%) at 2 mo after split-dose irradiation had already developed thymic lymphomas in their thymuses. To characterize these thymic prelymphoma cells, the thymocytes from B10 Thy-1.1 mice 1 mo after irradiation were stained with anti-CD4 and anti-CD8 mAb and were sorted into four subpopulations. These fractionated cells were injected into the recipient thymuses to examine which subpopulation contained thymic prelymphoma cells. The results indicated that thymic prelymphoma cells existed mainly in CD4- CD8- and CD4- CD8+ thymocyte subpopulations and also in CD4+ CD8+ subpopulation. T cell lymphomas derived from CD4- CD8- prelymphoma cells had mainly CD4- CD8- or CD4- CD8+ phenotypes. T cell lymphomas developed from CD4- CD8+ prelymphoma cells mainly expressed CD4- CD8+ or CD4+ CD8+ phenotype. T cell lymphomas originating from CD4+ CD8+ prelymphoma cells were mainly CD4+ CD8+ but some CD4- CD8+ or CD4+ CD8- cells were also present. These thymic prelymphoma cells were further characterized phenotypically in relation to their expression of the marker defined by the mAb against J11d marker and TL-2 (thymus-leukemia) Ag, which is not expressed on normal thymocytes of B10.Thy-1.2 or B10.Thy-1.1 strain, but appears on the thymocytes of lymphomagenic irradiated mice. The results indicated that the prelymphoma cells existed in J11d+, TL-2+ cells

Transcendental Political Systems and the Gravity Model

Science.gov (United States)

Lock, Connor

2012-01-01

This summer I have been working on an Army Deep Futures Model project named Themis. Themis is a JPL based modeling framework that anticipates possible future states for the world within the next 25 years. The goal of this framework is to determine the likelihood that the US Army will need to intervene on behalf of the US strategic interests. Key elements that are modeled within this tool include the world structure and major decisions that are made by key actors. Each actor makes decisions based on their goals and within the constraints of the structure of the system in which they are located. In my research I have focused primarily on the effects of structures upon the decision-making processes of the actors within them. This research is a natural extension of my major program at Georgetown University, where I am studying the International Political Economy and the structures that make it up. My basic goal for this summer project was to be a helpful asset to the Themis modeling team, with any research done or processes learned constituting a bonus.

Characterization of onion lectin (Allium cepa agglutinin) as an immunomodulatory protein inducing Th1-type immune response in vitro.

Science.gov (United States)

Prasanna, Vaddi K; Venkatesh, Yeldur P

2015-06-01

Onion (Allium cepa), a bulb crop of economic importance, is known to have many health benefits. The major objective of the present study is to address the immunomodulatory properties of onion lectin (A. cepa agglutinin; ACA). ACA was purified from onion extract by D-mannose-agarose chromatography (yield: ~1 mg/kg). ACA is non-glycosylated and showed a molecular mass of ~12 kDa under reducing/non-reducing SDS-PAGE; glutaraldehyde cross-linking indicated that ACA is a non-covalent tetramer of ~12 kDa subunits. Its N-terminal sequence (RNVLLNNEGL; UniProt KB Accn. C0HJM8) showed 70-90% homology to mannose-specific Allium agglutinins. ACA showed specific hemagglutination activity of 8200 units/mg and is stable in the pH range 6-10 and up to 45° C. The immunomodulatory activity of ACA was assessed using the macrophage cell line, RAW264.7 and rat peritoneal macrophages; at 0.1 μg/well, it showed a significant increase (6-8-fold vs. control) in the production of nitric oxide at 24h, and significantly stimulated (2-4-fold vs. control) the production of pro-inflammatory cytokines (TNF-α and IL-12) at 24h. ACA (0.1 μg/well) enhanced the proliferation of murine thymocytes by ~4 fold (vs. control) at 24h; however, ACA does not proliferate B cell-enriched rat splenocytes. Further, it significantly elevated the expression levels of cytokines (IFN-γ and IL-2) over the control in murine thymocytes. Taken together, purified ACA induces a Th1-type immune response in vitro. Though present in low amounts, ACA may contribute to the immune-boosting potential of the popular spice onion since considerable amounts are consumed on a daily basis universally. Copyright © 2015 Elsevier B.V. All rights reserved.

Radio-iodinated surface proteins of electrophoretically separated rat lymphocytes

International Nuclear Information System (INIS)

Jilg, W.; Hannig, K.; Zeiller, K.

1980-01-01

Rat thymocytes and lymph node cells were separated into three T and one B subpopulation by means of free flow electrophoresis. The surface proteins of the separated cells were labelled by lactoperoxidase catalysed radioiodination. Most of the label was demonstrated to be at the cell surface. Although the surface protein patterns of the four lamphocyte subpopulations were rather similar, distinctive differences could be found. B cells had six labelled proteins which seemed to be absent in the other cells. In the T cell group three protein bands were identified, each with specificity for peripheral T cells, thymocytes and all T cells respectively. Four other proteins were found which showed quantitative differences between the four cell groups. (orig.) [de

Intrathymic selection of NK1.1+α/β T cell antigen receptor (TCR)+ cells in transgenic mice bearing TCR specific for chicken ovalbumin and restricted to I-Ad

OpenAIRE

Iwabuchi, Chikako; Iwabuchi, Kazuya; Nakagawa, Ken-ichi; Takayanagi, Toshiaki; Nishihori, Hiroki; Tone, Saori; Ogasawara, Kazumasa; Good, Robert A.; Onoé, Kazunori

1998-01-01

Generation and negative selection of NK1.1+α/β T cell receptor (TCR)+ thymocytes were analyzed using TCR-transgenic (B10.D2 × DO10)F1 and (C57BL/6 × DO10)F1 mice and Rag-1−/−/DO10 mice, which had been established by breeding and backcrossing between Rag-1−/− and DO10 mice. Almost all T cells from these mice were shown to bear Vα13/Vβ8.2 that is specific for chicken ovalbumin (cOVA) and restricted to I-Ad. A normal proportion of the NK1.1+ Vα13/Vβ8.2+ thymocytes was generated in these mice. Ho...

Butterfly Ejecta

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 4 September 2003In the heavily cratered southern highlands of Mars, the type of crater seen in this THEMIS visible image is relatively rare. Elliptical craters with 'butterfly' ejecta patterns make up roughly 5% of the total crater population of Mars. They are caused by impactors which hit the surface at oblique, or very shallow angles. Similar craters are also seen in about the same abundance on the Moon and Venus.Image information: VIS instrument. Latitude -24.6, Longitude 41 East (319 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Hydrological evolution of Atlantis basin, Sirenum Terrae, Mars. Preliminar analysis of MOC and THEMIS images.

Science.gov (United States)

de Pablo, M. A.; Márquez, A.; Centeno, J. D.

The Atlantis basin is one of the martian highlands areas where there was proposed the existence of an ancient lake during the early geological history of Mars [1] [2] [3] [4]. The existence of some morphological features inside the basin and in the surrounding area, allow to check the existence of liquid water in the past of the planet. On the other hand, other morphological features indicate the existence of snow and liquid groundwater in recent times. The detailed study of the geomorphologic features allows to make an approach to the hydrological evolution of the Atlantis basin. The study of the geomorphology of this region has been carried out by means of the analysis of MOC high resolution images obtained by the Mars Global Surveyor mission and the THEMIS images, in the visible spectrum, sent by Mars Odyssey spacecrafts. The most clearly morphological feature indicative of the existence of water in the surface of Mars in the past are the numerous channels that end into Atlantis basin from the highest terrains. In addiction to these fluvial channels, the existence of mass flow deposits is also indicative of the existence of water in the area. Some of these slumps are in the internal slopes of impact craters, but others cover huge extensions around the chaotic terrains of the studied area. The lobated ejecta deposits observed in the Atlantis basin region are indicative of the existence of groundwater (solid or liquid) [5]. Serrated reliefs and tables in the borders of the basins are indicative of the existence of a water sheet. Beneath this water sheet some deposits was formed which was eroded, due to the gradual desiccation of the basin, forming the tables and serrated reliefs. The existence of different chaotic terrains in the area implies the existence of huge amounts of water under the surface according to the different models of chaotic terrain formation [6] [7]. The existence of groundwater could be decided by the existence of collapses in the near to the

Effects of recombinant human granulocyte colony-stimulating factor on central and peripheral T lymphocyte reconstitution after sublethal irradiation in mice

International Nuclear Information System (INIS)

Zhao Hongxia; Guo Mei; Sun Xuedong; Ai Huisheng; Sun Wanjun; Hu Hailan; Wei Li

2013-01-01

Granulocyte colony-stimulating factor (G-CSF) is one of the most critical cytokines used for the treatment of acute radiation syndrome (ARS). In addition to the hematopoietic effects of G-CSF on the differentiation and proliferation of myeloid progenitor cells, G-CSF is also known to have immunomodulatory effects. The aim of the present study was to investigate whether G-CSF could accelerate central and peripheral T lymphocyte recovery after a sublethal dose of irradiation. Female BALB/c mice were subjected to 6 Gy of total body irradiation and then were treated with either 100 μg/kg G-CSF or an equal volume of PBS once daily for 14 days. Percentages of thymocyte subpopulations including CD4- CD8-, CD4+ CD8+, CD4+ CD8- and CD4- CD8+ T cells, peripheral CD3+, CD4+ and CD8+ cells were analyzed by flow cytometry. Recent thymic emigrants (RTEs) were assessed by real-time polymerase chain reaction (PCR) using primers specific to the 257-bp T cell receptor rearrangement excision circles (sjTRECs). The proliferative capacity of splenic mononuclear cells upon exposure to ConA was measured by using the Cell Count Kit-8 (CCK-8). G-CSF treatment promoted thymocyte regeneration, accelerated the recovery of CD4+ CD8+ cells and increased the frequency of thymocyte sjTRECs. These effects were more prominent at early time points (Day 28) after irradiation. G-CSF also increased the rate of recovery of peripheral CD3+, CD4+ and CD8+ cells and shortened the period of severe lymphopenia following irradiation. G-CSF also increased the splenic mononuclear cell mitotic responsiveness to ConA more than control-treated cells. Our results show that G-CSF accelerates T cell recovery through both thymic-dependent and thymic-independent pathways, which could be used to increase the rate of immune reconstitution after sublethal irradiation. (author)

Solar arch filaments observed with THEMIS

Czech Academy of Sciences Publication Activity Database

Mein, P.; Briand, C.; Heinzel, Petr; Mein, N.

2000-01-01

Roč. 355, č. 3 (2000), s. 1146-1151 ISSN 0004-6361 R&D Projects: GA AV ČR KSK1003601 Institutional research plan: CEZ:AV0Z1003909 Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.790, year: 2000

Cutting Craters

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 12 November 2003The rims of two old and degraded impact craters are intersected by a graben in this THEMIS image taken near Mangala Fossa. Yardangs and low-albedo wind streaks are observed at the top of the image as well as interesting small grooves on the crater floor. The origin of these enigmatic grooves may be the result of mud or lava and volatile interactions. Variable surface textures observed in the bottom crater floor are the result of different aged lava flows.Image information: VIS instrument. Latitude -15.2, Longitude 219.2 East (140.8 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Textures in Utopia Planitia

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] Bizarre textures cover the surface of eastern Utopia Planitia where there is a high probability that ground ice has played a role in the formation of this unusual landscape.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Ulysses Fossae in Tharsis

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] Extensional forces in the volcanic province of Tharsis have produced a fractured terrain that resembles wrinkled skin.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Hydaspis Chaos

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] Collapsed terrain in Hydapsis Chaos.This is the source terrain for several outflow channels. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.VIS Instrument. Latitude 3.2, Longitude 333.2 East. 19 meter/pixel resolution.

Relative Timing of Substorm-Associated Processes in the Near-Earth Magnetotail and Development of Auroral Onset Arc

Science.gov (United States)

Miyashita, Y.; Ieda, A.; Machida, S.; Hiraki, Y.; Angelopoulos, V.; McFadden, J. P.; Auster, H. U.; Mende, S. B.; Donovan, E.; Larson, D. E.

2014-12-01

We have studied the relative timing of the processes in the near-Earth magnetotail and development of auroral onset arc at the beginning of the expansion phase, based on substorm events observed by the THEMIS spacecraft and ground-based all-sky imagers. The THEMIS all-sky imagers can observe auroras over a wide area with temporal and spacial resolutions higher than spacecraft-borne cameras. This enables us to investigate the timing of auroral development in more detail than before. A few min after the appearance and intensification of an auroral onset arc, it begins to form wave-like structure. Then auroral poleward expansion begins another few min later. THEMIS magnetotail observations clearly show that magnetic reconnection is initiated at X~-20 Re at least 1-2 min before the intensification of auroral onset arc. Then low-frequency waves are excited in the plasma sheet at X~-10 Re 2 min before dipolarization, which is simultaneous with the formation of auroral wave-like structure. Dipolarization begins at the same time as the auroral poleward expansion. These results suggest that near-Earth magnetic reconnection plays some role in the development of dipolarization and auroral onset arc.

Immunoprotective activity and antioxidant properties of cactus (Opuntia ficus indica) extract against chlorpyrifos toxicity in rats.

Science.gov (United States)

Smida, Amani; Ncibi, Saida; Taleb, Jihen; Ben Saad, Anouar; Ncib, Sana; Zourgui, Lazhar

2017-04-01

Opuntia ficus indica (family Cactaceae) is a typical Mediterranean plant, mainly used in food and traditional folk medicine. The present study was designed to evaluate the protective effect of Opuntia ficus indica extract against chlorpyrifos (CPF)-induced immunotoxicity in rats. The experimental animals consisted of four groups of Wistar rats (5-6 weeks old) of eight each: a control group, a group treated with CPF (10mg/kg), a group treated with Opuntia ficus indica extract (100mg/kg), and a group treated with cactus extract then treated with CPF. These components were daily administered by gavage for 30days. After treatment, immunotoxicity was estimated by a count of thymocytes, splenocytes, stem cells in the bone marrow, relative weights of thymus and spleen, DNA aspects, and oxidative stress status in these organs. Results showed that CPF could induce thymus atrophy, splenomegaly, and a decrease in the cell number in the bone marrow. It also increased the oxidative stress markers resulting in elevated levels of the lipid peroxidation with a concomitant decrease in the levels of enzymatic antioxidants (SOD, CAT, GPx) in both spleen and thymus, and also degradation of thymocyte and splenocyte DNA. Consistent histological changes were found in the spleen and thymus under CPF treatment. However, administration of Opuntia ficus indica extract was found to alleviate this CPF-induced damage. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Fate of thymic radioactivity after local labeling with 125Iododeoxyuridine

International Nuclear Information System (INIS)

Laissue, J.A.; Chanana, A.D.; Cottier, H.; Cronkite, E.P.; Joel, D.D.

1976-01-01

The thymic cortex was locally labeled with 125 Iododeoxyuridine ( 125 IUdR) in young adult mice in an attempt to provide a simple quantitative assessment of the fate of cortical thymocytes. Similarly operated and nonoperated mice given 125 IUdR intravenously were used for comparison. Analogous experiments were performed in adrenalectomized animals. More than 90 percent of thymic activity present 1 day after labeling had been lost by day 8. That proportion of radioactivity contributed to a given organ by accumulation of labeled thymic migrants was estimated by comparison of values obtained after local labeling with those acquired after systemic labeling. Thymic cell accumulation was apparent in the intestine, spleen, mesenteric lymph node, and femurs of locally labeled mice; however, only a few percent of the total activity lost from the thymus was accounted for in these lymphoid organs. The pattern of fecal and urinary elimination of 125 I did not markedly differ in the various experimental groups, the bulk of the activity being recovered in the urine. The intestine could not be ruled out as a major site of thymocyte loss. Since significant radiation or pharmacologic toxicity was unlikely with the doses of 125 IUdR used, the data indicated that the vast majority of newly formed thymocytes dies after a short life and only a small fraction of thymic migrants is longer lived

Whole Body Hyperthermia in Mice Confers Delayed Radioprotection at Cellular and Tissue Levels: Inducible Heat Shock Proteins as Endogenous Radioprotectors

International Nuclear Information System (INIS)

Malytina, Y. V.; Sements, T. N.; Semina, O. V.; Mosin, A. F.; Kabakov, A.

2004-01-01

It was previously shown on heat shock protein (Hsp)-over expressing cell lines that the increased intracellular content of Hsp 70 or Hsp27 is associated with the elevated radioresistance. However, it was so far unknown whether the in vivo Fsp induction by stressful preconditioning can confer radioprotection at the tissue and cellular levels. In the present study, we examined how the in vivo up-regulation of the Hsp expression in response to mild whole body hyperthermia (42 degrees C, 10 min) in mice changes susceptibility of their bone marrow stem cells and thymocytes to subsequent gamma-irradiation. to assess the expectable contribution of stress-inducible Hsp we used injections with Quercetin, a flavonoid inhibiting the stress-responsive Hsp induction. The results demonstrate that the bone marrow stem cells and thymocytes from heat-preconditioned mice were more radioresistant than those from the non-preconditioned animals. the radioprotection was well manifested if mice or their isolated thymocytes were irradiated 18-25 h after the in vivo hyperthermia. This delayed radioprotection resulting from the heat preconditioning was suppressed in Quercetin-injected mice. The revealed correlation between the intracellular Hsp accumulation and the acquired Quercetin-sensitive radioprotection suggests a beneficial role of Hsps as of endogenous radioprotectors. Our finding discovers new ways for artificial modulation of effects of irradiation on target cells via manipulating the Hsp expression. (Author) 17 refs

Ephrinb1 and Ephrinb2 Are Associated with Interleukin-7 Receptor α and Retard Its Internalization from the Cell Surface*

Science.gov (United States)

Luo, Hongyu; Wu, Zenghui; Qi, Shijie; Jin, Wei; Han, Bing; Wu, Jiangping

2011-01-01

IL-7 plays vital roles in thymocyte development, T cell homeostasis, and the survival of these cells. IL-7 receptor α (IL-7Rα) on thymocytes and T cells is rapidly internalized upon IL-7 ligation. Ephrins (Efns) are cell surface molecules and ligands of the largest receptor kinase family, Eph kinases. We discovered that T cell-specific double gene knock-out (dKO) of Efnb1 and Efnb2 in mice led to reduced IL-7Rα expression in thymocytes and T cells, and that IL-7Rα down-regulation was accelerated in dKO CD4 cells upon IL-7 treatment. On the other hand, Efnb1 and Efnb2 overexpression on T cell lymphoma EL4 cells retarded IL-7Rα down-regulation. dKO T cells manifested compromised STAT5 activation and homeostatic proliferation, an IL-7-dependent process. Fluorescence resonance energy transfer and immunoprecipitation demonstrated that Efnb1 and Efnb2 interacted physically with IL-7Rα. Such interaction likely retarded IL-7Rα internalization, as Efnb1 and Efnb2 were not internalized. Therefore, we revealed a novel function of Efnb1 and Efnb2 in stabilizing IL-7Rα expression at the post-translational level, and a previously unknown modus operandi of Efnbs in the regulation of expression of other vital cell surface receptors. PMID:22069310

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

International Nuclear Information System (INIS)

Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D.

2015-01-01

Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch ICN-TG ). Following exposure of adult Notch ICN-TG mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch ICN-TG offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch ICN-TG offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch-induced thymoma was different in

Studies on radiation-induced thymic lymphomagenesis in B10 strain mice

International Nuclear Information System (INIS)

Muto, Masahiro

1989-01-01

Using B10.Thy 1 congenic strain mice, we reexamined the earlier results by Kaplan and others that lymphomas could develop from lymphocytes present in the nonirradiated parental thymuses grafted into thymectomized, fractionally irradiated H-2 semiincompatible recipient mice. The results indicated that 37 out of 91 thymectomized and irradiated B10.Thy 1.2 mice developed lymphomas of which 75 % were shown to have originated from grafted thymuses. The evidence was not obtained that supported the involvement of endogenous MuLV or some kind of transmissible agents during thymic lymphomagenesis. We found, with intrathymic injection assay, that 'preneoplastic' cells that will eventually develop into thymic lymphomas under the influence of thymic microenvironment first appeared in the thymuses about 4-8 days after irradiation. These thymic prelymphoma cells 'thymus-dependent' preneoplastic cells were detected in 26.1 % of the test donor thymuses when examined at 14 days and in more than 63 % 21 and 31 days after irradiation. It was found that lymphomagenic irradiation resulted in the anomalous appearance of CD4 + and/or CD8 + thymocytes bearing IL-2 receptor (IL-2R) which were different from normal thymocyte subpopulations. Thymic prelymphoma cells existed mainly in CD4 - CD8 - and CD4 - CD8 + thymocyted subpopulations and also in CD4 + CD8 + subpopulation. T cell lymphomas derived from CD4 - CD8 - prelymphoma cells had mainly CD4 - CD8 - or CD4 - CD8 + phenotypes. T cell lymphomas developed from CD4 - CD8 + prelymphoma cells mainly expressed CD4 - CD8 + or CD4 + CD8 + phenotype. T cell lymphomas originated from CD4 + CD8 + prelymphoma cells were mainly CD4 + CD8 + but some CD4 - CD8 + or CD4 + CD8 - cells were also present. These T cell lymphomas expressed IL-2R on various levels. The development of thymic prelymphoma cells is discussed in view of thymocyte differentiation. (J.P.N)

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

Energy Technology Data Exchange (ETDEWEB)

Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D., E-mail: laiosa@uwm.edu

2015-03-01

Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch

Identification of differentially expressed proteins in spontaneous thymic lymphomas from knockout mice with deletion of p53

DEFF Research Database (Denmark)

Honoré, Bent; Buus, Søren; Claësson, Mogens H

2008-01-01

ABSTRACT: BACKGROUND: Knockout mice with a deletion of p53 spontaneously develop thymic lymphomas. Two cell lines (SM5 and SM7), established from two independent tumours, exhibited about fifty to seventy two-fold differentially expressed proteins compared to wild type thymocytes by two-dimensiona......ABSTRACT: BACKGROUND: Knockout mice with a deletion of p53 spontaneously develop thymic lymphomas. Two cell lines (SM5 and SM7), established from two independent tumours, exhibited about fifty to seventy two-fold differentially expressed proteins compared to wild type thymocytes by two...... alpha type 3, transforming acidic coiled-coil containing protein 3, mitochondrial ornithine aminotransferase and epidermal fatty acid binding protein and down-regulation of adenylosuccinate synthetase, tubulin beta-3 chain, a 25 kDa actin fragment, proteasome subunit beta type 9, cofilin-1 and glia...

Processes of Geology

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 16 July 2003This THEMIS visible image captures a complex process of deposition, burial and exhumation. The crater ejecta in the top of the image is in the form of flow lobes, indicating that the crater was formed in volatile-rich terrain. While a radial pattern can be seen in the ejecta, the pattern is sharper in the lower half of the ejecta. This is because the top half of the ejecta is still buried by a thin layer of sediment. It is most likely that at one time the entire area was covered. Wind, and perhaps water erosion have started to remove this layer, once again exposing the what was present underneath.Image information: VIS instrument. Latitude -34.3, Longitude 181.2 East (178.8 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Ares Vallis Polygons

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] This jumble of eroded ridges and mesas occurs within Ares Vallis, one of the largest catastrophic outflow channels on the planet. Floods raged through this channel, portions of which are up to 25 km wide, pouring out into the Chryse Basin to the north. Close inspection of the THEMIS image reveals polygonal shapes on the floor of the channel system. Polygonal terrain on Mars is fairly common although the variety of forms and scales of the polygons suggests multiple modes of origin. Those in Ares Vallis resemble giant desiccation polygons that form in soils on Earth when a moist layer at depth drys out. While polygons can form in icy soils (permafrost) and even lava flows, their presence in a channel thought to have been carved by flowing water is at least consistent with a mode of origin that involved liquid water.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Suppression of multiple bioactivities of interleukin-1 and interleukin-2 production by U937 conditioned medium

International Nuclear Information System (INIS)

Wiblin, R.T.; Edmonds, K.; Ellner, J.J.

1986-01-01

The human macrophage-like cell line U937 spontaneously produces a factor which blocks interleukin-1 (IL-1) activity for mouse thymocytes but not mitosis of T-lymphoblastoid cells. The authors examined the effects of U937 conditioned medium (CM) on other IL-1 activities and on interleukin-2 (IL-2) production. U937 was cultured at 5 x 10 6 /ml in RPMI-1640 at 37 0 C for 5 days. The resulting CM inhibited the mitogenic response of C3H/HeJ mouse thymocytes to an IL-1 standard, with an inhibitory of activity of 6.64 U/ml (1 U = reciprocal dilution producing 50% inhibition of maximal response). Similarly, CM inhibited (10.12 U/ml) the fibroblast stimulation promoter activity of IL-1. The effect of CM on IL-2 production was assessed in a direct assay in which IL-2 production by γ-irradiated (12,000 rads) MLA-144 lymphosarcoma cells was assayed as 3 H-thymidine incorporation in CTLL-20 cells. The suppressive activity of CM was 4.95 U/ml; CM did not interfere with the response of CTLL-20 to IL-2. These studies establish that U937 produces factors with multiple, related biological activities; U937 CM blocks IL-2 dependent (thymocyte mitogenesis) and IL-2 independent (fibroblast proliferation) IL-1 activities and interferes with production of, but not response to, IL-2. U937 is an excellent model to study growth inhibitory properties of mononuclear phagocytes

Immunoregulatory effect of evodiamine in mice of various germlines.

Science.gov (United States)

Hu, Hai-Yan; Song, Zhao-Yang; Deng, Lan; Zhang, Mei-Xia

2008-08-01

The aim of this study was to investigate the effect of evodiamine on the proliferation and the immune function of thymocytes and splenocyte of mice from three germlines, which were 8 weeks old masculinity BALB/c, C57BL/6 and F1 hybridization mice. Cells of thymus and spleen were harvested and prepared as unicellular suspension. Cell proliferation was detected by MTT method, while the concentration of IL-2 was detected by ELISA, mRNA levels of bcl-2 and cdk2 in cells treated with evodiamine were detected by RT-PCR, the apoptosis rate and intracellular reactive oxygen species (ROS) concentration were analyzed by FCM, and the protein levels of BCL-2, CDK2 and BAX were determined by fluorescence microscope. The results indicated that at 0.5, 0.75 and 1 micromol/L, evodiamine inhibited the proliferation and externalization of thymocytes and splenocytes stimulated with ConA (p rate increased at a prolong period of time. After treatment with evodiamine for 24 and 48 hours, the cells were divided into two groups, one of which was negatively stained by 2 7-dichlorofluorescein (DCF), which indicated that ROS level decreased significantly in the dying cells. It is concluded that evodiamine inhibits proliferation and induces apoptosis of thymocytes and splenocytes from different germline mice, and at the same time decreases secretion of IL-2 through down-regulating bcl-2 and cdk2 levels.

Thy-1+ dendritic cells in murine epidermis are bone marrow-derived

International Nuclear Information System (INIS)

Breathnach, S.M.; Katz, S.I.

1984-01-01

Thy-1+, Ly-5+ dendritic cells have recently been described as a resident cell population in murine epidermis, but their ontogeny and function are unknown. The origin and turnover of epidermal Thy-1+ cells utilizing chimeric mice were investigated. Lethally x-irradiated AKR/J (Thy-1.1+) and AKR/Cum (Thy-1.2+) mice were reconstituted with allogeneic bone marrow cells with or without thymocytes from congenic AKR/Cum or AKR/J mice, respectively. The density of residual indigenous Thy-1.1+ cells in AKR/J chimeras and Thy-1.2+ cells in AKR/Cum chimeras was substantially reduced following x-irradiation, as determined by immunofluorescence staining of epidermal sheets. Epidermal repopulation by allogeneic Thy-1+ dendritic epidermal cells was first observed at 5 weeks in AKR/J chimeras and at 7 weeks in AKR/Cum chimeras and progressed slowly. Repopulation was not enhanced by increasing the number of allogeneic bone marrow cells injected from 2 X 10(7) to 10(8) cells or by the addition of 8 X 10(7) allogeneic thymocytes to the donor inoculate. Epidermal repopulation by allogeneic Thy-1.2+ cells was not seen in AKR/J mice reconstituted with syngeneic bone marrow cells and allogeneic Thy-1.2+ AKR/Cum thymocytes. Taken together, these results indicate that Thy-1+ dendritic epidermal cells are derived from the bone marrow and suggest that they are not related to conventional peripheral T-lymphocytes

Study on proliferative responses to host Ia antigens in allogeneic bone marrow chimera in mice: sequential analysis of the reactivity and characterization of the cells involved in the responses

International Nuclear Information System (INIS)

Iwabuchi, K.; Ogasawara, K.; Ogasawara, M.; Yasumizu, R.; Noguchi, M.; Geng, L.; Fujita, M.; Good, R.A.; Onoe, K.

1987-01-01

Irradiation bone marrow chimeras were established by reconstitution of lethally irradiated AKR mice with C57BL/10 marrow cells to permit serial analysis of the developing reactivities of lymphocytes from such chimeras, [B10----AKR], against donor, host, or third party antigens. We found that substantial proliferative responses to Ia antigens of the recipient strain and also to third party antigens were generated by the thymocytes obtained from the irradiation chimeras at an early stage after bone marrow reconstitution. The majority of the responding thymocytes had surfaces lacking demonstrable peanut agglutinin receptors and were donor type Thy-1+, Ly-2-, and L3T4+ in both anti-recipient and anti-third party MLR. In anti-host responses, however, Ly-2+ thymocytes seemed to be at least partially involved. This capacity of thymus cells to mount a response to antigens of the recipient strain declined shortly thereafter, whereas the capacity to mount MLR against third party antigens persisted. The spleen cells of [B10----AKR] chimeras at the same time developed a more durable capability to exhibit anti-host reactivities and a permanent capability of reacting to third party allo-antigens. The stimulator antigens were Ia molecules on the stimulator cells in both anti-recipient and anti-third party MLR. The responding splenocytes were of donor origin and most of them had Thy-1+, Ly-1+2-, and L3T4+ phenotype

Activation of Extracellular Signal-Regulated Kinase but Not of p38 Mitogen-Activated Protein Kinase Pathways in Lymphocytes Requires Allosteric Activation of SOS

Science.gov (United States)

Jun, Jesse E.; Yang, Ming; Chen, Hang; Chakraborty, Arup K.

2013-01-01

Thymocytes convert graded T cell receptor (TCR) signals into positive selection or deletion, and activation of extracellular signal-related kinase (ERK), p38, and Jun N-terminal protein kinase (JNK) mitogen-activated protein kinases (MAPKs) has been postulated to play a discriminatory role. Two families of Ras guanine nucleotide exchange factors (RasGEFs), SOS and RasGRP, activate Ras and the downstream RAF-MEK-ERK pathway. The pathways leading to lymphocyte p38 and JNK activation are less well defined. We previously described how RasGRP alone induces analog Ras-ERK activation while SOS and RasGRP cooperate to establish bimodal ERK activation. Here we employed computational modeling and biochemical experiments with model cell lines and thymocytes to show that TCR-induced ERK activation grows exponentially in thymocytes and that a W729E allosteric pocket mutant, SOS1, can only reconstitute analog ERK signaling. In agreement with RasGRP allosterically priming SOS, exponential ERK activation is severely decreased by pharmacological or genetic perturbation of the phospholipase Cγ (PLCγ)-diacylglycerol-RasGRP1 pathway. In contrast, p38 activation is not sharply thresholded and requires high-level TCR signal input. Rac and p38 activation depends on SOS1 expression but not allosteric activation. Based on computational predictions and experiments exploring whether SOS functions as a RacGEF or adaptor in Rac-p38 activation, we established that the presence of SOS1, but not its enzymatic activity, is critical for p38 activation. PMID:23589333

The influence of combined treatment of Cd, and γ-irradiation on DNA damage and repair in lymphoid tissues of mice

International Nuclear Information System (INIS)

Privezentsev, K.V.; Sirota, N.P.; Gaziev, A.I.

1996-01-01

The effect of combined treatment of Cd and γ-irradiation on DNA damage and repair was studied in lymphoid tissues of mice using single-cell gel assay. Single i.p. injection of CdCl 2 (1 mg Cd/kg body wt), 2 h prior to irradiation resulted in increasing of DNA lesions in peripheral blood lymphocytes (PBL) when compared to non-injected animals. However, the same treatment, 48 h prior to irradiation is shown to decrease DNA damage in PBL and splenocytes in comparison with untreated mice. In thymocytes maximal protective effect of Cd was determined when mice were irradiated in 24 h after injection. The protective effect observed is due to decreasing of initial level of DNA damage in thymocytes as well as acceleration of DNA repair in PBL and splenocytes. 28 refs.; 2 figs

The interleukin-15 system suppresses T cell-mediated autoimmunity by regulating negative selection and nT(H)17 cell homeostasis in the thymus.

Science.gov (United States)

Hou, Mau-Sheng; Huang, Shih-Ting; Tsai, Ming-Han; Yen, Ching-Cheng; Lai, Yein-Gei; Liou, Yae-Huei; Lin, Chih-Kung; Liao, Nan-Shih

2015-01-01

The interleukin-15 (IL-15) system is important for regulating both innate and adaptive immune responses, however, its role in autoimmune disease remained unclear. Here we found that Il15(-/-) and Il15ra(-/-) mice spontaneously developed late-onset autoimmune phenotypes. CD4(+) T cells of the knockout mice showed elevated autoreactivity as demonstrated by the induction of lymphocyte infiltration in the lacrimal and salivary glands when transferred into nude mice. The antigen-presenting cells in the thymic medullary regions expressed IL-15 and IL-15Rα, whose deficiency resulted in insufficient negative selection and elevated number of natural IL-17A-producing CD4(+) thymocytes. These findings reveal previously unknown functions of the IL-15 system in thymocyte development, and thus a new layer of regulation in T cell-mediated autoimmunity. Copyright © 2014 Elsevier Ltd. All rights reserved.

