Juan Rı́os

Ecotoxicological evaluation of carbamazepine using six different model systems with eighteen endpoints

The occurrence of pharmaceutically active compounds in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. However, the ecotoxicological effects of pharmaceuticals have still not been researched adequately. Carbamazepine, an anticonvulsant commonly present in surface and groundwater, was studied, using six ecotoxicological model systems with eighteen endpoints evaluated at different exposure time periods. The battery included the immobilization of Daphnia magna, bioluminescence inhibition in the bacterium Vibrio fischeri, growth inhibition of the alga Chlorella vulgaris, and micronuclei induction and root growth inhibition in the plant Allium cepa. Cell morphology, neutral red uptake, total protein content, MTS metabolization, lactate dehydrogenase leakage and activity and glucose-6-phosphate dehydrogenase activity were studied in the salmonid fish cell line RTG-2. The total protein content, LDH activity, neutral red uptake and MTT metabolization in Vero monkey kidney cells were also investigated. The most sensitive system to carbamazepine was the Vero cell line, followed by Chlorella vulgaris, Vibrio fischeri, Daphnia magna, Allium cepa, and RTG-2 cells. EC50 values from 19 microM in Vero cells at 72 h to more than 1200 microM in other systems, were obtained. Comparing the concentrations in water and the toxicity quantified in our assay systems, carbamazepine is not expected to produce acute toxic effects in the aquatic biota under these circumstances, but chronic and synergistic effects with other chemicals cannot be excluded.

CFTR mutations in Chilean cystic fibrosis patients

An analysis of five of the most common cystic fibrosis (CF) mutations worldwide (ΔF-508, R-553X, G-551D, N-1303K and G-542X) was performed in 36 Chilean patients. Polymerase chain reaction (PCR) amplification of the DNA followed by allele specific restriction enzyme analysis was used for detection. The overall frequencies of the mutations in the chromosomes analyzed were 29.2% for ΔF-508 and 4.2% for R-553X (n=72). The G-542X, G-551D and N-1303 K mutations were absent in the Chilean sample. Our data suggest however that ΔF-508 is not the most common CF mutation in Chilean patients. ΔF-508 and R-553X account for only 33.4% of the alleles; 66.6% of them do not respond to the probes used and still remain uncharacterized.

Cracking in sweet cherries: A comprehensive review from a physiological, molecular, and genomic perspective

Rain-induced cracking in fruits of sweet cherry (Prunus avium L.) is a problem in most producing areas of the world and causes significant economic losses. Different orchard management practices have been employed to reduce the severity of this problem, although a complete solution is not yet available. Fruit cracking is a complex phenomenon and there are many factors that seem to be involved in its development. During the last decade, genomic and biochemical approaches have provided new insights on the different mechanisms that could be involved in the differential susceptibility shown by commercial cultivars. For instance, sweet cherry genome and transcriptome sequencing information have provided new opportunities to study the expression and structure of genes involved in cracking, which may help in the development of new tolerant cultivars. The present review summarizes, discuss, and integrate most of the recently generated information in cultural practices, physiology, biochemistry, and genetics in relation to cracking in sweet cherries.

VINCULOS DE PARENTESCO POR VIA MATERNA ENTRE LOS ÚLTIMOS DESCENDIENTES DE LA ETNIA KAWÉSQAR Y ALGUNOS ENTIERROS EN LOS CANALES PATAGÓNICOS: EVIDENCIA DESDE EL ESTUDIO DE LINAJES MITOCONDRIALES

This work presents the results obtained from mitochondrial DNA study of Kawesqar skeletal samples from Englefield island, Cueva de la Cruz, Captain Aracena island and Canal Maule-1; and living individuals of Kawesqar group. The results show a great similarity between the mitochondrial DNA sequences of both living individuals and the old samples. The comparison with other published sequences for south American aboriginal populations confirms the results and strongly suggests that there is a maternal kinship between the samples and the current Kawesqar.