BackgroundDuring the last few years it has been shown in several laboratories that Celecoxib (Cx), a non-steroidal anti-inflammatory agent (NSAID) normally used for pain and arthritis, mediates antitumor and antiangiogenic effects. However, the effects of this drug on a tumor cell line resistant to chemotherapeutical drugs used in cancer have not been described.Herein we evaluate the angiogenic and antitumor effects of Cx in the development of a drug-resistant mammary adenocarcinoma tumor (TA3-MTXR).ResultsCx reduces angiogenesis in the chick embryonic chorioallantoic membrane assay (CAM), inhibits the growth and microvascular density of the murine TA3-MTXR tumor, reduces microvascular density of tumor metastases, promotes apoptosis and reduces vascular endothelial growth factor (VEGF) production and cell proliferation in the tumor.ConclusionThe antiangiogenic and antitumor Cx effects correlate with its activity on other tumor cell lines, suggesting that Prostaglandins (PGs) and VEGF production are involved. These results open the possibility of using Celecoxib combined with other experimental therapies, ideally aiming to get synergic effects.

In this work, we have completed a study of the development of the ovoviviparous lizard Liolaemus tenuis tenuis. Ovoviviparity in this lizard is a condition in which eggs are retained within the reproductive duct for about 60 days. During this period the phases of segmentation, gastrulation, neurulation, presomitic, and somitic embryos transpire. During the months of December and January the eggs are laid, and at this time the embryos are comparable to stage 27 Liolaemus gravenhorsti lizard embryos, or to stage 29 Calotes versicolor lizard embryos. Differentiation of the facial region occurs between Days 12 and 42 after egg laying. Limbs develop rapidly between the 8th and 23rd days. By 53 days the appendicular skeleton is completely formed. After 36 days the mesonephros begins to degenerate, and its function is gradually taken over by the developing metanephros. Newborn lizards do not possess an egg caruncle. During the period up to hatching, there is a great increase of liquid within the egg, presumably amniotic fluid. Cracks develop in the leathery shell shortly before hatching and are, perhaps, the first sign of the onset of hatching. Increase of liquid in the egg during postlaying development accounts for its increase in weight and change in shape. Weight of the embryo at hatching does not exceed 32% of the total weight of the egg.

(DH, and AV); d Naturalis S.A., Santiago, Chile (MCB, and MF) *Corresponding author: dnhaim@miuandes.cl RESUMEN La esterificación de ácido oleico en policosanoles aumenta su biodisponibilidad y el efecto hipocolesterolémico en ratasLos Policosanoles están formados por una mezcla de alcoholes alifáticos de cadena larga y se obtienen de las ceras de la caña de azúcar. Más de cincuenta estudios indican que los policosanoles reducen el colesterol sérico, mientras que otros no logran reproducir este efecto. El objetivo de esta investigación fue evaluar la biodisponibilidad de policosanoles esterificados y no esterificados (NEP), en relación con sus efectos hipocolesterolémicos. Para ello, a ratas Sprague Dawley se les administró una dosis oral diaria de 100 mg kg -1 de NEP, 117 mg kg -1 de policosanoles esterificados con ácido butírico (BAEP), ó 164 mg kg -1 de policosanoles esterificados con ácido oleico (OAEP). La absorción de los policosanoles se evaluó en el plasma entre 0 y 3 horas después de la ingestión. Para evaluar los cambios en el colesterol total, colesterol-LDL, colesterol-HDL y triglicéridos en el plasma y en la fosforilación de la hígado 3-hidroxi-3-metilglutaril coenzima A reductasa (HMG-CoA red), la ingesta de las ratas fue suplementada con policosanoles no esterificados o esterificados durante 5 semanas. Los resultados indicaron que la absorción de los policosanoles fue significativamente mayor en las ratas tratadas con los OAEP que en las sometidas a los NEP o las que se les administró BAEP. Los OAEP redujeron significativamente el colesterol plasmático total y el colesterol-LDL de las ratas, además de aumentar 5.6 veces (P < 0,05) sobre los valores control, en el contenido hepático de la HMG-CoA fosforilada red. En conclusión, la esterificación de policosanoles con ácido oleico aumenta la biodisponibilidad de los policosanoles, y mejora significativamente el perfil de lípidos séricos en ratas normocolesterolémicos en asociación con la inactivación de la colesterogénesis control HMG-CoA red. PALABRAS-CLAVE: Absorción de Policosanoles -Biodisponibilidad -Efecto reductor de colesterol -Octacosanol -Policosanol -Triacontanol -Ratas. SUMMARY The oleic acid esterification of policosanol increases its bioavailability and hypocholesterolemic action in ratsPolicosanol comprises a mixture of long-chain aliphatic alcohols from sugarcane wax. More than 50 studies indicate that policosanol decreases serum cholesterol, while others failed to reproduce this effect. The objective of this investigation was to assess the bioavailability of esterified policosanol and non-esterified policosanol (NEP), in relation to their hypocholesterolemic effects. Sprague Dawley rats were given a daily oral dose of 100 mg/kg of NEP, 117 mg kg -1 of butyric acid esterified policosanol (BAEP), or 164 mg kg -1 of oleic acid esterified policosanol (OAEP). Policosanol absorption was evaluated in plasma between 0 and 3 hours after ingestion. To assess changes in total cholesterol, LDL-cholesterol, HDLcholesterol and triacylglycerols in ...

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Using tartrate-resistant acid phosphatase (TRAP), we examined the cytodifferentiation of odontoclast cells in resorbing areas of dental tissues during the replacement of teeth in a polyphyodont lizard, Liolaemus gravenhorsti. We also report, by means of Lectin-HRP histochemistry, the distribution pattern of some specific sugar residues of TRAPase-positive cells. For detection of TRAPase activity, the azo dye-coupling technique was used. Lectin binding sites were demonstrated by means of specific HRP-lectins. The process of tooth resorption was divided into four stages: 1) preresorption-the wall of the dental pulp is covered with an odontoblast layer, and no TRAPpositive cells are in the dental pulp; 2) early resorption-TRAP-positive multinucleate odontoclasts are present on the dental wall, but the rest of the pulp surface is still covered with an odontoblast layer; 3) later resorption-the entire surface of the pulp chamber is lined with multinucleate odontoclasts; and 4) final resorption-the tooth has been totally resorbed. Odontoclasts are usually detached from the resorbed surface, and show signs of degeneration. Of the six lectins used, PNA, ECA, and UEA-1 bind to multinucleated but not mononuclear cells. All the remaining lectins, BS-1, RCA 120 , and LTA showed no binding to any cells of the teeth. The significance of saccharidic moieties such as acetyl-galactosamine, acetyl-glucosamine, and fucose sugar residues is difficult to ascertain. Perhaps these oligosaccharides might be borne on molecules associated with odontoclastic resorption or associated with multinucleation of odontoclasts after attachment to the dentine surface.