351 research outputs found
Structural implications of the DFD-in domain in computer-aided molecular design of MAP kinase interacting kinase 2 inhibitors.
Protein translation is a key process on cell development and proliferation that is often deregulated in cancer. MAP kinase interacting kinases 1 and 2(Mnk1/2) play a pivotal role in regulating the capdependent translation through phosphorylation ofeIF4E transcription factor. Thus, Mnk1/2 targeting have been proposed as a novel therapeutic strategy that would minimize side-effects in contrast to other therapies. For this reason, there is a growing interestin designing in silico new Mnk1/2 inhibitors which demands from reliable structural models. Interestingly,the catalytic domain of Mnk proteins are characterized by a DFD motif instead of the characteristicDFG motif of other kinases. However, Mnk2 structural models described in literature are DFG mutated and do not contain the activation loop. Molecular design techniques have been applied to obtain a structural model of the full wild type Mnk2 protein including the activation loop. The effect of the loop on the interaction mechanism of well-known ligands has been evaluated. Obtained results suggest that the presence of the activation loop is determinant for the correct prediction of the active site and it is essential for the design of new inhibitors
Lipoma of the Uterine Corpus: Exceptional Eventuality Combined with an Ovarian Thecoma
Uterine lipomas are very uncommon with symptoms that are similar to leiomyomas. Their diagnosis is always histological although some radiological methods may suggest their existence prior to surgery. They are sometimes associated with endometrial pathology, but there are no previous reported cases related to ovarian thecoma. Their prognosis is excellent. Clinical, radiological, morphologic, and immunohistochemical findings are shown which correspond to uterine lipoma associated with endometrial polyps and ovarian thecoma
Neuroglia at the crossroads of homoeostasis, metabolism and signalling: evolution of the concept
Ever since Rudolf Virchow in 1858 publicly announced his apprehension of neuroglia being a true connective substance, this concept has been evolving to encompass a heterogeneous population of cells with various forms and functions. We briefly compare the 19th–20th century perspectives on neuroglia with the up-to-date view of these cells as an integral, and possibly integrating, component of brain metabolism and signalling in heath and disease. We conclude that the unifying property of otherwise diverse functions of various neuroglial cell sub-types is to maintain brain homoeostasis at different levels, from whole organ to molecular
Role of transport performance on neuron cell morphology
The compartmental model is a basic tool for studying signal propagation in
neurons, and, if the model parameters are adequately defined, it can also be of
help in the study of electrical or fluid transport. Here we show that the input
resistance, in different networks which simulate the passive properties of
neurons, is the result of an interplay between the relevant conductances,
morphology and size. These results suggest that neurons must grow in such a way
that facilitates the current flow. We propose that power consumption is an
important factor by which neurons attain their final morphological appearance.Comment: 9 pages with 3 figures, submitted to Neuroscience Letter
Comparación entre las técnicas de cribado de patología cervical y las conizaciones de tres hospitales en españa
Objetivo: Analizar las características poblacionales y los métodos diagnósticos de patología cervical para la prevención del cáncer de cérvix de tres hospitales españoles para mejorar y unificar los programas de cribado y prevención. Material y métodos: Estudio retrospectivo de las características demográficas y clínicas de 408 mujeres con patología cervical uterina diagnosticadas en 3 hospitales españoles. Se comparan los factores de riesgo, el proceso diagnóstico y la indicación de tratamiento de dos grupos: las que requirieron conización cervical (n=222) y las que no precisaron tratamiento quirúrgico (n=186). También se analizan las recomendaciones vacunales y su grado de cumplimiento. Resultados: Las mujeres conizadas usaron más anticoncepción hormonal y tienen un mayor hábito tabáquico mientras que el número de compañeros sexuales es mayor en pacientes no conizadas. Más del 50% de pacientes con biopsia cervical positiva presentaron un resultado igual o más grave en la anatomía patológica de la pieza quirúrgica. Existen diferencias significativas en sensibilidad y valor predictivo positivo de la citología y de la determinación de HPV entre hospitales. La recomendación de vacunación en ambos grupos fue similar, el porcentaje de mujeres que no la cumplieron fue elevado y significativamente mayor entre pacientes conizadas. Conclusión: En nuestro medio las mujeres conizadas tienen características clínicas y epidemiológicas diferentes a las no conizadas, existen diferencias entre las técnicas diagnósticas de distintos hospitales y sin embargo la concordancia entre biopsia y resultado del cono es elevada. Sigue siendo necesaria una correcta educación sanitaria en relación con la vacunación en mujeres con patología cervical.
