A multiparental cross population for mapping QTL for agronomic traits in durum wheat (Triticum turgidum ssp. durum).

Multiparental cross designs for mapping quantitative trait loci (QTL) provide an efficient alternative to biparental populations because of their broader genetic basis and potentially higher mapping resolution. We describe the development and deployment of a recombinant inbred line (RIL) population in durum wheat (Triticum turgidum ssp. durum) obtained by crossing four elite cultivars. A linkage map spanning 2664 cM and including 7594 single nucleotide polymorphisms (SNPs) was produced by genotyping 338 RILs. QTL analysis was carried out by both interval mapping on founder haplotype probabilities and SNP bi-allelic tests for heading date and maturity date, plant height and grain yield from four field experiments. Sixteen QTL were identified across environments and detection methods, including two yield QTL on chromosomes 2BL and 7AS, with the former mapped independently from the photoperiod response gene Ppd-B1, while the latter overlapped with the vernalization locus VRN-A3. Additionally, 21 QTL with environment-specific effects were found. Our results indicated a prevalence of environment-specific QTL with relatively small effect on the control of grain yield. For all traits, functionally different QTL alleles in terms of direction and size of genetic effect were distributed among parents. We showed that QTL results based on founder haplotypes closely matched functional alleles at known heading date loci. Despite the four founders, only 2.1 different functional haplotypes were estimated per QTL, on average. This durum wheat population provides a mapping resource for detailed genetic dissection of agronomic traits in an elite background typical of breeding programmes.

The impact of the SSIIa null mutations on grain traits and composition in durum wheat.

Starch represents a major nutrient in the human diet providing essentially a source of energy. More recently the modification of its composition has been associated with new functionalities both at the nutritional and technological level. Targeting the major starch biosynthetic enzymes has been shown to be a valuable strategy to manipulate the amylose-amylopectin ratio in reserve starch. In the present work a breeding strategy aiming to produce a set of SSIIa (starch synthases IIa) null durum wheat is described. We have characterized major traits such as seed weight, total starch, amylose, protein and ß-glucan content in a set of mutant families derived from the introgression of the SSIIa null trait into Svevo, an elite Italian durum wheat cultivar. A large degree of variability was detected and used to select wheat lines with either improved quality traits or agronomic performances. Semolina of a set of two SSIIa null lines showed new rheological behavior and an increased content of all major dietary fiber components, namely arabinoxylans, ß-glucans and resistant starch. Furthermore the investigation of gene expression highlighted important differences in some genes involved in starch and ß-glucans biosynthesis.

Development of COS-SNP and HRM markers for high-throughput and reliable haplotype-based detection of Lr14a in durum wheat (Triticum durum Desf.).

Leaf rust (Puccinia triticina Eriks. & Henn.) is a major disease affecting durum wheat production. The Lr14a-resistant gene present in the durum wheat cv. Creso and its derivative cv. Colosseo is one of the best characterized leaf-rust resistance sources deployed in durum wheat breeding. Lr14a has been mapped close to the simple sequence repeat markers gwm146, gwm344 and wmc10 in the distal portion of the chromosome arm 7BL, a gene-dense region. The objectives of this study were: (1) to enrich the Lr14a region with single nucleotide polymorphisms (SNPs) and high-resolution melting (HRM)-based markers developed from conserved ortholog set (COS) genes and from sequenced Diversity Array Technology (DArT(®)) markers; (2) to further investigate the gene content and colinearity of this region with the Brachypodium and rice genomes. Ten new COS-SNP and five HRM markers were mapped within an 8.0 cM interval spanning Lr14a. Two HRM markers pinpointed the locus in an interval of <1.0 cM and eight COS-SNPs were mapped 2.1-4.1 cM distal to Lr14a. Each marker was tested for its capacity to predict the state of Lr14a alleles (in particular, Lr14-Creso associated to resistance) in a panel of durum wheat elite germplasm including 164 accessions. Two of the most informative markers were converted into KASPar(®) markers. Single assay markers ubw14 and wPt-4038-HRM designed for agarose gel electrophoresis/KASPar(®) assays and high-resolution melting analysis, respectively, as well as the double-marker combinations ubw14/ubw18, ubw14/ubw35 and wPt-4038-HRM-ubw35 will be useful for germplasm haplotyping and for molecular-assisted breeding.

Virulence Phenotypes and Molecular Genotypes in Collections of Puccinia triticina from Italy.

