11,551 research outputs found

    CaractĂ©risation physico-chimiques des noix et de l’huile des premiers cocotiers (Cocos nucifera L.) PB 121 issus de la culture in vitro d’embryon zygotique plantĂ©s en CĂŽte d’Ivoire

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    Le prĂ©sent travail vise Ă  Ă©valuer les caractĂ©ristiques physico-chimiques de noix et de l’huile d’amande  des premiers cocotiers PB 121 issus de la culture in vitro. Les observations ont Ă©tĂ© faites sur des noix de troisstades de maturitĂ© puis comparĂ©es avec celles des cocotiers PB 121 plantĂ©s ordinairement (PB 121 O). Il en ressort que les masses des noix PB 121 O sont significativement supĂ©rieures Ă  celles issues de culture in vitro (PB 121 V), pendant que celles d’amande sont moins Ă©levĂ©es. Les teneurs en huiles augmentent gĂ©nĂ©ralement au cours de la maturation jusqu’au rang 25 Ă  70,80% chez PB 121 O et 69,78% chez PB 121 V. Elles baissent ensuite respectivement jusqu’à 65,44% et 64,78%. Les indices d’acide et d’iode sont moins Ă©levĂ©s chez les PB 121 V avec respectivement au rang 24 sont de 5,33 et 33,00% puis 5,89 et 39,98% chez PB 121 O. Les indices de saponification de PB 121 V sont supĂ©rieurs Ă  ceux de PB 121 O. L'acide laurique reprĂ©sente l’acide gras le plus abondant des huiles Ă©tudiĂ©es. L’huile d’amande de PB 121 V qui est plus stable et moins acide est plus appropriĂ©e en savonnerie.Mots clĂ©s : Cocotier, in vitro, amande, huile

    Electron and ion microprobe analysis of calcium distribution and transport in coral tissues.

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    It is shown by x-ray microanalysis that a gradient of total intracellular Ca concentration exists from the outer oral ectoderm to the inner skeletogenic calicoblastic ectoderm in the coral Galaxea fascicularis. This suggests an increase in intracellular Ca stores in relation to calcification. Furthermore, Ca concentration in the fluid-filled space of the extrathecal coelenteron is approximately twice as high as in the surrounding seawater and higher than in the mucus-containing seawater layer on the exterior of the oral ectoderm. This is indicative of active Ca2+ transport across the oral epithelium. Polyps were incubated in artificial seawater in which all 40Ca was replaced by 44Ca. Imaging Ca2+ transport across the epithelia by secondary ion mass spectroscopy (SIMS) using 44Ca as a tracer showed that Ca2+ rapidly entered the cells of the oral epithelium and that 44Ca reached higher concentrations in the mesogloea and extrathecal coelenteron than in the external seawater layer. Very little Ca2+ was exchanged in the mucocytes, cnidocytes or zooxanthellae. These observations again suggest that Ca2+ transport is active and transcellular and also indicate a hitherto unsuspected role in Ca2+ transport for the mesogloea. © 2007, Company of Biologist

    Effects of therapeutic and aerobic exercise programs in temporomandibular disorder-associated headaches

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    Objective: To assess the effects of three 8-week exercise programs on the frequency, intensity, and impact of headaches in patients with headache attributed to temporomandibular disorder (TMD). Methodology: Thirty-six patients diagnosed with headache attributed to TMD participated in the study and were divided into three groups of 12 patients: a therapeutic exercise program (G1, mean age: 26.3±5.6 years), a therapeutic and aerobic exercise program (G2, mean age: 26.0±4.6 years), and an aerobic exercise program (G3, 25.8±2.94 years). Headache frequency and intensity were evaluated using a headache diary, and the adverse headache impact was evaluated using the Headache Impact Test (HIT-6). The intensity was reported using the numerical pain rating scale. These parameters were evaluated twice at baseline (A01/A02), at the end of the 8-week intervention period (A1), and 8-12 weeks after the end of the intervention (A2). Results: At A1, none of the G2 patients reported having headaches, in G1, only two patients reported headaches, and in G3, ten patients reported headache. The headache intensity scores (0.3 [95% CI: -0.401, 1.068]), (0.0 [95% CI: -0.734, 0.734]) and HIT-6 (50.7 [95% CI: 38.008, 63.459]), (49.5 [95% CI: 36.808, 62.259]), significantly decreased in G1 and G2 at A1. At A2 headache intensity scores (0.5 [95% CI: -0.256, 1.256]), (0.0 [95% CI: -0.756, 0.756]) and HIT-6 (55.1 [95% CI: 42.998, 67.268]), (51.7 [95% CI: 39.532, 63.802]) in G1 and G2 haven't change significantly. The effects obtained immediately after the completion of the intervention programs were maintained until the final follow-up in all groups. Conclusion: The programs conducted by G1 (therapeutic exercises) and G2 (therapeutic and aerobic exercise) had significant results at A1 and A2.info:eu-repo/semantics/publishedVersio

