Now showing items 1-8 of 8

Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis

Thomas, Christan M.; Wood, Robert C.; Wyatt, Jarrett E.; Pendleton, Morgan H.; Torrenegra, Ruben D.; Rodriguez, Oscar E.; Harirforoosh, Sam (2012-06)

Over 4000 flavonoids have been identified so far and among these, many are known to have antitumor activities. The basis of the relationships between chemical structures, type and position of substituent groups and the ...
Chemical and Biological Activity of Leaf Extracts of Chromolaena leivensis

Torrenegra G., Ruben D.; Rodríguez A., Oscar E. (2011)

The flavonoids 3,5-dihydroxy-7-methoxy-flavanone, 3,5-dihydroxy-7-methoxyflavone and 3,5,7-trihydroxy-6-methoxyflavone were isolated from the leaves of C. leivensis. Preliminary observations in K562 cells (human erythroleukemia) ...
Combretastatin A-4 induces p53 mitochondrial-relocalisation independent-apoptosis in non-small lung cancer cells

Méndez Callejas, Gina Marcela; Leone, Stefano; Tanzarella, Caterina; Antoccia, Antonio (2014)

CombretastatinA-4(CA-4)isoneofthemosteffectiveagentsusedinchemotherapy.Nevertheless,thecontributionofp53and Bim proteins in the CA-4-induced apoptosis in non-small lung cancer cells (NSCLC) remains unresolved, speciﬁcally ...
La comunidad fitoplanctónica en el evento de surgencia frente al mar caribe centro colombiano

Franco Herrera, Andrés; Torres Sierra, Eduardo Andrés (Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2007, 2007-01)

Con el objetivo de evaluar la estructura de la comunidad fitoplanctónica bajo la condiciones de surgencia y no surgencia en la costa central del Caribe colombiano y establecer su condición frente a este tipo ...
Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical

Ortiz Trujillo, Bibiana; Ospino, Benjamín; Trujillo, Miosotis (Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2007, 2007-07)

This research determined the possibility to change the hydroxyethyl starch (HES), conventional crioprotector, for two sorts of mandioca starches made by national industry. The study verified the influence of the mandioca ...
Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro

Urrego, R.; Bernal Uloa, S. M.; Chavarría, N. A.; Herrera-Puerta, E.; Lucas-Hahn, A.; Herrmann, D.; Winkler, S.; Pache, D.; Niemann, H.; Rodriguez-Osorio, N. (2017)

Bovine embryos produced in vivo and in vitro differ with respect to molecular profiles, including epigenetic marks and gene expression profiles. This study investigated the CpG methylation status in bovine testis satellite ...
Simulación de rutas de alteración de células de cuello uterino desde el estado normal hasta lesión intraepitelial de bajo grado

Rodríguez, Javier; Prieto, Signed; Melo, Martha; Domínguez, Darío; Cardona, Diana; Correa, Catalina; López, Fredy; Rodríguez, Ligia Victoria (Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2014, 2014-01)

A mathematical diagnosis of cells from cervicovaginal cytology was previously developed establishing objective and reproducible characterizations for different stages of cellular disturbance from normality to carcinoma. ...
Viroides: El otro tipo de fitopatógenos

Suárez Padrón, Isidro Elias; Jaraba Navas, Juán de Dios (Bogotá : Universidad de Ciencias Aplicadas y Ambientales, 2004, 2004-07)

Los viroides son cadenas simples circulares de ARN que tienen la capacidad de producir efectos patogénicos en las plantas. El primer viroide fue descubierto como tal en 1971 y desde entonces se han reportado algo más de ...

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Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis
...
Thomas, Christan M. | 2012-06