Twenty-four isolates of Puccinia triticina from Italy were characterized for virulence to seedlings of 22 common wheat Thatcher isolines, each with a different leaf rust resistance gene, and for molecular genotypes at 15 simple sequence repeat (SSR) loci. The isolates were compared to a set of 13 previously characterized P. triticina isolates from either durum or common wheat. Clustering based on virulence phenotypes and SSR genotypes grouped the Italian P. triticina isolates into three groups. In the first group, the isolates had virulence phenotypes and SSR genotypes that were similar to the isolates collected from durum wheat. Isolates in the second group were unique because they had virulence similar to the isolates from common wheat but were distinct for SSR genotypes compared to the isolates from durum wheat and from common wheat. Isolates in the third group had virulence phenotypes and SSR genotypes closely related to the isolates from common wheat. The isolates were grouped based on the known or assumed host of origin, virulence phenotype, and SSR genotypes. Measures of FST and RST for SSR genotypes, and ΦST for virulence phenotype were significant, which indicated differentiation among the three groups of isolates. Virulence phenotypes and molecular genotypes were highly correlated with r = 0.74.

Relationship between early administration of abciximab and TIMI flow in STEMI patients undergoing primary angioplasty: findings from a large regional STEMI network.

AIMS: The aim of this study is to assess whether in S-T Elevation Myocardial Infarction (STEMI) a relationship between early administration of abciximab and Thrombolysis In Myocardial Infarction (TIMI) flow before and after primary percutaneous coronary intervention (PCI) in 960 consecutive patients exists. METHODS: From 1 February 2001 onward, in the Province of Mantua it has been operating a 'Cardiology Network for the Acute Infarction Care' having its Hub in the Central Coronary ICU/Cath Lab of Mantua Hospital and being its Spokes centers represented by the emergency rooms and Central Coronary ICUs of the four territorial hospitals. RESULTS: T1 (time from symptoms onset to first medical contact) and T2 (time from first medical contact to angioplasty) are shorter for patients rescued by first aid units rather than for those presented in emergency rooms as well as Ta (time from symptoms onset to abciximab administration). Furthermore, the patients that received abciximab before hospital arrival had less frequently a coronary occlusion [odds ratio = 0.74, 95% confidence interval (0.57-0.96), P = 0.013]. The patients with T1 less than 4 h are 753/960 (78.4%). For this type of patients, there was a significant Ta difference between the pre-PCI TIMI-flow classes (F = 4.467, df = 3, P = 0.04). Planned contrasts revealed that mean time of TIMI flow 0 (M = 104.2) is statistically different from mean time of TIMI flow 3 (M = 85.7), P = 0.013. CONCLUSION: Our results suggest that the use of abciximab, free from pharmacokinetic limits of oral P2Y12 inhibitors, should be considered in STEMI patients with early presentation before primary PCI.

[Pathogenesis of acute coronary syndromes: the activated plaque]. / Patogenesi delle sindromi coronariche acute: la placca attivata.

Atherosclerosis is a chronic disease potentially involving the whole arterial system that causes a spectrum of clinical manifestations ranging from acute myocardial infarction to stable angina or stroke. The continuous accumulation of lipids, and fibrous and inflammatory elements in the arterial wall of the coronary tree leads to progressive lumen narrowing with subsequent ischemia and symptom-limited exercise. Acute coronary syndromes (unstable angina, acute myocardial infarction) have a more complex and dynamic pathogenesis of which coronary plaque rupture and thrombosis represent only the final common pathway that suddenly compromises resting coronary flow. As only some plaques lead to clinical manifestations whereas many others remain asymptomatic, the aim of this review was to analyze the complex mechanisms leading to plaque complication and rupture with respect to systemic and local features.

TILLING mutants of durum wheat result in a high amylose phenotype and provide information on alternative splicing mechanisms.

The amylose/amylopectin ratio has a major influence over the properties of starch and determines its optimal end use. Here, high amylose durum wheat has been bred by combining knock down alleles at the two homoelogous genes encoding starch branching enzyme IIa (SBEIIa-A and SBEIIa-B). The complete silencing of these genes had a number of pleiotropic effects on starch synthesis: it affected the transcriptional activity of SBEIIb, ISA1 (starch debranching enzyme) and all of the genes encoding starch synthases (SSI, SSIIa, SSIII and GBSSI). The starch produced by grain of the double SBEIIa mutants was high in amylose (up to ∼1.95 fold that of the wild type) and contained up to about eight fold more resistant starch. A single nucleotide polymorphism adjacent to the splice site at the end of exon 10 of the G364E mutant copies of both SBEIIa-A and SBEIIa-B resulted in the loss of a conserved exonic splicing silencer element. Its starch was similar to that of the SBEIIa double mutant. G364E SBEIIa pre-mRNA was incorrectly processed, resulting in the formation of alternative, but non-functional splicing products.

Postendocarditis mitral valve aneurysm.