77 FR 7628 - Self-Regulatory Organizations; New York Stock Exchange LLC; NYSE Amex LLC; Order Instituting...

Science.gov (United States)

2012-02-13

... October 17, 2011 (``Themis Letter''); Garret Cook, dated November 4, 2011 (``Cook Letter''); James.... Larry Paden, Bright Trading, dated December 1, 2011 (``Paden Letter''); Thomas Dercks, dated December 1...

Effect of a probiotic fermented milk on the thymus in Balb/c mice under non-severe protein-energy malnutrition.

Science.gov (United States)

Núñez, Ivanna Novotny; Galdeano, Carolina Maldonado; Carmuega, Esteban; Weill, Ricardo; de Moreno de LeBlanc, Alejandra; Perdigón, Gabriela

2013-08-28

Protein–energy malnutrition (PEM) causes a significant impairment of the immune system, the thymus being one of the most affected organs. It has been demonstrated that the administration of probiotic fermented milk (PFM) recovered the intestinal barrier, histological alterations and mucosal and systemic immune functions in a non-severe malnutrition model using BALB/c mice. The aim of the present study was to evaluate, in the same model of malnutrition, the effect of a PFM added to a re-nutrition diet on the recovery of the thymus, analysing histological and functional alterations caused by malnutrition. Mice were undernourished and divided into three groups according to the dietary supplement received during re-nutrition: milk, PFM or its bacterial-free supernatant (BFS). They were compared with well-nourished and malnourished mice. PFM was the most effective re-nutrition supplement to improve the histology of the thymus, decreasing cellular apoptosis in this organ and recovering the percentage of CD4þ/CD82 single-positive thymocytes. Immature doublepositive thymocytes were increased in the malnourished control (MC). The production of different cytokines in the thymus was increased in mice given PFM, compared with the mice that received other dietary supplements and MC. Mice given the BFS presented an improvement in the thymus similar to those that received milk. We demonstrated the importance of the whole PFM supplementation on the histological and functional recovery of the thymus in a non-severe PEM model.

Protective effects of egg-milk with MT on mice damaged by irradiation

Energy Technology Data Exchange (ETDEWEB)

Hongguang, Zhao; Zhicheng, Wang; Xiang, Du; Zhe, Lu; Xiaoyan, Jiang; Shouliang, Gong [MH Radiobiology Research Unit, School of Public Health, Jilin Univ., Changchun (China); Jingyu, Shi [Haerbin Chunyuan Biotechnology Development, Co., LTD, Haerbin (China)

2005-07-15

Objective: To investigate the influences of low dose radiation (LDR) on the inhibitory effects of tumorassociated antigen peptide (TAP) extract of H-22 hepatocarcinoma in mice. Methods: Mild acid elution method was applied to prepare TAP extract (MW {<=} 3000) from tumor cell membrane. The mice were given by whole-body irradiation (WBI) with 75 mGy X-rays 12 h before immunization with TAP extract. After immunization, the cell cycle progression of the thymocytes was detected with flow cytometry, the response of the splenocytes to Con A and the percentage of T cell subsets in splenocytes were analyzed. Meantime, the tumor-inhibited effect was observed in vive. Results: The present experiment showed that the TAP extract reduced the incidence of the transplanted tumor, delayed the average appearing time and decreased the growth speed of the tumor. The response of the splenocytes to Con A increased significantly as compared with that in the control group after mice were immunized with TAP extract, but there were no changes in the cell cycle progression of thymocytes. WBI with 75 mGy X-rays given to the mice 12 h before immunization could enhance the inhibitory effects of TAP extract, the percentage of S phase increased significantly as compared with that in the TAP extract group, and the percentage of the CD8{sup +} splenocytes increased. Conclusion: The results suggest that LDR can efficiently activate the function of immune system, and enhanced the inhibitory effects of the TAP extract. (authors)

ANTI·RED CELL ACTIVITY OF LYMPHOCYTOTOXIC ANTIBODIES ...

African Journals Online (AJOL)

1971-05-08

May 8, 1971 ... it can be concluded that the Iymphocytes also share anti- gens with thymocytes .... antibodies, yet seem to lack the power to prolong graft survival, indicates ..... This limitation affects our knowledge of its in vivo activity when ...

Expression of tyrosine kinase gene in mouse thymic stromal cells

NARCIS (Netherlands)

Rinke de Wit, T. F.; Izon, D. J.; Revilla, C.; Oosterwegel, M.; Bakker, A. Q.; van Ewijk, W.; Kruisbeek, A. M.

1996-01-01

Amongst the most important signal transduction molecules involved in regulating growth and differentiation are the protein tyrosine kinases (PTK). Since T cell development is a consequence of interactions between thymic stromal cells (TSC) and thymocytes, identification of the PTK in both

Fluorescence studies on radiation oxidative damage to membranes ...

Indian Academy of Sciences (India)

Unknown

genesis including induction of cancer.4,5 The damaging events at the molecular ... old mice as described earlier.14 Thymocytes (1 × 107 cells/ml) were labelled with DCFH- .... toxicity (eds) M W Miller and A E Shamou (New York: Plenum) p.

Modulatory effects of cAMP and PKC activation on gap junctional intercellular communication among thymic epithelial cells

Directory of Open Access Journals (Sweden)

Neves-dos-Santos Sandra

2010-01-01

Full Text Available Abstract Background We investigated the effects of the signaling molecules, cyclic AMP (cAMP and protein-kinase C (PKC, on gap junctional intercellular communication (GJIC between thymic epithelial cells (TEC. Results Treatment with 8-Br-cAMP, a cAMP analog; or forskolin, which stimulates cAMP production, resulted in an increase in dye transfer between adjacent TEC, inducing a three-fold enhancement in the mean fluorescence of coupled cells, ascertained by flow cytometry after calcein transfer. These treatments also increased Cx43 mRNA expression, and stimulated Cx43 protein accumulation in regions of intercellular contacts. VIP, adenosine, and epinephrine which may also signal through cyclic nucleotides were tested. The first two molecules did not mimic the effects of 8-Br-cAMP, however epinephrine was able to increase GJIC suggesting that this molecule functions as an endogenous inter-TEC GJIC modulators. Stimulation of PKC by phorbol-myristate-acetate inhibited inter-TEC GJIC. Importantly, both the enhancing and the decreasing effects, respectively induced by cAMP and PKC, were observed in both mouse and human TEC preparations. Lastly, experiments using mouse thymocyte/TEC heterocellular co-cultures suggested that the presence of thymocytes does not affect the degree of inter-TEC GJIC. Conclusions Overall, our data indicate that cAMP and PKC intracellular pathways are involved in the homeostatic control of the gap junction-mediated communication in the thymic epithelium, exerting respectively a positive and negative role upon cell coupling. This control is phylogenetically conserved in the thymus, since it was seen in both mouse and human TEC preparations. Lastly, our work provides new clues for a better understanding of how the thymic epithelial network can work as a physiological syncytium.

Identification and cloning of a prethymic precursor T lymphocyte from a population of common acute lymphoblastic leukemia antigen (CALLA)-positive fetal bone marrow cells

DEFF Research Database (Denmark)

Hokland, P; Hokland, M; Daley, J

1987-01-01

We have cloned common acute lymphoblastic leukemia (CALLA)-positive cells from human fetal bone marrow containing less than 1 in 10,000 E-RFC in round-bottomed microtiter wells (one cell per well) using the autocloning unit of an EPICS-V cell sorter. Expansion of such cells (with IL-2 and heavily...... irradiated autologous thymocytes as feeder cells) resulted in growth in 6-14% of the wells (mean, 11%) with cells with mature T lymphocyte phenotype. Two-color fluorescence analysis of outgrowing cultures furthermore ascertained that these cells had differentiated through a phase of simultaneous expression...... of T4 and T8 antigens and at the same time expression of the thymocyte-associated T6 antigens. Thus, given the fact that 10-20% of T cell acute lymphoblastic leukemia (T-ALLs) are CALLA+, we have been able to identify a human prethymic T lymphocyte population that might be the normal counterpart...

Characteristic of immunological adaptive response induced by low level whole body irradiation with X-rays in mice

International Nuclear Information System (INIS)

Ju Guizhi; Song Chunhua; Qi Jin; Liu Shuzheng

1995-01-01

The range of preirradiated doses (D 1 ) and challenge doses (D 2 ) for the induction of immunological adaptive response and the optimum time intervals between D 1 and D 2 were investigated in Kunming mice. The results were as follows: 1. Single whole body preirradiation by X-rays with D 1 doses of 25∼100 mGy (12.5 mGy/min) could induce adaptive response of spontaneous incorporation of 3 H-TdR into thymocytes and the reaction of splenocytes to LPS. 2. With D 2 doses of 1.0 to 1.5 Gy, the adaptive response of spontaneous incorporation of 3 H-TdR into thymocytes and the reaction of splenocytes to ConA and LPS could be induced. 3. The optimum interval for the induction of immunological adaptive response between D 1 and D 2 could be 6∼12 h

Cocoa-enriched diet enhances antioxidant enzyme activity and modulates lymphocyte composition in thymus from young rats.

Science.gov (United States)

Ramiro-Puig, Emma; Urpí-Sardà, Mireia; Pérez-Cano, Francisco J; Franch, Angels; Castellote, Cristina; Andrés-Lacueva, Cristina; Izquierdo-Pulido, Maria; Castell, Margarida

2007-08-08

Cocoa is a rich source of flavonoids, mainly (-)-epicatechin, (+)-catechin, and procyanidins. This article reports the effect of continuous cocoa intake on antioxidant capacity in plasma and tissues, including lymphoid organs and liver, from young rats. Weaned Wistar rats received natural cocoa (4% or 10% food intake) for three weeks, corresponding to their infancy. Flavonoid absorption was confirmed through the quantification of epicatechin metabolites in urine. Total antioxidant capacity (TAC) and the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase, were examined. Cocoa intake enhanced TAC in all tissues especially in thymus. Moreover, thymus SOD and catalase activities were also dose-dependently increased by cocoa. It was also analyzed whether the enhanced antioxidant system in thymus could influence its cellular composition. An increase in the percentage of thymocytes in advanced development stage was found. In summary, cocoa diet enhances thymus antioxidant defenses and influences thymocyte differentiation.

Thymic B cell development is controlled by the B potential of progenitors via both hematopoietic-intrinsic and thymic microenvironment-intrinsic regulatory mechanisms.

Directory of Open Access Journals (Sweden)

Shiyun Xiao

Full Text Available Hematopoietic stem cells (HSCs derived from birth through adult possess differing differentiation potential for T or B cell fate in the thymus; neonatal bone marrow (BM cells also have a higher potential for B cell production in BM compared to adult HSCs. We hypothesized that this hematopoietic-intrinsic B potential might also regulate B cell development in the thymus during ontogeny.Foxn1lacZ mutant mice are a model in which down regulation of a thymic epithelial cell (TEC specific transcription factor beginning one week postnatal causes a dramatic reduction of thymocytes production. In this study, we found that while T cells were decreased, the frequency of thymic B cells was greatly increased in these mutants in the perinatal period. We used this model to characterize the mechanisms in the thymus controlling B cell development.Foxn1lacZ mutants, T cell committed intrathymic progenitors (DN1a,b were progressively reduced beginning one week after birth, while thymic B cells peaked at 3-4 weeks with pre-B-II progenitor phenotype, and originated in the thymus. Heterochronic chimeras showed that the capacity for thymic B cell production was due to a combination of higher B potential of neonatal HSCs, combined with a thymic microenvironment deficiency including reduction of DL4 and increase of IL-7 that promoted B cell fate.Our findings indicate that the capacity and time course for thymic B-cell production are primarily controlled by the hematopoietic-intrinsic potential for B cells themselves during ontogeny, but that signals from TECs microenvironment also influence the frequency and differentiation potential of B cell development in the thymus.

Martian Braille

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Just north of the hematite deposit in Meridiani Planum, the remnants of a formerly extensive layer of material remain as isolated knobs and buttes. Note the transition from north to south in the size and frequency of these features, a reflection of the decreasing elevation along this trend.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude -0, Longitude 353 East (7 West). 19 meter/pixel resolution.

Frost-free Dunes

Science.gov (United States)

2006-01-01

[figure removed for brevity, see original site] Context image for PIA03291 Frost-free Dunes These dark dunes are frost covered for most of the year. As southern summer draws to a close, the dunes have been completely defrosted. Image information: VIS instrument. Latitude -66.6N, Longitude 37.0E. 34 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Iani Chaos

Science.gov (United States)

2005-01-01

[figure removed for brevity, see original site] Context image for PIA03200 Iani Chaos This VIS image of Iani Chaos shows the layered deposit that occurs on the floor. It appears that the layers were deposited after the chaos was formed. Image information: VIS instrument. Latitude 2.3S, Longitude 342.3E. 17 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2-D multiline spectroscopy of the solar photosphere

Science.gov (United States)

Berrilli, F.; Consolini, G.; Pietropaolo, E.; Caccin, B.; Penza, V.; Lepreti, F.

2002-01-01

The structure and dynamics of the photosphere are investigated, with time series of broadband and monochromatic images of quiet granulation, at the solar disk center. Images were acquired with the IPM observing mode at the THEMIS telescope. Velocity and line center intensity fields, derived from the observation of three different photospheric lines, are used to study velocity and intensity patterns at different heights in the photosphere. Automatic segmentation procedures are applied to velocity and intensity frames to extract solar features, and to investigate the dependence of their properties at different scales and heights. We find a dependence of the statistical properties of upflow and downflow regions on the atmospheric height. Larger granules, passing through a great part of the photosphere, are used to investigate the damping of convective motions in stably stratified layers. The results suggest the occurrence of an intense braking in the deep photosphere (first ~ 120 km). Furthermore, we investigate the temporal and spatial evolution of velocity fields, deriving typical time scales of dynamical processes relative to different solar features. In particular, for two selected isolated exploders, we reveal a velocity deceleration in the central region since the early phase of their fragmentation. Based on observations made with THEMIS-CNRS/INSU-CNR operated on the island of Tenerife by THEMIS S.L. in the Spanish Observatorio del Teide of the Instituto de Astrofisica de Canarias.

Examination of Phyllosilicate-bearing Materials in the Vicinity of the Nili Fossae Using Thermal Infrared Data

Science.gov (United States)

McDowell, M. L.; Hamilton, V. E.

2007-07-01

We examine THEMIS and TES TIR data in areas OMEGA identified as containing phyllosilicates to better understand the spectral characteristics of phyllosilicate-bearing materials and reliable TES detection limits for modeled phyllosilicate abundances.

In vitro immunotoxicity of bis(tri-n-butyltin)oxide (TBTO) studied by toxicogenomics

International Nuclear Information System (INIS)

Baken, Kirsten A.; Arkusz, Joanna; Pennings, Jeroen L.A.; Vandebriel, Rob J.; Loveren, Henk van

2007-01-01

The biocide and environmental pollutant bis(tri-n-butyltin)oxide (TBTO) causes thymus atrophy in rodents. Whether the depletion of thymic lymphocytes by tributyltin compounds may be the result of inhibition of cell proliferation or induction of apoptosis is subject of debate. We examined gene expression profiles in primary rat thymocytes exposed to TBTO in vitro at dose levels of 0, 0.1, 0.3, 0.5, and 1.0 μM. By measuring cell viability and apoptosis, exposure conditions were selected that would provide information on changes in gene expression preceding or accompanying functional effects of TBTO. Several processes related to TBTO-induced toxicity were detected at the transcriptome level. Effects on lipid metabolisms appeared to be the first indication of disruption of cellular function. Many transcriptional effects of TBTO at higher dose levels were related to apoptotic processes, which corresponded to present or subsequent thymocyte apoptosis observed phenotypically. The gene expression profile was, however, not unambiguous since expression of apoptosis-related genes was both increased and decreased. Stimulation of glucocorticoid receptor signaling appeared to be a relevant underlying mechanism of action. These findings suggest that TBTO exerts its toxic effects on the thymus primarily by affecting apoptotic processes, but the possibility is discussed that this may in fact represent an early effect that precedes inhibition of cell proliferation. At the highest dose level tested, TBTO additionally repressed mitochondrial function and immune cell activation. Our in vitro toxicogenomics approach thus identified several cellular and molecular targets of TBTO that may mediate the toxicity towards thymocytes and thereby its immunosuppressive effects

Radiation-induced apoptosis

International Nuclear Information System (INIS)

Ohyama, Harumi

1995-01-01

Apoptosis is an active process of gene-directed cellular self-destruction that can be induced in many cell types via numerous physiological and pathological stimuli. We found that interphasedeath of thymocytes is a typical apoptosis showing the characteristic features of apoptosis including cell shrinkage, chromatin condensation and DNA degradation. Moderate dose of radiation induces extensive apoptosis in rapidly proliferating cell population such as the epithelium of intestinal crypt. Recent reports indicate that the ultimate form of radiation-induced mitotic death in several cells is also apoptosis. One of the hallmarks of apoptosis is the enzymatic internucleosomal degradation of chromatin DNA. We identified an endonuclease responsible for the radiation-induced DNA degradation in rat thymocytes. The death-sparing effects of interrupting RNA and protein synthesis suggested a cell genetic program for apoptosis. Apoptosis of thymocytes initiated by DNA damage, such as radiation and radio mimetic substance, absolutely requires the protein of p53 cancer suppresser gene. The cell death induced by glucocorticoid, or aging, has no such requirement. Expression of oncogene bcl-2 rescues cells from the apoptosis. Massive apoptosis in radiosensitive cells induced by higher dose radiation may be fatal. It is suggested that selective apoptotic elimination of cells would play an important role for protection against carcinogenesis and malformation through removal of cells with unrepaired radiation-induced DNA damages. Data to evaluate the significance of apoptosis in the radiation risk are still poor. Further research should be done in order to clarify the roles of the cell death on the acute and late effects of irradiation. (author)

Restricted expression of recombination activating gene (RAG-1) in mouse lymphoid tissues

International Nuclear Information System (INIS)

Yamamoto, Akihito; Fujinaga, Hiroyuki; Hamatani, Kiyohiro; Atsuta, Mitsuru.

1993-03-01

In an attempt to determine the distribution of recombinase activity in the mouse thymus, spleen, and lymph nodes, we used the in situ hybridization method to examine the expression of the recombination activating genes RAG-1 and RAG-2. Expression of RAG-1 was found in most cortical thymocytes but not in the majority of medullary thymocytes. Although hybridization signals of RAG-2 were not as intense as those of RAG-1, the localization of RAG-2 transcripts was similar to that of RAG-1. In the spleen, expression of RAG-1 was found only in limited cells near the splenic sinus, and the majority of the cells within the follicle were negative for RAG-1 transcript. In nude mice, RAG-1-expressing cells were detected in the same regions, which suggests that in situ hybridization signals of RAG-1 in the spleen are due to the cells of B-cell origin. In the lymph nodes, expression of RAG-1 was found only in the medullary region. Expression of RAG-2 transcript in the spleen and the lymph nodes, if any, was too faint to allow determination of the specific localization. These results suggest that most of the cortical thymocytes and some cells in the spleen are capable of rearranging T-cell receptor genes and immunoglobulin genes, respectively, but the possible involvement of the RAG-1 transcript in RAG-1-positive cells of the spleen and the lymph nodes in functions other than the rearrangement of genes could not be ruled out. (author)

Syngeneic transplantation in aplastic anemia: pre-transplant conditioning and peripheral blood are associated with improved engraftment: an observational study on behalf of the Severe Aplastic Anemia and Pediatric Diseases Working Parties of the European Group for Blood and Marrow Transplantation

Science.gov (United States)

Gerull, Sabine; Stern, Martin; Apperley, Jane; Beelen, Dietrich; Brinch, Lorentz; Bunjes, Donald; Butler, Andrew; Ganser, Arnold; Ghavamzadeh, Ardeshir; Koh, Mickey B; Komarnicki, Mieczyslaw; Kröger, Nicolaus; Maertens, Johan; Maschan, Alexei; Peters, Christina; Rovira, Montserrat; Sengeløv, Henrik; Socié, Gerard; Tischer, Johanna; Oneto, Rosi; Passweg, Jakob; Marsh, Judith

2013-01-01

Aplastic anemia is usually treated with immunosuppression or allogeneic transplant, depending on patient and disease characteristics. Syngeneic transplant offers a rare treatment opportunity with minimal transplant-related mortality, and offers an insight into disease mechanisms. We present here a retrospective analysis of all syngeneic transplants for aplastic anemia reported to the European Group for Blood and Marrow Transplantation. Between 1976 and 2009, 88 patients received 113 transplants. Most transplants (n=85) were preceded by a conditioning regimen, 22 of these including anti-thymocyte globulin. About half of transplants with data available (39 of 86) were followed by posttransplant immunosuppression. Graft source was bone marrow in the majority of cases (n=77). Transplant practice changed over time with more transplants with conditioning and anti-thymocyte globulin as well as peripheral blood stem cells performed in later years. Ten year overall survival was 93% with 5 transplant-related deaths. Graft failure occurred in 32% of transplants. Risk of graft failure was significantly increased in transplants without conditioning, and with bone marrow as graft source. Lack of posttransplant immunosuppression also showed a trend towards increased risk of graft failure, while anti-thymocyte globulin did not have an influence. In summary, syngeneic transplant is associated with a significant risk of graft failure when no conditioning is given, but has an excellent long-term outcome. Furthermore, our comparatively large series enables us to recommend the use of pre-transplant conditioning rather than not and possibly to prefer peripheral blood as a stem cell source. PMID:23894010

Thyroid Stimulating Immunoglobulin Bioassay Using Cultured Human Thyroid Cells; A Simplified Micromethod

International Nuclear Information System (INIS)

Lee, Myung Chul; Chung, June Key; Cho, Bo Youn; Koh, Chang Soon; Lee, Moon Ho; Ahn, Il Min; Ahn, Hee Kwon

1985-01-01

The activation of adenylate cyclase of human thymocytes in primary cell culture and the release of c-AMP into the medium are used to detect b-TSH and TSAb in sera of patients with autoimmune thyroid disease. Sera of patients are used directly as a part of cell culture without immunoglobulin precipitation. In the above TSI bioassay, TSAb pooled serum show c-AMP concentration between that of 1 mU/ml and 10 mU/ml b-TSH but normal control pooled serum doesn't show any detectable c-AMP response. Ninety five percent of untreated Graves' patients shows TSAb activity above normal range, 20% of Hashimoto's and 363/0 of euthyroid Graves' patients show detectable TSAb activity.

Selective inhibition of B lymphocytes in TBTC-treated human bone marrow long-term culture.

NARCIS (Netherlands)

Carfi', M.; Bowe, G.; Pieters, R.; Gribaldo, L.

2010-01-01

Tributyltin chloride (TBTC) is well known for its immunotoxic effect, in particular towards immature thymocytes. TBTC is also known to induce adipocyte differentiation in primary human bone marrow cultures, which is reflected in the decrease in a number of adipocyte-derived cytokines, chemokines and

Sphingosine-1-phosphate/sphingosine-1-phosphate receptor 1 signaling is required for migration of naive human T cells from the thymus to the periphery

NARCIS (Netherlands)

Resop, Rachel S.; Douaisi, Marc; Craft, Joshua; Jachimowski, Loes C. M.; Blom, Bianca; Uittenbogaart, Christel H.

2016-01-01

The mechanisms that govern the egress of mature thymocytes from the human thymus to the periphery remain understudied yet are of utmost importance to the field of basic immunology, as well as T-cell reconstitution in various immunodeficiencies. We examined the expression and function of

Experiment list: SRX099393 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 955772,97.5,10.9,675 GSM803121: input DNA Ikaros knockout chromatin preleukemic stage1 source_name=mouse Ik knock...out DP thymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=D

Experiment list: SRX099399 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available 963046,98.0,11.7,694 GSM803127: input DNA Ikaros knockout chromatin preleukemic stage2 source_name=mouse Ik knock...out DP thymocytes || genetic background=C57BL/6 x129S4/SvJae || genotype=Ikaros knockout || cell type=D

Phyllosilicate Detection and Uncertainty from Thermal Infrared Data in the Vicinity of the Nili Fossae

Science.gov (United States)

McDowell, M. L.; Hamilton, V. E.

2007-03-01

We examine TIR data from THEMIS and TES in areas identified by OMEGA as containing phyllosilicates. Our investigation will help to constrain phyllosilicate detection limits in TES data and likely surface abundances on Mars.

Viking Lander 2 Anniversary

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] This portion of a daytime IR image covers the Viking 2 landing site (shown with the X). The second landing on Mars took place September 3, 1976 in Utopia Planitia. The exact location of Lander 2 is not as well established as Lander 1 because there were no clearly identifiable features in the lander images as there were for the site of Lander 1. The Utopia landing site region contains pedestal craters, shallow swales and gentle ridges. The crater Goldstone was named in honor of the Tracking Station in the desert of California. The two Viking Landers operated for over 6 years (nearly four martian years) after landing. This one band IR (band 9 at 12.6 microns) image shows bright and dark textures, which are primarily due to differences in the abundance of rocks on the surface. The relatively cool (dark) regions during the day are rocky or indurated materials, fine sand and dust are warmer (bright). Many of the temperature variations are due to slope effects, with sun-facing slopes warmer than shaded slopes. The dark rings around several of the craters are due to the presence of rocky (cool) material ejected from the crater. These rocks are well below the resolution of any existing Mars camera, but THEMIS can detect the temperature variations they produce. Daytime temperature variations are produced by a combination of topographic (solar heating) and thermophysical (thermal inertia and albedo) effects. Due to topographic heating the surface morphologies seen in THEMIS daytime IR images are similar to those seen in previous imagery and MOLA topography.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be

The thermal evolution of large water-rich asteroids

Science.gov (United States)

Schmidt, B. E.; Castillo, J. C.

2009-12-01

Water and heat played a significant role in the formation and evolution of large main belt asteroids, including 1 Ceres, 2 Pallas, and 24 Themis, for which there is now evidence of surficial water ice (Rivkin & Emery, ACM 2008). Shape measurements indicate some differentiation of Ceres’ interior, which, in combination with geophysical modeling, may indicate compositional layering in a core made up of anhydrous and hydrated silicate and a water ice mantle (Castillo-Rogez & McCord, in press, Icarus). We extend these interior models now to other large, possibly water-rich main belt asteroids, namely Pallas, at mean radius 272 km, and the Themis family parent body, at mean radius 150 km. The purpose of this study is to compare geophysical models against available constraints on the physical properties of these objects and to offer constraints on the origin of these objects. Pallas is the largest B-type asteroid. Its surface of hydrated minerals and recent constraint on its density, 2.4-2.8 g/cm3, seems to imply that water strongly affected its evolution (Schmidt et al., in press, Science). 24 Themis is the largest member of the Themis family that now counts about 580 members, including some of the main belt comets. The large member 90 Antiope has a density of about 1.2 g/cm3, while 24 Themis has a density of about 2.7 +/-1.3 g/cm3. The apparent contrast in the densities and spectral properties of the Themis family members may reflect a compositional layering in the original parent body. In the absence of tidal heating and with little accretional heat, the evolution of these small water-rich objects is a function of their initial composition and temperature. The latter depends on the location of formation (in the inner or outer solar system) and most importantly on the time and duration of accretion, which determines the amount of short-lived radioisotopes available for early internal activity. New accretional models suggest that planetesimals grew rapidly throughout

Milrem müüb araablastele roomiksõidukeid

Index Scriptorium Estoniae

2017-01-01

Eesti kaitsetööstusettevõte Milrem sõlmis lepingu Araabia Ühendemiraatide suurima kaitsetööstusettevõttega IGG Aselsan Systems, et hakata riigi armeele müüma mehitamata roomiksõidukeid THeMIS

Immunologic glycosphingolipidomics and NKT cell development in mouse thymus

DEFF Research Database (Denmark)

Li, Yunsen; Thapa, Prakash; Hawke, David

2009-01-01

Invariant NKT cells are a hybrid cell type of Natural Killer cells and T cells, whose development is dependent on thymic positive selection mediated by double positive thymocytes through their recognition of natural ligands presented by CD1d, a nonpolymorphic, non-MHC, MHC-like antigen presenting...

Thymic nurse cells and thymic repopulation after whole body sublethal irradiation in mice

International Nuclear Information System (INIS)

Houben-Defresne, M.P.; Varlet, A.; Boniver, J.

1984-01-01

Thymic Nurse Cells (TNCs) are lymphoepithelial complexes which are thought to play a role in the early stages of the intrathymic differentiation pathway. Their repopulation kinetics were analyzed in mice after sublethal whole-body irradiation. Changes of the number of TNCs per thymus were parallel with the evolution of the whole thymocyte population. Particularly, a first wave of TNCs restoration was followed by a secondary depletion and a final recovery. This suggests that TNCs restoration is related to the proliferating progeny of intrathymic radioresistant thymocytes. When normal bone marrow cells were grafted intravenously after irradiation, no secondary depletion was found. This pattern of restoration was obviously related to thymic repopulation by cells which were derived from the inoculated bone marrow. Homing studies with FITC labelled bone marrow cells showed that inoculated bone marrow cells did not penetrate TNCs early after irradiation. Later on, when immigrant cells started to proliferate, they were found preferentially within TNCs before spreading in the whole thymus. (Auth.)

Analysis of TCRAD gene recombination: radio-induct rearrangement and signal joint structure

International Nuclear Information System (INIS)

Touvrey, C.

2005-09-01

We have shown that irradiation of pre-TCR-deficient CD3ε -/- mice restores thymocyte differentiation, by a p53-dependent and by a p53-independent pathway. Events normally associated during normal thymocyte development are dissociated in response to radiation exposure. Both of these pathways require LAT expression. Therefore, radiation exposure activates pre-TCR-like signals. TCRA gene rearrangement is induced following radiation exposure. The signal joints resulting from TCRA gene rearrangement have the same structure than those found in wild type mice. All signal joint analyzed in un-manipulated wild type mice do exhibit junctional diversity. This diversity results mainly from TdT activity. We present evidences that proteins involved in DNA repair and genomic stability participated in SJ formation. We propose that signal joint diversity is not an aberrant process but is a key feature of V(D)J recombination. All our work increases our understanding of molecular events associated with V(D)J recombination. (author)

Protective effect of alkali extract of Huangmo (AEHM) on immunological function in X-irradiated mice

International Nuclear Information System (INIS)

Ye Fei; Wu Congmei; Su Shijie; Cao Ruimin

1996-01-01

The male mice were given ip AEHM 5 mg/kg, wt/d before irradiation with 2.0 Gy X-rays for 3 days, and the changes of several immunological indexes were observed 24 h after X-irradiation. The results showed that AEHM significantly increased the numbers of splenocytes and thymocytes, the reaction of splenocytes to ConA and the spontaneous proliferation of thymocytes in irradiated mice, and decreased the fall of spleen and thymus. In addition, a tendency of the increases in the above indexes in the intact mice treated with AEHM was observed. Meanwhile, AEHM possessed similar radioprotective effect on immunological functions to polysaccharides of Ginseng. The results suggest that AEHM has not only a radioprotective effect on immunological functions in the irradiated mice, but also an enhancing effect on the defence functions in the intact mice. It is very hopeful that AEHM acted as immune-enhanced drug should be used in the clinic

Vaccination against feline immunodeficiency virus using fixed infected cells

NARCIS (Netherlands)

Horzinek, M.C.; Verschoor, E.J.; Vliet, A.L.W. van; Egberink, H.F.; Hesselink, W.; Alphen, W.E. van; Joosten, I.; Boog, C.J.P.; Ronde, A. de

1995-01-01

Crandell feline kidney cells and feline thymocytes, either feline immunodeficiency virus (FIV) infected or uninfected, were fixed with paraformaldehyde and used to vaccinate cats. The cells were mixed with a 30:70 water/mineral oil emulsion containing 250 mu g ml−1 N-acetyl-d-glucosaminyl-beta-(1

Influence of ionizing radiation on the plasma membrane proteins

International Nuclear Information System (INIS)

Dreval', V.I.

1992-01-01

The effect of ionizing radiation on the meat cattle thymocytes plasma membranes was studied. Using fluorescence quenching technique the effect of irradiation of proteins conformation was investigated. The influence of ionizing radiation on the plasma membranes was shown to be followed by changes of the protein structure-dynamic organization

Characterisation of mouse prothymocytes

NARCIS (Netherlands)

W.J.A. Boersma (Wim)

1982-01-01

textabstractIn this thesis, the study of growth kinetics of thymocytes in lethally irradiated mice as a means to characterise the early T-cell progenitors is described. Normal bone marrow cells were used as the source of hemopoietic cells. The experiments show that it is possible to obtain

Remnants of Lost Geology

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] In eastern Arabia Terra, remnants of a once vast layered terrain are evident as isolated buttes, mesas, and deeply-filled craters. The origin of the presumed sediments that created the layers is unknown, but those same sediments, now eroded, may be the source of the thick mantle of dust that covers much of Arabia Terra today.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 20.5, Longitude 50 East (310 West). 19 meter/pixel resolution.

