The analysis of alphaâ 1â antitrypsin glycosylation with direct LCâ MS/MS

A liquid chromatographyâ tandem mass spectrometry (LCâ MS/MS)â based methodology has been developed to differentiate coreâ and antennaryâ fucosylated glycosylation of glycopeptides. Both the glycosylation sites (heterogeneity) and multiple possible glycan occupancy at each site (microheterogeneity) can be resolved via intact glycopeptide analysis. The serum glycoprotein alphaâ 1â antitrypsin (A1AT) which contains both coreâ and antennaryâ fucosylated glycosites was used in this study. Sialidase was used to remove the sialic acids in order to simplify the glycosylation microheterogeneity and to enhance the MS signal of glycopeptides with similar glycan structures. β1â 3,4 galactosidase was used to differentiate coreâ and antennaryâ fucosylation. Inâ source dissociation was found to severely affect the identification and quantification of glycopeptides with low abundance glycan modification. The settings of the mass spectrometer were therefore optimized to minimize the inâ source dissociation. A threeâ step mass spectrometry fragmentation strategy was used for glycopeptide identification, facilitated by pGlyco software annotation and manual checking. The collision energy used for initial glycopeptide fragmentation was found to be crucial for improved detection of oxonium ions and better selection of Y1 ion (peptide+GlcNAc). Structural assignments revealed that all three glycosylation sites of A1AT glycopeptides contain complex Nâ glycan structures: site Asn70 contains biantennary glycans without fucosylation; site Asn107 contains biâ , triâ and tetraâ antennary glycans with both coreâ and antennaryâ fucosylation; site Asn271 contains biâ and triâ antennary glycans with both coreâ and antennaryâ fucosylation. The relative intensity of coreâ and antennaryâ fucosylation on Asn107 was similar to that of the A1AT protein indicating that the glycosylation level of Asn107 is much larger than the other two sites.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146302/1/elps6432_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146302/2/elps6432.pd

Quantification of airway thickness changes in smoke-inhalation injury using in-vivo 3-D endoscopic frequency-domain optical coherence tomography

Smoke inhalation injury is frequently accompanied by cyanide poisoning that may result in substantial morbidity and mortality, and methods are needed to quantitatively determine extent of airway injury. We utilized a 3-D endoscopic frequency-domain optical coherence tomography (FD-OCT) constructed with a swept-source laser to investigate morphological airway changes following smoke and cyanide exposure in rabbits. The thickness of the mucosal area between the epithelium and cartilage in the airway was measured and quantified. 3-D endoscopic FD-OCT was able to detect significant increases in the thickness of the tracheal walls of the rabbit beginning almost immediately after smoke inhalation injuries which were similar to those with combined smoke and cyanide poisoning

An Analysis on the Heat Resistance of Rice Germplasm Resources during Flowering Period

56 Chinese rice core germplasm resources, 18 foreign rice germplasm resources and 6 restorer lines are subjected to high temperature stress during flowering period. Based on relative spikelet fertility rate, rice heat resistance is evaluated. The results show that different resistance to high temperature exists in different varieties, and 6 new rice varieties present high heat resistance

High-resolution coregistered intravascular imaging with integrated ultrasound and optical coherence tomography probe.

We report an integrated ultrasound (US) and optical coherence tomography (OCT) probe and system for intravascular imaging. The dual-function probe is based on a 50 MHz focused ring US transducer, with a centric hole for mounting OCT probe. The coaxial US and light beams are steered by a 45° mirror to enable coregistered US∕OCT imaging simultaneously. Lateral resolution of US is improved due to focused ultrasonic beam. Mirror effects on US were investigated and invitro imaging of a rabbit aorta has been carried out. The combined US-OCT system demonstrated high resolution in visualizing superficial arterial structures while retaining deep penetration of ultrasonic imaging

High-resolution coregistered intravascular imaging with integrated ultrasound and optical coherence tomography probe

We report an integrated ultrasound (US) and optical coherence tomography (OCT) probe and system for intravascular imaging. The dual-function probe is based on a 50 MHz focused ring US transducer, with a centric hole for mounting OCT probe. The coaxial US and light beams are steered by a 45° mirror to enable coregistered US∕OCT imaging simultaneously. Lateral resolution of US is improved due to focused ultrasonic beam. Mirror effects on US were investigated and invitro imaging of a rabbit aorta has been carried out. The combined US-OCT system demonstrated high resolution in visualizing superficial arterial structures while retaining deep penetration of ultrasonic imaging

Fabrication of taxifolin loaded zein-caseinate nanoparticles and its bioavailability in rat

Taxifolin loaded zein-caseinate nanoparticles (TZP) were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat. The formulations of TZP were optimized. With mass ratio of 1:1:2 between taxifolin, zein and sodium caseinate, the particle size and ζ-potential of TZP were (168.74 ± 0.35) nm and (−57.67 ± 0.25) mV, while the encapsulation and loading efficiency of taxifolin were (85.83 ± 0.89)% and (17.11 ± 0.88)%, respectively. After freeze-drying, TZP exhibited excellent redispersibility in water without aggregation. Physicochemical characterization showed that taxifolin existed in amorphous form in TZP and its interaction with the protein was observed. After encapsulating in TZP, the excellent dispersion of taxifolin in water significantly improve its diffusion velocity through a semi-permeable membrane. After oral administration, taxifolin and its five metabolites were identified in rat plasma by ultra high performance liquid chromatography (UPLC) with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). The dynamic variation of taxifolin and its metabolites in plasma were then quantified by UPLC with a triple-quadrupole typemass spectroscopy (UPLC-QqQ-MS/MS). A pharmacokinetic study showed that the bioavailability of taxifolin increased from 0.35 % to 0.52 % through TZP fabrication. The plasma concentration of taxifolin glucuronide and methylated taxifolin glucuronide was much higher than taxifolin. Glucuronidation was the dominating metabolism pathway of taxifolin in vivo

Design, Synthesis and Bioactivity Evaluation of Coumarin–BMT Hybrids as New Acetylcholinesterase Inhibitors

Coumarin possesses the aromatic group and showed plentiful activities, such as antioxidant, preventing asthma and antisepsis. In addition, coumarin derivatives usually possess good solubility, low cytotoxicity and excellent cell permeability. In our study, we synthesized the compound bridge methylene tacrine (BMT), which has the classical pharmacophore structure of Tacrine (THA). Based on the principle of active substructure splicing, BMT was used as a lead compound and synthesized coumarin–BMT hybrids by introducing coumarin to BMT. In this work, 21 novel hybrids of BMT and coumarin were synthesized and evaluated for their inhibitory activity on AChE. All obtained compounds present preferable inhibition. Compound 8b was the most active compound, with the value of Ki as 49.2 nM, which was higher than Galantamine (GAL) and lower than THA. The result of molecular docking showed that the highest binding free energy was −40.43 kcal/mol for compound 8b, which was an identical trend with the calculated Ki