Toxicity of silver nanoparticles on different tissues in adult Danio rerio.

Although silver nanoparticles (AgNP) are among the most studied nanomaterials by virtue of their broad application in many areas, little is known about their overall toxicity to aquatic organisms after their contamination of the water environment. This study aimed to analyze the effect of the exposure (96 h) to different AgNP concentrations on Danio rerio (zebrafish) tissues. AgNP were synthesized and characterized by transmission electron microscopy (TEM), showing spherical AgNP of 30.00 ± 16.80 nm size. The effects of different AgNP concentrations (1, 3, and 5 µg L-1) on brain, muscle, gill, and liver tissues of zebrafish were investigated. The results show a significant decrease in brain and muscle acetylcholinesterase (AChE) activity. Liver and gill catalase (CAT) activity also decreased significantly. At the highest exposure concentration, muscle AChE was more inhibited (37.3%) than brain AChE (26.4%) and gill CAT was more inhibited (67.4%) than liver CAT (51.2%). D. rerio also showed gill morphological changes such as fusion of secondary lamellae, curvature, dilated marginal channel, and epithelial lifting. This study indicates that gill CAT together with morphological studies are potential biomarkers for AgNP.

Infiltrating gastric adenocarcinoma with disseminated osteoblastic metastases.

We report the case of a man with a diagnosis of invasive gastric adenocarcinoma associated with scattered osteoblastic metastases. This 65-year-old patient was admitted with nausea, vomiting and abdominal pain, in addition to loss of weight (13 Kg in 3 months). Upper digestive endoscopy revealed extensive infiltrating changes in the body of the stomach, and histopathologic data confirmed the diagnosis of a Borrmann IV gastric adenocarcinoma. Complementary exams were indicative of a gastric cancer with bone metastases, characterized by disseminated osteoblastic images of the scintigraphy of the skeleton. Palliative chemotherapy was the treatment of first choice. High serum levels of CA 19-9, CEA and alkaline phosphatase can constitute useful indicative tools of this challenging condition. Images from a scintigraphy study of the skeleton can characterize the type and extension of bone metastases. The aim of this case study is to report a case of a very uncommon condition, considering that disseminated osteoblastic metastases rarely develop in this kind of tumor.

[A 56-year-old woman with ampullary adenocarcinoma and acute pancreatitis]. / Mujer de 56 años con adenocarcinoma de la ampolla de Vater y pancreatitis aguda.

This challenging condition has scarcely been reported on. A 56-year-old woman was admitted with jaundice, and laboratory data were indicative of pancreatitis, which recurred in spite of adequate clinical and nutritional management. The patient was an overweight diabetic using metformin, who had antecedents of cholelithiasis and recent cholecystectomy. Clinical and laboratory features were not conclusive about the cause of this acute pancreatitis. However, imaging data contributed to diagnosis suspicion, and the histopathology study of the transpapillary biopsy confirmed the ampullary adenocarcinoma. Whipple's surgery was the procedure of choice, associated with radical lymphadenectomy, followed by an uneventful outcome. Recrudescence of signs and symptoms of acute pancreatitis, with elevated serum levels of bilirrubins and of hepatic canalicular enzymes, should enhance the suspicion index about periampullary tumors. High levels of CA 19-9 can constitute a useful marker of this condition. Transpapillary biopsy can characterize the diagnosis of ampullary malignancies.