Search

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a major wheat disease that can inflict yield losses of up to 70% on susceptible varieties under favourable environmental conditions. The timely identification of plant genetic resources likely to possess novel resistance to this disease would facilitate the rapid development of resistant wheat varieties. The focused identification of germplasm strategy (FIGS) approach was used to predict stripe rust resistance in a collection of wheat landraces conserved at ICARDA genebank. Long-term climate data for the collection sites, from which these accessions originated and stripe rust evaluation scores for one group of accessions were presented to three different non-linear models to explore the trait×collection site environment interactions. Patterns in the data detected by the models were used to predict stripe rust resistance in a second and different set of accessions. The results of the prediction were then tested against actual evaluation scores of the disease in the field. The study mimics the real scenario where requests are made to plant genetic resources curators to provide accessions that are likely to possess variation for specific traits such as disease resistance.The models used were able to identify stripe rust-resistant accessions with a high degree of accuracy. Values as high as 0·75 for area under the curve and 0·45 for Kappa statistics, which quantify the agreement between the models’ predictions and the curator's disease scores, were achieved. This demonstrates a strong environmental component in the geographic distribution of resistance genes and therefore supports the theoretical basis for FIGS. It is argued that FIGS will improve the rate of gene discovery and efficiency of mining genetic resource collections for adaptive traits by reducing the number of accessions that are normally required for evaluation to identify such variation. [ABSTRACT FROM PUBLISHER]

This article discusses research on the prevalence of mutations of epigenetic regulators and of spliceosome enzymes as transforming events in therapy-related myeloid neoplasms (t-MN) compared with leukemias that evolved from chronic myeloproliferative neoplasms (MPN). Researchers learned that the highest frequency of mutations in acute leukemias evolved from MPN. They also revealed that the incidence of mutations varies in t-MN according to the type of previous malignancy.

BRCA1 plays a pivotal role in the repair of DNA damage, especially following chemotherapy and ionising radiation. We were interested in the regulation of BRCA1 expression in acute myeloid leukaemia (AML), in particular in therapy-related forms (t-AML). Using real-time PCR and Western blot, we found that BRCA1 mRNA was expressed at barely detectable levels by normal peripheral blood granulocytes, monocytes and lymphocytes, whereas control BM-mononuclear cells and selected CD34+ progenitor cells displayed significantly higher BRCA1 expression (P=0.0003). Acute myeloid leukaemia samples showed heterogeneous BRCA1 mRNA levels, which were lower than those of normal bone marrows (P=0.0001). We found a high frequency of hypermethylation of the BRCA1 promoter region in AML (51/133 samples, 38%), in particular in patients with karyotypic aberrations (P=0.026), and in t-AML, as compared to de novo AML (76 vs 31%, P=0.0002). Examining eight primary tumour samples from hypermethylated t-AML patients, BRCA1 was hypermethylated in three of four breast cancer samples, whereas it was unmethylated in the other four tumours. BRCA1 hypermethylation correlated to reduced BRCA1 mRNA (P=0.0004), and to increased DNA methyltransferase DNMT3A (P=0.003) expression. Our data show that reduced BRCA1 expression owing to promoter hypermethylation is frequent in t-AML and that this could contribute to secondary leukaemogenesis.British Journal of Cancer (2006) 95, 1108–1113. doi:10.1038/sj.bjc.6603392 www.bjcancer.com [ABSTRACT FROM AUTHOR]

Objectives: The treatment of deep vein thrombosis (DVT) of the lower limbs during pregnancy remains controversial. There are a lot of problems related to anticoagulant therapy for the safety of the fetus; the use of caval filters rarely appears in the literature and it is not yet codified. So the choice of the right treatment is often difficult. The authors review their experience with a prophylactic use of a temporary caval filter for patients with proximal DVT of the last period of pregnancy, in order to avoid the inherent risk of major pulmonary embolism during delivery and postpartum. Methods: Ten women with proximal DVT were treated. The diagnosis was performed by Doppler ultrasonography (DU) and magnetic resonance (MR). At the end of pregnancy, a temporary caval filter (eight Prolyser and two Tempofilter) was percutaneously inserted under X-ray control. The patients were then subjected to a planned caesarean section. After 15 days, all filters were removed after a phlebography to check the absence of clots. Results: The mean time of X-ray exposure was about 1 min and 30 s. None of the patients suffered a major pulmonary embolism. All fetuses were born without problems or malformations. There were no complications related to the filters. No caval thrombosis or filters clots were found at the phlebography. The follow-up registered no pulmonary embolism episodes. Conclusions: The use of a temporary caval filter in pregnancy is safe and does not introduce any additional risk. It could be suggested for pregnant patients with proximal DVT beginning in the last period of pregnancy. [ABSTRACT FROM AUTHOR]