262 research outputs found

    On the origin of the selectivity of plasmidic H-NS towards horizontally acquired DNA: Linking H-NS oligomerization and cooperative DNA binding

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    The nucleoid-associated protein H-NS is a global modulator of the expression of genes associated with adaptation to environmental changes. A variant of H-NS expressed in the R27 plasmid was previously shown to selectively modulate the expression of horizontally acquired genes, with minimal effects on core genes that are repressed by the chromosomal form of H-NS. Both H-NS proteins are formed by an oligomerization domain and a DNA-binding domain, which are connected by a linker that is highly flexible in the absence of DNA. We studied DNA binding by means of oligomer-forming chimeric proteins in which domains of the chromosomal and plasmidic variants are exchanged, as well as in monomeric truncated forms containing the DNA-binding domain and variable portions of the linker. Point mutations in the linker were also examined in full-length and truncated H-NS constructs. These experiments show that the linker region contributes to DNA binding affinity and that it is a main component of the distinct DNA binding properties of chromosomal and plasmidic H-NS. We propose that interactions between the linker and DNA limit the flexibility of the connection between H- NS oligomerization and DNA binding and provide an allosteric indirect readout mechanism to detect long- range distortions of DNA, thus enabling discrimination between core and horizontally acquired DNA

    CONSULTORÍA CIENTÍFICO-TÉCNICA PARA DETERMINAR LA LÍNEA BASE Y MEJORA DE SST EN DIANA IMILLA ALARCÓN MEDINA

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    Siguiendo la metodología de consultoría de Milan Kubr, la cual está basada en 5 fases principales, las cuales son la iniciación de la tarea o preparativo, el diagnóstico, la planificación de la acción, la aplicación y por último la terminación (Kubr, 1997). Se planteó la iniciativa de una mejora de condiciones laborales para los trabajadores la cual fue la propuesta realizada para la empresa Diana Imilla Alarcón/Style Bonet, bajo la normatividad y estándares vigentes en la Seguridad y Salud en el Trabajo teniendo como referente, la propuesta para la mejora en la implementación de los estándares mínimos  del SG SST en la empresa servicios MyM, para el segundo semestre del 2019 y principios del 2020 (Moreno, Gómez, Pérez, Escobar, Acevedo, 2019). Dicha propuesta tuvo como objetivo la mejora del Sistema de Seguridad y Salud en el Trabajo basado en el análisis de los resultados como base de una descripción aplicada según la naturaleza y el cumplimiento que permitiera la mejora de condiciones de los empleados bajo este aspecto. Esta mejora se especifica para los 8 empleados que tiene la empresa Diana Alarcón / Style Bonet, bajo las técnicas de observación y recopilación de información mediante la recolección de datos (Gallardo, Y., Moreno, A., 1999). La técnica utilizada para esta recolección de datos fue un método sencillo de encuestas realizadas a los trabajadores de la empresa, la cual se puede tener resultados visuales para su análisis y el uso en pro de la investigación. Como técnica de análisis se realizó la revisión constante de los diagnósticos, las encuestas y las observaciones realizadas, lo cual ayudó a tener una realidad de las condiciones de Seguridad y Salud en el trabajo que se tienen en la empresa. Basados en esto, se pudo realizar la propuesta de mejora de las condiciones laborales y el posterior cumplimiento de la legislación pertinente aplicada por parte de la empresa Diana Imilla Alarcón /Style Bonet. Los resultados obtenidos nos muestran que la empresa por sus características tiene un nivel de riesgo III, lo cual debe cumplir 7 estándares mínimos de calidad, de los cuales en este momento solamente cumple con el 14% total que debe tener). La consultoría científica ayudo a identificar oportunidades de mejora para cumplir con el 86% restante de los estándares mínimos que se deben cumplir (Ministerio del trabajo, 2019)

    Alzheimer´s Disease-associated Aβ42 Peptide: Expression and Purification for NMR Structural Studies

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    Background: The aggregation of the amyloid-beta peptide (Aβ) in the brain is strongly associated with Alzheimer´s disease (AD). However, the heterogeneous and transient nature of this process has prevented identification of the exact molecular form of Aβ responsible for the neurotoxicity observed in this disease. Therefore, characterizing Aβ aggregation is of utmost importance in the field of AD. Nuclear magnetic resonance spectroscopy (NMR) is a technique that holds great potential to achieve this goal. However, it requires the use of specific labels introduced through recombinant expression of Aβ. Objective: In this paper, we report on a straightforward expression and purification protocol to obtain [U-15N] and [U-2H,13C,15N] Aβ42. Method: Aβ42 is expressed fused to Small Ubiquitin-like Modifier (SUMO) protein, which prevents Aβ42 aggregation. Results: The solubilizing capacity of SUMO has allowed us to design a purification protocol involving immobilized metal affinity chromatography (IMAC), a desalting step, and two size exclusion chromatography (SEC) purifications. Conclusion: This approach, which does not require the use of costly and time-consuming reversed phase high performance liquid chromatography (RP-HPLC), offers a much straightforward strategy to those previously described to obtain [U-15N] Aβ42 and it is the first protocol through which to achieve [U-2H,13C,15N] Aβ42. The peptides obtained are of high purity and have the required isotope enrichment to support NMR-based structural studies