    Surfactant status and respiratory outcome in premature infants receiving late surfactant treatment.

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    BACKGROUND:Many premature infants with respiratory failure are deficient in surfactant, but the relationship to occurrence of bronchopulmonary dysplasia (BPD) is uncertain. METHODS:Tracheal aspirates were collected from 209 treated and control infants enrolled at 7-14 days in the Trial of Late Surfactant. The content of phospholipid, surfactant protein B, and total protein were determined in large aggregate (active) surfactant. RESULTS:At 24 h, surfactant treatment transiently increased surfactant protein B content (70%, p < 0.01), but did not affect recovered airway surfactant or total protein/phospholipid. The level of recovered surfactant during dosing was directly associated with content of surfactant protein B (r = 0.50, p < 0.00001) and inversely related to total protein (r = 0.39, p < 0.0001). For all infants, occurrence of BPD was associated with lower levels of recovered large aggregate surfactant, higher protein content, and lower SP-B levels. Tracheal aspirates with lower amounts of recovered surfactant had an increased proportion of small vesicle (inactive) surfactant. CONCLUSIONS:We conclude that many intubated premature infants are deficient in active surfactant, in part due to increased intra-alveolar metabolism, low SP-B content, and protein inhibition, and that the severity of this deficit is predictive of BPD. Late surfactant treatment at the frequency used did not provide a sustained increase in airway surfactant

    An extracellular transglutaminase is required for apple pollen tube growth

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    An extracellular form of the calcium-dependent protein-crosslinking enzyme TGase (transglutaminase) was demonstrated to be involved in the apical growth of Malus domestica pollen tube. Apple pollen TGase and its substrates were co-localized within aggregates on the pollen tube surface, as determined by indirect immunofluorescence staining and the in situ cross-linking of fluorescently labelled substrates. TGase-specific inhibitors and an anti-TGase monoclonal antibody blocked pollen tube growth, whereas incorporation of a recombinant fluorescent mammalian TGase substrate (histidine-tagged green fluorescent protein:His6– Xpr–GFP) into the growing tube wall enhanced tube length and germination, consistent with a role of TGase as a modulator of cell wall building and strengthening. The secreted pollen TGase catalysed the cross-linking of both PAs (polyamines) into proteins (released by the pollen tube) and His6-Xpr-GFP into endogenous or exogenously added substrates. A similar distribution of TGase activitywas observed in planta on pollen tubes germinating inside the style, consistent with a possible additional role for TGase in the interaction between the pollen tube and the style during fertilization

    Clinical spectrum of paradoxical deterioration during antituberculosis therapy in non-HIV-infected patients

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    Paradoxical deterioration during antituberculosis therapy, defined as the clinical or radiological worsening of pre-existing tuberculous lesions or the development of new lesions in a patient who initially improves, remains a diagnostic dilemma. Although different clinical presentations of paradoxical response have been described, a systematic analysis of the entity in non-HIV-infected patients is lacking. Reported here are two cases of paradoxical deterioration in which sequential changes in lymphocyte counts and tuberculin skin test results are emphasized. In addition, 120 episodes of paradoxical response after antituberculosis treatment were reviewed. Of the total 122 episodes, 101 (82.8%) were associated with extrapulmonary tuberculosis. The median time from commencement of treatment to paradoxical deterioration was 60 days. The median time to onset of central nervous system manifestations (63 days) was longer than the time to onset of manifestations at other sites (56 days) (P=0.02). Development of new lesions in anatomical sites other than those observed at initial presentation was observed in 31 (25.4%) episodes. A surge in the lymphocyte count, accompanied by an exaggerated tuberculin skin reaction, was observed in our patients during the paradoxical deterioration, analogous to the findings in HIV-positive patients. Treatment of the paradoxical response included surgical intervention (60.7%) and administration of steroids (39.3%). The use of steroids appeared to be safe in this series, as 95% of the Mycobacterium tuberculosis isolates were susceptible to first-line antituberculosis therapy.postprin

