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Inhalation Toxicity of Metal Particles and Vapors
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Barium and its salts are used extensively in the manufacture of various alloys, in paints, soap, paper, and rubber, and in the manufacture of ceramics and glass. Barium hydroxide is used in sugar refining. Barium fluorosilicate and carbonate have been used as insecticides and rodenticides. Barium sulfate, an insoluble compound, is used as a radiopaque material to aid in x-ray diagnosis.
Precipitation and Acid/Base Aqueous Reactions
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
For these equations, the combination of H+ and OH- must always produce only H2O; combining the unbalanced acid and base portions to form H(OH)2 is not valid; BaBr is not a correct formula. To balance the complete equation, first balance the acid to the base by matching the correct number of H+ ions to the correct number of base portions. Each formula of barium hydroxide contains two hydroxide ion base portions; each hydrobromic acid transfers only one H+ ion: two HBr are required for each Ba(OH)2, which then forms two H2O molecules. If this is performed correctly, the correct formula for the other product, BaBr2 in this example, will be confirmed.
Drug-induced acute upper airway obstruction
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
Michael Lippmann, Ganesan Murali
There have been several case reports describing spontaneous ignition and fire in the operating room after the use of sevoflurane due to a chemical reaction with carbon dioxide absorbers containing barium hydroxide. Considerable melting of the plastic components of the anaesthesia machine was noted (no fatalities occurred). This is a potential problem with all halogenated anaesthetics and attention should be given to the avoidance of strong alkaline absorbents when using these agents.72,73
Poly (ADP-ribose) polymerase inhibitors sensitize cancer cells to hypofractionated radiotherapy through altered selection of DNA double-strand break repair pathways
Published in International Journal of Radiation Biology, 2022
Yuji Seo, Keisuke Tamari, Yutaka Takahashi, Kazumasa Minami, Shotaro Tatekawa, Fumiaki Isohashi, Osamu Suzuki, Yuichi Akino, Kazuhiko Ogawa
HCT116 cells were incubated with or without PARPi (PJ34 5 μmol/L or olaparib 1 μmol/L) for 2 h, and then IR was delivered at 0 or 10 Gy. After 24-h incubation with or without the drug, demecolcine was added to each dish at a final concentration of 0.1 μg/mL. The cells were incubated for an additional 6 h, and then harvested with trypsinization. The cells were washed twice in PBS and fixed by dropwise addition of 1:4 acetic acid:methanol solution. The fixed cells were spread onto a slide in a dropwise fashion and air dried. The slides were treated in 0.2 N hydrochloric acid at room temperature for 30 min. After washing three times in distilled water, the slides were placed in 5% barium hydroxide at 60 °C for 1 min. The slides were treated again in 0.2 N hydrochloric acid for 2 min and then washed in distilled water for 2 min. Finally, the slides were incubated in 2× SSC at 60 °C for 45 min and washed in distilled water. The slides were stained with Hoechest 33432, mounted, and observed using a fluorescent microscope with ×100 objectives. More than 100 metaphase nuclei were analyzed, and dicentric chromosomes were manually counted.
Boswellic acids: privileged structures to develop lead compounds for anticancer drug discovery
Published in Expert Opinion on Drug Discovery, 2021
Hidayat Hussain, Iftikhar Ali, Daijie Wang, Faruck L. Hakkim, Bernhard Westermann, Luay Rashan, Ishtiaq Ahmed, Ivan R. Green
In 1932 Winterstein and Stein [40] (Scheme 2) reported on the first extraction and purification of natural BAs with preparative HPLC as the final purification step [60] and many natural product chemists are still using this very similar procedure today. The Winterstein and Stein protocol includes treating the whole extract with barium hydroxide (to form barium salts) followed by treatment with acetic anhydride in order to isolate the acetylated α- and β-isomers of the BAs. In 1998 Shao et al. [12] published another protocol for the extraction of BAs from frankincense. They extracted the raw frankincense with methanol to which was added a 2% KOH solution and followed this by extraction with EtOAc. The remaining aqueous solution was then neutralized with 2% HCI and again followed by extraction with EtOAc. The combined EtOAc extract from the second treatment which contains the free BAs was washed with water and dried over Na2SO4 to yield the BAs after removal of the EtOAc under reduced pressure. Beton et al. [48] further modified the procedure of Winterstein and Stein [40] and obtained better results (higher quantity and purity). In 2004 Bergmann [54] reported on a new ion exchange method in his PhD thesis using the ion exchanger IRA-900. The author claimed that this process is feasible both on a laboratory as well as on a larger scale.
The anti-depressant effects of a novel PDE4 inhibitor derived from resveratrol
Published in Pharmaceutical Biology, 2021
Yingcong Yu, Jinhui Wang, Xianfeng Huang
All the enzymatic activities of PDEs were assayed by using 3H- cyclic guanosine monophosphate (cGMP) or 3H-cAMP as the substrate. PDEs were firstly incubated with the reaction mixture of 50 mmol/L Tris-hydrogen chloride (HCl), pH 7.8, 10 mmol/L magnesium chloride (MgCl2) and 3H-cAMP or 3H-cGMP (40, 000 cpm/assay) at 24 °C for 30 min. Then, the reaction was terminated by addition of zinc sulfate and barium hydroxide. Activity of test compounds was assessed by measuring the amount of 3H-cGMP or 3H-cAMP resulting from enzyme cleavage. The reaction product 3H-AMP or 3H-GMP was precipitated by adding barium sulfate, while unreacted 3H-cAMP or 3H-cGMP remained in the supernatant. Radioactivity in the supernatant was measured in 2.5 mL of ultima gold liquid scintillation. At least eight concentrations of inhibitors (0.05–500 μM) were used in the presence of suitable substrates for the measurement of half maximal inhibitory concentration IC50 values, which were calculated by non-linear regression. Each measurement was repeated three times.