Julián Londoño

The prevalence of germ-line TP53 mutations in women diagnosed with breast cancer before age 30

Germ-line mutations in the TP53 gene are rare, but predispose women to a range of cancer types, including early-onset breast cancer. Breast cancers in women from families with the Li-Fraumeni syndrome often occur before age 30. The prevalence of deleterious TP53 mutations in unselected women with early-onset breast cancer is not precisely known. If mutations were found to be sufficiently common, it might be prudent to offer genetic testing to affected women in this age group. We screened the entire TP53 gene in the germ-line DNA from 95 women of various ethnic groups who were diagnosed with breast cancer before age 30, and who had previously been found to be negative for BRCA1 and BRCA2 mutations. No TP53 mutation was found. This study does not support a policy that TP53 testing should be offered routinely to unselected women with early-onset breast cancer in the absence of a family history of cancer.

Monitoring accumulation of bioactive compounds in seeds and cell culture of Theobroma cacao at different stages of development

In recent years, polyphenols from Theobroma cacao and other plant sources have been widely used as natural chemopreventive agents due to their antioxidant properties. Some studies indicate that the polyphenol content, particularly flavan-3-ols, is strongly correlated to the intensity of the purple color in fresh cocoa seeds. However, no visual marker of polyphenol synthesis has been reported in this plant species. The purposes of this study were to monitor the production of certain flavan-3-ols and methylxanthines by chemical and histological analysis in three ecotypes of cacao grown in Colombia at three developmental stages and to compare the result to a standard of polyphenol production over time for two T. cacao cell lines grown in vitro. According to the observations made, polyphenols are stored exclusively in polyphenolic cells that are randomly located between cells that form cotyledon tissue and their biosynthesis is directly proportional to the seed age. Polyphenols are accumulated in the cytoplasm of this kind of cells, which is moved to the protoplasm, coating the cytoplasmic membrane, possibly due to the growth of the vacuole during maturation. In cell culture, polyphenol accumulation is also associated with a particular cell type that is immersed in a group of non-polyphenolic cells. However, it is only possible to identify these cells using destructive staining techniques, which do not allow application of this separation method for obtaining homogenous cell lines. Despite this finding, in this study, it was possible to identify a macroscopic color marker of populations that are rich in dark beige polyphenols, which could be used to screen cell populations.

Survey of gastrointestinal parasites, liver flukes and lungworm in feces from dairy cattle in the high tropics of Antioquia, Colombia

A cross sectional study was undertaken to determine the prevalence and intensity of parasitic infections in dairy cattle in the high tropics of Colombia. A total of 1003 rectal samples were collected from dairy cows at 29 farms between May and June 2014 to represent the number of farms, age groups, and size of the 65,000-cow population in the municipality of San Pedro de los Milagros. Coprological techniques were used to detect gastrointestinal nematodes, liver flukes, coccidian oocysts, and first larval stage counts of Dictyocaulus viviparus. In order of decreasing prevalence, the following parasites were detected: coccidial oocyst (36.7%; 95% CIs, 31.6–42.7), strongyle nematodes (31.6%, 27.8–35.4), liver flukes (30.9%, 21.5–37.5), cestodes (8.4%, 7.1–9.7), and D. viviparus (5.4%, 3.4–7.5). Co-infections by all possible combinations of the three most predominant groups occurred in 11 to 15% of the animals. There were significant differences in infection rates between age groups, with higher risk of liver fluke infection in animals older than 1 year of age (odds ratio (OR) = 3.2), but lower presence for coccidia and strongyles (OR = 0.19 and 0.51, respectively). For Fasciola hepatica, within-herd prevalences of > 25% in 16 farms and 94 of 281 (33.5%) animals with > 5 eggs per gram (epg) indicate that significant production losses are likely occurring. The variation in the prevalence of gastrointestinal parasites and liver flukes, together with the level of infection among age groups, could be used in integrated management programs to establish selective anthelmintic treatments and select for heritable traits of host resistance. These results serve as a baseline for future studies to determine the success of control measures and should increase awareness that subclinical parasitism is widespread in the livestock sector.

MONOTERPENOS AROMÁTICOS TIMOL Y CARVACROL: APROXIMACIONES DE SU POSIBLE PAPEL EN PROCESOS CLAVES DE LA PATOLOGÍA CARDIOVASCULAR

An imperative event in foam cells generation in the atherosclerosis is the LDL oxidation. When this particle is oxidized they are recognized by macrophage which begins to convert on reactive cells producing growing factor and inducing replication of smooth muscle cells. The glication and oxidative processes increase the LDL electronegativity and its inflammatory effect; therefore inhibit that process as much proteic part as lipid content can retard atherogenic events carried out by this particle. The reduction kinetics of a free radical by the aromatic monoterpenes thymol and carvacrol were compare against BHT. Different methodologies were employing to compare the protection activity of monoterpenes to propose possible mechanism on its incidence on key targets about this pathology.

EFECTO DE LA HESPERIDINA SOBRE LA CAPTACIÓN DE HDL EN CÉLULAS HEPÁTICAS Y EVALUACIÓN DE HESPERIDINA LIPOSOMAL SOBRE LA OXIDACIÓN DE LDL

La hesperidina es un flavonoide con varios reportes de bioactividad. En el presente trabajo se demostro la potencialidad de tres fuentes vegetales para la obtencion industrial de hesperidina, la cual fue probada sobre dos modelos de procesos claves en la patologia cardiovascular: la captacion de HDL por celulas hepaticas y la oxidacion de LDL. Sin embargo, la hesperidina presenta una utilidad farmaceutica limitada debido a su baja solubilidad en agua, por lo tanto se exploro la alternativa de incorporar hesperidina en liposomas encontrando altos porcentajes de encapsulacion y un aumento en la inhibicion de LDL comparada con el compuesto libre