Search

22nd Congress of the European-Hematology-Association, Madrid, SPAIN, JUN 22-25, 2017; International audience

International audience; Type II diabetes is a serious, insidious disease which is growing at an impressive rate, with 200 million diabetics worldwide and as many who ignore their state. Having been seriously studied over more than a century and a half, an enormous quantity of knowledge regarding this disease has been accumulated. The research we are conducting has allowed us to identify the most important actors responsible for diabetes. These are glucose which leads to glyoxal and to methylglyoxal which in turn reacts with innumerable targets in the organism (including insulin) unless prevented from doing so by detoxifying mechanisms (e.g., glyoxalases). The role of microorganisms in the occurrence and development of diabetes has also to be seriously examined.

International audience

The tetrapeptide Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP), an inhibitor of hematopoietic stem cell proliferation, is known to reduce in vivo the damage resulting from treatment with chemotherapeutic agents or ionizing radiation on the stem cell compartment, Recently, AcSDKP has been shown to be a physiological substrate of the N-active site of angiotensin I-converting enzyme (ACE), Four analogs of the tetrapeptide expressing a high stability towards ACE degradation in vitro have been synthesized in order to provide new molecules likely to improve the myeloprotection displayed by AcSDKP, These analogs are three pseudopeptides with a modified peptidic bond, Ac-Ser Psi(CH(2)-NH)Asp-Lys-Pro, Ac-Ser-Asp-Psi(CH(2)-NH)Lys-Pro, Ac-Ser-Asp-Lys Psi(CH(2)-N)Pro, and one C-terminus modified peptide (AcSDKP-NH(2)), We report here that these analogs reduce in vitro the proportion of murine colony-forming units-granulocyte/macrophage in S-phase and inhibit the entry into cycle of high proliferative potential colony-forming cells, The efficacy of AcSDKP analogs in preventing in vitro primitive hematopoietic stem cells from entering into cycle suggests that these molecules could be new candidates for the powerful inhibition of hematopoietic stem and progenitor cell proliferation in vivo.

International audience; The tetrapeptide Acetyl-N-Ser-Asp-Lys-Pro (AcSDKP or Goralatide), a physiological regulator of hematopoiesis, inhibits the entry into the S-phase of murine and human hematopoietic stem cells. It has been shown to reduce the damage to specific compartments in the bone marrow resulting from treatment with chemotherapeutic agents, ionizing radiations, hyperthermy, or phototherapy. The present study was performed to assess the therapeutic potential of AcSDKP in vivo in reducing both the toxicity and the hematopoietic damage induced by fractionated administration of doxorubicin (DOX), a widely used anticancer drug. Here we showed that AcSDKP could reduce DOX-induced mortality in mice and could protect particularly the long-term reconstituting cells (LTRCs) in addition to colony forming units-spleen, high proliferative potential colony-forming cells, and colony-forming units-granulocyte-macrophage (CFU-GM) from DOX toxicity. The protection against DOX-induced mortality in mice was improved when AcSDKP was administered for 3 days, at a dose of 2.4 micrograms/d, by continuous subcutaneous (SC) infusion or fractionated s.c. injections starting 48 hours before DOX treatment. Moreover, the recovery of the CFU-GM population in the AcSDKP-DOX-treated mice was optimized by the subsequent administration of granulocyte colony-stimulating factor (G-CSF). The coadministration of AcSDKP with DOX may improve its therapeutic index by reducing both acute hematotoxicity on late stem cells and progenitors and long-term toxicity on LTRCs. Optimization of these treatments combined with G-CSF may provide an additional approach to facilitate hematopoietic recovery after cancer chemotherapy.

