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Search Results: 1 - 10 of 236564 matches for " Jose R Sotelo-Silveira "
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Genomic profiling of tumor initiating prostatospheres
Maria Duhagon, Elaine M Hurt, Jose R Sotelo-Silveira, Xiaohu Zhang, William L Farrar
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-324
Abstract: Traditional stem cell medium (SCM) supplemented with Knockout?SR (KO) allows the propagation of monoclonal PSs from cell lines and primary cells. PSs display gene expression and tumorigenicity hallmarks of TICs. Gene expression analysis defined a gene signature composed of 66 genes that characterize LNCaP and patient PSs. This set includes novel prostate TIC growth factors (NRP1, GDF1, JAG1), proteins implicated in cell adhesion and cytoskeletal maintenance, transcriptional regulators (MYCBP, MYBL1, ID1, ID3, FOS, ELF3, ELF4, KLF2, KLF5) and factors involved in protein biosynthesis and metabolism. Meta-analysis in Oncomine reveals that some of these genes correlate with prostate cancer status and/or progression. Reporter genes and inhibitors indicate that the Notch pathway contributes to prostatosphere growth.We have developed a model for the culture of PSs, and provide a genomic profile that support CSCs identity. This signature identifies novel markers and pathways that are predicted to correlate with prostate cancer evolution.There is overwhelming evidence supporting the concept that only a specific group of cells, among the cellular heterogeneity of a tumor, possesses self-renewal and multilineage differentiation potential and is, therefore, responsible for tumor development[1]. These cells, so called "tumor initiating cells" (TICs) or "cancer stem cells" (CSCs), have been documented in most circulating and solid tumors as well as in numerous established cancer cell lines[2]. The expression of adult stem cell surface markers (e.g. CD133, CD44, ESA) as well as the expression of specific embryonic stem cell genes (e.g. OCT3/4, NANOG, SOX2) is one of the hallmarks of the TIC [2]. TICs also display increased potential for anchorage-independent growth, capacity to form spheroids in vitro, and propensity to undergo epithelial-mesenchymal transition. Nevertheless, in the current paradigm, the gold standard property of a TIC is its ability to initiate and generate a tum
Myosin-Va-Dependent Cell-To-Cell Transfer of RNA from Schwann Cells to Axons
José R. Sotelo, Lucía Canclini, Alejandra Kun, José R. Sotelo-Silveira, Lei Xu, Horst Wallrabe, Aldo Calliari, Gonzalo Rosso, Karina Cal, John A. Mercer
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061905
Abstract: To better understand the role of protein synthesis in axons, we have identified the source of a portion of axonal RNA. We show that proximal segments of transected sciatic nerves accumulate newly-synthesized RNA in axons. This RNA is synthesized in Schwann cells because the RNA was labeled in the complete absence of neuronal cell bodies both in vitro and in vivo. We also demonstrate that the transfer is prevented by disruption of actin and that it fails to occur in the absence of myosin-Va. Our results demonstrate cell-to-cell transfer of RNA and identify part of the mechanism required for transfer. The induction of cell-to-cell RNA transfer by injury suggests that interventions following injury or degeneration, particularly gene therapy, may be accomplished by applying them to nearby glial cells (or implanted stem cells) at the site of injury to promote regeneration.
The Trypanosoma cruzi nucleic acid binding protein Tc38 presents changes in the intramitochondrial distribution during the cell cycle
María A Duhagon, Lucía Pastro, José R Sotelo-Silveira, Leticia Pérez-Díaz, Dante Maugeri, Sheila C Nardelli, Sergio Schenkman, Noreen Williams, Bruno Dallagiovanna, Beatriz Garat
BMC Microbiology , 2009, DOI: 10.1186/1471-2180-9-34
Abstract: By using specific antibodies, we found that Tc38 protein from epimastigote extracts participates in complexes with the poly [dT-dG] probe as well as with the universal minicircle sequence (UMS), a related repeated sequence found in maxicircle DNA, and the telomeric repeat. However, we found that Tc38 predominantly localizes into the mitochondrion. Though Tc38 is constitutively expressed through non-replicating and replicating life stages of T. cruzi, its subcellular localization in the unique parasite mitochondrion changes according to the cell cycle stage. In epimastigotes, Tc38 is found only in association with kDNA in G1 phase. From the S to G2 phase the protein localizes in two defined and connected spots flanking the kDNA. These spots disappear in late G2 turning into a diffuse dotted signal which extends beyond the kinetoplast. This later pattern is more evident in mitosis and cytokinesis. Finally, late in cytokinesis Tc38 reacquires its association with the kinetoplast. In non-replicating parasite stages such as trypomastigotes, the protein is found only surrounding the entire kinetoplast structure.The dynamics of Tc38 subcellular localization observed during the cell cycle and life stages support a major role for Tc38 related to kDNA replication and maintenance.Trypanosoma cruzi the protozoan responsible for Chagas disease belongs to a group of organisms that branched very early in eukaryotic evolution. Probably as a consequence of its evolutionary distance from higher eukaryotes, this protozoan shows several unique features. Among them, the mitochondrial DNA forms a unique network structure known as kinetoplast that is composed of two types of topologically catenated circular DNA molecules: maxicircles (20 to 37 kb) and minicircles (0.5 to 2.8 kb). The few dozens of maxicircles bear information equivalent to that of the mtDNA from higher eukaryotes while the several thousand diverse minicircles carry information for RNA editing in the form of guide RNA (gRN
A Model for Video Quality Assessment Considering Packet Loss for Broadcast Digital Television Coded in H.264
Jose Joskowicz,Rafael Sotelo
