The relation between changes in brain and plasma concentrations of neurosteroids and the function and structure of ␥-aminobutyric acid type A (GABA A ) receptors in the brain during pregnancy and after delivery was investigated in rats. In contrast with plasma, where all steroids increased in parallel, the kinetics of changes in the cerebrocortical concentrations of progesterone, allopregnanolone (AP), and allotetrahydrodeoxycorticosterone (THDOC) diverged during pregnancy. Progesterone was already maximally increased between days 10 and 15, whereas AP and allotetrahydrodeoxycorticosterone peaked around day 19. The stimulatory effect of muscimol on 36 Cl ؊ uptake by cerebrocortical membrane vesicles was decreased on days 15 and 19 of pregnancy and increased 2 days after delivery. Moreover, the expression in cerebral cortex and hippocampus of the mRNA encoding for ␥2L GABA A receptor subunit decreased during pregnancy and had returned to control values 2 days after delivery. Also ␣1,␣2, ␣3, ␣4, ␤1, ␤2, ␤3, and ␥2S mRNAs were measured and failed to change during pregnancy. Subchronic administration of finasteride, a 5␣-reductase inhibitor, to pregnant rats reduced the concentrations of AP more in brain than in plasma as well as prevented the decreases in both the stimulatory effect of muscimol on 36 Cl ؊ uptake and the decrease of ␥2L mRNA observed during pregnancy. These results indicate that the plasticity of GABA A receptors during pregnancy and after delivery is functionally related to f luctuations in endogenous brain concentrations of AP whose rate of synthesis͞metabolism appears to differ in the brain, compared with plasma, in pregnant rats.An important feature of ␥-aminobutyric acid type A (GABA A ) receptors in rat brain is their plasticity in response to exposure to brief or long-lasting physiological stimuli or to long-term pharmacological treatments. The kinetic characteristics of the various binding sites located on the GABA A receptor, as well as the density and function of these receptors in different areas of the rat brain, are affected by acute stressful stimuli (handling, foot shock, swimming), postnatal development, aging, kindling, and long-term administration of anxiolytic, hypnotic, or anticonvulsant drugs (1-6). Although recent studies have suggested that some of these changes may be mediated at the level of expression of receptor subunit genes (7-10), the chemical or molecular events that underlie such rapid, shortterm, or persistent changes in the density and affinity of binding sites associated with GABA A receptors, as well as in the function of the receptor complex, remain to be characterized.Neurosteroids accumulate in the mammalian brain in a manner that is, at least in part, independent of the peripheral tissues (adrenal glands and gonads) that synthesize these compounds (11). Systemic administration of progesterone or its metabolites 3␣-hydroxy-5␣-pregnan-20-one (allopregnanolone, AP) and 3␣,21-dihydroxy-5␣-pregnan-20-one (allotetrahydrodeoxycorticosterone, THDOC) induces an...

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Lysozyme is a ~14 kDa protein present in many mucosal secretions (tears, saliva, and mucus) and tissues of animals and plants, and plays an important role in the innate immunity, providing protection against bacteria, viruses, and fungi. Three main different types of lysozymes are known: the c-type (chicken or conventional type), the g-type (goose type), and the i-type (invertebrate type). It has long been the subject of several applications due to its antimicrobial properties. The problem of antibiotic resistance has stimulated the search for new molecules or new applications of known compounds. The use of lysozyme as an alternative antibiotic is the subject of this review, which covers the results published over the past two decades. This review is focused on the applications of lysozyme in medicine, (the treatment of infectious diseases, wound healing, and anti-biofilm), veterinary, feed, food preservation, and crop protection. It is available from a wide range of sources, in addition to the well-known chicken egg white, and its synergism with other compounds, endowed with antimicrobial activity, are also summarized. An overview of the modified lysozyme applications is provided in the form of tables.

Transferrins constitute the most important iron regulation system in vertebrates and some invertebrates. Soluble transferrins, such as bovine lactoferrin and hen egg white ovotransferrin, are glycoproteins with a very similar structure with lobes that complex with iron. In this in vitro study, a comparison of bovine lactoferrin and ovotransferrin was undertaken to confirm the comparability of biological effects. An in vitro gastric barrier model using gastric epithelial cells GTL-16 and an in vitro intestinal barrier model using CaCo-2 cells was employed to evaluate iron absorption and barrier integrity. An analysis of the molecular pathways involving DMT-1 (divalent metal transporter 1), ferritin and ferroportin was also carried out. These in vitro data demonstrate the activity of both 15% saturated and 100% saturated ovotransferrin on the iron regulation system. Compared with the commercial bovine lactoferrin, both 15% saturated and 100% saturated ovotransferrin were found to act in a more physiological manner. Based on these data, it is possible to hypothesise that ovotransferrin may be an excellent candidate for iron supplementation in humans; in particular, 15% saturated ovotransferrin is the overall best performing product. In vivo studies should be performed to confirm this in vitro data.

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Baker's yeast reduction of 1 -(4-methoxyphenyl)propan-2-one, 4-phenylbutan-2-one, and 2-hydroxy-1 -(4-methoxypheny1)ethanone (p-methoxyphenacyl alcohol), afforded in good yield and high optical purity the corresponding (S) -alcohols and the (R)-diol, but only after careful investigation of incubation conditions. Protection of the above hydroxy compounds, and ruthenium tetraoxide oxidation of their acetates, afforded the corresponding acetoxy acids in good yield and high optical purity. ( S ) -I -