Over 4000 flavonoids have been identified so far and among these, many are known to have antitumor activities. The basis of the relationships between chemical structures, type and position of substituent groups and the effects these compounds exert specifically on cancer cells are not completely elucidated. Here we report the differential cytotoxic effects of two flavone isomers on human cancer cells from breast (MCF7, SK-BR-3), colon (Caco-2, HCT116), pancreas (MIA PaCa, Panc 28), and prostate (PC3, LNCaP) that vary in differentiation status and tumorigenic potential. These flavones are derived from plants of the family Asteraceae, genera Gnaphalium and Achyrocline reputed to have anti-cancer properties. Our studies indicate that 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays potent activity against more differentiated carcinomas of the colon (Caco-2), and pancreas (Panc28), whereas 3,5-dihydroxy6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) cytototoxic action is observed on poorly differentiated carcinomas of the colon (HCT116), pancreas (Mia PaCa), and breast (SK-BR3). Both flavones induced cell death (.50%) as proven by MTT cell viability assay in these cancer cell lines, all of which are regarded as highly tumorigenic. At the concentrations studied (5–80 mM), neither flavone demonstrated activity against the less tumorigenic cell lines, breast cancer MCF-7 cells, androgen-responsive LNCaP human prostate cancer line, and androgen-unresponsive PC3 prostate cancer cells. 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays activity against more differentiated carcinomas of the colon and pancreas, but minimal cytotoxicity on poorly differentiated carcinomas of these organs. On the contrary, 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) is highly cytotoxic to poorly differentiated carcinomas of the colon, pancreas, and breast with minimal activity against more differentiated carcinomas of the same organs. These differential effects suggest activation of distinct apoptotic pathways. In conclusion, the specific chemical properties of these two flavone isomers dictate mechanistic properties which may be relevant when evaluating biological responses to flavones.

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Chemical and Biological Activity of Leaf Extracts of Chromolaena leivensis
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Torrenegra G., Ruben D. | 2011

The flavonoids 3,5-dihydroxy-7-methoxy-flavanone, 3,5-dihydroxy-7-methoxyflavone and 3,5,7-trihydroxy-6-methoxyflavone were isolated from the leaves of C. leivensis. Preliminary observations in K562 cells (human erythroleukemia) using the trypan blue test, showed a 90% viability at a concentration of 100 µg/mL; however, further testing of the flavonoids at concentrations of 25, 50 and 100 µg/mL showed toxicity affecting the morphology of human erythroleukemia cells (K562) and human melanoma cells (A375). Induction of apoptosis was produced by 3.5-dihydroxy-7-methoxyflavone at 72 hours after treatment with arrest in the G2 / M phase of the cell cycle. The A375 cells treated with 50 µg/mL of 3.5-dihydroxy-7-methoxy-flavanone for 24, 48 and 72 hours, display effects on the behavior of the cell cycle. The flavonoid 3,5-dihydroxy-7-methoxyflavone has activity on the mitochondrial membrane at concentrations of 25, 50 and 100 µg/mL, at time intervals of 8 to 12 hours. The flavonoids 3,5-dihydroxy-7-methoxy-flavanone and 3,5-dihydroxy-7-methoxyflavone at a concentration of 25 µg/mL increased the expression of costimulatory molecules corresponding to the phenotype presented by mature dendritic cells with differentiation markers CD40, CD83, CD86 and HLA-DR. The two flavonoids at concentrations between 0.39 and 100 µg/mL slightly increased the proliferation of peripheral blood mononuclear cells in the presence and in the absence of phytohemagglutinin. These flavonoids at concentrations of 50 and 100 µg/mL slightly increased the proliferation of fibroblasts.

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Combretastatin A-4 induces p53 mitochondrial-relocalisation independent-apoptosis in non-small lung cancer cells
...
Méndez Callejas, Gina Marcela | 2014

CombretastatinA-4(CA-4)isoneofthemosteffectiveagentsusedinchemotherapy.Nevertheless,thecontributionofp53and Bim proteins in the CA-4-induced apoptosis in non-small lung cancer cells (NSCLC) remains unresolved, speciﬁcally on involving of p53 in the mitochondrial pathway activation by a transcription-independent mechanism. In this context, the p53null H1299 and wt-p53 H460 NSCLC cells, in the absence and presence of piﬁthrin-m (PFTm), an inhibitor of p53 mitochondrial-translocation, were treated with CA-4 and different cellular endpoints were analysed. In contrast to previous observationsinH460cells,CA-4failedintheactivationofanapoptoticresponseinH1299cells,thusindicatinganinvolvement of p53 in the cell death induced by the drug. We found that CA-4 led to p53 cellular re-localisation in H460 cells; in particular, p53 was released from the microtubular network and accumulated at mitochondria where it interacts with Bim protein and other proteins of the Bcl-2 (B-cell leukaemia-2) family, leading to cytochrome c release, alteration in the mitochondrial membrane polarisation, cell cycle arrest at the G2/M-phase, and cell death. Interestingly, the cytosolic and the mitochondrial accumulation of protein Bim was strictly dependent on p53 status. The extent of cell death was not reduced in H460 after combinedtreatmentofPFTmwithCA-4.Overall,thedatasupportamodelofCA-4-inducedapoptosisinNSCLC,forwhichthe expression of p53 protein is essential, but its mitochondrial function, linked to p53-transcription independent apoptosis pathway, is negligible.