Prenatal cadmium exposure produces persistent changes to thymus and spleen cell phenotypic repertoire as well as the acquired immune response

International Nuclear Information System (INIS)

Holásková, Ida; Elliott, Meenal; Hanson, Miranda L.; Schafer, Rosana; Barnett, John B.

2012-01-01

Cadmium (Cd) is a common environmental contaminant. Adult exposure to Cd alters the immune system, however, there are limited studies on the effects of prenatal exposure to Cd. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl 2 (10 ppm) and the effects on the immune system of the offspring were assessed at 20 weeks of age. Prenatal Cd exposure caused an increase in the percent of CD4 − CD8 − CD44 + CD25 − (DN1) thymocytes in both sexes and a decrease in the percent of CD4 − CD8 − CD44 − CD25 + (DN3) thymocytes in females. Females had an increase in the percent of splenic CD4 + T cells, CD8 + T cells, and CD45R/B220 + B cells and a decrease in the percent of NK cells and granulocytes (Gr-1 + ). Males had an increase in the percent of splenic CD4 + T cells and CD45R/B220 + B cells and a decrease in the percent of CD8 + T cells, NK cells, and granulocytes. The percentage of neutrophils and myeloid-derived suppressor cells were reduced in both sexes. The percent of splenic nTreg cells was decreased in all Cd-exposed offspring. Cd-exposed offspring were immunized with a streptococcal vaccine and the antibody response was determined. PC-specific serum antibody titers were decreased in Cd exposed female offspring but increased in the males. PspA-specific serum IgG titers were increased in both females and males compared to control animals. Females had a decrease in PspA-specific serum IgM antibody titers. Females and males had a decrease in the number of splenic anti-PspA antibody-secreting cells when standardized to the number of B cells. These findings demonstrate that very low levels of Cd exposure during gestation can result in long term sex-specific alterations on the immune system of the offspring. -- Highlights: ► Prenatal exposure to cadmium alters the immune system of 20 week old offspring. ► The percentage of DN1 and DN3 thymocytes was changed. ► Males and females had changed percentages of numerous splenic cell

Prenatal cadmium exposure produces persistent changes to thymus and spleen cell phenotypic repertoire as well as the acquired immune response

Energy Technology Data Exchange (ETDEWEB)

Holásková, Ida; Elliott, Meenal; Hanson, Miranda L.; Schafer, Rosana [Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506 (United States); Barnett, John B., E-mail: jbarnett@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University School of Medicine, Morgantown, WV 26506 (United States); Mary Babb Randolph Cancer Center, West Virginia University School of Medicine, Morgantown, WV 26506 (United States)

2012-12-01

Cadmium (Cd) is a common environmental contaminant. Adult exposure to Cd alters the immune system, however, there are limited studies on the effects of prenatal exposure to Cd. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at 20 weeks of age. Prenatal Cd exposure caused an increase in the percent of CD4{sup −}CD8{sup −}CD44{sup +}CD25{sup −} (DN1) thymocytes in both sexes and a decrease in the percent of CD4{sup −}CD8{sup −}CD44{sup −}CD25{sup +} (DN3) thymocytes in females. Females had an increase in the percent of splenic CD4{sup +} T cells, CD8{sup +} T cells, and CD45R/B220{sup +} B cells and a decrease in the percent of NK cells and granulocytes (Gr-1{sup +}). Males had an increase in the percent of splenic CD4{sup +} T cells and CD45R/B220{sup +} B cells and a decrease in the percent of CD8{sup +} T cells, NK cells, and granulocytes. The percentage of neutrophils and myeloid-derived suppressor cells were reduced in both sexes. The percent of splenic nTreg cells was decreased in all Cd-exposed offspring. Cd-exposed offspring were immunized with a streptococcal vaccine and the antibody response was determined. PC-specific serum antibody titers were decreased in Cd exposed female offspring but increased in the males. PspA-specific serum IgG titers were increased in both females and males compared to control animals. Females had a decrease in PspA-specific serum IgM antibody titers. Females and males had a decrease in the number of splenic anti-PspA antibody-secreting cells when standardized to the number of B cells. These findings demonstrate that very low levels of Cd exposure during gestation can result in long term sex-specific alterations on the immune system of the offspring. -- Highlights: ► Prenatal exposure to cadmium alters the immune system of 20 week old offspring. ► The percentage of DN1 and DN3 thymocytes was changed

The global armoured vehicles market / Dennis-P. Merklinghaus

Index Scriptorium Estoniae

Merklinghaus, Dennis-P.

2017-01-01

Ülevaade erinevate maailma riikide kaitsekulutustest, investeeringutest soomusmasinatesse ja sõjatehnikasse. Teiste riikide hulgas tutvustatakse ka Eesti kaitseväe käsutuses olevaid soomusmasinaid ning Milremi loodud relvasüsteemi THeMIS ja mehitamata roomiksõidukit UGV

Effects of an induced adenosine deaminase deficiency on T-cell differentiation in the rat

International Nuclear Information System (INIS)

Barton, R.W.

1985-01-01

Inherited deficiency of the enzyme adenosine deaminase (ADA) has been found in a significant proportion of patients with severe combined immunodeficiency disease and inherited defect generally characterized by a deficiency of both B and T cells. Two questions are central to understanding the pathophysiology of this disease: (1) at what stage or stages in lymphocyte development are the effects of the enzyme deficiency manifested; (2) what are the biochemical mechanisms responsible for the selective pathogenicity of the lymphoid system. We have examined the stage or stages of rat T-cell development in vivo which are affected by an induced adenosine deaminase deficiency using the ADA inhibitors, erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and 2'-deoxycoformycin (DCF). In normal rats given daily administration of an ADA inhibitor, cortical thymocytes were markedly depleted; peripheral lymphocytes and pluripotent hemopoietic stem cells (CFU-S) all were relatively unaffected. Since a deficiency of ADA affects lymphocyte development, the regeneration of cortical and medullary thymocytes and their precursors after sublethal irradiation was used as a model of lymphoid development. By Day 5 after irradiation the thymus was reduced to 0.10-0.5% of its normal size; whereas at Days 9 and 14 the thymus was 20-40% and 60-80% regenerated, respectively. When irradiated rats were given daily parenteral injections of the ADA inhibitor plus adenosine or deoxyadenosine, thymus regeneration at Days 9 and 14 was markedly inhibited, whereas the regeneration of thymocyte precursors was essentially unaffected. Thymus regeneration was at least 40-fold lower than in rats given adenosine or deoxyadenosine alone. Virtually identical results were obtained with both ADA inhibitors, EHNA and DCF

Characterisation of mouse prothymocytes

NARCIS (Netherlands)

Boersma, W.J.A.

1982-01-01

In this thesis, the study of growth kinetics of thymocytes in lethally irradiated mice as a means to characterise the early T-cell progenitors is described. Normal bone marrow cells were used as the source of hemopoietic cells. The experiments show that it is possible to obtain information on T-cell

Evidence for recent climate fluctuations on Mars - from cold to colder

Science.gov (United States)

Christensen, P. R.

2003-12-01

Evidence from a variety of sources suggests that Mars has a significant water inventory. However, it appears that this inventory has been frozen throughout much of Mars history. The THEMIS camera has detected layers of exposed olivine-rich basalt 4.5 km below the surface in Ganges Chasma, indicating that this region has not experienced significant surface or sub-surface water at any time in its history. In addition, THEMIS has not detected mineralogical evidence for carbonate layers at 100-m scales, despite the discovery by the MGS TES of minor carbonate in the martian dust. THEMIS has, however, shown evidence for extensive ice deposits in the mid- to high-latitude regions, some of which show evidence for recent downslope flow. THEMIS images show that mantles on pole-facing slopes occur preferentially in mid-latitudes and are interpreted to be remnants of once-extensive snows deposited during recent periods of high obliquity. Melting of these deposits during intervening warmer periods may form the young gullies that are also observed at these latitudes. High (greater than 50 percent volume) water-ice abundances have been found in the upper few meters at high-latitudes by the Odyssey Gamma-Ray and Neutron Spectrometer Teams, suggesting that this ice also formed at the surface rather than in pores. A pervasive surface mantle found from 30 to 50° in both hemispheres has been interpreted by Mustard et al. (2001) to result from ice-cemented soils that have formed recently and are currently being devolatilized. The poleward transition from a dissected to continuous surface on this mantle corresponds to a sharp increase in near-surface ice abundance seen by the GRS, suggesting that the mid-latitude portion of these mantles may be the same ice-rich material but whose upper few meters have been thoroughly desiccated. Together these observations suggest extensive mid-latitude surface ice deposits that come and go on time scales of 50,000 to several million years. Limited

Depletion of naive CD4 T cells by CXCR4-using HIV-1 variants occurs mainly through increased T-cell death and activation

NARCIS (Netherlands)

Hazenberg, Mette D.; Otto, Sigrid A.; Hamann, Dörte; Roos, Marijke Th L.; Schuitemaker, Hanneke; de Boer, Rob J.; Miedema, Frank

2003-01-01

Objective: Using SCID-Hu mice models and in vitro culture systems, it has been shown that syncytium inducing/CXCR4 using (X4) HIV-1 variants affect thymic function through infection and killing of CXCR4 thymocytes. The effect of X4-emergence on naive, memory and effector T-cell subset kinetics in

Ionizing radiation and autoimmunity: Induction of autoimmune disease in mice by high dose fractionated total lymphoid irradiation and its prevention by inoculating normal T cells

International Nuclear Information System (INIS)

Sakaguchi, N.; Sakaguchi, S.; Miyai, K.

1992-01-01

Ionizing radiation can functionally alter the immune system and break self-tolerance. High dose (42.5 Gy), fractionated (2.5 Gy 17 times) total lymphoid irradiation (TLI) on mice caused various organ-specific autoimmune diseases, such as gastritis, thyroiditis, and orchitis, depending on the radiation dosages, the extent of lymphoid irradiation, and the genetic background of the mouse strains. Radiation-induced tissue damage is not the primary cause of the autoimmune disease because irradiation of the target organs alone failed to elicit the autoimmunity and shielding of the organs from irradiation was unable to prevent it. In contrast, irradiation of both the thymus and the peripheral lymphoid organs/tissues was required for efficient induction of autoimmune disease by TLI. TLI eliminated the majority of mature thymocytes and the peripheral T cells for 1 mo, and inoculation of spleen cell, thymocyte, or bone marrow cell suspensions (prepared from syngeneic nonirradiated mice) within 2 wk after TLI effectively prevented the autoimmune development. Depletion of T cells from the inocula abrogated the preventive activity. CD4 + T cells mediated the autoimmune prevention but CD8 + T cells did not. CD4 + T cells also appeared to mediate the TLI-induced autoimmune disease because CD4 + T cells from disease-bearing TLI mice adoptively transferred the autoimmune disease to syngeneic naive mice. Taken together, these results indicate that high dose, fractionated ionizing radiation on the lymphoid organs/tissues can cause autoimmune disease by affecting the T cell immune system, rather than the target self-Ags, presumably by altering T cell-dependent control of self-reactive T cells. 62 refs., 9 figs., 2 tabs

Protective specific immunity induced by doxorubicin plus TNF-alpha combination treatment of EL4 lymphoma-bearing C57BL/6 mice.

Science.gov (United States)

Ehrke, M J; Verstovsek, S; Maccubbin, D L; Ujházy, P; Zaleskis, G; Berleth, E; Mihich, E

2000-07-01

The therapeutic efficacy of a single (day 8), moderate dose (4 mg/kg, i.v.) of doxorubicin (DOX, Adriamycin) combined with recombinant human TNF-alpha (3 different doses and 5 different schedules, i.v.) was evaluated in C57BL/6 mice bearing an implant (s.c.) of the DOX-sensitive, TNF-alpha-resistant EL4 lymphoma. In parallel to monitoring survival, the levels of several host anti-tumor cytolytic effector functions of splenocytes and thymocytes were evaluated throughout the treatment period and in long-term survivors (LTS). DOX treatment alone resulted in a moderate (approx. 20%) increase in life span but no cures. TNF-alpha alone, at any tested dose or schedule, had little or no positive effect on survival. The combinations of DOX and TNF-alpha were only slightly better than DOX alone with respect to the time to death of mice that died (approx. 29% increase); however, each of the combinations involving 1,000 U TNF-alpha/injection produced a fraction (20% to 80%) of LTS. The host defense activities examined included those of splenic and thymic cytolytic T lymphocytes (CTL) and lymphokine-activated killer cells as well as splenic tumoricidal macrophages. Although most activities were modulated by tumor growth and/or treatment, only CTL responsiveness appeared to correlate with survival. CTL activity in the treated groups with LTS was significantly higher than in control groups late in the treatment period. Finally, ex vivo analyses of splenocytes and thymocytes together with the rejection of implanted tumor at 17 months established that LTS displayed specific long-term immune memory. Copyright 2000 Wiley-Liss, Inc.

THE CONCEPT OF JUSTICE (‘DIKE’ AND ‘THEMIS’ AS IT IS REVEALED BY THE TEACHINGS OF NEAGOE BASARAB TO HIS SON THEODOSIE

Directory of Open Access Journals (Sweden)

FLORENTINA GRIGORE

2016-05-01

Full Text Available This paper is an inquiry into the problems concerning the construction of the legal system: the theme represented by human quality called to building and completing the legal system. The human being is ontologically placed between Dike / Legal Justice and Themis / Transcendent Justice. The person called to judge is the link between two different ontological orders: the order of the Absolute, of Themis, and the order of the Relative, of Dike. This person is the one who guides Themis to perform Dike, in order to do Justice in coincidence with Legal Justice. The Teachings of Neagoe Basarab to his Son Theodosie was written at almost the same time as The Prince by Machiavelli. If we look at Machiavelli’s work and that of Neagoe Basarab, we are able to see two distinct ways to build and give legitimacy to the legal system. The Teachings do not approach a sophisticated architecture of the legal system, with hierarchies and complex abilities. The discourse about justice especially implies the moral valuation of the people summoned to judge and to do what is right. This work is about the foundation of the legal system regardless of its structure. And the foundation of the system is the person called to judge in such a way that Δίκη should coincide with Θέμις. From Machiavelli we have a different vision about Justice and the Legal system: he focuses on the system and not on the person who performs those functions within the system.

Arsinoes Chaos

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] At the easternmost end of Valles Marineris, a rugged, jumbled terrain known as chaos displays a stratigraphy that could be described as precarious. Perched on top of the jumbled blocks is another layer of sedimentary material that is in the process of being eroded off the top. This material is etched by the wind into yardangs before it ultimately is stripped off to reveal the existing chaos.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude -7.8, Longitude 19.1 East (340.9 West). 19 meter/pixel resolution.

Source of the dayside cusp aurora.

Science.gov (United States)

Mende, S B; Frey, H U; Angelopoulos, V

2016-08-01

Monochromatic all-sky imagers at South Pole and other Antarctic stations of the Automatic Geophysical Observatory chain recorded the aurora in the region where the Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites crossed the dayside magnetopause. In several cases the magnetic field lines threading the satellites when mapped to the atmosphere were inside the imagers' field of view. From the THEMIS magnetic field and the plasma density measurements, we were able to locate the position of the magnetopause crossings and map it to the ionosphere using the Tsyganenko-96 field model. Field line mapping is reasonably accurate on the dayside subsolar region where the field is strong, almost dipolar even though compressed. From these coordinated observations, we were able to prove that the dayside cusp aurora of high 630 nm brightness is on open field lines, and it is therefore direct precipitation from the magnetosheath. The cusp aurora contained significant highly structured N 2 + 427.8 nm emission. The THEMIS measurements of the magnetosheath particle energy and density taken just outside the magnetopause compared to the intensity of the structured N 2 + 427.8 nm emissions showed that the precipitating magnetosheath particles had to be accelerated. The most likely electron acceleration mechanism is by dispersive Alfvén waves propagating along the field line. Wave-accelerated suprathermal electrons were seen by FAST and DMSP. The 427.8 nm wavelength channel also shows the presence of a lower latitude hard-electron precipitation zone originating inside the magnetosphere.

The requirement for pre-TCR during thymic differentiation enforces a developmental pause that is essential for V-DJβ rearrangement.

Directory of Open Access Journals (Sweden)

Karen S Hathcock

Full Text Available T cell development occurs in the thymus and is critically dependent on productive TCRβ rearrangement and pre-TCR expression in DN3 cells. The requirement for pre-TCR expression results in the arrest of thymocytes at the DN3 stage (β checkpoint, which is uniquely permissive for V-DJβ recombination; only cells expressing pre-TCR survive and develop beyond the DN3 stage. In addition, the requirement for TCRβ rearrangement and pre-TCR expression enforces suppression of TCRβ rearrangement on a second allele, allelic exclusion, thus ensuring that each T cell expresses only a single TCRβ product. However, it is not known whether pre-TCR expression is essential for allelic exclusion or alternatively if allelic exclusion is enforced by developmental changes that can occur in the absence of pre-TCR. We asked if thymocytes that were differentiated without pre-TCR expression, and therefore without pause at the β checkpoint, would suppress all V-DJβ rearrangement. We previously reported that premature CD28 signaling in murine CD4(-CD8(- (DN thymocytes supports differentiation of CD4(+CD8(+ (DP cells in the absence of pre-TCR expression. The present study uses this model to define requirements for TCRβ rearrangement and allelic exclusion. We demonstrate that if cells exit the DN3 developmental stage before TCRβ rearrangement occurs, V-DJβ rearrangement never occurs, even in DP cells that are permissive for D-Jβ and TCRα rearrangement. These results demonstrate that pre-TCR expression is not essential for thymic differentiation to DP cells or for V-DJβ suppression. However, the requirement for pre-TCR signals and the exclusion of alternative stimuli such as CD28 enforce a developmental "pause" in early DN3 cells that is essential for productive TCRβ rearrangement to occur.

Prenatal exposure of mice to diethylstilbestrol disrupts T-cell differentiation by regulating Fas/Fas ligand expression through estrogen receptor element and nuclear factor-κB motifs.

Science.gov (United States)

Singh, Narendra P; Singh, Udai P; Nagarkatti, Prakash S; Nagarkatti, Mitzi

2012-11-01

Prenatal exposure to diethylstilbestrol (DES) is known to cause altered immune functions and increased susceptibility to autoimmune disease in humans. In the current study, we investigated the effect of prenatal exposure to DES on thymocyte differentiation involving apoptotic pathways. Prenatal DES exposure caused thymic atrophy, apoptosis, and up-regulation of Fas and Fas ligand (FasL) expression in thymocytes. To examine the mechanism underlying DES-mediated regulation of Fas and FasL, we performed luciferase assays using T cells transfected with luciferase reporter constructs containing full-length Fas or FasL promoters. There was significant luciferase induction in the presence of Fas or FasL promoters after DES exposure. Further analysis demonstrated the presence of several cis-regulatory motifs on both Fas and FasL promoters. When DES-induced transcription factors were analyzed, estrogen receptor element (ERE), nuclear factor κB (NF-κB), nuclear factor of activated T cells (NF-AT), and activator protein-1 motifs on the Fas promoter, as well as ERE, NF-κB, and NF-AT motifs on the FasL promoter, showed binding affinity with the transcription factors. Electrophoretic mobility-shift assays were performed to verify the binding affinity of cis-regulatory motifs of Fas or FasL promoters with transcription factors. There was shift in mobility of probes (ERE or NF-κB2) of both Fas and FasL in the presence of nuclear proteins from DES-treated cells, and the shift was specific to DES because these probes failed to shift their mobility in the presence of nuclear proteins from vehicle-treated cells. Together, the current study demonstrates that prenatal exposure to DES triggers significant alterations in apoptotic molecules expressed on thymocytes, which may affect T-cell differentiation and cause long-term effects on the immune functions.

DNA-radiosensitivity and repair in mammolian cells

International Nuclear Information System (INIS)

Proskuryakov, S.Ya.; Ivannik, B.P.; Ryabchenko, N.I.

1979-01-01

Determination was made of the formation and repair of single-stranded DNA breaks (SB) in cells of rat thymus and liver and Ehrlich's ascites tumor (EAT) with the use of the method of low-gradient viscosimetry of alkaline cell lysates. The radiochemical yield of single-stranded breaks (Gsub(SB)) induced by irradiation of animals is 41.2 eV/break for hepatocytes, 96.8 eV/break, for thymocytes, and 129.7 eV/break, for EAT cells. The half-recovery time of single-stranded DNA breaks for cells of thymus and EAT exposed in vivo is 16.0 and 5.1 s -1 , correspondingly. In hepatocytes exposed in vivo and in vitro no repairs occurs for 3 h. Under conditions of inhibition of SB repair, when suspensions of thymocytes and hepatocytes were exposed in vitro at 4 deg C, Gsub(SB) is 35.5 and 38.7 eV/break, respectively. The analysis of the data obtained prompts the conclusion that under in vivo conditions, there is a correlation between DNA radiosensitivity and the rate of repair processes

Two different mutations in the envelope protein of feline immunodeficiency virus allow the virus to escape from neutralization by feline serum antibodies.

NARCIS (Netherlands)

C.H.J. Siebelink (Kees); M.L. Bosch (Marnix); G.F. Rimmelzwaan (Guus); R.H. Meloen; A.D.M.E. Osterhaus (Albert)

1995-01-01

textabstractViral progeny of two molecular clones of feline immunodeficiency virus (FIV), 19k1 and 19k32, were tested in a virus neutralization assay. In this assay the infection of thymocytes with FIV19k1 was neutralized by serum S1422, derived from an SPF cat 22 weeks after infection with FIV19k1.

Phospholipid metabolism in lymphoid cells at delayed periods following sublethal γ-irradiation of rats

International Nuclear Information System (INIS)

Novoselova, E.G.

1991-01-01

Dynamics of phospholipid metabolism in rat thymocytes and bone marrow cells was studied 1-6 months after fractionated irradiation. The rate of total and individual lipid synthesis was shown to increase in the exposed cells. The rate of lipid synthesis increased 1 and 2 months after irradiation and was normalized 3 and 6 months after irradiation

CCRL1/ACKR4 is expressed in key thymic microenvironments but is dispensable for T lymphopoiesis at steady state in adult mice

DEFF Research Database (Denmark)

Lucas, Beth; White, Andrea J.; Ulvmar, Maria H.

2015-01-01

Thymus colonisation and thymocyte positioning are regulated by interactions between CCR7 and CCR9, and their respective ligands, CCL19/CCL21 and CCL25. The ligands of CCR7 and CCR9 also interact with the atypical receptor CCRL1 (also known as ACKR4), which is expressed in the thymus and has recen...

Estonia's Milrem enters into partnership with UAE's defence industry

Index Scriptorium Estoniae

2017-01-01

Eesti kaitsetööstusettevõte Milrem osales Araabia Ühendemiraatides kaitsetööstusettevõtete messil ja sõlmis lepingu Araabia Ühendemiraatide suurima kaitsetööstusettevõttega IGG Aselsan Systems, et hakata riigi armeele müüma mehitamata roomiksõidukeid THeMIS

NKT sublineage specification and survival requires the ubiquitin-modifying enzyme TNFAIP3/A20.

Science.gov (United States)

Drennan, Michael B; Govindarajan, Srinath; Verheugen, Eveline; Coquet, Jonathan M; Staal, Jens; McGuire, Conor; Taghon, Tom; Leclercq, Georges; Beyaert, Rudi; van Loo, Geert; Lambrecht, Bart N; Elewaut, Dirk

2016-09-19

Natural killer T (NKT) cells are innate lymphocytes that differentiate into NKT1, NKT2, and NKT17 sublineages during development. However, the signaling events that control NKT sublineage specification and differentiation remain poorly understood. Here, we demonstrate that the ubiquitin-modifying enzyme TNFAIP3/A20, an upstream regulator of T cell receptor (TCR) signaling in T cells, is an essential cell-intrinsic regulator of NKT differentiation. A20 is differentially expressed during NKT cell development, regulates NKT cell maturation, and specifically controls the differentiation and survival of NKT1 and NKT2, but not NKT17, sublineages. Remaining A20-deficient NKT1 and NKT2 thymocytes are hyperactivated in vivo and secrete elevated levels of Th1 and Th2 cytokines after TCR ligation in vitro. Defective NKT development was restored by compound deficiency of MALT1, a key downstream component of TCR signaling in T cells. These findings therefore show that negative regulation of TCR signaling during NKT development controls the differentiation and survival of NKT1 and NKT2 cells. © 2016 Drennan et al.

Spreading Speed of Magnetopause Reconnection X-Lines Using Ground-Satellite Coordination

Science.gov (United States)

Zou, Ying; Walsh, Brian M.; Nishimura, Yukitoshi; Angelopoulos, Vassilis; Ruohoniemi, J. Michael; McWilliams, Kathryn A.; Nishitani, Nozomu

2018-01-01

Conceptual and numerical models predict that magnetic reconnection starts at a localized region and then spreads out of the reconnection plane. At the Earth's magnetopause this spreading would occur primarily in local time along the boundary. Different simulations have found the spreading to occur at different speeds such as the Alfvén speed and speed of the current carriers. We use conjugate Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft and Super Dual Auroral Radar Network (SuperDARN) radar measurements to observationally determine the X-line spreading speed at the magnetopause. THEMIS probes the reconnection parameters locally, and SuperDARN tracks the reconnection development remotely. Spreading speeds under different magnetopause boundary conditions are obtained and compared with model predictions. We find that while spreading under weak guide field could be explained by either the current carriers or the Alfvén waves, spreading under strong guide field is consistent only with the current carriers.

Gigas Meets Ulysses

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 9 July 2003Roughly halfway between the great volcanoes of Olympus Mons and Pavonis Mons, the graben (troughs) of Ulysses Fossae intersect with the furrows of Gigas (gigantic) Sulci. A clear time sequence is evident: first came the formation of the sulci terrain (to the left), which then was fractured by graben radial to Olympus Mons, followed by flooding of lava. All but the deepest graben are filled by lava in the topographic low between the two volcanic rises.Image information: VIS instrument. Latitude 11.8, Longitude 234.3 East (125.7 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

A Tale of Two Craters

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] In western Acidalia, two craters of similar size (a few km's) dramatically display the effects of geologic activity. The younger one on the left has been left relatively well preserved, retaining a sharp rim crest, a classic bowl shape, and a clearly defined ejecta blanket. The older one on the right likely has experienced a flood of lava that covered over the ejecta and filled in the bowl (note the breach in the rim). Its rim crest has been worn down by a multitude of subsequent impacts.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.Image information: VIS instrument. Latitude 35.9, Longitude 311.1 East (48.9 West). 19 meter/pixel resolution.

Effect of ionizing radiation on Ca2+-ATPase and Mg2+-ATPase: the role of ligands

International Nuclear Information System (INIS)

Dreval', V.I.

1994-01-01

The change of Ca 2+ -ATPase and Mg 2+ -ATPase activity in plasma membranes of thymocytes irradiated with doses of 10 2 , 10 3 and 10 4 Gy in the presence of Ca 2+ , Mg 2+ and ATP was studied. Stabilizing effect of Ca 2+ and Mg 2+ on Ca 2+ -ATPase and ATP on Mg 2+ -ATPase under irradiation was established

Arsia Mons by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 22 June 2004 This pair of images shows part of Arsia Mons. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -19.6, Longitude 241.9 East (118.1 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

Albor Tholus by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 21 June 2004 This pair of images shows part of Albor Tholus. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude 17.6, Longitude 150.3 East (209.7 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

Channel by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 17 June 2004 This pair of images shows part of a small channel. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude 19.8, Longitude 141.5 East (218.5 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

Noctus Labyrinthus by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 25 June 2004 This pair of images shows part of Noctus Labyrinthus. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -9.6, Longitude 264.5 East (95.5 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

Crater Ejecta by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 24 June 2004 This pair of images shows a crater and its ejecta. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -9, Longitude 164.2 East (195.8 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

Ius Chasma by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 18 June 2004 This pair of images shows part of Ius Chasma. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -1, Longitude 276 East (84 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at

Gusev Crater by Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 23 June 2004 This pair of images shows part of Gusev Crater. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -14.5, Longitude 175.5 East (184.5 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

Lomonosov Crater, Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 16 June 2004 This pair of images shows part of Lomonosov Crater. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude 64.9, Longitude 350.7 East (9.3 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project

DKK1 mediated inhibition of Wnt signaling in postnatal mice leads to loss of TEC progenitors and thymic degeneration.

Directory of Open Access Journals (Sweden)

Masako Osada

2010-02-01

Full Text Available Thymic epithelial cell (TEC microenvironments are essential for the recruitment of T cell precursors from the bone marrow, as well as the subsequent expansion and selection of thymocytes resulting in a mature self-tolerant T cell repertoire. The molecular mechanisms, which control both the initial development and subsequent maintenance of these critical microenvironments, are poorly defined. Wnt signaling has been shown to be important to the development of several epithelial tissues and organs. Regulation of Wnt signaling has also been shown to impact both early thymocyte and thymic epithelial development. However, early blocks in thymic organogenesis or death of the mice have prevented analysis of a role of canonical Wnt signaling in the maintenance of TECs in the postnatal thymus.Here we demonstrate that tetracycline-regulated expression of the canonical Wnt inhibitor DKK1 in TECs localized in both the cortex and medulla of adult mice, results in rapid thymic degeneration characterized by a loss of DeltaNP63(+ Foxn1(+ and Aire(+ TECs, loss of K5K8DP TECs thought to represent or contain an immature TEC progenitor, decreased TEC proliferation and the development of cystic structures, similar to an aged thymus. Removal of DKK1 from DKK1-involuted mice results in full recovery, suggesting that canonical Wnt signaling is required for the differentiation or proliferation of TEC populations needed for maintenance of properly organized adult thymic epithelial microenvironments.Taken together, the results of this study demonstrate that canonical Wnt signaling within TECs is required for the maintenance of epithelial microenvironments in the postnatal thymus, possibly through effects on TEC progenitor/stem cell populations. Downstream targets of Wnt signaling, which are responsible for maintenance of these TEC progenitors may provide useful targets for therapies aimed at counteracting age associated thymic involution or the premature thymic

Genomic organization and the tissue distribution of alternatively spliced isoforms of the mouse Spatial gene

Directory of Open Access Journals (Sweden)

Mattei Marie-Geneviève

2004-07-01

Full Text Available Abstract Background The stromal component of the thymic microenvironment is critical for T lymphocyte generation. Thymocyte differentiation involves a cascade of coordinated stromal genes controlling thymocyte survival, lineage commitment and selection. The "Stromal Protein Associated with Thymii And Lymph-node" (Spatial gene encodes a putative transcription factor which may be involved in T-cell development. In the testis, the Spatial gene is also expressed by round spermatids during spermatogenesis. Results The Spatial gene maps to the B3-B4 region of murine chromosome 10 corresponding to the human syntenic region 10q22.1. The mouse Spatial genomic DNA is organised into 10 exons and is alternatively spliced to generate two short isoforms (Spatial-α and -γ and two other long isoforms (Spatial-δ and -ε comprising 5 additional exons on the 3' site. Here, we report the cloning of a new short isoform, Spatial-β, which differs from other isoforms by an additional alternative exon of 69 bases. This new exon encodes an interesting proline-rich signature that could confer to the 34 kDa Spatial-β protein a particular function. By quantitative TaqMan RT-PCR, we have shown that the short isoforms are highly expressed in the thymus while the long isoforms are highly expressed in the testis. We further examined the inter-species conservation of Spatial between several mammals and identified that the protein which is rich in proline and positive amino acids, is highly conserved. Conclusions The Spatial gene generates at least five alternative spliced variants: three short isoforms (Spatial-α, -β and -γ highly expressed in the thymus and two long isoforms (Spatial-δ and -ε highly expressed in the testis. These alternative spliced variants could have a tissue specific function.

Radioimmunotoxicological effect of enriched uranium on central and peripheral immune cells and the protective action of IL-1 and IL-2

International Nuclear Information System (INIS)

Zhu Shoupeng; Lai Guanhua; Wang Liuyi

1993-01-01

With accumulation of enriched uranium 235 U-UO 2 F 2 in organism, it was found that enriched uranium had injurious effect on the immune function of central and peripheral immune cells. After intravenous injection of enriched uranium the spontaneous 3 H-TdR incorporation in thymocytes and bone marrow cells decreased. Though the sensitivity of immune cells to 235 U-UO 2 F 2 was different, the thymocytes were destroyed more markedly. Also the proliferation ability of T and B lymphocytes were both inhibited by enriched uranium 235 U. As compared with them, spleen B lymphocytes were inhibited more markedly than T lymphocytes. At the same time spleen lymphocytes IL-1 production and IL 2 consumption were diminished. It should be noted that the inhibition of spleen B lymphocytes proliferation by enriched uranium 235 U-UO 2 F 2 was partially restored by exogenous IL-1 or IL-2. The recovery rate of protective action at the very most was 67.1 +- 11.2% with exogenous IL-1 and 50.2 +- 8.0% with IL-2. Moreover, both exogenous IL-1 and IL-2 had synergetic effect, and the recovery rate was elevated to 83.1 +-12.3%

Intrathymic lymphopoiesis: stromal cell-associated proliferation of T cells is independent of lymphocyte genotype.

