Browsing by Author "Repetto, G."

Now showing 1 - 6 of 6
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    Abnormal nodal and global network organization in resting state functional MRI from subjects with the 22q11 deletion syndrome
    (2021) Pelgrim, T.A.D.; Bossong, M.G.; Cuiza, A.; Alliende, L.M.; Mena, C.; Tepper, A.; Ramirez-Mahaluf, J.P.; Iruretagoyena, B.; Ornstein, C.; Fritsch, R.; Cruz, J.P.; Tejos Nunez, Cristian Andres; Repetto, G.; Crossley, N.
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    Aquatic Toxicity Assessment of the Additive 6-Methylcoumarine Using Four Experimental Systems
    (2009) Jos, A.; Repetto, G.; Rios, J. C.; del Peso, A.; Salguero, M.; Camean, A. M.
    The toxicity assessment of chemicals is one of the main issues in the current policies in order to protect the health of the environment and human beings. Food and cosmetic additives have been extensively studied in relation to their toxicity to humans, but data about their ecotoxicological effects are scarce. The aim of this study was to evaluate the toxic effects of the additive 6-methylcoumarine in the aquatic milieu using a test battery comprising experimental model systems from different trophic levels. The inhibition of bioluminiscence was studied in the bacteria Vibrio fischeri (decomposer), the inhibition of growth was evaluated in the alga Chlorella vulgaris (producer) and immobilization was studied in the cladoceran Daphnia magna (first consumer). Finally, several end points were evaluated in the RTG-2 salmonid fish cell line, including neutral red uptake, protein content, methylthiazol tetrazolium salt metabolization, glucose-6-phosphate dehydrogenase activity, lactate dehydrogenase activity and leakage, and morphology. The sensitivity of the test systems employed was as follows: V. fischeri > D. magna > C. vulgaris > RTG-2 cell line. The results show that 6-methylcoumarine is not expected to produce acute toxic effects on the aquatic biota. However, chronic and synergistic effects with other chemicals cannot be excluded and should be further investigated.
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    Bilateral retinoblastoma with one eye manifesting only posterior chamber infiltration and no retinal involvement
    (2016) Shields, C.; Ossandón, D.; Kastner, A.; Zanolli, M.; Solanes, Federica; Pérez, V.; Repetto, G.; Benavides, F.
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    Comparative cytotoxicity of alachlor on RTG-2 trout and SH-SY5Y human cells
    (2006) Fernandez, M.; Rios, J. C.; Jos, A.; Repetto, G.
    The cytotoxic effects of the herbicide alachlor were compared on rainbow trout gonadal RTG-2 and human neuroblastoma SH-SY5Y cell lines. The end points evaluated in both cells after 24, 48, and 72 h of exposure were total protein content (PC), lysosomal function, and mitochondrial's integrity by mitochondrial succinate dehydrogenase (SDH) activity. After 24 h, cytoplasmic membrane integrity by cytosolic lactate dehydrogenase (LDH) leakage and LDH intracellular activity were also studied. In addition, acetylcholinesterase activity (AChE) was quantified in SH-SY5Y cells. The possible biotransformation of alachlor by RTG-2 cells was investigated by analyzing the exposure culture medium by liquid chromatography-mass spectrometry. In RTG-2, EC50 values on PC, lysosomal function, and SDH activity after 24 h exposure ranged from 80 to 95 mu M and decreased to approximately 40 mu M for longer exposure time periods. SH-SY5Y cells were slightly more sensitive than RTG-2 cells, with EC50 values on PC and lysosomal function ranging from 87 to 75 mu M at 24 h and decreasing to 47 mu M and 34 mu M at 72 h, respectively. AChE activity was increased, being the most sensitive marker for SH-SY5Y with an EC50 of 20 mu M at 24 h. The metabolic enzyme SDH was stimulated in SH-SY5Y and reduced in RTG-2 cells. At the studied conditions, no metabolites of alachlor were detected in RTG-2 cultures. In conclusion, the proposed battery approach is an effective screening tool for the safety assessment of environmental contaminants as a complement to fish and animal toxicity procedures.
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    Effect of VKORC1 and CYP2C9 variants on dosage of oral anticoagulants in Chilean individuals
    (2015) Benavides, F.; Grossman, N.; Poggi, Helena; Nieto, E.; Bertran, A.; Araos, D.; Vasquez, M.; Ibarra, I.; Caceres, F.; Lagos Lucero, Sonia Marcela; Espinoza, K.; Repetto, G.
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    WHOOPING-COUGH EPIDEMIOLOGY IN CHILE
    (SOC MEDICA SANTIAGO, 1994) Sánchez Díaz, Ignacio; Repetto, G.; Saenger, A.