The rs776746 variant of CYP3A5 is associated with intravenous midazolam plasma levels and higher clearance in critically ill Mexican paediatric patients.

What Is Known And Objective: Midazolam is a drug that is metabolized by cytochrome P450 (CYP450) enzymes, particularly CYP3A4 and CYP3A5. The presence of single-nucleotide polymorphisms (SNPs) in the genes encoding these enzymes, such as CYP3A4*1B which is associated with low enzyme expression and activity and CYP3A5*3, has been associated with decrease in enzymatic activity and reduced drug clearance, with potential effects on drug levels and/or toxicity. The present study was conducted to determine the frequencies of the allelic variants of the CYP3A4 (rs2740574) and CYP3A5 (rs776746) genes and their effects on the plasma levels and clearance of intravenous midazolam in critically ill Mexican paediatric patients.

Heterozygous Genotype rs17580 AT (PiS) in is Associated with COPD Secondary to Biomass-Burning and Tobacco Smoking: A Case-Control and Populational Study.

Purpose: The protease inhibitor S (PiS) and Z (PiZ) variants have been stated as the only genetic cause of chronic obstructive pulmonary disease (COPD) in Caucasians. However, its frequency in admixed populations is low. We aimed to identify genetic susceptibility between PiS (rs17580) and PiZ (rs28929474) polymorphisms with COPD related to tobacco smoking and biomass-burning smoke as well as to determine its frequencies in Mestizo and Amerindian populations from Mexico.

Analysis of gene allelic variants can predict ifosfamide toxicity in Mexican paediatric patients.

Ifosfamide (IFA) is an effective antineoplastic for solid tumours in children, although it is associated with high levels of systemic toxicity and causes death in some cases. The aim of this study was to determine whether the presence of certain allelic variants of genes , , and increases the risk of toxicity in children with solid tumours treated with ifosfamide. A total of 131 DNA samples were genotyped by real-time polymerase chain reaction (RT-PCR) using TaqMan probes.

[Factors involved in host-pathogen interaction for the risk of Hodgkin lymphoma induced by Epstein Barr virus].

Hodgkin lymphoma (HL) is a neoplasm characterized by malignant cells called Reed Sternberg and Hodgkin's cells in the lymphatic system. Such cells comprise 1% of the tumor while the remainder is made up of lymphocytes, histiocytes, eosinophils and plasma non-neoplastic cells. The annual global incidence of HL is 3-10/100,000 inhabitants and is most commonly found in young adults.

[Clinical pathological study of craniopharyngioma. Fifteen years at the National Institute of Neurology and Neurosurgery "Manuel Velasco Suárez"].

Background: Craniopharyngioma is a sellar region benign cyst It's frequency ranges from 1.2% to 4.6% of all brain tumors.

[Cytochrome P450 and NAT2 polymorphisms and drug metabolism in DOTS].

It has been described an increase of the frequency of Directly Observed Therapy Short-course (DOTS) failure in countries with high rates of mycobacterial drug resistance. This increase could be due to the standardized doses of DOTS results in low or insufficient dosage of drugs in plasma. Several members of cytochrome P450 enzymes superfamily could explain the variations on acetylation velocity and in drug disposition.