Aristolochic acid I: an investigation into the role of food crops contamination, as a potential natural exposure pathway.

Aristolochic acid I (AAI) is a potent nephrotoxic and carcinogenic compound produced by plants of the Aristolochiaceae family and thoroughly investigated as a main culprit in the etiology of Balkan endemic nephropathy (BEN). So far, the AAI exposure was demonstrated to occur through the consumption of Aristolochia clematitis plants as traditional remedies, and through the contamination of the surrounding environment in endemic areas: soil, food and water contamination. Our study investigated for the first time the level of AAI contamination in 141 soil and vegetable samples from two cultivated gardens in non-endemic areas, A. clematitis being present in only one of the gardens. We developed and validated a simple and sensitive ultra-high-performance liquid chromatography-ion trap mass spectrometry method for qualitative and quantitative AAI analysis. The results confirmed the presence of AAI at nanogram levels in soil and vegetable samples collected from the non-endemic garden, where A. clematitis grows. These findings provide additional evidence that the presence of A. clematitis can cause food crops and soil contamination and unveil the pathway through which AAI could move from A. clematitis to other plant species via a common matrix: the soil. Another issue regarding the presence of AAI, in a non-endemic BEN area from Romania, could underlie a more widespread environmental exposure to AAI and explain certain BEN-like cases in areas where BEN has not been initially described.

Differential methylation pattern of xenobiotic metabolizing genes and susceptibility to Balkan endemic nephropathy, in a cohort of Romanian patients.

A severe, chronic and irreversible kidney disease affecting discrete rural populations in the Balkan Peninsula countries, Balkan endemic nephropathy (BEN) has been a scientific puzzle for more than half a century. Many environmental and other factors have been suggested as the primary cause and recent significant findings have linked BEN to aristolochic acids, phytotoxins derived from the plant Aristolochia clematitis, found in high density in the endemic areas. However, given that the incidence of BEN is less than 10% in affected villages, and it tends to have a family aggregation, as yet unidentified genetic factors may also play a role. To further explore this possibility, a pilot study was initiated to investigate the DNA methylation of CYP1A1, CYP1A2, NAT1, NQO1 and GSTT1 in blood samples from a group of Romanian BEN patients, compared to healthy controls and non-BEN chronic kidney disease (CKD) subjects. Our study revealed a more pronounced hypomethylation pattern in BEN and non-BEN CKD groups, compared to the healthy control group at specific CpGs across all five genes interrogated. Average methylation across the five regions investigated indicated significant differences only at GSTT1, in both BEN patients (p = 0.028) and non-BEN disease subjects (p = 0.015), relative to healthy individuals. Since GSTT1 active genotype appears to be a common feature of Serbian and Romanian BEN patients, GSTT1 epigenetic variation and increased gene activity could act as a predisposing (co)factor in BEN populations from the affected countries. BEN and non-BEN CKD groups show similar methylation patterns with exception of GSTT1 CpG8 (p = 0.046).

Artificial device for extracorporeal blood oxygenation in rats.

Blood oxygenation devices are an essential component of any cardiopulomonary bypass circuit in various species of laboratory animals. When using larger animals like dogs or pigs, the human and pediatric blood oxygenators could be easily used, but the disadvantage of these species is the scarcity of biochemical and genetic assays for experimental follow-up. However, small rodents like rats have plenty of biochemical assays, but their size requires special oxygenators adapted for their small blood volume and often primed with blood of another animal or other physiological solution. We showed the new design of a blood oxygenator with direct blood-gas contact in an open circuit, specially designed for rats in which the blood oxygenation takes place in a slowly rotating plastic tube with blood spread onto its inner walls in a thin layer. The oxygenator is simple and efficient, does not require priming with the blood of another rat, has a small dead volume, is reusable, and easy to clean and sterilize.