Science.gov (United States)

Kyewski, B A; Travis, M; Kaplan, H S

1984-09-01

We analyzed the genetic restriction of direct cell-cell interactions between thymocytes and a) cortical epithelial cells, b) macrophages, and c) medullary dendritic cells in the mouse thymus. Thymectomized (C3H X C57BL/Ka)F1 hybrid mice were doubly grafted with P1 and P2 neonatal thymus grafts, were lethally irradiated, and were reconstituted with a mixture of P1 and P2 bone marrow cells which differed in the Thy-1 locus. The contributions of both parental inocula to the composition of the free and stromal cell-associated T cell compartments were analyzed separately in thymic grafts of each parental strain. The lymphoid composition in both compartments essentially reflected the peripheral T cell-chimerism in the host. The development of lymphostromal complexes was not restricted by the genotype of the partner cells. Statistical analysis of the distributions of P1 and P2 T cells among free thymocytes and within individual lymphostromal complexes, however, suggests that the T cells of an individual complex are the progeny of oligoclonal proliferation. Thus, both epithelial cells and bone marrow-derived stromal cells seem to be involved in different stages of intrathymic lymphopoiesis.

Algunas figuras mitológicas en Quinto de Esmirna

Directory of Open Access Journals (Sweden)

Francisco Antonio García Romero

1989-06-01

Full Text Available Quintus has stressed the importance of certain divinities such as Eos, Horae, and Themis, which occupy a secondary place in Homer. This paper demonstrates the innovations made by the epic poet in certain aspects (genealogy, function, vocabulary and examines possible influences (several authors, notions of his age, etc. upon him.

Profound radiosensitivity in leukemic T-cell lines and T-cell-type acute lymphoblastic leukemia demonstrated by sodium [51Cr]chromate labeling

International Nuclear Information System (INIS)

Nakazawa, S.; Minowada, J.; Tsubota, T.; Sinks, L.F.

1978-01-01

Radiation sensitivity was determined by measuring spontaneous release from 51 Cr-labeled cells in various lymphoid cell populations. Among six leukemia T-cell lines originating from acute lymphoblastic leukemia, four such lines were found to be highly radiosensitive. In contrast, two of the leukemic T-cell lines and four normal control B-cell lines were not radiosensitive. Thymocytes from six patients and leukemia T-cell blasts from three patients with T-cell leukemia were likewise found to be highly radiosensitive, whereas leukemic blasts from six patients with null-cell (non-T, non-B-cell) acute lymphoblastic leukemia were not radiosensitive. Normal peripheral blood lymphocytes and mitogen-induced normal lymphoblasts were found not to be radiosensitive. The results indicate that measurement of the radiation sensitivity of acute leukemic blasts may have a therapeutic significance in coping with the heterogeneous nature of individual leukemia cases

The role of Protein Kinase Cη in T cell biology

Directory of Open Access Journals (Sweden)

Nicholas R.J. Gascoigne

2012-06-01

Full Text Available Protein kinase Cη (PKCη is a member of the novel PKC subfamily, which also includes δ, ε, and θ isoforms. Compared to the other novel PKCs, the function of PKCη in the immune system is largely unknown. Several studies have started to reveal the role of PKCη, particularly in T cells. PKCη is highly expressed in T cells, and is upregulated during thymocyte positive selection. Interestingly, like the θ isoform, PKCη is also recruited to the immunological synapse that is formed between a T cell and an antigen-presenting cell. However, unlike PKCθ, which becomes concentrated to the central region of the synapse, PKCη remains in a diffuse pattern over the whole area of the synapse, suggesting distinctive roles of these two isoforms in signal transduction. Although PKCη is dispensable for thymocyte development, further analysis of PKCη− or PKCθ−deficient and double knockout mice revealed the redundancy of these two isoforms in thymocyte development. In contrast, PKCη rather than PKCθ, plays an important role for T cell homeostatic proliferation, which requires recognition of self-antigen. Another piece of evidence demonstrating that PKCη and PKCθ have isoform specific as well as redundant roles come from the analysis of CD4 to CD8 T cell ratios in the periphery of these knockout mice. Deficiency in PKCη or PKCθ had opposing effects as PKCη knockout mice had a higher ratio of CD4 to CD8 T cells compared to that of wild-type mice, whereas PKCθ-deficient mice had a lower ratio. Biochemical studies showed that calcium flux and NFκB translocation is impaired in PKCη-deficient T cells upon TCR crosslinking stimulation, a character shared with PKCθ-deficient T cells. However, unlike the case with PKCθ, the mechanistic study of PKCη is at early stage and the signaling pathways involving PKCη, at least in T cells, are essentially unknown. In this review, we will cover the topics mentioned above as well as provide some

Copper-induced immunotoxicity involves cell cycle arrest and cell death in the spleen and thymus

International Nuclear Information System (INIS)

Mitra, Soham; Keswani, Tarun; Dey, Manali; Bhattacharya, Shaswati; Sarkar, Samrat; Goswami, Suranjana; Ghosh, Nabanita; Dutta, Anuradha; Bhattacharyya, Arindam

2012-01-01

Copper is an essential trace element for human physiological processes. To evaluate the potential adverse health impact/immunotoxicological effects of this metal in situ due to over exposure, Swiss albino mice were treated (via intraperitoneal injections) with copper (II) chloride (copper chloride) at doses of 0, 5, or 7.5 mg copper chloride/kg body weight (b.w.) twice a week for 4 wk; these values were derived from LD 50 studies using copper chloride doses that ranged from 0 to 40 mg/kg BW (2×/wk, for 4 wk). Copper treated mice evidenced immunotoxicity as indicated by dose-related decreases and increases, respectively, in thymic and splenic weights. Histomorphological changes evidenced in these organs were thymic atrophy, white pulp shrinkage in the spleen, and apoptosis of splenocytes and thymocytes; these observations were confirmed by microscopic analyses. Cell count analyses indicated that the proliferative functions of the splenocytes and thymocytes were also altered because of the copper exposures. Among both cell types from the copper treated hosts, flow cytometric analyses revealed a dose related increase in the percentages of cells in the Sub-G 0 /G 1 state, indicative of apoptosis which was further confirmed by Annexin V binding assay. In addition, the copper treatments altered the expression of selected cell death related genes such as EndoG and Bax in a dose related manner. Immunohistochemical analyses revealed that there was also increased ubiquitin expression in both the cell types. In conclusion, these studies show that sublethal exposure to copper (as copper chloride) induces toxicity in the thymus and spleen, and increased Sub G 0 /G 1 population among splenocytes and thymocytes that is mediated, in part, by the EndoG–Bax–ubiquitin pathway. This latter damage to these cells that reside in critical immune system organs are likely to be important contributing factors underlying the immunosuppression that has been documented by other

Old Geology and New Geology

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 28 May 2003Mangala Vallis one of the large outflow channels that channeled large quantities of water into the northern lowlands, long ago on geological timescales. This valley is one of the few in the southern hemisphere, as well as one of the few west of the Tharsis bulge. A closer look at the channel shows more recent weathering of the old water channel: the walls of the channel show small, dark slope streaks that form in dusty areas; and much of the surrounding terrain has subtle linear markings trending from the upper left to the lower right, which are probably features sculpted and streamlined by the wind. Geology still shapes the surface of Mars today, but its methods over the eons have changed.Image information: VIS instrument. Latitude -6, Longitude 209.6 East (150.4 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Aureum Chaos

Science.gov (United States)

2003-01-01

[figure removed for brevity, see original site] Released 11 November 2003Aureum Chaos is a large crater that was filled with sediment after its formation. After the infilling of sediment, something occurred that caused the sediment to be broken up into large, slumped blocks and smaller knobs. Currently, it is believed that the blocks and knobs form when material is removed from the subsurface, creating void space. Subsurface ice was probably heated, and the water burst out to the surface, maybe forming a temporary lake. Other areas of chaos terrain have large outflow channels that emanate from them, indicating that a tremendous amount of water was released.Image information: VIS instrument. Latitude -3.2, Longitude 331 East (29 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

Effects of Human Self-Assessment Responding on Learning

Science.gov (United States)

1980-08-01

short. - he who thinks himself worthy of great things, being unwort~hy of themi is vain. Aristotle, 4th century B.C. (translator W. D. Ross in Auden , 1970...No. 7, i: 493-499. Auden , W. H. (ed.). The Portable Greek Reader. Clinton, Mass.: The Colonial Press, 1970. Bandura, A. Self-efficacy: Toward a

Got Grit? Maybe…

Science.gov (United States)

Duckor, Brent

2017-01-01

The constructs that currently animate today's dispositions movement are grit and growth mindset. However, the evidence for the reliability and instructional uses of such noncognitive factors in K-12 schools--and of the surveys and tools that attempt to measure them--is thin. After a look at the "logic of assessment" with its focus on…

Kelvin-Helmholtz Instability: Lessons Learned and Ways Forward

Science.gov (United States)

Masson, A.; Nykyri, K.

2018-06-01

The Kelvin-Helmholtz instability (KHI) is a ubiquitous phenomenon across the Universe, observed from 500 m deep in the oceans on Earth to the Orion molecular cloud. Over the past two decades, several space missions have enabled a leap forward in our understanding of this phenomenon at the Earth's magnetopause. Key results obtained by these missions are first presented, with a special emphasis on Cluster and THEMIS. In particular, as an ideal instability, the KHI was not expected to produce mass transport. Simulations, later confirmed by spacecraft observations, indicate that plasma transport in Kelvin-Helmholtz (KH) vortices can arise during non-linear stage of its development via secondary process. In addition to plasma transport, spacecraft observations have revealed that KHI can also lead to significant ion heating due to enhanced ion-scale wave activity driven by the KHI. Finally, we describe what are the upcoming observational opportunities in 2018-2020, thanks to a unique constellation of multi-spacecraft missions including: MMS, Cluster, THEMIS, Van Allen Probes and Swarm.

How Near is a Near-Optimal Solution: Confidence Limits for the Global Optimum.

Science.gov (United States)

1980-05-01

TEXAS A&M UNIVERSITY COLlGE STATION, TEXAS 77843 T(kH,,JE MI S/ 80101 0 9 10 016 TEXAS A&M UNIVERSITY PROJECT THEMIS () -Technical eport6 o/ OW NEAR... physical characteristics of the problem. The collection gl, "’’ gL represents L nonrandom estimates of C Since they are nonrandom, the confidence

Relationship between Post-kidney Transplantation Antithymocyte Globulin Therapy and Wound Healing Complications

OpenAIRE

Pourmand, G. R.; Dehghani, S.; Saraji, A.; Khaki, S.; Mortazavi, S. H.; Mehrsai, A.; Sajadi, H.

2012-01-01

Background: Wound healing disorders are probably the most common post-transplantation surgical complications. It is thought that wound healing disturbance occurs due to antiproliferative effects of immunosuppressive drugs. On the other hand, success of transplantation is dependent on immunosuppressive therapies. Antihuman thymocyte globulin (ATG) has been widely used as induction therapy but the impact of this treatment on wound healing is not fully understood. Objective: To investigate wound...

Estimation of the parameters of cytotoxicity of fullerene C60 and C60-containing composites in vitro

International Nuclear Information System (INIS)

Priluts'ka, S.V.; Grinyuk, Yi.Yi.; Golub, O.A.; Matishevs'ka, O.P.

2006-01-01

The influence of fullerene C 60 and C 60 -containing composites (on the basis of aminopropylaerosyl (ApA)) on the stability of erythrocytes to acid haemolysis and the viability of thymocytes, ascite forms of Erlich and leucosis L1210 cells is studied. The obtained results indicate the possibility to use ApA as a matrix for conjugation with other elements and for the further biological studies of composites photosensitizing the effect

Changes in protein expression in p53 deleted spontaneous thymic lymphomas

DEFF Research Database (Denmark)

Honoré, Bent; Vorum, Henrik; Pedersen, Anders Elm

2004-01-01

with the protein expression in p53+/+ and p53-/- thymocytes. Only a minority (13 proteins) of the quantitatively changed proteins were common for the two thymic lymphoma cell lines, suggesting that the p53 deficiency mainly results in genetic dysfunctions which are individual for a given tumor. Two of the detected...... structure containing motifs of the glyoxalase-bleomycin resistance protein family (MDR) as deduced from the cDNA....

Prenatal cadmium exposure alters postnatal immune cell development and function

Energy Technology Data Exchange (ETDEWEB)

Hanson, Miranda L.; Holásková, Ida; Elliott, Meenal; Brundage, Kathleen M.; Schafer, Rosana; Barnett, John B., E-mail: jbarnett@hsc.wvu.edu

2012-06-01

Cadmium (Cd) is generally found in low concentrations in the environment due to its widespread and continual use, however, its concentration in some foods and cigarette smoke is high. Although evidence demonstrates that adult exposure to Cd causes changes in the immune system, there are limited reports of immunomodulatory effects of prenatal exposure to Cd. This study was designed to investigate the effects of prenatal exposure to Cd on the immune system of the offspring. Pregnant C57Bl/6 mice were exposed to an environmentally relevant dose of CdCl{sub 2} (10 ppm) and the effects on the immune system of the offspring were assessed at two time points following birth (2 and 7 weeks of age). Thymocyte and splenocyte phenotypes were analyzed by flow cytometry. Prenatal Cd exposure did not affect thymocyte populations at 2 and 7 weeks of age. In the spleen, the only significant effect on phenotype was a decrease in the number of macrophages in male offspring at both time points. Analysis of cytokine production by stimulated splenocytes demonstrated that prenatal Cd exposure decreased IL-2 and IL-4 production by cells from female offspring at 2 weeks of age. At 7 weeks of age, splenocyte IL-2 production was decreased in Cd-exposed males while IFN-γ production was decreased from both male and female Cd-exposed offspring. The ability of the Cd-exposed offspring to respond to immunization with a S. pneumoniae vaccine expressing T-dependent and T-independent streptococcal antigens showed marked increases in the levels of both T-dependent and T-independent serum antibody levels compared to control animals. CD4{sup +}FoxP3{sup +}CD25{sup +} (nTreg) cell percentages were increased in the spleen and thymus in all Cd-exposed offspring except in the female spleen where a decrease was seen. CD8{sup +}CD223{sup +} T cells were markedly decreased in the spleens in all offspring at 7 weeks of age. These findings suggest that even very low levels of Cd exposure during gestation can

Meridiani Crater in Day and Night

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 14 June 2004 This pair of images shows crater ejecta in the Terra Meridiani region. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude -1.6, Longitude 4.1 East (355.9 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in

Day And Night In Terra Meridiani

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 11 June 2004 This pair of images shows part of the Terra Meridiani region. Day/Night Infrared Pairs The image pairs presented focus on a single surface feature as seen in both the daytime and nighttime by the infrared THEMIS camera. The nighttime image (right) has been rotated 180 degrees to place north at the top. Infrared image interpretation Daytime: Infrared images taken during the daytime exhibit both the morphological and thermophysical properties of the surface of Mars. Morphologic details are visible due to the effect of sun-facing slopes receiving more energy than antisun-facing slopes. This creates a warm (bright) slope and cool (dark) slope appearance that mimics the light and shadows of a visible wavelength image. Thermophysical properties are seen in that dust heats up more quickly than rocks. Thus dusty areas are bright and rocky areas are dark. Nighttime: Infrared images taken during the nighttime exhibit only the thermophysical properties of the surface of Mars. The effect of sun-facing versus non-sun-facing energy dissipates quickly at night. Thermophysical effects dominate as different surfaces cool at different rates through the nighttime hours. Rocks cool slowly, and are therefore relatively bright at night (remember that rocks are dark during the day). Dust and other fine grained materials cool very quickly and are dark in nighttime infrared images. Image information: IR instrument. Latitude 1.3, Longitude 0.5 East (359.5 West). 100 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

Extra-adrenal glucocorticoid synthesis: immune regulation and aspects on local organ homeostasis.

Science.gov (United States)

Talabér, Gergely; Jondal, Mikael; Okret, Sam

2013-11-05

Systemic glucocorticoids (GCs) mainly originate from de novo synthesis in the adrenal cortex under the control of the hypothalamus-pituitary-adrenal (HPA)-axis. However, research during the last 1-2 decades has revealed that additional organs express the necessary enzymes and have the capacity for de novo synthesis of biologically active GCs. This includes the thymus, intestine, skin and the brain. Recent research has also revealed that locally synthesized GCs most likely act in a paracrine or autocrine manner and have significant physiological roles in local homeostasis, cell development and immune cell activation. In this review, we summarize the nature, regulation and known physiological roles of extra-adrenal GC synthesis. We specifically focus on the thymus in which GC production (by both developing thymocytes and epithelial cells) has a role in the maintenance of proper immunological function. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus.

Directory of Open Access Journals (Sweden)

Jie Dong

Full Text Available After a tightly regulated developmental program in the thymus, "mature" single positive (SP thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4(+ pre-RTEs, a population of CD4(+ SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4(+ pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs' better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4(+ pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4(+ pre-RTEs is independent of MHC class II and Aire molecules.

The immune system of geriatric mice is modulated by estrogenic endocrine disruptors (diethylstilbestrol, α-zearalanol, and genistein): Effects on interferon-γ

International Nuclear Information System (INIS)

Calemine, Jillian; Zalenka, Julie; Karpuzoglu-Sahin, Ebru; Ward, Daniel L.; Lengi, Andrea; Ahmed, S. Ansar

2003-01-01

The immune system is a potential target for estrogenic endocrine disrupters. To date, there is limited information on whether estrogenic endocrine disruptors modulate the immune system of aged individuals. To address this issue, groups of 74-week-old mice were given nine oral doses of selected estrogenic endocrine disrupters: diethylstilbestrol (DES, 3 μg/100 g bw), α-zearalanol (0.5 mg/100 g bw), or genistein (0.15 mg/100 g bw) in corn oil, or corn oil alone, over 2.5 weeks. Both developmental (thymus) and mature (spleen) lymphoid organs were affected, although specific effects varied with the chemical. DES significantly decreased thymocyte numbers. However, relative percentages of thymocyte subsets were not altered. While splenic cellularity and percentages of T and B cells were unchanged, splenocytes from DES-exposed mice had significantly decreased ability to proliferate in response to Concanavalin-A (Con-A). Con-A-activated splenocytes from mice treated with genistein or α-zearalanol had decreased levels of interferon-γ (IFNγ) protein in their culture supernatants compared to similar cultures from oil-treated mice. RT-PCR analysis of Con-A-activated splenocytes revealed that the expression of IFNγ gene is altered by DES or genistein treatment. Together, these results suggest that estrogenic endocrine disruptors modulate the immune system of aged mice

Dynamic changes of the early protein synthesis in murine immune cells after low dose radiation

International Nuclear Information System (INIS)

Chen Shali; Liu Shuzheng

1997-01-01

It was shown that there was a marked increase in protein synthesis of thymocytes that were metabolically labelled with 3 H-Leu for 4,6,8 and 12 hours in low dose irradiated mice showing 33.26%, 51.48%, 51.54% and 34.98% increase respectively at different time intervals of incubation when the thymic and splenic cells were sampled 4 hours after whole body irradiation (WBI) with 75 mGy X-rays. The results suggest that there is an increase in protein synthesis with its peak at 6∼8 hours after radiation. Changes in protein synthesis of immune cells in mice 4 hours after radiation and incubated for 4∼12 h were observed with SDS-PAGE followed by densitometrical scanning. It is revealed that 28 kD protein synthesis was increased gradually within 12 hours of incubation and 43 kD protein synthesis was increased in the thymocytes rapidly reaching a maximum 2 hours after incubation. It was also exhibited that the synthesis of 43 kD protein and 32 kD protein was increased in the splenocytes 2 hours after incubation. These findings may have implications in the mechanism of immunoenhancement and adaptive response induced by low dose radiation

Sedimentation of nucleoids from thymus and spleen cells of rats after X-irradiation in vitro and in vivo

International Nuclear Information System (INIS)

Heinzelmann, R.

1987-01-01

The reaction to irradiation of thymocytes was tested immediately and 6 hours after whole body X-irradiation of rats with doses from 190 cGy up to 1520 cGy by nucleoid sedimentation. For comparison, examinations of thymus and spleen cells after X-irradiation in vitro were done. Preliminary analyses should find a possible coergism between X-rays on one side and hyperthermia and inhibitors of DNA-synthesis or DNA-repair (cytosinearabinoside, dideoxythymidine, 3-amino-benzamide, ethidiumbromide, and novobiocine) on the other side. From the results the following conclusions may be drawn: 1) With respect to the detection of in vivo effects of X-irradiation, the nucleoid sedimentation is less sensitive than biochemical methods. 2) Some hours after sublethal X-irradiation in vivo, free DNA and/or polydesoxyribonucleotides appear. At the same time cross-links can be detected in the chromatin fraction. 3) The reduction of the nucleoid sedimentation immediately after high doses of whole-body irradiation is the result of primary DNA lesions. The changes detectable some hours after are due to the secondary enzymatic changes, that are connected with the interphase death of thymocytes, and coincide with the present opinions about the irradiation induced apoptosis of cells. (orig./ECB) [de

Leucocyte protein Trojan, a possible regulator of apoptosis.

Science.gov (United States)

Petrov, Petar; Syrjänen, Riikka; Uchida, Tatsuya; Vainio, Olli

2017-02-01

Trojan is a leucocyte-specific protein, cloned from chicken embryonic thymocyte cDNA library. The molecule is a type I transmembrane protein with an extracellular CCP domain, followed by two FN3 domains. Its cytoplasmic tail is predicted to possess a MAPK docking and a PKA phosphorylation sites. Trojan has been proposed to have an anti-apoptotic role based on its differential expression on developing thymocyte subpopulations. Using a chicken cell line, our in vitro studies showed that upon apoptosis induction, Trojan expression rises dramatically on the surface of surviving cells and gradually decreases towards its normal levels as cells recover. When sorted based on their expression levels of Trojan, cells with high expression appeared less susceptible to apoptotic induction than those bearing no or low levels of Trojan on their surface. The mechanism by which the molecule exerts its function is yet to be discovered. We found that cells overexpressing Trojan from a cDNA plasmid show elevated steady-state levels of intracellular calcium, suggesting the molecule is able to transmit cytoplasmic signals. The mechanistic nature of Trojan-induced signalling is a target of future investigation. In this article, we conducted a series of experiments that suggest Trojan as an anti-apoptotic regulator. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Thymectomized, irradiated, and bone marrow-reconstituted chimeras have normal cytolytic T lymphocyte precursors but a defect in lymphokine production

International Nuclear Information System (INIS)

Duprez, V.; Maziarz, R.; Weinberger, O.; Burakoff, S.J.

1984-01-01

A model system has been developed to study extrathymic T cell differentiation; mice have been thymectomized, lethally irradiated, and reconstituted with bone marrow cells depleted of Thy-1 + cells. After 8 wk, the spleen cells of these athymic, bone marrow-reconstituted chimeras contain Thy-1 + precytolytic T lymphocytes (CTL) that are able to respond to antigen only if supernatant from Con A-activated T cells is added to culture. The phenotype of these pre-CTL is similar to that of thymocytes, suggesting that they may be immature T cells. Initial evaluation of the CTL repertoire of these athymic mice demonstrated that the CTL generated to trinitrophenyl-modified syngeneic cells are H-2-restricted, and that the CTL generated to alloantigens have many of the cross-reactivities observed in normal mice but not in nude mice. In this report, the authors demonstrate a helper T cell defect in these thymectomized chimeras. These chimeras lack an Ly-1 + helper cell required for thymocytes to differentiate to CTL. Further studies revealed that when spleen cells from these thymectomized chimeras were stimulated with Con A, they produced normal levels of interleukin 2. However, these splenocytes were defective in the production of another factor needed for CTL differentiation

Graft-versus-host reaction and immune function. III. Functional pre-T cells in the bone marrow of graft-versus-host-reactive mice displaying T cell immunodeficiency

International Nuclear Information System (INIS)

Seddik, M.; Seemayer, T.A.; Lapp, W.S.

1986-01-01

Studies were performed to determine whether pre-T cells develop normally in the bone marrow of mice displaying thymic dysplasia and T cell immunodeficiency as a consequence of a graft-versus-host (GVH) reaction. GVH reactions were induced in CBAxAF1 mice by the injection of A strain lymphoid cells. To test for the presence of pre-T cells in GVH-reactive mice, bone marrow from GVH-reactive mice (GVHBM) was injected into irradiated syngeneic F1 mice and 30-40 days later thymic morphology and function were studied. Morphology studies showed nearly normal thymic architectural restoration; moreover, such glands contained normal numbers of Thy-1-positive cells. Functional pre-T cells were evaluated by transferring thymocytes from the irradiated GVHBM-reconstituted mice into T-cell-deprived mice. These thymocytes reconstituted allograft reactivity, T helper cell function and Con A and PHA mitogen responses of T-cell-deprived mice. These results suggest that the pre-T cell population in the bone marrow is not affected by the GVH reaction. Therefore, the T cell immunodeficiency associated with the GVH reaction is not due to a deficiency of pre-T cells in the bone marrow but is more likely associated with GVH-induced thymic dysplasia

Participation of lymphocytes in hemopoiesis regeneration under local irradiation of the body

International Nuclear Information System (INIS)

Gol'dberg, E.D.; Dygaj, A.M.

1982-01-01

Lymphocyte participation in regulation of a pool of stem blood-producing cells using a model of local irradiation of bone marrow was studied. Right pelvic limb of BALB/c strain mice was exposed to local X-radiation at a dose of 7.0 Gy. During different periods after the irradiation the animals were killed and the total number of nucleus-containing cells in thymus, spleen, bone marrow from irradiated and screened femurs were counted. Smears of bone marrow were used to calculate myelogram. To study thymocyte effect on postradiation regeneration of hemopoesis, each of thymectomized mice were injected intravenously 4x10 7 viable thymocytes. Processes of the postradiation regeneration of hemopoesis were specially investigated in animals against the background of intraperitoneal injection of antithymocytic heterologous serum. The population of stem blood-producing cells of bone marrow was studied by the method of exogenic cloning in the body of syngenic recipient lethally irradiated (7.5 Gy). It is shown that during the period before active recovery of hemopoesis observed is the selective accumulation of lymphocytes of predominantly thymus origin only in irradiated blood-producing tissue. T lymphocytes stimulated colony-forming activity of bone marrow and accelerated the postradiation regeneration of hemopoesis

Ultrastructural apoptotic lesions induced in rat thymocytes after borax ingestion.

Science.gov (United States)

Sylvain, I C; Berry, J P; Galle, P

1998-01-01

Apoptosis has gained increasing attention in recent years. Several chemical compounds induce apoptotic lesions in the thymus. Male Wistar rats received 2000 ppm of borax (Na2B4O7.10H2O) in their food for 16 days. The rats were sacrificed 2, 5, 9, 12, 19, 21, 26 and 28 days after the beginning of treatment. Thymus samples of all rats were taken. A Philips EM 300 electron microscopy was used to study the ultrastructural morphology. Serious nuclear and cytoplasmic lesions were observed. Moreover, numerous macrophages containing apoptotic cells were present in the thymus. The alterations were observed from the 2nd to the 28th day. The extent of damage was much more important in the rats sacrificed 21, 26 and 28 days after borax ingestion.

Thermophysical properties of the MER and Beagle II landing site regions on Mars

Science.gov (United States)

Jakosky, Bruce M.; Hynek, Brian M.; Pelkey, Shannon M.; Mellon, Michael T.; Martínez-Alonso, Sara; Putzig, Nathaniel E.; Murphy, Nate; Christensen, Philip R.

2006-08-01

We analyzed remote-sensing observations of the Isidis Basin, Gusev Crater, and Meridiani Planum landing sites for Beagle II, MER-A Spirit, and MER-B Opportunity spacecraft, respectively. We emphasized the thermophysical properties using daytime and nighttime radiance measurements from the Mars Global Surveyor (MGS) Thermal Emission Spectrometer and Mars Odyssey Thermal Emission Imaging System (THEMIS) and thermal inertias derived from nighttime data sets. THEMIS visible images, MGS Mars Orbiter Camera (MOC) narrow-angle images, and MGS Mars Orbiter Laser Altimeter (MOLA) data are incorporated as well. Additionally, the remote-sensing data were compared with ground-truth at the MER sites. The Isidis Basin surface layer has been shaped by aeolian processes and erosion by slope winds coming off of the southern highlands and funneling through notches between massifs. In the Gusev region, surface materials of contrasting thermophysical properties have been interpreted as rocks or bedrock, duricrust, and dust deposits; these are consistent with a complex geological history dominated by volcanic and aeolian processes. At Meridiani Planum the many layers having different thermophysical and erosional properties suggest periodic deposition of differing sedimentological facies possibly related to clast size, grain orientation and packing, or mineralogy.

Lymphocytes from wasted mice express enhanced spontaneous and {gamma}-ray-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Woloschak, G.E. [Argonne National Lab., IL (United States)]|[Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Chung, Jen; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1993-09-01

Mice bearing the autosomal recessive mutation wasted (wst/wst) display a disease pattern including faulty repair of DNA damage in lymphocytes after radiation exposure, neurologic abnormalities, and immunodeficiency. Many of the features of this mouse model have suggested a premature or increased spontaneous frequency of apoptosis in thymocytes; past work has shown an inability to establish cultured T cell lines, an abnormally high death rate of stimulated T cells in culture, and an increased sensitivity of T cells to the killing effects of ionizing radiations in wst/wst mice relative to controls. The experiments reported here were designed to examine splenic and thymic lymphocytes from wasted and control mice for signs of early apoptosis. Our results revealed enhanced expression of Rp-8 mRNA (associated with apoptosis) in thymic lymphocytes and reduced expression in splenic lymphocytes of wst/wst mice relative to controls; expression of Rp-2 and Td-30 mRNA (induced during apoptosis) were not detectable in spleen or thymus. Higher spontaneous DNA fragmentation was observed in wasted mice than in controls; however, {gamma}-ray-induced DNA fragmentation peaked at a lower dose and occurred to a greater extent in wasted mice relative to controls. These results provide evidence for high spontaneous and {gamma}-ray-induced apoptosis in T cells of wasted mice as a mechanism underlying the observed lymphocyte and DNA repair abnormalities.

Several Items Comparisons of Intercultural Food Communication

Institute of Scientific and Technical Information of China (English)

刘智慧

2011-01-01

Introduction This paper is included seven parts,food culture introduction,forms and manners of western food,forms and manners of Chinese food,three main kinds of difference of foods,mergence,taboo and conclusion.I will divide it into several parts to analyze them.I adopt ~me examples and history stories.As all of my expressions,I hope you can enjoy my paper and have a good stomach.

Opportunities for High-Power, High-Frequency Transmitters to Advance Ionospheric/Thermospheric Research: Report of a Workshop

Science.gov (United States)

2013-05-01

ground-based all-sky imagers that support the NASA THEMIS mission. Magnetometers at HAARP • Fluxgate magnetometer . This instrument is part of the...while others are owned by PI institutions and supported by the HAARP program. These diagnostic instruments include magnetometers , riometers, an...Ionosonde • HF/VHF Radars • Optical Photometer • Magnetometers ULF/ELF/VLF Receivers Striations Geomagnetic Field Artificial Ionized Layer Optical

Geologic Mapping of the Devana Chasma (V-29) Quadrangle, Venus

Science.gov (United States)

Tandberg, E. R.; Bleamaster, L. F., III

2010-01-01

The Devana Chasma quadrangle (V-29; 0-25degN/270-300degE) is situated over the northeastern apex of the Beta-Atla-Themis (BAT) province and includes the southern half of Beta Regio, the northern and transitional segments of the Devana Chasma complex, the northern reaches of Phoebe Regio, Hyndla Regio, and Nedolya Tesserae, and several smaller volcano-tectonic centers and impact craters.

First observation of rising-tone magnetosonic waves

Czech Academy of Sciences Publication Activity Database

Fu, H. S.; Cao, J. B.; Zhima, Z.; Khotyaintsev, Y. V.; Angelopoulos, V.; Santolík, Ondřej; Omura, Y.; Taubenschuss, U.; Chen, L.; Huang, S. Y.

2014-01-01

Roč. 41, č. 21 (2014), s. 7419-7426 ISSN 0094-8276 R&D Projects: GA MŠk 7E12026; GA MŠk(CZ) LH11122 Institutional support: RVO:68378289 Keywords : equatorial noise * ring distributions * cluster * propagation * emissions * region * themis * chorus Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 4.456, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2014GL061867/abstract

Comparing UV/EUV line parameters and magnetic field in a quiescent prominence with tornadoes

Science.gov (United States)

Levens, P. J.; Labrosse, N.; Schmieder, B.; López Ariste, A.; Fletcher, L.

2017-10-01

Context. Understanding the relationship between plasma and the magnetic field is important for describing and explaining the observed dynamics of solar prominences. Aims: We determine if a close relationship can be found between plasma and magnetic field parameters, measured at high resolution in a well-observed prominence. Methods: A prominence observed on 15 July 2014 by the Interface Region Imaging Spectrograph (IRIS), Hinode, the Solar Dynamics Observatory (SDO), and the Télescope Héliographique pour l'Étude du Magnétisme et des Instabilités Solaires (THEMIS) is selected. We perform a robust co-alignment of data sets using a 2D cross-correlation technique. Magnetic field parameters are derived from spectropolarimetric measurements of the He I D3 line from THEMIS. Line ratios and line-of-sight velocities from the Mg II h and k lines observed by IRIS are compared with magnetic field strength, inclination, and azimuth. Electron densities are calculated using Fe xii line ratios from the Hinode Extreme-ultraviolet Imaging Spectrometer, which are compared to THEMIS and IRIS data. Results: We find Mg II k/h ratios of around 1.4 everywhere, similar to values found previously in prominences. Also, the magnetic field is strongest ( 30 G) and predominantly horizontal in the tornado-like legs of the prominence. The k3 Doppler shift is found to be between ±10 km s-1 everywhere. Electron densities at a temperature of 1.5 × 106 K are found to be around 109 cm-3. No significant correlations are found between the magnetic field parameters and any of the other plasma parameters inferred from spectroscopy, which may be explained by the large differences in the temperatures of the lines used in this study. Conclusions: This is the first time that a detailed statistical study of plasma and magnetic field parameters has been performed at high spatial resolution in a prominence. Our results provide important constraints on future models of the plasma and magnetic field in

Terra Sirenum

Science.gov (United States)

2002-01-01

[figure removed for brevity, see original site] This image is from a region called Terra Sirenum in Mars' southern hemisphere. This region was named in 1958 for the Sea of the Sirens from Greek Mythology. This is not a sea, however, but a relatively dusty, high albedo region of Mars. There are numerous dust devil tracks that are apparent in the center- left of the image. The dust devils act like vacuum cleaners and lift dust off of the surface leaving a less dusty and relatively lower albedo surface behind. Dust devils are very common on Mars and are thought to be the primary mechanism for constantly lifting the dust into the atmosphere. Dust is constantly present in the Martian atmosphere in greater abundances than typically seen on Earth. The Martian dust is one of the main factors that affect the present Martian climate and clearly displays the relationship between Mars' geology and atmosphere.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of

Vortex, ULF wave and Aurora Observation after Solar Wind Dynamic Pressure Change

Science.gov (United States)

Shi, Q.