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La comunidad fitoplanctónica en el evento de surgencia frente al mar caribe centro colombiano
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Franco Herrera, Andrés | 2007-01

Con el objetivo de evaluar la estructura de la comunidad fitoplanctónica bajo la condiciones de surgencia y no surgencia en la costa central del Caribe colombiano y establecer su condición frente a este tipo de eventos oceanográficos a escala regional, se adelantaron cua-tro muestreos siguiendo el método Eureliano, entre los meses de julio a septiembre de 2006 en la columna de agua (0-50m), dos en condiciones de surgencia y los restantes en no surgencia. Se evaluó la composición, la abundancia, la dominancia y la diversidad fitoplanc-tónica a partir de muestras obtenidas con botella Van Dorn y arrastres horizontales. Se encontró que el grupo dominante fueron las diatomeas, específicamente las especies de los géneros Skeletonema, Chaetoceros, Coscinodiscus y Thalassionema, con densidades supe-riores a 50 cel/L. No se detectaron claras diferencias en la composición específica fitoplanctónica bajo las dos condiciones oceanográficas, pero sí mayores densidades de células en ausencia de surgencia. Ecológicamente, el fitoplancton se caracterizó por una alta riqueza de especies y una baja dominancia, lo que se reflejó en una alta diversidad. Desde esta perspectiva, el fitoplancton, en el sistema de surgencia analizado, se constituye en una comunidad análoga a aquellas que se encuentran en las grandes surgencias permanentes de borde occidental de los continentes.

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Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical
...
Ortiz Trujillo, Bibiana | 2007-07

This research determined the possibility to change the hydroxyethyl starch (HES), conventional crioprotector, for two sorts of mandioca starches made by national industry. The study verified the influence of the mandioca starches on the hidrogenions amount in blood and confirmed the estability of starches in umbilical cord blood envelop and established its molecular stability inside a medium with amylases enzymes and mononuclear cells such as the umbilical cordon blood. The mononuclear cells viability six months after being criopreservated with each starch at –80ºC, using HES as a reference or standard, was also assessed. Results showed that the umbilical cord blood, outside the organism for 30 minutes is more affected by the mandioca starches than by HES. In spite of the similar structure of the mandioca starch and HES, the latter one is more resistant in the blood environment to the enzymatic attack of amylases because of its modified structure, therefore it is more resistance to withstand the blood conditions. It was corroborated that HES was able to keep the mononuclear cell viability over 70%, but mandioca starches did not, because of their influence on the pH which became lethal to cells. It was concluded, that the amilopectine of mandioca starches with some modifications in its molecular structure such as hydroxyethylation could work as a crioprotector for mononuclear blood cells, provided that the pH is controlled.

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Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro
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Urrego, R. | 2017

Bovine embryos produced in vivo and in vitro differ with respect to molecular profiles, including epigenetic marks and gene expression profiles. This study investigated the CpG methylation status in bovine testis satellite I (BTS) and Bos taurus alpha satellite I (BTαS) DNA sequences, and concomitantly the relative abundance of transcripts, critically involved in DNA methylation (DNMT1 and DNMT3A), growth and development (IGF2R) and pluripotency (POU5F1) in Bos indicus embryos produced in vitro or in vivo. Results revealed that methylation of BTS were higher (P < 0.05) in embryos produced in vitro compared with their in vivo produced counterparts, while the methylation status of BTαS was similar in both groups. There were no significant differences in transcript abundance for DNMT3A, IGF2R and POU5F1 between blastocysts produced in vivo and in vitro. However, a significantly lower amount of DNMT1 transcripts was found in the in vitro cultured embryos (P < 0.05) compared with their in vivo derived counterparts. In conclusion, this study reported only minor changes in the expression of developmentally important genes and satellite DNA methylation related to the in vitro embryo production system.

