Time filter

Source Type

Carnese F.R.,University of Buenos Aires | Mendisco F.,French National Center for Scientific Research | Mendisco F.,Institute Of Medecine Legale | Keyser C.,Institute Of Medecine Legale | And 5 more authors.
American Journal of Physical Anthropology | Year: 2010

Ancient DNA recovered from 21 individuals excavated from burial sites in the Pampa Grande (PG) region (Salta province) of North-Western Argentina (NWA) was analyzed using various genetic markers (mitochondrial DNA, autosomal STRs, and Y chromosomal STRs). The results were compared to ancient and modern DNA from various populations in the Andean and North Argentinean regions, with the aim of establishing their relationships with PG. The mitochondrial haplogroup frequencies described (11% A, 47% B, and 42% D) presented values comparable to those found for the ancient Andean populations from Peru and San Pedro de Atacama. On the other hand, mitochondrial and Y chromosomal haplotypes were specific to PG, as they did not match any other of the South American populations studied. The described genetic diversity indicates homogeneity in the genetic structure of the ancient Andean populations, which was probably facilitated by the intense exchange network in the Andean zone, in particular among Tiwanaku, San Pedro de Atacama, and NWA. The discovery of haplotypes unique to PG could be due to a loss of genetic diversity caused by recent events affecting the autochthonous populations (establishment of the Inca Empire in the region, colonization by the Europeans). © 2009 Wiley-Liss, Inc. Source

Di Virgilio A.L.,National University of La Plata | Rivadeneira J.,National University of La Plata | Rivadeneira J.,CONICET | Muglia C.I.,National University of La Plata | And 7 more authors.
BioMetals | Year: 2011

The complex of vanadyl(IV) cation with oxodiacetate, VO(oda) caused an inhibitory effect on the proliferation of the human colon adenocarcinoma cell line Caco-2 in the range of 25-100 μM (P < 0.001). This inhibition was partially reversed by scavengers of free radicals. The difference in cell proliferation in the presence and the absence of scavengers was statistically significant in the range of 50-100 μM (P < 0.05). VO(oda) altered lysosomal and mitochondria metabolisms (neutral red and MTT bioassays) in a dose-response manner from 10 μM (P < 0.001). Morphological studies showed important transformations that correlated with the disassembly of actin filaments and a decrease in the number of cells in a dose response manner. Moreover, VO(oda) caused statistically significant genotoxic effects on Caco-2 cells in the low range of concentration (5-25 μM) (Comet assay). Increment in the oxidative stress and a decrease in the GSH level are the main cytotoxic mechanisms of VO(oda). These effects were partially reversed by scavengers of free radicals in the range of 50-100 μM (P < 0.05). Besides, VO(oda) interacted with plasmidic DNA causing single and double strand cleavage, probably through the action of free radical species. Altogether, these results suggest that VO(oda) is a good candidate to be evaluated for alternative therapeutics in cancer treatment. © 2011 Springer Science+Business Media, LLC. Source

Gaya-Vidal M.,University of Barcelona | Gaya-Vidal M.,University Paul Sabatier | Moral P.,University of Barcelona | Saenz-Ruales N.,University Paul Sabatier | And 7 more authors.
American Journal of Physical Anthropology | Year: 2011

