N-Heterocyclic Carbene Gold Complexes Active in Hydroamination and Hydration of Alkynes

Until the year 2000, gold compounds were considered catalytically inert. Subsequently, it was found that they are able to promote the nucleophilic attack on unsaturated substrates by forming an Au-pi-system. The main limitation in the use of these catalytic systems is the ease with which they decompose, which is avoided by stabilization with an ancillary ligand. N-heterocyclic carbenes (NHCs), having interesting sigma-donor capacities, are able to stabilize the gold complexes (Au (I/III) NHC), favoring the exploration of their catalytic activity. This review reports the state of the art (years 2007-2022) in the nucleophilic addition of amines (hydroamination) and water (hydration) to the terminal and internal alkynes catalyzed by N-heterocyclic carbene gold (I/III) complexes. These reactions are particularly interesting both because they are environmentally sustainable and because they lead to the production of important intermediates in the chemical and pharmaceutical industry. In fact, they have an atom economy of 100%, and lead to the formation of imines and enamines, as well as the formation of ketones and enols, all important scaffolds in the synthesis of bioactive molecules, drugs, heterocycles, polymers, and bulk and fine chemicals

Impact of therapeutic choices on outcome of osteomyelitis caused by MRSA

Fifty-four patients with chronic osteomyelitis sustained by methicillin-resistant staphylococcus were treated with daptomycin, linezolid, or teicoplanin and observed over time. Median time to CRP normalization was 7 weeks for daptomycin, 8 weeks for linezolid, and 12 weeks for teicoplanin (X2 =14.1; p < 0.001). Cure rate (intention to treat analysis) was 83% for the cases receiving teicoplanin, 77% for those receiving linezolid and 92% for those receiving daptomycin. We conclude that daptomycin and linezolid have to be considered at least equivalent to teicoplanin for the treatment of MRSA osteomyelitis

National audit of post-operative management in spinal surgery

BACKGROUND: There is some evidence from a Cochrane review that rehabilitation following spinal surgery may be beneficial. METHODS: We conducted a survey of current post-operative practice amongst spinal surgeons in the United Kingdom in 2002 to determine whether such interventions are being included routinely in the post-operative management of spinal patients. The survey included all surgeons who were members of either the British Association of Spinal Surgeons (BASS) or the Society for Back Pain Research. Data on the characteristics of each surgeon and his or her current pattern of practice and post-operative care were collected via a reply-paid postal questionnaire. RESULTS: Usable responses were provided by 57% of the 89 surgeons included in the survey. Most surgeons (79%) had a routine post-operative management regime, but only 35% had a written set of instructions that they gave to their patients concerning this. Over half (55%) of surgeons do not send their patients for any physiotherapy after discharge, with an average of less than two sessions of treatment organised by those that refer for physiotherapy at all. Restrictions on lifting, sitting and driving showed considerable inconsistency both between surgeons and also within the recommendations given by individual surgeons. CONCLUSION: Demonstrable inconsistencies within and between spinal surgeons in their approaches to post-operative management can be interpreted as evidence of continuing and significant uncertainty across the sub-speciality as to what does constitute best care in these areas of practice. Conducting further large, rigorous, randomised controlled trials would be the best method for obtaining definitive answers to these questions

Damages of the tibial post in constrained total knee prostheses in the early postoperative course – a scanning electron microscopic study of polyethylene inlays

<p>Abstract</p> <p>Background</p> <p>Investigation of the risk of fracture of the polyethylene (PE) inlay in constrained total knee prostheses.</p> <p>Methods</p> <p>Three unused and seven polyethylene inlays that had been implanted in a patient's knee for an average of 25.4 months (min 1.1 months, max 50.2 months) were investigated using scanning electron microscopy (SEM). All inlays were of the same type and size (Genesis II constrained, Smith & Nephew). The PE surface at the transition from the plateau to the post was analyzed.</p> <p>Results</p> <p>The unused inlays had fissure-free surfaces. All inlays that had been implanted in a patient's knee already had distinct fissures at the front and backside of the post.</p> <p>Conclusion</p> <p>The fissures of the transition from the plateau to the post indicated a loading-induced irreversible mechanical deformation and possibly cause the fracture of the inlay.</p

