57 research outputs found

    A limit on the evolutionary rescue of an Antarctic bacterium from rising temperatures

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    Climate change is gradual, but it can also cause brief extreme heat waves that can exceed the upper thermal limit of any one organism. To study the evolutionary potential of upper thermal tolerance, we evolved the cold-adapted Antarctic bacterium Pseudoalteromonas haloplanktis to survive at 30°C, beyond its ancestral thermal limit. This high-temperature adaptation occurred rapidly and in multiple populations. It involved genomic changes that occurred in a highly parallel fashion and mitigated the effects of protein misfolding. However, it also confronted a physiological limit, because populations failed to grow beyond 30°C. Our experiments aimed to facilitate evolutionary rescue by using a small organism with large populations living at temperatures several degrees below their upper thermal limit. Larger organisms with smaller populations and living at temperatures closer to their upper thermal tolerances are even more likely to go extinct during extreme heat waves

    Efecto de la terapia manual en el síndrome del latigazo cervical

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    Introducción: El síndrome del latigazo cervical es una patología muy común altamente relacionada con los accidentes de tráfico. Puede presentarse de varias formas, cuyos signos y síntomas son distintos en cada caso, por ello no existe un solo tipo de tratamiento. El tratamiento fisioterápico, que incluyen las terapias manuales, es fundamental para la mejoría de estos pacientes. Objetivo: El objetivo de este trabajo es conocer la utilidad de las diferentes técnicas manuales, utilizadas por fisioterapia, en el tratamiento del síndrome del latigazo cervical, y analizar la efectividad de las diferentes terapias manuales en combinación con otras técnicas utilizadas, realizadas por fisioterapia, en el tratamiento del síndrome del latigazo cervical. Material y métodos: Se han realizado distintas búsquedas bibliográficas en las bases de datos Pubmed, Physiotherapy evidence database (PEDro), y la Biblioteca Cochrane Plus, utilizando también Google Scholar a fin de obtener aquellos artículos a texto completo que no se encontraban disponibles en las anteriores bases de datos. Para realizar las búsquedas empleamos las palabras clave “whiplash”, “manual therapy”, “mobilization”, “cervical manipulation”, “physiotherapy” y “physical therapy”. Todas fueron combinadas con los operadores booleanos AND y OR. Para reducir la búsqueda se añadieron una serie de límites como el tipo de estudio, fecha de publicación y el idioma. Además se realizaron, mediante las escalas de PEDro y de Jadad, la valoración de la evidencia y la calidad metodológica de cada artículo. Resultados: Se encontraron un total de 208 artículos en las diferentes bases de datos que habíamos usado, descartando 201 por no cumplir los criterios de inclusión, además de encontrarse duplicados. Finalmente fueron válidos 7 para la realización de este trabajo. Conclusiones: En el tratamiento del latigazo cervical las manipulaciones vertebrales de manera aislada, son eficaces a corto plazo. Sin embargo, no existe demasiada evidencia científica por la escasez de información sobre este tema. La terapia manual es mucho más efectiva si se realiza en combinación con otros tratamientos fisioterápicos como los ultrasonidos, ejercicios activos, estiramientos musculares, y terapia multimodal que engloba el masaje y la electroterapia.Grado en Fisioterapi

    Characterization of a new toxin from the entomopathogenic fungus Metarhizium anisopliae: the ribotoxin anisoplin

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    Metarhizium anisopliae is an entomopathogenic fungus relevant in biotechnology with applications like malaria vector control. Studies of its virulence factors are therefore of great interest. Fungal ribotoxins are toxic ribonucleases with extraordinary efficiency against target ribosomes and suggested as potential insecticides. Here, we describe this ribotoxin characteristic activity in M. anisopliae cultures. Anisoplin has been obtained as a recombinant protein and further characterized. It is structurally similar to hirsutellin A, the ribotoxin from the entomopathogen Hirsutella thompsonii. Moreover, anisoplin shows the ribonucleolytic activity typical of ribotoxins and cytotoxicity against insect cells. How Metarhizium uses this toxin and possible applications are on perspective

    Minimized natural versions of fungal ribotoxins show improved active site plasticity

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    Fungal ribotoxins are highly specific extracellular RNases which cleave a single phosphodiester bond at the ribosomal sarcin-ricin loop, inhibiting protein biosynthesis by interfering with elongation factors. Most ribotoxins show high degree of conservation, with similar sizes and amino acid sequence identities above 85%. Only two exceptions are known: Hirsutellin A and anisoplin, produced by the entomopathogenic fungi Hirsutella thompsonii and Metarhizium anisopliae, respectively. Both proteins are similar but smaller than the other known ribotoxins (130 vs 150 amino acids), displaying only about 25% sequence identity with them. They can be considered minimized natural versions of their larger counterparts, best represented by α-sarcin. The conserved α-sarcin active site residue Tyr48 has been replaced by the geometrically equivalent Asp, present in the minimized ribotoxins, to produce and characterize the corresponding mutant. As a control, the inverse anisoplin mutant (D43Y) has been also studied. The results show how the smaller versions of ribotoxins represent an optimum compromise among conformational freedom, stability, specificity, and active-site plasticity which allow these toxic proteins to accommodate the characteristic abilities of ribotoxins into a shorter amino acid sequence and more stable structure of intermediate size between that of other nontoxic fungal RNases and previously known larger ribotoxins

