37 research outputs found

    Expresión de citoquinas TH1 y TH2 en cáncer cervical avanzado y su relación a la presencia y expresión de los oncogenes E6 y E7 de HPV I6

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    Tesis (Doctor en Ciencias con Especialidad en Microbiología) U.A.N.L.UANLhttp://www.uanl.mx

    Comparative Evaluation of Phenoloxidase Activity in Different Larval Stages of Four Lepidopteran Pests After Exposure toBacillus thuringiensis

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    Microbial entomopathogen–based bioinsecticides are recognized as alternatives to synthetic pesticides. Insects defend themselves against microbial pathogens by innate mechanisms, including increased phenoloxidase (PO) activity, but its relationship with microbial bioinsecticides efficacy is little known. This study evaluated the differences in PO activity at different developmental stages of the tobacco budworm Heliothis virescens Fabricius (Lepidoptera: Noctuidae), Indian meal moth Plodia interpunctella (Hübner) (Pyralidae), beet armyworm Spodoptera exigua (Hübner) (Noctuidae), and cabbage looper Trichoplusia ni (Hübner) (Noctuidae). Additionally, 2nd- and 4th-instars were exposed to the LC50 value of the commercial Bacillus thuringiensis (Bt) spray, Biobit®. The percentage of insecticidal activity (IA%) on 2nd-instar Biobit–exposed larvae was approximately the predicted 50 % mortality for all species except S. exigua. With all 4th instar Biobit–exposed larvae, mortality was not significantly different from that of unexposed larvae. Unexposed insects had a significantly higher PO activity in pre–pupae and pupae than early–instar larvae and adults, whereas PO activity was higher in adult females than in males. Correlation analysis between IA% and PO activity revealed significant r–values (p < 0.01) in 2nd instar H. virescens (r = 0.979) and P. interpunctella (r = 0.930). Second instar Biobit–exposed P. interpunctella had 10 times more PO activity than unexposed larvae. Similarly, the amount of total protein was lower in 4th instar Biobit–exposed H. virescens and higher in S. exigua. Therefore, the results indicated a relationship between Biobit susceptibility and PO activity in some cases. This information may be useful if the Biobit application period is timed for a developmental stage with low PO activity. However, more studies are needed to determine the correlation of each insect with a particular bioinsecticide

    Magnetic Nanoparticles of Chitosan for Targeted Delivery System of Plasmids to the Lungs

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    One of the major problems of gene therapy is the efficient, specific, and targeted delivery as well as the safety of the materials used in such systems. The specific targeted delivery of genes to the lung offers the possibility to treat a variety of specific diseases. We developed chitosan nanoparticles with the plasmid pCEM-Luc, which contains a promoter activated by magnetic field. Nanoparticles of 200–250 nm obtained by ionic gelation with a 99% retention rate were transfected in B16F10 cells and in vivo in the lungs of Balb/c mice by intratracheal administration. We observed that an external magnetic field increased the expression of the luciferase reporter gene in B16F10 cells transfected with magnetic nanoparticles and inhomogenized lungs of mice which determined differences in levels of expression between different regions of the lungs (apical or distal and left or right). The highest levels of luciferase activity were observed in the apical left region. The magnetic nanoparticles prove an efficient delivery system to in vitro transfection of cells and lung tissue

    Influencia de los campos electromágneticos en la expresión génica

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    Debido a la creciente utilización de la electricidad en la vida cotidiana, el ser humano está cada vez más expuesto a los campos electromagnéticos (CEM) que son generados por diversos aparatos, líneas de conducción y sub-estaciones eléctricas. Desde hace algunos años, ha surgido el interés sobre los efectos de estos campos en los sistemas biológicos. Se ha hecho énfasis en que los CEM son potencialmente capaces de afectar a nivel de síntesis de ADN, ARN y proteínas, además de la proliferación celular, y más recientemente se ha visto, que se puede alterar la expresión génica. Sin embargo, se han encontrado resultados variables, por lo que, hasta el momento, no se puede dar una conclusión definitiva sobre los efectos de este factor físico a los niveles antes mencionados. En este artículo, se presenta información general acerca del efecto biológico de los CEM, en particular en la expresión génica, incorporando además los últimos hallazgos al respecto que hemos obtenido en nuestro laboratorio. No se pretende una revisión exhaustiva del tema, sino más bien mostrar evidencias que indican que la expresión de diversos genes puede ser modificada por la radiación electromagnética, especialmente por la de frecuencia extremadamente baja (CEM), y que es ahora muy común en ciudades industrializadas