2017-12-01

Here we will summarize our recent study and show some new results on the Magnetosphere and Ionosphere Response to Dynamic Pressure Change/disturbances in the Solar Wind and foreshock regions. We study the step function type solar wind dynamic pressure change (increase/decrease) interaction with the magnetosphere using THEMIS satellites at both dayside and nightside in different geocentric distances. Vortices generated by the dynamic pressure change passing along the magnetopause are found and compared with model predictions. ULF waves and vortices are excited in the dayside and nightside plasma sheet when dynamic pressure change hit the magnetotail. The related ionospheric responses, such as aurora and TCVs, are also investigated. We compare Global MHD simulations with the observations. We will also show some new results that dayside magnetospheric FLRs might be caused by foreshock structures.Shi, Q. Q. et al. (2013), THEMIS observations of ULF wave excitation in the nightside plasma sheet during sudden impulse events, J. Geophys. Res. Space Physics, 118, doi:10.1029/2012JA017984. Shi, Q. Q. et al. (2014), Solar wind pressure pulse-driven magnetospheric vortices and their global consequences, J. Geophys. Res. Space Physics, 119, doi:10.1002/2013JA019551. Tian, A.M. et al.(2016), Dayside magnetospheric and ionospheric responses to solar wind pressure increase: Multispacecraft and ground observations, J. Geophys. Res., 121, doi:10.1002/2016JA022459. Shen, X.C. et al.(2015), Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: THEMIS observations, J. Geophys. Res., 120, doi:10.1002/2014JA020913Zhao, H. Y. et al. (2016), Magnetospheric vortices and their global effect after a solar wind dynamic pressure decrease, J. Geophys. Res. Space Physics, 121, doi:10.1002/2015JA021646. Shen, X. C., et al. (2017), Dayside magnetospheric ULF wave frequency modulated by a solar wind dynamic pressure negative impulse, J. Geophys. Res

The turmeric protective properties at ethanol-induced behavioral disorders.

Directory of Open Access Journals (Sweden)

Goldina I.A.

2017-03-01

Full Text Available The aim of the study was to determine the effect of mechanically modified turmeric extract on the parameters of orienting-exploratory behavior in mice with chronic ethanol consumption. Material and methods. Mice behavior was assessed in the "open field" test. In the both control groups the animals received water or 10% ethanol solution; in the test group — turmeric extract in 10% ethanol solution. Amount of blood mononuclear cells, thymocytes, and splenocytes were estimated. Results. Analysis of the behavioral parameters in animals after chronic exposure to ethanol showed suppression of motor and exploratory components of the behavior. In mice that received both ethanol and turmeric extract recorded behavior parameters were significantly higher than in the group of animals who received ethanol only. It was shown that the turmeric extract enhances the amount of blood immune cells. Conclusion. Mechanically modified turmeric extract possesses protective properties against ethanol-induced behavioral disorders.

Further studies on the H-2 linked dependence of the adjuvant action of Brucella abortus

International Nuclear Information System (INIS)

Oth, D.; Sabolovic, D.

1978-01-01

The B 19S strain of Brucella abortus has been found to act as an adjuvant to the anti-sheep red blood cell (SRBC) reaction in some congenic strains of mice but not in others. If the recipient was H-2sup(b), there was no adjuvant effect (B 19S); neither was there (thymus-dependent) anti-B 19S reaction as measured by thymocyte activation and change of electrophoretic mobility. In contrast, there was a thymus-independent anti-B 19S reaction (production of haemagglutinins) as good in the H-2sup(b) mice as in the others. Experiments with T cell deprived mice showed that the adjuvant action of B 19S was thymus-dependent. As the anti-SRBC reaction without adjuvant was also thymus-dependent, it was difficult to distinguish anti-SRBC and anti-B reactions from the adjuvant action of B 19S on the anti-SRBC reaction. Several explanations are possible, all involving H-2 (Isup(r)) controlled thymus dependent mechanisms. (author)

A Phosphosite within the SH2 Domain of Lck Regulates Its Activation by CD45.

Science.gov (United States)

Courtney, Adam H; Amacher, Jeanine F; Kadlecek, Theresa A; Mollenauer, Marianne N; Au-Yeung, Byron B; Kuriyan, John; Weiss, Arthur

2017-08-03

The Src Family kinase Lck sets a critical threshold for T cell activation because it phosphorylates the TCR complex and the Zap70 kinase. How a T cell controls the abundance of active Lck molecules remains poorly understood. We have identified an unappreciated role for a phosphosite, Y192, within the Lck SH2 domain that profoundly affects the amount of active Lck in cells. Notably, mutation of Y192 blocks critical TCR-proximal signaling events and impairs thymocyte development in retrogenic mice. We determined that these defects are caused by hyperphosphorylation of the inhibitory C-terminal tail of Lck. Our findings reveal that modification of Y192 inhibits the ability of CD45 to associate with Lck in cells and dephosphorylate the C-terminal tail of Lck, which prevents its adoption of an active open conformation. These results suggest a negative feedback loop that responds to signaling events that tune active Lck amounts and TCR sensitivity. Copyright © 2017 Elsevier Inc. All rights reserved.

A cytotoxic serine proteinase isolated from mouse submandibular gland.

Science.gov (United States)

Shimamura, T; Nagumo, N; Ikigai, H; Murakami, K; Okubo, S; Toda, M; Ohnishi, R; Tomita, M

1989-08-01

We have isolated a novel cytotoxic factor from the submandibular glands of male BALB/c mice by Sephadex G-50 gel filtration chromatography and reverse-phase HPLC. The cytotoxic factor is a serine proteinase, which belongs to the mouse glandular kallikrein (mGK) family, with an Mr of approximately 27,000. The purified serine proteinase showed cytotoxic activity against mouse thymocytes in a dose-dependent manner, and a serine proteinase inhibitor, diisopropyl fluorophosphate, blocked its cytotoxic activity.

Environmental tobacco smoke is just as damaging to DNA as mainstream smoke.

OpenAIRE

Bermúdez, E; Stone, K; Carter, K M; Pryor, W A

1994-01-01

This study demonstrates the ability of tar isolated from environmental tobacco smoke (ETS) to nick DNA in mammalian cells. Solutions of ETS tar behave similarly to aqueous solutions of cigarette tar from mainstream smoke. Both solutions contain the tar semiquinone radical, and this radical associates with the DNA in viable rat alveolar macrophages. Solutions of tar from ETS cause single-strand DNA breaks in rat thymocytes in proportion to the amount of tar present, until a plateau is reached....

B cells and B cell products-helping to restore cellular immunity?

OpenAIRE

Cascalho, Marilia; Platt, Jeffrey L.

2006-01-01

T cells that provide vital protection against tumors, viruses and intracellular bacteria are thought to develop independently of B cells. However, recent discoveries suggest that development of T cells depends on B cells. One way B cells promote T cell development is by providing diverse peptides that may promote positive selection of thymocytes. Diverse peptides and B cells help in diversification of the T cell receptor repertoire and may decrease cross-reactivity in the mature T cell compar...

Influence on the mouse immune system of chronic ingestion of 137Cs

International Nuclear Information System (INIS)

Bertho, Jean-Marc; Faure, Marie-Cecile; Louiba, Sonia; Tourlonias, Elie; Stefani, Johanna; Siffert, Baptiste; Paquet, Francois; Dublineau, Isabelle

2011-01-01

The aim of this work was to determine the possible occurrence of damage to the immune system during the course of chronic ingestion of 137 Cs. BALB/C mice were used, with 137 Cs intake via drinking water at a concentration of 20 kBq l -1 . Adults received 137 Cs before mating and offspring were sacrificed at various ages between birth and 20 weeks. Phenotypic analysis of circulating blood cells and thymocytes did not show any significant modification of immune cell populations in animals ingesting 137 Cs as compared with control animals, with the exception of a slight increase in Treg percentage at the age of 12 weeks. Functional tests, including proliferative response to mitogens such as phytohaemagglutinin, response to alloantigens in mixed lymphocyte reaction and immunoglobulin response to vaccine antigens such as tetanus toxin and keyhole limpet haemocyanin did not show any significant functional modification of the immune system in 137 Cs-ingesting animals as compared with control animals. Overall, our results suggest that chronic ingestion of a low concentration of 137 Cs in drinking water in the long term does not have any biologically relevant effect on the immune system.

Studies on the mechanism of the self restriction of T cell responses in radiation chimeras

International Nuclear Information System (INIS)

Fink, P.J.; Bevan, M.J.

1981-01-01

Recent experiments with murine radiation chimeras have shown that F 1 T cells that mature in an H-2 homozygous thymus, as is the case in [F 1 → Parent 1] chimeras, are restricted to recognizing foreign antigen in the context of Parent 1 H-2 antigens. Conflicting results on the stringency of self H-2 restriction of T cells from normal mice have suggested that the thymic restriction in chimeras may be due to active suppression of parent 2-restricted T cell clones. We have therefore conducted 3 sets of experiments to test for suppression of maturing T cells that could mediate thymic tutoring of H-2-restriction specificity in chimeras. In 2 sets of experiments, we found no evidence that suppressor cells could be exported from 1 thymus and act either intrathymically on thymocytes in a 2nd thymus or extrathymically on recent thymic emigrants. We believe current data support a role for the thymus in positive as well as negative selection of maturing thymocytes on the basis of self recognition, in the absence of any suppression. Our results do not support the concept that suppression is responsible for the difference in the degree of self preference in the T cells of chimeric mice relative to cell populations obtained from neonatally tolerant mice or from normal mice after acute negative selection

Peripheral subnuclear positioning suppresses Tcrb recombination and segregates Tcrb alleles from RAG2.

Science.gov (United States)

Chan, Elizabeth A W; Teng, Grace; Corbett, Elizabeth; Choudhury, Kingshuk Roy; Bassing, Craig H; Schatz, David G; Krangel, Michael S

2013-11-26

Allelic exclusion requires that the two alleles at antigen-receptor loci attempt to recombine variable (V), diversity (D), and joining (J) gene segments [V(D)J recombination] asynchronously in nuclei of developing lymphocytes. It previously was shown that T-cell receptor β (Tcrb) alleles frequently and stochastically associate with the nuclear lamina and pericentromeric heterochromatin in CD4(-)CD8(-) thymocytes. Moreover, rearranged alleles were underrepresented at these locations. Here we used 3D immunofluorescence in situ hybridization to identify recently rearranged Tcrb alleles based on the accumulation of the DNA-repair protein 53BP1. We found that Tcrb alleles recombine asynchronously in double-negative thymocytes and that V(D)J recombination is suppressed on peripheral as compared with central Tcrb alleles. Moreover, the recombination events that did take place at the nuclear periphery preferentially occurred on Tcrb alleles that were partially dissociated from the nuclear lamina. To understand better the mechanism by which V(D)J recombination is suppressed at the nuclear periphery, we evaluated the subnuclear distribution of recombination-activating gene 2 (RAG2) protein. We found that RAG2 abundance was reduced at the nuclear periphery. Moreover, RAG2 was distributed differently from RNA polymerase II and histone H3K4 trimethylation. Our data suggest that the nuclear periphery suppresses V(D)J recombination, at least in part, by segregating Tcrb alleles from RAG proteins.

Don't go with the Flow: An Invitation to Magnetosheath and Foreshock Studies

Science.gov (United States)

Sibeck, D. G.

2010-01-01

This talk reviews the predictions of gasdynamic, magnetohydrodynamic, and kinetic models for the magnetosheath and foreshock and compares these predictions with observations by the recent Cluster and THEMIS missions. Topics of interest include: the depletion layer, dawn/dusk asymmetries, the transmission of solar wind discontinuities, the formation of hot flow anomalies and cavities in the foreshock, and flows accelerated by field-line tension. We conclude by discussing opportunities for magnetosheath imaging.

Tissue specific distribution of iNKT cells impacts their cytokine response

OpenAIRE

Lee, You Jeong; Wang, Haiguang; Starrett, Gabriel J.; Phuong, Vanessa; Jameson, Stephen C.; Hogquist, Kristin A.

2015-01-01

Three subsets of invariant natural killer T (iNKT) cells have been identified, NKT1, NKT2 and NKT17, which produce distinct cytokines when stimulated, but little is known about their localization. Here, we have defined the anatomic localization and systemic distribution of these subsets and measured their cytokine production. Thymic NKT2 cells that produced interleukin-4 (IL-4) at steady state were located in the medulla and conditioned medullary thymocytes. NKT2 cells were abundant in the me...

Effects of insulin on the survival of irradiated chinese hamster lung cells

Energy Technology Data Exchange (ETDEWEB)

Lin, P S; Kwock, L; Hefter, K; Wallach, D F.H.; Brotman, R [Tufts-New England Medical Center, Boston, Mass. (USA)

1977-01-01

Insulin treatment (10/sup -7/-10/sup -9/ M) before ..gamma.. irradiation (50 to 500 rads) increases the long term survival of Chinese hamster lung cells (DON). Our data indicates that the radioprotective effect of insulin is not due to a modulation of cyclic-adenosine-3',5'-monophosphate levels within these cells. The results suggest that the radiosensitive plasma membrane component postulated to be involved in the interphase death of thymocytes and protected by insulin may have a counterpart in DON cells.

Recent successes and emerging challenges for coordinated satellite/ground-based magnetospheric exploration and modeling.

Science.gov (United States)

Angelopoulos, Vassilis

With the availability of a distributed constellation of spacecraft (THEMIS, Geotail, Cluster) and increased capability ground based arrays (SuperDARN, THEMIS/GBOs), it is now pos-sible to infer simply from timing significant information regarding mapping of magnetospheric phenomena. Optical, magnetometer and radar data can pinpoint the location and nature of onset signatures. On the other hand, magnetic field modeling constrained by physical bound-aries (such as the isotropy boundary) the measured magnetic field and total pressure values at a distibuted network of satellites has proven to do a much better job at correlating ionospheric precipitation and diffuse auroral boundaries to magnetospheric phenomena, such as the inward boundary of the dipolarization fronts. It is now possible to routinely compare in-situ measured phase space densities of ion and electron distributions during ionosphere -magnetosphere con-junctions, in the absense of potential drops. It is also possible to not only infer equivalent current systems from the ground, but use reconstruction of the ionospheric current system from space to determine the full electrodynamics evolution of the ionosphere and compare with radars. Assimilation of this emerging ground based and global magnetospheric panoply into a self consistent magnetospheric model will likely be one of the most fruitful endeavors in magnetospheric exploration during the next few years.

Mission Oriented Support and Theory (MOST) for MMS -- The Goddard Space Flight Center/University of California Los Angeles Interdisciplinary Science Program

Science.gov (United States)

Goldstein, Melvyn L.; Ashour-Abdalla, Maha; F. Vinas, Adolfo; Dorelli, John; Wendel, Deirdre; Klimas, Alex; Hwang, Kyoung-Joo; El-Alaoui, Mostafa; Walker, Raymond J.; Pan, Qingjiang;

The water content of recurring slope lineae on Mars

Science.gov (United States)

Edwards, Christopher S.; Piqueux, Sylvain

2016-01-01

Observations of recurring slope lineae (RSL) from the High-Resolution Imaging Science Experiment have been interpreted as present-day, seasonally variable liquid water flows; however, orbital spectroscopy has not confirmed the presence of liquid H2O, only hydrated salts. Thermal Emission Imaging System (THEMIS) temperature data and a numerical heat transfer model definitively constrain the amount of water associated with RSL. Surface temperature differences between RSL-bearing and dry RSL-free terrains are consistent with no water associated with RSL and, based on measurement uncertainties, limit the water content of RSL to at most 0.5–3 wt %. In addition, distinct high thermal inertia regolith signatures expected with crust-forming evaporitic salt deposits from cyclical briny water flows are not observed, indicating low water salinity (if any) and/or low enough volumes to prevent their formation. Alternatively, observed salts may be preexisting in soils at low abundances (i.e., near or below detection limits) and largely immobile. These RSL-rich surfaces experience ~100 K diurnal temperature oscillations, possible freeze/thaw cycles and/or complete evaporation on time scales that challenge their habitability potential. The unique surface temperature measurements provided by THEMIS are consistent with a dry RSL hypothesis or at least significantly limit the water content of Martian RSL.

Traveling foreshocks and transient foreshock phenomena

OpenAIRE

Kajdič, P.; Blanco-Cano, X.; Omidi, N.; Rojas-Castillo, D.; Sibeck, D.G.; Billingham, L.

2017-01-01

We use the multispacecraft capabilities of the Cluster and Time History of Events and Macroscale Interactions during Substorms (THEMIS) missions to show that two types of foreshock may be detected in spacecraft data. One is the global foreshock that appears upstream of the Earth's quasi-parallel bow shock under steady or variable interplanetary magnetic field. Another type is a traveling foreshock that is bounded by two rotational discontinuities in the interplanetary magnetic field and propa...

Sensitivity of T-Lymphocytes to Hormones of the Anterior Pituitary Gland.

Science.gov (United States)

Tishevskaya, N V; Gevorkyan, N M; Kozlova, N I

2017-01-01

The review provides information about the features of the sensitivity of thymocytes, lymphoid organs' cells and T-lymphocytes of peripheral blood to the hormones secreted by anterior pituitary gland's cells: growth hormone, thyrotropin, adrenocorticotropic hormone, prolactin and β-endorphin. Some aspects of the T-lymphocytes's response to humoral signals from the hypophysis are shown in the article. Also the pituitary hormones' role in the regulation of proliferation, differentiation, and cytokine production of T-lymphocytes in normal and pathological conditions of the organism being discussed.

Time-effect relationship of immunological adaptive response induced by low dose X-irradiation in mice

International Nuclear Information System (INIS)

Zhao Yong; Gong Shouliang; Liu Shuzheng

1995-01-01

Kunming mice irradiated with whole-body X-rays were used to observe time-effect relationship of immunological adaptive response induced by ionizing radiation. The results showed that pre-irradiation dose of 75 mGy X-rays with the intervals of 6-48 h between pre-irradiation and challenge irradiation could induce immunological adaptive response in the spontaneous proliferation of thymocytes and the responses of splenocytes to Con A and LPS in mice at 18-24 h after challenge irradiation with 1.5-2.0 Gy X-rays

Syngeneic transplantation in aplastic anemia

DEFF Research Database (Denmark)

Gerull, Sabine; Stern, Martin; Apperley, Jane

2013-01-01

Aplastic anemia is usually treated with immunosuppression or allogeneic transplant, depending on patient and disease characteristics. Syngeneic transplant offers a rare treatment opportunity with minimal transplant-related mortality, and offers an insight into disease mechanisms. We present here...... a retrospective analysis of all syngeneic transplants for aplastic anemia reported to the European Group for Blood and Marrow Transplantation. Between 1976 and 2009, 88 patients received 113 transplants. Most transplants (n=85) were preceded by a conditioning regimen, 22 of these including anti-thymocyte globulin...

MHC class II polymorphisms, autoreactive T-cells and autoimmunity

Directory of Open Access Journals (Sweden)

Sue eTsai

2013-10-01

Full Text Available Major histocompatibility complex (MHC genes, also known as human leukocyte antigen genes (HLA in humans, are the prevailing contributors of genetic susceptibility to autoimmune diseases such as Type 1 Diabetes (T1D, Multiple Sclerosis (MS, and Rheumatoid arthritis (RA, among others (Todd and Wicker, 2001;MacKay et al., 2002;Hafler et al., 2007. Although the pathways through which MHC molecules afford autoimmune risk or resistance remain to be fully mapped out, it is generally accepted that they do so by shaping the central and peripheral T cell repertoires of the host towards autoimmune proclivity or resistance, respectively. Disease-predisposing MHC alleles would both spare autoreactive thymocytes from central tolerance and bias their development towards a pathogenic phenotype. Protective MHC alleles, on the other hand, would promote central deletion of autoreactive thymocytes and skew their development towards non-pathogenic phenotypes. This interpretation of the data is at odds with two other observations: that in MHC-heterozygous individuals, resistance is dominant over susceptibility; and that it is difficult to understand how deletion of one or a few clonal autoreactive T cell types would suffice to curb autoimmune responses driven by hundreds if not thousands of autoreactive T cell specificities. This review provides an update on current advances in our understanding of the mechanisms underlying MHC class II-associated autoimmune disease susceptibility and/or resistance and attempts to reconcile these seemingly opposing concepts.

Opioid modulation of immunocompetence: Receptor characterization and second messenger involvement

International Nuclear Information System (INIS)

Hemmick, L.M.

1989-01-01

The purpose of this thesis was to examine the effects of opioids on several indices of immunocompetence, determined the receptor specificity of these effects, and ascertain whether the actions of opioids on lymphocytes could be correlated with activation of second messenger systems. By measuring 45 Ca 2+ uptake into lymphocytes, it was demonstrated that β-endorphin 1-31 (β-END 1-31) enhanced rat thymocyte Ca 2+ uptake in response to concanavalin A (Con A) but not phytohemagglutinin (PHA). Related opioid peptides and alkaloids were unable to mimic the effect, and naloxone did not block it, suggesting that β-END 1-31 acted by binding to specific, non-opioid receptors on the thymocytes. Rat splenocyte Con A-stimulated Ca 2+ uptake was not affected by β-END 1-31. β-END 1-31 did not affect basal Ca 2+ uptake by either cell type. Using [ 3 H]thymidine uptake as an index of lymphocyte proliferation, β-END 1-31 and several related opioid peptides reversed prostaglandin E 1 (PGE 1 ) suppression of rat lymph node cell Con A- and PHA-stimulated proliferation. Naloxone did not block the reversal. β-END 1-31 was unable to reverse forskolin and cholera toxin suppression of proliferation, indicating that the lowering of cyclic AMP levels was not the mechanism involved. Verapamil inhibition of proliferation was also not reversed by β-END 1-31, suggesting that promotion of Ca 2+ influx was not a major mechanism involved

Mismatch repair deficient hematopoietic stem cells are preleukemic stem cells.

Directory of Open Access Journals (Sweden)

Yulan Qing

Full Text Available Whereas transformation events in hematopoietic malignancies may occur at different developmental stages, the initial mutation originates in hematopoietic stem cells (HSCs, creating a preleukemic stem cell (PLSC. Subsequent mutations at either stem cell or progenitor cell levels transform the PLSC into lymphoma/leukemia initiating cells (LIC. Thymic lymphomas have been thought to develop from developing thymocytes. T cell progenitors are generated from HSCs in the bone marrow (BM, but maturation and proliferation of T cells as well as T-lymphomagenesis depends on both regulatory mechanisms and microenvironment within the thymus. We studied PLSC linked to thymic lymphomas. In this study, we use MSH2-/- mice as a model to investigate the existence of PLSC and the evolution of PLSC to LIC. Following BM transplantation, we found that MSH2-/- BM cells from young mice are able to fully reconstitute multiple hematopoietic lineages of lethally irradiated wild-type recipients. However, all recipients developed thymic lymphomas within three and four months post transplantation. Transplantation of different fractions of BM cells or thymocytes from young health MSH2-/- mice showed that an HSC enriched fraction always reconstituted hematopoiesis followed by lymphoma development. In addition, lymphomas did not occur in thymectomized recipients of MSH2-/- BM. These results suggest that HSCs with DNA repair defects such as MSH2-/- are PLSCs because they retain hematopoietic function, but also carry an obligate lymphomagenic potential within their T-cell progeny that is dependent on the thymic microenvironment.

Molecular Mechanisms of Particle Ration Induced Apoptosis in Lymphocyte

Science.gov (United States)

Shi, Yufang

Space radiation, composed of high-energy charged nuclei (HZE particles) and protons, has been previously shown to severely impact immune homeostasis in mice. To determine the molecular mechanisms that mediate acute lymphocyte depletion following exposure to HZE particle radiation mice were exposed to particle radiation beams at Brookhaven National Laboratory. We found that mice given whole body 5 6Fe particle irradiation (1GeV /n) had dose-dependent losses in total lymphocyte numbers in the spleen and thymus (using 200, 100 and 50 cGy), with thymocytes being more sensitive than splenocytes. All phenotypic subsets were reduced in number. In general, T cells and B cells were equally sensitive, while CD8+ T cells were more senstive than CD4+ T cells. In the thymus, immature CD4+CD8+ double-positive thymocytes were exquisitely sensitive to radiation-induced losses, single-positive CD4 or CD8 cells were less sensitive, and the least mature double negative cells were resistant. Irradiation of mice deficient in genes encoding essential apoptosis-inducing proteins revealed that the mechanism of lymphocyte depletion is independent of Fas ligand and TRAIL (TNF-ralated apoptosis-inducing ligand), in contrast to γ-radiation-induced lymphocyte losses which require the Fas-FasL pathway. Using inhibitors in vitro, lymphocyte apoptosis induced by HZE particle radiation was found to be caspase dependent, and not involve nitric oxide or oxygen free radicals.

Effects of marrow grafting on preleukemia cells and thymic nurse cells in C57BL/Ka mice after a leukemogenic split-dose irradiation

International Nuclear Information System (INIS)

Defresne, M.P.; Greimers, R.; Lenaerts, P.; Boniver, J.

1986-01-01

A split-dose regimen of whole-body irradiation (4 X 175 rad at weekly intervals) induced thymic lymphomas in C57BL/Ka mice after a latent period of 3-9 months. Meanwhile, preleukemia cells arose in the thymus and bone marrow and persisted until the onset of lymphomas. Simultaneously, thymic lymphopoiesis was impaired; thymocyte numbers were subnormal and thymic nurse cells disappeared in a progressive but irreversible fashion. The depletion of these lymphoepithelial complexes, which are normally involved in the early steps of thymic lymphopoiesis, was related to altered prothymocyte activity in bone marrow and to damaged thymic microenvironment, perhaps as a consequence of the presence of preleukemia cells. The grafting of normal bone marrow cells after irradiation prevented the development of lymphomas. However, marrow reconstitution did not inhibit the induction of preleukemia cells. They disappeared from the thymus during the second part of the latent period. At the same time, thymic lymphopoiesis was restored; thymocytes and nurse cell numbers returned to normal as a consequence of the proliferation of grafted marrow-derived cells within the thymus. The results thus demonstrated an intimate relationship between preleukemia cells and an alteration of thymic lymphopoiesis, which particularly involved the nurse cell microenvironment. Some preleukemia cells in marrow-reconstituted, irradiated mice derived from the unirradiated marrow inoculate. Thus these cells acquired neoplastic potential through a factor present in the irradiated tissues. The nature of this indirect mechanism was briefly discussed

Carbon black nanoparticle exposure during middle and late fetal development induces immune activation in male offspring mice

International Nuclear Information System (INIS)

El-Sayed, Yasser S.; Shimizu, Ryuhei; Onoda, Atsuto; Takeda, Ken; Umezawa, Masakazu

2015-01-01

Increasing exposure to nanoparticles (NPs) has raised concerns regarding their health and safety profiles in humans and animals, especially in developing organisms, which may display increased sensitivity to NP toxicity. The present study examined the effects of gestational exposure to carbon black NP (CB-NP) on the development of the offspring immune system. Pregnant mice were exposed to CB-NP (95 μg/kg body weight) by intranasal instillation on gestational days 9 and 15. The thymus and spleen were collected from their offspring mice on postnatal day (PND) 1, 3 and 5. Thymocyte and splenocyte phenotypes were examined by determining the expression of cell-surface molecules using flow cytometry. Gene expression in the thymus and spleen was examined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Prenatal exposure to CB-NP increased total thymocytes and their immunophenotypes (CD4 − CD8 − and CD4 + CD8 + cells). It also induced an increase in total lymphocytes, and CD4 − CD8 − , particularly CD3 − B220 − cells, at PND 5 in the spleen of newborn male offspring, reflecting the stimulation of immature splenocytes. Furthermore, mRNA expression of genes related to the induction of peripheral tolerance (i.e. thymic Traf6) was upregulated. These data suggest that respiratory exposure to CB-NP during middle and late gestation may have allergic or inflammatory effects in male offspring, and may provide initial information on the potential developmental immunotoxicity of nanoparticles

Visualization of the human CD4+ T-cell response in humanized HLA-DR4-expressing NOD/Shi-scid/γcnull (NOG) mice by retrogenic expression of the human TCR gene

International Nuclear Information System (INIS)

Takahashi, Takeshi; Katano, Ikumi; Ito, Ryoji; Ito, Mamoru

2015-01-01

Highlights: • β-Lactoglobulin (BLG) specific TCR genes were introduced to human HSC by retrovirus. • Human HSC with BLG-specific TCR were transplanted into NOG-HLA-DR4 I-A −/− mice. • BLG-specific TCR induced positive selection of thymocytes. • BLG-specific TCR positive CD4 + T cells mediated immune responses in humanized mice. - Abstract: The development of severe immunodeficient mouse strains containing various human genes, including cytokines or HLA, has enabled the reconstitution of functional human immune systems after transplantation of human hematopoietic stem cells (HSC). Accumulating evidence has suggested that HLA-restricted antigen-specific human T-cell responses can be generated in these humanized mice. To directly monitor immune responses of human CD4 + T cells, we introduced β-lactoglobulin (BLG)-specific T cell receptor (TCR) genes derived from CD4 + T-cell clones of cow-milk allergy patients into HSCs, and subsequently transplanted them into NOG-HLA-DR4 transgenic/I-Aβ deficient mice (NOG-DR4/I-A o ). In the thymus, thymocytes with BLG-specific TCR preferentially differentiated into CD4 + CD8 − single-positive cells. Adoptive transfer of mature CD4 + T cells expressing the TCR into recipient NOG-DR4/I-A o mice demonstrated that human CD4 + T cells proliferated in response to antigenic stimulation and produced IFN-γ in vivo, suggesting that functional T-cell reactions (especially Th1-skewed responses) were induced in humanized mice

Rag defects and thymic stroma: lessons from animal models

Directory of Open Access Journals (Sweden)

Veronica eMarrella

2014-06-01

Full Text Available Thymocytes and thymic epithelial cells (TECs cross-talk is essential to support T-cell development and preserve thymic architecture and maturation of TECs and Foxp3+ natural regulatory T (nTreg cells. Accordingly, disruption of thymic lymphostromal cross-talk may have major implications on the thymic mechanisms that govern T cell tolerance. Several genetic defects have been described in humans that affect early stages of T cell development (leading to Severe Combined Immune Deficiency, SCID or late stages in thymocyte maturation (resulting in combined immunodeficiency. Hypomorphic mutations in SCID-causing genes may allow for generation of a limited pool of T lymphocytes with a restricted repertoire. These conditions are often associated with infiltration of peripheral tissues by activated T cells and immune dysregulation, as best exemplified by Omenn syndrome (OS. In this review, we will discuss our recent findings on abnormalities of thymic microenvironment in OS with a special focus of defective maturation of TECs, altered distribution of thymic dendritic cells (DCs and impairment of deletional and non-deletional mechanisms of central tolerance. Here, taking advantage of mouse models of OS and atypical SCID, we will discuss how modifications in stromal compartment impact and shape lymphocyte differentiation, and vice versa how inefficient T cell signalling results in defective stromal maturation. These findings are instrumental to understand the extent to which novel therapeutic strategies should act on thymic stroma to achieve full immune reconstitution.

Possible sea sediments due to glaciofluvial activity in Elysium Planitia, Mars

Science.gov (United States)

Nussbaumer, J.

Observations of fluvial morphologies in southern Elysium Planitia strongly supports the hypothesis that water substantially affected this region during the relatively recent geologic past. As of yet, however, the extent of a standing body of water has been speculative. The observation of zig-zag features potentially analogous to those observed near the Wadden Sea on Earth [see 1] may help show in more detail the origin, activity, and fate of water in this region of Mars. These terrestrial analogs could constrain environmental scenarios concerning the formation of these features. We present a geomorphologic map of central Elysium Planitia, that aids in our interpretation of potentially site-specific depositional/erosional morphologies. Positive relief zig-zag features within the Medusae Fossae Formation (Themis Image V05875001) resemble similar structures on Earth observed at shorelines of flat regions. Glaciofluvial activity is indicated by linear features resembling straight glacial flutings, which could form aeolian yardangs subsequently. The flutings are associated with branches of inverted fluvial channels (Images Themis V05588002, MOC e1800307). Their excavated positive relief (height ~40 m) indicates, that the adjacent material was eroded by sublimation or aeolian activity. The channels possibly resemble ice marginal channels. A high resolution Digital Terrain Model of one of the channels suggests, that one channel is possibly running upslope. Fluvial processes could have operated at one location at one time, and glacial processes at another location at another time [2]. A glacial drainage system [see 3] is a possible terrestrial analog for one inverted fluvial channel on Mars (Themis Image V05875001). Flutings occur on the foreland of many glaciers and their length may provide important evidence for rapid advance over substantial distances. Flutings are the product of subglacial erosion and transport processes [4]. By assigning the different environmental

Occurrence and Detectability of Thermal Anomalies on Europa

Science.gov (United States)

Hayne, Paul O.; Christensen, Philip R.; Spencer, John R.; Abramov, Oleg; Howett, Carly; Mellon, Michael; Nimmo, Francis; Piqueux, Sylvain; Rathbun, Julie A.

