45 research outputs found

    Characterization of bovine embryos cultured under conditions appropriate for sustaining human naïve pluripotency.

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    In mammalian preimplantation development, pluripotent cells are set aside from cells that contribute to extra-embryonic tissues. Although the pluripotent cell population of mouse and human embryos can be cultured as embryonic stem cells, little is known about the pathways involved in formation of a bovine pluripotent cell population, nor how to maintain these cells in vitro. The objective of this study was to determine the transcriptomic profile related to bovine pluripotency. Therefore, in vitro derived embryos were cultured in various culture media that recently have been reported capable of maintaining the naïve pluripotent state of human embryonic cells. Gene expression profiles of embryos cultured in these media were compared using microarray analysis and quantitative RT-PCR. Compared to standard culture conditions, embryo culture in 'naïve' media reduced mRNA expression levels of the key pluripotency markers NANOG and POU5F1. A relatively high percentage of genes with differential expression levels were located on the X-chromosome. In addition, reduced XIST expression was detected in embryos cultured in naïve media and female embryos contained fewer cells with H3K27me3 foci, indicating a delay in X-chromosome inactivation. Whole embryos cultured in one of the media, 5iLA, could be maintained until 23 days post fertilization. Together these data indicate that 'naïve' conditions do not lead to altered expression of known genes involved in pluripotency. Interestingly, X-chromosome inactivation and development of bovine embryos were dependent on the culture conditions

    Identification of Sare0718 As an Alanine-Activating Adenylation Domain in Marine Actinomycete Salinispora arenicola CNS-205

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    BACKGROUND: Amino acid adenylation domains (A domains) are critical enzymes that dictate the identity of the amino acid building blocks to be incorporated during nonribosomal peptide (NRP) biosynthesis. NRPs represent a large group of valuable natural products that are widely applied in medicine, agriculture, and biochemical research. Salinispora arenicola CNS-205 is a representative strain of the first discovered obligate marine actinomycete genus, whose genome harbors a large number of cryptic secondary metabolite gene clusters. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate cryptic NRP-related metabolites in S. arenicola CNS-205, we cloned and identified the putative gene sare0718 annotated "amino acid adenylation domain". Firstly, the general features and possible functions of sare0718 were predicted by bioinformatics analysis, which suggested that Sare0718 is a soluble protein with an AMP-binding domain contained in the sequence and its cognate substrate is L-Val. Then, a GST-tagged fusion protein was expressed and purified to further explore the exact adenylation activity of Sare0718 in vitro. By a newly mentioned nonradioactive malachite green colorimetric assay, we found that L-Ala but not L-Val is the actual activated amino acid substrate and the basic kinetic parameters of Sare0718 for it are K(m) = 0.1164±0.0159 (mM), V(max) = 3.1484±0.1278 (µM/min), k(cat) = 12.5936±0.5112 (min(-1)). CONCLUSIONS/SIGNIFICANCE: By revealing the biochemical role of sare0718 gene, we identified an alanine-activating adenylation domain in marine actinomycete Salinispora arenicola CNS-205, which would provide useful information for next isolation and function elucidation of the whole cryptic nonribosomal peptide synthetase (NRPS)-related gene cluster covering Sare0718. And meanwhile, this work also enriched the biochemical data of A domain substrate specificity in newly discovered marine actinomycete NRPS system, which bioinformatics prediction will largely depend on

    Nitrate leaching through oxisols of the Loyalty Islands (New Caledonia) under intensified agricultural practices. Geoderma

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    Scope of the journal The primary intention of the journal is to stimulate wide interdisciplinary cooperation and understanding among workers in the different fields of pedology. Therefore, the journal tries to bring together papers from the entire field of soil research, rather than to emphasize any one subdiscipline. Interdisciplinary work should preferably be focused on occurrence and dynamic characterization in space and time of soils in the field. . For 1998 volumes 81-86 are scheduled for publication. Subscription prices are available upon request from the publisher. Subscriptions are accepted on a prepaid basis only and are entered on a calendar year basis. Issues are sent by surface mail except to the following countries where air delivery via SAL is ensured: Argentina, Australia, Brazil, Canada, Hong Kong, India, Israel, Japan, Malaysia, Mexico, New Zealand, Pakistan, PR China, Singapore, South Africa, South Korea, Taiwan, Thailand, USA. For all other countries airmail rates are available upon request. Claims for missing issues must be made within six months of our publication (mailing) date. For orders, claims, product enquiries (no manuscript enquiries) please contact Customer Support Department at the Regional Sales Office nearest to you: Publication information G E O D E W ELSEVIER Abstract For the uplifted coral atolls of the Loyalty Islands (New Caledonia), the prime source of potable water is the freshwater lenses that underlie the islands. The recent adoption of more-intensive agricultural practices, particularly the use of nitrogeneous fertilizers, may, however, represent a threat for these fragile Pacific ecosystems. To assess the risk posed by nitrate leaching, experiments have been conducted on the permeable oxisols of the island of Maré, using both cropped and bare soil sites. Drainage below the root zone was found to be very important, about 50% of the rainfall, even on the cropped site. The soils are thin and permeable, and the frequent tropical storms have high rainfall intensities. Nitrate fertilizers thus have potential to be leached, in large amounts, even up to 100% of the nitrate supply, especially if fertilizers are not supplied according to weather conditions and in concert with the plant's ability to extract them. O 1998 Elsevier Science B.V. All rights reserved

