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1.
Chaos ; 32(10): 103124, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36319283

RESUMEN

Previously, we observed that the student workload follows an inverse relation with the learning rate (an application of the kinematic notion of speed contextualized to the learning process). Motivated by this finding, we propose a quantitative estimation of the learning rate using a different source of information: the historical records of final grades of a given course. According to empirical data analyzed in other similar studies, the distribution functions of final grades exhibit a regular pattern: a Gaussian behavior for the approval region and a homogeneous distribution for the failed one. This fact is combined with the incidence of student elimination-desertion rules for introducing two simple agent-based models. Our analysis is complemented by revisiting the performance indicators typically employed to characterize the student promotion and progression. We discuss some other performance indicators to characterize the learning advancement of students: the group learning rate and the learning curve. We compare the results of Monte Carlo simulations with empirical data, observing a good agreement in the behavior of performance indicators derived from these sources. This analysis suggests an adaptive method for the readjustment of the student workload (the number of academic credits) considering the group learning rates during a follow-up period, which resembles the readjustment of prices of goods (and services) in correspondence with the evolution of supply and demand.


Asunto(s)
Aprendizaje , Carga de Trabajo , Humanos , Estudiantes , Modelos Estadísticos
2.
Chaos ; 32(10): 103130, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36319285

RESUMEN

We present a quantitative study of an online course developed during COVID19 sanitary emergency in Chile. We reconstruct the teaching-learning process considering the activity logs on digital platforms in order to answer the question of How do our students study? The results from the analysis evidence the complex adaptive character of the academic environment, which exhibits regularities similar to those found in financial markets (e.g., distributions of the daily time devoted to learning activities follow patterns like Pareto's or Zipf's law). Our empirical results illustrate (i) the relevance of economic notions in the understanding of the teaching-learning processes and (ii) the reliability of quantitative methods based on digital platforms to conduct experimental studies in this framework. We introduce in the present work a series of indicators to characterize the performance of professors, students' follow-up of the course, and their learning progress by crossing information with the results of assessments. In this context, the learning rate appears as a key statistical descriptor for the allocation of the student workload.


Asunto(s)
COVID-19 , Carga de Trabajo , Humanos , Reproducibilidad de los Resultados , Estudiantes , Aprendizaje
3.
Mol Psychiatry ; 21(10): 1434-40, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26598068

RESUMEN

Attention-deficit/hyperactivity disorder (ADHD) is a heritable, chronic, neurodevelopmental disorder with serious long-term repercussions. Despite being one of the most common cognitive disorders, the clinical diagnosis of ADHD is based on subjective assessments of perceived behaviors. Endophenotypes (neurobiological markers that cosegregate and are associated with an illness) are thought to provide a more powerful and objective framework for revealing the underlying neurobiology than syndromic psychiatric classification. Here, we present the results of applying genetic linkage and association analyses to neuropsychological endophenotypes using microsatellite and single nucleotide polymorphisms. We found several new genetic regions linked and/or associated with these endophenotypes, and others previously associated to ADHD, for example, loci harbored in the LPHN3, FGF1, POLR2A, CHRNA4 and ANKFY1 genes. These findings, when compared with those linked and/or associated to ADHD, suggest that these endophenotypes lie on shared pathways. The genetic information provided by this study offers a novel and complementary method of assessing the genetic causes underpinning the susceptibility to behavioral conditions and may offer new insights on the neurobiology of the disorder.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/genética , Endofenotipos/análisis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Trastornos del Conocimiento/genética , Colombia , Etnicidad/genética , Femenino , Estudios de Asociación Genética/métodos , Ligamiento Genético/genética , Predisposición Genética a la Enfermedad/genética , Predisposición Genética a la Enfermedad/psicología , Humanos , Masculino , Repeticiones de Microsatélite/genética , Persona de Mediana Edad , Pruebas Neuropsicológicas , Linaje , Polimorfismo de Nucleótido Simple/genética
4.
Antimicrob Agents Chemother ; 60(8): 4464-70, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27161639