    Fungal Ribotoxins

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    Fungal ribotoxins constitute a family of extracellular ribonucleases with exquisite specificity against rRNA (ribonucleic acid). They induce apoptotic death of cells after inhibiting protein translation. Ribosomes become functionally incompetent because ribotoxins cleave one single phosphodiester bond, located at a unique and universally conserved loop, needed for elongation factors function. As secreted proteins, ribotoxins need to cross the membrane of their target cells in order to exert their catalytic activity, and they do it without receptor mediation. Using lipid model systems, it has been shown that they are able to enter cells with membranes enriched in acidic phospholipids. Both membrane-interacting and ribosomal-recognition activities are characterised by distinct structural features. Even though the natural function of ribotoxins is not known yet, their production by entomopathogenic fungi has suggested their insecticidal role. After decades of detailed study, the biotechnological potential of ribotoxins in pest control and as antitumour agents is becoming evident

    Involvement of loops 2 and 3 of alpha-sarcin on its ribotoxic activity

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    Ribotoxins are a family of fungal ribosome-inactivating proteins displaying highly specific ribonucleolytic activity against the sarcin/ricin loop (SRL) of the larger rRNA, with a-sarcin as its best-characterized member. Their toxicity arises from the combination of this activity with their ability to cross cell membranes. The involvement of a-sarcin's loops 2 and 3 in SRL and ribosomal proteins recognition, as well as in the ribotoxin-lipid interactions involving cell penetration, has been suggested some time ago. In the work presented now different mutants have been prepared in order to study the role of these loops in their ribonucleolytic and lipid-interacting properties. The results obtained confirm that loop 3 residues Lys 111, 112, and 114 are key actors of the specific recognition of the SRL. In addition, it is also shown that Lys 114 and Tyr 48 conform a network of interactions which is essential for the catalysis. Lipid-interaction studies show that this Lys-rich region is indeed involved in the phospholipids recognition needed to cross cell membranes. Loop 2 is shown to be responsible for the conformational change which exposes the region establishing hydrophobic interactions with the membrane inner leaflets and eases penetration of ribotoxins target cells

    The ribotoxin α-sarcin can cleave the sarcin/ricin loop on late 60S pre-ribosomes

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    The ribotoxin α-sarcin belongs to a family of ribonucleases that cleave the sarcin/ricin loop (SRL), a critical functional rRNA element within the large ribosomal subunit (60S), thereby abolishing translation. Whether α-sarcin targets the SRL only in mature 60S subunits remains unresolved. Here, we show that, in yeast, α-sarcin can cleave SRLs within late 60S pre-ribosomes containing mature 25S rRNA but not nucleolar/nuclear 60S pre-ribosomes containing 27S pre-rRNA in vivo. Conditional expression of α-sarcin is lethal, but does not impede early pre-rRNA processing, nuclear export and the cytoplasmic maturation of 60S pre-ribosomes. Thus, SRL-cleaved containing late 60S pre-ribosomes seem to escape cytoplasmic proofreading steps. Polysome analyses revealed that SRL-cleaved 60S ribosomal subunits form 80S initiation complexes, but fail to progress to the step of translation elongation. We suggest that the functional integrity of a α-sarcin cleaved SRL might be assessed only during translation.Spanish Ministry of Economy and Competitiveness MINECO and the European Union ERFD program [BFU2012-32404] to A.M.P., [BFU2016-75352-P

    Two-center experience comparing the use of the FLOT4 and CROSS schemes for patients with gastric, esophageal, and gastroesophageal junction adenocarcinoma

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    Introduction. Gastric (GAD), gastroesophageal junction (GEJA), and esophageal adenocarcinoma (EAD) share pathophysiological features. At localized stages, FLOT is used perioperatively for the treatment of GAD and GEJA and CROSS for EAD and some GEJA. Although both therapies have been compared with MAGIC, comparative randomized data on FLOT and CROSS are not yet available. Material andmethods. We retrospectively analyzed and compared 40 patients treated with FLOT and 16 patients treated with CROSS in terms of clinical features and neoadjuvant, surgical, adjuvant, and survival outcomes. Results. At the time of analysis, 65% of patients treated with FLOT4 and 56.3% with CROSS remained in complete remission. Those who progressed after FLOT4 did so mainly at the peritoneal level (25%) and after CROSS at the bone, lymph node, and peritoneal levels (12.5% respectively). Six patients (37.5%) died after CROSS (median OS of 17.5 months; 95% CI 2–41) and 10 (25%) after FLOT4 (median OS 16.5 months; 95% CI 11–22). For the living patients, the median numbers of months from diagnosis to the follow-up cutoff date were 47.5 (95% CI 11–67) and 27 (95% CI 14–44) for CROSS and FLOT4, respectively. There were no significant differences in median OS estimated by Kaplan Meier analysis [FLOT4: 50 ± 4.6 months (95% CI 40.9–59.2); CROSS: 51.2 ± 7 months (95% CI 37.4–65.0; p = 0.79)].  Conclusions. Although we obtained lower pCR rates; TNM downstaging after neoadjuvant therapy, R0 rates, tolerance, PFS, and OS were similar in both groups and comparable with trial results. The adjuvant compliance rate was high with FLOT4. CROSS allows sequencing with nivolumab in PD-L1+ tumors

    Restricción por HLA de clase II de la respuesta de anticuerpos IgE frente al antígeno principal del pólen del olivo (Ole e I)

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    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Deparatamento de Biología Molecular. Fecha de lectura: 20-5-199

    Restriccion por HLA de clase 2. de la respuesta de anticuerpos IgE frente al antigeno principal del polen del olivo

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    Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai
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