2017-10-01

Endogenic activity is likely on Europa, given its young surface age of and ongoing tidal heating by Jupiter. Temperature is a fundamental signature of activity, as witnessed on Enceladus, where plumes emanate from vents with strongly elevated temperatures. Recent observations suggest the presence of similar water plumes at Europa. Even if plumes are uncommon, resurfacing may produce elevated surface temperatures, perhaps due to near-surface liquid water. Detecting endogenic activity on Europa is one of the primary mission objectives of NASA’s planned Europa Clipper flyby mission.Here, we use a probabilistic model to assess the likelihood of detectable thermal anomalies on the surface of Europa. The Europa Thermal Emission Imaging System (E-THEMIS) investigation is designed to characterize Europa’s thermal behavior and identify any thermal anomalies due to recent or ongoing activity. We define “detectability” on the basis of expected E-THEMIS measurements, which include multi-spectral infrared emission, both day and night.Thermal anomalies on Europa may take a variety of forms, depending on the resurfacing style, frequency, and duration of events: 1) subsurface melting due to hot spots, 2) shear heating on faults, and 3) eruptions of liquid water or warm ice on the surface. We use numerical and analytical models to estimate temperatures for these features. Once activity ceases, lifetimes of thermal anomalies are estimated to be 100 - 1000 yr. On average, Europa’s 10 - 100 Myr surface age implies a resurfacing rate of ~3 - 30 km2/yr. The typical size of resurfacing features determines their frequency of occurrence. For example, if ~100 km2 chaos features dominate recent resurfacing, we expect one event every few years to decades. Smaller features, such as double-ridges, may be active much more frequently. We model each feature type as a statistically independent event, with probabilities weighted by their observed coverage of Europa’s surface. Our results

North Polar Cap

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour. In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime. The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap. Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen

Influence of some radioprotective and radiosensitizing compounds on the replicative and repair induced DNA synthesis of rats spleen cells in vitro

International Nuclear Information System (INIS)

Goette, A.

1982-01-01

The effect of cysteine, dithiothreitol, N-ethylmaleimide, cytosinearabinoside, ethidiumbromide, bleomycine and diethyldithiocarbamate on the replicative and repair induced DNA synthesis in vitro was tested by using rats spleen cells. Besides the incorporation of a labeled DNA precursor (TdR- 3 H) the sedimentation of DNA in sucrose gradients was inquired. With respect to the DNA synthesis an uniform mechanism of action for the radioprotective substances can't be seen. Thymocytes and spleen cells seem to possess different systems of repair; this may be an explanation for their different sensibility against ionizing radiation. (orig./MG) [de

Distribution of nuclease attack sites and complexity of DNA in the products of post-irradiation degradiation of rat thymus chromatin

International Nuclear Information System (INIS)

Zvonareva, N.B.; Zhivotovsky, B.D.; Hanson, K.P.

1983-01-01

The distribution of nuclease attack sites in chromatin has been studied on the basis of the quantitative relationship of the single- and double-stranded fragments of various lengths in the products of post-irradiation degradation of chromatin (PDN). It has been shown that in irradiated thymocytes internucleosome degradation of chromatin occurs and the products of the enzymic digestion of chromatin derive from randomly distributed genome areas accumulate. Analysis of the reassociation curves has not shown any differences in the complexity of the PDN fractions and total DNA. (author)

Human CD4 restores normal T cell development and function in mice deficient in murine CD4

OpenAIRE

1994-01-01

The ability of a human coreceptor to function in mice was investigated by generating human CD4 (hCD4)-expressing transgenic mice on a mouse CD4-deficient (mCD4-/-) background. From developing thymocyte to matured T lymphocyte functions, hCD4 was shown to be physiologically active. By examining the expansion and deletion of specific V beta T cell families in mutated mice with and without hCD4, it was found that hCD4 can participate in positive and negative selection. Mature hCD4 single positiv...

Effect of histones on hematopoietic stem cells-precursor in normal and irradiated organism

International Nuclear Information System (INIS)

Semina, O.V.; Semenets, T.N.; Zeppezauer, M.; Cebecauer, L.; Poverenny, A.M.

1994-01-01

Radiotherapeutic activity of histone fractions H 1 and H 2A /H 2B were studied. It was demonstrated that both fractions are able to reduce the damaging effect of ionizing radiation on spleen colony forming unit (CFU-S) population. Histone preparations stimulated colony-forming activity of bone marrow cells exposed to dose of 0.5-3.0 Gy both in the case of incubation with preparations and intravenous or intraperitoneal administration into recipients of irradiated cells. The effect of histones and accessory thymocytes on CFU-S population is compared

Pectic polysaccharide from the green fruits of Momordica charantia (Karela): structural characterization and study of immunoenhancing and antioxidant properties.

Science.gov (United States)

Panda, Bibhash C; Mondal, Soumitra; Devi, K Sanjana P; Maiti, Tapas K; Khatua, Somanjana; Acharya, Krishnendu; Islam, Syed S

2015-01-12

A water soluble pectic polysaccharide (PS) isolated from the aqueous extract of the green fruits of Momordica charantia contains D-galactose and D-methyl galacturonate in a molar ratio of nearly 1:4. It showed splenocyte, thymocyte as well as macrophage activations. Moreover, it exhibited potent antioxidant activities. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, and 1D and 2D NMR studies, the structure of the repeating unit of the pectic polysaccharide was established as: [Formula: see text]. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structural analyses and immunomodulatory properties of fructo-oligosaccharides from onion (Allium cepa).

Science.gov (United States)

Kumar, V Prasanna; Prashanth, K V Harish; Venkatesh, Y P

2015-03-06

Onion (Allium cepa) is an immune-boosting food rich in fructans. The major aim of this study is to characterize and investigate the immunomodulatory properties of onion fructo-oligosaccharides (FOS). FOS was isolated from onion bulbs by hot 80% ethanol extraction (yield: ∼4.5 g/100 g fw) followed by gel permeation chromatography. NMR of onion FOS revealed unusual β-D-Glc terminal residue at the non-reducing end. TLC and ESI-MS analyses showed that onion FOS ranged from trisaccharides to hexasaccharides. Onion FOS (50 μg/mL) significantly increased (∼3-fold) the proliferation of mouse splenocytes/thymocytes vs. control. Further, onion FOS enhanced (∼2.5-fold) the production of nitric oxide by peritoneal exudates cells (PECs) from Wistar rats; intracellular free radicals production and phagocytic activity of isolated murine PECs were also augmented. Our structural and in vitro results indicate that onion FOS comprising of tri- to hexasaccharide units belongs to inulin-type fructans, and possess immunostimulatory activities towards murine lymphocytes and macrophages. Copyright © 2014 Elsevier Ltd. All rights reserved.

Administration of RANKL boosts thymic regeneration upon bone marrow transplantation.

Science.gov (United States)

Lopes, Noella; Vachon, Hortense; Marie, Julien; Irla, Magali

2017-06-01

Cytoablative treatments lead to severe damages on thymic epithelial cells (TECs), which result in delayed de novo thymopoiesis and a prolonged period of T-cell immunodeficiency. Understanding the mechanisms that govern thymic regeneration is of paramount interest for the recovery of a functional immune system notably after bone marrow transplantation (BMT). Here, we show that RANK ligand (RANKL) is upregulated in CD4 + thymocytes and lymphoid tissue inducer (LTi) cells during the early phase of thymic regeneration. Importantly, whereas RANKL neutralization alters TEC recovery after irradiation, ex vivo RANKL administration during BMT boosts the regeneration of TEC subsets including thymic epithelial progenitor-enriched cells, thymus homing of lymphoid progenitors, and de novo thymopoiesis. RANKL increases specifically in LTi cells, lymphotoxin α, which is critical for thymic regeneration. RANKL treatment, dependent on lymphotoxin α, is beneficial upon BMT in young and aged individuals. This study thus indicates that RANKL may be clinically useful to improve T-cell function recovery after BMT by controlling multiple facets of thymic regeneration. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Radiation sensitivity of T-lymphocytes from immunodeficient wasted mice

International Nuclear Information System (INIS)

Padilla, M.; Libertin, C.; Krco, C.; Woloschak, G.E.

1990-01-01

Mice with the autosomal recessive gene wasted (wst/wst) exhibit neurologic disorders, reduced mucosal immune responses, and abnormal DNA repair mechanisms. The wst/wst mouse has been proposed as a murine model for the human disorder ataxia telangiectasia. Experiments were designed to examine the sensitivity of T-cells from wasted mice to ionizing radiation. Results demonstrated that T-cell clones derived from wasted mice are more sensitive to the killing effects of gamma-rays than similar T-cell clones from control mice. Bulk thymocyte and splenic cell cultures demonstrated similar radiation sensitivity. Both thymic and splenic lymphocytes from wasted mice also expressed low proliferative responses to mitogenic stimulation with concanavalin A (Con A) that could not be attributed to an absence or reduction in T-cell number. However, following activation with Con A, cell cultures exhibited a marked decrease in the percentage of Thyl + cells in wasted mice, in contrast to cultures from control mice in which significant increases in Thyl + cells were observed. Furthermore, when cells were treated with gamma-rays in combination with Con A, Thyl + cells were decreased in control spleen and thymus, but were elevated in similarly treated wasted cultures. These changes were accompanied by an increase in cell volume in T-cells from wasted but not from control mice. These results describe the sensitivity of T-cells from wasted mice to ionizing radiation; in addition, they suggest that the wst/wst abnormality may be associated with cell cycle aberrancies

Influence on the mouse immune system of chronic ingestion of {sup 137}Cs

Energy Technology Data Exchange (ETDEWEB)

Bertho, Jean-Marc; Faure, Marie-Cecile; Louiba, Sonia; Tourlonias, Elie; Stefani, Johanna; Siffert, Baptiste; Paquet, Francois; Dublineau, Isabelle, E-mail: Jean-marc.bertho@irsn.fr [IRSN, Laboratoire de Radiotoxicologie Experimentale, Fontenay aux Roses (France)

2011-03-01

The aim of this work was to determine the possible occurrence of damage to the immune system during the course of chronic ingestion of {sup 137}Cs. BALB/C mice were used, with {sup 137}Cs intake via drinking water at a concentration of 20 kBq l{sup -1}. Adults received {sup 137}Cs before mating and offspring were sacrificed at various ages between birth and 20 weeks. Phenotypic analysis of circulating blood cells and thymocytes did not show any significant modification of immune cell populations in animals ingesting {sup 137}Cs as compared with control animals, with the exception of a slight increase in Treg percentage at the age of 12 weeks. Functional tests, including proliferative response to mitogens such as phytohaemagglutinin, response to alloantigens in mixed lymphocyte reaction and immunoglobulin response to vaccine antigens such as tetanus toxin and keyhole limpet haemocyanin did not show any significant functional modification of the immune system in {sup 137}Cs-ingesting animals as compared with control animals. Overall, our results suggest that chronic ingestion of a low concentration of {sup 137}Cs in drinking water in the long term does not have any biologically relevant effect on the immune system.

Kalman Filter for Spinning Spacecraft Attitude Estimation

Science.gov (United States)

Markley, F. Landis; Sedlak, Joseph E.

2008-01-01

This paper presents a Kalman filter using a seven-component attitude state vector comprising the angular momentum components in an inertial reference frame, the angular momentum components in the body frame, and a rotation angle. The relatively slow variation of these parameters makes this parameterization advantageous for spinning spacecraft attitude estimation. The filter accounts for the constraint that the magnitude of the angular momentum vector is the same in the inertial and body frames by employing a reduced six-component error state. Four variants of the filter, defined by different choices for the reduced error state, are tested against a quaternion-based filter using simulated data for the THEMIS mission. Three of these variants choose three of the components of the error state to be the infinitesimal attitude error angles, facilitating the computation of measurement sensitivity matrices and causing the usual 3x3 attitude covariance matrix to be a submatrix of the 6x6 covariance of the error state. These variants differ in their choice for the other three components of the error state. The variant employing the infinitesimal attitude error angles and the angular momentum components in an inertial reference frame as the error state shows the best combination of robustness and efficiency in the simulations. Attitude estimation results using THEMIS flight data are also presented.

Corona Associations and Their Implications for Venus

Science.gov (United States)

Chapman, M.G.; Zimbelman, J.R.

1998-01-01

Geologic mapping principles were applied to determine genetic relations between coronae and surrounding geomorphologic features within two study areas in order to better understand venusian coronae. The study areas contain coronae in a cluster versus a contrasting chain and are (1) directly west of Phoebe Regio (quadrangle V-40; centered at latitude 15??S, longitude 250??) and (2) west of Asteria and Beta Regiones (between latitude 23??N, longitude 239?? and latitude 43??N, longitude 275??). Results of this research indicate two groups of coronae on Venus: (1) those that are older and nearly coeval with regional plains, and occur globally; and (2) those that are younger and occur between Beta, Atla, and Themis Regiones or along extensional rifts elsewhere, sometimes showing systematic age progressions. Mapping relations and Earth analogs suggest that older plains coronae may be related to a near-global resurfacing event perhaps initiated by a mantle superplume or plumes. Younger coronae of this study that show age progression may be related to (1) a tectonic junction of connecting rifts resulting from local mantle upwelling and spread of a quasi-stationary hotspot plume, and (2) localized spread of post-plains volcanism. We postulate that on Venus most of the young, post-resurfacing coronal plumes may be concentrated within an area defined by the bounds of Beta, Atla, and Themis Regiones. ?? 1998 Academic Press.

Exogenous origin of hydration on asteroid (16) Psyche: the role of hydrated asteroid families

Science.gov (United States)

Avdellidou, C.; Delbo', M.; Fienga, A.

2018-04-01

Asteroid (16) Psyche, which for a long time was the largest M-type with no detection of hydration features in its spectrum, was recently discovered to have a weak 3-μm band and thus it was eventually added to the group of hydrated asteroids. Its relatively high density, in combination with the high radar albedo, led researchers to classify the asteroid as a metallic object. It is believed that it is possibly a core of a differentiated body, a remnant of `hit-and-run' collisions. The detection of hydration is, in principle, inconsistent with a pure metallic origin for this body. Here, we consider the scenario in which the hydration on its surface is exogenous and was delivered by hydrated impactors. We show that impacting asteroids that belong to families whose members have the 3-μm band can deliver hydrated material to Psyche. We developed a collisional model with which we test all dark carbonaceous asteroid families, which contain hydrated members. We find that the major source of hydrated impactors is the family of Themis, with a total implanted mass on Psyche of the order of ˜1014 kg. However, the hydrated fraction could be only a few per cent of the implanted mass, as the water content in carbonaceous chondrite meteorites, the best analogue for the Themis asteroid family, is typically a few per cent of their mass.

CELESTE an atmospheric Cherenkov telescope for high energy gamma astrophysics

CERN Document Server

Paré, E; Bazer-Bachi, R; Bergeret, H; Berny, F; Briand, N; Bruel, P; Cerutti, M; Collon, J; Cordier, A; Cornebise, P; Debiais, G; Dezalay, J P; Dumora, D; Durand, E; Eschstruth, P T; Espigat, P; Fabre, B; Fleury, P; Gilly, J; Gouillaud, J C; Gregory, C; Herault, N; Holder, J; Hrabovsky, M; Incerti, S; Jouenne, A; Kalt, L; Legallou, R; Lott, B; Lodygensky, O; Manigot, P; Manseri, H; Manitaz, H; Martin, M; Morano, R; Morineaud, G; Muenz, F; Musquere, A; Naurois, M D; Neveu, J; Noppe, J M; Olive, J F; Palatka, M; Pérez, A; Quebert, J; Rebii, A; Reposeur, T; Rob, L; Roy, P; Sans, J L; Sako, T; Schovanek, P; Smith, D A; Snabre, P; Villard, G

2002-01-01

CELESTE is an atmospheric Cherenkov telescope based on the sampling method which makes use of the de-commissioned THEMIS solar electrical plant in the French Pyrenees. A large (2000 m sup 2) mirror surface area from 40 independent heliostats followed by a secondary optic, a trigger system using analog summing techniques and signal digitization with 1 GHz flash ADCs make possible the detection of cosmic gamma-rays down to 30 GeV. This paper provides a detailed technical description of the CELESTE installation.

Role of interleukin-1 in antigen presentation by normal articular chondrocytes

International Nuclear Information System (INIS)

Tiku, M.L.; Liu, S.; Tiku, K.

1986-01-01

Recently the authors have described that normal articular chondrocytes of rabbits present antigen to immune T cells. In the present study the authors investigated the role of interleukin-1 (IL-1) on antigen presentation by chondrocytes. For these experiments the antigen pulsed chondroyctes were either untreated or fixed with paraformaldehyde and then co-cultured with immune T cells. T cell proliferation was measured by 3 H-thymidine incorporation. Pulsed non-fixed chondrocytes presented antigen, as expected, but pulsed and fixed cells failed to present antigen to T cells. The 3 H-TdR incorporation was partially restored by addition of purified human IL-1. Next, IL-1 activity was measured in primary chondrocyte culture supernatants stimulated with or without lipopolysaccharide (LPS) in comitogen thymocyte assay. No activity was detected in chondrocyte supernatants. Propagated chondrocyte culture supernatants also lacked IL-1 activity when stimulated with LPS in the presence of increasing concentration of indomethacin. On the other hand the authors observed that chondrocyte culture supernatants in a dose dependent manner inhibited human IL-1 induced 3 H-TdR incorporation of murine thymocytes. This suggested that these cells may produce an inhibitor of IL-1 and IL-1 production by chondrocytes may be essential for T cell proliferation by these cells. Inability to detect IL-1 in chondrocyte supernatants may be due to the presence of an inhibitor to IL-1. These findings may help in elucidating the immunological mechanisms in situations where chondrocytes and T cell interact, such as in arthritis

Visualization of the human CD4{sup +} T-cell response in humanized HLA-DR4-expressing NOD/Shi-scid/γc{sup null} (NOG) mice by retrogenic expression of the human TCR gene

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Takeshi, E-mail: takeshi-takahashi@ciea.or.jp; Katano, Ikumi; Ito, Ryoji; Ito, Mamoru

2015-01-02

Highlights: • β-Lactoglobulin (BLG) specific TCR genes were introduced to human HSC by retrovirus. • Human HSC with BLG-specific TCR were transplanted into NOG-HLA-DR4 I-A{sup −/−} mice. • BLG-specific TCR induced positive selection of thymocytes. • BLG-specific TCR positive CD4{sup +} T cells mediated immune responses in humanized mice. - Abstract: The development of severe immunodeficient mouse strains containing various human genes, including cytokines or HLA, has enabled the reconstitution of functional human immune systems after transplantation of human hematopoietic stem cells (HSC). Accumulating evidence has suggested that HLA-restricted antigen-specific human T-cell responses can be generated in these humanized mice. To directly monitor immune responses of human CD4{sup +} T cells, we introduced β-lactoglobulin (BLG)-specific T cell receptor (TCR) genes derived from CD4{sup +} T-cell clones of cow-milk allergy patients into HSCs, and subsequently transplanted them into NOG-HLA-DR4 transgenic/I-Aβ deficient mice (NOG-DR4/I-A{sup o}). In the thymus, thymocytes with BLG-specific TCR preferentially differentiated into CD4{sup +}CD8{sup −} single-positive cells. Adoptive transfer of mature CD4{sup +} T cells expressing the TCR into recipient NOG-DR4/I-A{sup o} mice demonstrated that human CD4{sup +} T cells proliferated in response to antigenic stimulation and produced IFN-γ in vivo, suggesting that functional T-cell reactions (especially Th1-skewed responses) were induced in humanized mice.

Effect of Boron on Thymic Cytokine Expression, Hormone Secretion, Antioxidant Functions, Cell Proliferation, and Apoptosis Potential via the Extracellular Signal-Regulated Kinases 1 and 2 Signaling Pathway.

Science.gov (United States)

Jin, Erhui; Ren, Man; Liu, Wenwen; Liang, Shuang; Hu, Qianqian; Gu, Youfang; Li, Shenghe

2017-12-27

Boron is an essential trace element in animals. Appropriate boron supplementation can promote thymus development; however, a high dose of boron can lead to adverse effects and cause toxicity. The influencing mechanism of boron on the animal body remains unclear. In this study, we examined the effect of boron on cytokine expression, thymosin and thymopoietin secretion, antioxidant function, cell proliferation and apoptosis, and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway in the thymus of rats. We found that supplementation with 10 and 20 mg/L boron to the drinking water significantly elevated levels of interleukin 2 (IL-2), interferon γ (IFN-γ), interleukin 4 (IL-4), and thymosin α1 in the thymus of rats (p boron had no apparent effect on many of the above indicators. In contrast, supplementation with 480 and 640 mg/L boron had the opposite effect on the above indicators in rats and elevated levels of pro-inflammatory cytokines, such as interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNF-α) (p boron to the drinking water had a U-shaped dose-effect relationship with thymic cytokine expression, hormone secretion, antioxidant function, cell proliferation, and apoptosis. Specifically, supplementation with 10 and 20 mg/L boron promoted thymocyte proliferation and enhanced thymic functions. However, supplementation with 480 and 640 mg/L boron inhibited thymic functions and increased the number of apoptotic thymocytes, suggesting that the effects of boron on thymic functions may be caused via the ERK1/2 signaling pathway.

Opioid modulation of immunocompetence: Receptor characterization and second messenger involvement

Energy Technology Data Exchange (ETDEWEB)

Hemmick, L.M.

1989-01-01

The purpose of this thesis was to examine the effects of opioids on several indices of immunocompetence, determined the receptor specificity of these effects, and ascertain whether the actions of opioids on lymphocytes could be correlated with activation of second messenger systems. By measuring {sup 45}Ca{sup 2+} uptake into lymphocytes, it was demonstrated that {beta}-endorphin 1-31 ({beta}-END 1-31) enhanced rat thymocyte Ca{sup 2+} uptake in response to concanavalin A (Con A) but not phytohemagglutinin (PHA). Related opioid peptides and alkaloids were unable to mimic the effect, and naloxone did not block it, suggesting that {beta}-END 1-31 acted by binding to specific, non-opioid receptors on the thymocytes. Rat splenocyte Con A-stimulated Ca{sup 2+} uptake was not affected by {beta}-END 1-31. {beta}-END 1-31 did not affect basal Ca{sup 2+} uptake by either cell type. Using ({sup 3}H)thymidine uptake as an index of lymphocyte proliferation, {beta}-END 1-31 and several related opioid peptides reversed prostaglandin E{sub 1} (PGE{sub 1}) suppression of rat lymph node cell Con A- and PHA-stimulated proliferation. Naloxone did not block the reversal. {beta}-END 1-31 was unable to reverse forskolin and cholera toxin suppression of proliferation, indicating that the lowering of cyclic AMP levels was not the mechanism involved. Verapamil inhibition of proliferation was also not reversed by {beta}-END 1-31, suggesting that promotion of Ca{sup 2+} influx was not a major mechanism involved.

Poynting vector and wave vector directions of equatorial chorus

Czech Academy of Sciences Publication Activity Database

Taubenschuss, Ulrich; Santolík, Ondřej; Breuillard, H.; Li, W.; Le Contel, O.

2016-01-01

Roč. 121, č. 12 (2016), s. 11912-11928 ISSN 2169-9380 R&D Projects: GA ČR(CZ) GA14-31899S; GA MŠk(CZ) LH15304 Grant - others:AV ČR(CZ) AP1401 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:68378289 Keywords : whistler-mode waves * Earth 's inner magnetosphere * Van Allen probes * plasmaspheric hiss * magnetic reconnection * outer magnetosphere * source region * emissions * propagation * THEMIS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.733, year: 2016

The effect of ionizing radiation on lipid metabolism in lymphoid cells

International Nuclear Information System (INIS)

Kolomiytseva, I.K.; Novoselova, E.G.; Kulagina, T.P.; Kuzin, A.M.

1987-01-01

Lipid metabolism was studied in lymphoid tissues of rats after whole body irradiation with doses producing damage of different degrees to lymphoid cells (4-10 Gy). The content of free cholesterol, cholesterol esters, and total phospholipids was determined in peripheral blood lymphocytes and thymocytes 1-2 h after exposure. Simultaneously, the rate of in vitro incorporation of 2 14 C-acetate into total lipids, phospholipids, and cholesterol of lymphoid cells was estimated. It was shown that exposure of rats to ionizing radiation caused activation of lipogenesis. Cholesterol synthesis was activated after a dose of 4 Gy and decreased with increasing dose. (author)

Effect of UV-irradiation on immunological and histochemical markers of Langerhans cells in normal appearing skin of psoriatic patients

International Nuclear Information System (INIS)

Tjernlund, U.; Juhlin, L.

1982-01-01

A total of 12 patients with moderately severe psoriasis was treated with psoralen baths and/or ultraviolet radiation. Punch biopsies were taken for mimunological markers and shave biopsies for ATPase detection. As immunological marker immunosorbent purified antibodies against Ia antigens and monoclonal antigens against thymocyte antigens were used. The study showed that in the clinical relevant situation PUVA treatment had a more profound effect on the immunological markers of epidermal Langerhans cells than had light treatment without psoralens. With UV treatment without psoralens the ATPase activity of the Langerhans cells seemed to be more influenced than the immunological markers. (orig.)

Proceedings of the symposium on 'radiation research in life science'

International Nuclear Information System (INIS)

Ikushima, Takaji

1993-06-01

This report is the collection of the papers presented at the title symposium on radiation research in life science. The themes included in this report are as follows: (1) cellular aging process, (2) senescence gene and cellular immortalization, (3) molecular mechanism of replicative senescence, (4) programmed cell death during differentiation, (5) thymocyte apoptosis, (6) neuronal death, (7) apoptosis by HIV infection, (8) apoptosis and immunology, (9) radiation induced apoptosis, and so on. Separate abstract was prepared for 1 of the papers in this report. The remaining 10 papers were considered outside the subject scope of INIS. (J.P.N.)

Special AT rich-binding1 protein (SATB1) in malignant T cells

DEFF Research Database (Denmark)

Fredholm, Simon; Willerslev-Olsen, Andreas; Met, Özcan

2018-01-01

Deficient expression of Suppressor Special AT-rich Binding-1 (SATB1) hampers thymocyte development and results in inept T cell lineages. Recent data implicate dysregulated SATB1 expression in the pathogenesis of mycosis fungoides (MF), the most frequent variant of cutaneous T cell lymphoma (CTCL......) whereas increased SATB1 expression had the opposite effect indicating that the mir-155 target SATB1 is a repressor of IL-5 and IL-9 in malignant T cells. In accordance, inhibition of STAT5, and its upstream activator Janus Kinase-3 (Jak3), triggered increased SATB1 expression and a concomitant suppression...

Migration of bone marrow cells to the thymus in sublethally irradiated mice

International Nuclear Information System (INIS)

Varlet, Andree; Lenaerts, Patrick; Houben-Defresne, M.P.; Boniver, Jacques

1982-01-01

In sublethally irradiated mice, thymus repopulation is due first to the proliferation of surviving thymocytes followed by the multiplication of bone marrow derived prothymocytes. The migration of bone marrow cells to the thymus after a single sublethal whole-body X irradiation was studied by using fluorescein isothiocyanate as a cell marker. Irradiation increases the permissiveness of the thymus to the immigration of bone marrow cells. Furthermore, the post-Rx regenerating bone marrow cells exhibit migration capacities greater than the normal ones. The radiation induced changes in the bone marrow thymus interaction might play an important role in thymus regeneration after sublethal irradiation [fr

Thymic atrophy in cattle poisoned with Solanum glaucophyllum Atrofia do timo em bovinos intoxicados por Solanum glaucophyllum

Directory of Open Access Journals (Sweden)

Paula A. Fontana

2009-03-01

Full Text Available Solanum glaucophyllum (Sg [= S. malacoxylon] is a calcinogenic plant inducing "Enzootic Calcinosis" in cattle. The 1,25-dihydroxyvitamin D3, its main toxic principle, regulates bone and calcium metabolism and also exerts immunomodulatory effects. Thymocyte precursors from bone marrow-derived progenitor cells differentiate into mature T-cells. Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 receptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. Thymocytes exert a feedback influence on thymic non-lymphoid cells. Sg-induced modifications on cattle thymus T-lymphocytes and on non-lymphoid cells were analysed. Heifers were divided into 5 groups (control, intoxicated with Sg during 15, 30 or 60 days, and probably recovered group. Histochemical, immunohistochemical, lectinhistochemical and morphometric techniques were used to characterize different cell populations of the experimental heifers. Sg-poisoned heifers showed a progressive cortical atrophy that was characterized using the peanut agglutinin (PNA lectin that recognizes immature thymocytes. These animals also increased the amount of non-lymphoid cells per unit area detected with the Picrosirius technique, WGA and DBA lectins, and pancytokeratin and S-100 antibodies. The thymus atrophy found in intoxicated animals resembled that of the physiological aging process. A reversal effect on these changes was observed after suppression of the intoxication. These findings suggest that Sg-intoxication induces either directly, through the 1,25-dihydroxyvitamin D3 itself, or indirectly through the hypercalcemia, the observed alteration of the thymus.Solanum glaucophyllum (Sg [= S. malacoxylon] é uma planta calcinogênica que induz "Calcinose Enzoótica" em bovinos. O 1,25-dihidroxivitamina D3, seu principal agente tóxico, regula o

Multipotent Adult Progenitor Cells Suppress T Cell Activation in In Vivo Models of Homeostatic Proliferation in a Prostaglandin E2-Dependent Manner

Science.gov (United States)

Carty, Fiona; Corbett, Jennifer M.; Cunha, João Paulo M. C. M.; Reading, James L.; Tree, Timothy I. M.; Ting, Anthony E.; Stubblefield, Samantha R.; English, Karen

2018-01-01

Lymphodepletion strategies are used in the setting of transplantation (including bone marrow, hematopoietic cell, and solid organ) to create space or to prevent allograft rejection and graft versus host disease. Following lymphodepletion, there is an excess of IL-7 available, and T cells that escape depletion respond to this cytokine undergoing accelerated proliferation. Moreover, this environment promotes the skew of T cells to a Th1 pro-inflammatory phenotype. Existing immunosuppressive regimens fail to control this homeostatic proliferative (HP) response, and thus the development of strategies to successfully control HP while sparing T cell reconstitution (providing a functioning immune system) represents a significant unmet need in patients requiring lymphodepletion. Multipotent adult progenitor cells (MAPC®) have the capacity to control T cell proliferation and Th1 cytokine production. Herein, this study shows that MAPC cells suppressed anti-thymocyte globulin-induced cytokine production but spared T cell reconstitution in a pre-clinical model of lymphodepletion. Importantly, MAPC cells administered intraperitoneally were efficacious in suppressing interferon-γ production and in promoting the expansion of regulatory T cells in the lymph nodes. MAPC cells administered intraperitoneally accumulated in the omentum but were not present in the spleen suggesting a role for soluble factors. MAPC cells suppressed lymphopenia-induced cytokine production in a prostaglandin E2-dependent manner. This study suggests that MAPC cell therapy may be useful as a novel strategy to target lymphopenia-induced pathogenic T cell responses in lymphodepleted patients. PMID:29740426

The effect of conditional EFNB1 deletion in the T cell compartment on T cell development and function

Directory of Open Access Journals (Sweden)

Jin Wei

2011-12-01

Full Text Available Abstract Background Eph kinases are the largest family of cell surface receptor tyrosine kinases. The ligands of Ephs, ephrins (EFNs, are also cell surface molecules. Ephs interact with EFNs transmitting signals in both directions, i.e., from Ephs to EFNs and from EFNs to Ephs. EFNB1 is known to be able to co-stimulate T cells in vitro and to modulate thymocyte development in a model of foetal thymus organ culture. To further understand the role of EFNB1 in T cell immunity, we generated T-cell-specific EFNB1 gene knockout mice to assess T cell development and function in these mice. Results The mice were of normal size and cellularity in the thymus and spleen and had normal T cell subpopulations in these organs. The bone marrow progenitors from KO mice and WT control mice repopulated host spleen T cell pool to similar extents. The activation and proliferation of KO T cells was comparable to that of control mice. Naïve KO CD4 cells showed an ability to differentiate into Th1, Th2, Th17 and Treg cells similar to control CD4 cells. Conclusions Our results suggest that the function of EFNB1 in the T cell compartment could be compensated by other members of the EFN family, and that such redundancy safeguards the pivotal roles of EFNB1 in T cell development and function.

A Basketball Court-Size Global Map of Mars for Education and Public Outreach

Science.gov (United States)

Hill, J. R.; Christensen, P. R.

