Aligned Fingolimod-Releasing Electrospun Fibers Increase Dorsal Root Ganglia Neurite Extension and Decrease Schwann Cell Expression of Promyelinating Factors.

Researchers are investigating the use of biomaterials with aligned guidance cues, like those provided by aligned electrospun fibers, to facilitate axonal growth across critical-length peripheral nerve defects. To enhance the regenerative outcomes further, these aligned fibers can be designed to provide local, sustained release of therapeutics. The drug fingolimod improved peripheral nerve regeneration in preclinical rodent models by stimulating a pro-regenerative Schwann cell phenotype and axonal growth.

Exposure of Juncus effusus to seven perfluoroalkyl acids: Uptake, accumulation and phytotoxicity.

The extensive use of poly- and perfluoroalkyl substances (PFAS) has led to perfluoroalkyl acids (PFAAs) contamination in various environmental matrices. To remove PFAAs from contaminated water, this study investigated plant uptake of PFAAs by a native wetland plant species in the US, Juncus effusus. The results showed that J.

Production of pyranoanthocyanins using Escherichia coli co-cultures.

Hydroxyphenyl-pyranoanthocyanins are one of the pyranoanthocyanins found in red wines and some fruit juices. Since they have a fourth ring (pyran or ring D) which provides higher color intensity and exceptional stability toward pH variations in comparison to their anthocyanin precursors, these molecules are one of the most important candidates as natural colorants especially for low- and medium-acidic food and beverages. However, their isolation and characterization are difficult due to their very low concentration.

Hydrogen sulfide inhibits amyloid formation.

Amyloid fibrils are large aggregates of misfolded proteins, which are often associated with various neurodegenerative diseases such as Alzheimer's, Parkinson's, Huntington's, and vascular dementia. The amount of hydrogen sulfide (H2S) is known to be significantly reduced in the brain tissue of people diagnosed with Alzheimer's disease relative to that of healthy individuals. These findings prompted us to investigate the effects of H2S on the formation of amyloids in vitro using a model fibrillogenic protein hen egg white lysozyme (HEWL).

The detection of nicotine in a Late Mayan period flask by gas chromatography and liquid chromatography mass spectrometry methods.

Several ancient Mayan vessels from the Kislak Collection of the US Library of Congress were examined for the presence of alkaloids. One of them, a codex-style flask, bears a text that appears to read yo-'OTOT-ti 'u-MAY, spelling y-otoot 'u-may 'the home of its/his/her tobacco'. Samples extracted from this Late Classic period (600 to 900 AD) container were analyzed by gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) methods.

Progress in studies on the RNA world.

The montmorillonite-catalyzed reactions of D, L-ImpA with D, L-ImpU generates RNA-like oligomers. The structures of the dimers to pentamers were investigated and homochiral products were identified in greater amounts than would be expected if theoretical amounts of each were formed. The homochirality increased from 64% to 97% as the chain length increased from dimers to pentamers.

Analysis of E. coli K5 capsular polysaccharide heparosan.

Heparosan is the key precursor for the preparation of bioengineered heparin, a potential replacement for porcine intestinal heparin, an important anticoagulant drug. The molecular weight (MW) distribution of heparosan produced by the fermentation of E. coli K5 was investigated.

Analysis of testosterone and dihydrotestosterone in mouse tissues by liquid chromatography-electrospray ionization-tandem mass spectrometry.

A novel method was established for simultaneous quantitation of testosterone (T) and dihydrotestosterone (DHT) in murine tissue and serum samples. Endogenous T and DHT, together with the internal standards 17alpha-methyl-T and 17alpha-methyl-DHT, were extracted from tissues and then derivatized by reaction with 2-hydrazino-4-(trifluoromethyl)-pyrimidine (HTP). Analysis by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) resulted in product ion spectra of HTP derivatives of both T and DHT that showed analyte-specific fragmentations; the latter fragmentations were characterized by the use of high-resolution Orbitrap MS/MS.

High-resolution preparative separation of glycosaminoglycan oligosaccharides by polyacrylamide gel electrophoresis.