    Mitigación y adaptación al Cambio Climático del sector turístico

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    La Agencia Estatal de Meteorología (AEMET) define clima como la descripción estadística del tiempo atmosférico en términos de valores medios y de la variabilidad de las magnitudes correspondientes - temperatura, precipitación o viento entre otras – durante períodos dilatados de tiempo, es por lo tanto el estado promedio de situaciones del tiempo atmosférico en un lugar determinado. A nivel planetario, Según la Organización Meteorológica Mundial (OMM) el período habitualde promedio es de 30 años el clima es un sistema, una entidad compuesta por elementos relacionados entre sí y que son a su vez sistemas terrestres: atmósfera, hidrosfera, criosfera, litosfera, edafosfera y biosfera. En consecuencia, es un aparato complejo, pues las variaciones que tienen lugar en cada uno de sus componentes conlleva su modificación a través de la actuación de diversos factores.2019-2

    Fatigue, emotional distress, and illness uncertainty in patients with metastatic cancer: results from the prospective NEOETIC_SEOM study

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    A cancer diagnosis can have a substantial impact on a patient's mental health and quality of life. The aim of this study was to investigate the prevalence of fatigue, emotional distress, and uncertainty and examine the predictive value they have on the quality of life of advanced cancer patients. A prospective, multicenter study was conducted between February 2020 and May 2021 of individuals diagnosed with an advanced, unresectable neoplasm prior to initiating systemic antineoplastic treatment. Participants completed questionnaires to quantify fatigue, emotional distress, disease uncertainty, and quality of life. A linear regression analysis was performed to study the predictive QoL variables. The study population comprised 508 patients, 53.7% of whom were male and had a mean age of 54.9 years. The most common cancers were digestive (40.6%), bronchopulmonary (29.1%), and breast (8.5%); the most frequent histology was adenocarcinoma (63%); and most were stage IV (79.7%). More than half (55.7%) suffered fatigue, and 47.7% exhibited emotional distress; both were more prevalent among women. Fatigue, emotional distress, and disease uncertainty all correlate with diminished quality of life. Similarly, ECOG performance status and the demographic variables of age, sex, and comorbidities impacted quality of life. This patient sample displayed a high prevalence of fatigue and emotional distress, together with illness uncertainty, which are clearly linked to waning quality of life. To decrease the experience of fatigue and improve mental health treatment in cancer patients, interventions based on a biopsychosocial model must be intensified

    Activity of ulilysin, an archaeal PAPP-A-related gelatinase and IGFBP protease

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    Human growth and development are conditioned by insulin-like growth factors (IGFs), which have also implications in pathology. Most IGF molecules are sequestered by IGF-binding proteins (IGFBPs) so that exertion of IGF activity requires disturbance of these complexes. This is achieved by proteolysis mediated by IGFBP proteases, among which the best characterised is human PAPP-A, the first member of the pappalysin family of metzincins. We have previously identified and studied the only archaeal homologue found to date, Methanosarcina acetivorans ulilysin. This is a proteolytically functional enzyme encompassing a pappalysin catalytic domain and a pro-domain involved in maintenance of latency of the zymogen, proulilysin. Once activated, the protein hydrolyses IGFBP-2 to -6 and insulin chain β in vitro. We report here that ulilysin is also active against several other substrates, viz (azo)casein, azoalbumin, and extracellular matrix components. Ulilysin has gelatinolytic but not collagenolytic activity. Moreover, the proteolysis-resistant skeletal proteins actin and elastin are also cleaved, as is fibrinogen, but not plasmin and α1-antitrypsin from the blood coagulation cascade. Ulilysin develops optimal activity at pH 7.5 and strictly requires peptide bonds preceding an arginine residue, as determined by means of a novel fluorescence resonance energy transfer assay, thus pointing to biotechnological applications as an enzyme complementary to trypsi

    Can Oncologists Prompt Patient Prognostic Awareness to Enhance Decision-Making? Data From the NEOetic Study