International Journal of Digital Multimedia Broadcasting , 2014, DOI: 10.1155/2014/242531
Abstract: This paper presents a model to predict video quality perceived by the broadcast digital television (DTV) viewer. We present how noise on DTV can introduce individual transport stream (TS) packet losses at the receiver. The type of these errors is different than the produced on IP networks. Different scenarios of TS packet loss are analyzed, including uniform and burst distributions. The results show that there is a high variability on the perceived quality for a given percentage of packet loss and type of error. This implies that there is practically no correlation between the type of error or the percentage of packets loss and the perceived degradation. A new metric is introduced, the weighted percentage of slice loss, which takes into account the affected slice type in each lost TS packet. We show that this metric is correlated with the video quality degradation. A novel parametric model for video quality estimation is proposed, designed, and verified based on the results of subjective tests in SD and HD. The results were compared to a standard model used in IP transmission scenarios. The proposed model improves Pearson Correlation and root mean square error between the subjective and the predicted MOS. 1. Introduction Television is by far the communications service with higher penetration in society. It reaches every household in many countries of the world. Broadband Internet access does not have such an extended penetration in some countries. While in developing countries 72.4% of households have a TV set, only 22.5% have a computer and only 15.8% have Internet access (compared to 98%, 71%, and 65.6%, resp., in developed countries) [1]. In order to care for bringing quality to the people through communications services it is essential to be concerned about the quality delivered by the TV services. Nowadays great attention is given to Digital Television (DTV). Many countries in the world have already made the so-called “analog switch-off” which means that all analog TV transmitters in a given country or city are finally switched off, paving the way to new usage of the spectrum. Some other countries are planning it for some time between 2015 and 2020. The completion of the analog switch-off will imply the end of the migration from analog TV to DTV. The above mentioned applies to Terrestrial Digital Television, that is, the traditional free-to-air TV service. However, there are also some other transmitting mediums used for TV services, mainly for Pay TV, which were digitalized many years ago. Those are the cases of satellite TV and cable TV. Besides,
Fetal cardiotocography before and after water aerobics during pregnancy
Carla Silveira, Belmiro G Pereira, Jose G Cecatti, Sergio R Cavalcante, Rosa I Pereira
Reproductive Health , 2010, DOI: 10.1186/1742-4755-7-23
Abstract: In a non-randomized controlled trial, 133 previously sedentary pregnant women participated in multiple regular sessions of water aerobics in a heated swimming pool. Cardiotocography was performed for 20 minutes before and just after the oriented exercise. Cardiotocography patterns were analyzed pre- and post-exercise according to gestational age groups (24-27, 28-31, 32-35 and 36-40 weeks). Student's t and Wilcoxon, and McNemar tests were used, respectively, to analyze numerical and categorical variables.No significant variations were found between pre- and post-exercise values of fetal heart rate (FHR), number of fetal body movements (FM) or accelerations (A), FM/A ratio or the presence of decelerations. Variability in FHR was significantly higher following exercise only in pregnancies of 24-27 weeks.Moderate physical activity in water was not associated with any significant alterations in fetal cardiotocography patterns, which suggests no adverse effect on the fetus.In the past, the practice of physical activity by pregnant women has always been surrounded by uncertainties and was considered a taboo. Sedentary approaches were encouraged and women were counseled to stay off their feet as much as possible. In addition, the fear that women could acquire genital infections from immersion in water caused health professionals to discourage this activity [1]. Currently, there is an almost general recognition among health professionals that moderate exercise offers no risks to pregnant women as long as there are no obstetrical complications or preexisting conditions, such as vaginal bleeding, arterial hypertension or cervical incompetence [2].In 1985, the American College of Obstetricians and Gynecologists (ACOG) issued the opinion that exercise during low-risk pregnancy is safe for the mother and fetus when maternal heart rate does not exceed 140 beats per minute for more than 15 minutes [3]. Recent guidelines issued by the ACOG recommend caution and medical supervision
Conservación de las raíces frescas de la yuca (Manihot esculenta Crantz) aplicándole el proceso de parafinado
R. Sotelo,G. Acevedo
Nexo , 2008,
Abstract: El objetivo del trabajo fue determinar el efecto del proceso de parafinado en la conservación de la calidad de las raíces de yuca incluyendo la calidad morfológica, fisiológica, culinaria y el deterioro microbiano. Las raíces de la yuca fueron obtenidas de distintos parcelas cultivadas y fueron cosechadas en diferentes períodos de tiempo. Para su evaluación, algunos lotes se sometieron al proceso de parafinado y otros se dejaron sin parafina. Se analizaron muestras de material de raíces en laboratorio para determinar la presencia de patógenos que provocan el deterioro microbiano. Los resultados mostraron en la raíces parafinadas valores medios de deterioro fisiológico de 4 % a 5 % hasta los 28 días de almacenamiento, en comparación con las muestras de raíces sin parafinar con valores medio de deterioro de 18 % a 19 %, en un período de 10 a 13 días de almacenamiento. Asimismo, se encontró la bacteria Erwinia spp. como elemento del deterioro microbiano. El parafinado provoca retardación en el deterioro, logrando un incremento considerable en la conservación de la raíces.
