663 research outputs found
El Raonament probabilístic en alumnes d'educació infantil i de cicle mitjà d'educació primària
Es presenta un estudi realitzat amb
alumnes d'educació infantil i d'educació
primària per detectar els coneixements i
els raonaments previs que tenen sobre
probabilitat i atzar. A partir d'una activitat
senzilla, s'han analitzat els seus
raonaments probabilístics i s'ha fet una
comparativa entre els alumnes d'educació
infantil i els d'educació primària. Els
resultats no mostren diferències
significatives entre les dues poblacions de
l'estudi, ja que la majoria dels alumnes té
una òptica totalment determinista i no
entén l'atzar. Aquests resultats
coincideixen amb els d'altres autors com
Inhelder i Piaget (1955), que afirmen que
aquest raonament no s'obté fins a finals de
l'educació primària.This article presents a study of kindergarten
and primary school students designed to
detect pre-existing knowledge and reasoning
with respect to probability and chance. A
simple activity was used to analyse
probabilistic reasoning and a comparison
between kindergarten and primary school
students made. The results show no
significant differences between the two
groups, as most children do not understand
chance due to their completely deterministic
perspective. These results align with other
authors, such as Piaget and Inhelder (1951),
who argue that this type of reasoning is not
obtained until the end of
primary education
Validación proteómica de dianas genómicas en cáncer colorrectal
Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 18 de Julio de 200
Osteogenic effects of simvastatin-loaded mesoporous titania thin films
The use of statins in the field of bone regeneration is under current investigation due to the existing demand for non-toxic anabolic agents capable of enhancing bone formation in cases of substantial loss. Simvastatin, a coenzyme currently prescribed in clinics to inhibit cholesterol biosynthesis, has been proven to promote osteogenic differentiation by stimulating bone formation and inhibiting osteoclasts activity. We present the loading of simvastatin in mesoporous TiO2 thin films toward combining the pro-osteogenic properties of this molecule with the demonstrated bioactivity of titania. TiO2 thin films processing and characterization were carried out, as well as evaluation of MC3T3-E1 pre-osteoblasts viability when directly incubated with different concentrations of simvastatin, followed by the analysis of osteogenic activity promoted by simvastatin upon loading in the thin films. The accessible porosity of 36% quantified on the 95 ± 5 nm thick mesoporous thin films, together with pore diameters of 5.5 nm, necks between pores of 2.8 nm and interpore distances of 12 ± 2 nm allow the loading of the simvastatin molecule, as confirmed by FTIR spectroscopy. Simvastatin was found to promote MC3T3-E1 pre-osteoblasts viability at concentrations ≤0.01 g l−1, with a cytotoxicity threshold of 0.05 g l−1. We additionally found that film loadings with 0.001 g l−1 simvastatin promotes statistically higher MC3T3-E1 pre-osteoblast proliferation whereas a higher concentration of 0.01 g l−1 leads to statistically higher osteogenic activity (ALP synthesis), after 21 days of incubation, as compared to unloaded films. These results demonstrate the potential of simvastatin local administration based on bioactive mesoporous thin films to promote pro-osteogenic properties. By focusing this strategy on the coating of metallic prostheses, the supply of simvastatin to the target tissue can be favored and risks of systemic side effects will be reduced while enhancing the osteointegration of the implants.Fil: Lopez Alvarez, Miriam. Universidad de Vigo; EspañaFil: López Puente, Vanesa. Universidad de Vigo; EspañaFil: Rodriguez Valencia, Cosme. Universidad de Vigo; EspañaFil: Angelome, Paula Cecilia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liz Marzan, Luis M. Ikerbasque; EspañaFil: Serra, Julia. Universidad de Vigo; EspañaFil: Pastoriza Santos, Isabel. Universidad de Vigo; EspañaFil: Gonzalez, Pio. Universidad de Vigo; Españ
Surface phosphorylation of chitosan significantly improves osteoblast cell viability, attachment and proliferation
Chitosan biocompatibility is often associated with the structural similarities with glycosaminoglycans
(GAGs). Although all of the GAGs are built from repeating disaccharide units and some of them
contain N-glucosamine (the main hexosamine in the chitosan backbone), all of them also contain
negatively charged functional groups. These charged units are believed to have a crucial role for the