RESUMEN

Immune response stimulation to prevent infection progression may be an adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC) is an immunomodulator involved in immune cell recruitment and activation. In this study, we aimed to evaluate the efficacy of LPC in combination with colistin, tigecycline, or imipenem in experimental murine models of peritoneal sepsis and pneumonia. We used Acinetobacter baumannii strain Ab9, which is susceptible to colistin, tigecycline, and imipenem, and multidrug-resistant strain Ab186, which is susceptible to colistin and resistant to tigecycline and imipenem. Pharmacokinetic and pharmacodynamic parameters for colistin, tigecycline, and imipenem and the 100% minimal lethal dose (MLD100) were determined for both strains. The therapeutic efficacies of LPC, colistin (60 mg/kg of body weight/day), tigecycline (10 mg/kg/day), and imipenem (180 mg/kg/day), alone or in combination, were assessed against Ab9 and Ab186 at the MLD100 in murine peritoneal sepsis and pneumonia models. The levels of pro- and anti-inflammatory cytokines, i.e., tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA) for the same experimental models after inoculating mice with the MLD of both strains. LPC in combination with colistin, tigecycline, or imipenem markedly enhanced the bacterial clearance of Ab9 and Ab186 from the spleen and lungs and reduced bacteremia and mouse mortality rates (P < 0.05) compared with those for colistin, tigecycline, and imipenem monotherapies. Moreover, at 4 h post-bacterial infection, Ab9 induced higher TNF-α and lower IL-10 levels than those with Ab186 (4 µg/ml versus 3 µg/ml [P < 0.05] and 2 µg/ml versus 3.4 µg/ml [P < 0.05], respectively). LPC treatment combined with colistin, tigecycline, or imipenem modestly reduced the severity of infection by A. baumannii strains with different resistance phenotypes compared to LPC monotherapy in both experimental models.


Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Lisofosfatidilcolinas/farmacología , Lisofosfatidilcolinas/uso terapéutico , Neumonía/tratamiento farmacológico , Sepsis/tratamiento farmacológico , Animales , Colistina/farmacología , Colistina/uso terapéutico , Ensayo de Inmunoadsorción Enzimática , Imipenem/farmacología , Imipenem/uso terapéutico , Interleucina-10/metabolismo , Ratones , Pruebas de Sensibilidad Microbiana , Minociclina/análogos & derivados , Minociclina/farmacología , Minociclina/uso terapéutico , Neumonía/microbiología , Sepsis/microbiología , Tigeciclina , Factor de Necrosis Tumoral alfa/metabolismo
5.
J Periodontal Res ; 50(6): 775-85, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25712760

RESUMEN

BACKGROUND AND OBJECTIVES: Probiotics create a biofilm and protect the oral tissues against the action of periodontal pathogenic bacteria. The aim of this study was to evaluate the effects of the oral probiotic Lactobacillus reuteri Prodentis upon the peri-implant health of edentulous patients with dental implants and peri-implant mucositis, establishing comparisons vs implants without peri-implant disease. MATERIAL AND METHODS: A double-blind, placebo-controlled, prospective cross-over study was made. The patients were all edentulous and were divided into two groups, (A) no peri-implant disease, and (B) peri-implant mucositis affecting one or more implants. Patients with peri-implantitis were excluded. The dosage was one tablet every 24 h over 30 d. All patients in both groups initially received the oral probiotic Lactobacillus reuteri Prodentis, followed by placebo. Patients started with probiotic treatment during 30 d, followed by a 6 mo washout period and the administration of placebo for the same period. The following parameters were studied: crevicular fluid volume, modified plaque index, probing depth, modified gingival index, and concentrations of interleukin 1ß, interleukin 6 and interleukin 8. RESULTS: A total of 77 implants were evaluated in 34 patients. Group A involved 22 patients with 54 implants without peri-implant alterations, and group B, 12 patients with mucositis affecting one or more implants (23 implants). After treatment with the probiotic, both the patients with mucositis and the patients without peri-implant disease showed improvements in the clinical parameters, with reductions in cytokine levels. In contrast, no such changes were observed with placebo. CONCLUSIONS: After treatment with the probiotic Lactobacillus reuteri in patients with implants presenting mucositis, the clinical parameters improved, and the cytokine levels decreased - in contraposition to the observations in the placebo group. Probiotic administration may be regarded as a good alternative for both the treatment of peri-implant mucositis and its prevention, as it also improved clinical parameters in the healthy individuals. Further studies involving larger patient series are needed regarding the effects of probiotics upon peri-implant health.


