Electroanalysis may be used in the Vanillin Biotechnological Production

This study shows that electroanalysis may be used in vanillin biotechnological production. As a matter of fact, vanillin and some molecules implicated in the process like eugenol, ferulic acid, and vanillic acid may be oxidized on electrodes made of different materials (gold, platinum, glassy carbon). By a judicious choice of the electrochemical method and the experimental conditions the current intensity is directly proportional to the molecule concentrations in a range suitable for the biotechnological process. So, it is possible to imagine some analytical strategies to control some steps in the vanillin biotechnological production: by sampling in the batch reactor during the process, it is possible to determine out of line the concentration of vanillin, eugenol, ferulic acid, and vanillic acid with a gold rotating disk electrode, and low concentration of vanillin with addition of hydrazine at an amalgamated electrode. Two other possibilities consist in the introduction of electrodes directly in the batch during the process; the first one with a gold rotating disk electrode using linear sweep voltammetry and the second one requires three gold rotating disk electrodes held at different potentials for chronoamperometry. The last proposal is the use of ultramicroelectrodes in the case when stirring is not possible

Substrate specificity of guinea pig liver aldehyde oxidase and bovine milk xanthine oxidase for methyl- and nitrobenzaldehydes

Both aidehyde oxidase and xanthine oxidase catalyze the oxidation of a wide range of N-heterocycles and aldehydes. These enzymes are important in the oxidation of N-heterocyclic xenobiotics, whereas their role in the oxidation of xenobiotic aldehydes is usually ignored. The present investigation describes the interaction of methyl- and nitrosubstituted benzaldehydes, in the ortho-, meta- and parapositions, with guinea pig liver aldehyde oxidase and bovine milk xanthine oxidase. The kinetic constants showed that most substituted benzaldehydes are excellent substrates of aldehyde oxidase with lower affinities for xanthine oxidase. Low K-m values for aldehyde oxidase were observed with most benzaldehydes tested, with 3-nitrobenzaldehyde having the lowest K-m value and 3-methylbenzaldehyde being the best substrate in terms of substrate efficiency (K-s). Additionally, low K-m values for xanthine oxidase were found with most benzaldehydes tested. However, all benzaldehydes also had low V-max values, which made them poor substrates of xanthine oxidase. It is therefore possible that aldehyde oxidase may be critical in the oxidation of xenobiotic and endobiotic derived aldehydes and its role in such reactions should not be ignored

Dorycnioside, a New Phenylbutanone Glucoside from Dorycnium pentaphyllum subsp. herbaceum

A new phenylbutanone glucoside, dorycnioside, was isolated from the methanol extract of the aerial parts of Dorycnium pentaphyllum subsp. herbaceum Vill. (Rouy) and identified as 4-(4′-O-β-D-glucopyranosyl-3′, 5′-dimethoxyphenyl)-2-butanone (1). In addition, two known phenylbutanone glucosides, five flavonoids, one cyanogenic glucoside, one cyclitol and one hydroquinone glucoside were also isolated and identified. The major constituent of the methanol extract was found to be myricitrin. The structure of 1 was elucidated on the basis of its spectroscopic data. It is the first time that derivatives of phenylbutanone are isolated from the Leguminosae family

Linezolid: a Promising Agent for the Treatment of Multiple and Extensively Drug-Resistant Tuberculosis

Tuberculosis is a severe, infectious disease caused by Mycobacterium tuberculosis. The aim of this review was to present the efficacy of linezolid as an agent against multidrug and extensively drug-resistant tuberculosis as gathered from many recent research studies. Linezolid seems to have strongly the potential of being used as an anti-tuberculosis agent because it blocks bacterial ribosomal protein synthesis. Nevertheless caution is required because of the adverse effects it causes, especially when the linezolid daily dosage exceeds 600 mg. The most severe adverse effects include anemia, peripheral neuropathy, optic neuropathy and thrombocytopenia. Still, more trials and research need to be done in order to gather more information and value the cost-benefit dosage of the treatment. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Calcium dynamics at the neural cell primary cilium regulate Hedgehog signaling-dependent neurogenesis in the embryonic neural tube.

The balance between neural stem cell proliferation and neuronal differentiation is paramount for the appropriate development of the nervous system. Sonic hedgehog (Shh) is known to sequentially promote cell proliferation and specification of neuronal phenotypes, but the signaling mechanisms responsible for the developmental switch from mitogenic to neurogenic have remained unclear. Here, we show that Shh enhances Ca2+ activity at the neural cell primary cilium of developing Xenopus laevis embryos through Ca2+ influx via transient receptor potential cation channel subfamily C member 3 (TRPC3) and release from intracellular stores in a developmental stage-dependent manner. This ciliary Ca2+ activity in turn antagonizes canonical, proliferative Shh signaling in neural stem cells by down-regulating Sox2 expression and up-regulating expression of neurogenic genes, enabling neuronal differentiation. These discoveries indicate that the Shh-Ca2+-dependent switch in neural cell ciliary signaling triggers the switch in Shh action from canonical-mitogenic to neurogenic. The molecular mechanisms identified in this neurogenic signaling axis are potential targets for the treatment of brain tumors and neurodevelopmental disorders

Noncanonical function of folate through folate receptor 1 during neural tube formation

Abstract Folate supplementation reduces the occurrence of neural tube defects (NTDs), birth defects consisting in the failure of the neural tube to form and close. The mechanisms underlying NTDs and their prevention by folate remain unclear. Here we show that folate receptor 1 (FOLR1) is necessary for the formation of neural tube-like structures in human-cell derived neural organoids. FOLR1 knockdown in neural organoids and in Xenopus laevis embryos leads to NTDs that are rescued by pteroate, a folate precursor that is unable to participate in metabolism. We demonstrate that FOLR1 interacts with and opposes the function of CD2-associated protein, molecule essential for apical endocytosis and turnover of C-cadherin in neural plate cells. In addition, folates increase Ca2+ transient frequency, suggesting that folate and FOLR1 signal intracellularly to regulate neural plate folding. This study identifies a mechanism of action of folate distinct from its vitamin function during neural tube formation

Lower early morning plasma cortisol levels are associated with thyroid autoimmunity in the elderly

Objectives: Thyroid autoimmunity decreases in the very old. We investigated whether glucocorticoid (GC) activity, which increases in old age, is involved in this process. Subjects and methods: A total of 321 ambulatory subjects (age 51-95 years, median 71, 207 female) were studied. Thyroid function tests, cortisol, glucose, insulin and biochemical parameters were measured. A modified overnight dexamethasone suppression test (0.25 mg) was performed as an index of GC sensitivity. Results: Forty subjects had positive anti-thyroid peroxidase antibodies and 36 had positive anti-thyroglobulin antibodies, while 57 had either one or the other or both thyroid autoantibodies (ThAbs) positive. Mean basal cortisol levels were significantly lower in the ThAbs (+) groups (320 +/- 125 vs 378 +/- 128 nmol/l, P=0.002). Triiodothyronine, free thyroxine, post-dexamethasone cortisol levels, C-reactive protein, homeostasis model assessment-insulin-resistance-index and body mass index did not differ between these two groups. Mean age of ThAbs (C) subjects was lower compared to the ThAbs (-) group (67.38 +/- 7.38 vs 71.64 +/- 8.57 years, P=0.001). Conclusions: Reduced GC activity is associated with an increased prevalence of ThAbs positivity in older ambulatory subjects. Subjects without ThAbs in this population sample are relatively older. It is not known whether this is related to increasing GC activity with age