1,687 research outputs found

    Bub1 as a recruitment platform for Spindle Assembly Checkpoint components

    Get PDF
    Motivation: The Spindle Assembly Checkpoint (SAC) is a safeguard mechanism conserved in all the eukaryotes that ensures the correct chromosome segregation in mitosis by preventing the premature mitotic exit in condition of unattached kinetochores. SAC defects lead to chromosome mis-segregation provoking aneuploidies that has been widely associated with cancer. Kinase Bub1 is a key player in SAC function because it maintains a proper centromeric cohesion and serves as a platform for other SAC components such as Mad1, Mad2 and Mad3. In this study, we are characterizing a bub1 mutant allele which exhibits an impaired SAC function. The phenotype shown by this mutant has not been previously described. This mutant can provide new insights about the Bub1-dependent recruitment of SAC components to the kinetochores and the mechanism of mitosis arrest.Methods: We made use of live imaging techniques to study SAC function by using GFP-tagged alleles of the main SAC components (like Mad1, Mad2 and Mad3), comparing the wild type background versus the bub1 mutant allele. Furthermore, we have used a cold sensitive tubulin mutant that allows us to test SAC activity; in response to microtubules damage induced by this mutant, cells activate the SAC and arrest in metaphase. We have also tested Bub1 protein levels in a wild-type and in the Bub1-mutant by Western Blot. Finally, we are performing a two-hybrid screening using a S. pombe library-strain to detect differences in the interactome of the Bub1-mutant compared with the wild-type. Results: We have demonstrated that in the Bub1-mutant background, Mad1 correctly localizes at the kinetochores meanwhile Mad2 does not. Bub1 protein levels turned out to be quite similar in both strain. Additionally, we have observed that the SAC defects notice in the Bub1-mutant in the cold sensitive background partially phenocopies the one seen in the Bub1-deleted cells.Conclusions: Our Bub1-mutant is unable to maintain a proper metaphase block in the cold-sensitive tubulin background and exhibit a SAC failure. We are working in a model where Bub1 could be regulating SAC activity by promoting Mad2 recruitment to kinetochores

    Activity/inactivity circadian rhythm shows high similarities between young obesity-induced rats and old rats

    Get PDF
    The objective of the present study was to compare differences between elderly rats and young obesity-induced rats in their activity/inactivity circadian rhythm. The investigation was motivated by the differences reported previously for the circadian rhythms of both obese and elderly humans (and other animals), and those of healthy, young or mature individuals. Three groups of rats were formed: a young control group which was fed a standard chow for rodents; a young obesity-induced group which was fed a high-fat diet for four months; and an elderly control group with rats aged 2.5 years that was fed a standard chow for rodents. Activity/inactivity data were registered through actimetry using infrared actimeter systems in each cage to detect activity. Data were logged on a computer and chronobiological analysis were performed. The results showed diurnal activity (sleep time), nocturnal activity (awake time), amplitude, acrophase, and interdaily stability to be similar between the young obesity-induced group and the elderly control group, but different in the young control group. We have concluded that obesity leads to a chronodisruption status in the body similar to the circadian rhythm degradation observed in the elderly

    Interstitial Cells of Cajal and Enteric Nervous System in Gastrointestinal and Neurological Pathology, Relation to Oxidative Stress

    Get PDF
    The enteric nervous system (ENS) is organized into two plexuses-submucosal and myenteric-which regulate smooth muscle contraction, secretion, and blood flow along the gastrointestinal tract under the influence of the rest of the autonomic nervous system (ANS). Interstitial cells of Cajal (ICCs) are mainly located in the submucosa between the two muscle layers and at the intramuscular level. They communicate with neurons of the enteric nerve plexuses and smooth muscle fibers and generate slow waves that contribute to the control of gastrointestinal motility. They are also involved in enteric neurotransmission and exhibit mechanoreceptor activity. A close relationship appears to exist between oxidative stress and gastrointestinal diseases, in which ICCs can play a prominent role. Thus, gastrointestinal motility disorders in patients with neurological diseases may have a common ENS and central nervous system (CNS) nexus. In fact, the deleterious effects of free radicals could affect the fine interactions between ICCs and the ENS, as well as between the ENS and the CNS. In this review, we discuss possible disturbances in enteric neurotransmission and ICC function that may cause anomalous motility in the gut.info:eu-repo/semantics/publishedVersio

    Antimicrobial activity of the fiber produced by “pochote” Ceiba aesculifolia subsp. parvifolia