Asunto(s)
Implantación Dental/efectos adversos , Limosilactobacillus reuteri/fisiología , Mucositis/prevención & control , Probióticos/administración & dosificación , Comprimidos/administración & dosificación , Anciano , Estudios Cruzados , Citocinas/análisis , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mucositis/patología , Placebos/administración & dosificación , Estudios Prospectivos , Resultado del Tratamiento
6.
Artículo en Inglés, Español | MEDLINE | ID: mdl-38880356

RESUMEN

INTRODUCTION AND OBJECTIVE: Hip arthroplasty represents a significant advancement in the treatment of refractory chronic joint pain, improving quality of life and functionality. The objective of this study is to identify the risk factors associated with local and systemic complications in patients treated with total hip arthroplasty. METHODS: Observational, analytical, retrospective cohort study, which included 304 participants treated with total hip replacement. Comparison of variables between two groups was performed; 38 participants in the group with complications and 266 participants in the group without complications. RESULTS: The mean age in the complication group was 66 years (SD 18.7) and in the uncomplicated group it was 67,1 years (SD 15.1) (p 0,686). Female sex was observed in 73.3% of the group with complications and 65% in the group without complications. (p 0.292). Risk factors were: hip fracture as an indication for arthroplasty RR 1.33 [95% CI 1.004;1.775 p 0.047], coronary heart disease RR 1.31 [95% CI 1.067;1.616 p 0.010] and surgical bleeding equal to or greater than 400 cc RR 1.11 [95% CI 1.012;1.218 p 0.028]. CONCLUSIONS: The risk factors for complications in total hip arthroplasty were: hip fracture as the indication for arthroplasty, coronary artery disease, and surgical bleeding equal to or greater than 400 cc.

7.
Mol Psychiatry ; 17(7): 741-7, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21606926

RESUMEN

In previous studies of a genetic isolate, we identified significant linkage of attention deficit hyperactivity disorder (ADHD) to 4q, 5q, 8q, 11q and 17p. The existence of unique large size families linked to multiple regions, and the fact that these families came from an isolated population, we hypothesized that two-locus interaction contributions to ADHD were plausible. Several analytical models converged to show significant interaction between 4q and 11q (P<1 × 10(-8)) and 11q and 17p (P<1 × 10(-6)). As we have identified that common variants of the LPHN3 gene were responsible for the 4q linkage signal, we focused on 4q-11q interaction to determine that single-nucleotide polymorphisms (SNPs) harbored in the LPHN3 gene interact with SNPs spanning the 11q region that contains DRD2 and NCAM1 genes, to double the risk of developing ADHD. This interaction not only explains genetic effects much better than taking each of these loci effects by separated but also differences in brain metabolism as depicted by proton magnetic resonance spectroscopy data and pharmacogenetic response to stimulant medication. These findings not only add information about how high order genetic interactions might be implicated in conferring susceptibility to develop ADHD but also show that future studies of the effects of genetic interactions on ADHD clinical information will help to shape predictive models of individual outcome.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/genética , Cromosomas Humanos Par 11/genética , Ligamiento Genético/genética , Predisposición Genética a la Enfermedad/genética , Receptores Acoplados a Proteínas G/genética , Receptores de Péptidos/genética , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Encéfalo/metabolismo , Estudios de Casos y Controles , Colina/metabolismo , Glutamina/metabolismo , Humanos , Inositol/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Metilfenidato/uso terapéutico , Polimorfismo de Nucleótido Simple/genética , Protones
8.
Mol Psychiatry ; 15(11): 1053-66, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20157310