A novel role for RecA under non-stress: promotion of swarming motility in Escherichia coli K-12

BACKGROUND: Bacterial motility is a crucial factor in the colonization of natural environments. Escherichia coli has two flagella-driven motility types: swimming and swarming. Swimming motility consists of individual cell movement in liquid medium or soft semisolid agar, whereas swarming is a coordinated cellular behaviour leading to a collective movement on semisolid surfaces. It is known that swimming motility can be influenced by several types of environmental stress. In nature, environmentally induced DNA damage (e.g. UV irradiation) is one of the most common types of stress. One of the key proteins involved in the response to DNA damage is RecA, a multifunctional protein required for maintaining genome integrity and the generation of genetic variation. RESULTS: The ability of E. coli cells to develop swarming migration on semisolid surfaces was suppressed in the absence of RecA. However, swimming motility was not affected. The swarming defect of a ΔrecA strain was fully complemented by a plasmid-borne recA gene. Although the ΔrecA cells grown on semisolidsurfaces exhibited flagellar production, they also presented impaired individual movement as well as a fully inactive collective swarming migration. Both the comparative analysis of gene expression profiles in wild-type and ΔrecA cells grown on a semisolid surface and the motility of lexA1 [Ind-] mutant cells demonstrated that the RecA effect on swarming does not require induction of the SOS response. By using a RecA-GFP fusion protein we were able to segregate the effect of RecA on swarming from its other functions. This protein fusion failed to regulate the induction of the SOS response, the recombinational DNA repair of UV-treated cells and the genetic recombination, however, it was efficient in rescuing the swarming motility defect of the ΔrecA mutant. The RecA-GFP protein retains a residual ssDNA-dependent ATPase activity but does not perform DNA strand exchange. CONCLUSION: The experimental evidence presented in this work supports a novel role for RecA: the promotion of swarming motility. The defective swarming migration of ΔrecA cells does not appear to be associated with defective flagellar production; rather, it seems to be associated with an abnormal flagellar propulsion function. Our results strongly suggest that the RecA effect on swarming motility does not require an extensive canonical RecA nucleofilament formation. RecA is the first reported cellular factor specifically affecting swarming but not swimming motility in E. coli. The integration of two apparently disconnected biologically important processes, such as the maintenance of genome integrity and motility in a unique protein, may have important evolutive consequences

The Eagle And The Starlings: Galileo\u27s Argument For The Autonomy Of Science - How Pertinent Is It Today?

After Galileo\u27s argument for the autonomy of science is analysed and adapted to take into account later developments of scientific practices, we conclude that, in the final analysis, it is not compelling. Nevertheless, Galileo\u27s argument still provides a useful point of reference, for aspects of it can be interpreted to anticipate central components of the often acclaimed ideal of science as value free, so that appraising it contributes to the larger purpose of exploring how well that ideal stands up today. Finally, we will argue that residue from Galileo\u27s struggle with the Church remains with us, making it difficult to identify the conditions that would need to be put into place today for any robust sense of the autonomy of science to be defensible. (C) 2011 Elsevier Ltd. All rights reserved

