65 research outputs found

    Arch and access vessel complications in penetrating aortic ulcer managed with thoracic endovascular aortic repair

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    Background: To analyze our experience and to describe access and arch-related challenges when performing thoracic endovascular aortic repair (TEVAR) for penetrating aortic ulcers (PAUs).Methods: This is a single-center, observational, cohort study. Between October 2003 and February 2019, 48 patients with PAU were identified; 37 (77.1%) treated with TEVAR were retrospectively analyzed. Primary major outcomes were early (< 30 days) and late survival, freedom from aortic-related mortality (ARM), and a composite endpoint of arch/vascular access-related complications.Results: On admission, 17 (45.9%) patients were symptomatic with 4 (10.8%) presenting with rupture. Inhospital mortality was 8.1% (n=3). We observed 10 (27.0%) arch/access-related complications. There were 4 (10.8%) arch issues: 2 transient ischemic attacks and 2 retrograde acute type A dissections which required emergent open conversion for definitive repair. Access issues occurred in 6 (16.2%) patients: 3 (8.1%) required common iliac artery conduit, and 1 (2.7%) patient required iliac artery angioplasty to deliver the stent-graft. In addition, 2 (5.4%) patients developed access complications which required operative repair [femoral patch angioplasty (n=2), and femoral pseudoaneurysmectomy (n=1)]. Arch/access-related mortality rate was 5.4% (n=2) and median follow-up was 24 (range, 1-156; IQR, 3-52) months. Estimated survival was 87.1% (standard error: 0.6; 95% CI: 71.2-84.9%) at 1 year, and 63.3% (SE: 0.9; 95% CI: 44.1-79%) at 4 years. Estimated freedom from reintervention was 88.9% (SE: 0.5; 95% CI: 74.8-95.6%) at 1 year, and 84.2% (SE: 0.7; 95% CI: 67.3-93.2%) at 4 years. No arch/access-related issues developed during the follow-up period.Conclusions: Our experience confirms that vascular access and aortic arch issues are still a challenging aspect of performing TEVAR for PAUs. Our cumulative 27% rate of access/arch issues is lower than previously reported due to both technological advancements and meticulous management of both access routes and arch anatomy

    On the role of ethylene, auxin and a GOLVEN-like peptide hormone in the regulation of peach ripening

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    Background: In melting flesh peaches, auxin is necessary for system-2 ethylene synthesis and a cross-talk between ethylene and auxin occurs during the ripening process. To elucidate this interaction at the transition from maturation to ripening and the accompanying switch from system-1 to system-2 ethylene biosynthesis, fruits of melting flesh and stony hard genotypes, the latter unable to produce system-2 ethylene because of insufficient amount of auxin at ripening, were treated with auxin, ethylene and with 1-methylcyclopropene (1-MCP), known to block ethylene receptors. The effects of the treatments on the different genotypes were monitored by hormone quantifications and transcription profiling. Results: In melting flesh fruit, 1-MCP responses differed according to the ripening stage. Unexpectedly, 1-MCP induced genes also up-regulated by ripening, ethylene and auxin, as CTG134, similar to GOLVEN (GLV) peptides, and repressed genes also down-regulated by ripening, ethylene and auxin, as CTG85, a calcineurin B-like protein. The nature and transcriptional response of CTG134 led to discover a rise in free auxin in 1-MCP treated fruit. This increase was supported by the induced transcription of CTG475, an IAA-amino acid hydrolase. A melting flesh and a stony hard genotype, differing for their ability to synthetize auxin and ethylene amounts at ripening, were used to study the fine temporal regulation and auxin responsiveness of genes involved in the process. Transcriptional waves showed a tight interdependence between auxin and ethylene actions with the former possibly enhanced by the GLV CTG134. The expression of genes involved in the regulation of ripening, among which are several transcription factors, was similar in the two genotypes or could be rescued by auxin application in the stony hard. Only GLV CTG134 expression could not be rescued by exogenous auxin. Conclusions: 1-MCP treatment of peach fruit is ineffective in delaying ripening because it stimulates an increase in free auxin. As a consequence, a burst in ethylene production speeding up ripening occurs. Based on a network of gene transcriptional regulations, a model in which appropriate level of CTG134 peptide hormone might be necessary to allow the correct balance between auxin and ethylene for peach ripening to occur is proposed

    The regulation of MADS-box gene expression during ripening of banana and their regulatory interaction with ethylene