RESUMEN

Attention-Deficit/Hyperactivity Disorder (ADHD) has a very high heritability (0.8), suggesting that about 80% of phenotypic variance is due to genetic factors. We used the integration of statistical and functional approaches to discover a novel gene that contributes to ADHD. For our statistical approach, we started with a linkage study based on large multigenerational families in a population isolate, followed by fine mapping of targeted regions using a family-based design. Family- and population-based association studies in five samples from disparate regions of the world were used for replication. Brain imaging studies were performed to evaluate gene function. The linkage study discovered a genome region harbored in the Latrophilin 3 gene (LPHN3). In the world-wide samples (total n=6360, with 2627 ADHD cases and 2531 controls) statistical association of LPHN3 and ADHD was confirmed. Functional studies revealed that LPHN3 variants are expressed in key brain regions related to attention and activity, affect metabolism in neural circuits implicated in ADHD, and are associated with response to stimulant medication. Linkage and replicated association of ADHD with a novel non-candidate gene (LPHN3) provide new insights into the genetics, neurobiology, and treatment of ADHD.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/genética , Estimulantes del Sistema Nervioso Central/uso terapéutico , Predisposición Genética a la Enfermedad , Receptores Acoplados a Proteínas G/genética , Receptores de Péptidos/genética , Adolescente , Adulto , Encéfalo/metabolismo , Supervivencia Celular/genética , Niño , Preescolar , Mapeo Cromosómico , Femenino , Ligamiento Genético , Genotipo , Humanos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Polimorfismo Genético , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Péptidos/metabolismo
9.
Inflamm Res ; 60(7): 695-704, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21424515

RESUMEN

INTRODUCTION: Innate immune cells play a role in modulating host immune response. Part of the macrophage inflammatory response is the release of an array of inflammatory cytokines, important molecules during the development of innate and adaptative immunity. Several antioxidant agents have been used in the control of the inflammatory response. OBJECTIVE: To evaluate the anti-inflammatory effect of N-acetylcysteine (NAC) on the expression and secretion of inflammatory cytokines and interleukin (IL)-10 in lipopolysaccharide (LPS)-activated THP-1 macrophages under mild oxidative conditions. METHODS: Macrophages were activated by LPS (0.1 and 1 µg/ml) for up to 24 h. The effect of 15 mM NAC was evaluated at 2, 4, 6 and 24 h. mRNA expression of tumor necrosis factor (TNF)-α, IL-1ß, IL-6, IL-8 and IL-10 was assessed by real time PCR. The expression of the corresponding cytokines plus IL-12p70 was analyzed using a bead array for flow cytometry. RESULTS: NAC inhibits the inflammatory cytokines TNFα, IL-1ß and IL-6 in LPS-activated macrophages under mild oxidative conditions. IL-10 mRNA and protein expression are strongly downregulated in NAC-treated cells, which may further modify the inflammatory cytokine profile. CONCLUSION: NAC modulates immune functions during the inflammatory response.


Asunto(s)
Acetilcisteína/inmunología , Acetilcisteína/farmacología , Lipopolisacáridos/inmunología , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Animales , Línea Celular , Citocinas/inmunología , Humanos , Inmunidad Innata , Inflamación/inmunología , Macrófagos/citología , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo
10.
Br J Sports Med ; 45(10): 776-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19858111

RESUMEN

INTRODUCTION: Long-term Italian experience has provided evidence that preparticipation screening in competitive athletes with 12-lead ECG, history and physical examination is effective in identifying potentially lethal cardiovascular diseases. However, it is not being routinely practised in other countries. OBJECTIVES: To evaluate the usefulness of a preparticipation screening programme in a sample of players belonging to different disciplines. MATERIAL AND METHODS: From September 2006 to June 2008, 1220 young athletes from different sports disciplines underwent a cardiovascular examination that included personal and family history, physical examination and a resting 12-lead ECG. Those with abnormal findings were referred for additional tests. RESULTS: 1220 Athletes were screened: 96% males; mean age 23 (4) years. 90 (7.4%) players were referred for additional tests because of abnormal findings on baseline examination: 11 (0.9%) personal or family history, 4 (0.08%) physical examination and 75 (6.14%) 12-lead ECG. Echocardiographic assessment fulfilled left ventricular hypertrophy criteria in 8 of the 90 players. Of those, one case was considered an athlete's heart and one case was diagnosed with hypertrophic cardiomyopathy (septal thickness 23 mm). Further tests were needed in the remaining six, included in the "grey area", with one additional case of hypertrophic cardiomyopathy (apical variant) suggested by cardiac MRI. CONCLUSION: Given the ability of 12-lead ECG to detect individuals with structural heart disease, we suggest its inclusion as a part of preparticipation screening programmes.


