Risk assessment of agriculture impact on the Frío River watershed and Caño Negro Ramsar wetland, Costa Rica.

The Caño Negro Ramsar wetland is a conservation area of great natural and societal value, located in the lower part of the Frío River watershed in the north of Costa Rica. Its aquatic ecosystems may be considered vulnerable to pollution due to recent changes in land use toward agriculture. In 2011 and 2012, quarterly sampling was done at ten sites located in the middle and lower sections of the Frío River Basin that pass through crop areas and later drain into Caño Negro wetland.

Hazard prioritization and risk characterization of antibiotics in an irrigated Costa Rican region used for intensive crop, livestock and aquaculture farming.

Antibiotics alter the homeostasis of microbial communities and select for antibiotic-resistant bacteria in the wild. Thus, the accumulation of unnaturally high concentration of these substances in the environment due to their use in human activities can be regarded as a neglected form of pollution, especially in countries with agricultural-based economies. Qualitative and quantitative information on antibiotic usage in Costa Rica is scarce, hence the design and enforcement of prevention strategies and corrective measures is difficult.

Environmental hazards associated with pesticide import into Costa Rica, 1977-2009.

Raw pesticide import data from 1977 to 2009 obtained from the Ministry of Agriculture in Costa Rica were processed and analyzed. The quantity of specific active ingredients (a.i.

Pesticide exposure on sloths (Bradypus variegatus and Choloepus hoffmanni) in an agricultural landscape of Northeastern Costa Rica.

Between 2005 and 2008, wild Bradypus variegatus and Choloepus hoffmanni inhabiting an agricultural landscape and captive animals from a rescue center in Northeastern Costa Rica were studied to assess exposure to pesticides. A total of 54 animals were sampled: 42 wild sloths captured at an agricultural landscape and 12 captive animals from a rescue center. Pesticides' active ingredients were determined in three sample matrices: hair, aqueous mixture (paws' wash) and cotton gauze (mouth clean) based on multi-residue gas chromatography methods.

The use of rat lens explant cultures to study the mechanism of drug-induced cataractogenesis.

Lens explant cultures were used to assess the mechanism of drug-induced cataractogenic potential of NVS001, a peroxisome proliferator-activated receptor delta (PPARδ) agonist, which resulted in cataract in all treated animals during a 13-week rat study. Ciglitazone, a PPARγ agonist and cataractogenic compound, was used as a positive control to validate this model. Rat lenses were extracted and cultured in medium supplemented with antibiotics for 24-h preincubation pretreatment.

Monitoring pesticide use and associated health hazards in Central America.

We established methods for monitoring pesticide use and associated health hazards in Central America. With import data from Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama for 2000-2004, we constructed quantitative indicators (kg active ingredient) for general pesticide use, associated health hazards, and compliance with international regulations. Central America imported 33 million kg active ingredient per year.

Organ slice viability extended for pathway characterization: an in vitro model to investigate fibrosis.

Liver slice viability is extended to 96 h for rat, expanding the use of this in vitro model for studying mechanisms of injury and repair, including pathways of fibrosis. The contributing factors to increased organ slice survival consist of the use of a preservation solution for liver perfusion and slice preparation, obtaining rats that are within the weight range of 250-325 g, placing a cellulose filter atop the titanium mesh roller-insert to support the slice, and maintaining the slices in an optimized culture medium which is replaced daily. The liver slices remain metabolically active, synthesizing adenosine triphosphate (ATP), glutathione, and glycogen, and exhibit preserved organelle integrity and slice morphology.