The DNA-methyltransferase inhibitors zebularine and decitabine induce mitochondria-mediated apoptosis and DNA damage in p53 mutant leukemic T cells

DNA methyltransferase (DNMT)-inhibiting nucleoside analogs reactivate the expression of tumor suppressor genes and apoptosis-related genes silenced by methylation, thus favoring the induction of apoptosis in tumor cells. Moreover, induction of DNA damage seems to contribute to their antitumor effect. However, the apoptotic signaling pathway induced by these demethylating drugs is not well understood. Here, we have investigated the induction of apoptosis by two nucleoside DNMT inhibitors, decitabine and zebularine, in leukemic T cells. Both inhibitors induced caspase-dependent apoptosis in Jurkat, CEM-6 and MOLT-4 leukemia T cell lines, all with mutant p53, whereas resting and activated normal T lymphocytes were highly resistant to these demethylating agents. Although decitabine and zebularine showed different ability to induce apoptosis and cell cycle arrest among the three cell lines, they similarly activated the intrinsic apoptotic pathway by inducing mitochondrial alterations such as Bak activation, loss of transmembrane potential and generation of reactive oxygen species (ROS). Accordingly, Bcl-2- and Bcl-xL-overexpressing Jurkat cells, as well as caspase-9-deficient Jurkat cells, were resistant to apoptosis induced by decitabine and zebularine. Interestingly, ROS production seemed to be necessary for the induction of apoptosis. Apoptotic events, such as Bak and caspase activation, started as soon as 20 hr after treatment with either decitabine or zebularine. In addition, progression of apoptosis triggered by both DNMT inhibitors was paralleled by the induction of DNA damage. Our results suggest that the mitochondrial apoptotic pathway activated by decitabine and zebularine in p53 mutant leukemic T cells depends mainly on the induction of DNA damage.Fondo de Investigación Sanitaria, Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo; Grant number: PI06071

DOT-WINGED CRAKE PORZANA SPILOPTERA (RALLIDAE; DURNFORD, 1877) IN CHILE: NEW RECORDS AND A REVIEW OF THE STATUS OF PACIFIC POPULATIONS

We report new records of the Dot-winged Crake Porzana spiloptera in southern Chile, an almost unknown species distributed mainly in Argentina and recently discovered in Chile. The occasional capture of a juvenile of the species at Cruces River wetland (39°S), and the analysis of sound recordings obtained to explore the acoustic attributes of urban wetland soundscapes, made it possible to discuss the status of the Pacific populations of the species. The new records show that P. spiloptera has a resident status and suggest that the presence of the species in Chile went historically unnoticed, and that it has been confused with the Black Rail Laterallus jamaicensis. Comprehensive surveys and dedicated research that provide fundamental biological aspects such as the current distribution, population abundance, habitat requirements, and main threats for these secretive rails are urgently needed for their conservation

A Novel Noninvasive Approach Based on SPECT and EEG for the Location of the Epileptogenic Zone in Pharmacoresistant Non-Lesional Epilepsy

Background and objectives: The aim of this study is to propose a methodology that combines non-invasive functional modalities electroencephalography (EEG) and single photon emission computed tomography (SPECT) to estimate the location of the epileptogenic zone (EZ) for the presurgical evaluation of patients with drug-resistant non-lesional epilepsy. Materials and Methods: This methodology consists of: (i) Estimation of ictal EEG source imaging (ESI); (ii) application of the subtraction of ictal and interictal SPECT co-registered with MRI (SISCOM) methodology; and (iii) estimation of ESI but using the output of the SISCOM as a priori information for the estimation of the sources. The methodology was implemented in a case series as an example of the application of this novel approach for the presurgical evaluation. A gold standard and a coincidence analysis based on measures of sensitivity and specificity were used as a preliminary assessment of the proposed methodology to localize EZ. Results: In patients with good postoperative evolution, the estimated EZ presented a spatial coincidence with the resection site represented by high values of sensitivity and specificity. For the patient with poor postoperative evolution, the methodology showed a partial incoherence between the estimated EZ and the resection site. In cases of multifocal epilepsy, the method proposed spatially extensive epileptogenic zones. Conclusions: The results of the case series provide preliminary evidence of the methodology's potential to epileptogenic zone localization in non-lesion drug-resistant epilepsy. The novelty of the article consists in estimating the sources of ictal EEG using SISCOM result as a prior for the inverse solution. Future studies are necessary in order to validate the described methodology. The results constitute a starting point for further studies in order to support the clinical reliability of the proposed methodology and advocate for their implementation in the presurgical evaluation of patients with intractable non-lesional epilepsy.</p