Asunto(s)
Electrocardiografía/métodos , Cardiopatías/diagnóstico , Deportes , Adolescente , Adulto , Diagnóstico Precoz , Ecocardiografía , Salud de la Familia , Femenino , Humanos , Masculino , Anamnesis , Examen Físico , Derivación y Consulta , Adulto Joven
11.
J Vet Pharmacol Ther ; 34(5): 430-6, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21198677

RESUMEN

Canine aggression directed towards people is the most frequent reason for referral to behaviour practices. The serotonergic system and the hypothalamic-pituitary-adrenal (HPA) axis are believed to play an important role in controlling aggression. The selective serotonin reuptake inhibitor fluoxetine is the most commonly used drug in canine aggression. The aim of the present study was to assess the effect of a 30-day-long fluoxetine treatment on the peripheral serotonergic system and the HPA axis in canine aggression. To this end, the concentrations of serum serotonin (5-HT) and plasma cortisol and dehydroepiandrosterone (DHEA) were analysed in a group of aggressive (n = 22) and nonaggressive dogs (n = 9) during pre- (day 0) and posttreatment (day 30) conditions. Treatment caused a significant decrease in 5-HT concentrations (46% in the aggressive group and 32% in the control group). There was a trend towards a rise of DHEA/cortisol ratio values after treatment both in the aggressive and the control group. The determination of blood 5-HT and the DHEA/cortisol ratio could have important clinical applications in the future for deciding which animals might benefit from a given treatment as well as for monitoring the response. Further large-scale studies with this aim should be carried out to obtain sound conclusions.


Asunto(s)
Agresión/efectos de los fármacos , Conducta Animal/efectos de los fármacos , Perros , Fluoxetina/farmacología , Inhibidores Selectivos de la Recaptación de Serotonina/farmacología , Serotonina/sangre , Animales , Deshidroepiandrosterona/sangre , Femenino , Hidrocortisona/sangre , Masculino
12.
J Anim Physiol Anim Nutr (Berl) ; 94(3): 385-94, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19663981

RESUMEN

This experiment aimed at evaluating the effect of calf management and breed on the metabolic and luteal function of post-partum beef cows fed at maintenance. Fifty multiparous cows, 22 Parda de Montaña (PA) and 28 Pirenaica (PI), were assigned to either suckling once-daily for 30 min (RESTR) or ad libitum (ADLIB) from the day after calving. Blood samples were collected to analyse metabolites [non-esterified fatty acids (NEFA), beta-hydroxybutyrate, total protein and urea)], insulin-like growth factor-I (IGF-I) and progesterone (P4) at different intervals. Cows from RESTR maintained their live-weight (LW) over the first 3 months post-partum, whereas ADLIB cows lost nearly 4% LW. Both genotypes showed similar LW gains during this period (p > 0.10). Calf daily gains were lower in RESTR than in ADLIB treatment (p < 0.05), but similar across breeds (p > 0.10). Milk and lactose production were lower in RESTR cows than in ADLIB (p < 0.05). Milk and protein yield were greater in PA than in PI breed (p < 0.05). Serum NEFA, total protein and urea were higher in PI cows suckling ADLIB than in the rest (p < 0.05). Cows from PI breed had greater NEFA values than PA ones on the first week post-partum (p < 0.001). Circulating IGF-I was not affected by suckling frequency, breed nor their interaction (p > 0.10). Suckling frequency, but not breed, affected the interval from calving to first ovulation (p < 0.001), being shorter in RESTR than in ADLIB cows. In conclusion, the ad libitum suckling practice improved cow milk yield and offspring gain compared to once-daily suckling for 30 min from the day after calving, at the expense of impairing the onset of cyclicity. The effect of calf management was confounded with breed on the studied blood biochemical constituents, but any of these metabolites influenced the role of endocrine IGF-I in these genotypes.