2017-12-01

The Thermal Emission Imaging System (THEMIS) onboard the 2001 Mars Odyssey spacecraft has acquired over 220,000 infrared images of the Martian surface at a resolution of 100 m/pixel since the start of science operations in February 2002. A global map was previously developed by mosaicking together over 24,000 high-quality full-resolution THEMIS daytime infrared images. Although the resulting map has been extremely valuable for scientific and mission operations applications, it has been difficult to communicate this value to students, citizen scientists and the general public, since their interactions with the map have been limited to computer-based geographic information system (GIS) interfaces. We determined that, in order to better communicate the value and importance of mapping the entire Martian surface at this resolution, people need to be able to physically interact with the map and experience its full scale. Therefore, the THEMIS Day IR Global Mosaic with Colorized MOLA Elevation will be printed on a 45ft x 90ft vinyl mat, which will allow observers to walk across and physically experience the map at approximately full resolution (printed at 200 pixels per inch). The size of the map was chosen to fit on a standard high school basketball court, so that a large number of schools will have a sufficiently large indoor surface on which to display the map for education events. The vinyl material and printing process selected for the map have been proven to be wear-resistant in similar applications, as long as everyone who walks on the map wears socks or similarly soft foot coverings. In order to make transportation easier, the map will be printed in two 45ft x 45ft sections, which will be joined together at events to create the full 45ft x 90ft map. The final stages of the map production will take place in early fall 2017, followed by initial education events at Arizona State University and local schools to test the educational activities associated with the map

Prediction Model of the Outer Radiation Belt Developed by Chungbuk National University

Directory of Open Access Journals (Sweden)

Dae-Kyu Shin

2014-12-01

Full Text Available The Earth’s outer radiation belt often suffers from drastic changes in the electron fluxes. Since the electrons can be a potential threat to satellites, efforts have long been made to model and predict electron flux variations. In this paper, we describe a prediction model for the outer belt electrons that we have recently developed at Chungbuk National University. The model is based on a one-dimensional radial diffusion equation with observationally determined specifications of a few major ingredients in the following way. First, the boundary condition of the outer edge of the outer belt is specified by empirical functions that we determine using the THEMIS satellite observations of energetic electrons near the boundary. Second, the plasmapause locations are specified by empirical functions that we determine using the electron density data of THEMIS. Third, the model incorporates the local acceleration effect by chorus waves into the one-dimensional radial diffusion equation. We determine this chorus acceleration effect by first obtaining an empirical formula of chorus intensity as a function of drift shell parameter L*, incorporating it as a source term in the one-dimensional diffusion equation, and lastly calibrating the term to best agree with observations of a certain interval. We present a comparison of the model run results with and without the chorus acceleration effect, demonstrating that the chorus effect has been incorporated into the model to a reasonable degree.

Relationship between microstructure, cytotoxicity and corrosion properties of a Cu-Al-Ni shape memory alloy.

Science.gov (United States)

Colić, Miodrag; Rudolf, Rebeka; Stamenković, Dragoslav; Anzel, Ivan; Vucević, Dragana; Jenko, Monika; Lazić, Vojkan; Lojen, Gorazd

2010-01-01

Cu-Al-Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but their biomedical application is still limited. The aim of this work was to compare the microstructure, corrosion and cytotoxicity in vitro of a Cu-Al-Ni SMA. Rapidly solidified (RS) thin ribbons, manufactured via melt spinning, were used for the tests. The control alloy was a permanent mould casting of the same composition, but without shape memory effect. The results show that RS ribbons are significantly more resistant to corrosion compared with the control alloy, as judged by the lesser release of Cu and Ni into the conditioning medium. These results correlate with the finding that RS ribbons were not cytotoxic to L929 mouse fibroblasts and rat thymocytes. In addition, the RS ribbon conditioning medium inhibited cellular proliferation and IL-2 production by activated rat splenocytes to a much lesser extent. The inhibitory effects were almost completely abolished by conditioning the RS ribbons in culture medium for 4 weeks. Microstructural analysis showed that RS ribbons are martensitic, with boron particles as a minor phase. In contrast, the control Cu-Al-Ni alloy had a complex multiphase microstructure. Examination of the alloy surfaces after conditioning by energy dispersive X-ray and Auger electron spectroscopy showed the formation of Cu and Al oxide layers and confirmed that the metals in RS ribbons are less susceptible to oxidation and corrosion compared with the control alloy. In conclusion, these results suggest that rapid solidification significantly improves the corrosion stability and biocompatibility in vitro of Cu-Al-Ni SMA ribbons.

The origin of the 3.4 micron feature in Wild 2 cometary particles and in ultracarbonaceous interplanetary dust particles

OpenAIRE

Matrajt, Graciela; Flynn, George; Brownlee, Don; Joswiak, Dave; Bajt, Sasa

2013-01-01

We analyzed 2 ultra-carbonaceous interplanetary dust particles and 2 cometary Wild 2 particles with infrared spectroscopy. We characterized the carrier of the 3.4 micron band in these samples and compared its profile and the CH2/CH3 ratios to the 3.4 micron band in the diffuse interstellar medium (DISM), in the insoluble organic matter (IOM) from 3 primitive meteorites, in asteroid 24 Themis and in the coma of comet 103P/Hartley 2. We found that the 3.4 micron band in both Wild 2 and IDPs is ...

Mercury sodium exospheric emission as a proxy for solar perturbations transit

Science.gov (United States)

Orsini, S.; Mangano, V.; Milillo, A.; Plainaki, C.; Mura, A.; Raines, J. M.; Laurenza, M.; De Angelis, E.; Rispoli, R.; Lazzarotto, F.; Aronica, A.

2017-12-01

The first evidence at Mercury of direct relation between ICME transit and Na exosphere dynamics is presented, suggesting that Na emission, observed from ground, could be a proxy of planetary space weather at Mercury. The link existing between the dayside exosphere Na patterns and the solar wind-magnetosphere-surface interactions is investigated. This goal is pursued by analyzing the Na intensity hourly images, as observed by the ground-based THEMIS solar telescope (Mangano et al., 2015*) during 10 selected periods between 2012 and 2013 (with seeing, σ 10.1016/j.pss.2015.04.001, 2015.

The ARTEMIS mission

CERN Document Server

Angelopoulos, Vassilis

2014-01-01

The ARTEMIS mission was initiated by skillfully moving the two outermost Earth-orbiting THEMIS spacecraft into lunar orbit to conduct unprecedented dual spacecraft observations of the lunar environment. ARTEMIS stands for Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun. Indeed, this volume discusses initial findings related to the Moon’s magnetic and plasma environments and the electrical conductivity of the lunar interior. This work is aimed at researchers and graduate students in both heliophysics and planetary physics. Originally published in Space Science Reviews, Vol. 165/1-4, 2011.

Magnetic holes in the dipolarized magnetotail: ion and electron anisotropies

Science.gov (United States)

Shustov, P.; Artemyev, A.; Zhang, X. J.; Yushkov, E.; Petrukovich, A. A.

2017-12-01

We conduct statistics on magnetic holes observed by THEMIS spacecraft in the near-Earth magnetotail. Groups of holes are detected after dipolarizations in the quiet, equatorial plasma sheet. Magnetic holes are characterized by significant magnetic field depressions (up to 50%) and strong electron currents ( 10-50 nA/m2), with spatial scales much smaller than the ion gyroradius. These magnetic holes are populated by hot (>10 keV), transversely anisotropic electrons supporting the pressure balance. We present statistical properties of these sub-ion scale magnetic holes and discuss possible mechanisms on the hole formation.

The effects of spaceflight and Insulin-like Growth Factor-1 on the T-cell and macrophage populations

Energy Technology Data Exchange (ETDEWEB)

Pecaut, M.J.; Simske, S.J. [BioServe Space Technologies Engineering Center Campus Box 429 University of Colorado Boulder, Colorado80309 (United States); Fleshner, M. [Laboratory of Behavioral Neuroscience Department of Psychology Campus Box 345 University of Colorado Boulder, Colorado80309 (United States); Zimmerman, R. [Chiron Corporation, 4560 Horton St., Emeryville, California94025 (United States)

1997-01-01

Twelve Sprague-Dawley rats were flown aboard the Space Shuttle Endeavor (STS-77) to study the effects of microgravity-induced stress on the immunoskeletal system. Sixteen rats were used as simultaneous vivarium ground controls during the ten day mission. Osmotic pumps, half of which contained Insulin-like Growth Factor-1 (IGF-1, provided by Chiron), were surgically implanted (subcutaneous) into the rats prior to launch in an attempt to counter any stress effects. On the day of landing, the rats were sacrificed and dissected. Splenocytes and thymocytes were labeled with antibodies against CD4, CD8, CD11b, and TCR for flow cytometry. The percentage of splenic cytotoxic/suppressor (TCR+/CD8+) T-cells increased significantly (by 118{percent}) in spaceflight. There were also decreases in splenic helper (TCR+/CD4+) T-cells and (CD11b+) macrophages (by 33{percent} and 38{percent}, respectively). Together, these results suggest the stress of spaceflight could cause a significant decrease in the ability of rats to mount an immune response. The effects of IGF-1 on cell population distributions were negligible for both flight and vivarium ground controls. However, there were significant differences in spleen and thymus masses suggesting that while IGF-1 did not effect population distributions, the drug may have caused an increase in population size. {copyright} {ital 1997 American Institute of Physics.}

Induction of specific unresponsiveness to heart allografts in mongrel dogs treated with total lymphoid irradiation and antithymocyte globulin

International Nuclear Information System (INIS)

Strober, S.; Modry, D.L.; Hoppe, R.T.

1984-01-01

The survival of heterotopic heart allografts was determined in mongrel dogs treated with total lymphoid irradiation (TLI) alone or in combination with other immunosuppressive agents. TLI alone (total dose, 1800 rad) minimally prolonged graft survival as compared with untreated controls. However, marked synergy was observed when TLI was combined with a 10-day post-transplant course of rabbit anti-dog thymocyte globulin (ATG). Approximately 40% of recipients given TLI and ATG showed specific unresponsiveness, as judged by the lack of rejection on serial biopsies for more than 1 year and the prompt rejection of third party hearts. The addition of post-transplant azathioprine (90 to 180 days) to the TLI and ATG regimen increased the mortality of recipients and reduced the fraction of dogs showing specific unresponsiveness. Infusion of donor bone marrow cells at the time of heart transplantation failed to induced specific unresponsiveness in recipients given TLI alone or TLI in combination with post-transplant methotrexate, cyclosporine A, or ATG. The results indicate that the combination of TLI and a brief course of ATG without marrow transplantation was the most effective regimen for the induction of specific unresponsiveness in mongrel dogs

T lymphocytes from irradiation chimeras repopulated with 13-day fetal liver cells recognize antigens only in association with self-MHC products

International Nuclear Information System (INIS)

Nisbet-Brown, E.; Diener, E.

1986-01-01

The restriction specificities of maturing thymocytes are determined by the Class II MHC antigens expressed by non-lymphoid thymic tissues. The proliferative response of mature T lymphocytes to antigen-presenting cells (APC) and antigen requires that the APC express the same MHC antigens as the thymus in which the T cells differentiated. Thus, in the two-way bone marrow chimera [A + B----(A x B)F1], T lymphocyte populations of A and B haplotypes have each acquired the potential to recognize antigens associated with either parental haplotype. In spite of the large body of work on MHC restriction, we still do not have a clear understanding of the mechanisms which impose self restriction. The chimeric model systems used previously to study MHC restriction have used adult bone marrow cells as the source of lymphoid precursors. During normal ontogeny, T cells are derived from precursors in the fetal liver and we felt that a direct comparison of T cells from fetal liver and bone marrow-repopulated animals would shed light on the development of MHC restriction specificities during T cell ontogeny in the thymus or prethymically. We found that parental T lymphocyte populations isolated from two-way fetal liver chimeras cooperated only with syngeneic APC, while those from bone marrow chimeras cooperated with APC of either parental haplotype. This suggests that fetal liver and bone marrow may not be equivalent sources of stem cells. Our results may be due to fundamental differences between thymocyte precursors in fetal liver and bone marrow, including the time course of their expression of T cell receptor gene products

Adipocyte and leptin accumulation in tumor-induced thymic involution.

Science.gov (United States)

Lamas, Alejandro; Lopez, Elena; Carrio, Roberto; Lopez, Diana M

2016-01-01

Cell-mediated immunity is an important defense mechanism against pathogens and developing tumor cells. The thymus is the main lymphoid organ involved in the formation of the cell-mediated immune response by the maturation and differentiation of lymphocytes that travel from the bone marrow, through the lymphatic ducts, to become T lymphocytes. Thymic involution has been associated with aging; however, other factors such as obesity, viral infection and tumor development have been shown to increase the rate of shrinkage of this organ. The heavy infiltration of adipocyte fat cells has been reported in the involuted thymuses of aged mice. In the present study, the possible accumulation of such cells in the thymus during tumorigenesis was examined by immunohistochemistry. A significant number of adipocytes around and infiltrating the thymuses of tumor-bearing mice was observed. Leptin is a pro-inflammatory adipocytokine that enhances thymopoiesis and modulates T cell immune responses. The levels of leptin and adiponectin, another adipocytokine that has anti-inflammatory properties, were examined by western blot analysis. While no changes were observed in the amounts of adiponectin present in the thymuses of the normal and tumor-bearing mice, significantly higher levels of leptin were detected in the thymocytes of the tumor-bearing mice. This correlated with an increase in the expression of certain cytokines, such as interleukin (IL)-2, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF). The co-culture of thymocytes isolated from normal mice with ex vivo isolated adipocytes from tumor-bearing mice yielded similar results. Our findings suggest that the infiltration and accumulation of adipocytes in the thymuses of tumor-bearing mice play an important role in their altered morphology and functions.

T cell differentiation stages identified by molecular and immunologic analysis of the T cell receptor complex in childhood lymphoblastic leukemia.

Science.gov (United States)

Mirro, J; Kitchingman, G; Behm, F G; Murphy, S B; Goorha, R M

1987-03-01

T cell differentiation was investigated by determining the relationship of T cell receptor (Ti) gene rearrangement and transcription to the expression of surface and cytoplasmic T3 antigen using blast cells from five children with acute lymphoblastic leukemia of thymic origin. Patterns of monoclonal antibody (MoAb) reactivity indicated that these cases were representative of the three recognized stages (I, II, III) of human thymocyte development. The T3 antigen, which becomes linked to the Ti to form a functional T cell receptor complex on mature thymocytes, was expressed on the cell surface in two cases (stage III). However, in the remaining three cases that were surface T3 negative (stages I and II), large amounts of T3 were identified in the cytoplasm by immunoperoxidase staining and flow cytometry. Leukemic blasts from all five patients showed rearranged genes encoding the beta-chain portion of the Ti heterodimer. RNA transcripts of Ti beta-chain genes were also evident in lymphoblasts from all five cases, but transcripts coding for the alpha-chain portion of Ti were found only in cases that expressed T3 on the cell surface. Thus the absence of surface T3 (and presumably Ti) coincides with the absence of Ti alpha-chain RNA, suggesting that transcription of alpha-chain genes is a critical regulatory event in the surface expression of the Ti-T3 complex. Leukemic T cells that rearrange and express Ti beta-chain genes but lack Ti alpha-chain messenger RNA (mRNA) may represent a stage of differentiation analogous to pre-B cells, where heavy-chain immunoglobulin (Ig) genes are rearranged and expressed but light-chain Ig genes are not expressed.

Large-scale multiplex polymerase chain reaction assay for diagnosis of viral reactivations after allogeneic hematopoietic stem cell transplantation.

Science.gov (United States)

Inazawa, Natsuko; Hori, Tsukasa; Hatakeyama, Naoki; Yamamoto, Masaki; Yoto, Yuko; Nojima, Masanori; Suzuki, Nobuhiro; Shimizu, Norio; Tsutsumi, Hiroyuki

2015-08-01

Viral reactivations following hematopoietic stem cell transplantation are thought to result from the breakdown of both cell-mediated and humoral immunity. As a result, many viruses could be reactivated individually or simultaneously. Using a multiplex polymerase chain reaction (PCR), we prospectively examined many kinds of viral DNAs at a time in 105 patients who underwent allogeneic hematopoietic stem cell transplantation. In total, 591 whole blood samples were collected weekly from pre- to 42 days post-transplantation and the following 13 viruses were tested; herpes simplex virus 1 (HSV-1), HSV-2, varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, HHV-8, adenovirus, BK virus (BKV), JC virus (JCV), parvovirus B19, and hepatitis B virus (HBV). Several viral DNAs were detected in 12 patients before hematopoietic stem cell transplantation. The detection rate gradually increased after transplantation and peaked at 21 days. The most frequently detected virus was HHV-6 (n = 63; 60.0%), followed by EBV (n = 11; 10.5%), CMV (n = 11; 10.5%), and HHV-7 (n = 9; 8.6%). Adenovirus and HBV were each detected in one patient (1.0%). Detection of HHV-6 DNA was significantly more common among patients undergoing cord blood transplantation or with steroid treatment. EBV DNA tended to be more common in patients treated with anti-thymocyte globulin. Multiplex PCR was useful for detecting many viral reactivations after hematopoietic stem cell transplantation, simultaneously. Cord blood transplantation, steroid treatment, or anti-thymocyte globulin use was confirmed to be risk factors after transplantation. © 2015 Wiley Periodicals, Inc.

Changes in plasma membrane state of thymocytes during spontaneous and radiation-induced leukemogenesis

International Nuclear Information System (INIS)

Gonta-Grabiec, K.

1984-01-01

Changes in plasma membrane properties characteristic for malignant cells were reviewed. Investigations of spontaneous (in AKR mice) and radiation-induced (in C57Bl) leukemogenesis were carried out; changes in properties of Na + , K + ATPase and alkaline phosphatase were characterized. On the basis of the results reported a pre-leukemic stage was distinguished, corresponding to the following features at the cellular level: increase in activity of alkaline phosphatase; decrease in relative activity of Na + , K + ATPase; decrease in efficiency of the Na + K + pump; decrease in cAMP content. 473 refs. (author)

Thymocyte plasma membrane of the rainbow trout, Salmo gairdneri: Associated immunoglobulin and heteroantigens

Science.gov (United States)

Warr, G.W.; DeLuca, D.; Anderson, D.P.

1983-01-01

1. Thymic lymphocytes of the rainbow trout, S. gairdneri were disrupted and a plasma membrane containing fraction isolated by differential and buoyant density centrifugation.2. Radioiodine introduced into the membrane by the lactoperoxidase catalyzed reaction and immunoglobulin (identified by radioimmunoassay with monoclonal antibody) both copurified in the plasma membrane fraction.3. Rabbit antibody raised to the plasma membrane fraction showed a strong reaction with trout lymphocytes in immunofluorescence, was mitogenic for trout lymphocytes, and recognized lymphocyte membrane heteroantigens of molecular weight > 70,000 in the thymus and 45,000–95,000 in the head kidney.

Effect of intratracheally instilled depleted uranium on immunological function of rats

International Nuclear Information System (INIS)

You Hanhu; Yang Zhihua; Cao Zhenshan; Zhu Maoxiang; Liu Xingrong

2004-01-01

Objective: To study immunological effects of depleted uranium in rats. Methods: Wistar rats were exposed to depleted uranium by single intratracheal instillation. Body weight and peripheral blood cells were measured weekly and immunological functions were evaluated by weight coefficient of immune organs, plague forming cells of splenocytes, total and subpopulation counts of lymphocytes in thymus. Results: Early after administration, body weight decreased and red blood cells as well as platelets reduced while white blood cells increased, which returned to normal within 1 or 2 months. Immunological functions of splenocytes and thymocytes were affected dose-dependently by depleted uranium. Conclusion: Depleted uranium induces immunological dysfunction in rats. (authors)

Thymus Atrophy and Double-Positive Escape Are Common Features in Infectious Diseases

Directory of Open Access Journals (Sweden)

Juliana de Meis

2012-01-01

Full Text Available The thymus is a primary lymphoid organ in which bone marrow-derived T-cell precursors undergo differentiation, leading to migration of positively selected thymocytes to the T-cell-dependent areas of secondary lymphoid organs. This organ can undergo atrophy, caused by several endogenous and exogenous factors such as ageing, hormone fluctuations, and infectious agents. This paper will focus on emerging data on the thymic atrophy caused by infectious agents. We present data on the dynamics of thymus lymphocytes during acute Trypanosoma cruzi infection, showing that the resulting thymus atrophy comprises the abnormal release of thymic-derived T cells and may have an impact on host immune response.

On postirradiation desensitization of the organism to adrenaline

International Nuclear Information System (INIS)

Vasin, M.V.; Petrova, T.V.

1988-01-01

In experiments with albino mongrel rats weighing 220-260 g a study was made of the affect of adrenaline on the cyclic nucleotide content of blood plasma at early times following 60 Co gamma-irradiation (75 Gy). The absence of the organism response to adrenaline is perhaps due to the development of post irradiation desensitization of β-adrenergic system and inability to induce cAMP formation in a cell. The data are submitted confirming the affect of levamisole on the cyclic nucleitide level. The level of cGMP decreased in thymocytes and increased in blood plasma after the administration of the drug to irradiated animals

Effects of Acute Low-Dose Exposure to the Chlorinated Flame Retardant Dechlorane 602 and Th1 and Th2 Immune Responses in Adult Male Mice.

Science.gov (United States)

Feng, Yu; Tian, Jijing; Xie, Heidi Qunhui; She, Jianwen; Xu, Sherry Li; Xu, Tuan; Tian, Wenjing; Fu, Hualing; Li, Shuaizhang; Tao, Wuqun; Wang, Lingyun; Chen, Yangsheng; Zhang, Songyan; Zhang, Wanglong; Guo, Tai L; Zhao, Bin

2016-09-01

Although the chlorinated flame retardant Dechlorane (Dec) 602 has been detected in food, human blood, and breast milk, there is limited information on potential health effects, including possible immunotoxicity. We determined the immunotoxic potential of Dec 602 in mice by examining the expression of phenotypic markers on thymocyte and splenic lymphocyte subsets, Th1/Th2 transcription factors, and the production of cytokines and antibodies. Adult male C57BL/6 mice were orally exposed to environmentally relevant doses of Dec 602 (1 and 10 μg/kg body weight per day) for 7 consecutive days. Thymocyte and splenic CD4 and CD8 subsets and splenocyte apoptosis were examined by flow cytometric analysis. Cytokine expression was measured at both the mRNA and the protein levels. Levels of the transcription factors Th1 (T-bet and STAT1) and Th2 (GATA3) were determined using quantitative real-time polymerase chain reaction (qPCR). Serum levels of immunoglobulins IgG1, IgG2a, IgG2b and IgE were measured by enzyme-linked immunosorbent assay (ELISA). Splenic CD4+ and CD8+ T cell subsets were decreased compared with vehicle controls, and apoptosis was significantly increased in splenic CD4+ T cells. Expression (mRNA and protein) of Th2 cytokines [interleukin (IL)-4, IL-10, and IL-13] increased, and that of Th1 cytokines [IL-2, interferon (IFN)-γ and tumor necrosis factor (TNF)-α] decreased. The Th2 transcriptional factor GATA3 increased, whereas the Th1 transcriptional factors T-bet and STAT1 decreased. As additional indicators of the Th2-Th1 imbalance, production of IgG1 was significantly increased, whereas IgG2a was reduced. To our knowledge, we are the first to report evidence of the effects of Dec 602 on immune function in mice, with findings indicating that Dec 602 exposure favored Th2 responses and reduced Th1 function. Feng Y, Tian J, Xie HQ, She J, Xu SL, Xu T, Tian W, Fu H, Li S, Tao W, Wang L, Chen Y, Zhang S, Zhang W, Guo TL, Zhao B. 2016. Effects of acute low

Cellular analysis of the phenotypic correction of the genetically controlled low immune response to the polyproline determinant by macrophages

International Nuclear Information System (INIS)

Falkenberg, F.W.; Sulica, A.; Shearer, G.M.; Mozes, E.; Sela, M.

1974-01-01

SJL mice are high responders to the polyproline region of poly(Tyr,Glu)-polyPro-polyLys, (T,G)-Pro-L and of poly(Phe,Glu)-polyPro-polyLys, (Phe,G)-Pro-L, whereas DBA/l mice are the low responders to this moiety. The low responsiveness of DBA/l mice to polyproline could be enhanced by immunization with (T,G)-Pro-L 4 days after stimulation of peritoneal cells by thioglycolate. The same effect was observed when DBA/l mice were immunized with 10 7 syngeneic peritoneal exudate cells (PEC) preincubated in vitro with the immunogen. Similar treatments of SJL mice did not enhance the high response to polyproline, nor did it enhance low responses to other synthetic polypeptides tested. The enhancing effect of PEC on immunocompetent cells was established by transferring graded numbers of spleen cells together with 10 7 PEC into irradiated syngeneic DBA/l recipients. The effective cell type in the PEC was found to be the macrophage as the same results were observed with the adherent-cell population. Furthermore, the effect was not abolished after in vitro irradiation of PEC with 5000 R or by anti-theta treatment. In vivo irradiation of the PEC donors 2 days before the cells were harvested also did not influence the phenotypic correction of the low responsiveness. Transfer experiments in which graded inocula of either marrow cells or thymocytes from DBA/l donors were transferred into syngeneic recipients in the presence of an excess of the complementary cell type together with PEC indicated that the enhancing effect was reflected in the bone-marrow-cell population only

MAGNETIC FIELD IN ATYPICAL PROMINENCE STRUCTURES: BUBBLE, TORNADO, AND ERUPTION

Energy Technology Data Exchange (ETDEWEB)

Levens, P. J.; Labrosse, N. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Schmieder, B. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France); López Ariste, A. [IRAP—CNRS UMR 5277, 14, Av. E. Belin, F-31400 Toulouse (France); Dalmasse, K. [CISL/HAO, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States); Gelly, B., E-mail: p.levens.1@research.gla.ac.uk, E-mail: brigitte.schmieder@obspm.fr [CNRS UMR 3718 THEMIS, La Laguna, Tenerife (Spain)

2016-08-01

Spectropolarimetric observations of prominences have been obtained with the THEMIS telescope during four years of coordinated campaigns. Our aim is now to understand the conditions of the cool plasma and magnetism in “atypical” prominences, namely when the measured inclination of the magnetic field departs, to some extent, from the predominantly horizontal field found in “typical” prominences. What is the role of the magnetic field in these prominence types? Are plasma dynamics more important in these cases than the magnetic support? We focus our study on three types of “atypical” prominences (tornadoes, bubbles, and jet-like prominence eruptions) that have all been observed by THEMIS in the He i D{sub 3} line, from which the Stokes parameters can be derived. The magnetic field strength, inclination, and azimuth in each pixel are obtained by using the inversion method of principal component analysis on a model of single scattering in the presence of the Hanle effect. The magnetic field in tornadoes is found to be more or less horizontal, whereas for the eruptive prominence it is mostly vertical. We estimate a tendency toward higher values of magnetic field strength inside the bubbles than outside in the surrounding prominence. In all of the models in our database, only one magnetic field orientation is considered for each pixel. While sufficient for most of the main prominence body, this assumption appears to be oversimplified in atypical prominence structures. We should consider these observations as the result of superposition of multiple magnetic fields, possibly even with a turbulent field component.

ERRATUM: Propagating Waves Transverse to the Magnetic Field in a Solar Prominence

Science.gov (United States)

Schmieder, B.; Kucera, T. A.; Knizhnik, K.; Luna, M.; Lopez-Ariste, A.; Toot, D.

2014-01-01

We report an unusual set of observations of waves in a large prominence pillar that consist of pulses propagating perpendicular to the prominence magnetic field. We observe a huge quiescent prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly in EUV on 2012 October 10 and only a part of it, the pillar, which is a foot or barb of the prominence, with the Hinode Solar Optical Telescope (SOT; in Ca II and Halpha lines), Sac Peak (in Ha, Hß, and Na-D lines), and THEMIS ("Télescope Héliographique pour l' Etude du Magnétisme et des Instabilités Solaires") with the MTR (MulTi-Raies) spectropolarimeter (in He D3 line). The THEMIS/MTR data indicates that the magnetic field in the pillar is essentially horizontal and the observations in the optical domain show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data over the four hour observing period show vertical oscillations appearing as wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along thin quasi-vertical columns in the much broader pillar. The pulses have a velocity of propagation of about 10 km/s, a period of about 300 s, and a wavelength around 2000 km. We interpret these waves in terms of fast magnetosonic waves and discuss possible wave drivers.

3D Evolution of a Filament Disappearance Event Observed by STEREO

Science.gov (United States)

Gosain, S.; Schmieder, B.; Venkatakrishnan, P.; Chandra, R.; Artzner, G.

2009-10-01

A filament disappearance event was observed on 22 May 2008 during our recent campaign JOP 178. The filament, situated in the Southern Hemisphere, showed sinistral chirality consistent with the hemispheric rule. The event was well observed by several observatories, in particular by THEMIS. One day, before the disappearance, Hα observations showed up- and down-flows in adjacent locations along the filament, which suggest plasma motions along twisted flux rope. THEMIS and GONG observations show shearing photospheric motions leading to magnetic flux canceling around barbs. STEREO A, B spacecraft with separation angle 52.4°, showed quite different views of this untwisting flux rope in He ii 304 Å images. Here, we reconstruct the three-dimensional geometry of the filament during its eruption phase using STEREO EUV He ii 304 Å images and find that the filament was highly inclined to the solar normal. The He ii 304 Å movies show individual threads, which oscillate and rise to an altitude of about 120 Mm with apparent velocities of about 100 km s-1 during the rapid evolution phase. Finally, as the flux rope expands into the corona, the filament disappears by becoming optically thin to undetectable levels. No CME was detected by STEREO, only a faint CME was recorded by LASCO at the beginning of the disappearance phase at 02:00 UT, which could be due to partial filament eruption. Further, STEREO Fe xii 195 Å images showed bright loops beneath the filament prior to the disappearance phase, suggesting magnetic reconnection below the flux rope.

Pitch angle distributions of electrons at dipolarization sites during geomagnetic activity: THEMIS observations

Science.gov (United States)

Wang, Kaiti; Lin, Ching-Huei; Wang, Lu-Yin; Hada, Tohru; Nishimura, Yukitoshi; Turner, Drew L.; Angelopoulos, Vassilis

2014-12-01

Changes in pitch angle distributions of electrons with energies from a few eV to 1 MeV at dipolarization sites in Earth's magnetotail are investigated statistically to determine the extent to which adiabatic acceleration may contribute to these changes. Forty-two dipolarization events from 2008 and 2009 observed by Time History of Events and Macroscale Interactions during Substorms probes covering the inner plasma sheet from 8 RE to 12 RE during geomagnetic activity identified by the AL index are analyzed. The number of observed events with cigar-type distributions (peaks at 0° and 180°) decreases sharply below 1 keV after dipolarization because in many of these events, electron distributions became more isotropized. From above 1 keV to a few tens of keV, however, the observed number of cigar-type events increases after dipolarization and the number of isotropic events decreases. These changes can be related to the ineffectiveness of Fermi acceleration below 1 keV (at those energies, dipolarization time becomes comparable to electron bounce time). Model-calculated pitch angle distributions after dipolarization with the effect of betatron and Fermi acceleration tested indicate that these adiabatic acceleration mechanisms can explain the observed patterns of event number changes over a large range of energies for cigar events and isotropic events. Other factors still need to be considered to assess the observed increase in cigar events around 2 keV. Indeed, preferential directional increase/loss of electron fluxes, which may contribute to the formation of cigar events, was observed. Nonadiabatic processes to accelerate electrons in a parallel direction may also be important for future study.

Relation of major volcanic center concentration on Venus to global tectonic patterns

Science.gov (United States)

Crumpler, L. S.; Head, James W.; Aubele, Jayne C.

1993-01-01

Global analysis of Magellan image data indicates that a major concentration of volcanic centers covering about 40 percent of the surface of Venus occurs between the Beta, Atla, and Themis regions. Associated with this enhanced concentration are geological characteristics commonly interpreted as rifting and mantle upwelling. Interconnected low plains in an annulus around this concentration are characterized by crustal shortening and infrequent volcanic centers that may represent sites of mantle return flow and net downwelling. Together, these observations suggest the existence of relatively simple, large-scale patterns of mantle circulation similar to those associated with concentrations of intraplate volcanism on earth.

Optimal Design of Piezoelectric Materials for Maximal Energy Harvesting

Science.gov (United States)

2015-06-01

constant coefficients consists of two parts, the complementary function, which is the solution of the corresponding homogeneous equation, and the...mY0ω2 cos(ωt) . (2.6) Matching the coefficients for cos(ωt) and sin(ωt), respectively, we find ( Ak−Amω2 ) cosφ +Adω sinφ = mY0ω2, (2.7)( k−mω2 ) sinφ...trical vibration based generator. Their design uses an 8.44 gram mass and a two-layer sheet of PZT -5A with a steel center shim excited by vibrations of

Exposure of Jurkat cells to bis (tri-n-butyltin) oxide (TBTO) induces transcriptomics changes indicative for ER- and oxidative stress, T cell activation and apoptosis

International Nuclear Information System (INIS)

Katika, Madhumohan R.; Hendriksen, Peter J.M.; Loveren, Henk van; Peijnenburg, Ad

2011-01-01

Tributyltin oxide (TBTO) is an organotin compound that is widely used as a biocide in agriculture and as an antifouling agent in paints. TBTO is toxic for many cell types, particularly immune cells. The present study aimed to identify the effects of TBTO on the human T lymphocyte cell line Jurkat. Cells were treated with 0.2 and 0.5 μM TBTO for 3, 6, 12 and 24 h and then subjected to whole genome gene expression microarray analysis. The biological interpretation of the gene expression profiles revealed that endoplasmic reticulum (ER) stress is among the earliest effects of TBTO. Simultaneously or shortly thereafter, oxidative stress, activation of NFKB and NFAT, T cell activation, and apoptosis are induced. The effects of TBTO on genes involved in ER stress, NFAT pathway, T cell activation and apoptosis were confirmed by qRT-PCR. Activation and nuclear translocation of NFATC1 and the oxidative stress response proteins NRF2 and KEAP1 were confirmed by immunocytology. Taking advantage of previously published microarray data, we demonstrated that the induction of ER stress, oxidative stress, T cell activation and apoptosis by TBTO is not unique for Jurkat cells but does also occur in mouse thymocytes both ex vivo and in vivo and rat thymocytes ex vivo. We propose that the induction of ER stress leading to a T cell activation response is a major factor in the higher sensitivity of immune cells above other types of cells for TBTO. - Research Highlights: → The human T lymphocyte cell line Jurkat was exposed to TBTO. → Whole-genome microarray experiments were performed. → Data analysis revealed the induction of ER stress and activation of NFAT and NFKB. → Exposure to TBTO also led to T cell activation, oxidative stress and apoptosis.

