Impacto ambiental producido por residuos plásticos

Este trabajo presenta el estudio de los procesos de producción que involucran al plástico como materia prima y la búsqueda de alternativas que permitan disminuir el volumen del material plástico desechado, y al mismo tiempo no sólo minimizar los problemas originados por su disposición final, sino también reutilizarlos como fuente de materia prima y/o energía.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Fermented wheat germ extract inhibits glycolysis/pentoses cycle enzymes and induces apoptosis through poly(ADP-ribose) polymerase activation in Jurkat T cell leukemia tumor cells

The fermented extract of wheat germ, trade name Avemar, is a complex mixture of biologically active molecules with potent anti-metastatic activities in various human malignancies. Here we report the effect of Avemar on Jurkat leukemia cell viability, proliferation, cell cycle distribution, apoptosis, and the activity of key glycolytic/pentose cycle enzymes that control carbon flow for nucleic acid synthesis. The cytotoxic IC(50) concentration of Avemar for Jurkat tumor cells is 0.2 mg/ml, and increasing doses of the crude powder inhibit Jurkat cell proliferation in a dose-dependent fashion. At concentrations higher than 0.2 mg/ml, Avemar inhibits cell growth by more than 50% (72 h of incubation), which is preceded by the appearance of a sub-G(1) peak on flow histograms at 48 h. Laser scanning cytometry of propidium iodide- and annexin V-stained cells indicated that the growth-inhibiting effect of Avemar was consistent with a strong induction of apoptosis. Inhibition by benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone of apoptosis but increased proteolysis of poly(ADP-ribose) indicate caspases mediate the cellular effects of Avemar. Activities of glucose-6-phosphate dehydrogenase and transketolase were inhibited in a dose-dependent fashion, which correlated with decreased (13)C incorporation and pentose cycle substrate flow into RNA ribose. This decrease in pentose cycle enzyme activities and carbon flow toward nucleic acid precursor synthesis provide the mechanistic understanding of the cell growth-controlling and apoptosis-inducing effects of fermented wheat germ. Avemar exhibits about a 50-fold higher IC(50) (10.02 mg/ml) for peripheral blood lymphocytes to induce a biological response, which provides the broad therapeutic window for this supplemental cancer treatment modality with no toxic effects

Modelling prevalence and incidence of fibrosis and pleural plaques in asbestos-exposed populations for screening and follow-up: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>CT-Scan is currently under assessment for the screening of asbestos-related diseases. However, to date no consensus exists as to how to select high-risk asbestos-exposed populations suitable for such screening programs. The objective of this study is to select the most relevant exposure variables for the prediction of pleural plaques and asbestosis in order to guide clinicians in their use of CT-Scan.</p> <p>Methods</p> <p>A screening program of non malignant asbestos-related diseases by CT-scan was conducted among asbestos-exposed volunteers in France. Precise assessments of asbestos exposure were obtained by occupational hygiene measurements and a job-exposure matrix. Several parameters were calculated (time since first exposure, duration, intensity and cumulative exposure to asbestos). Predictive parameters of prevalence and incidence were then estimated by standard logistic and a complementary log-log regression models.</p> <p>Results</p> <p>1011 subjects were recruited in this screening program among them 474 (46.9%) presented with pleural plaques and 61 (6.0%) with interstitial changes compatible with asbestosis on CT-scan. Time since first exposure (p < 0.0001) and either cumulative or mean exposure (p < 0.0001) showed independent associations with both pleural plaques and asbestosis prevalence and pleural plaques incidence. Modelling incidence of pleural plaques showed a 0.8% to 2.4% yearly increase for a mean exposure of 1 f/ml.</p> <p>Conclusion</p> <p>Our findings confirmed the role played by time since first exposure and dose but not duration in asbestos-related diseases. We recommend to include these parameters in high-risk populations suitable for screening of these diseases. Short-periodicity of survey of pleural plaques by CT-Scan seemed not to be warranted.</p

An Enriched European Eel Transcriptome Sheds Light upon Host-Pathogen Interactions with Vibrio vulnificus

Infectious diseases are one of the principal bottlenecks for the European eel recovery. The aim of this study was to develop a new molecular tool to be used in host-pathogen interaction experiments in the eel. To this end, we first stimulated adult eels with different pathogen-associated molecular patterns (PAMPs), extracted RNA from the immune-related tissues and sequenced the transcriptome. We obtained more than 2 x 10(6) reads that were assembled and annotated into 45,067 new descriptions with a notable representation of novel transcripts related with pathogen recognition, signal transduction and the immune response. Then, we designed a DNA-microarray that was used to analyze the early immune response against Vibrio vulnificus, a septicemic pathogen that uses the gills as the portal of entry into the blood, as well as the role of the main toxin of this species (RtxA13) on this early interaction. The gill transcriptomic profiles obtained after bath infecting eels with the wild type strain or with a mutant deficient in rtxA13 were analyzed and compared. Results demonstrate that eels react rapidly and locally against the pathogen and that this immune-response is rtxA13-dependent as transcripts related with cell destruction were highly up-regulated only in the gills from eels infected with the wild-type strain. Furthermore, significant differences in the immune response against the wild type and the mutant strain also suggest that host survival after V. vulnificus infection could depend on an efficient local phagocytic activity. Finally, we also found evidence of the presence of an interbranchial lymphoid tissue in European eel gills although further experiments will be necessary to identify such tissue