Asunto(s)
Crianza de Animales Domésticos , Bovinos/genética , Bovinos/metabolismo , Cuerpo Lúteo/fisiología , Parto/fisiología , Ácido 3-Hidroxibutírico/análisis , Animales , Animales Lactantes , Ácidos Grasos no Esterificados/análisis , Femenino , Lactancia , Leche/química , Proteínas de la Leche/análisis , Embarazo , Estaciones del Año , España , Factores de Tiempo , Urea/análisis
13.
J Anim Physiol Anim Nutr (Berl) ; 94(6): e241-50, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20050944

RESUMEN

The episodic release of luteinizing hormone (LH) and growth hormones (GH) was studied in three suckling regimens and two breeds of Spanish suckled cows. Parda de Montaña (PA) cows (n = 21) were assigned to once-daily, twice-daily or ad libitum (ADLIB) suckling. Pirenaica (PI) cows (n = 7) were used to evaluate the breed effect in twice-daily suckling. Coccygeal blood samples were collected twice weekly during lactation to determine the interval from calving to first ovulation through peripheral progesterone. On day 32 ± 3 post-partum, jugular blood samples were drawn at 15 min intervals during 8 h to analyse circulating LH and GH. The interval to first ovulation was greater in PA cows suckling ADLIB than in restricted suckling treatment (RESTR1), whereas in RESTR2 it did not differ from the other two treatments. There were no differences between PA and PI cows in the interval to first ovulation. RESTR1 cows showed a tendency to have shorter LH peak widths than ADLIB cows. PA cows showed a tendency to have longer LH peak widths than their PI counterparts. There were no differences across treatments or breeds in any of the GH measures of secretion. The LH release was more affected by breed than by suckling frequency, whereas that of GH was not influenced by any of these parameters. The variables that best allowed discrimination between ADLIB and restricted nursing systems were the interval to post-partum first ovulation, LH peak number and the mean GH concentration.


Asunto(s)
Bovinos/sangre , Bovinos/fisiología , Hormona del Crecimiento/sangre , Lactancia/fisiología , Hormona Luteinizante/sangre , Animales , Animales Lactantes , Bovinos/genética , Femenino , Lactancia/sangre , España , Factores de Tiempo
14.
Mater Sci Eng C Mater Biol Appl ; 114: 111013, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32993985

RESUMEN

Ceramic materials such as calcium phosphates (CaPs) with a composition similar to the mineral phase of bones and polymeric polylactic acid (PLA) are potential candidates for the manufacturing of scaffolds to act as bone substitutes and for tissue engineering applications, due to their bioresorbability and biocompatibility. Variables such as porosity, topography, morphology, and mechanical properties play an essential role in the scaffolds response. In this paper, a polymer/ceramic composite filament of 1.7 mm in diameter based on PLA and biphasic calcium phosphates (BCPs) was obtained by hot-melt extrusion in a single screw extruder. The particles of BCP were obtained by solution-combustion synthesis, and the PLA used was commercial grade. The BCPs ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopy (TEM), and Brunauer, Emmett, and Teller (BET). It was possible to confirm that the main inorganic phases were hydroxyapatite (HAP) and tricalcium phosphate (TCP) with grain sizes below 100 nm and with high porosity. The Filaments obtained are a bit fragile but were able to be used in fused deposition modelling (FDM) using low-cost commercial printers. The filaments were characterized by SEM and energy dispersive X-ray (EDX). The in-vitro tests of filaments showed deposition of apatite phases on their surface, non-cytotoxic behavior, adequate cell proliferation and cell adhesion.


Asunto(s)
Fosfatos de Calcio , Hidroxiapatitas , Cerámica , Durapatita , Ensayo de Materiales , Poliésteres , Porosidad , Ingeniería de Tejidos , Andamios del Tejido
15.
Sci Rep ; 10(1): 8525, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32444614

RESUMEN

For several years, reports have been published about fluctuations in measured radioactive decay time-series and in some instances linked to astrophysical as well as classical environmental influences. Anomalous behaviors of radioactive decay measurement and measurement of capacitance inside and outside a modified Faraday cage were documented by our group in previous work. In the present report, we present an in-depth analysis of our measurement with regard to possible correlations with space weather, i.e. the geomagnetic activity (GMA) and cosmic-ray activity (CRA). Our analysis revealed that the decay and capacitance time-series are statistically significantly correlated with GMA and CRA when specific conditions are met. The conditions are explained in detail and an outlook is given on how to further investigate this important finding. Our discovery is relevant for all researchers investigating radioactive decay measurements since they point out that the space weather condition during the measurement is relevant for partially explaining the observed variability.