    Synthetic organisms and living machines: Positioning the products of synthetic biology at the borderline between living and non-living matter

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    The difference between a non-living machine such as a vacuum cleaner and a living organism as a lion seems to be obvious. The two types of entities differ in their material consistence, their origin, their development and their purpose. This apparently clear-cut borderline has previously been challenged by fictitious ideas of “artificial organism” and “living machines” as well as by progress in technology and breeding. The emergence of novel technologies such as artificial life, nanobiotechnology and synthetic biology are definitely blurring the boundary between our understanding of living and non-living matter. This essay discusses where, at the borderline between living and non-living matter, we can position the future products of synthetic biology that belong to the two hybrid entities “synthetic organisms” and “living machines” and how the approaching realization of such hybrid entities affects our understanding of organisms and machines. For this purpose we focus on the description of three different types of synthetic biology products and the aims assigned to their realization: (1) synthetic minimal cells aimed at by protocell synthetic biology, (2) chassis organisms strived for by synthetic genomics and (3) genetically engineered machines produced by bioengineering. We argue that in the case of synthetic biology the purpose is more decisive for the categorization of a product as an organism or a machine than its origin and development. This has certain ethical implications because the definition of an entity as machine seems to allow bypassing the discussion about the assignment and evaluation of instrumental and intrinsic values, which can be raised in the case of organisms

    Lectin-Based Food Poisoning: A New Mechanism of Protein Toxicity

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    BACKGROUND: Ingestion of the lectins present in certain improperly cooked vegetables can result in acute GI tract distress, but the mechanism of toxicity is unknown. In vivo, gut epithelial cells are constantly exposed to mechanical and other stresses and consequently individual cells frequently experience plasma membrane disruptions. Repair of these cell surface disruptions allows the wounded cell to survive: failure results in necrotic cell death. Plasma membrane repair is mediated, in part, by an exocytotic event that adds a patch of internal membrane to the defect site. Lectins are known to inhibit exocytosis. We therefore tested the novel hypothesis that lectin toxicity is due to an inhibitory effect on plasma membrane repair. METHODS AND FINDINGS: Repair of plasma membrane disruptions and exocytosis of mucus was assessed after treatment of cultured cell models and excised segments of the GI tract with lectins. Plasma membrane disruptions were produced by focal irradiation of individual cells, using a microscope-based laser, or by mechanical abrasion of multiple cells, using a syringe needle. Repair was then assessed by monitoring the cytosolic penetration of dyes incapable of crossing the intact plasma membrane. We found that cell surface-bound lectins potently inhibited plasma membrane repair, and the exocytosis of mucus that normally accompanies the repair response. CONCLUSIONS: Lectins potently inhibit plasma membrane repair, and hence are toxic to wounded cells. This represents a novel form of protein-based toxicity, one that, we propose, is the basis of plant lectin food poisoning

    Rapid flow-sorting to simultaneously resolve multiplex massively parallel sequencing products

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    Sample preparation for Roche/454, ABI/SOLiD and Life Technologies/Ion Torrent sequencing are based on amplification of library fragments on the surface of beads prior to sequencing. Commonly, libraries are barcoded and pooled, to maximise the sequence output of each sequence run. Here, we describe a novel approach for normalization of multiplex next generation sequencing libraries after emulsion PCR. Briefly, amplified libraries carrying unique barcodes are prepared by fluorescent tagging of complementary sequences and then resolved by high-speed flow cytometric sorting of labeled emulsion PCR beads. The protocol is simple and provides an even sequence distribution of multiplex libraries when sequencing the flow-sorted beads. Moreover, since many empty and mixed emulsion PCR beads are removed, the approach gives rise to a substantial increase in sequence quality and mean read length, as compared to that obtained by standard enrichment protocols
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