A Águia E Os Estorninhos: Galileu E A Autonomia Da Ciência

The idea that science is value free can be traced back to the emergence of the distinction between fact and value in the 17th century. It can be considered to have three components: impartiality, neutrality and autonomy. We show that important parts of these component ideas were developed and defended by Galileo, principally in his letters to Castelli and to Grand Duchess Cristina and in his books The Assayer and Two Chief World Systems. Galileo\u27s argument for autonomy is particularly powerful and, although lacking the generality introduced in later arguments (since his principal concern was to win autonomy for science from the authority of the Church), it remains at the core of all subsequent defenses of the autonomy of science. This argument is based on three suppositions: that scientific understanding is subject to criteria that are independent of the Church\u27s authority and of any value perspective, that scientists have cultivated the virtues of the scientific ethos , and that (because they use different languages — the two books argument) there cannot be contradiction between properly made scientific judgments and declarations of the Church. Finally some limitations of Galileo\u27s arguments are indicated but not developed.A idéia de que a ciência é livre de valores pode ser reconduzida à emergência da distinção entre fato e valor no século XVII. Pode–se considerar que essa idéia tem três componentes: imparcialidade, neutralidade e autonomia. Mostramos que partes importantes dessas idéias componentes foram desenvolvidas e defendidas por Galileu, principalmente em suas cartas a Castelli e à grã–duquesa Cristina e em seus livros O ensaiador e Diálogo sobre os dois máximos sistemas do mundo. O argumento de Galileu em favor da autonomia é particularmente poderoso e, embora não tenha a generalidade introduzida por argumentos posteriores (uma vez que seu principal objetivo era o de garantir a autonomia da ciência com relação à autoridade da Igreja), permanece no cerne de todas as defesas subseqüentes da autonomia da ciência. Esse argumento está baseado em três suposições: que o entendimento científico está sujeito a critérios que são independentes da autoridade da Igreja e de qualquer perspectiva de valor; que os cientistas cultivam as virtudes do ethos científico ; e que (porque usam linguagens diferentes — o argumento dos dois livros ) não pode existir contradição entre os juízos científicos apropriados e as declarações da Igreja. Finalmente, algumas limitações dos argumentos de Galileu são indicadas, sem serem desenvolvidas

Isolamento microbiologico, terapia orale e comorbidità influenzano l'outcome delle PJI sottoposte a two-stage

Gli autori, sulla base dei propri risultati, mostrano che l'isolamento microbiologico del germe responsabile dell'infezione e la possibilità di utilizzare una terapia antibiotica orale influenzano positivamente l'outcome delle infezioni artroprotesiche sottoposte a reimpianto two-stage. Le comorbidità rappresentano viceversa un predittore prognostico negativo

Continuous Antibiotic Therapy Can Reduce Recurrence of Prosthetic Joint Infection in Patients Undergoing 2-Stage Exchange

Background: Reimplantation microbiology and serum C-reactive protein have low diagnostic accuracy in predicting recurrence in patients with prosthetic joint infection (PJI) undergoing 2-stage exchange. We aimed at identifying factors relating to failure and comparing effect of continuous antibiotic therapy versus a holiday antibiotic period pre-reimplantation. Methods: This observational study included patients with PJI undergoing 2-stage exchange. Group A patients did not discontinue antibiotic treatment pre-reimplantation; in group B patients, antibiotic treatment was followed with 2 weeks of holiday antibiotic period pre-reimplantation. We defined cure as absence of recurrence for 96 weeks post-reimplantation. Statistical analyses were performed using Mann-Whitney U test, Fisher exact test, and multivariate analysis. Results: We evaluated 196 patients with PJI (median age, 66 years [interquartile range, 59-72], 91 [46%] males). Comorbidity was reported in 77 (39%), and microbiologic evidence was obtained in 164 (84%). Staphylococcus aureus was isolated in 63 of 164 (38%) patients; coagulase-negative staphylococci were isolated in 71 of 164 (43%). Favorable outcome was achieved for 169 (86%) patients (91% and 79% in groups A and B, respectively). No immunocompromise (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.3-7.3; P =.04), a positive culture (OR, 3.96; 95% CI, 1.55-10.19; P =.02), and no antibiotic discontinuation (OR, 3.32; 95% CI, 1.3-8.44; P =.02) predicted favorable outcome using multivariate analysis. Conclusion: Treatment with continuous antibiotic therapy ameliorated success rate, permitting a better outcome in immunocompromised and reducing the time to reimplantation. Continuous antibiotic therapy can be considered a valid option for the treatment of patients with PJI undergoing 2-stage exchange. Level of evidence: Therapeutic level II