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    Six MaMADS-box genes have been cloned from the banana fruit cultivar Grand Nain. The similarity of these genes to tomato LeRIN is low and neither MaMADS2 nor MaMADS1 complement the tomato rin mutation. Nevertheless, the expression patterns, specifically in fruit and the induction during ripening and in response to ethylene and 1-MCP, suggest that some of these genes may participate in ripening. MaMADS1, 2, and 3, are highly expressed in fruit only, while the others are expressed in fruit as well as in other organs. Moreover, the suites of MaMADS-box genes and their temporal expression differ in peel and pulp during ripening. In the pulp, the increase in MaMADS2, 3, 4, and 5 expression preceded an increase in ethylene production, but coincides with the CO2 peak. However, MaMADS1 expression in pulp coincided with ethylene production, but a massive increase in its expression occurred late during ripening, together with a second wave in the expression of MaMADS2, 3, and 4. In the peel, on the other hand, an increase in expression of MaMADS1, 3, and to a lesser degree also of MaMADS4 and 2 coincided with an increase in ethylene production. Except MaMADS3, which was induced by ethylene in pulp and peel, only MaMADS4, and 5 in pulp and MaMADS1 in peel were induced by ethylene. 1-MCP applied at the onset of the increase in ethylene production, increased the levels of MaMADS4 and MaMADS1 in pulp, while it decreased MaMADS1, 3, 4, and 5 in peel, suggesting that MaMADS4 and MaMADS1 are negatively controlled by ethylene at the onset of ethylene production only in pulp. Only MaMADS2 is neither induced by ethylene nor by 1-MCP, and it is expressed mainly in pulp. Our results suggest that two independent ripening programs are employed in pulp and peel which involve the activation of mainly MaMADS2, 4, and 5 and later on also MaMADS1 in pulp, and mainly MaMADS1, and 3 in peel. Hence, our results are consistent with MaMADS2, a SEP3 homologue, acting in the pulp upstream of the increase in ethylene production similarly to LeMADS-RIN

    Functional Analysis of the Arlequin Mutant Corroborates the Essential Role of the ARLEQUIN/TAGL1 Gene during Reproductive Development of Tomato

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    Reproductive development of higher plants comprises successive events of organ differentiation and growth which finally lead to the formation of a mature fruit. However, most of the genetic and molecular mechanisms which coordinate such developmental events are yet to be identified and characterized. Arlequin (Alq), a semi-dominant T-DNA tomato mutant showed developmental changes affecting flower and fruit ripening. Sepals were converted into fleshy organs which ripened as normal fruit organs and fruits displayed altered ripening features. Molecular characterization of the tagged gene demonstrated that it corresponded to the previously reported TOMATO AGAMOUS-LIKE 1 (TAGL1) gene, the tomato ortholog of SHATTERPROOF MADS-box genes of Arabidopsis thaliana, and that the Alq mutation promoted a gain-of-function phenotype caused by the ectopic expression of TAGL1. Ectopic overexpression of TAGL1 resulted in homeotic alterations affecting floral organ identity that were similar to but stronger than those observed in Alq mutant plants. Interestingly, TAGL1 RNAi plants yielded tomato fruits which were unable to ripen. They displayed a yellow-orange color and stiffness appearance which are in accordance with reduced lycopene and ethylene levels, respectively. Moreover, pericarp cells of TAGL1 RNAi fruits showed altered cellular and structural properties which correlated to both decreased expression of genes regulating cell division and lignin biosynthesis. Over-expression of TAGL1 is able to rescue the non-ripening phenotype of rin and nor mutants, which is mediated by the transcriptional activation of several ripening genes. Our results demonstrated that TAGL1 participates in the genetic control of flower and fruit development of tomato plants. Furthermore, gene silencing and over-expression experiments demonstrated that the fruit ripening process requires the regulatory activity of TAGL1. Therefore, TAGL1 could act as a linking factor connecting successive stages of reproductive development, from flower development to fruit maturation, allowing this complex process to be carried out successfully

    Variations of the peach fruit transcriptome during ripening and in response to hormone treatments

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    Peach has fleshy climacteric fruits. Their ripening is controlled by both endogenous and exogenous signals to link the genetic determinants with the environmental conditions. Genomic tools, such as microarray RNA profiling, offer new prospects to study in a holistic way complex biological problems such as fruit ripening. We have adopted a microarray approach to monitor transcriptome changes in peach fruits during their transition from a pre-climacteric to a climacteric stage. Furthermore, the variations of gene transcription mediated by applications of exogenous ethylene and auxin to pre-climacteric fruits have also been analysed. In peach fruits the ripening process needs vast transcriptional changes to occur, and the hormone ethylene controls many of these changes. Among the many variations occurring during ripening, we observed that some genes coding for various isoforms of the glycolytic enzymes were up-regulated. Several hypotheses are presented to account for these results
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