L-carnitine is an endogenous HDAC inhibitor selectively inhibiting cancer cell growth in vivo and in vitro.

Science.gov (United States)

Huang, Hongbiao; Liu, Ningning; Guo, Haiping; Liao, Siyan; Li, Xiaofen; Yang, Changshan; Liu, Shouting; Song, Wenbin; Liu, Chunjiao; Guan, Lixia; Li, Bing; Xu, Li; Zhang, Change; Wang, Xuejun; Dou, Q Ping; Liu, Jinbao

2012-01-01

L-carnitine (LC) is generally believed to transport long-chain acyl groups from fatty acids into the mitochondrial matrix for ATP generation via the citric acid cycle. Based on Warburg's theory that most cancer cells mainly depend on glycolysis for ATP generation, we hypothesize that, LC treatment would lead to disturbance of cellular metabolism and cytotoxicity in cancer cells. In this study, Human hepatoma HepG2, SMMC-7721 cell lines, primary cultured thymocytes and mice bearing HepG2 tumor were used. ATP content was detected by HPLC assay. Cell cycle, cell death and cell viability were assayed by flow cytometry and MTS respectively. Gene, mRNA expression and protein level were detected by gene microarray, Real-time PCR and Western blot respectively. HDAC activities and histone acetylation were detected both in test tube and in cultured cells. A molecular docking study was carried out with CDOCKER protocol of Discovery Studio 2.0 to predict the molecular interaction between L-carnitine and HDAC. Here we found that (1) LC treatment selectively inhibited cancer cell growth in vivo and in vitro; (2) LC treatment selectively induces the expression of p21(cip1) gene, mRNA and protein in cancer cells but not p27(kip1); (4) LC increases histone acetylation and induces accumulation of acetylated histones both in normal thymocytes and cancer cells; (5) LC directly inhibits HDAC I/II activities via binding to the active sites of HDAC and induces histone acetylation and lysine-acetylation accumulation in vitro; (6) LC treatment induces accumulation of acetylated histones in chromatin associated with the p21(cip1) gene but not p27(kip1) detected by ChIP assay. These data support that LC, besides transporting acyl group, works as an endogenous HDAC inhibitor in the cell, which would be of physiological and pathological importance.

Total glucosides of paeony inhibit the inflammatory responses of mice with allergic contact dermatitis by restoring the balanced secretion of pro-/anti-inflammatory cytokines.

Science.gov (United States)

Wang, Chun; Yuan, Jun; Wu, Hua-Xun; Chang, Yan; Wang, Qing-Tong; Wu, Yu-Jing; Zhou, Peng; Yang, Xiao-Dan; Yu, Jun; Wei, Wei

2015-02-01

The present study aimed to investigate the regulation exerted by the total glucosides of paeony (TGP) on the production of interleukin-2 (IL-2), IL-4, IL-10 and IL-17 in the serum and lymphocytes of mice with allergic contact dermatitis (ACD). ACD in mice was induced by the repeated application of 2,4-dinitrochlorobenzene (DNCB) to their skins. The mice were orally administered TGP (35, 70, and 140mg/kg/d) and prednisone (Pre, 5mg/kg/d) from day 1 to day 7 after immunization. The inflammatory responses were evaluated by ear swelling and histological examination. Thymocyte proliferation was assayed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H tetrazolium bromide assay. The cytokine production in the serum and lymphocytes supernatant was measured by enzyme-linked immunosorbent assay. The results indicated that the topical application of DNCB to the skin provoked obvious inflammatory responses. The oral administration of TGP (70 and 140mg/kg/d) and Pre (5mg/kg/d) significantly inhibited skin inflammation, decreased the thymus and spleen indices, and inhibited thymocyte proliferation in mice treated with DNCB. Further study indicated that TGP increased IL-4 and IL-10 production but decreased the production of IL-2 and IL-17 in the serum and lymphocyte supernatant. The correlation analysis suggested significantly positive correlations between IL-2 and IL-17 production and the severity of skin inflammation, whereas negative correlations were obtained for IL-4 and IL-10 production and skin inflammation. In summary, these results suggest that the therapeutic effects of TGP on ACD may result from its regulation of the imbalanced secretion of IL-2/IL-4 and IL-10/IL-17. Copyright © 2014 Elsevier B.V. All rights reserved.

An enhanced postnatal autoimmune profile in 24 week-old C57BL/6 mice developmentally exposed to TCDD

International Nuclear Information System (INIS)

Mustafa, A.; Holladay, S.D.; Goff, M.; Witonsky, S.G.; Kerr, R.; Reilly, C.M.; Sponenberg, D.P.; Gogal, R.M.

2008-01-01

Developmental exposure of mice to the environmental contaminant and AhR agonist, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), causes persistent postnatal suppression of T cell-mediated immune responses. The extent to which prenatal TCDD may induce or exacerbate postnatal autoimmune disease remains unknown. In the present study, time-pregnant high affinity AhR C57BL/6 mice received a single oral administration of 0, 2.5, or 5 μg/kg TCDD on gestation day (gd) 12. Offspring of these mice (n = 5/gender/treatment) were evaluated at 24 weeks-of-age and showed considerable immune dysregulation that was often gender-specific. Decreased thymic weight and percentages of CD4 + CD8 + thymocytes, and increased CD4 + CD8 - thymocytes, were present in the female but not male offspring. Males but not females showed decreased CD4 - CD8 + T cells, and increased Vβ3 + and Vβ17a + T cells, in the spleen. Males but not females also showed increased percentages of bone marrow CD24 - B220 + B cell progenitors. Antibody titers to dsDNA, ssDNA and cardiolipin displayed increasing trends in both male and female mice, reaching significance for anti-dsDNA in both genders and for ssDNA in males at 5 μg/kg TCDD. Immunofluorescent staining of IgG and C3 deposition in kidney glomeruli increased in both genders of prenatal TCDD-exposed mice, suggestive of early stages of autoimmune glomerulonephritis. Collectively, these results show that exposure to TCDD during immune system development causes persistent humoral immune dysregulation as well as altered cell-mediated responses, and induces an adult profile of changes suggestive of increased risk for autoimmune disease

Changes in T cell populations due to local irradiation of a portion of the maxilla in mice

International Nuclear Information System (INIS)

Satoh, Daigo

1997-01-01

The aim of this study was to investigate the changes in the immune organs after head and neck irradiation. The numbers of lymphocytes in peripheral blood, the spleen and the thymus following local irradiation of a portion of the maxilla in mice were studied using three-color fluorometry and were compared with a non-irradiation group. In the peripheral blood, the absolute numbers of T cells, CD4 + SP cells and CD8 + SP cells decreased after irradiation, and the period of the decrease was longer than the decreases in number of leukocytes and lymphocytes. The ratio of CD4 + SP cells showed a significant decrease, and the ratio of CD8+ S P cells showed a significant increase 1 day after irradiation. In the spleen, the absolute number of T cells, the radio of CD4 + SP and CD8 + SP cell subsets showed a decrease, and the period of the decrease was longer than the decrease of the wet-weight of the spleen, and also longer than the decrease of the number of leukocytes. The number of CD4 + SP cells showed a signigicant increase, and CD8 + SP cells showed a significant decrease 21 days after irradiation. In the thymus, the absolute number of TCR αβ-thymocytes did not show a significant decrease. However, the number of DN thymocytes showed a marked decrease. These results indicate that the numbers of T cells in peripheral blood, the spleen and the thymus change immediately after irradiation, and the numbers of lymphocytes and the T cells in the spleen recover more slowly than that in the peripheral blood. As lymphoid tissues showed the suppression of immunological response for a long period, it was suggested that lymphoid tissues have to be observed carefully after irradiation to prevent cancer metastasis. (K.H.)

Thymus-directed immunotoxicity of airborne dust particles from Upper Silesia (Poland) under acute extrapulmonary studies in mice

Energy Technology Data Exchange (ETDEWEB)

Kozlowska, E. [Warsaw Univ. (Poland); Krzystniak, K. [Universite du Quebec a Montreal, Quebec (Canada); Drela, N. [Warsaw Univ. (Poland)] [and others

1996-12-27

Industrial air pollutants from Upper Silesia, Poland, contain over 250 polycyclic and heterocyclic aromatic hydrocarbons and heavy metals, including mutagenic and carcinogenic chemicals that have been shown to from DNA adducts. Over 4 million habitants of Silesia are permanently exposed to the industrial pollution by pulmonary and dermal routes and by contaminated food and water. These chemicals, when examined separately in animals models, were proven immunotoxic. We studied the extrapulmonary immunotoxic potential of a typical mixture of Silesian filter-suspended matter from a selected area, over a specific season and time period. Early changes in the immune system were analyzed in BALB/c mice exposed ip to acute doses of 20-330 mg dust mixture/kg body weight (0.06-1.0 LD50). No major changes were noted for weight and the cellularity of spleen, liver and kidneys. However, dramatic decrease in thymus weight index and thymocyte cell count were noted as early as 24-72 h postexposure, which correlated with almost complete depletion of immature, double-positive CD4{sup +}CD8{sup +} thymocytes. Changes in spleen were less profound; however, increased depletion of B cells over T cells was noted at high doses of the suspended matter. Exposure to the airborne dust also decreased cytokine production by spleen cells, such as interferon-{gamma} (IFN-{gamma}) and tumor necrosis factor-{alpha} (TNF-{alpha}). Overall, a single exposure to Silesian dust, even at the relatively low 0.06 LD50 dose, affected lymphokine production, suppressed B-cell proliferative response, and depleted thymuses of immature, double-positive CD4{sup +}CD8{sup +} cells. A chemical synergism is suspected. To our knowledge, none of the known components of Silesian suspended matter, when examined as a single chemical, was shown to exert such a profound biological effect. 32 refs., 5 figs.

Protective specific immunity induced by cyclophosphamide plus tumor necrosis factor alpha combination treatment of EL4-lymphoma-bearing C57BL/6 mice.

Science.gov (United States)

Krawczyk, C M; Verstovsek, S; Ujházy, P; Maccubbin, D; Ehrke, M J

1995-06-01

A combination treatment protocol initiated 12 days after tumor injection, when the tumor was large, by administering cyclophosphamide (CY, 150 or 250 mg/kg) intraperitoneally followed by intravenous tumor necrosis factor alpha (TNF alpha, 1000 units injection) on days 13, 16, 18, 21, and 23, resulted in about 60% long-term survival (i.e., survival for at least 60 days) in the syngeneic C57BL/6 mouse/EL4 lymphoma model system. The establishment of a specific antitumor immune memory and its possible therapeutic relevance was verified by reinjecting 60-day survivors with EL4 cells; all 60-day survivors that had received the combination treatments rejected the implants and survived for a further 60 days. Thymic cellularity was reduced during treatment and its recovery appeared to correlate with long-term survival and immunity. Thymocytes from mice treated with the combination were found to express significant levels of specific anti-EL4 cytolytic activity following a 4-day stimulation culture with X-irradiated EL4 cells and low concentrations of interleukin-2. This response could not be generated with thymocytes from naive animals. In each case the effect seen with the combination of a moderate CY dose (150 mg/kg) with TNF alpha was better than that seen with either dose of CY alone and equal to or better than that seen with the higher dose of CY combined with TNF alpha. These results indicate that treatment with a single moderate dose of CY in combination with TNF alpha is effective against a large, established tumor in this murine model. Furthermore, all the long-term survivors induced by this treatment developed protective immunity against reimplanted tumor and demonstrated a long-term specific immune memory in the thymus.

In vivo targeting of dead tumor cells in a murine tumor model using a monoclonal antibody specific for the La autoantigen.

Science.gov (United States)

Al-Ejeh, Fares; Darby, Jocelyn M; Pensa, Katherine; Diener, Kerrilyn R; Hayball, John D; Brown, Michael P

2007-09-15

To investigate the potential of the La-specific monoclonal antibody (mAb) 3B9 as an in vivo tumor-targeting agent. The murine EL4 lymphoma cell line was used for in vitro studies and the EL4 model in which apoptosis was induced with cyclophosphamide and etoposide was used for in vivo studies. In vitro studies compared 3B9 binding in the EL4 cell with that in its counterpart primary cell type of the thymocyte. For in vivo studies, 3B9 was intrinsically or extrinsically labeled with carbon-14 or 1,4,7,10-tetra-azacylododecane-N,N',N'',N''''-tetraacetic acid-indium-111, respectively, and biodistribution of the radiotracers was investigated in EL4 tumor-bearing mice, which were treated or not with chemotherapy. La-specific 3B9 mAb bound EL4 cells rather than thymocytes, and binding was detergent resistant. 3B9 binding to dead EL4 cells in vitro was specific, rapid, and saturable. Significantly, more 3B9 bound dead EL4 tumor explant cells after host mice were treated with chemotherapy, which suggested that DNA damage induced 3B9 binding. Tumor binding of 3B9 in vivo was antigen specific and increased significantly after chemotherapy. Tumor accumulation of 3B9 peaked at approximately 50% of the injected dose per gram of tumor 72 h after chemotherapy and correlated with increased tumor cell death. Tumor/organ ratios of 3B9 biodistribution, which included the tumor/blood ratio, exceeded unity 48 or more hours after chemotherapy. La-specific mAb selectively targeted dead tumor cells in vivo, and targeting was augmented by cytotoxic chemotherapy. This novel cell death radioligand may be useful both for radioimmunoscintigraphy and radioimmunotherapy.

CD150 is a member of a family of genes that encode glycoproteins on the surface of hematopoietic cells.

Science.gov (United States)

Wang, N; Morra, M; Wu, C; Gullo, C; Howie, D; Coyle, T; Engel, P; Terhorst, C

2001-07-01

Human CD150 (SLAM) is a glycoprotein expressed on the surface of T, B, natural killer, and dendritic cells. The extracellular domain of CD150 is the receptor for measles virus and CD150 acts as a co-activator on T and B cells. We characterized the mouse and human CD150 genes, each of which comprises seven exons spanning approximately 32 kb. Mouse CD150 mRNA was detected in T cells and in most thymocyte subsets, except CD4-8- cells. Surprisingly, the CD4-8- thymocytes of CD3gammadeltanull mice, but not of Ragnull or severe combined immunodeficiency mice, expressed CD150. Whereas high levels of CD150 were found in Th1 cells, only small amounts were detectable in Th2 cells. CD150 expression was up-regulated upon in vitro activation of mouse T cells by anti-CD3. The complete mouse CD150 gene is highly homologous to its human orthologue in terms of nucleotide sequences and intron/exon organization. The human genomic sequences indicate that all isoforms detected so far have arisen from alternative splicing events. As judged by fluorescence in situ hybridization, mouse CD150 mapped to Chromosome (Chr) 1, band 1H2.2-2.3, and human CD150 was found on Chr 1q22. Human and mouse CD150 share sequence homologies with six other genes, five of which - CD84, CD229 (Ly-9), CD244 (2B4), CD48, and 19A - are localized in a 250-kb segment in close proximity to the human gene. Their location and their sequence similarities strongly suggest that the CD150 family of cell surface receptors arose via successive duplications of a common ancestral gene.

Confusion and Agitation after a Recent Kidney Transplantation

Directory of Open Access Journals (Sweden)

Hussein Magdi

2008-01-01

Full Text Available A 51-year-old man, who received a living related transplant from his wife and anti-thymocyte globulin (ATG as induction therapy, developed delayed graft function after transplantation. One day after he received an i.v. dose of ganciclovir, the patient developed hallucinations, confusion and agitation, which worsened the following day. CT-scan of the brain and cerebrospinal fluid were unremarkable. Ganciclovir-induced encepha-lopathy was considered the most likely reason for the patient′s neurological condition, since he recovered completely a few days after discontinuation of this drug. Since anti-CMV prophylactic treatment is now widely used after transplantation, a high index of suspicion is required to diagnose ganciclovir (or acyclovir induced neurotoxicity.

Influence of a radioprotector WR-638 on the lymphoid compartment of the irradiated rat thymus: a flow cytometric analysis

International Nuclear Information System (INIS)

Dragojevic-Simic, V.; Colic, M.; Gasic, S.

1994-01-01

The T cell composition of the thymus of X-ray irradiated (3.5 Gy) Wistar rat protected with WR-638 was analyzed by flow cytometry using monoclonal antibodies directed to the Thy 1.1, CD43, CD2, CD5, CD4, CD8 and class I and II MHC antigens. It was shown that this dose of X-rays caused cyclic changes in thymic cellularity manifested as: primary involution (until day 2), primary regeneration (from days 2 to 14), secondary involution (from days 14 to 21) and secondary regeneration (from days 21 to 30). WR-638 reduced the magnitude of thymocyte depletion in the primary involutive phase of the irradiated thymi. (author)

Preparation and in vitro evaluation of human recombinant annexin V using for apoptosis

International Nuclear Information System (INIS)

Chen Daming; Beijing Univ., Beijing; Qi Benzhong; Yang Hongwei; Luo Zhifu; Zhang Jinrong; Jin Xiaohai; Jia Bing; Xie Hong; Ma Dalong

2004-01-01

Human recombinant Annexin V was produced by expression in E coli with high efficiency through genetic engineering. The technique procedure concerned in the temperature and time of vector expression, the basic routine and purification of proteins was established in order to obtain a large quantity of Annexin V. the results of SDS-PAGE analysis and the apoptosis detection of single cell of thymocytes of Balb/c mice using FITC-Annexin V caused by dexamethasone with availableness show that the mature Annexin V with high purity and biologic activity is obtained by ion exchange chromatography. The results of cell binding assay show that its KD is 8.53 nmol/mL and RT is 8.79 nmol/mL. (authors)

Analysis of interleukin 1 mediated radioprotection

International Nuclear Information System (INIS)

Manori, I.; Kushilevsky, A.; Weinstein, Y.

1986-01-01

The potential value of interleukin 1(IL-1) containing supernatants as a radioprotective agent was evaluated. It was found that the response of irradiated thymocytes to mitogens was partially restored if IL-1 containing supernatants was included in the culture medium immediately after irradiation. A delay of 24 h in the addition of IL-1 and mitogen abrogated the radioprotection effect. Under the same conditions IL-2 containing supernatants were effective, suggesting that the dose modifying effect of IL-1 acts through induction of IL-2 elaboration. The results of the present study may be important in cases where it is necessary to restore depressed immune response resulting from irradiation accidents or radiotherapy. (author)

A role for E2-2 at the DN3 stage of early thymopoiesis

DEFF Research Database (Denmark)

Wikström, Ingela; Forssell, Johan; Penha-Goncalves, Mario N

2008-01-01

Roles for the E-proteins E2A and HEB during T lymphocyte development have been well established. Based on our previous observations of counter selection against T cells lacking E2-2, it seemed reasonable to assume that there would be a function also for E2-2 in thymocyte development. Aiming...... proteins, Id2 displayed a prominent expression exclusively in DN1, whereas Id3 showed some expression in DN1, followed by a down regulation and then a prominent induction, peaking in the DP stage. E2-2 was expressed during the DN stages, as well as in the DP stage, suggesting that E2-2 operates in concert...

The Study of Non-Linear Acceleration of Particles during Substorms Using Multi-Scale Simulations

International Nuclear Information System (INIS)

Ashour-Abdalla, Maha

2011-01-01

To understand particle acceleration during magnetospheric substorms we must consider the problem on multple scales ranging from the large scale changes in the entire magnetosphere to the microphysics of wave particle interactions. In this paper we present two examples that demonstrate the complexity of substorm particle acceleration and its multi-scale nature. The first substorm provided us with an excellent example of ion acceleration. On March 1, 2008 four THEMIS spacecraft were in a line extending from 8 R E to 23 R E in the magnetotail during a very large substorm during which ions were accelerated to >500 keV. We used a combination of a global magnetohydrodynamic and large scale kinetic simulations to model the ion acceleration and found that the ions gained energy by non-adiabatic trajectories across the substorm electric field in a narrow region extending across the magnetotail between x = -10 R E and x = -15 R E . In this strip called the 'wall region' the ions move rapidly in azimuth and gain 100s of keV. In the second example we studied the acceleration of electrons associated with a pair of dipolarization fronts during a substorm on February 15, 2008. During this substorm three THEMIS spacecraft were grouped in the near-Earth magnetotail (x ∼-10 R E ) and observed electron acceleration of >100 keV accompanied by intense plasma waves. We used the MHD simulations and analytic theory to show that adiabatic motion (betatron and Fermi acceleration) was insufficient to account for the electron acceleration and that kinetic processes associated with the plasma waves were important.

PROPAGATING WAVES TRANSVERSE TO THE MAGNETIC FIELD IN A SOLAR PROMINENCE

Energy Technology Data Exchange (ETDEWEB)

Schmieder, B. [Observatoire de Paris, LESIA, UMR 8109 (CNRS), F-92195 Meudon (France); Kucera, T. A.; Knizhnik, K. [Code 671, NASA' s GSFC, Greenbelt, MD 20771 (United States); Luna, M. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Lopez-Ariste, A. [THEMIS, CNRS-UPS853, E-38205 La Laguna (Spain); Toot, D. [Alfred University, Alfred, NY 14802 (United States)

2013-11-10

We report an unusual set of observations of waves in a large prominence pillar that consist of pulses propagating perpendicular to the prominence magnetic field. We observe a huge quiescent prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly in EUV on 2012 October 10 and only a part of it, the pillar, which is a foot or barb of the prominence, with the Hinode Solar Optical Telescope (SOT; in Ca II and Hα lines), Sac Peak (in Hα, Hβ, and Na-D lines), and THEMIS ({sup T}élescope Héliographique pour l' Etude du Magnétisme et des Instabilités Solaires{sup )} with the MTR (MulTi-Raies) spectropolarimeter (in He D{sub 3} line). The THEMIS/MTR data indicates that the magnetic field in the pillar is essentially horizontal and the observations in the optical domain show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data over the four hour observing period show vertical oscillations appearing as wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along thin quasi-vertical columns in the much broader pillar. The pulses have a velocity of propagation of about 10 km s{sup –1}, a period of about 300 s, and a wavelength around 2000 km. We interpret these waves in terms of fast magnetosonic waves and discuss possible wave drivers.

Simultaneous Measurements of Substorm-Related Electron Energization in the Ionosphere and the Plasma Sheet

Science.gov (United States)

Sivadas, N.; Semeter, J.; Nishimura, Y.; Kero, A.

2017-10-01

On 26 March 2008, simultaneous measurements of a large substorm were made using the Poker Flat Incoherent Scatter Radar, Time History of Events and Macroscale Interactions during Substorm (THEMIS) spacecraft, and all sky cameras. After the onset, electron precipitation reached energies ≳100 keV leading to intense D region ionization. Identifying the source of energetic precipitation has been a challenge because of lack of quantitative and magnetically conjugate measurements of loss cone electrons. In this study, we use the maximum entropy inversion technique to invert altitude profiles of ionization measured by the radar to estimate the loss cone energy spectra of primary electrons. By comparing them with magnetically conjugate measurements from THEMIS-D spacecraft in the nightside plasma sheet, we constrain the source location and acceleration mechanism of precipitating electrons of different energy ranges. Our analysis suggests that the observed electrons ≳100 keV are a result of pitch angle scattering of electrons originating from or tailward of the inner plasma sheet at 9RE, possibly through interaction with electromagnetic ion cyclotron waves. The electrons of energy 10-100 keV are produced by pitch angle scattering due to a potential drop of ≲10 kV in the auroral acceleration region (AAR) as well as wave-particle interactions in and tailward of the AAR. This work demonstrates the utility of magnetically conjugate ground- and space-based measurements in constraining the source of energetic electron precipitation. Unlike in situ spacecraft measurements, ground-based incoherent scatter radars combined with an appropriate inversion technique can be used to provide remote and continuous-time estimates of loss cone electrons in the plasma sheet.

Human HMGA2 protein overexpressed in mice induces precursor T-cell lymphoblastic leukemia

International Nuclear Information System (INIS)

Efanov, A; Zanesi, N; Coppola, V; Nuovo, G; Bolon, B; Wernicle-Jameson, D; Lagana, A; Hansjuerg, A; Pichiorri, F; Croce, C M

2014-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a neoplasia of thymocytes characterized by the rapid accumulation of the precursors of T lymphocytes. HMGA2 (high-mobility group AT-hook 2) gene expression is extremely low in normal adult tissues, but it is overexpressed in many tumors. To identify the biological function of HMGA2, we generated transgenic mice carrying the human HMGA2 gene under control of the V H promoter/Eμ enhancer. Approximately 90% of Eμ-HMGA2 transgenic mice became visibly sick between 4 and 8 months due to the onset and progression of a T-ALL-like disease. Characteristic features included severe alopecia (30% of mice); enlarged lymph nodes and spleen; and profound immunological abnormalities (altered cytokine levels, hypoimmunoglobulinemia) leading to reduced immune responsiveness. Immunophenotyping showed accumulation of CD5+CD4+, CD5+CD8+ or CD5+CD8+CD4+ T-cell populations in the spleens and bone marrow of sick animals. These findings show that HMGA2-driven leukemia in mice closely resembles spontaneous human T-ALL, indicating that HMGA2 transgenic mice should serve as an important model for investigating basic mechanisms and potential new therapies of relevance to human T-ALL

Control rod position control device

International Nuclear Information System (INIS)

Ubukata, Shinji.

1997-01-01

The present invention provides a control rod position control device which stores data such as of position signals and driving control rod instruction before and after occurrence of abnormality in control for the control rod position for controlling reactor power and utilized the data effectively for investigating the cause of abnormality. Namely, a plurality of individual control devices have an operation mismatching detection circuit for outputting signals when difference is caused between a driving instruction given to the control rod position control device and the control rod driving means and signals from a detection means for detecting an actual moving amount. A general control device collectively controls the individual control devices. In addition, there is also disposed a position storing circuit for storing position signals at least before and after the occurrence of the control rod operation mismatching. With such procedures, the cause of the abnormality can be determined based on the position signals before and after the occurrence of control rod mismatching operation stored in the position storing circuit. Accordingly, the abnormality cause can be determined to conduct restoration in an early stage. (I.S.)

Stationary stochastic processes for scientists and engineers

CERN Document Server

Lindgren, Georg; Sandsten, Maria

2013-01-01

""This book is designed for a first course in stationary stochastic processes in science and engineering and does a very good job in introducing many concepts and ideas to students in these fields. … the book has probably been tested in the classroom many times, which also manifests itself in its virtual lack of typos. … Another great feature of the book is that it contains a wealth of worked example from many different fields. These help clarify concepts and theorems and I believe students will appreciate them-I certainly did. … The book is well suited for a one-semester course as it contains

Characteristics of ion distribution functions in dipolarizing flux bundles: Event studies

Science.gov (United States)

Runov, A.; Angelopoulos, V.; Artemyev, A.; Birn, J.; Pritchett, P. L.; Zhou, X.-Z.

2017-06-01

Taking advantage of multipoint observations from a repeating configuration of the five Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes separated by 1 to 2 Earth radii (RE) along X, Y, and Z in the geocentric solar magnetospheric system (GSM), we study ion distribution functions collected by the probes during three dipolarizing flux bundle (DFB) events observed at geocentric distances 9 energy and twice the thermal energy, although the distribution in the ambient plasma sheet was isotropic. The anisotropic ion distribution in DFBs injected toward the inner magnetosphere may provide the free energy for waves and instabilities, which are important elements of particle energization.

Petri Net Approach of Collision Prevention Supervisor Design in Port Transport System

Directory of Open Access Journals (Sweden)

Danko Kezić

2007-09-01

Full Text Available Modern port terminals are equipped with various localtransport systems, which have the main task to transport cargobetween local storehouses and transport resources (ships,trains, trucks in the fastest and most efficient way, and at thelowest possible cost. These local transport systems consist offully automated transport units (AGV- automatic guided vehiclewhich are controlled by the computer system. The portcomputer system controls the fully automated transport units inthe way to avoid possible deadlocks and collisions betweenthem. However, beside the fully automated local transportunits, there are human operated transport units (fork-lifttrucks, cranes etc. which cross the path oftheAGVfrom timeto time. The collision of human operated transp011 unit andA GV is possible due to human inattention. To solve this problem,it is necesswy to design a supe1vismy control system thatcoordinates and controls both human driven transport unit andA G V In other words, the human-machine interactions need tobe supen·ised. The supen•ising system can be realized in the waythat the port terminal is divided into zones. Vehicle movementsare supen•ised by a video system which detects the moving ofparticular l'ehicles as a discrete event. Based on detected events,dangerous moving of certain vehicles is blocked by the supe1visi11gsystem. The paper considers the design of collision preventionsupen•isor by using discrete event dynamic themy. The portterminal is modeled by using ordi1za1y Petri nets. The design ofcollision prevention supe1visor is cmTied out by using the P-inl'ariantmethod. The verification of the supervisor is done bycomputer simulation.

Polybrominated Diphenyl Ethers Orally Administration to Mice Were Tansferred to Offspring during Gestation and Lactation with Disruptions on the Immune System.

Science.gov (United States)

Hong, Soon Keun; Sohn, Kyung Hee; Kim, In Young; Lee, Jong Kwon; Ju, Jung Hun; Kim, Jin Ho; Lim, Chae Hyung; Han, Beom Seok; Jung, Hwa Chul; Lee, Jin Yong; Park, Kui Lea

2010-04-01

The present study was undertaken to examine the immunological effects of pentabrominated diphenyl ether (penta-BDE) and decabrominated diphenyl ether (deca-BDE) on the immune system of the dams and the developmental immune system of the offsprings. In this study, mated female C57BL/6J mice were orally administered penta-BDE, deca-BDE or corn oil for 5 weeks, from gestational day 6 to lactational day 21. The body weight of PND21 exposed to penta-BDE was significantly decreased relative to control mice, but that of post-natal day 63 (PND63) were recovered. Orally dosed dams with penta-BDE had significantly smaller absolute and relative spleen masses than control mice. Absolute and relative spleen and thymus masses of PND21 exposed to penta-BDE were significantly decreased over control. The exposure of dams and PND21 with penta-BDE reduced the number of splenocytes and thymocytes. As results of hematologic analysis, percentage WBC and percentage neutrophils increased in dams with deca-BDE. Splenic T cell proliferation in dams and PND21 exposed to penta-BDE was increased, and there were no significant difference in splenic B cell proliferation in all treatment groups. As results of flow cytometric analysis of splenocyte, percentage total T cell, Th cell and Tc cell in PND21 exposed to penta-BDE was slightly increased, and percentage macrophage in dams and PND21 exposed to deca-BDE was decreased. The ELISA results of antibody production show no significant difference in all treatment groups relative to controls. These results imply that PBDEs given to the dam were transferred to the offspring during gestation and lactation, and PBDEs transferred from the dam affect immune system of offspring.

Interaction involving the thymus and the hypothalamus-pituitary axis, immunomodulation by hormones

Directory of Open Access Journals (Sweden)

Marković Ljiljana 2

2004-01-01

metabolism through regulating osteoprotegerin (OPG production, the estrogen is involved in the processes of thymocyte development although aromatase mRNA has not been detectable in the thymus. While the increase of TNC number during lactation may be linked to the process of reconstruction of the thymic lymphoid population, the increased activity of lymphoepithelial interactions on GD14 may be associated with thymic engagement in pregnancy-induced immune processes [27,29] The major antigens in the experimental autoimmune hypophysitis in rats are growth hormone, thyrotropin, and luteinizing hormone [12]. The intrathymic T-lymphocyte selection is a complex, multistep process, influenced by several functionally specialised RE cells and under immuno-neuroendocrine regulation control reflecting the dynamic changes of the mammalian organism. In HIV-1-infected adults treated with growth hormone [25 ], thymic mass and circulating naive CD4 T cells are increased. The treatment would be easier for the diseased, as well as to us, the physicians, if we were aware of two millennia old wisdom - that the disease is a visit of God.

Spectroscopic diagnostics of an H alpha and EUV filament observed with THEMIS and SOHO

Czech Academy of Sciences Publication Activity Database

Schmieder, B.; Tziotziou, K.; Heinzel, Petr

2003-01-01

Roč. 401, č. 1 (2003), s. 361-375 ISSN 0004-6361 R&D Projects: GA AV ČR IAA3003203; GA AV ČR IBS1003006 Institutional research plan: CEZ:AV0Z1003909 Keywords : filaments * line profiles * radiative transfer Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.843, year: 2003