Separation of milligram amounts of heparin oligosaccharides ranging in degree of polymerization from 4 to 32 is achieved within 6h using continuous elution polyacrylamide gel electrophoresis (CE-PAGE) on commercially available equipment. The purity and structural integrity of CE-PAGE-separated oligosaccharides are confirmed by strong anion exchange high-pressure liquid chromatography, electrospray ionization Fourier transform mass spectrometry, and two-dimensional nuclear magnetic resonance spectroscopy. The described method is straightforward and time-efficient, affording size-homogeneous oligosaccharides that can be used in sequencing, protein binding, and other structure-function relationship studies.

ENZYMATIC POLYMERIZATION OF PHENOLS IN ROOM TEMPERATURE IONIC LIQUIDS.

Soybean peroxidase (SBP) was used to catalyze the polymerization of phenols in room-temperature ionic liquids (RTILs). Phenolic polymers with number average molecular weights ranging from 1200 to 4100 D were obtained depending on the composition of the reaction medium and the nature of the phenol. Specifically, SBP was highly active in methylimidazolium-containing RTILs, including 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM(BF(4))), and 1-butyl-3-methylpyridinium tetrafluoroborate (BMPy(BF(4))) with the ionic liquid content as high as 90% (v/v); the balance being aqueous buffer.

Detection of in vivo matrix metalloproteinase activity using microdialysis sampling and liquid chromatography/mass spectrometry.

Matrix metalloproteinases (MMPs) are a family of endoproteases that break down extracellular matrix and whose upregulation contributes to several diseases. A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed to quantify MMP-1 and MMP-9 substrates and their N-terminal peptide products in samples obtained from implanted microdialysis sampling probes. In vitro studies with purified human MMP-1 and MMP-9 were used to optimize the assay and determine the effectiveness of the local delivery of a broad-spectrum MMP inhibitor, GM 6001.

Covalent binding of flavins to RnfG and RnfD in the Rnf complex from Vibrio cholerae.

Enzymes of the Rnf family are believed to be bacterial redox-driven ion pumps, coupling an oxidoreduction process to the translocation of Na+ across the cell membrane. Here we show for the first time that Rnf is a flavoprotein, with FMN covalently bound to threonine-175 in RnfG and a second flavin bound to threonine-187 in RnfD. Rnf subunits D and G are homologous to subunits B and C of Na+-NQR, respectively.

In situ and multisubstrate detection of elastase enzymatic activity external to microdialysis sampling probes using LC-ESI-MS.

Extracellular proteases play significant roles in mammalian development and disease. Enzymatic activity external to a microdialysis sampling probe can be determined by infusing judicious choices of substrates followed by collecting and measuring the products. Porcine pancreatic elastase was used as a model enzyme with two substrates possessing different cleavage sites, N-methoxysuccinyl-Ala-Ala-Pro-Val-7-amino-4-methylcoumarin (FL-substrate) and N-succinyl-Ala-Ala-Ala-p-nitroanilide (UV-substrate).

The first step of hen egg white lysozyme fibrillation, irreversible partial unfolding, is a two-state transition.

Amyloid fibril depositions are associated with many neurodegenerative diseases as well as amyloidosis. The detailed molecular mechanism of fibrillation is still far from complete understanding. In our previous study of in vitro fibrillation of hen egg white lysozyme, an irreversible partially unfolded intermediate was characterized.

Matrix-assisted laser desorption/ionization mass spectrometric analysis of uncomplexed highly sulfated oligosaccharides using ionic liquid matrices.

Direct UV matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analysis of uncomplexed, underivatized, highly sulfated oligosaccharides has been carried out using ionic liquids as matrices. Under conventionally used MALDI time-of-flight experimental conditions, uncomplexed polysulfated oligosaccharides do not produce any signal. We report that 1-methylimidazolium alpha-cyano-4-hydroxycinnamate and butylammonium 2,5-dihydroxybenzoate ionic liquid matrices allow the detection of picomole amounts of the sodium salts of a disaccharide, sucrose octasulfate, and an octasulfated pentasaccharide, Arixtra.

The generation of neutral derivatives of low-valence iron, RFe(I), by netralization-reionization mass spectrometry.

Neutralization-reionization mass spectrometry is applied for the generation of low-valence iron derivatives. Neutralization of Rfe(+) (R=H, F, Cl, Br, I, CN, OH, NH(2), acac, C(6)H(5)) ions resulted in the corresponding neutrals having lifetimes of at least 5 micros. Atom connectivities in RFe ions and neutrals were elucidated by a variety of tandem mass spectrometry techniques.