Electron Spin Resonance and Thermoluminescence dating of shells and sediments from Sambaqui (shell mound) Santa Marta II, Brazil

In Tupi, the word Sambaqui means “mound of shells”. These archaeological sites are cultural vestiges left by the prehistoric occupation of the Brazilian coast from five to six thousand years ago. Mollusks, fishes, and other marine edible foods were important for the survival of this population. The remains of foods, mainly shells, were heaped up, giving a mound of different proportions, which became part of the landscape of the Brazilian coastal plain. Due to the large number of Sambaquis in Brazil and considering that Sambaqui Santa Marta II, Laguna, SC, has not yet been dated, Electron Spin Resonance (ESR) measurements were performed in aragonite shells collected from different layers of Sambaqui Santa Marta II, starting from the base to the center of the Sambaqui. Radiocarbon analysis by Accelerator Mass Spectrometry (AMS) at Beta Analytic laboratory were also performed for comparison with ESR results. Before measurements, shells were chemically etched, after drying, were pulverized and sieved. The sediments were separated into small portions which were irradiated with gamma radiation from a 60Co source with doses from 5 up to 120 Gy. Ages around 2,000 to 4,000 years have been obtained. The results obtained are consistent with the dates of others Sambaquis of the region, possibly were built at the same time

EPR dating of shells from Malhada Marsh, Rio de Janeiro, Brazil

The formation of the coastal plain of the Brazilian sea is mainly due to the fluctuation of relative sea level in the past. Armação dos Buzios or simply Buzios is a municipality in the microregion of lakes, in the state of Rio de Janeiro. In this region there is a lowland area about two meters above current sea level. This lowland areais also known as coastal plain of Una River. It is expected that during the Holocene period the sea level reached a maximum about 2.5 meters above the current level. During that time billions of mollusks lived and proliferated in the shallow waters around the coastal plain of the Una River. As they died their shells formed a layer in the soil including Malhada Marsh that belongs to the Una River plain. In this study, shells were collected from this region and dated using the techniques of Electronic Paramagnetic Resonance (EPR). Ages from 2480±130 to 4490±270 years were obtained. Radiocarbon dating were performed at the Beta Analytic Lab, USA for comparison with the EPR results. Shells ages obtained are compatible with geological data from the Holocene period relative to past sea level fluctuations

Stabilization of ribozyme-like cis-noncoding rRNAs induces apoptotic and nonapoptotic death in lung cells

Bidirectional non-protein-coding RNAs are ubiquitously transcribed from the genome. Convergent sense and antisense transcripts may regulate each other. Here, we examined the convergent cis-noncoding rRNAs (nc-rRNAs) in A5 and E9 lung cancer models. Sense nc-rRNAs extending from rDNA intergenic region to internal transcribed spacer of around 10 kb in length were identified. nc-rRNAs in sense direction exhibited in vitro characteristics of ribozymes, namely, degradation upon incubation with MgCl2 and stabilization by complementary oligonucleotides. Detection of endogenous cleavage-ligation products carrying internal deletion of hundreds to thousands nucleotides by massively parallel sequencing confirmed the catalytic properties. Transfection of oligonucleotides pairing with antisense nc-rRNAs stabilized both target and complementary transcripts, perturbed rRNA biogenesis, and induced massive cell death via apoptotic and/or nonapoptotic mechanisms depending on cell type and treatment. Oligonucleotides targeting cellular sense transcripts are less responsive. Spontaneously detached cells, though rare, also showed accumulation of nc-rRNAs and perturbation of rRNA biogenesis. Direct participation of nc-rRNAs in apoptotic and nonapoptotic death was demonstrated by transfection of synthetic nc-rRNAs encompassing the rDNA promoter. In sum, convergent cis-nc-rRNAs follow a feed-forward mechanism to regulate each other and rRNA biogenesis. This opens an opportunity to disrupt rRNA biogenesis, commonly upregulated in cancers, via inhibition of ribozyme-like activities in nc-rRNAs

Interferon-α-Conditioned Human Monocytes Combine a Th1-Orienting Attitude with the Induction of Autologous Th17 Responses: Role of IL-23 and IL-12

IFN-α exerts multiple effects leading to immune protection against pathogens and cancer as well to autoimmune reactions by acting on monocytes and dendritic cells. We analyzed the versatility of human monocytes conditioned by IFN-α towards dendritic cell differentiation (IFN-DC) in shaping the autologous T-helper response. Priming of naïve CD4 T cells with autologous IFN-DC in the presence of either SEA or anti-CD3, resulted, in addition to a prominent expansion of CXCR3+ IFN-γ-producing CD4 Th1 cells, in the emergence of two distinct subsets of IL-17-producing CD4 T cells: i) a predominant Th17 population selectively producing IL-17 and expressing CCR6; ii) a minor Th1/Th17 population, producing both IL-17 and IFN-γ. After phagocytosis of apoptotic cells, IFN-DC induced Th17 cell expansion and IL-17 release. Notably, the use of neutralizing antibodies revealed that IL-23 was an essential cytokine in mediating Th17 cell development by IFN-DC. The demonstration of the IFN-DC-induced expansion of both Th1 and Th17 cell populations reveals the intrinsic plasticity of these DC in orienting the immune response and provides a mechanistic link between IFN-α and the onset of autoimmune phenomena, which have been correlated with both IL-17 production and exposure to IFN-α

Generation in vivo of peptide-specific cytotoxic T cells and presence of regulatory T cells during vaccination with hTERT (class I and II) peptide-pulsed DCs

Optimal techniques for DC generation for immunotherapy in cancer are yet to be established. Study aims were to evaluate: (i) DC activation/maturation milieu (TNF-α +/- IFN-α) and its effects on CD8+ hTERT-specific T cell responses to class I epitopes (p540 or p865), (ii) CD8+ hTERT-specific T cell responses elicited by vaccination with class I alone or both class I and II epitope (p766 and p672)-pulsed DCs, prepared without IFN-α, (iii) association between circulating T regulatory cells (Tregs) and clinical responses