101 research outputs found

    Relaciones franco-alemanas: ¿Un nuevo ‘look’ o un nuevo acuerdo?

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    En los últimos años se ha afirmado en múltiples ocasiones que la estrecha relación entre Francia y Alemania, motor de la integración europea en la segunda mitad del siglo pasado, había pasado a mejor vida. No obstante, ha quedado demostrado que las necrológicas fueron prematuras. De nuevo, en un contexto de ampliación de la Unión Europea a un mínimo de 25 miembros, la relación se enfrentaba a retos sin precedentes. Sin embargo, la llegada de una repentina avalancha de importantes acuerdos logrará quizás insuflar nueva vida a la asociación entre estos dos viejos socios. Con motivo de la celebración del 40 aniversario del Tratado del Elíseo, celebrado en enero de 2003, los dos países parecían dispuestos a buscar formas de reafirmar la validez de su amistad estratégica. Los recientes signos de dinamismo de esta relación deberán, sin embargo, marcar el principio de un nuevo acuerdo fundamental si Francia y Alemania quieren desempeñar su papel tradicional como impulsores de la unificación europea en el futuro

    Construction of carbocycles via oxonium ylides generation and rearrangement: towards the synthesis of taxol

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    The diterpenoid natural product Taxol, first discovered in the late 1960’s, is one of the most important current drugs for the treatment of several cancers including breast and ovarian cancers. Although tremendous efforts towards its synthesis have been made in the last two decades, resulting in six elegant total syntheses, Taxol still constitutes a remarkable challenge for organic chemists due to its unique structural framework. The high level of interest has spilled over to our laboratory, the purpose of this thesis was to develop an approach for the construction of medium-ring fused polycarbocyclic systems, which would then be applied to the synthesis of the sterically hindered eight-membered ring of the tricyclic core system of Taxol. Described herein is the continuation of efforts focused towards the access of fused medium-ring carbocycles by tandem catalytic oxonium ylide generation and rearrangement. The novel method in which intramolecular reaction of metal carbenoids with α-vinyl ethers and subsequent [2,3]-rearrangement of the cyclic oxonium ylide intermediates has been used as a powerful strategy to produce linearly fused bicyclic and tricyclic systems. Following the success of our methodology, a key diazoketone intermediate was chosen to establish the viability of our strategy, before embarking on the total synthesis of Taxol. The efficient synthesis of the required diazoketone is discussed in detail, after the exploration of many different approaches. Finally, studies concerning the catalytic decomposition of the diazoketone towards the tricyclic core system of Taxol are presented

    “Crochetage” (Notch) on R wave in inferior limb leads: A new independent electrocardiographic sign of atrial septal defect

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    AbstractObjectives. This study sought to determine the clinical significance of a “crochetage” pattern—a notch near the apex of the R wave in electrocardiographic (ECG) inferior limb leads—in secundum atrial septal defect.Background. Atrial septal defect is often overdiagnosed on the basis of classical clinical features. Thus, more specific signs on the ECG for screening are needed.Methods. We searched for a crochetage pattern in 1,560 older children and adults: 532 with secundum atrial septal defect, 266 with ventricular septal defect, 146 with pulmonary stenosis, 110 with mitral stenosis, 47 with cor pulmonale and 459 normal subjects.Results. This pattern was observed respectively in 73.1%, 35.7%, 23.3%, 6.4%, 10.6% and 7.4% of these groups (p < 0.001). In atrial septal defect, its incidence increased with larger anatomic defect (p < 0.0001) or greater left-to-right shunt (p < 0.0001), even in the presence of pulmonary hypertension. By multiple regression analysis, only shunt size (p < 0.0006) and defect location (p < 0.0001) were the determinants of its presence. In all groups, the specificity of this sign for the diagnosis was remarkably high when present in all three inferior limb leads (≥92%), even when comparison was limited to patients with an incomplete right bundle branch block (≥95.2%). Early disappearance of this pattern was observed in 35.1% of the operated-on patients although the right bundle branch block pattern persisted.Conclusions. A crochetage pattern of the R wave in inferior limb leads is frequent in patients with atrial septal defect, correlates with shunt severity and is independent of the right bundle branch block pattern. Sensitivity and specificity of this sign are remarkably high when it is associated with an incomplete right bundle branch block or present in all inferior limb leads

    Different oral corticosteroid regimens for acute asthma.