Development and Validation of an Automated High-Throughput System for Zebrafish In Vivo Screenings

The zebrafish is a vertebrate model compatible with the paradigms of drug discovery. The small size and transparency of zebrafish embryos make them amenable for the automation necessary in high-throughput screenings. We have developed an automated high-throughput platform for in vivo chemical screenings on zebrafish embryos that includes automated methods for embryo dispensation, compound delivery, incubation, imaging and analysis of the results. At present, two different assays to detect cardiotoxic compounds and angiogenesis inhibitors can be automatically run in the platform, showing the versatility of the system. A validation of these two assays with known positive and negative compounds, as well as a screening for the detection of unknown anti-angiogenic compounds, have been successfully carried out in the system developed. We present a totally automated platform that allows for high-throughput screenings in a vertebrate organism

Effects of cortisol on innate immune responses and on mRNA levels of corticosteroid receptors in rainbow trout

Póster presentado en el 1st International Conference of Fish and Shellfish Immunology celebrado en Vigo del 25 al 28 de junio de 2013Cortisol is a key hormone in the fish stress response with a well known ability to regulate several physiological functions, including carbohydrate metabolism and the immune system. The consequences of cortisol actions in tissues are performed through the corticosteroid receptors (CRs) that have been characterized in fish during the last years. However, data concerning cortisol effects on fish innate immune system and on the transcriptional pattern of the CRs using a more controlled increase in cortisol levels isolated from any other stress related signaling is scarce. Keeping in mind the previous findings, in the present study we injected rainbow trout with slow-release cortisol implants to create medium to high levels of circulating cortisol over extended time periods emulating an acute to chronic stress. Ten days after implantation the cortisol levels in plasma returned to control levels, emulating the period of fish recovery after stress. Glucose and lactate were also returned to control levels corroborating the recovery of the fish after cortisol injection. Thus, the present research work describes the effect of cortisol on selected innate immune responses, such as lysozyme and complement (ACH50) activities, during the recovery period. The mRNA levels of lysozyme and complement C3, factor H and factor B were measured in liver. Furthermore, we present the results concerning the transcriptional levels of the CRs in several organs of trout after 10 days implantation. The results revealed that when plasma cortisol returned to basal levels, lysozyme and ACH50 activities were significantly decreased. These results reflect a latter down-regulatory effect of cortisol on the activity of both ACH50 and lysozyme, which is in agreement with previous findings in stressed fish. In the liver, the mRNA levels of lysozyme, factor B and factor H were also significantly decreased in the recovery period. These changes in mRNA abundances correlate with the plasma data, since both lysozyme and complement activities decreased. Thus, these results suggest that cortisol regulates the expression of lysozyme and complement factors in the liver and that this effect would possibly lead to reduced plasma lysozyme and ACH50 activities. Overall, results support the relevant role of cortisol in modulating key components of the innate immune response in fish, such lysozyme or ACH50 activities, and the expression of their related genes. We also show that even in the recovery period we still found changes in the transcriptional levels of the CRs in gills, spleen and gonads.Peer Reviewe

17p13 (p53 locus), 5q21 (APC locus) and 9p21 (p16 locus) allelic deletions are frequently found in oral exfoliative cytology cells from smoker patients with non-small-cell lung cancer

Molecular cytogenetic and LOH analyses of non-small cell lung cancer (NSCLC) have shown frequent allelic deletions in a variety of chromosomes where tumour suppressor genes are located. Allelic loss at 9p21 (p16 locus), 17p13 (p53) and 5q21(APC) has been frequently described in NSCLC and has also been described in premalignant epithelial lesions of the bronchus and normal bronchial cells. These findings suggest that a tissue field of somatic genetic alterations precedes the histopathological phenotypic changes of carcinoma. Similar changes have been described in oral and laryngeal epithelial tumours associated with smoke exposure. We previously reported frequent LOH at 5q21, 9p21 and TP53 in tumor cells and peritumoral normal bronchial cells from surgically resected NSCLC. We now analyze 96 cases of normal oral exfoliative cytology in which normal epithelial cells were obtained: 43 cases from smoker patients with NSCLC diagnosis, 33 smoker patients with no evidence of malignancy and 20 nonsmoker patients with no evidence of tumour. All groups had a similar age and sex distribution. PCR amplification was performed utilising the specific markers D5S346, D9S157 and TP53. In normal oral mucosae cells from patients with NSCLC, we found that 21% of the informative cases showed LOH at any of the informative cases showed LOH at 5q21, 7.7% at 9p21 and 22.2% at TP53. Within the smoker risk group only one case (4% of the informative cases) showed LOH at TP53, while no LOH was found at 5q21 or 9p21. No LOH was found in non-smokers. In conclusion, our results show that a significant number of patients with NSCLC have LOH at TP53, 5q21 and 9p21 in normal oral mucosae, while LOH at these loci is unusual in similar cells obtained from patients with no evidence of malignancy. Our study demonstrates that LOH studies can detect smoker patients with a mutated genotype in normal epithelial cells. Further prospective studies may confirm whether LOH studies can detect patients with a higher risk of NSCLC