Bone turnover markers in the preoperative assessment of bone quality - A prospective investigation of bone microstructure and advanced glycation endproducts in lumbar fusion patients.

Introduction: Effective tools to evaluate bone quality preoperatively are scarce and the standard method to determine bone quality requires an invasive biopsy. A non-invasive, and preoperatively available method for bone quality assessment would be of clinical value. The purpose of this study is to investigate the associations of bone formation marker, serum bone alkaline phosphatase (BAP), and bone resorption marker, urine collagen cross-linked N-telopeptide (uNTX) to volumetric bone mineral density (vBMD), fluorescent advanced glycation endproducts (fAGEs) and bone microstructure.

Osteosarcopenia in the Spine Beyond Bone Mineral Density: Association Between Paraspinal Muscle Impairment and Advanced Glycation Endproducts.

Study Design: Prospective cross-sectional study.

Objective: To determine if an accumulation of advanced glycation endproducts (AGEs) is associated with impaired paraspinal muscle composition.

Background: Impaired bone integrity and muscle function are described as osteosarcopenia.

Bone collagen quality in lumbar fusion patients: the association between volumetric bone mineral density and advanced glycation endproducts.

Purpose: The sole determination of volumetric bone mineral density (vBMD) is insufficient to evaluate overall bone integrity. The accumulation of advanced glycation endproducts (AGEs) stiffens and embrittles collagen fibers. Despite the important role of AGEs in bone aging, the relationship between AGEs and vBMD is poorly understood.

Dermal ultrasound measurements for bone quality assessment : An investigation of advanced glycation endproducts derived from confocal fluorescence microscopy.

Bone quality is increasingly being recognized in the assessment of fracture risk. Nonenzymatic collagen cross-linking with the accumulation of advanced glycation end products stiffens and embrittles collagen fibers thus increasing bone fragility. Echogenicity is an ultrasound (US) parameter that provides information regarding the skin collagen structure.

Asymmetric Total Synthesis of (-)-Spirochensilide A, Part 1: Diastereoselective Synthesis of the ABCD Ring and Stereoselective Total Synthesis of 13()-Demethyl Spirochensilide A.

A concise and diastereoselective construction of the ABCD ring system of spirochensilide A is described. The key steps of this synthesis are a semipinacol rearrangement reaction to stereoselectively construct the AB ring system bearing two vicinal quaternary chiral centers and a Co-mediated Pauson-Khand reaction to form the spiro-based bicyclic CD ring system. This chemistry leads to the stereoselective synthesis of 13()-demethyl spirochensilide A, paving the way for the first asymmetric total synthesis of (-)-spirochensilide A.

[Inhibition and Remediation of Methylmercury Contaminated Soil by Use of Modified Montmorillonite].

Montmorillonite was modified by 3-mercaptopyl trimethoxysilane and chitosan. The modified montmorillonite was characterized by XRD technology. The effects of thiol montmorillonite and chitosan montmorillonite on the inhibition and remediation of methylmercury contaminated soil under different water conditions were studied using laboratory simulation.

Canscora lucidissima, a Chinese folk medicine, exerts anti-inflammatory activities by inhibiting the phosphorylation of ERK1/2 in LPS-activated macrophages.

Background: Canscora lucidissima (Levl. & Vaniot) Hand.-Mazz.

Asymmetric Total Synthesis of Pre-schisanartanin C.

Pre-schisanartanin C belongs to the family of nortriterpenoids with potent antihepatitis, antitumor, and anti-HIV activities. This paper presents the enantioselective total synthesis of pre-schisanartanin C (). An important step in the total synthesis of is gold-catalyzed intramolecular cyclopropanation of a 1,8-enyne substrate bearing a secondary ester group at the propargylic position to prepare a bicyclo[6.

Asymmetric Total Synthesis of Lancifodilactone G Acetate. 2. Final Phase and Completion of the Total Synthesis.

The asymmetric total synthesis of lancifodilactone G acetate was accomplished in 28 steps. The key steps in this synthesis include (i) an asymmetric Diels-Alder reaction for formation of the scaffold of the BC ring; (ii) an intramolecular ring-closing metathesis reaction for the formation of the trisubstituted cyclooctene using a Hoveyda-Grubbs II catalyst; (iii) an intramolecular Pauson-Khand reaction for construction of the sterically congested F ring; (iv) sequential cross-metathesis, hydrogenation, and lactonization reactions for installation of the anomerically stabilized bis-spiro ketal fragment of lancifodilactone G; and (v) a Dieckmann-type condensation reaction for installation of the A ring. The strategy and chemistry developed for the total synthesis will be useful in the synthesis of other natural products and complex molecules.

Biomimetically inspired asymmetric total synthesis of (+)-19-dehydroxyl arisandilactone A.

Complex natural products are a proven and rich source of disease-modulating drugs and of efficient tools for the study of chemical biology and drug discovery. The architectures of complex natural products are generally considered to represent significant barriers to efficient chemical synthesis. Here we describe a concise and efficient asymmetric synthesis of 19-dehydroxyl arisandilactone A-which belongs to a family of architecturally unique, highly oxygenated nortriterpenoids isolated from the medicinal plant Schisandra arisanensis.