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    BACKGROUND: Asthma is a common long-term breathing condition that affects approximately 300 million people worldwide. People with asthma may experience short-term worsening of their asthma symptoms; these episodes are often known as 'exacerbations', 'flare-ups', 'attacks' or 'acute asthma'. Oral steroids, which have a potent anti-inflammatory effect, are recommended for all but the most mild asthma exacerbations; they should be initiated promptly. The most often prescribed oral steroids are prednisolone and dexamethasone, but current guidelines on dosing vary between countries, and often among different guideline producers within the same country. Despite their proven efficacy, use of steroids needs to be balanced against their potential to cause important adverse events. Evidence is somewhat limited regarding optimal dosing of oral steroids for asthma exacerbations to maximise recovery while minimising potential side effects, which is the topic of this review. OBJECTIVES: To assess the efficacy and safety of any dose or duration of oral steroids versus any other dose or duration of oral steroids for adults and children with an asthma exacerbation. SEARCH METHODS: We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. This search was up to date as of April 2016. SELECTION CRITERIA: We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated one dose or duration of oral steroid versus any other dose or duration, for management of asthma exacerbations. We included studies involving both adults and children with asthma of any severity, in which investigators analysed adults and children separately. We allowed any other co-intervention in the management of an asthma exacerbation, provided it was not part of the randomised treatment. We included studies reported as full text, those published as abstract only and unpublished data. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias; all data were cross-checked for accuracy. We resolved disagreements by discussion with the third review author or with an external advisor.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs). We used a random-effects model, and we carried out a fixed-effect analysis if we detected statistical heterogeneity. We rated all outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) system and presented results in 'Summary of findings' tables. MAIN RESULTS: We included 18 studies that randomised a total of 2438 participants - both adults and children - and performed comparisons of interest. Included studies assessed higher versus lower doses of prednisolone (n = 4); longer versus shorter courses of prednisolone (n = 3) or dexamethasone (n = 1); tapered versus non-tapered courses of prednisolone (n = 4); and prednisolone versus dexamethasone (n = 6). Follow-up duration ranged from seven days to six months. The smallest study randomised just 15 participants, and the largest 638 (median 93). The varied interventions and outcomes reported limited the number of meaningful meta-analyses that we could perform.For two of our primary outcomes - hospital admission and serious adverse events - events were too infrequent to permit conclusions about the superiority of one treatment over the other, or their equivalence. Researchers in the included studies reported asthma symptoms in different ways and rarely used validated scales, again limiting our conclusions. Secondary outcome meta-analysis was similarly hampered by heterogeneity among interventions and outcome measures used. Overall, we found no convincing evidence of differences in outcomes between a higher dose or longer course and a lower dose or shorter course of prednisolone or dexamethasone, or between prednisolone and dexamethasone.Included studies were generally of reasonable methodological quality. Review authors assessed most outcomes in the review as having low or very low quality, meaning we are not confident in the effect estimates. The predominant reason for downgrading was imprecision, but indirectness and risk of bias also reduced our confidence in some estimates. AUTHORS' CONCLUSIONS: Evidence is not strong enough to reveal whether shorter or lower-dose regimens are generally less effective than longer or higher-dose regimens, or indeed that the latter are associated with more adverse events. Any changes recommended for current practice should be supported by data from larger, well-designed trials. Varied study design and outcome measures limited the number of meta-analyses that we could perform. Greater emphasis on palatability and on whether some regimens might be easier to adhere to than others could better inform clinical decisions for individual patients

    Noninvasive ventilation in COVID-19 patients aged ≥ 70 years—a prospective multicentre cohort study

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    Funding Information: COVIP study did not have any funding. Publication of this article was funded by the Priority Research Area qLife under the program “Excellence Initiative – Research University” at the Jagiellonian University in Krakow (06/IDUB/2019/94). Publisher Copyright: © 2022, The Author(s).Background: Noninvasive ventilation (NIV) is a promising alternative to invasive mechanical ventilation (IMV) with a particular importance amidst the shortage of intensive care unit (ICU) beds during the COVID-19 pandemic. We aimed to evaluate the use of NIV in Europe and factors associated with outcomes of patients treated with NIV. Methods: This is a substudy of COVIP study—an international prospective observational study enrolling patients aged ≥ 70 years with confirmed COVID-19 treated in ICU. We enrolled patients in 156 ICUs across 15 European countries between March 2020 and April 2021.The primary endpoint was 30-day mortality. Results: Cohort included 3074 patients, most of whom were male (2197/3074, 71.4%) at the mean age of 75.7 years (SD 4.6). NIV frequency was 25.7% and varied from 1.1 to 62.0% between participating countries. Primary NIV failure, defined as need for endotracheal intubation or death within 30 days since ICU admission, occurred in 470/629 (74.7%) of patients. Factors associated with increased NIV failure risk were higher Sequential Organ Failure Assessment (SOFA) score (OR 3.73, 95% CI 2.36–5.90) and Clinical Frailty Scale (CFS) on admission (OR 1.46, 95% CI 1.06–2.00). Patients initially treated with NIV (n = 630) lived for 1.36 fewer days (95% CI − 2.27 to − 0.46 days) compared to primary IMV group (n = 1876). Conclusions: Frequency of NIV use varies across European countries. Higher severity of illness and more severe frailty were associated with a risk of NIV failure among critically ill older adults with COVID-19. Primary IMV was associated with better outcomes than primary NIV. Clinical Trial RegistrationNCT04321265, registered 19 March 2020, https://clinicaltrials.gov.publishersversionpublishe

