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Computed Tomography
Published in Stanton H. Cohn, Non-Invasive Measurements of Bone Mass and Their Clinical Application, 2020
Harry Genant, Douglas Boyd, Dov Rosenfeld, Yanis Abols, Christopher E. Cann
For preliminary evaluation, the EMI head unit was used to study phantoms constructed to simulate mineral, soft tissue, and fat, either separately or in composite form. A dipotassium hydrogen phosphate (K2HPO4) solution was chosen for standardization, since it has absorption properties11 similar to calcium hydroxyapatite (Ca10[PO4]6[OH]2). Water was used to simulate soft tissue and ethyl alcohol (C2H5OH) to simulate fat.12-14 Single chamber cylinders (16 mm diameter) were filled with combinations of these solutions. Coaxial dual chamber cylinders were constructed with the outer circumferential chamber (42 or 33 mm diameters) containing high concentrations of phosphate solution and the inner chamber (31 or 22 mm diameters) containing lower concentrations, to simulate cancellous bone. Variable amounts of alcohol were added to the central chamber to simulate marrow fat. Monitor displays of single and coaxial phantoms and the corresponding digital print-outs were used for quantification.
Purification of Copper/Zinc Superoxide Dismutase
Published in Robert A. Greenwald, CRC Handbook of Methods for Oxygen Radical Research, 2018
Joe V. Bannister, William H. Bannister
Bovine or human red cells are lysed overnight at 4°C with an equal volume of distilled water containing 0.1% (v/v) Triton® X-100. A mixture of ethanol-chloroform (3:1, v/v) is also chilled to −20°C overnight. To the lysate is then added one half volume of the organic solvent mixture in small portions with continuous stirring and the mixture is left standing for 30 min at 4°C. One fifth volume of 0.15 M NaCl is then added with stirring, and the mixture is centrifuged at 2000 g for 60 min at 4°C. The SOD is in the supernatant and can be precipitated by addition of volume of a saturated solution of lead acetate or zinc acetate. (Lead acetate is best used for large-scale preparations of the enzyme from bovine zinc acetate for small-scale preparations from human red cells.) Human CuZn SOD has one free cysteine per subunit,8 and the use of zinc acetate precipitation is to obviate thiol oxidation. The lead acetate precipitate is collected by centrifugation and is extracted twice with 0.3 M phosphate buffer, pH 6.0. During the addition of saturated zinc acetate, the pH of the solution is maintained at neutral by addition of solid Tris. The zinc acetate precipitate is extracted twice with 0.3 M pyrophosphate-acetic acid buffer, pH 7.0. As an alternative to lead or zinc acetate precipitation, solid dipotassium hydrogen phosphate can be added to the supernatant obtained after addition of the ethanol-chloroform mixture. This results in phase separation and the protein is extracted from the lighter phase by precipitation with acetone.4 The final protein extract is dialyzed against 20 mM Tris buffer, pH 7.8, at 4°C.
Effect of roll compaction pressure on the properties of high drug-loaded piracetam granules and tablets
Published in Drug Development and Industrial Pharmacy, 2022
The quantification of piracetam in dissolution samples was performed by HPLC with UV-detector. The HPLC-column (250 mm × 4.6 mm) is filled with 5 µm size C18 (RP18, ODS, Octadecyl) silica particles (YMC-Pack ODS-AQ; YMC Co., Ltd., Ishikawa, Japan). After the injection of 10 µL of dissolution sample, the mobile phase of acetonitrile and water solution (1 g/L) of dipotassium hydrogen phosphate (10:90) adjusted to pH 6.0 ± 0.05 by water solution of phosphoric acid was used at 1.0 ml/min flow rate. The signal was detected at 205 nm, and the concentration of piracetam was determined in accordance with the area under the piracetam peak in comparison with the standard solution. The released drug amount in percentage (presented as Av.±SD of twelve (n = 12) tested tablets) was plotted versus time.
Plasma protein binding, metabolism, reaction phenotyping and toxicokinetic studies of fenarimol after oral and intravenous administration in rats
Published in Xenobiotica, 2021
Kajal Karsauliya, Ashish Kumar Sonker, Manisha Bhateria, Isha Taneja, Anshuman Srivastava, Manu Sharma, Sheelendra Pratap Singh
FNL (CAS no. 60168-88-9, purity ≥ 98.0%) was procured from Sigma Aldrich (St Louis, MO) whereas, Centchroman (internal standard, IS) was a generous gift from CSIR-Central Drug Research Institute, Lucknow, India. The chemical structures of FNL and IS are represented in Figure 1. Propranolol, ethylenediaminetetraacetic acid (EDTA), ketoconazole, LC grades of acetonitrile and formic acid were supplied by Sigma Aldrich (St. Louis, Germany). Dipotassium hydrogen phosphate anhydrous and potassium dihydrogen phosphate were purchased from Merck Life Sciences Pvt. Ltd (Mumbai, India). Magnesium chloride was procured from Loba Chemie Pvt. Ltd (Mumbai, India). NADPH was procured from SRL Pvt. Ltd (Mumbai, India). Liver microsomes (Catalogue number: RTMCPL (rat liver microsomes) and HMMCPL (human liver microsomes)) and recombinant human CYP450 isoforms (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4) were purchased from Invitrogen (Thermo Fisher Scientific, Bangalore, India). Milli Q water was obtained from a Millipore gradient water purification system (Millipore India Pvt. Ltd, New Delhi, India). MultiScreen Solvinert Filter Plate (96-well device with 0.45 µm PTFE membranes) were purchased from Millipore Corporation (Milford, CT). Blank plasma was obtained from healthy adult Wistar rats procured from the animal facility of the CSIR-Indian Institute of Toxicology Research, Lucknow, India. For maintenance, experimental studies, euthanasia, and disposal of the carcass, prior approval was taken from Institutional Animal Ethics Committee (IITR/IAEC/03/19). Human blank plasma was offered by healthy volunteers.
Hydrogen/deuterium exchange mass spectrometry and computational modeling reveal a discontinuous epitope of an antibody/TL1A Interaction
Published in mAbs, 2018
Richard Y.-C. Huang, Stanley R. Krystek, Nathan Felix, Robert F. Graziano, Mohan Srinivasan, Achal Pashine, Guodong Chen
Trimeric human TL1A and anti-hTL1A IgG4 mAb, mAb1, were expressed from CHO cells in house. The TL1A construct contains a His-tagged isoleucine-zipper motif in the N-terminal region that facilitates the trimer formation.33 N-glycan sites were identified at N135 and N231. Trimetric TL1A was purified by Ni-affinity chromatography, buffer exchanged into phosphate-buffered saline (PBS), and analyzed by SEC (Figure S1). The concentrations of both hTL1A and mAb1 were determined by UV 280 nm absorbance. Dipotassium hydrogen phosphate, monopotassium phosphate, Tris(2-carboxyethyl)phosphine hydrochloride (TCEP.HCl) and deuterium oxide were purchased from Sigma-Aldrich (St. Louis, MO). P1 synthetic peptide, HHHHHHIIKIIK, was from Anaspec (Fremont, CA).