Mitral valve aneurysm is defined as a localized, thin-walled, saccular bulge of the mitral leaflet toward the left atrium. In this study, we report a case of mitral aneurysm of the posterior leaflet (scallop P3) secondary to primary mitral endocarditis in a patient who underwent prosthetic aortic valve replacement and coronary artery bypass graft.

[A database in the coronary care unit to assess quality of care of acute myocardial infarction]. / Utilità di un database in unità di terapia intensiva coronarica come strumento di verifica della qualità della cura dell'infarto miocardico acuto.

BACKGROUND: In the context of an operative network for acute coronary syndrome consisting in telemedicine equipment and 24-h catheter facility availability, a database was worked out to verify clinical pathways, timeline, prevalence of cardiovascular risk factors, diagnostic and therapeutic choices, and clinical results. The aim of this study was to evaluate the adherence to guidelines in the real world in order to assess quality of care. METHODS: We implemented a database in the preexisting hospital intranet due to open source interactive pages. From international guidelines we obtained performance measures for each step of the care process, in order to have a continuous and updated evaluation of our healthcare performance. After an accurate analysis of the results of the first 2-year data collection, we modified the performance measurement set to optimize our database. All data were analyzed with statistical program SPSS. RESULTS: A total of 1066 patient characteristics within a period of 5 semesters were analyzed: trends for each of the 11 performance measures were evaluated. In 852 patients clinical and angiographic characteristics were analyzed: cardiovascular risk factors and TIMI risk score for ST-elevation myocardial infarction patients, different pathways and first-aid timeline. Data about pharmacological therapy on admission, during intensive care unit stay and at discharge were also collected. CONCLUSIONS: The present study assesses the utility of continuous monitoring and of verifying quality of care with a dedicated database in order to evaluate adherence to guidelines and to promote optimization of clinical practice.

Long-term outcomes in patients undergoing coronary stenting on dual oral antiplatelet treatment requiring oral anticoagulant therapy.

In patients undergoing coronary stenting, long-term dual antiplatelet therapy with aspirin and clopidogrel reduces atherothrombotic events but also increases the risk of bleeding. The potential for developing bleeding complications is further enhanced in patients also requiring oral anticoagulant treatment ("triple therapy"). The aim of the study is to assess long-term outcomes associated with the use of triple-therapy in patients undergoing coronary stenting and evaluate how these may be affected by targeting international normalized ratio (INR) values to the lower therapeutic range. We prospectively studied 102 consecutive patients undergoing coronary stenting treated with dual antiplatelet therapy also requiring oral anticoagulation. INR was targeted to the lower therapeutic range (2.0 to 2.5). Patients requiring oral anticoagulant therapy because of mechanical valve prosthesis were excluded. Patients were followed for 18 months, and bleeding, defined according to Thrombolysis in Myocardial Infarction criteria, and major adverse cardiac events were recorded. Outcomes were compared with a control group (n = 102) treated only with dual antiplatelet therapy. The mean duration of triple therapy was 157 +/- 134 days. At 18 months, a nonsignificant increase in bleeding was observed in the triple versus dual therapy group (10.8% vs 4.9%, p = 0.1). INR values were higher in patients with bleeding (2.8 +/- 1.1 vs 2.3 +/- 0.2, p = 0.0001). In patients who had INR values within the recommended target (79.4%), the risk of bleeding was significantly lower compared with patients who did not (4.9 vs 33%, p = 0.00019) and with that observed in the control group (4.9%). An INR >2.6 was the only independent predictor of bleeding. There were no significant differences in major adverse cardiac events between groups (5.8% vs 4.9%, p = 0.7). In conclusion, in patients undergoing coronary stenting on triple therapy, targeting lower therapeutic INR values reduces the risk of bleeding complications.

Nucleotide-binding site (NBS) profiling of genetic diversity in durum wheat.

Molecular markers are effective tools to investigate genetic diversity for resistance to pathogens. NBS (nucleotide-binding site) profiling is a PCR (polymerase chain reaction)-based approach to studying genetic variability that specifically targets chromosome regions containing R-genes and R-gene analogues. We used NBS profiling to measure genetic diversity among 58 accessions of durum wheat. Mean polymorphism rates detected using MseI and AluI as restriction enzymes were 34% and 22%, respectively. Mean number of polymorphisms per enzyme-primer combination was equal to 23.8 +/- 5.9, ranging from 13 to 31 polymorphic bands. In total, 96 markers over 190 indicated a good capacity to discriminate between accessions (the polymorphic index content ranging from 0.30 to 0.50). The results obtained with NBS profiling were compared with simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) data of the same set of accessions. The genetic distances computed with 190 NBS profiling markers were in close agreement with those obtained with AFLP and SSR markers (r = 0.73 and 0.76, respectively). Our results indicate that NBS profiling provides an effective means to investigate genetic diversity in durum wheat.