16.
J Small Anim Pract ; 50(2): 87-91, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19200264

RESUMEN

OBJECTIVES: The aim of this study was to describe the prevalence and severity of behavioural changes associated with age and their relationship to risk factors such as sex, reproductive status, bodyweight and age. METHODS: A cross-sectional study design was chosen. A total of 325 geriatric dogs were included. Owners of dogs older than nine years were interviewed by a veterinary behaviourist. Structured phone interviews were used to gather information about four behavioural categories related to cognitive impairment: sleep/wake cycles, social interaction, learning and house training and signs of disorientation. RESULTS: Signs of cognitive impairment showed a prevalence of 22.5 per cent in geriatric dogs. Sex and age emerged as significant predictor variables. Females and neutered dogs were significantly more affected than males and entire dogs, respectively. Prevalence and severity increased with age. Although weight was not a statistically significant predictor variable, smaller animals had greater odds of showing age-related cognitive impairment. The most impaired behavioural categories were social interaction and house training. CLINICAL SIGNIFICANCE: Age-related behavioural changes should be considered by practicing veterinarians because of their relative high prevalence among geriatric dogs, especially in females.


Asunto(s)
Envejecimiento/psicología , Conducta Animal , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/psicología , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/psicología , Animales , Castración , Estudios Transversales , Perros , Femenino , Humanos , Entrevistas como Asunto , Modelos Logísticos , Masculino , Prevalencia , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores Sexuales
17.
Restor Neurol Neurosci ; 26(6): 459-65, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19096133

RESUMEN

PURPOSE: Amyotrophic Lateral Sclerosis (ALS) is a paralyzing disorder that kills individuals within three to five years of onset without any possibility for effective treatment. One proposed therapy has been the use of neurotrophic factors to inhibit the apoptosis of motorneurones. At the present, one way to deliver neurotrophic factors after intramuscular injection to the motor neurones is through the use of adenoviral vectors. An alternative strategy is the use of the atoxic C fragment of tetanus toxin (TTC) as a neurotrophic factor carrier for motorneurones. METHODS: We have produced the recombinant protein fusion Glial Derived Neurotrophic Factor and C fragment of tetanus toxin (GDNF-TTC) and we have tested its antiapoptotic activity in degeneration culture cells and in the symptomatic SOD;{G93A} transgenic animal model for ALS. RESULTS: We demonstrated that GDNF-TTC induces the neuronal survival Akt kinase pathway in mouse cortical culture neurons and~maintains its antiapoptotic neuronal activity in Neuro2A cells. Moreover, we have found that genetic fusion is able to increase survival by 9 days and improves life quality in symptomatic ALS animal models. CONCLUSION: These results suggest that recombinant GDNF-TTC fusion protein intramuscular injections provide a potential therapy for ALS treatment.


Asunto(s)
Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Esclerosis Amiotrófica Lateral/microbiología , Factor Neurotrófico Derivado de la Línea Celular Glial/uso terapéutico , Fragmentos de Péptidos/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Toxina Tetánica/uso terapéutico , Esclerosis Amiotrófica Lateral/genética , Análisis de Varianza , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Células Cultivadas , Corteza Cerebral/citología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Técnicas de Transferencia de Gen , Humanos , Ratones , Ratones Transgénicos , Neuroblastoma , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Proteína Oncogénica v-akt/metabolismo , Superóxido Dismutasa/genética , Análisis de Supervivencia , Transfección
18.
Oncogene ; 25(8): 1174-85, 2006 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-16247457

