Jesús Olivero

Human exposure to mercury in San Jorge river basin, Colombia (South America)

During May-September 1999 human hair samples were collected from the village of Caimito, a fishing community of the state of Sucre (Colombia), in the San Jorge River basin area, and analyzed for total mercury (t-Hg) by cold vapor atomic absorption spectroscopy. T-Hg was measured in both male and female people aged 15-65 years, whose diet mainly consists of fish collected in nearby marshes. Average hair t-Hg concentration in people from Caimito was 4.91 +/- 0.55 microg/g (n = 94), similar to the value previously detected in fishermen living in the gold mining area, 50 km east. Males had similar t-Hg concentrations (4.31 +/- 0.42 microg/g; n = 56) to females (5.78 +/- 1.21 microg/g; n = 38) and there was no difference in t-Hg levels between groups of different age. Mercury content in hair was weakly but significantly associated (R = 0.20, P = 0.05) with fish consumption.

Mercury in environmental samples from a waterbody contaminated by gold mining in Colombia, South America

Environmental samples from a marsh, which receives mercury discharges from a gold mine in Colombia (South America), were evaluated for total mercury content. Mercury concentrations were analyzed in sediments, macrophytes and fish species from different trophic levels. The Mean mercury levels in sediments oscillated between 140 and 355 micrograms/kg whereas in the macrophyte Eichornia crassipes levels were between 219 and 277 microgram/kg with practically no interseasonal variations. The mercury content in the muscle of fish varied depending on the position in the trophic chain and the feeding habits of each species, oscillating between non-detectable (< 7.4 microgram/kg) and 1084 micrograms/kg. Seasonal variations were only observed in fish species whose habitats are mostly the bottom sediment. The presence of mercury in some fish appeared to be the result of bioaccumulation rather than a biomagnification processes. This was clearly evidenced in the detritivorous species Triportheus magdalenae which obtain their food within the sediments and whose mercury concentrations were significantly higher when compared to the other species including carnivorous. The relatively low mercury concentrations found in fish may be due to both the dispersion of the contaminant once it reaches the waterbody and the migrational characteristics of the fish species.

Prediction of the gas chromatographic relative retention times of flavonoids from molecular structure

Abstract Quantitative structure-retention relationships have been formulated for the gas chromatographic behaviour of 49 flavonoids in an apolar column, including flavones, flavonols, flavanones and a chalcone. Topological, geometric and electronic descriptors were obtained for model generation. Relationships between descriptors and the inverse form of the relative retention times of flavonoids relative to hispidulin were established using linear multiple regression. The best descriptors included in the model were 1/( 3 X c − 3 X c V ), and the sum of the values of the charges for the hydroxyl hydrogens. The predictive model had a correlation coefficient of 0.975 and a standard error of estimation of 0.120.

Mercurio en cabello de diferentes grupos ocupacionales en una zona de minería aurifera en el Norte de Colombia

Hair mercury analysis was carried out on a sample of 219 people living in the main gold mining zone of Colombia, 27 inhabitante of Cartagena City being taken as control sample. For data analysis the sample was divided by occupation and the corresponding the hair mercury concentrations (mean +/- SD) were found to be 5.23 +/- 5.78, 2.83 +/- 3.27, 2.4 +/- 2.02 and 1.33 +/- 0.74 micrograms/g for fishermen, miners, people of various other activities and the control sample, respectively. According to variance analysis and the Newman Keuls test, there were significant differences (p < 0.01) between the mercury concentrations for fishermen and those for the other groups. No significant differences were found for hair mercury and sex, non was any correlation with age detected; however, a low positive correlation (R = 0.15, p < 0.01) with the frequency of the consumption of fish was noted. The main symptoms of mercury poinsoning observed in the persons exposed were headache, oral lesions, metalic taste, loss of memory, and irritability.Analisis de mercurio en cabello fue realizado a 219 personas que habitan en la principal zona de mineria del oro en Colombia, tomando 27 personas de la ciudad de Cartagena, como muestra Control. Para el analisis de los datos, la muestra estudiada se dividio de acuerdo con la ocupacion de las personas, encontrandose concentraciones medias (±DE) de 5,23±5,78, 2,83±3,27, 2,40±2,02 y 1,33±0,74 µg/g de mercurio en cabello, para pescadores, mineros, personas dedicadas a otras actividades y grupo control respectivamente. De acuerdo con el analisis de varianza y el test de Newman Keuls, existe diferencia significativa (p<0,01) para las concentraciones de mercurio observadas entre pescadores y los demas grupos. No se presentaron diferencias significativas de mercurio en cabello de acuerdo con el sexo, tampoco se detecto correlacion con la edad, no obstante se observo una ligera correlacion positiva (R=0,15, p<0,01) con la frecuencia en el consumo de pescado. Los principales sintomas de intoxicacion mercurial encontrados entre la poblacion expuesta fueron cefalea, nauseas, lesiones orales, gusto metalico, perdida de memoria e irritabilidad.

Abstract B256: Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer cells.

We have previously shown that a series of brominated and chlorinated analogs of 3,39-diindolylmethane (DIM) can inhibit can induce apoptosis and necrosis in androgen-dependent and androgen-independent prostate cancer cells and that addition of bromine to the 4 and 4’ position of the indole ring of DIM maximally increases the potency of the anticancer compound. To understand the upstream events leading to the activation of caspases in response to treatment with ring-DIMs in androgen-dependent LNCaP and androgen-independent LNCaP C4-2B cells by monitoring the onset of endoplasmic reticulum (ER) stress and the dysregulation of mitochondrial respiration. We found that 4,49-dibromo- and 7,79-dichloroDIM and DIM itself induced ER stress-dependent upregulation of CHOP, ATF4, and GRP78, while only 4,49-dibromo and 7,79-dichloroDIM induced phosphorylation of eIF2alpha and JNK. Both ER stress and loss of mitochondrial membrane potential were observed after treatment with 4,49-dihaloDIMs and DIM, but not 7,79-dihaloDIMs within 1 hour of exposure, before the appearance of later stage apoptotic events such as condensed chromatin. Salubrinal inhibited cell death induced by 4,49-dihaloDIMs, but facilitated cell death induced by 7,79-dihaloDIMs or DIM. Interestingly, salubrinal did not increase eIF2alpha phosphorylation after co-treatment with either DIM or ring-DIMs. However, it did restore mitochondrial membrane potential in cells treated with 4,49dihaloDIMs and further decreased mitochondrial activity after co-treatment with 7,79-dihaloDIMs or DIM. Moreover, cyclosporin A inhibited cell death induced by both 4,4’-dihalo and 7,7’-dihaloDIMs but not DIM. Taken together, these data suggest that the ring-DIMs induce cell death via mitochondrial dysfunction and ER stress, and that because salubrinal either stimulates or inhibits cell death in combination with specific ring-DIMs, its effects are related to mitochondrial membrane integrity and not to phosphorylation of eIF2alpha. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B256. Citation Format: Alexander A. Goldberg, Diana Montes-Grajales, Jesus Olivero, Adam Beach, Vladimir Titorenko, Steven Safe, Thomas Sanderson. Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B256.