Water aerobics II: maternal body composition and perinatal outcomes after a program for low risk pregnant women
Sergio R Cavalcante, Jose G Cecatti, Rosa I Pereira, Erica P Baciuk, Ana L Bernardo, Carla Silveira
Reproductive Health , 2009, DOI: 10.1186/1742-4755-6-1
Abstract: A randomized controlled trial carried out in 71 low-risk sedentary pregnant women, randomly allocated to water aerobics or no physical exercise. Maternal body composition and perinatal outcomes were evaluated. For statistical analysis Chi-square, Fisher's or Student's t-tests were applied. Risk ratios and their 95% CI were estimated for main outcomes. Body composition was evaluated across time using MANOVA or Friedman multiple analysis.There were no significant differences between the groups regarding maternal weight gain, BMI or percentage of body fat during pregnancy. Incidence of preterm births (RR = 0.84; 95%CI:0.28–2.53), vaginal births (RR = 1.24; 95%CI:0.73–2.09), low birthweight (RR = 1.30; 95%CI:0.61–2.79) and adequate weight for gestational age (RR = 1.50; 95%CI:0.65–3.48) were also not significantly different between groups. There were no significant differences in systolic and diastolic blood pressure and heart rate between before and immediately after the water aerobics session.Water aerobics for sedentary pregnant women proved to be safe and was not associated with any alteration in maternal body composition, type of delivery, preterm birth rate, neonatal well-being or weight.The association between good health and physical activity is not recent. Studies report that both the public in general and scientists and physicians in particular are concerned with the regular practice of moderate physical exercise, which is believed to contribute towards the length and quality of life [1-3]. Today, different age groups, genders, ethnic groups and especially pregnant women are concerned with physical well-being, and as there were no data in humans to justify that exercise should be limited during pregnancy, this explains, in part, why exercise programs for pregnant women are becoming increasingly popular [4].During pregnancy, considerable anatomical and physiological changes take place in the expectant mother, including weight gain, and these changes are necessa
Participa??o do setor privado na governan?a ambiental global: Evolu??o, contribui??es e obstáculos
Andrade, Jose Célio Silveira;
Contexto Internacional , 2009, DOI: 10.1590/S0102-85292009000200001
Abstract: this article intends to study the evolution of the participation of the private sector in the global environmental governance (geg), identifying the contributions and the main obstacles faced by this actor. to achieve this goal, emphasis was done on qualitative research strategy based on analysis of academic literature, working papers, diagnostics and institutional reports. it shows that the participation of business in the geg occurs through the process of formation and implementation of international environmental regimes and the development of hybrid and private environmental governance schemes. in conclusion, this article defends that the private sector can contribute to the effectiveness of geg, however, there are several obstacles to a stronger participation of this actor in the world ecopolitics.
Howard Gest. Microbes: An invisible Universe
Jose R
Indian Journal of Medical Microbiology , 2005,
Abstract:
Palyosulfonoceramides A and B: Unique Sulfonylated Ceramides from the Brazilian Zoanthids Palythoa caribaeorum and Protopalyhtoa variabilis
Jose Gustavo L. Almeida,Ana Isabel V. Maia,Diego V. Wilke,Edilberto R. Silveira,Raimundo Braz-Filho,James J. La Clair,Leticia V. Costa-Lotufo,Otília Deusdenia L. Pessoa
Marine Drugs , 2012, DOI: 10.3390/md10122846
Abstract: The zoanthids Palythoa caribaeorum and Protopalythoa variabilis are among the most abundant marine species along the Brazilian coast. We now report the isolation and structure elucidation of two unprecedented sulfonylated ceramides, palyosulfonoceramide A ( 1) and palyosulfonoceramide B ( 2) from specimens collected off Brazil’s northeastern coast. The structures of 1 and 2 were established using a combination of NMR analyses, including: evaluation of 1H, 13C, 1H– 1H COSY, 1H– 13C HSQC, 1H– 13C HMBC, and 1H– 15N HMBC NMR spectra, high-resolution mass spectrometry and chemical degradation. In addition, we also isolated the corresponding known ceramides, N-((2 S,3 R,4 E,8 E)-1, 3-dihydroxyoctadeca-4,8-dien-2-yl)-hexadecanamide ( 3) and N-((2 S,3 R,4 E)-1,3-dihydroxy octadeca-4-en-2-yl)-hexadecanamide ( 4), which provided further support for the assignments of 1 and 2.
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