Yacoub M. Irshaid

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The O-demethylation of dextromethorphan (DMT) to dextrorphan (DRP) was studied in 241 unrelated, healthy Jordanian volunteers (171 males, 70 females). Urine was collected for 8 h following a single oral dose of DMT bromhydrate 30 mg. A thin-layer chromatographic (TLC) technique was used to identify the metaboliser phenotype. The frequency of the poor(More)
A sample of prescription orders received from outpatient departments by a hospital pharmacy in Asir, Saudi Arabia, were analysed over 1 year for the essential elements of prescriptions. The prescriber's name, address and signature were on 83.3%, 9.6% and 81.9% of prescriptions respecti-vely. The patient's name, age and sex were on 94.6%, 77.3% and 51.3%. No(More)
1. Multiple forms of UDP-glucuronosyltransferase (UDPGTs) have been demonstrated in the livers of all mammalian species that have been studied. Rat liver possesses at least eight different isozymes and human liver has at least five different forms which have been identified. 2. Endogenous substrates (e.g., steroids) are helpful in distinguishing UDPGTs as(More)
OBJECTIVES The purpose of this study was to determine the genotype/allele frequencies of C677T and A1298C polymorphisms of methylenetetrahydrofolate (MTHFR) gene in Jordanian rheumatoid arthritis (RA) patients. In addition, the association between MTHFR gene C677T and A1298C polymorphisms and response to and toxicity of methotrexate (MTX) was evaluated. (More)
The glucuronidation of 6-hydroxylated bile acids by human liver microsomes has been studied in vitro; for comparison, several major bile acids lacking a 6-hydroxyl group were also investigated. Glucuronidation rates for 6 alpha-hydroxylated bile acids were 10-20 times higher than those of substrates lacking a hydroxyl group in position 6. The highest rates(More)
The frequency distribution of the 8-h urinary ratio of log metoprolol/α-hydroxymetoprolol was assessed in 65 healthy, unrelated Jordanian volunteers. There was no apparent bimodality in the frequency distribution of this ratio among the subjects studied. The frequency of the poor metabolizer phenotype of metoprolol α-hydroxylation was 1.5% (one subject).(More)
A human liver microsomal UDP glucuronosyltransferase (UDPGT) that demonstrates reactivity with estriol (pI 7.4 UDPGT) has been purified to homogeneity and characterized further. No activity toward morphine, 4-hydroxybiphenyl, bilirubin, or tripelennamine was observed. The estriol UDPGT shows immunoreactivity with antibodies raised against rat hepatic(More)
OBJECTIVE To determine the frequency of major NAT2 alleles and genotypes among the Jordanian population. METHODS DNA samples from 150 healthy Jordanian volunteers were analyzed by polymerase chain reaction followed by restriction fragment length polymorphism assays (PCR-RFLP) to determine the frequency of four major alleles: NAT2*4, NAT2*5, NAT2*6 and(More)
The ability to oxidise trimethylamine (TMA) to trimethylamine N-oxide (TMAO) is distributed polymorphically within a British white population with the majority of individuals excreting greater than 90% of total urinary TMA as TMAO. The opposite extreme is characterised by a rare inborn error of TMA N-oxidation known as the fish-odour syndrome. However there(More)