Two Bolivian samples belonging to the two main Andean linguistic groups (Aymaras and Quechuas) were studied for mtDNA and Y-chromosome uniparental markers to evaluate sex-specific differences and give new insights into the demographic processes of the Andean region. mtDNA-coding polymorphisms, HVI-HVII control regions, 17 Y-STRs, and three SNPs were typed in two well-defined populations with adequate size samples. The two Bolivian samples showed more genetic differences for the mtDNA than for the Y-chromosome. For the mtDNA, 81% of Aymaras and 61% of Quechuas presented haplogroup B2. Native American Y-chromosomes were found in 97% of Aymaras (89% hg Q1a3a and 11% hg Q1a3*) and 78% of Quechuas (100% hg Q1a3a). Our data revealed high diversity values in the two populations, in agreement with other Andean studies. The comparisons with the available literature for both sets of markers indicated that the central Andean area is relatively homogeneous. For mtDNA, the Aymaras seemed to have been more isolated throughout time, maintaining their genetic characteristics, while the Quechuas have been more permeable to the incorporation of female foreigners and Peruvian influences. On the other hand, male mobility would have been widespread across the Andean region according to the homogeneity found in the area. Particular genetic characteristics presented by both samples support a past common origin of the Altiplano populations in the ancient Aymara territory, with independent, although related histories, with Peruvian (Quechuas) populations. © 2011 Wiley-Liss, Inc. Source

De Luca J.C.,CONICET | Lopez-Larraza D.M.,Instituto Multidisciplinario Of Biologia Celular Imbice
International Journal of Low Radiation | Year: 2013

The goals of this study were to determine whether cysteamine, β-mercaptohetanol and glutathione protect CHO K1 cells against chromosomal aberrations induced by low doses of X-radiation, as well as whether radiation protection is related to physical properties of those thiols. Experimental design included four different treatments: (a) control, (b) cells treated with 5 mM of each thiol, (c) cells treated with 100 mGy of X-rays and (4) cells treated with 5 mM of each thiol and 100 mGy X-rays. In combined treatment, all thiols were added 30 min before irradiation. Thiols remained until cell sacrifice (18 h). Maximum protection was afforded by cysteamine, the minimum protection was produced by glutathione while β-mercaptohetanol did not show radioprotection effect. These results are consistent with the electrical charges and chemical structure of the three thiols and might be explained by the lower or higher access to DNA. Copyright © 2013 Inderscience Enterprises Ltd. Source

Miranda G.E.,National University of the South | Miranda G.E.,Instituto Multidisciplinario Of Biologia Celular Imbice | Abrahan C.E.,National University of the South | Agnolazza D.L.,National University of the South | And 2 more authors.
Investigative Ophthalmology and Visual Science | Year: 2011

Purpose. Simple sphingolipids control crucial cellular processes in several cell types. Previous work demonstrated that sphingolipids, such as ceramide, sphingosine, and sphingosine-1-phosphate, are key mediators in the regulation of survival, differentiation, and proliferation of retina photoreceptors. Ceramide-1-phosphate (C1P) regulates growth and survival in several cell types; however, little is known concerning its functions in the retina. Whether C1P also participates in controlling photoreceptor development was also explored. Methods. Rat retina neuronal cultures were supplemented with 1 to 10 μM C1P. Proliferation was determined by evaluating 5-bromo-2-deoxyuridine (BrdU) uptake and the number of mitotic figures and differentiation by evaluating opsin and peripherin expression by immunocytochemistry and Western blot. Apoptosis was inhibited with the pan caspase inhibitor ZVADFMK and evaluated by TUNEL assay, propidium iodide/annexin V, and DAPI labeling. Preservation of mitochondrial membrane potential was evaluated. Results. C1P enhanced BrdU uptake and increased mitosis in retinal progenitors. C1P addition advanced photoreceptor differentiation, enhancing opsin and peripherin expression and stimulating development of the apical processes in which these proteins were concentrated. In the absence of these trophic factors, photoreceptors degenerated after 4 days in vitro, and at day 6, almost 50% of photoreceptors were apoptotic. C1P decreased photoreceptor apoptosis, reducing this percentage by half. Inhibiting caspase activity reduced photoreceptor apoptosis in the controls, but did not increase opsin expression, implying that C1P has separate effects on differentiation and survival. Conclusions. These results suggest for the first time that C1P is a novel mediator that has multiple functions in photoreceptors, initially regulating their proliferation and then promoting their survival and differentiation. © 2011 The Association for Research in Vision and Ophthalmology, Inc. Source

Discover hidden collaborations