Joint Effect of MCP-1 Genotype GG and MMP-1 Genotype 2G/2G Increases the Likelihood of Developing Pulmonary Tuberculosis in BCG-Vaccinated Individuals

We previously reported that the – 2518 MCP-1 genotype GG increases the likelihood of developing tuberculosis (TB) in non-BCG-vaccinated Mexicans and Koreans. Here, we tested the hypothesis that this genotype, alone or together with the – 1607 MMP-1 functional polymorphism, increases the likelihood of developing TB in BCG-vaccinated individuals. We conducted population-based case-control studies of BCG-vaccinated individuals in Mexico and Peru that included 193 TB cases and 243 healthy tuberculin-positive controls from Mexico and 701 TB cases and 796 controls from Peru. We also performed immunohistochemistry (IHC) analysis of lymph nodes from carriers of relevant two-locus genotypes and in vitro studies to determine how these variants may operate to increase the risk of developing active disease. We report that a joint effect between the – 2518 MCP-1 genotype GG and the – 1607 MMP-1 genotype 2G/2G consistently increases the odds of developing TB 3.59-fold in Mexicans and 3.9-fold in Peruvians. IHC analysis of lymph nodes indicated that carriers of the two-locus genotype MCP-1 GG MMP-1 2G/2G express the highest levels of both MCP-1 and MMP-1. Carriers of these susceptibility genotypes might be at increased risk of developing TB because they produce high levels of MCP-1, which enhances the induction of MMP-1 production by M. tuberculosis-sonicate antigens to higher levels than in carriers of the other two-locus MCP-1 MMP-1 genotypes studied. This notion was supported by in vitro experiments and luciferase based promoter activity assay. MMP-1 may destabilize granuloma formation and promote tissue damage and disease progression early in the infection. Our findings may foster the development of new and personalized therapeutic approaches targeting MCP-1 and/or MMP-1

A functional promoter polymorphism in monocyte chemoattractant protein–1 is associated with increased susceptibility to pulmonary tuberculosis

We examined the distribution of single nucleotide polymorphisms (SNPs) in nitric oxide synthase 2A, monocyte chemoattractant protein–1 (MCP-1), regulated on activation, normal T cell expressed and secreted, and macrophage inflammatory protein–1α genes in tuberculosis patients and healthy controls from Mexico. The odds of developing tuberculosis were 2.3- and 5.4-fold higher in carriers of MCP-1 genotypes AG and GG than in homozygous AA. Cases of homozygous GG had the highest plasma levels of MCP-1 and the lowest plasma levels of IL-12p40, and these values were negatively correlated. Furthermore, stimulation of monocytes from healthy carriers of the genotype GG with Mycobacterium tuberculosis antigens yielded higher MCP-1 and lower IL-12p40 concentrations than parallel experiments with monocytes from homozygous AA. Addition of anti–MCP-1 increased IL-12p40 levels in cultures of M. tuberculosis–stimulated monocytes from homozygous GG, and addition of exogenous MCP-1 reduced IL-12p40 production by M. tuberculosis–stimulated monocytes from homozygous AA. Furthermore, we could replicate our results in Korean subjects, in whom the odds of developing tuberculosis were 2.8- and 6.9-fold higher in carriers of MCP-1 genotypes AG and GG than in homozygous AA. Our findings suggest that persons bearing the MCP-1 genotype GG produce high concentrations of MCP-1, which inhibits production of IL-12p40 in response to M. tuberculosis and increases the likelihood that M. tuberculosis infection will progress to active pulmonary tuberculosis

