Anxiolytic-like Effect of Chrysin on Female Zebrafish is Likely Mediated by α5 subunits of GABAA Receptors.

Chrysin (5,7-dihydroxyflavone) is a natural flavonoid with potential anxiolytic-like effects in preclinical models. Acute treatment with this molecule (0 - 10 mg/kg) produced a biphasic dose-response in the zebrafish light/dark test (LDT), with anxiolytic-like effect at low doses and anxiogenic-like effects at high doses. Chrysin (1 mg/kg) decreased anxiety-like behavior in the zebrafish novel tank test (NTT), but did not prevent the anxiogenic effects of acute stress.

Oogenesis and in vitro reproduction of the twospot astyanax Astyanax bimaculatus (Linnaeus, 1758) exposed to conspecific alarm substance.

Stress situations can be essential to trigger reproduction in fish; however, it may also inhibit it. One of those situations involves the release of the conspecific alarm substance (CAS), a natural stressor, into the water by specific fish epidermal cells after a predator attack. Little is known about the effects of that substance on fish reproduction.

Convenient enzymatic resolution of (R,S)-2-methylbutyric acid catalyzed by immobilized lipases.

The application of several immobilized lipases has been explored in the enantioselective esterification of (R,S)-2-methylbutyric acid, an insect pheromone precursor. With the use of Candida antarctica B, using hexane as solvent, (R)-pentyl 2-methylbutyrate was prepared in 2 h with c 40%, ee 90%, and E = 35, while Thermomyces lanuginosus leads to c 18%, ee 91%, and E = 26. The (S)-enantiomer was obtained by the use of Candida rugosa or Rhizopus oryzae (2-h reaction, c 34% and 35%, ee 75 and 49%, and E = 10 and 4, respectively).

Pharyngeal swallowing phase and chronic cough.

Introduction:  The act of swallowing depends on a complex and dynamic process which uses common structures to the act of breathing; respiratory problems can cause swallowing difficulties.

Aim:  To assess the swallowing pharyngeal phase in patients with chronic cough.

Method:  Retrospective study with 15 patients of both genders, patients with chronic cough and risk factors for aspiration defined by the pneumologic diagnosis.

Evaluation of the catalytic activity of lipases immobilized on chrysotile for esterification.

In the present work, the ester synthesis in organic media catalyzed by lipases immobilized on chrysotile was studied. Lipases of different sources (Mucor javanicus, Pseudomonas cepacia, Rhizopus oryzae, Aspergillus niger and Candida rugosa) were immobilized on chrysotile, an inexpensive magnesium silicate, and used for esterification of hexanoic, octanoic and lauric acid with methanol, ethanol, 1-butanol and 1-octanol at 25 C in hexane as solvent. The best results were obtained with Mucor javanicus lipase and lauric acid giving yields of 62-97% of ester.