    The novel immunomodulator IMMUNEPOTENT CRP combined with chemotherapy agent increased the rate of immunogenic cell death and prevented melanoma growth

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    Abstract. Immunogenic cell death is a cell death modality that stimulates the immune system to combat cancer cells. IMMUNEPOTENT CRP (ICRP) is a mixture of substances of low molecular weight obtained from bovine spleens that exhibits in vitro cytotoxic activity on different tumor cell lines and modulates the immune response in vivo. The aim of the present study was to determine whether the cytotoxic effect of ICRP and its combination with oxaliplatin (OXP) on murine melanoma B16F10 cells was due to immunogenic cell death. The cytotoxic assay was performed using flow cytometry to detect Annexin V and propidium iodide staining, and calreticulin (CRT) exposure. Adenosine triphosphate, heat shock protein (HSP) 70, HSP90 and high mobility group box 1 (HMGB1) release were identified using bioluminescence, western blot and ELISA assays, respectively. The present in vitro study demonstrated that treatments with ICRP or OXP induced cell death in a time-dependent manner, but treatment with the combination of ICRP + OXP increased the cytotoxic effect following 24 h of treatment. CRT exposure and release of adenosine triphosphate (ATP), HSP70, HSP90 and HMGB1 were induced by treatment with ICRP, and the combination of ICRP + OXP increased the exposure and release of damage-associated molecular patterns (DAMPs), while OXP treatment only induced CRT exposure, ATP and HMGB1 release. The in vivo experiments demonstrated that administration of tumor-derived DAMP-rich cell lysates derived from B16F10 cells treated with ICRP and the combination of ICRP + OXP prevented melanoma growth; however, OXP treatment did not. These results suggested that IMMUNEPOTENT CRP may be used as an agent to increase the ability of antitumor drugs to induce immunogenic cell death and prevent the growth of melanoma

    Antitumor activity of colloidal silver on MCF-7 human breast cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Colloidal silver has been used as an antimicrobial and disinfectant agent. However, there is scarce information on its antitumor potential. The aim of this study was to determine if colloidal silver had cytotoxic effects on MCF-7 breast cancer cells and its mechanism of cell death.</p> <p>Methods</p> <p>MCF-7 breast cancer cells were treated with colloidal silver (ranged from 1.75 to 17.5 ng/mL) for 5 h at 37°C and 5% CO<sub>2 </sub>atmosphere. Cell Viability was evaluated by trypan blue exclusion method and the mechanism of cell death through detection of mono-oligonucleosomes using an ELISA kit and TUNEL assay. The production of NO, LDH, and Gpx, SOD, CAT, and Total antioxidant activities were evaluated by colorimetric assays.</p> <p>Results</p> <p>Colloidal silver had dose-dependent cytotoxic effect in MCF-7 breast cancer cells through induction of apoptosis, shown an LD<sub>50 </sub>(3.5 ng/mL) and LD<sub>100 </sub>(14 ng/mL) (*P < 0.05), significantly decreased LDH (*P < 0.05) and significantly increased SOD (*P < 0.05) activities. However, the NO production, and Gpx, CAT, and Total antioxidant activities were not affected in MCF-7 breast cancer cells. PBMC were not altered by colloidal silver.</p> <p>Conclusions</p> <p>The present results showed that colloidal silver might be a potential alternative agent for human breast cancer therapy.</p

    PhDAY 2020 -FOO (Facultad de Óptica y Optometría)

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    Por cuarto año consecutivo los doctorandos de la Facultad de Óptica y Optometría de la Universidad Complutense de Madrid cuentan con un congreso propio organizado por y para ellos, el 4º PhDAY- FOO. Se trata de un congreso gratuito abierto en la que estos jóvenes científicos podrán presentar sus investigaciones al resto de sus compañeros predoctorales y a toda la comunidad universitaria que quiera disfrutar de este evento. Apunta en tu agenda: el 15 de octubre de 2020. En esta ocasión será un Congreso On-line para evitar que la incertidumbre asociada a la pandemia Covid-19 pudiera condicionar su celebración
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