Myrna Sabanero-López

Isolation and some properties of a glycoprotein of 70 kDa (Gp70) from the cell wall of Sporothrix schenckii involved in fungal adherence to dermal extracellular matrix

Sporothrix schenckii is the etiological agent of sporotrichosis, a subcutaneous mycosis and an emerging disease in immunocompromised patients. Adherence to target cells is a prerequisite for fungal dissemination and systemic complications. However, information on the cell surface components involved in this interaction is rather scarce. In this investigation, the extraction of isolated cell walls from the yeast phase of S. schenckii with SDS and separation of proteins by SDS-PAGE led to the identification of a periodic acid-Schiff (PAS)-reacting 70 kDa glycoprotein (Gp70) that was purified by elution from electrophoresis gels. The purified glycopeptide exhibited a pI of 4.1 and about 5.7% of its molecular mass was contributed by N-linked glycans with no evidence for O-linked oligosaccharides. Confocal analysis of immunofluorescence assays with polyclonal antibodies directed towards Gp70 revealed a rather uniform distribution of the antigen at the cell surface with no distinguishable differences among three different isolates. Localization of Gp70 at the cell surface was confirmed by immunogold staining. Gp70 seems specific for S. schenckii as no immunoreaction was observed in SDS-extracts from other pathogenic and non-pathogenic fungi. Yeast cells of the fungus abundantly adhered to the dermis of mouse tails and the anti-Gp70 serum reduced this process in a concentration-dependent manner. Results are discussed in terms of the potential role of Gp70 in the host-pathogen interaction.

Bursera fagaroides, effect of an ethanolic extract on ornithine decarboxylase (ODC) activity in vitro and on the growth of Entamoeba histolytica.

The effect of an ethanolic extract from the stem bark of Bursera fagaroides on ornithine decarboxylase (ODC) activity in vitro and on the growth of Entamoeba histolytica was evaluated. For this purpose, increasing concentrations of the extract, up to 8.0mg/mL, were added to amoeba cultures or ODC reaction mixtures, which were incubated at 37 degrees C. Metronidazole and G418 were added as controls. After 1.5 and 72 h, the ODC activity in vitro and growth, respectively, were determined. Results revealed a strong inhibition of growth with IC(50) values on the order of 0.05 mg/mL. ODC activity, on the other hand, was inhibited by 12% and 50% at concentrations of 4.0 and 8.0mg/mL, respectively.

Human Lung Cancer Cell Line A-549 ATCC Is Differentially Affected by Supranutritional Organic and Inorganic Selenium

The effects of organic and inorganic forms of selenium (Se) on human cells have been extensively studied for nutritional concentrations; however, to date, little is known about the potential toxicity at supranutritional levels. In the present study we determined the effects of sodium selenite (SSe) and selenomethionine (SeMet) on cell growth and intracellular structures in lung cancer cells exposed at Se concentrations between 0 and 3 mM. Our results showed that SSe affected cell growth more rapidly than SeMet (24 h and 48 h, resp.). After 24 h of cells exposure to 0.5, 1.5, and 3 mM SSe, cell growth was reduced by 10, 50, and 60%, as compared to controls. After 48 h, nuclear fragmentation was evident in cells exposed to SSe, suggesting an induction to cell death. In contrast, SeMet did not affect cell proliferation, and the cells were phenotypically similar to controls. Microtubules and microfilaments structures were also affected by both Se compounds, again SSe being more toxic than SeMet. To our knowledge, this is the first report on the differential effects of organic and inorganic Se in supranutritional levels in lung cancer cells.

PEMF on Neuroblastoma Cells Previously Exposed to Antidepressants

Interaction between magnetic field and living systems is inevitable; in fact, we are immersed in an ocean of magnetic field due to the magnetic field of the earth and the technology developments. Interaction between magnetic field and living systems is inevitable; in fact, we are immersed in an ocean of magnetic field due to the magnetic field of the earth and the technology developments, this one already have medical applications, currently, the pulsed electromagneticmagnetic fields (PEMF) are an alternative option for the treatment of some mental illness as the depression or schizophrenia. In order to have estimation of the side effects from PMF and drugs used for treat this kind of disorders. In this work, it is presented a comparison of the effects of imipramine, a drug for the treatment of depression, and the effects of PMF on cells from the line SHSY5Y, which provide us a representative model of neuronal tissue. The assays were done in both ways, the separately effects and the jointly effects. The imipramine at high dosage for a short period (120 mg/mL, for 20 min) shows cell damage on both, the morphology and the metabolism. Meanwhile, the PMF (50 Hz, 7 mT for 8 h) shows a cell proliferation and a decrease of their metabolism. The jointly assay indicates that the PMF balances the morphological negative effects from imipramine. In the long term these results can impact a therapy that may be more efficient. However, more research is needed in this area

Acetylsalicylic acid impedes human endothelial cell activation mediated by soluble products derived from a human lymphoma

IntroductionAcetylsalicylic acid intake has been reported to reduce the risk of development and dissemination of some tumours. To-date, the mechanism for this protective effect remains unknown.Materials and methodsWe have demonstrated, previously, that soluble products secreted by tumour cells activate human endothelial cells in a manner that is dependent on the nuclear factor-kB (NF-κB) transcription factor. Whether the protection conferred by acetylsalicylic acid is via its effect on cyclo-oxygenase or on the activation of the NF-κB, is unclear.ResultsIn testing this system we observed that acetylsalicylic acid blocked the endothelial activation induced by soluble products secreted by tumour cell by: a) impeding the translocation of NF-κB; b) reducing the expresion of ICAM-1, and c) reducing the capacity of endothelial cells to adhere to the human lymphoma U937.ConclusionThese results can explain, in part, the mechanism by which acetylsalicytic acid impedes the dissemination of malignant tumours.ResumenIntroducciónEn seres humanos, la ingestión de ácido acetilsalicílico reduce el riesgo de, desarrollo tumoral y la diseminación de algunos tumores.Materiales y métodosPreviamente hemos demostrado que los productos solubles secretados por células tumorales activan a las células endoteliales humanas de una manera dependiente del factor de transcripción NF-κB. Actualmente, se desconoce el mecanismo de esta protección, y si está relacionada con los effectos del ácido acetilsalicílico sobre la ciclooxigenasa, o sobre la activación de NF-κB.ResultadosAl probar el efecto del mism, o sobre este sistem a encontramos que bloquea la activación endotelial inducida por productos solubles secretados por células tumorales al: a) interferir con la translocación de NF-κB; b) reducir la expresión de ICAM-1, 1, y c) reducir la capacidad de células endoteliales de adherir al linfoma humano U937.ConclusiónEstos resultados podrían explicar el mecanismo por el cual el ácido acetilsalicílico interfiere con la diseminación de tumores malignos.