    Non-operative vs. operative treatment for multiple rib fractures after blunt thoracic trauma: a multicenter prospective cohort study

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    Background Patients with multiple rib fractures without a clinical flail chest are increasingly being treated with rib fixation; however, high-quality evidence to support this development is lacking. Methods We conducted a prospective multicenter observational study comparing rib fixation to non-operative treatment in all patients aged 18 years and older with computed tomography confirmed multiple rib fractures without a clinical flail chest. Three centers performed rib fixation as standard of care. For adequate comparison, the other three centers performed only non-operative treatment. As such clinical equipoise formed the basis for the comparison in this study. Patients were matched using propensity score matching. Results In total 927 patients with multiple rib fractures were included. In the three hospitals that performed rib fixation, 80 (14%) out of 591 patients underwent rib fixation. From the nonoperative centers, on average 71 patients were adequately matched to 71 rib fixation patients after propensity score matching. Rib fixation was associated with an increase in hospital length of stay (HLOS) of 4.9 days (95%CI 0.8-9.1, p = 0.02) and a decrease in quality of life (QoL) measured by the EQ5D questionnaire at 1 year of 0.1 (95% CI - 0.2-0.0, p = 0.035) compared to non-operative treatment. A subgroup analysis of patients who received operative care within 72 h showed a similar decrease in QoL. Up to 22 patients (28%) who underwent surgery experienced implant-related irritation. Conclusions We found no benefits and only detrimental effects associated with rib fixation. Based on these results, we do not recommend rib fixation as the standard of care for patients with multiple rib fractures

    Soil properties under Amazon forest and changes due to pasture installation in Rondônia, Brazil Soil properties under Amazon forest and changes due to pasture installation in Rondônia, Brazil

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    Scope of the journal The primary intention of the journal is to stimulate wide interdisciplinary cooperation and understanding among workers in the different fields of pedology. Therefore, the journal tries to bring together papers from the entiire field of soil research, rather than to emphasize any one subdiscipline. Interdisciplinary work should preferably be focused on occurrence and dynamic charactlerizatiorn in space and time of soils in the field. Publication information Geoderma . For 1996 volumes 69-74 are sclheduled for publication. Subscription prices are available upon request from the publisher. Subscriptions are accepted on a prepaid basis only ar;d are entered on a calendar year basis. Issues are sent by surface mail except to the following countries where air delivery via SAL is ensured: Argentina, Australia, Brazil, Canada, Hong Kong, India, Israel, Japan, Malaysia, Mexico, New Zealand, Pakistan, PR China, Singapore, South Africa, South Korea, Taiwan, Thailand, USA. For all other countries airmail rates are available upon request. Claims for missing issues must be made within six months of our publication Abstract We examined the consequences of deforestation and pasture establishment for soil chemical and physical properties and for soil organic matter content, in Rondônia, in the southwestem part of the Brazilian Amazon basin. Two chronosequences were selected. One chronosequence consisted of a forest and pasture established in 1989, 1987, 1983, 1979 and 1972. The main soil type in this area is the red yellow podzolic latosol (Kandiudult). The second chronosequence consisted of a forest site and pasture established in 1987, 1983, 1972 and 1911, and the main soil type is a red yellow podzolic soil (Paleudult, Tropudult). The first soil type is the most base-depleted soil and has a higher clay content than the second one. Despite the initial differences in clay and cations contents between the forest sites the total soil carbon content at 0-30 cm in both forest were circa 3.7 kg C m-*. After pasture installation soil bulk density were higher in the first 0-5 cm soil layer, mainly in one chronosequence but small changes were detected in deeper soil layers. Forest'conversion to pasture caused appreciable increases in soil pH and exchangeable cation content, at least until nine years after pasture installation. pH levels were greater in the first chronosequence, with highest values (6.8 to 7.6) found in 3 and 5 years old pastures respectively. In the most base-depleted soil Ca content increased from 0.07 kg m-2 in the forest site to 0.25 kg m-2 in the 5 year old pasture. After normalization by clay content total soil carbon contents to 30 cm in the 20 year old pastures were 17 to 20% higher than in the original forest sites. Calculations of carbon derived from forest (Cdf) and from pasture (Cdp) using soil 6I3C values showed that Cdf decrease sharply in the first 9 years after pasture establishment in both chronosequences and reached stable values of 2.12 kg C m -2 and 2.02 kg C mb2 in chronosequences 1 and 2,, respectively. Soil carbon derived from pasture increased with time and represented 50% of total (1996) 63-81 soil carbon in the top 30 cm after 20 years of pasture. In general we observed that forest conversion to pasture is associated to a pattern of increasing of soil cations and pH levels for at least 5 years under pasture establishment. The removal of the original forest for pasture establishment resulted in an accumulation of carbon derived from pasture in the soil
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