Potential Mechanisms Involved in Chronic Kidney Disease of Unclear Etiology.

BACKGROUND AND OBJECTIVES: The etiology of chronic kidney disease of unclear etiology, also known as Mesoamerican nephropathy, remains unclear. We investigated potential etiologies for Mesoamerican nephropathy in an immigrant dialysis population. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Migrants with Mesoamerican nephropathy kidney failure (n=52) were identified by exclusion of known causes of kidney disease and compared using a cross-sectional survey with demographically similar patients with kidney failure from other causes (n=63) and age/sex/place of origin-matched healthy participants (n=16). Survey results were extended to the bench; C57BL/6 mice (n=73) received 10-15 weekly intraperitoneal injections of paraquat (a reactive oxygen species-generating herbicide) or vehicle. Kidney function, histology, and expression of organic cation transporter-2 (proximal tubule entry for paraquat) and multidrug and toxin extrusion 1 (extrusion pathway) were examined. Kidney biopsies from Nicaraguan patients with acute Mesoamerican nephropathy were stained for the above transporters and compared with patients with tubulointerstitial nephritis and without Mesoamerican nephropathy. RESULTS: Patients with Mesoamerican nephropathy and kidney failure were young agricultural workers, almost exclusively men; the majority were from Mexico and El Salvador; and they had prior exposures to agrochemicals, including paraquat (27%). After adjustment for age/sex, exposure to any agrochemical or paraquat was associated with Mesoamerican nephropathy kidney failure (odds ratio, 4.86; 95% confidence interval, 1.82 to 12.96; P=0.002 and odds ratio, 12.25; 95% confidence interval, 1.51 to 99.36; P=0.02, respectively). Adjusted for age/sex and other covariates, 1 year of agrochemical exposure was associated with Mesoamerican nephropathy kidney failure (odds ratio, 1.23; 95% confidence interval, 1.04 to 1.44; P=0.02). Compared with 16 matched healthy controls, Mesoamerican nephropathy kidney failure was significantly associated with exposure to paraquat and agrochemicals. Paraquat-treated male mice developed kidney failure and tubulointerstitial nephritis consistent with Mesoamerican nephropathy. Organic cation transporter-2 expression was higher in male kidneys versus female kidneys. Paraquat treatment increased organic cation transporter-2 expression and decreased multidrug and toxin extrusion 1 expression in male kidneys; similar results were observed in the kidneys of Nicaraguan patients with Mesoamerican nephropathy. CONCLUSIONS: Exposure to agrochemicals is associated with Mesoamerican nephropathy, and chronic exposure of mice to paraquat, a prototypical oxidant, induced kidney failure similar to Mesoamerican nephropathy.

Clevidipine : a state-of-the-art antihypertensive drug under the scope.

INTRODUCTION: Clevidipine butyrate is the first intravenous antihypertensive drug to be approved by the FDA over the last decade. This medication is approved for use in the USA, Australia and New Zealand, but is still pending for approval in Europe. It is a new agent that might change the current management for severe acute hypertension in the critical care, emergency and perioperative areas. AREAS COVERED: This systematic review summarizes the pharmacological and clinical characteristics of this third-generation dihydropyridine intravenous calcium channel blocker, and was done using the literature available from the first publication in 1999 up until now, including the pivotal trials that led to its approval. EXPERT OPINION: This agent is arterially selective, has an ultrashort half-life, with no CYP-mediated interactions with other medications and is easily titratable. These characteristics place it in a unique category compared with other commonly used antihypertensives. Clevidipine butyrate reaches target systolic blood pressure in more than 90% of patients, within 30 min. It has a low incidence of adverse reactions and is generally well tolerated. The main goal of this review is to provide healthcare providers with a comprehensive appraisal of this promising medication.