Cannabis and the exocannabinoid and endocannabinoid systems. Their use and controversies

Cannabis (marijuana) is one of the most consumed psychoactive substances in the world. The term marijuana is of Mexican origin. The primary cannabinoids that have been studied to date include cannabidiol and delta-9-tetrahydrocannabinol, which is responsible for most cannabis physical and psychotropic effects. Recently, the endocannabinoid system was discovered, which is made up of receptors, ligands and enzymes that are widely expressed in the brain and its periphery, where they act to maintain balance in several homeostatic processes. Exogenous cannabinoids or naturally-occurring phytocannabinoids interact with the endocannabinoid system. Marijuana must be processed in a laboratory to extract tetrahydrocannabinol and leave cannabidiol, which is the product that can be marketed. Some studies suggest cannabidiol has great potential for therapeutic use as an agent with antiepileptic, analgesic, anxiolytic, antipsychotic, anti-inflammatory and neuroprotective properties; however, the findings on cannabinoids efficacy and cannabis-based medications tolerability-safety for some conditions are inconsistent. More scientific evidence is required in order to generate recommendations on the use of medicinal cannabis.

Isquemia fría prolongada, factor para rechazo agudo del injerto en trasplante renal cadavérico / Prolonged cold ischemia: risk factor for acute rejection in renal grafting of cadaveric kidney transplantation

Introducción: Es conocido que la exposición del injerto renal a tiempo prolongado de isquemia fría se asocia con rechazo agudo. Dado que no se encontró evidencia del tema en México, el objetivo de este estudio fue determinar el papel del tiempo de isquemia fría prolongado sobre el injerto en el trasplante renal cadavérico en población mexicana. Material y métodos: Estudio observacional, retrospectivo, transversal y analítico para el que se seleccionaron los expedientes de pacientes con trasplante renal entre julio de 1994 y junio de 2004. Se realizó análisis de diferentes variables para determinar su efecto sobre el rechazo agudo, entre ellas el tiempo prolongado de isquemia fría (≥ 12 horas). Resultados: De los 425 transplantes realizados, 33 fueron de donador cadavérico; 10 pacientes tuvieron rechazo agudo. El tiempo prolongado de isquemia fría (OR = 8.4, IC = 1.5-44.2, p = 0.02) y la combinación azatioprina (AZA)-prednisona (PDN)- ciclosporina (CSA) (OR = 9.1, IC = 1.5-49.4, p = 0.02) fueron factores de riesgo para rechazo agudo. El uso de antiCD25 (OR = 0.6, IC = 0.009-0.37, p = 0.001) y la combinación mofetil micofenolato (MMF)-PDN-CSA (OR = 0.1, IC = 0.02-0.65, p = 0.02) fueron factores protectores de rechazo agudo. Conclusiones: En una población mexicana, el tiempo de isquemia fría prolongado y la combinación AZA-PDN-CSA fueron factores de riesgo para rechazo agudo, mientras que el uso de antiCD25 y la combinación MMF-PDN-CSA fueron protectores para rechazo agudo en trasplantes renales de donadores cadavéricos.

BACKGROUND: Exposure of renal grafting to prolonged cold ischemia time (CIT) and the association with acute rejection (AR) are known. However, there is no evidence in Mexico about this topic. Thus, the objective of this study was to evaluate prolonged CIT as a risk factor for AR in renal grafting of cadaveric kidney transplantation in a Mexican population. METHODS: A cross-sectional study was carried out. Clinical files of patients undergoing renal grafting using cadaveric kidneys were reviewed from July 1994-June 2004. Prolonged CIT (=12 h) as a risk factor for AR was evaluated. Other related variables were also examined. RESULTS: From 425 kidney transplantations, only 33 cases were cadaveric. Ten patients had AR. Prolonged CIT (OR 8.4; CI 1.5-44.2, p = 0.02) and azathioprine (AZA)-prednisone (PDN)-cyclosporine (CSA) combination (OR 9.1; CI 1.5-49.4, p = 0.02) were risk factors for AR. Anti-CD25 use (OR 0.6; CI 0.009-0.37, p = 0.001) and mycofenolate mofetil (MMF)-PDN-CSA combination (OR 0.1; CI 0.02-0.65, p = 0.02) were protective factors for AR. CONCLUSIONS: In a Mexican population, prolonged CIT and AZA-PDN-CSA combination were risk factors for AR. Meanwhile, anti- CD25 use and MMF-PDN-CSA combination were protective factors for AR in cadaveric kidney transplantations.