formation of proteoglycans and hence for key biochemical processes/signaling related to cell
functionality and survival. Lack of these groups in chitosan structure could be the reason for the
previously observed poor cell adhesion to this material. Herein, we report that plasma induced grafting
of negatively charged phosphonic groups can induce remarkably distinguishable cell response and
significantly improve the adhesion, proliferation and viability of osteoblast cells. The proposed plasma
induced polymerization is a very simple and versatile method and can be easily adapted to other
materials and different negatively charged units.The authors acknowledge funding from EU Marie Curie Actions, Alea Jacta Est (MEST-CT-2004-008104) and Portuguese Foundation for Science and Technology (FCT)(SFRH/BPD/34545/2007). This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Dissection of the inferior mesenteric vein versus of the inferior mesenteric artery for the genitourinary function after laparoscopic approach of rectal cancer surgery : a randomized controlled trial
Total Mesorectal Excision (TME) is the standard surgical technique for the treatment of rectal cancer. However, rates of sexual dysfunction ofup to 50% have been described after TME, and rates of urinary dysfunction of up to 30%. Although other factors are involved, the main cause of postoperative genitourinary dysfunction is intraoperative injury to the pelvic autonomic nerves. The risk is particularly high in the inferior mesenteric artery (IMA). The aim of this study is to compare pre- and post-TME sexual dysfunction, depending on the surgical approach usedin the inferior mesenteric vessels: either directly on the IMA, or from the inferior mesenteric vein (IMV) to the IMA. Prospective, randomized,controlled study of patients with rectal adenocarcinoma with neoadjuvant chemoradiotherapy, who will be randomly assigned to one of two groups depending on the surgical approach to the inferior mesenteric vessels. The main variable is pre- and postoperative sexual dysfunction; secondary variables are visualization and preservation of the pelvic autonomic nerves, pre- and postoperative urinary dysfunction, and pre- and postoperative quality of life. The sample will comprise 90 patients, 45 per group. The aim is to demonstrate that the dissection route from the IMV towards the IMA favors the preservation of the pelvic autonomic nerves and thus reducesrates of sexual dysfunction post-surgery. Ethical and Clinical Research Committee, Parc Taulí University Hospital: ID 017/315. ClinicalTrials.gov TAU-RECTALNERV-PRESERV-2018 (TRN: ) (Date of registration 04/03/2018)
Impact of prevalence ratios of chondroitin sulfate (CS)- 4 and -6 isomers derived from marine sources in cell proliferation and chondrogenic differentiation processes
[Abstract]
Osteoarthritis is the most prevalent rheumatic disease. During disease progression,
differences have been described in the prevalence of chondroitin sulfate (CS) isomers. Marine
derived-CS present a higher proportion of the 6S isomer, offering therapeutic potential.
Accordingly, we evaluated the effect of exogenous supplementation of CS, derived from the small
spotted catshark (Scyliorhinus canicula), blue shark (Prionace glauca), thornback skate (Raja clavata)
and bovine CS (reference), on the proliferation of osteochondral cell lines (MG-63 and T/C-28a2) and
the chondrogenic differentiation of mesenchymal stromal cells (MSCs). MG-G3 proliferation was
comparable between R. clavata (CS-6 intermediate ratio) and bovine CS (CS-4 enrichment), for
concentrations below 0.5 mg/mL, defined as a toxicity threshold. T/C-28a2 proliferation was
significantly improved by intermediate ratios of CS-6 and -4 isomers (S. canicula and R. clavata). A
dose-dependent response was observed for S. canicula (200 µg/mL vs 50 and 10 µg/mL) and bovine
CS (200 and 100 µg/mL vs 10 µg/mL). CS sulfation patterns discretely affected MSCs
chondrogenesis; even though S. canicula and R. clavata CS up-regulated chondrogenic markers
expression (aggrecan and collagen type II) these were not statistically significant. We demonstrate
that intermediate values of CS-4 and -6 isomers improve cell proliferation and offer potential for
chondrogenic promotion, although more studies are needed to elucidate its mechanism of action.Xunta de Galicia; IN607A 2017/11Xunta de Galicia; IN607B 2018/19European Commission; 0245_IBEROS_1_
Monitoring of miR-181a-5p and miR-155-5p Plasmatic Expression as Prognostic Biomarkers for Acute and Subclinical Rejection in de novo Adult Liver Transplant Recipients.