    Get PDF
    Background: The cotton-like fiber from the fruit of Pochote (Ceiba aesculifolia subsp. parvifolia) can be applied to wounds for healing purposes. As microorganisms can infect wounds and hamper the wound healing process, the aim of this study was to determine the antimicrobial activity and chemical composition of the methanolic extract of Pochote fiber.Materials and Methods: The methanolic extract was tested against bacteria and fungi. For bacteria, the Kirby-BaĂŒer disc diffusion and broth dilution methods were employed to determine the MIC and MBC. In addition, bactericidal kinetic curves were generated. The antifungal activity was determined by the radial diffusion method. The antioxidant activity, total phenolic content, and the flavonoid content were determined. Bioassay guided fractionation was also performed.Results: The methanolic extract showed activity against Enterococcus faecalis, Staphylococcus aureus and Vibrio cholerae (cc). The tested V. cholerae strains were the most sensitive strains, and exhibited a clear CFU size reduction from the bactericidal kinetic curves. The methanolic extract had activity against T. mentagrophytes and R. lilacina. The antioxidant activity (SC50= 36.42 ÎŒg/mL) was related to the total phenolic (74.4 mg eAG/g) and flavonoid content (21.982 mg (eQ)/g). The bioassay guided fractionation results suggested that the antimicrobial properties of the extract may act through synergism because the total extract had higher activity against bacteria compared to the collected fractions.Conclusion: This study scientifically validates the application of the fruit fiber from Pochote as a part of a traditional medicine approach to alleviate infections caused by bacteria and fungi.Keywords: antimicrobial, Ceiba, Bombacaceae, fruit fib

    On the structure of acyclic binary relations

    Get PDF
    We investigate the structure of acyclic binary relations from different points of view. On the one hand, given a nonempty set we study real-valued bivariate maps that satisfy suitable functional equations, in a way that their associated binary relation is acyclic. On the other hand, we consider acyclic directed graphs as well as their representation by means of incidence matrices. Acyclic binary relations can be extended to the asymmetric part of a linear order, so that, in particular, any directed acyclic graph has a topological sorting.This work has been partially supported by the research projects MTM2012-37894-C02-02, TIN2013-47605-P, ECO2015-65031-R, MTM2015-63608-P (MINECO/FEDER), TIN2016-77356-P and the Research Services of the Public University of Navarre (Spain)

    Supernatants from lymphocytes stimulated with Bacillus Calmette-Guerin can modify the antigenicity of tumours and stimulate allogeneic T-cell responses

    Get PDF
    BACKGROUND: Reduced expression of class 1 human leucocyte antigens (HLA1) is often a mechanism by which tumours evade surveillance by the host immune system. This is often associated with an immune function that is unable to mount appropriate responses against disease, which can result in a state that favours carcinogenesis. METHODS: In the current study, we have explored the effects of Bacillus Calmette-Guerin (BCG) on the cytokine output of leucocytes, which is a key determinant in generating antitumour action, and have also assessed the effect of these cytokine cocktails on HLA1 expression in solid tumour cell lines. RESULTS: BCG potently activated a broad range of leucocytes, and also enhanced the production of cytokines that were Th(1)-predominant. Supernatants from BCG-treated leucocytes significantly increased the expression of HLA1 on the surface of cancer cell lines, which correlated with increased cytolytic T-cell activity. We also showed that the increased HLA1 expression was associated with activation of intracellular signalling pathways, which was triggered by the increases in the Th(1)-cytokines interferon-γ and tumour necrosis factor-α, as counteracting their effects negated the enhancement. CONCLUSION: These studies reaffirm the role of BCG as a putative immunotherapy through their cytokine-modifying effects on leucocytes and their capacity to enhance tumour visibility

    Resource Competition Triggers the Co-Evolution of Long Tongues and Deep Corolla Tubes

    Get PDF
    Background: It is normally thought that deep corolla tubes evolve when a plant’s successful reproduction is contingent on having a corolla tube longer than the tongue of the flower’s pollinators, and that pollinators evolve ever-longer tongues because individuals with longer tongues can obtain more nectar from flowers. A recent model shows that, in the presence of pollinators with long and short tongues that experience resource competition, coexisting plant species can diverge in corolla-tube depth, because this increases the proportion of pollen grains that lands on co-specific flowers. Methodology/Principal Findings: We have extended the model to study whether resource competition can trigger the coevolution of tongue length and corolla-tube depth. Starting with two plant and two pollinator species, all of them having the same distribution of tongue length or corolla-tube depth, we show that variability in corolla-tube depth leads to divergence in tongue length, provided that increasing tongue length is not equally costly for both species. Once the two pollinator species differ in tongue length, divergence in corolla-tube depth between the two plant species ensues. Conclusions/Significance: Co-evolution between tongue length and corolla-tube depth is a robust outcome of the model, obtained for a wide range of parameter values, but it requires that tongue elongation is substantially easier for one pollinator species than for the other, that pollinators follow a near-optimal foraging strategy, that pollinators experienc