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    Introduction: Anti-neoplastic therapy improves the prognosis for advanced cancer, albeit it is not curative. An ethical dilemma that often arises during patients’ first appointment with the oncologist is to give them only the prognostic information they can tolerate, even at the cost of compromising preference-based decision-making, versus giving them full information to force prompt prognostic awareness, at the risk of causing psychological harm. Methods: We recruited 550 participants with advanced cancer. After the appointment, patients and clinicians completed several questionnaires about preferences, expectations, prognostic awareness, hope, psychological symptoms, and other treatment-related aspects. The aim was to characterize the prevalence, explanatory factors, and consequences of inaccurate prognostic awareness and interest in therapy. Results: Inaccurate prognostic awareness affected 74%, conditioned by the administration of vague information without alluding to death (odds ratio [OR] 2.54; 95% CI, 1.47-4.37, adjusted P = .006). A full 68% agreed to low-efficacy therapies. Ethical and psychological factors oriented firstline decision-making, in a trade-off in which some lose quality of life and mood, for others to gain autonomy. Imprecise prognostic awareness was associated with greater interest in low-efficacy treatments (OR 2.27; 95% CI, 1.31-3.84; adjusted P = .017), whereas realistic understanding increased anxiety (OR 1.63; 95% CI, 1.01-2.65; adjusted P = 0.038), depression (OR 1.96; 95% CI, 1.23-3.11; adjusted P = .020), and diminished quality of life (OR 0.47; 95% CI, 0.29-0.75; adjusted P = .011). Conclusion: In the age of immunotherapy and targeted therapies, many appear not to understand that antineoplastic therapy is not curative. Within the mix of inputs that comprise inaccurate prognostic awareness, many psychosocial factors are as relevant as the physicians’ disclosure of information. Thus, the desire for better decision-making can actually harm the patient

    Psychological factors and prognostic communication preferences in advanced cancer: multicentre study

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    Objectives: Communication regarding prognosis to patients with advanced cancer is fundamental for informed medical decision making. Our objective was to analyse (1) the proportion of subjects with advanced cancer who prefer to know their prognosis, (2) the characteristics associated with patients’ preference for prognostic information, (3) the psychological factors that impact the preference to know prognosis and 4) the concordance between preference for prognostic information perceived among physicians and patients. Methods: A prospective, cross-sectional design was adopted. Data were collected from 748 participants with advanced cancer at 15 tertiary hospitals in Spain. Participants completed the following questionnaires: Mental Adjustment to Cancer; Trust in the Physician; Uncertainty in Illness Scale Patient’s Prognostic Preferences. Results: Fifty-two per cent of advanced cancer sufferers preferred to know the prognosis of their disease. Compared with participants who preferred not to know, those who did reported more uncertainty, greater satisfaction with their physician and higher scores on positive attitude (all p=0.001). Thirty-seven per cent of the physicians believed that patients want to know their prognosis, indicating that they underestimate the number of such patients. No significant differences were found regarding preference to know prognosis as a function of sociodemographic and clinical variables. Conclusions: A substantial proportion of individuals with advanced cancer prefer to know the prognosis of their disease. It appears that knowing their prognosis was mainly motivated by a need to maintain a positive attitude, lessen uncertainty and by satisfaction with the physician. It is important to explore patients’ preferences for information to offer more personalised communication

    Early dysfunction of functional connectivity in healthy elderly with subjective memory complaints

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    It is still an open question whether subjective memory complaints (SMC) can actually be considered to be clinically relevant predictors for the development of an objective memory impairment and even dementia. There is growing evidence that suggests that SMC are associated with an increased risk of dementia and with the presence of biological correlates of early Alzheimer's disease. In this paper, in order to shed some light on this issue, we try to discern whether subjects with SMC showed a different profile of functional connectivity compared with subjects with mild cognitive impairment (MCI) and healthy elderly subjects. In the present study, we compare the degree of synchronization of brain signals recorded with magnetoencephalography between three groups of subjects (56 in total): 19 with MCI, 12 with SMC and 25 healthy controls during a memory task. Synchronization likelihood, an index based on the theory of nonlinear dynamical systems, was used to measure functional connectivity. Briefly, results show that subjects with SMC have a very similar pattern of connectivity to control group, but on average, they present a lower synchronization value. These results could indicate that SMC are representing an initial stage with a hypo-synchronization (in comparison with the control group) where the brain system is still not compensating for the failing memory networks, but behaving as controls when compared with the MCI subjects

    A comprehensive custom panel design for routine hereditary cancer testing: preserving control, improving diagnostics and revealing a complex variation landscape

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    We wanted to implement an NGS strategy to globally analyze hereditary cancer with diagnostic quality while retaining the same degree of understanding and control we had in pre-NGS strategies. To do this, we developed the I2HCP panel, a custom bait library covering 122 hereditary cancer genes. We improved bait design, tested different NGS platforms and created a clinically driven custom data analysis pipeline. The I2HCP panel was developed using a training set of hereditary colorectal cancer, hereditary breast and ovarian cancer and neurofibromatosis patients and reached an accuracy, analytical sensitivity and specificity greater than 99%, which was maintained in a validation set. I2HCP changed our diagnostic approach, involving clinicians and a genetic diagnostics team from panel design to reporting. The new strategy improved diagnostic sensitivity, solved uncertain clinical diagnoses and identified mutations in new genes. We assessed the genetic variation in the complete set of hereditary cancer genes, revealing a complex variation landscape that coexists with the disease-causing mutation. We developed, validated and implemented a custom NGS-based strategy for hereditary cancer diagnostics that improved our previous workflows. Additionally, the existence of a rich genetic variation in hereditary cancer genes favors the use of this panel to investigate their role in cancer risk
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