Background and Aims: News strategies for the accurate assessment of the state of immunosuppression (IS) in liver transplant recipients are needed to prevent rejection and minimize drug-related side effects. miRNAs can potentially be used as diagnostic or prognostic biomarkers in transplant patients. This study evaluated the capacity of a plasmatic miRNA panel (miR-155-5p, miR-122-5p, miR-181a-5p, and miR148-3p) as an early non-invasive prognostic and diagnostic biomarker for T cell-mediated acute rejection (TCMAR) and subclinical rejection (SCR) in adult liver recipients. Methods: A total of 145 liver recipients were included. All patients received a calcineurin inhibitor with or without mycophenolate mofetil and methylprednisolone. Plasmatic miRNA expression was assessed by qPCR before and at different time-points after liver transplantation. Results: Seventeen patients experienced TCMAR, and eight were diagnosed with SCR during the protocol biopsy at the 3rd month post-transplantation. Pre-transplantation, miR-155-5p expression was significantly higher in TCMAR patients and in SCR patients than in non-rejectors, and miR-181a-5p expression was also significantly higher in SCR patients than in non-rejectors. Post-transplantation, before transaminase-level modification, significantly increased miR-181a-5p, miR-155-5p, and miR-122-5p expression was observed in TCMAR and SCR patients. Binary logistic regression analyses showed, post-transplantation, that TCMAR risk was better predicted by individual expression of miR-181a-5p (LOGIT = -6.35 + 3.87*miR-181a-5p), and SCR risk was better predicted by the combination of miR-181a-5p and miR-155-5p expression (LOGIT = -5.18 + 2.27*miR-181a-5p+1.74*miR-155-5p). Conclusions: Pre-transplantation plasmatic miR-155-5p expression may be useful for stratifying low-immunologic-risk patients, and post-transplantation miR-181a-5p and miR-155-5p may be candidates for inclusion in early, non-invasive prognostic biomarker panels to prevent TCMAR or SCR and better identify patient candidates for IS minimization. Large prospective randomized multicenter trials are needed to refine the cut-off values and algorithms and validate the clinical usefulness of these biomarkers
Effects of High-Fat Diet and Maternal Binge-Like Alcohol Consumption and Their Influence on Cocaine Response in Female Mice Offspring
Backgroud: Prenatal alcohol exposure is a leading cause of neurobehavioral and neurocognitive deficits collectively known as fetal alcohol spectrum disorders (FASD), including eating disorders and increased risk for substance abuse as very common issues. In this context, the present study aimed to assess the interaction between alcohol exposure during gestation and lactation periods (PLAE) and a high fat diet (HFD) during childhood and adolescence. Methods: Pregnant C57BL/6 mice underwent a procedure for alcohol binge drinking during gestation and lactation periods. Subsequently, PLAE female offspring were fed with a HFD for 8 weeks and thereafter, nutrition-related parameters as well as their response to cocaine were assessed. Results: In our model, feeding young females with a HFD increased their triglyceride blood levels but did not induce an overweight compared to those fed with a standard diet. Moreover, PLAE affected how females responded to the fatty diet as they consumed less amount of food than water-exposed offspring, consistent with a lower gain of body weight. HFD increased the psychostimulant effects of cocaine. Surprisingly, PLAE reduced the locomotor responses to cocaine without modifying cocaine-induced reward. Moreover, PLAE prevented the striatal overexpression of cannabinoid 1 receptors induced by a HFD and induced an alteration of myelin damage biomarker in the prefrontal cortex, an effect that was mitigated by a HFD-based feeding. Conclusion: Therefore, in female offspring, some effects triggered by one of these factors, PLAE or a HFD, were blunted by the other, suggesting a close interaction between the involved mechanisms
Human breast adipose tissue: characterization of factors that change during tumor progression in human breast cancer
