Reaction between benzylbromide and sodium cyclopentadienide leads to a mixture of dienes. These can be identified by several techniques such as size exclusion chromatography, mass spectroscopy (MS) ...and high performance liquid chromatography/MS coupling. Their structure is confirmed by analysis of adducts obtained after reaction of
N-(4-benzoyl)-phenylmaleimide with these dienes.
Purified human SHBG was photoaffinity labeled with 17alpha-aminomethyl (M), 17alpha-aminoethyl (E), and 17alpha-aminopropyl (P) derivatives of 3alpha-(3)H-5alpha-androstane-3beta,17beta-diol coupled ...to 5-azido-2-nitrobenzoylamido (ANB), 4-azido-2-nitrophenylamino (ANP), and 5-azido-2-nitro-3,4,6-trifluorophenylamino (ANTFP) chromophores. Successful labeling was achieved in all cases except for the two photoreagents with the shortest side chains, namely, ANP-M and ANTFP-M derivatives. Edman sequencing and mass spectrometry of immunopurified photolabeled tryptic fragments revealed that radioactivity was present either on the sequence of residues 73-94, uniquely at the level of Trp-84 (stable covalent labeling), or on one of the two overlapping sequences of residues 126-134 and 126-135, at the level of Pro-130 (labile labeling) and Lys-134 (either stable or partially labile labeling), respectively. The same Trp-84 was photolabeled with the three ANB derivatives of increasing lengths, and by the ANP-P photoreagent. This residue was the exclusive target for the shortest (3)HANB-M photoreagent but was a minor site for the longest (3)HANB-P photoreagent, essentially recovered at the level of Pro-130. The (3)HANB-E photoreagent of intermediate size also labeled exclusively Trp-84, except in some experiments in which photolabeling was recovered predominantly at the level of Pro-130. The (3)HANP-P photoreagent with an overall length similar to that of the ANB-P photoreagent labeled simultaneously Trp-84 (minor site) and Lys-134. The other (3)HANP-E, (3)HANTFP-E, and (3)HANTFP-P derivatives labeled in all cases Lys-134. These findings indicate that the conserved Trp-84 and the two Pro-130 and Lys-134 residues are all located in the vicinity of the D ring of steroid ligands and remain freely accessible from the C17alpha position, thus providing biochemical data delineating the corresponding region of the steroid-binding site.
The reaction of alpha,alpha'-dibromometaxylene (DBMX) with sodium cyclopentadienide (CpNa) gives several oligomers, which were characterized by Size Exclusion Chromatography (SEC) and Liquid ...Secondary Ion Mass Spectroscopy (LSIMS). The obtained oligomers came from two competitive mechanisms after an anionic substitution of the DBMX by CpNa. The first was based on the proton transfer between the monosubstituted DBMX and CpNa giving a transcient monobrominate carbanion which is the propagating species of a polyanionic substitution. The second one is a classical Diels-Alder reaction between two oligomers containing substituted cyclopentadienes (CPDs) and also between an oligomer and the CPD formed in situ by hydrogen transfer.
Monitoring the homopolymerization of cyanate monomers during heat treatment shows that triazine rings formed during the 180°C step. Oligomers were composed of 1 to 15 triazine rings. Analysis of ...compounds formed before the gel point revealed the presence of side products containing terminal phenolic functions: the phenol-cyanate (M
0
-OH) and oligomers with one or two hydroxyl functions (M
1,2,…
-OH). Kinetic and mechanistic monitoring during treatment at 210°C in the solid state allowed the determination of the structure of the final system and the detection and quantification of unreacted cyanate functions. Kinetic and thermal studies in the temperature range of 100 to 220°C showed that the homopolymerization of hexafluorobisphenol A dicyanate starts at a lower temperature and is slower than that of bisphenol A dicyanate. Thermogravimetric data showed that residual monomers volatilized between 150 and 300°C, while the degradation of crosslinked products occurred between 400 and 600°C and involved two distinct steps.
Purpose To evaluate the correlation between morphologic changes in the outer retina and visual function after successful repair of rhegmatogenous retinal detachment with macula off. Design ...Observational case series. Methods settings: Dijon University Hospital. patients: Thirty patients (30 eyes) with successful repair of rhegmatogenous retinal detachment after macula off and a minimum 6-month follow-up after surgery. main outcome measures: Spectral-domain optical coherence tomography (SD-OCT) of the outer retina, fundus autofluorescence (FAF), and microperimetry. Results Twenty of 30 eyes presented microstructural changes within the photoreceptor layer (66.7%). Of these, half of the patients (50%) had more than 1 lesion. Disrupted inner segment/outer segment (IS/OS) junction was noted in 16 out of 30 eyes (53.3%), irregular hyporeflectivity in the photoreceptor outer segments (PROS) was observed in 17 eyes (56.7%), external limiting membrane was discontinued in 10 eyes (33.3%), and hyperreflective spots in the outer nuclear layer were observed in 5 eyes (16.7%). FAF changes were detected in only 5 eyes (16.7%). Abnormalities in the IS/OS junction were significantly associated with lower foveal and macular sensitivity, thinner PROS, and global photoreceptor changes ( P = .014, P = .003, P = .006, P < .0001, respectively). Patients with a normal foveal profile showed similar findings. Conclusions SD-OCT and microperimetry seem to be appropriate tools to determine the visual and the anatomic recovery of the macula after surgery.
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