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Simulación de rutas de alteración de células de cuello uterino desde el estado normal hasta lesión intraepitelial de bajo grado
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Rodríguez, Javier | 2014-01

A mathematical diagnosis of cells from cervicovaginal cytology was previously developed establishing objective and reproducible characterizations for different stages of cellular disturbance from normality to carcinoma. In this paper we start from this methodology to establish possible routes of preneoplastic alteration from normal to L-SIL. Ten digital images of squamous cells of cervix uterine with normal diagnosis were studied. The images were analyzed through a software with which fractal dimension of defined mathematical objects was calculated. Fractal variability and Cellular Intrinsic Mathematical Harmony (IMH) values were calculated for each sample. From these values, simulations of disturbances paths of each normal cell towards to L-SIL cell were realized, doing three possible variations of spaces of cellular occupation in Box-counting space. A possible disturbance path towards to L-SIL state for each normal cell was established. Each path is defined by three variation possibilities of spaces of occupation of defined objects. Each possibility can exhibit mathematical characteristics of intermediate states of disturbance. Fractal dimension values of the three defined objects in normal cells: cytoplasm, nucleus and totality were between 1.0512 y 1.9944. Variability and IMH values were between 0 and 6. A fractal organization of cervix cellular structure was evidenced allowing to establish simulation of disturbance. This finding can represent a useful tool in clinical practice.

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Viroides: El otro tipo de fitopatógenos
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Suárez Padrón, Isidro Elias | 2004-07

Los viroides son cadenas simples circulares de ARN que tienen la capacidad de producir efectos patogénicos en las plantas. El primer viroide fue descubierto como tal en 1971 y desde entonces se han reportado algo más de 30 especies diferentes, las cuales se han clasificado en dos grandes familias: la Pospiviroidae y la Avsunviroidae. Debido a la ausencia de capacidad codificadora de proteínas, los viroides secuestran productos de la célula que infectan para poder replicarse mediante la síntesis de nuevas moléculas siguiendo diferentes mecanismos de acuerdo al tipo de viroide. Los síntomas producidos por las infecciones viroidales son diversos y pueden ir desde las infecciones asintomáticas hasta la muerte total de la planta. La transmisión de los viroides puede ocurrir fácilmente a través de semillas, de material vegetativo, de herramientas e incluso de granos de polen, mientras que la única m ed id a d isp o n ib le para e v ita r la diseminación de las enfermedades es la erradicación de plantas infectadas. Aunque la siembra de material sano permanece como la medida de control mas efectiva, en la actualidad se trabaja con técnicas biotecnológicas para crear materiales resistentes o producir plantas sanas a partir de material infectado.

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Browsing by Subject "Células"

Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis ﻿

Chemical and Biological Activity of Leaf Extracts of Chromolaena leivensis ﻿

Combretastatin A-4 induces p53 mitochondrial-relocalisation independent-apoptosis in non-small lung cancer cells ﻿

La comunidad fitoplanctónica en el evento de surgencia frente al mar caribe centro colombiano ﻿

Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical ﻿

Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro ﻿

Simulación de rutas de alteración de células de cuello uterino desde el estado normal hasta lesión intraepitelial de bajo grado ﻿

Viroides: El otro tipo de fitopatógenos ﻿

Envíos recientes

Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis

Chemical and Biological Activity of Leaf Extracts of Chromolaena leivensis

Combretastatin A-4 induces p53 mitochondrial-relocalisation independent-apoptosis in non-small lung cancer cells

La comunidad fitoplanctónica en el evento de surgencia frente al mar caribe centro colombiano

Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical

Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro

Simulación de rutas de alteración de células de cuello uterino desde el estado normal hasta lesión intraepitelial de bajo grado

Viroides: El otro tipo de fitopatógenos

Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis

Chemical and Biological Activity of Leaf Extracts of Chromolaena leivensis

Combretastatin A-4 induces p53 mitochondrial-relocalisation independent-apoptosis in non-small lung cancer cells

La comunidad fitoplanctónica en el evento de surgencia frente al mar caribe centro colombiano

Evaluación de la actividad crioprotectora de dos almidones de yuca sobre células mononucleadas de sangre de cordón umbilical

Satellite DNA methylation status and expression of selected genes in Bos indicus blastocysts produced in vivo and in vitro

Simulación de rutas de alteración de células de cuello uterino desde el estado normal hasta lesión intraepitelial de bajo grado

Viroides: El otro tipo de fitopatógenos