Adipose microenvironment is involved in signaling pathways that influence breast cancer. We aim to characterize factors that are modified: 1) in tumor and non tumor human breast epithelial cell lines when incubated with conditioned media (CMs) from human breast cancer adipose tissue explants (hATT) or normal breast adipose tissue explants (hATN); 2) in hATN-CMs vs hATT-CMs; 3) in the tumor associated adipocytes vs. non tumor associated adipocytes. We used hATN or hATT- CMs on tumor and non-tumor breast cancer cell lines. We evaluated changes in versican, CD44, ADAMTS1 and Adipo R1 expression on cell lines or in the different CMs. In addition we evaluated changes in the morphology and expression of these factors in slices of the different adipose tissues. The statistical significance between different experimental conditions was evaluated by one-way ANOVA. Tukey's post-hoc tests were performed within each individual treatment. hATT-CMs increase versican, CD44, ADAMTS1 and Adipo R1 expression in breast cancer epithelial cells. Furthermore, hATT-CMs present higher levels of versican expression compared to hATN-CMs. In addition, we observed a loss of effect in cellular migration when we pre-incubated hATT-CMs with chondroitinase ABC, which cleaves GAGs chains bound to the versican core protein, thus losing the ability to bind to CD44. Adipocytes associated with the invasive front are reduced in size compared to adipocytes that are farther away. Also, hATT adipocytes express significantly higher amounts of versican, CD44 and Adipo R1, and significantly lower amounts of adiponectin and perilipin, unlike hATN adipocytes.
We conclude that hATT secrete a different set of proteins compared to hATN. Furthermore, versican, a proteoglycan that is overexpressed in hATT-CMs compared to hATN-CMs, might be involved in the tumorogenic behavior observed in both cell lines employed. In addition, we may conclude that adipocytes from the tumor microenvironment show a less differentiated state than adipocytes from normal microenvironment. This would indicate a loss of normal functions in mature adipocytes (such as energy storage), in support of others that might favor tumor growth.Fil: Fletcher, Sabrina Johanna. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sacca, Paula Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Pistone Creydt, Mercedes. Instituto ; ArgentinaFil: Coló, Federico Andrés. Instituto ; ArgentinaFil: Serra, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Santiano, Flavia Eliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Sasso, Corina Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: López Fontana, Constanza Matilde. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Caron, Ruben Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Calvo, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Pistone Creydt, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin
CHL1 hypermethylation as a potential biomarker of poor prognosis in breast cancer
The CHL1 gene encodes a cell-adhesion molecule proposed as being a putative tumour-suppressor gene in breast cancer (BC). However, neither the underlying molecular mechanisms nor the clinical value of CHL1 downregulation in BC has been explored. The methylation status of three CpG sites in the CHL1 promoter was analysed by pyrosequencing in neoplastic biopsies from 142 patients with invasive BC and compared with that of non-neoplastic tissues. We found higher CHL1 methylation levels in breast tumours than in non-neoplastic tissues, either from mammoplasties or adjacent-to-tumour, which correlated with lower levels of protein expression in tumours measured by immunohistochemistry. A panel of five BC cell lines was treated with two epigenetic drugs, and restoration of CHL1 expression was observed, indicating in vitro dynamic epigenetic regulation. CHL1 was silenced by shRNA in immortalized but non-neoplastic mammary cells, and enhanced cell proliferation and migration, but not invasion, were found by real-time cell analysis. The prognostic value of CHL1 hypermethylation was assessed by the log-rank test and fitted in a Cox regression model. Importantly, CHL1 hypermethylation was very significantly associated with shorter progression-free survival in our BC patient series, independent of age and stage (p = 0.001). In conclusion, our results indicate that CHL1 is downregulated by hypermethylation and that this epigenetic alteration is an independent prognostic factor in BC
- …