Search results for "Chloramphenicol"
showing 10 items of 23 documents
Sterol Regulatory Element-binding Protein-1c Is Responsible for Cholesterol Regulation of Ileal Bile Acid-binding Protein Gene in Vivo
2002
Ileal bile acid-binding protein (I-BABP) is a cytosolic protein that binds bile acid (BA) specifically. In the ileum, it is thought to be implied in their enterohepatic circulation. Because the fecal excretion of BA represents the main physiological way of elimination for cholesterol (CS), the I-BABP gene could have a major function in CS homeostasis. Therefore, the I-BABP gene expression might be controlled by CS. I-BABP mRNA levels were significatively increased when the human enterocyte-like CaCo-2 cells were CS-deprived and repressed when CS were added to the medium. A highly conserved sterol regularory element-like sequence (SRE) and a putative GC box were found in human I-BABP gene pr…
Chloramphenicol effects on adventitious root production by radish hypocotyls
1990
Abstract The excision of the root accelerates greatly the formation of adventitious roots in the hypocotyl of etiolated radish seedlings, but if the seedlings develop in CAP 1×10−4M, no adventitious root are induced after cutting. IAA either alone or associated with CAP, significantly increases the number of primordia in normal hypocotyls if given at the moment of cutting, while it has not stimulatory effect on the hypocotyls of seedlings grown in CAP. IAA has significant effect on both elongation and tickening of hypocotyl segments prepared from seedlings grown in CAP, and this could indicate a specific action of the inhibitor either on a particular process or on particular cells. The endo…
Nano-Silica Carriers Coated by Chloramphenicol: Synthesis, Characterization, and Grinding Trial as a Way to Improve the Release Profile
2022
Silica nanoparticles were applied as the carrier of chloramphenicol (2,2-dichloro-N-[(1R,2R)-1,3-dihydroxy-1-(4-nitrophenyl)propan-2-yl]acetamide), and were loaded in a 1% carbopol-based gel (poly(acrylic acid)), which allowed obtainment of an upgraded drug form. The samples of silica materials were obtained by means of modified Stöber synthesis, and their morphological properties were analyzed using Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) method, elemental analysis (EA), thermogravimetric analysis (TGA), analysis of the specific surface properties, X-ray diffraction study (XRD), scanning electron microscope (SEM), and dynamic light scattering (DLS) meth…
A novel SP-1 site in the human interleukin-1β promoter confers preferential transcriptional activity in keratinocytes
1996
To investigate the mechanisms of transcriptional activation of interleukin-1beta (IL-1beta) in non-monocytic cells, we constructed a series of reporter plasmids with the bacterial chloramphenicol acetyltransferase gene linked to various parts of the human IL-1beta promoter and performed transient transfection experiments. We identified a promoter segment that activates transcription most efficiently in keratinocytes. Electrophoretic mobility shift assays (EMSA) with a 43-mer oligonucleotide derived from the functionally identified cis-acting element revealed specific complexes. By competition analysis with transcription factor consensus sequence oligonucleotides and by immunosupershift, tra…
Ribosome-Targeting Antibiotics Impair T Cell Effector Function and Ameliorate Autoimmunity by Blocking Mitochondrial Protein Synthesis
2019
Summary While antibiotics are intended to specifically target bacteria, most are known to affect host cell physiology. In addition, some antibiotic classes are reported as immunosuppressive for reasons that remain unclear. Here, we show that Linezolid, a ribosomal-targeting antibiotic (RAbo), effectively blocked the course of a T cell-mediated autoimmune disease. Linezolid and other RAbos were strong inhibitors of T helper-17 cell effector function in vitro, showing that this effect was independent of their antibiotic activity. Perturbing mitochondrial translation in differentiating T cells, either with RAbos or through the inhibition of mitochondrial elongation factor G1 (mEF-G1) progressi…
Stress response in mesoangioblast stem cells
2006
Stem cells are presumed to survive various stresses, since they are recruited to areas of tissue damage and regeneration, where inflammatory cytokines and cytotoxic cells may result in severe cell injury. We explored the ability of mesoangioblasts to respond to different cell stresses such as heat, heavy metals and osmotic stress, by analyzing heat shock protein (HSP)70 synthesis as a stress indicator. We found that the A6 mesoangioblast stem cells constitutively synthesize HSP70 in a heat shock transcription factor (HSF)-independent way. However, A6 respond to heat shock and cadmium treatment by synthesizing HSP70 over the constitutive expression and this synthesis is HSF1 dependent. The e…
[Macrolides in the treatment of children with Mediterranean spotted fever].
2002
Till now there is not a gold standard therapy for Mediterranean spotted fever (MSF) in children. Standard treatment for MSF is the administration of tetracycline or chloramphenicol, however both these drugs can cause significant adverse effects in children (tetracyclines can cause staining of teeth, chloramphenicol severe hematological adverse events such as aplastic anemia, gray baby syndrome and hemolytic anemia in patients with the Mediterranean form of G6PD deficiency). We conducted two randomized clinical trials; the first compared clarithromycin versus chloramphenicol: mean time to defervescence was 36.7 +/- 18.1 h in the clarithromycin group and 47.1+/- 21.9 h in the chloramphenicol …
Comparative Study of Different Methods for the Prediction of Drug–Polymer Solubility
2015
In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid ana…
Binding of Tat Protein to TAR Region of Human Immunodeficiency Virus Type 1 Blocks TAR-Mediated Activation of (2′-5′)Oligoadenylate Synthetase
1990
The TAR sequence of the 5' leader of HIV-1 long terminal repeat-directed mRNA was found to be able to bind to and to activate double-stranded RNA-dependent (2'-5')A synthetase. Binding of TAR to the purified synthetase in vitro was abolished by addition of HIV-1 Tat protein, which binds to this sequence with a high affinity. Inhibition of TAR-mediated activation of (2'-5')A synthetase by Tat was prevented in the presence of the Zn2+ and Cd2+ chelators o-phenanthroline and penicillamine, which did not impair TAR-synthetase interaction. Transient expression assays of bacterial chloramphenicol acetyltransferase (CAT) gene in HeLa cells revealed that the levels of both CAT mRNA and CAT protein …
A Promising New Method to Estimate Drug-Polymer Solubility at Room Temperature
2016
The established methods to predict drug-polymer solubility at room temperature either rely on extrapolation over a long temperature range or are limited by the availability of a liquid analogue of the polymer. To overcome these issues, this work investigated a new methodology where the drug-polymer solubility is estimated from the solubility of the drug in a solution of the polymer at room temperature using the shake-flask method. Thus, the new polymer in solution method does not rely on temperature extrapolations and only requires the polymer and a solvent, in which the polymer is soluble, that does not affect the molecular structure of the drug and polymer relative to that in the solid st…