Search results for "acids"
showing 10 items of 3520 documents
Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent
2016
The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our sy…
Phenolic compounds and abscisic acid as potential markers for the floral origin of two Polish unifloral honeys
2012
The phenolic profiles of Polish honey samples from heather (Calluna vulgaris L.) and buckwheat (Fagopyrum esculentum L.) were determined. The phenolic components were isolated from honey samples using Amberlite-XAD-2 as a solid-phase extraction sorbent. For the determination of the composition of the honey extracts HPLC with photodiode array detector was applied. Identification and quantification of phenolics was performed by comparison of their retention times and UV spectra with those of standard solutions of pure reference substances and by using those references as external standards. From among 20 commercially available standards over 15 of them were identified as present in all analys…
Histone deacetylase inhibition modulates deoxyribonucleotide pools and enhances the antitumor effects of the ribonucleotide reductase inhibitor 3’-C-…
2011
Histone deacetylase (HDAC) inhibitors are a new class of epigenetic agents that were reported to enhance the cytotoxic effects of classical anticancer drugs through multiple mechanisms. However, which of the possible drug combinations would be the most effective and clinically useful are to be determined. We treated the HL60 and NB4 promyelocytic leukaemia cells with a combination of the ribonucleotide reductase (RR) inhibitor 3'-C-methyladenosine (3'-Me-Ado) and several hydroxamic acid-derived HDAC inhibitors, including two recently synthesized molecules, MC1864 and MC1879, and the reference compound trichostatin A (TSA). The results showed significant growth inhibitory and apoptotic syner…
SAHA induces apoptosis in hepatoma cells and synergistically interacts with the proteasome inhibitor Bortezomib.
2007
Histone deacetylase (HDAC) inhibitors represent a promising group of anticancer agents. This paper shows that the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) stimulated at 5-10 microM apoptosis in human hepatoma HepG2 and Huh6 cells, but was ineffective in primary human hepatocytes (PHH). In HepG2 cells SAHA induced the extrinsic apoptotic pathway, increasing the expression of both FasL and FasL receptor and causing the activation of caspase-8. Moreover, SAHA enhanced the level of Bim proteins, stimulated alternative splicing of the Bcl-X transcript with the expression of the proapoptotic Bcl-Xs isoform, induced degradation of Bid into the apoptotic factor t-Bid and dephosphorylat…
Holo-APP and G-protein-mediated signaling are required for sAPPa-induced activation of the Akt survival pathway
2014
International audience; Accumulating evidence indicates that loss of physiologic amyloid precursor protein (APP) function leads to reduced neuronal plasticity, diminished synaptic signaling and enhanced susceptibility of neurons to cellular stress during brain aging. Here we investigated the neuroprotective function of the soluble APP ectodomain sAPPa (soluble APPa), which is generated by cleavage of APP by a-secretase along the non-amyloidogenic pathway. Recombinant sAPPa protected primary hippocampal neurons and SH-SY5Y neuroblastoma cells from cell death induced by trophic factor deprivation. We show that this protective effect is abrogated in neurons from APP-knockout animals and APP-de…
Bortezomib: a new pro-apoptotic agent in cancer treatment.
2010
Bortezomib is a proteasome inhibitor. It targets the ubiquitin-proteasome pathway with subsequent inhibition of the degradation of proteins involved in cell cycle regulation and cancer cell survival. The best known molecular mechanism concerns the inhibition of IkappaB breakdown and the related stabilization of NFkappaB, thus preventing its translocation to the nucleus for the activation of downstream pathways. Bortezomib is the only drug in this class which has been approved for clinical use. It has shown an efficient antitumor effect in a phase III clinical trial (APEX) involving relapsed multiple myeloma patients. Response rate, time to progression and overall survival have been improved…
Sphingomyelin induces structural alteration in canine parvovirus capsid.
2007
One of the essential steps in canine parvovirus (CPV) infection, the release from endosomal vesicles, is dominated by interactions between the virus capsid and the endosomal membranes. In this study, the effect of sphingomyelin and phosphatidyl serine on canine parvovirus capsid and on the phospholipase A(2) (PLA(2)) activity of CPV VP1 unique N-terminus was analyzed. Accordingly, a significant (P< or =0.05) shift of tryptophan fluorescence emission peak was detected at pH 5.5 in the presence of sphingomyelin, whereas at pH 7.4 a similar but minor shift was observed. This effect may relate to the exposure of VP1 N-terminus in acidic pH as well as to interactions between sphingomyelin and CP…
Redistribution of CD95, DR4 and DR5 in rafts accounts for the synergistic toxicity of resveratrol and death receptor ligands in colon carcinoma cells.
2004
The natural phytoalexin resveratrol (3, 5, 4'-trihydroxystilbene) exhibits both chemopreventive and antitumor activities through a variety of mechanisms. We have shown previously that resveratrol-induced apoptosis of a human colon cancer cell line involved the redistribution of CD95 (Fas/Apo-1) into lipid rafts. Here, we show that, in colon cancer cells that resist to resveratrol-induced apoptosis, the polyphenol also induces a redistribution of death receptors into lipid rafts. This effect sensitizes these tumor cells to death receptor-mediated apoptosis. In resveratrol-treated cells, tumor necrosis factor (TNF), anti-CD95 antibodies and TNF-related apoptosis-inducing ligand (TRAIL) activa…
Erzeugung von Sarkomen durch Fremdkörper aus Polymethacrylaten und Zusätzen
1962
Es wird uber die cancerogene Wirkung von Plattchen aus verschiedenen Kunststoffen berichtet (s. Tabelle).
Ganglioside GD3 shedding by human malignant melanoma cells
1989
Gangliosides appear to be important target molecules for immunological effector mechanisms on neuro-ectodermal tumors. Therefore in vitro studies were performed to examine whether ganglioside GD3, which is highly expressed on the cell surface of cultured human melanoma cells, is being shed into the culture medium. Measurable quantities of gangliosides GM3 and in particular GD3 were shed by the melanoma cells we have tested as detected on thin-layer chromatograms (TLC) stained with orcinol. Ganglioside GD3 was also evidenced by immunostaining with anti-GD3 MAb and by ELISA. The concentration of GD3 in the supernatant of human melanoma cells depended on the ganglioside pattern of the cell lin…