RESUMEN

The PI3K/PTEN/Akt signaling pathway has emerged in recent years as a main player in human cancers, increasing proliferation and decreasing apoptosis of transformed cells, and thus becoming a potential target for therapeutic intervention. Our previous data have demonstrated that Akt-mediated signaling is of a key relevance in the mouse skin carcinogenesis system, one of the best-known models of experimental carcinogenesis. Here, we investigated the involvement of several pathways as mediators of Akt-induced increased proliferation and tumorigenesis in keratinocytes. Tumors produced by subcutaneous injection of Akt-transformed keratinocytes showed increased Foxo3a phosphorylation, but no major alterations in p21(Cip1/WAF1), p27(Kip1) or mdm2 expression and/or localization. In contrast, we found increased expression and nuclear localization of DeltaNp63, beta-catenin and Lef1. Concomitantly, we also found increased expression of c-myc and CycD1, targets of the beta-catenin/Tcf pathway. Such increase is associated with increased phosphorylation and stabilization of c-myc protein as well as increased translation of c-myc and CycD1 due to mTOR activation. Using immunohistochemistry approaches in samples of oral dysplasias and human head and neck squamous cell carcinomas, we confirmed that increased Akt activation significantly correlates with increased DeltaNp63 and CycD expression, c-myc phosphorylation and nuclear accumulation of beta-catenin. Collectively, these results demonstrate that Akt is able to transform keratinocytes by specific mechanisms involving transcriptional and post-transcriptional processes.


Asunto(s)
Transformación Celular Neoplásica , Queratinocitos/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Cutáneas/metabolismo , Animales , Proliferación Celular , Células Cultivadas , Ciclina D1/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/metabolismo , Inyecciones Subcutáneas , Queratinocitos/patología , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Desnudos , Fosfoproteínas/metabolismo , Fosforilación , Proteínas Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR , Transactivadores/metabolismo , beta Catenina/metabolismo
19.
J Reprod Immunol ; 75(1): 1-10, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17343919

RESUMEN

An appropriate local environment is necessary for successful implantation. Oxidative stress is implicated in the pathogenesis of several pathologies, and may contribute to early pregnancy failure. Antioxidant therapies have been studied in infertility. In this study, we have assessed the antioxidant activity of N-acetylcysteine (NAC), flavonoids (quercetin, catechin) and alpha-tocopherol in an oxidative model of endometrial cells (RL95). Endometrial cells were incubated at several hydrogen peroxide concentrations. Antioxidant effects of NAC (15 mM), quercetin (150 microM), catechin (150 microM) and alpha-tocopherol included in liposomes (1.6 microg) were assessed by measuring cell viability by the MTT assay. Alpha-tocopherol-liposomes taken up by endometrial cells were assessed by HPLC. All liposomes used were able to introduce alpha-tocopherol into cells. The antioxidant effect of NAC and quercetin improved the viability of oxidised cells, and this effect was observed when the oxidant and antioxidant were coincubated. No viability change occurred when the antioxidant was added before or after the oxidant. The antioxidant effect of NAC was better than that of quercetin. When catechin or alpha-tocopherol were used in the same conditions, no antioxidant effect was detected in cells in culture. These results demonstrate that NAC and quercetin are good H2O2 scavengers.


Asunto(s)
Acetilcisteína/farmacología , Antioxidantes/farmacología , Endometrio/citología , Endometrio/metabolismo , Flavonoides/farmacología , alfa-Tocoferol/farmacología , Acetilcisteína/metabolismo , Antioxidantes/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Neoplasias Endometriales/metabolismo , Endometrio/efectos de los fármacos , Femenino , Flavonoides/metabolismo , Humanos , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/toxicidad , Liposomas , Oxidantes/metabolismo , Estrés Oxidativo/efectos de los fármacos , alfa-Tocoferol/metabolismo
20.
Clin Transl Oncol ; 19(6): 682-694, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28074400

RESUMEN

The relationship between obesity and cancer is clear and is present at all times during course of the disease. The importance of obesity in increasing the risk of developing cancer is well known, and some of the most prevalent tumours (breast, colorectal, and prostate) are directly related to this risk increase. However, there is less information available on the role that obesity plays when the patient has already been diagnosed with cancer. Certain data demonstrate that in some types of cancer, obese patients tolerate the treatments more poorly. Obesity is also known to have an impact on the prognosis, favouring lower survival rates or the appearance of secondary tumours. In this consensus statement, we will analyse the scientific evidence on the role that obesity plays in patients already diagnosed with cancer, and the available data on how obesity control can improve the quality of daily life for the cancer patient.


Asunto(s)
Neoplasias/complicaciones , Neoplasias/epidemiología , Obesidad/complicaciones , Obesidad/epidemiología , Guías como Asunto , Humanos , España/epidemiología
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