27 research outputs found

    Elevated Atmospheric CO2 Affects Ectomycorrhizal Species Abundance and Increases Sporocarp Production under Field Conditions

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    Anthropogenic activities during the last century have increased levels of atmospheric CO2. Forest net primary productivity increases in response to elevated CO2, altering the quantity and quality of carbon supplied to the rhizosphere. Ectomycorrhizal fungi form obligate symbiotic associations with the fine roots of trees that mediate improved scavenging for nutrients in exchange for a carbohydrate supply. Understanding how the community structure of ectomycorrhizal fungi is altered by climate change is important to further our understanding of ecosystem function. Betula pendula and Fagus sylvatica were grown in an elevated CO2 atmosphere delivered using free air carbon dioxide enrichment (FACE) under field conditions in the U.K., and Picea abies was grown under elevated CO2 in glass domes in the Czech Republic. We used morphotyping and sequencing of the internal transcribed spacer region of the fungal ribosomal operon to study ectomycorrhizal community structure. Under FACE, un-colonised roots tips increased in abundance for Fagus sylvatica, and during 2006, sporocarp biomass of Peziza badia significantly increased. In domes, ectomycorrhizal community composition shifted from short-distance and smooth medium-distance to contact exploration types. Supply and competition for carbon belowground can influence ectomycorrhizal community structure with the potential to alter ecosystem function

    Prevalence, severity and correlates of fatigue in newly diagnosed patients with myelodysplastic syndromes

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    The primary objective of this study was to investigate factors associated with fatigue severity in newly diagnosed patients with higher-risk myelodysplastic syndromes (MDS). The secondary objectives were to assess symptom prevalence and to examine the relationships between fatigue, quality of life (QoL) and overall symptom burden in these patients. The analyses were conducted in 280 higher-risk MDS patients. Pre-treatment patient-reported fatigue was evaluated with the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue scale and QoL was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30). Female gender (P = 0·018), poor performance status (i.e., ECOG of 2-4) (P < 0·001) and lower levels of haemoglobin (Hb) (P = 0·026) were independently associated with higher fatigue severity. The three most prevalent symptoms were as follows: fatigue (92%), dyspnoea (63%) and pain (55%). Patients with higher levels of fatigue also had greater overall symptom burdens. The mean global QoL scores of patients with the highest versus those with the lowest levels of fatigue were 29·2 [standard deviation (SD), 18·3] and 69·0 (SD, 18·8), respectively and this difference was four times the magnitude of a clinically meaningful difference. Patient-reported fatigue severity revealed the effects of disease burden on overall QoL more accurately than did degree of anaemia. Special attention should be given to the female patients in the management of fatigue

    Treatment of Chronic Myelomonocytic Leukemia with 5-Azacytidine: Case Reports

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    Epigenetic therapy with hypomethylating agent (5-azacytidine; AZA) is common in the management of specific subtypes of myelodysplastic syndrome (MDS), but there are only few studies in chronic myelomonocytic leukemia (CMML) patients. In this paper our experience with 3 CMML patients treated with AZA is described. In one patient transfusion independency was observed after 4 treatment cycles; in one case a partial response was recorded, but a progression to acute myeloid leukemia (AML) after 13 AZA cycles has appeared. In one patient, AZA in reduced dosage was administered as a bridging treatment before allogeneic stem cell transplantation (ASCT), but in the control bone marrow aspirate (before ASCT) a progression to AML was recorded. Future studies are mandatory for evaluation of new molecular and clinical features which could predict the efficiency of hypomethylating agents in CMML therapy with respect to overall survival, event-free survival, quality-adjusted life year, and pharmacoeconomy

    Relationship between Altered miRNA Expression and DNA Methylation of the DLK1-DIO3 Region in Azacitidine-Treated Patients with Myelodysplastic Syndromes and Acute Myeloid Leukemia with Myelodysplasia-Related Changes

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    The DLK1&ndash;DIO3 region contains a large miRNA cluster, the overexpression of which has previously been associated with myelodysplastic syndromes (MDS). To reveal whether this overexpression is epigenetically regulated, we performed an integrative analysis of miRNA/mRNA expression and DNA methylation of the regulatory sequences in the region (promoter of the MEG3 gene) in CD34+ bone marrow cells from the patients with higher-risk MDS and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), before and during hypomethylating therapy with azacytidine (AZA). Before treatment, 50% of patients showed significant miRNA/mRNA overexpression in conjunction with a diagnosis of AML-MRC. Importantly, increased level of MEG3 was associated with poor outcome. After AZA treatment, the expression levels were reduced and were closer to those seen in the healthy controls. In half of the patients, we observed significant hypermethylation in a region preceding the MEG3 gene that negatively correlated with expression. Interestingly, this hypermethylation (when found before treatment) was associated with longer progression-free survival after therapy initiation. However, neither expression nor methylation status were associated with future responsiveness to AZA treatment. In conclusion, we correlated expression and methylation changes in the DLK1&ndash;DIO3 region, and we propose a complex model for regulation of this region in myelodysplasia

    CTCF/SMARCA5 are recruited to <i>SPI1</i> locus in myeloid cells and upon AZA treatment in AML.

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    <p><b>A:</b> Sequence conservation of human <i>SPI1</i> locus (VISTA) generated by aligning with murine DNA. Regulatory regions and positions of ChIP amplicons are numbered in respect to human <i>SPI1</i> TSS. <b>B:</b> ChIP of CTCF and SMARCA5 in mixed myeloid cells. <b>C:</b> ChIP of CTCF and <b>D:</b> SMARCA5 in OCI-M2 without (OCI-M2) or with AZA (OCI-M2 AZA) treatment. Y-axis: ChIP enrichment. X-axis: amplicons (distance relative to <i>SPI1</i> TSS). URE, Upstream Regulatory Element of <i>SPI1</i> gene; ENH, enhancer; ELE, element. Error bars: the standard errors (SE). Asterisks: p-values (t-test, 0.05–0.005).</p
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