    Risk of upper gastrointestinal bleeding and perforation associated with low-dose aspirin as plain and enteric-coated formulations

    Get PDF
    BACKGROUND: The use of low-dose aspirin has been reported to be associated with an increased risk of upper gastrointestinal complications (UGIC). The coating of aspirin has been proposed as an approach to reduce such a risk. To test this hypothesis, we carried out a population based case-control study. METHODS: We identified incident cases of UGIC (bleeding or perforation) aged 40 to 79 years between April 1993 to October 1998 registered in the General Practice Research Database. Controls were selected randomly from the source population. Adjusted estimates of relative risk (RR) associated with current use of aspirin as compared to non use were computed using unconditional logistic regression. RESULTS: We identified 2,105 cases of UGIC and selected 11,500 controls. Among them, 287 (13.6%) cases and 837 (7.3%) controls were exposed to aspirin, resulting in an adjusted RR of 2.0 (1.7-2.3). No clear dose-effect was found within the range of 75-300 mg. The RR associated with enteric-coated formulations (2.3, 1.6-3.2) was similar to the one of plain aspirin (1.9, 1.6-2.3), and no difference was observed depending on the site. The first two months of treatment was the period of greater risk (RR= 4.5, 2.9-7.1). The concomitant use of aspirin with high-dose NSAIDs greatly increased the risk of UGIC (13.3, 8.5-20.9) while no interaction was apparent with low-medium doses (2.2, 1.0-4.6). CONCLUSIONS: Low-dose aspirin increases by twofold the risk of UGIC in the general population and its coating does not modify the effect. Concomitant use of low-dose aspirin and NSAIDs at high doses put patients at a specially high risk of UGIC

    VALORACIÓN NUTRICIONAL EN LACTANTES DE ENTRE 8 A 12 MESES DE VIDA

    Get PDF
    <!-- /* Font Definitions */ @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-1610611985 1107304683 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman","serif"; mso-fareast-font-family:"Times New Roman";} .MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:10.0pt; mso-ansi-font-size:10.0pt; mso-bidi-font-size:10.0pt;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Objective: The aim of this study was to analyze the diet of infants that receive supplemental breast milk, by way of a two-week survey on nutrition consumption, completed by the parents of infants between 8 and 12 months of age from the province of Badajoz, Spain. Dial® software was used for the nutritional analysis and quantification.  Results: The analysis of the daily diet shows in this study that it is repetitive and equivalent in all infants during this age interval, which is made: at the beginning of the day for follow-on milk and infantile cereals, followed by vegetable baby food with meat, fruit baby food, and finally at the end of the day follow-on milk and cereals again. Indicating that energy intake was correct (1355 ± 252.93 kcal), highlighting that regarding macronutrients the protein percentage intake (44.40 ± 5.014 g/day) is high compared to the daily recommendations. In addition, it presents a repetitive and constant dietary pattern throughout all the participants. Conclusion: In our study population with supplementary feeding, the diet of these infants between 8 and 12 months of age is suited to the daily energy needs for that period of growth, as well as an inadequate daily ingestion on proteins. .Objetivo: En este trabajo se ha tratado de conocer profundamente la alimentación infantil con lactancia complementaria, a través de un cuestionario de consumo de alimentos de dos semanas de duración, el cual fue completado por los padres de lactantes de entre 8 y 12 meses, de la provincia de Badajoz. Para su análisis y cuantificación nutricional se manejó la aplicación informática Dial©.  Resultados: El análisis de la dieta diaria mostró en su estudio que es repetitiva y equivalente en todos los lactantes durante este intervalo de edad, la cual estaba constituida: al inicio del día por leches de continuación y cereales infantiles, continuando con potitos de verduras con carne, potitos de fruta y por último al final del día, de nuevo leches de continuación y cereales infantiles. Indicar que la ingesta energética era correcta (1355 ± 252,93 kcal), destacando que en lo que respecta a macronutrientes el porcentaje en proteínas se encontró elevado (44,40 ± 5,014 g) frente a las recomendaciones diarias. Además de presentar un patrón dietético repetitivo y constante en toda la población. Conclusión: En la población estudiada con lactancia complementaria, la dieta de estos lactantes entre 8 y 12 meses de vida se adecua a las necesidades energéticas diarias para dicho periodo de crecimiento, pero mantienen una inadecuada ingesta diaria de proteínas
    • 

    corecore