    The EpsE Flagellar Clutch Is Bifunctional and Synergizes with EPS Biosynthesis to Promote Bacillus subtilis Biofilm Formation

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    Many bacteria inhibit motility concomitant with the synthesis of an extracellular polysaccharide matrix and the formation of biofilm aggregates. In Bacillus subtilis biofilms, motility is inhibited by EpsE, which acts as a clutch on the flagella rotor to inhibit motility, and which is encoded within the 15 gene eps operon required for EPS production. EpsE shows sequence similarity to the glycosyltransferase family of enzymes, and we demonstrate that the conserved active site motif is required for EPS biosynthesis. We also screen for residues specifically required for either clutch or enzymatic activity and demonstrate that the two functions are genetically separable. Finally, we show that, whereas EPS synthesis activity is dominant for biofilm formation, both functions of EpsE synergize to stabilize cell aggregates and relieve selective pressure to abolish motility by genetic mutation. Thus, the transition from motility to biofilm formation may be governed by a single bifunctional enzyme

    The Staphylococcus aureus Response to Unsaturated Long Chain Free Fatty Acids: Survival Mechanisms and Virulence Implications

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    Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR) and translational (proteomics) analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the σB and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM) and transposon-derived mutants (vraE, SAR2632) was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered pathogenesis as assessed by a murine arthritis model. Differences in the prevalence and clinical importance of S. aureus strains might partly be explained by their responses to antimicrobial fatty acids

    Increased 30-Day Mortality in Very Old ICU Patients with COVID-19 Compared to Patients with Respiratory Failure without COVID-19

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    Purpose: The number of patients ≥ 80 years admitted into critical care is increasing. Coronavirus disease 2019 (COVID-19) added another challenge for clinical decisions for both admission and limitation of life-sustaining treatments (LLST). We aimed to compare the characteristics and mortality of very old critically ill patients with or without COVID-19 with a focus on LLST. Methods: Patients 80 years or older with acute respiratory failure were recruited from the VIP2 and COVIP studies. Baseline patient characteristics, interventions in intensive care unit (ICU) and outcomes (30-day survival) were recorded. COVID patients were matched to non-COVID patients based on the following factors: age (± 2 years), Sequential Organ Failure Assessment (SOFA) score (± 2 points), clinical frailty scale (± 1 point), gender and region on a 1:2 ratio. Specific ICU procedures and LLST were compared between the cohorts by means of cumulative incidence curves taking into account the competing risk of discharge and death. Results: 693 COVID patients were compared to 1393 non-COVID patients. COVID patients were younger, less frail, less severely ill with lower SOFA score, but were treated more often with invasive mechanical ventilation (MV) and had a lower 30-day survival. 404 COVID patients could be matched to 666 non-COVID patients. For COVID patients, withholding and withdrawing of LST were more frequent than for non-COVID and the 30-day survival was almost half compared to non-COVID patients. Conclusion: Very old COVID patients have a different trajectory than non-COVID patients. Whether this finding is due to a decision policy with more active treatment limitation or to an inherent higher risk of death due to COVID-19 is unclear.info:eu-repo/semantics/publishedVersio

    Relationship between the Clinical Frailty Scale and short-term mortality in patients ≥ 80 years old acutely admitted to the ICU: a prospective cohort study.

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    BACKGROUND: The Clinical Frailty Scale (CFS) is frequently used to measure frailty in critically ill adults. There is wide variation in the approach to analysing the relationship between the CFS score and mortality after admission to the ICU. This study aimed to evaluate the influence of modelling approach on the association between the CFS score and short-term mortality and quantify the prognostic value of frailty in this context. METHODS: We analysed data from two multicentre prospective cohort studies which enrolled intensive care unit patients ≥ 80 years old in 26 countries. The primary outcome was mortality within 30-days from admission to the ICU. Logistic regression models for both ICU and 30-day mortality included the CFS score as either a categorical, continuous or dichotomous variable and were adjusted for patient's age, sex, reason for admission to the ICU, and admission Sequential Organ Failure Assessment score. RESULTS: The median age in the sample of 7487 consecutive patients was 84 years (IQR 81-87). The highest fraction of new prognostic information from frailty in the context of 30-day mortality was observed when the CFS score was treated as either a categorical variable using all original levels of frailty or a nonlinear continuous variable and was equal to 9% using these modelling approaches (p < 0.001). The relationship between the CFS score and mortality was nonlinear (p < 0.01). CONCLUSION: Knowledge about a patient's frailty status adds a substantial amount of new prognostic information at the moment of admission to the ICU. Arbitrary simplification of the CFS score into fewer groups than originally intended leads to a loss of information and should be avoided. Trial registration NCT03134807 (VIP1), NCT03370692 (VIP2)
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