Background: To analyse the characteristics of the population and diagnostic methods related to the cervical cancer prevention program in three different-level hospitals of a Spanish region in order to improve and unify the screening program. Methods: We retrospectively studied demographic and clinical characteristics of 408 women with cervical lesions diagnosed in three hospitals in Aragon (Spain). Correlation between risk factors, diagnosis process and conisation indication was analysed divided in two groups: conisation required (n=222) or non-conisation (n=186). We also assessed the number of vaccine recommendations made to the patients and the degree of compliance. Results: Conisaited women more frequently used a combined hormonal contraceptive method and are more smokers, while the sexual partners are more in women without conisation. More than 50% of women con positive biopsy was confirmed after surgical treatment. There are significant differences between sensibility and positive predictive value of pap-smear and HPV determination in different hospitals. The recombinant vaccine was recommended to both groups at a similar rate. The percentage of women who were recommended to receive the vaccine but chose not to do it, was high in both groups but significantly higher in the Conisation group. Conclusion: In our environment conisaited women have different clinical and epidemiological profiles, there are differences between diagnosis techniques in different hospitals, however, the concordance between biopsy and definitive result is high. A good sanitary education is necessary in relation with the vaccination of women with cervical pathology
Enhancing neural-network performance via assortativity
The performance of attractor neural networks has been shown to depend
crucially on the heterogeneity of the underlying topology. We take this
analysis a step further by examining the effect of degree-degree correlations
-- or assortativity -- on neural-network behavior. We make use of a method
recently put forward for studying correlated networks and dynamics thereon,
both analytically and computationally, which is independent of how the topology
may have evolved. We show how the robustness to noise is greatly enhanced in
assortative (positively correlated) neural networks, especially if it is the
hub neurons that store the information.Comment: 9 pages, 7 figure
Update of the recommendations for the determination of biomarkers in colorectal carcinoma: National Consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology
In this update of the consensus of the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica SEOM) and the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica SEAP), advances in the analysis of biomarkers in advanced colorectal cancer (CRC) as well as susceptibility markers of hereditary CRC and molecular biomarkers of localized CRC are reviewed. Recently published information on the essential determination of KRAS, NRAS and BRAF mutations and the convenience of determining the amplifcation of human epidermal growth factor receptor 2 (HER2), the expression of proteins in the DNA repair pathway and the study of NTRK fusions are also evaluated. From the pathological point of view, the importance of analysing the tumour budding and poorly diferentiated clusters, and its prognostic value in CRC is reviewed, as well as the impact of molecular lymph node analysis on lymph node staging in CRC. The incorporation of pan-genomic technologies, such as next-generation sequencing (NGS) and liquid biopsy in the clinical management of patients with CRC is also outlined. All these aspects are developed in this guide, which, like the previous one, will remain open to any necessary revision in the future
Beyond Hebb: Exclusive-OR and Biological Learning
A learning algorithm for multilayer neural networks based on biologically
plausible mechanisms is studied. Motivated by findings in experimental
neurobiology, we consider synaptic averaging in the induction of plasticity
changes, which happen on a slower time scale than firing dynamics. This
mechanism is shown to enable learning of the exclusive-OR (XOR) problem without
the aid of error back-propagation, as well as to increase robustness of
learning in the presence of noise.Comment: 4 pages RevTeX, 2 figures PostScript, revised versio
Five microRNAs in Serum Are Able to Differentiate Breast Cancer Patients From Healthy Individuals
Breast cancer is the cancer with the most incidence and mortality in women. microRNAs
are emerging as novel prognosis/diagnostic tools. Our aim was to identify a serum
microRNA signature useful to predict cancer development. We focused on studying
the expression levels of 30 microRNAs in the serum of 96 breast cancer patients vs.
92 control individuals. Bioinformatic studies provide a microRNA signature, designated
as a predictor, based on the expression levels of five microRNAs. Then, we tested the
predictor in a group of 60 randomly chosen women. Lastly, a proteomic study unveiled
the overexpression and downregulation of proteins differently expressed in the serum of
breast cancer patients vs. that of control individuals. Twenty-six microRNAs differentiate
cancer tissue from healthy tissue, and 16 microRNAs differentiate the serum of cancer
patients from that of the control group. The tissue expression of miR-99a, miR-497,
miR-362, and miR-1274, and the serum levels of miR-141 correlated with patient survival.
Moreover, the predictor consisting of miR-125b, miR-29c, miR-16, miR-1260, and
miR-451 was able to differentiate breast cancer patients from controls. The predictor was
validated in 20 new cases of breast cancer patients and tested in 60 volunteer women,
assigning 11 out of 60 women to the cancer group. An association of low levels of miR-16
with a high content of CD44 protein in serum was found. Circulating microRNAs in serum
can represent biomarkers for cancer prediction. Their clinical relevance and the potential
use of the predictor here described are discussed
Polymorphisms in MDM2 and TP53 genes and risk of developing therapy-related myeloid neoplasms
One of the most severe complications after successful cancer therapy is the development of therapy-related myeloid neoplasms (t-MN). Constitutional genetic variation is likely to impact on t-MN risk. We aimed to evaluate if polymorphisms in the p53 pathway can be useful for predicting t-MN susceptibility. First, an association study revealed that the Pro variant of the TP53 Arg72Pro polymorphism and the G allele of the MDM2 SNP309 were associated with t-MN risk. The Arg variant of TP53 is more efficient at inducing apoptosis, whereas the Pro variant is a more potent inductor of cell cycle arrest and DNA repair. As regards MDM2 SNP309, the G allele is associated with attenuation of the p53 apoptotic response. Second, to evaluate the biological effect of the TP53 polymorphism, we established Jurkat isogenic cell lines expressing p53Arg or p53Pro. Jurkat p53Arg cells presented higher DNA damage and higher apoptotic potential than p53Pro cells, after treatment with chemotherapy agents. Only p53Pro cells presented t(15;17) translocation and del(5q). We suggest that failure to repair DNA lesions in p53Arg cells would lead them to apoptosis, whereas some p53Pro cells, prone to cell cycle arrest and DNA repair, could undergo misrepair, generating chromosomal abnormalities typical of t-MN
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