The STR polymorphism (AAAAT)n within the intron 1 of the tumor protein 53 (TP53) locus in 17 populations of different ethnic groups of Africa, America, Asia and Europe

artículo arbitrado -- Universidad de Costa Rica, Instituto de investigaciones en Salud. 2004The SIR (A.AAAT). within intron 1 of the TP53 Locus was screened in 17 populations from 3 main ethnic groups: Europeans, Asiatics, and Africans. and from the hybrid population of Costa Rica (1968 samples). Three alleles, 126)7 (bp/copies of the repeat), 13118 and 136/9 were the most prevalent in all populations. Other alleles rarely reached frequencies of 10% or higher. Observed heterozygosities ranged between 0.351 and 0.829. Patterns of diversity fit well with both the geographic origin of the samples and the history of the populations screened. A statistical test suggests that single-step mutational events have been the main mechanism producing new alleles at this locus. Fixation indexes (R57) for this marker showed an effect of population subdivision on divergence only within the Asiatic group; they were insensitive at the level of major ethnic groups as well as within Africans and within EuropeansSe estudio el polimorfismo del microsatelite (AAAAI), del intron 1 del gene TP53 en 17 poblaciones de 3 grupos etnicos: europeos, asiaticos, y africanos subsaharianos, asi coma de la poblacion hibrida de Costa Rica (en total 1968 muestras). Tres aides, 12617 (pares de bases/ copias de la repetición), 131/8 y 136/9 fueron los mas frecuentes en todas las poblaciones, aunque se observaron otros alelos usualmente a frecuencias menores al 10%. Las heterocigosis observadas variaron de 0.351 a 0.829. La distribucion de la universidad parece concordar con el origen geográfico de las muestras y con la historia de las poblaciones estudiadas. Una prueba estadística indica que el evento mutacional que mas alelos nuevos produce en ese marcador es el de un solo paso (expansión o contracción de una cola copia de la repeticion). El indice de fijacion R„ mostro los efectos de la subdivision de poblaciones solo dentro del grupo de los asiaticos y mostro falta de sensibilidad cuando los grupos comparados eran de nivetes superiores de clasificacion (europeos, asiaticos, y africanos) o cuando la comparación se hizo entre los grupos mas antiguos (africanos y europeos).Universidad de costa Rica, Instituto de investigaciones en Salud.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Reflexiones universitarias. San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos. Otoño 2015

Los trabajos que aquí se presentan se elaboraron por las y los estudiantes como parte de las actividades del Proyecto de Aplicación Profesional (PAP) “San Pedro Valencia: renovación urbana, saneamiento ambiental y emprendimientos turísticos”, durante el periodo de Otoño de 2015. A lo largo del periodo los autores compartieron sus reflexiones en torno a su percepción sobre el contexto en el que actúa el PAP; sobre las alternativas posibles a la problemática detectada y lo que significa pensar una alternativa; sobre los sujetos con los que se ha interactuado a lo largo de la experiencia de trabajo y sobre el papel del profesionista y del ciudadano en un mundo como el que nos tocó vivir. La obra está compuesta por reflexiones personales de las y los estudiantes que, explorando estas temáticas, comparten sus aprendizajes y observaciones de forma vívida.ITESO, A.C

Spain: Underwater Exploration on a Narrow Continental Shelf

In spite of Spain’s long coastline (nearly 8000 km) and its well-established tradition in underwater archaeology, the prehistoric settlement of the continental shelf is practically unknown with very few finds. Underwater research has focused on naval archaeology and, until very recently, no attempt had been made to look for prehistoric underwater sites. In the past decade,new research projects have been launched to explore selected areas on the Cantabrian shelf and offshore of Gibraltar. This chapter summarises the currently available evidence of submerged prehistoric archaeology and the preliminary results of these new project

Pharmacokinetic Comparability of a Biosimilar Trastuzumab Anticipated from Its Physicochemical and Biological Characterization

Comparability between a biosimilar and its reference product requires the evaluation of critical quality attributes that may impact on its pharmacological response. Herein we present a physicochemical characterization of a biosimilar trastuzumab focused on the attributes related to the pharmacokinetic response. Capillary isoelectrofocusing (cIEF) and cation exchange chromatography (CEX) were used to evaluate charge heterogeneity; glycosylation profiles were assessed through hydrophilic interaction liquid chromatography (HILIC); aggregates content was evaluated through size exclusion chromatography (SEC) while binding affinity to FcRn was evaluated using isothermal titration calorimetry (ITC). The biosimilar trastuzumab and its reference product exhibited a high degree of similarity for the evaluated attributes. In regard to the pharmacokinetic parameters, randomized, double blind, and two-arm parallel and prospective study was employed after the administration of a single intravenous dose in healthy volunteers. No significant differences were found between the pharmacokinetic profiles of both products. Our results confirm that similarity of the critical quality attributes between a biosimilar product, obtained from a different manufacturing process, and the reference product resulted in comparable pharmacokinetic profiles, diminishing the uncertainty related to the biosimilar&apos;s safety and efficacy