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Eye
Published in Keith Hopcroft, Vincent Forte, Symptom Sorter, 2020
RARE syphiliscerebromacular degenerationtoxic amblyopia (tobacco, methanol, arsenic, quinine, carbon bisulphide)choroidal melanomaLeber’s hereditary optic atrophy
Organotin Insect Antifeed Ants: An Overview*
Published in Nate F. Cardarelli, Tin as a Vital Nutrient:, 2019
In further studies we found that 0.05% fentin acetate protected potato leaf disks, unfortunately, only at the rate of 70%, against penetration by one larva of the potato tuber moth, Gnorimoschema operculella, per disk.20 The hydroxide was somewhat less active and AC-24,055 practically inactive. Similar results were obtained with leaf disks of eggplant, another host-plant of the potato tuber moth. Results of small-scale field trials in South Africa made evident that with a heavy potato tuber moth infestation, the antifeedant effect of Brestan did not protect the crop, although South African laboratory experiments confirmed ours. We later showed that bis-(fentin) oxide was more active against this insect than fentin acetate and hydroxide, that Brestanol (fentin chloride) and Plictran (cyhexatin; tricyclohexyltin hydroxide) were quite good, and that bis-(fentin) sulfide and bisulfide were inactive.21 Apart from our work with the potato tuber moth, Byrdy et al. from Warsaw investigated the influence of organotins on another potato pest, the Colorado beetle, L. decemlineata.22 They sprayed potato plants growing in containers in glasshouses with 0.1% suspensions of various fentins until runoff. After drying of the residues, L4 Colorado beetle larvae were placed on the plants. The hydroxide, Du-Ter, had the best antifeeding effect, followed by the methyl ether (or methoxyfentin), the acetate, and bis-(fentin) oxide, in that order. One year later the Warsaw group published further results with 0.2% suspensions and found the strongest antifeedant effect for methoxyfentin, fentin benzoate, and fentin acetate.23 With the first two substances the larval weight loss was 22 and 6%, respectively. All three compounds showed clear-cut activity in field trials, but the differences among them did not remain significant in the field. Philips-Duphar experiments also showed potato plants infested with Colorado beetle larvae to be protected from feeding by two Du-Ter sprays (2 weeks apart), and none of the larvae pupated.24
Discovery of novel fragments inhibiting O-acetylserine sulphhydrylase by combining scaffold hopping and ligand–based drug design
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Joana Magalhães, Nina Franko, Giannamaria Annunziato, Martin Welch, Stephen K. Dolan, Agostino Bruno, Andrea Mozzarelli, Stefano Armao, Aigars Jirgensons, Marco Pieroni, Gabriele Costantino, Barbara Campanini
The potency of the compounds was screened at two fixed concentrations (1 μM and 1 mM) by a 96-well plate-adapted activity assay based on the reaction of cysteine with ninhydrin under acidic conditions28,35. The concentration of bisulfide was saturating (600 μM), whereas the concentration of OAS was set at Km to increase the sensitivity. The dissociation constant of selected compounds for StOASS-A and OASS-B was measured by a fluorimetric method published elsewhere23,24. Briefly, a solution containing 1 µM StOASS-A in 100 mM Hepes pH 7 was titrated with increasing concentrations of compound at 20 °C. The fluorescence emission intensity of the PLP cofactor at 505 nm upon excitation at 412 nm was collected after each addition, subtracted by the blank and normalized by the protein dilution. The dependence of the emission intensity at 505 nm on the concentration of the compound was fitted to a binding isotherm23 to calculate the dissociation constant of the protein-ligand complex. As demonstrated elsewhere25,28, the fluorimetric method allows the calculation of the intrinsic dissociation constant of a competitive inhibitor for the enzyme and the calculated Kd is in very good agreement with the IC50 measured by activity assays.
The potential of circulating cell free RNA as a biomarker in cancer
Published in Expert Review of Molecular Diagnostics, 2019
Ka Wan Emily Cheung, Sin-yu Rachel Choi, Lok Ting Claire Lee, Nga Lam Ella Lee, Hin Fung Tsang, Yin Tung Cheng, William Chi Shing Cho, Elaine Yue Ling Wong, Sze Chuen Cesar Wong
Guanidinium-acid-phenol extractions are most commonly used for quick purification of RNA [44–46], which involve the use of RNA lysis buffers with guanidinium thiocyanate or guanidinium hydrochloride (chaotropic agents), leading to separation of RNA with high quality and integrity. Such reagents are potent in protein denaturation and hence, inactivate RNases. The addition of b-mercaptoethanol (b-ME) enhances the action as a reducing agent that breaks the protein intramolecular bisulfide bonds. The isolation of RNA, DNA, and proteins from the acid-phenol extraction is present in the lysate, where the RNAs are precipitated with isopropanol.