Identificación de señales autogeneradas que afectan a la patogenicidad de Fusarium oxysporum

Fusarium oxysporum (Fo) es uno de los hongos fitopatógenos más destructivos a nivel mundial afectando a una gran variedad de cultivos vegetales, utilizados tanto como para alimentación humana, como animal. Por ello es esencial conocer cómo funciona su ciclo de reproducción y de infección, y así poder desarrollar estrategias apropiadas de contención. Ambos ciclos están regulados por una señalización autocrina de feromonas y la α-feromona, que modulan diferentes aspectos de la fisiología y patología de los hongos, entre ellos, la germinación, el quimiotropismo y el quorum sensing.En el hongo modelo S. cerevisae, Bar1 es una aspartil proteasa secretada que actúa como "barrera" y antagonista de la señalización de la α-feromona. Dado que las proteasas Bar1 de diferentes hongos (C. albicans y S. cerevisae) reconocen y tienen un sitos de corte diferentes en la α-feromona, es difícil predecir dónde podría cortar Bar1 de F. oxysporum la α-feromona en esta especie fúngica. Aquí mostramos que la proteasa Bar1 de F. oxysporum, a diferencia de las de otros hongos (C. albicans y S. cerevisae), no es secretada, tal y como se predijo a través de un estudio bioinformático y por otras evidencias experimentales.En efecto, utilizando exudados fúngicos de F. oxysporum y mutantes de ΔBar1 pudimos identificar la presencia de una proteasa secretada hasta ahora desconocida, que corta la α-feromona de F. oxysporum entre Cys2 y Thr3, pero la presencia de Bar1 no fue identificada. No se dieron los mismos cortes en la αferomona de F. oxysporum cuando se incubó directamente con la germínula del hongo. En este caso se detectó un sitio de corte adicional entre Thr3 y Trp4 cuando se utilizó germínula wt pero no en germínula de ΔBar1.Es probable que F. oxysporum, al igual que otros hongos filamentosos y a diferencia de los hongos tipo levadura, necesite anclar Bar1 a su membrana por alguna razón aún desconocida. Para entender mejor esto y el papel que desempeña una proteasa secretada aún no descrita en la señalización autocrina de F. oxysporum, serán necesarios más experimentos.<br /

Training for MIS in pediatric urology: Proposition of a structured training curriculum

Abstract In Europe there are a lot of training centers for minimally invasive surgery (MIS) but a standardized MIS training program in pediatric urology doesn't exist at the moment. We performed a literature review with the last goals to propose a structured training curriculum in MIS urology for pediatric surgeons. Pediatric urologists have to obtain a valid MIS training curriculum completing the following 4 steps: (I) Theoretical part (theoretical courses, masterclass) to acquire theoretical knowledge; (II) experimental training (simulation on pelvic trainer, virtual reality simulators, animal models, 3-D ex-vivo models) to acquire basic laparoscopic skills; (III) stages in European centers of reference for pediatric MIS urology to learn all surgery aspects; (IV) personal operative experience. At the end of the training period, the trainee would be expected to perform several MIS urological procedures independently, under supervision of an expert tutor. At the end of the training program, each center will analyze the candidate training booklet and release for each applicant a certification after an exam. We think that this MIS training program in pediatric urology may assure an integrated acquisition of basic and advanced laparoscopic skills during residency training in pediatric urology. Each European country should adopt this program so as to secure a standardized technical qualification in MIS urology for all future pediatric urologists

Selective Oxidation Catalysis: Opportunities and Challenges

This contribution discusses some aspects crucial for designing optimal and sustainable oxidation processes. The catalyst, although at the heart of the system, is only one decisive design parameter amongst many others. Indeed, an interdisciplinary approach is required to improve existing processes, but also to rationally and systematically access opportunities for oxidation research on renewable feedstock compound

Understanding Selective Oxidations

Functionalizing organic molecules is an important value-creating step throughout the entire chemical value-chain. Oxyfunctionalization of value-chain. Oxyfunctionalization of e.g. C–H or C=C bonds is one of the most important functionalization technologies used industrially. The major challenge in this field is the prevention of side reactions and/or the consecutive over-oxidation of the desired products. Despite its importance, a fundamental understanding of the intrinsic chemistry, and the subsequent design of a tailored engineering environment, is often missing. Industrial oxidation processes are indeed to a large extent based on empirical know-how. In this mini-review, we summarize some of our previous work to help to bridge this knowledge gap and elaborate on our ongoing research

Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients

Abstract Hydronephrosis is the most common presentation of ureteropelvic junction (UPJ) obstruction. We reviewed literature, collecting data from Medline, to evaluate the current status of minimally invasive surgery (MIS) approach to pyeloplasty. Since the first pyeloplasty was described in 1939, several techniques has been applied to correct UPJ obstruction, but Anderson-Hynes dismembered pyeloplasty is established as the gold standard, to date also in MIS technique. According to literature several studies underline the safety and effectiveness of this approach for both trans- and retro-peritoneal routes, with a success rate between 81-100% and an operative time between 90-228 min. These studies have demonstrated the safety and efficacy of this procedure in the management of UPJ obstruction in children. Whether better the transperitoneal, than the retroperitoneal approach is still debated. A long learning curve is needed especially in suturing and knotting

Treatment of vesico-ureteral reflux in infants and children using endoscopic approaches

Abstract Vesicoureteral reflux (VUR) represents one of the most significant risk factors for acute pyelonephritis in children. Endoscopic treatment of VUR dates back to 1981 when Matouschek first described injection of the ureteral orifice in an attempt to correct VUR. In addition, also Politano and colleagues and McDonald described successful correction of reflux using endoscopic techniques. After these reports subureteral Teflon injection (STING) came to be appreciated as a viable new way to less invasively correct one of the most common pediatric urologic problems. The technique is technically easy to perform and is usually performed as an outpatient procedure. It is performed in general anesthesia in children and may require repeat injections, particularly in patients with high-grade reflux. As for endoscopic technique, a main problem existed. The success in children with high grade reflux was less than reported for open or laparoscopic reimplant techniques. However, in the past 10 years, newer products have become available that are changing the indications for endoscopic correction. In these review, we analyzed the papers published in the literature on this topic to give to the readers an updated overview about the results of endoscopic treatment of VUR after 30-years of his first description

Aerobic Oxidation of Cyclohexane Catalyzed by Flame-Made Nano-Structured Co/SiO2 Materials

The aerobic oxidation of cyclohexane was studied at 130°C in the presence of a Co/SiO2 catalyst, synthesized by flame-spray pyrolysis. Characterization of the material indicates that at low Co-loadings, CoII is predominantly present as tetrahedral species, whereas at higher loadings also small amounts of octahedral species can be found at the surface of the agglomerated nano-particles. Catalytic experiments demonstrate high activity, causing a complete in situ deperoxidation of the intermediate cyclohexylhydroperoxide. Hot-separation and catalyst-recycle tests corroborate the heterogeneous nature of the catalys

Microvascular free-flap transfer for head and neck reconstruction in elderly patients

BACKGROUND: With the increase in life expectancy, the incidence of head and neck cancer has grown in the elderly population. Free tissue transfer has become the first choice, among all the reconstructive techniques, in these cases. The safety and success of micro vascular transfer have been well documented in the general population, but its positive results achieved in elderly patients have received less attention. METHODS: We retrospectively studied 28 patients over the age of 60 years. The aim of this paper was to study the success rate of free tissue transfer and investigate the complication incidence in this patient population. RESULTS: Twenty-eight free flaps were performed to reconstruct medium to large cervico-facial surgical defects in six years. No difference was noted between success and complication rates observed between general and elderly population. CONCLUSION: This study indicates that free-flap technique for head and neck reconstruction could be considered a safe option in elderly patients when a good pre-operative general status is present

HapX-Mediated Iron Homeostasis Is Essential for Rhizosphere Competence and Virulence of the Soilborne Pathogen Fusarium oxysporum

Soilborne fungal pathogens cause devastating yield losses and are highly persistent and difficult to control. During the infection process, these organisms must cope with limited availability of iron. Here we show that the bZIP protein HapX functions as a key regulator of iron homeostasis and virulence in the vascular wilt fungus Fusarium oxysporum. Deletion of hapX does not affect iron uptake but causes derepression of genes involved in iron-consuming pathways, leading to impaired growth under iron-depleted conditions. F. oxysporum strains lacking HapX are reduced in their capacity to invade and kill tomato (Solanum lycopersicum) plants and immunodepressed mice. The virulence defect of ΔhapX on tomato plants is exacerbated by coinoculation of roots with a biocontrol strain of Pseudomonas putida, but not with a siderophore-deficient mutant, indicating that HapX contributes to iron competition of F. oxysporum in the tomato rhizosphere. These results establish a conserved role for HapX-mediated iron homeostasis in fungal infection of plants and mammals