Lethal and sublethal effects of the emerging contaminant oxytetracycline on the embryo-larval development of Rhinella arenarum.

The antibiotic oxytetracycline (OTC) is commonly used in animal production and can enter aquatic ecosystems, causing adverse effects on non-target species. The aim of this work was to evaluate the lethal and sublethal effects of OTC on the embryonic and larval period of Rhinella arenarum, through standardized bioassays and oxidative stress (catalase-CAT-, superoxide dismutase-SOD-, glutathione S-transferase-GST-, reduced glutathione-GSH- and lipid peroxidation-TBARS-), neurotoxicity (acetylcholinesterase-AChE- and butyrylcholinesterase-BChE-) and genotoxicity (micronuclei test) biomarkers. Mortality was time and stage dependent, being the embryos (504 h-LC50 = 64.

Development and Diagnostic Accuracy of a Breath Test for Pancreatic Exocrine Insufficiency in Chronic Pancreatitis.

Objective: To develop a ¹³C-labeled substrate breath test by defining the optimal ¹³C-labeled substrate, substrate dose, test meal, and duration of the test and evaluating its accuracy for the diagnosis of pancreatic exocrine insufficiency (PEI) in chronic pancreatitis (CP).

Methods: Five consecutive prospective comparative studies in patients with known advanced CP and healthy controls were performed to develop the optimal breath test. Coefficient of fat absorption was used as the reference method.

Further solid-phase microextraction-gas chromatography-mass spectrometry applications: "on-fibre" and aqueous photodegradation of nitro musks.

Photodegradation kinetics of four nitro musks (musk xylene, musk tibetene, musk ketone and musk moskene) in solid-phase microextraction (SPME) fibres ("photo-SPME") and in an aqueous system were studied by means of gas chromatography-mass spectrometry (MS) detection. Musks fragrances were extracted from aqueous solutions using SPME fibres that subsequently were exposed to different UV irradiation times, generating photoproducts easily characterized by their mass spectra. Aqueous photodegradation studies followed by SPME were also performed and compared to photo-SPME.

Study of the photoinduced degradation of polycyclic musk compounds by solid-phase microextraction and gas chromatography/mass spectrometry.

Polycyclic musks are widely used synthetic fragrances that have been identified during the last few years in biota samples and environmental matrices. Nevertheless, there is a lack of information concerning the photodegradation behavior of these compounds. In this work, the photoinduced degradation of six polycyclic musk compounds (Cashmeran, Celestolide, Phantolide, Galaxolide, Traseolide and Tonalide) was studied using a solid-phase microextraction (SPME) fiber as support.