Au Cameroun, la pourriture brune des cabosses du cacaoyer due à Phytophthora spp. est responsable d'importantes chutes de production, jusqu'à 80 % de pertes lors d'années favorables au développement de l'épidémie. Le coût d'une protection phytosanitaire réduisant trop le revenu des paysans, des essais ont été mis en place afin de déterminer l'influence de diverses pratiques culturales sur l'évolution de la maladie au champ : la taille de début de campagne et la récolte sanitaire en début de campagne et hebdomadaire. Une analyse de l'effet de ces pratiques sur le niveau d'infection et la production de cabosses est proposée. Le meilleur résultat a été obtenu avec une taille et une suppression des cabosses momifiées en début de campagne, suivis de récoltes sanitaires hebdomadaires, une diminution du taux d'attaque de 25 % et une production de l'ordre de 700 kg/ha ont ainsi été obtenues. Ces deux techniques culturales mises en place à partir du démarrage de l'épidémie, apparaissent comme étant le schéma minimal. Toutefois, dans le cas de niveaux d'attaque élevés, ces pratiques ne peuvent être envisagées qu'en complément de traitements fongicides, seuls capables de ralentir significativement la progression de la maladie

International audience; The comparative degradation of N-Ac-Ser-Asp-Lys-Pro (AcSDKP), a negative regulator controlling the proliferation of the hematopoietic pluripotent stem cell, was investigated following incubation with plasma, bone marrow and spleen cells from normal mice and mice bearing a transplantable myeloid leukemia. Using the tetrapeptide, specifically radiolabelled in the lysyl residue, degradation of [3H]AcSDKP was followed by measurement of [3H]Lys formation resulting from its catabolism. It was shown that already after 1 h the degradation of AcSDKP in plasma from leukemic mice was higher compared to that following incubation in plasma from normal mice, whereas incubation with bone marrow cells exhibits a small difference only after 4 hours incubation. However, no increase of AcSDKP catabolic activity was observed following incubation with spleen cells from leukemic animals when compared with incubation of normal spleen cells.

La culture axénique de spores d'Hemileia vastatrix a été réalisée sur milieu de Lesovoj et al. Deux types de semis en boîtes de Pétri ou en tubes, maintenus à 23¼C, à l'obscurité pendant 3 jours, puis à la lumière artificielle continue, ont donné des résultats positifs et constants. Après 4 semaines, on observe des cultures (pustules éparses) de 1 à 3 mm de diamètre, de couleur orangée et d'aspect muqueux; la morphologie du mycélium est semblable à celle du mycélium parasite in vivo

En 1983, un groupe de recherches pluridisciplinaires a été constitué sous l'impulsion de la DGRST camerounaise, en collaboration avec l'IRCC et le GERDAT. Un programme a été élaboré et une première étape de 3 ans a été définie. Les principaux résultats obtenus concernent : l'étude de la phase saprophyte du parasite, l'épidémiologie, les tests précoces d'évaluation de la résistance à la maladie, des informations sur la constitution biochimique du cacaoyer et la lutte chimique

Solar Photometer in X-rays (SphinX) was a spectrophotometer developed to observe the Sun in soft X-rays. The instrument observed in the energy range ≈ 1 – 15 keV with resolution ≈ 0.4 keV. SphinX was flown on the Russian CORONAS–PHOTON satellite placed inside the TESIS EUV and X telescope assembly. The spacecraft launch took place on 30 January 2009 at 13:30 UT at the Plesetsk Cosmodrome in Russia. The SphinX experiment mission began a couple of weeks later on 20 February 2009 when the first telemetry dumps were received. The mission ended nine months later on 29 November 2009 when data transmission was terminated. SphinX provided an excellent set of observations during very low solar activity. This was indeed the period in which solar activity dropped to the lowest level observed in X-rays ever. The SphinX instrument design, construction, and operation principle are described. Information on SphinX data repositories, dissemination methods, format, and calibration is given together with general recommendations for data users. Scientific research areas in which SphinX data find application are reviewed.

The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3 and 1.1 x 10^48 cm^-3. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs., Astrophysical Journal, in press. 14 pp, 3 figures

Three of the four detectors of the SphinX experiment to be flown on the Russian mission Coronas-Photon have been measured at the XACT Facility of the Palermo Observatory at several wavelengths in the soft X-ray band. We describe the instrumental set-up and report some measurements. The analysis work to obtain the final calibration is still in progress.