Untreated Control Cells (untreated + control_cell)

Distribution by Scientific Domains

Selected Abstracts

Pressure simulation of orthodontic force in osteoblasts: a pilot study

U. Baumert
Structured Abstract Authors , Baumert U, Golan I, Becker B, Hrala BP, Redlich M, Roos HA, Reichenberg E, Palmon A, Mig D Objectives , To elucidate the RUNX2 gene expression induction in human osteoblasts after mechanical loading. Design , Using a stringent pulse-chase protocol human osteoblasts were exposed to centrifugal pressure force for 30 and 90 min. Untreated control cells were processed in parallel. Before, and at defined times after centrifugation, total RNA was isolated. RUNX2 gene expression was measured using real-time quantitative reverse transcriptase polymerase chain reaction. The stress/control ratio was used to illustrate possible stimulatory or diminishing effects of force application. Results , Immediately after 30 min of force application the RUNX2 gene expression was induced by a factor of 1.7 0.14 as compared with the negative control. This induction decreased rapidly and reached its pre-load levels within 30 min. Longer force applications (up to 90 min) did not change the RUNX2 gene expression. Conclusion , In mature osteoblasts centrifugal pressure force stimulates RUNX2 gene expression within a narrow time frame: loading of mature cells results in a temporary increase of RUNX2 expression and a fast downregulation back to its pre-load expression level. With this pilot study the gene expression behavior after mechanical stimuli could be determined with a simple laboratory setup. [source]

Selectivity of N -aroyl- N,-arylthioureas towards 2-(1,3-dioxo-1H -inden-2(3H)-ylidene)malononitrile.

2- d][, 3]- thiazepin-2(6H)-ylidene)-4-arylamides of antitumor, New synthesis of (Z)- N -((E)-4-amino-1-aryl-5-cyano-6-oxo-1H -indeno[, antioxidant activities
The reaction between N -aroyl- N,-arylthioureas with 2-(1,3-dioxoindan-2-ylidene)malononitrile furnished indeno[1,2- d][1,3]thiazepines in 70,85% yields. The mechanism of the products' formation is discussed. Some of the products showed effective antitumor and antioxidant activities. The results revealed that compound indenothiazepine derivative showed a high inhibition of the cell growth of Hep-G2 cells is compared with the growth of untreated control cells, as concluded from their low IC50 value 21.73 ,M. On the other hand, two indenothiazepine derivatives have an effective antioxidant activity with SC50 values of 62.5 mM and 87.4 mM, respectively. J. Heterocyclic Chem., (2010). [source]

Evaluation of the Effect of Ethanol's Toxic Metabolite Acetaldehyde on the Gastrointestinal Oligopeptide Transporter, PEPT1: In Vitro and in Vivo Studies

ALCOHOLISM, Issue 1 2008
Scott J. Fisher
Background:, The effects of alcohol consumption and its subsequent metabolism on drug transport, absorption and pharmacokinetics are poorly understood. This study examines the effects of the ethanol metabolite, acetaldehyde, on the clinically relevant drug transporter, PEPT1. The metabolism of ethanol and the following acetaldehyde formation is thought to modulate the uptake capacity of PEPT1 within the gastrointestinal tract for a variety of clinically important peptidomimetic drug compounds. Methods:, Glycylsarcosine ([3H]-GlySar), a nonhydrolysable PEPT1 specific substrate was used in our studies. In vitro uptake studies were performed in the Caco-2 and Chinese hamster ovary (CHO)-hPEPT1 cell models, measuring cellular uptake of labeled compound against increasing levels of unlabeled compound in the presence of acetaldehyde. In vivo absorption of [3H]-GlySar was measured in male Sprague,Dawley rats that were treated with oral dose of ethanol/disulfiram (5 g/kg / 100 mg/kg) for 6 days. These results were compared to control rats treated with saline, ethanol alone or disulfiram alone. Results:, In vitro uptake of [3H]-GlySar in CHO-hPEPT1 cells treated with 1 mM acetaldehyde was significantly decreased (p < 0.05) as compared to untreated controls. The uptake of [3H]-GlySar in Caco-2 cell monolayers treated with 1 mM acetaldehyde was also significantly decreased as compared to the untreated control cells. In vivo absorption of [3H]-GlySar in ethanol treated rats, as measured by AUC0,12 hours were decreased by approximately 50% versus the control rat group. Conclusion:, The effects of acetaldehyde due to consumption of ethanol on the uptake and bioavailability of therapeutic drug compounds transported by the PEPT1 oligopeptide transporter have not been documented. In the present studies, we demonstrate that acetaldehyde significantly modulates PEPT1 function and, thereby, affects drug bioavailability. To our best knowledge, this is the first report on the effects of an ethanol metabolite on substrate absorption in the gastrointestinal tract, rather than interactions in the liver, which is an under-represented area of research in alcohol pathophysiology. [source]

