Comparison of the Sensitivity of Tetragonisca angustula (Apidae-Meliponini) and Apis mellifera (Apidae-Apini) to Three Insecticides (Malathion, Imidacloprid, and Fipronil) Used in Costa Rica.

The decline of insect pollinators is a significant concern within the current biodiversity crisis. The paradox between the benefits that these animals represent to humans and the evidence of human activities driving their extinction calls for the urgent protection of bees. To address the role of chemical pollution in this scenario, we assessed the acute toxicity as well as four biomarker responses (cholinesterase [ChE], glutathione S-transferase, catalase, and lipid peroxidation [LPO]) elicited by dietary 24-h exposure to three insecticides (malathion, imidacloprid, and fipronil) on the stingless neotropical bee Tetragonisca angustula and the honeybee Apis mellifera. Malathion was the most toxic substance to both species, with 48-h median lethal doses (LD50s) of 0.25 ng/bee to A. mellifera and 0.02 ng/bee to T. angustula. Fipronil was also highly toxic and presented a similar toxicity to both species, with 48-h LD50s of 0.5 ng/bee (A. mellifera) and 0.4 ng/bee (T. angustula). Imidacloprid had the lowest acute toxicity with a 48-h LD50 of 29 ng/bee for A. mellifera, whereas T. angustula tolerated exposure higher than 35 ng/bee. Apparent biomarker responses were observed in bees of both species that survived exposure to higher concentrations of malathion (ChE inhibition) and fipronil (increased LPO). Our results suggest that specific sensitivity to insecticides varies greatly among compounds and pollinator species, but the use of different representative species can facilitate the prioritization of substances regarding their risk to pollinators. Further research is necessary to better characterize the risk that pesticides represent in neotropical agricultural landscapes. Environ Toxicol Chem 2023;42:1022-1031. © 2023 SETAC.

Giant Rasmussen's aneurysm in a 9-year-old boy: A case report.

Rasmussen's aneurysm is a pseudoaneurysm caused by tuberculosis, when cavitation occurs adjacent to a pulmonary artery, which can be lethal. It is a rare complication usually affecting adults. This is a case of an 9-year-old boy initially admitted for pneumonia that developed hemoptysis during admission. Chest X-ray done after this episode showed development of a left hilar mass not present in the previous studies. A chest CT with contrast subsequently revealed a saccular aneurysm arising from the left lower lobe pulmonary artery adjacent to a cavity, a Rasmussen's aneurysm. The patient was treated conservatively with continuation of anti-TB medication and serial monitoring due to the size of the aneurysm being less than 6 cm and spontaneous resolution of the hemoptysis. This report stresses that a Rasmussen's aneurysm should always be in the differential diagnosis of a hilar mass in a patient with hemoptysis, regardless of the patient's age.

A new minimally invasive porcine model for the study of intrahepatic bile duct dilatation.

BACKGROUND: Endoscopic ultrasound (EUS) procedures are becoming more frequent nowadays and novel techniques are on the rise. These procedures require high technical experience and complex endoscopic skills. The goal of this study was to develop a new minimally invasive animal model of bile duct dilatation in the pig, in order to offer a new tool for endoscopic and surgical therapy training and to test new therapeutic strategies. METHODS: Twenty-five female pigs underwent laparoscopic surgery in order to perform a common hepatic duct ligation. A pre- and postoperative biochemical analyses were performed: glucose, albumin, total bilirubin (TBil), gamma glutamyl transferase (GGT), alkaline phosphatase, and alanine aminotransferase were measured. Surgical time and intra- and postoperative complications were registered. Five to six days after surgery, an EUS was performed to measure intrahepatic duct size (mm). Distance from the bile duct to the EUS transductor was also recorded (mm). T-student for quantitative variables was applied. Statistical significance was defined as p value ≤ 0.05. RESULTS: The mean surgical time was 29.5 ± 14.9 min. In five pigs (20%), some mild intraoperative problems occurred. A severe postoperative complication occurred in one animal (4%). No postoperative mortality was registered. Postoperative serum analyses showed an increase in total bilirubin (p = 0.005) and gamma glutamyl transferase levels (p = 0.001). Postoperative EUS showed dilatation of the intrahepatic bile duct in 76% of pigs, with a mean diameter of 9.6 ± 3.6 mm (distance from the gastric wall of 17.0 ± 6.4 mm). CONCLUSION: The surgical procedure described here is a safe technique to induce dilatation of the intrahepatic bile ducts in the pig, with a minimally invasive approach and a high efficacy rate. This animal model might be useful for EUS techniques training and for evaluating new therapeutic approaches.