King Faisal Specialist Hospital & Research Centre

About: King Faisal Specialist Hospital & Research Centre is a healthcare organization based out in Riyadh, Saudi Arabia. It is known for research contribution in the topics: Medicine & Detection limit. The organization has 58 authors who have published 157 publications receiving 3527 citations.

Influence of the Alcoholic Modifier on the Enantioseparation of Organophosphonate Derivatives on Cellulose tris(3,5-Dimethylphenylcarbamate) Chiral Stationary Phase Under Normal Phase Mode

Abstract: The enantiomers of fifteen O,O-dialkyl-2-benzyloxycarbonyl- aminoarylmethyl-phosphonates are directly separated on cellulose tris(3,5-dimethyl-phenylcarbamate) chiral stationary phase using different alcohols as organic mobile phase modifier. The influence of the position and properties of substituents in benzene ring, the length and steric hindrance of alkoxyl groups of the phosphonate ester on the chiral separation were discussed using different alcohol modifiers namely, ethanol, n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol. The study indicates that with the use of different alcohol modifiers in mobile phase, the capacity factor (k) was in the order of k EtOH

Simple HPLC Method for the Determination of Enalaprilat in Human Plasma

Abstract: A simple and reliable isocratic reversed phase high performance liquid chromatography (HPLC) method for the determination of enalaprilat in human plasma is described. After plasma extraction, enalaprilat is analyzed using a µ Bondapak C18 column kept at 50°C. The mobile phase consists of 60% A (0.01 M KH2PO4, pH 4.0) and 40% B (80% of 50:50 CH3CN:CH3OH + 20% A) v/v. Enalaprilat is monitored by UV detection at 205 nm. The method is quite simple and sufficiently sensitive, with a limit of quantitation of 5 ng/mL and limit of detection of 1 ng/mL; within day and between‐days assays showed a relative standard deviation (RSD) below 15%.

Thermodynamic study of the enantiomeric resolution of flurbiprofen by HPLC using Chiralpak AD-RH column.

Abstract: The chiral resolution of (+/-)-flurbiprofen was achieved using water-acetonitrile (60:40, v/v) containing 0.1% acetic acid on a Chiralpak AD-RH column at 20 degrees C. The enantio-resolution was studied with different percentages of acetonitrile. Thermodynamic parameters (enthalpy, entropy and free energy) were calculated by carrying out the enantio-resolution experiments at 0 to 60 degrees C. The enantio-resolution was found to be exothermic in nature. Attempts have been made to explain the mechanism of chiral resolution of flurbiprofen on the Chiralpak AD-RH column.

Synthesis and benzodiazepine receptor binding activity of 2, 9-disubstituted quinolino[2', 3'-5, 4](3-pyrazolino)[3, 2-b]purin-4-ones.

Abstract: 2, 9-Disubstituted quinolino[2', 3'-5, 4](3-pyrazolino)pyrimidin-2-ones and purin-4-ones were synthesized and their benzodiazepine receptor activity was evaluated for their ability to displace [(3)H]R015-1788 from its specific binding in bovine brain membranes. Compound 5c caused 83 +/- 8 %inhibition in [(3)H]R015-1788 specific benzodiazepine receptor binding followed by compounds 5f, 5h, and 5i while other analogs were inactive at 10 microM concentration.

Frequency and Clinical Impact of KRAS Mutations in Patients with Colorectal Cancer from the Middle East

Abstract: Background : Colorectal cancer (CRC) is a significant healthcare burden worldwide and in the Middle East (ME). KRAS mutation confers resistance to epidermal growth factor receptor (EGFR) inhibitors in the treatment of advanced CRC. Data regarding the rate of KRAS mutation from the ME are scattered and scarce. We aim to collect and review all sizable studies evaluating the frequency of KRAS mutations in CRC patients from the ME. Method : A Pubmed and Google Scholar search was conducted using keywords including KRAS, K-ras, colorectal cancer and Middle East, along with names of each ME country. Studies including over 90 patients were included in the review. Result : Eleven studies containing more than 90 patients were identified. Among all eleven studies, KRAS mutation rate ranged from 13 to 56%. Five studies reported KRAS mutation rate in M1 stage either exclusively or as part of subgroup analysis. In these studies, mutations were found in 8-45% of cases. KRAS mutations were associated with female gender, M1 stage and high CEA in 3, 2, and 1 studies respectively. Conclusion : There is a broad range of variability in KRAS mutation rate reported in different studies from the ME. This may have been due to small number of patients in the studies and lack of centralized testing for KRAS mutations. Larger and more coordinated studies from the ME population are required to ascertain the accuracy of KRAS mutation rate.