Effects of ecdysteroids on Chlorella vulgaris

Andrzej Bajguz
The effects of three ecdysteroids, 20-hydroxyecdysone (20E), 2-deoxy-20-hydroxyecdysone (2d20E) and 20-hydroxyecdysone 22-acetate (20E22Ac), on growth and the levels of cellular components in Chlorella vulgaris Beijerinck (Trebouxiophyceae) are reported and compared with data previously reported for ecdysone (E; Bajguz A and Koronka A, Plant Physiol Biochem 39: 707,715, 2001). All three 20-hydroxyecdysteroids stimulate growth of C. vulgaris cells over a wide concentration range (10,16 to 10,7 M). Optimal stimulation is observed at 10,9 M with each ecdysteroid. High concentrations (>10,6 M) are cytotoxic. The potency ranking of the ecdysteroids is 20E > 20E22Ac > 2d20E > E. Levels per cell of DNA, RNA, protein, sugars, organic and inorganic phosphorus, chlorophylls a and b and phaeophytins a and b are all stimulated by ecdysteroid treatment when compared with the untreated control cells. Possible modes of action of ecdysteroids on C. vulgaris cells are discussed. [source]

Thieno[2,3- d]pyrimidines in the Synthesis of Antitumor and Antioxidant Agents

Ashraf A. Aly
Abstract Dimethyl acetylenedicarboxylate, ethyl propiolate, and E -dibenzoylethylene react with thienopyrimidines (cyclo-pentyl, -hexyl, and -heptyl) derivatives to form thiazolo[3,2- a]thieno-[2,3- d]pyrimidin-2-ylidene) acetates, thieno[2,3- d]pyrimidin-2-ylthioacrylates, and thieno[2,,3,:4,5]pyrimido[2,1- b][1,3]thiazin-6-ones, respectively. Reactions proceed via cyclization and thio-addition processes. Some derivatives of thienopyrimidines showed high inhibition of Hep-G2 cell growth compared with the growth of untreated control cells. However, the fused heptyl of thienopyrimidothiazines indicates a promising specific antitumor agent against Hep-G2 cells with IC50 < 20 ,M. [source]

Cortisol and IGF-1 synergistically up-regulate taurine transport by the rat skeletal muscle cell line, L6

BIOFACTORS, Issue 1-4 2004
Sung-Hee Park
Abstract This study was undertaken to evaluate effects of exercise-induced hormones, cortisol, IGF-1, and ,-endorphin, on the regulation of taurine transport activity in rat skeletal myoblasts, L6 cells. Challenge of L6 cells with cortisol (100 nM) for 24 hrs resulted in a 165% increase in taurine transport activity, 220% increase in Vmax of the taurine transporter, and 55% increase in taurine transporter/ ,-actin mRNA level compared with untreated control cells. Neither IGF-1 (1,100 nM) nor ,-endorphin (1,20 nM), added in the incubation medium separately for 24 hrs, affected taurine uptake by L6 cells. However, when cells were co-treated with IGF-1 (10 nM) plus cortisol (100,nM), taurine transport activity (37% increase, p < 0.05), Vmax of the transporter (54%, p < 0.05), and taurine transporter/ ,-actin mRNA level were further increased compared to the value for cells treated with cortisol alone. These results suggest that taurine transport by skeletal muscle cells appear to be synergistically up-regulated during a prolonged exercise via elevated levels of cortisol and IGF-1 in muscle. [source]

2134: Arachnoid cell changes following elevated pressure and oxidative stress: new implications for optic nerve degeneration

Purpose The study of meningothelial cells (MCs) and their connection to optic nerve function. MCs line the arachnoid layer of the meninges and form a barrier between the CSF and the blood circulation. A previous study revealed a significantly increased proliferation of MCs in the arachnoid surrounding the optic nerve glaucoma patients. Methods To explore a possible role of these cells in the pathogenesis of diseases of the optic nerve, we studied the effect of elevated hydrostatic pressure and oxidative stress on MCs using rotenone to inhibit mitochondrial function and compared them to untreated control cells. Cell viability and proliferation were measured using a MTS-based assay. As a measure of barrier function, we assessed the endocytotic activity of MCs by fluorescence and confocal microscopy following fluorescent-latex bead uptake. Results Exposure of MCs to elevated hydrostatic pressure caused significant cellular proliferation and a dramatic decrease in endocytotic activity. Furthermore, mild oxidative stress severely inhibited endocytosis, thus negatively impacting MC barrier function. Conclusion MCs surround the optic nerve, thereby shielding it from but also conditioning the microenvironment of this sensitive area. As elevated pressure and oxidative stress occur in patients with increased intracranial pressure who have papilledema and probably in some cases of normal-tension glaucoma, these phenomena may impact the function of MCs and thus, contribute to the loss of retinal ganglion cells in the course of these and, perhaps, other optic nerve diseases. [source]