Stabilization of branched oligosaccharides: Lewis(x) benefits from a nonconventional C-H···O hydrogen bond.

Although animal lectins usually show a high degree of specificity for glycan structures, their single-site binding affinities are typically weak, a drawback which is often compensated in biological systems by an oligovalent presentation of carbohydrate epitopes. For the design of monovalent glycomimetics, structural information regarding solution and bound conformation of the carbohydrate lead represents a valuable starting point. In this paper, we focus on the conformation of the trisaccharide Le(x) (Gal[Fucα(1-3)]β(1-4)GlcNAc).

Enhanced thermic effect of food after Roux-en-Y gastric bypass surgery.

Context: The mechanisms of weight loss after Roux-en-Y gastric bypass (RYGB) surgery are incompletely understood.

Objective: Our objective was to investigate changes in metabolic processing of ingested food that may contribute to the weight-reducing effect of RYGB surgery.

Design And Setting: This was a cross-sectional case-control study at the Interdisciplinary Obesity Center, Cantonal Hospital St.

Nanomolar E-selectin antagonists with prolonged half-lives by a fragment-based approach.

Selectins, a family of C-type lectins, play a key role in inflammatory diseases (e.g., asthma and arthritis).

Altered brain activity in severely obese women may recover after Roux-en Y gastric bypass surgery.

Objective: Neuroimaging studies have demonstrated alterations in brain activity in obese (OB) subjects that might be causally linked to their disorder. Roux-en Y gastric bypass (RYGB) surgery induces a marked and sustained weight loss and may affect brain activity. The aim of this study was to compare brain activity pattern between severely OB women (n=11), normal-weight women (NW, n=11) and previously severely OB women who had undergone RYGB surgery (RYGB, n=9) on average 3.

Toxicity testing of freshwater sediment collected near freshwater aquaculture facilities in the Maritimes, Canada.

In the Atlantic region of Canada, there are close to 50 land-based freshwater aquaculture facilities, most of which discharge wastewater to freshwater receiving environments. This study was designed to assess the chemical and toxicological characteristics of sediments in those receiving environments. Thirty sediment samples were collected from 3 locations (upstream, outfall and downstream) at seven freshwater aquaculture facilities.

Chemical development of intracellular protein heterodimerizers.

Cell activation initiated by receptor ligands or oncogenes triggers complex and convoluted intracellular signaling. Techniques initiating signals at defined starting points and cellular locations are attractive to elucidate the output of selected pathways. Here, we present the development and validation of a protein heterodimerization system based on small molecules cross-linking fusion proteins derived from HaloTags and SNAP-tags.

Gastric Helicobacter pylori infection is associated with adverse metabolic traits in severely obese subjects.

Objective: Asian studies have reported on an association of Helicobacter pylori (Hp) infection with insulin resistance (IR) in normal-weight subjects. Whether such an association likewise exists in European subjects with severe obesity was questioned.

Design And Methods: To address this question, 370 severely obese patients from our database were identified, who had undergone a gastroscopy with a histological examination of gastric mucosal biopsies and a concurrent assessment metabolic blood parameters as a standard examination before bariatric surgery.

Preoperative nutritional deficiencies in severely obese bariatric candidates are not linked to gastric Helicobacter pylori infection.

Severely obese subjects have been found to show a high prevalence of distinct nutritional deficiencies even without any bariatric intervention but the underlying reasons remain obscure. We tested the hypothesis that gastric Helicobacter pylori infection is associated with increased nutritional deficiency rates. Taking advantage of our large database, we identified 404 patients who had undergone a gastroscopy--as a standard diagnostic assessment before bariatric surgery--along with a histological examination of gastric mucosal biopsies with concurrent nutritional blood measurements.

A molecular-modeling toolbox aimed at bridging the gap between medicinal chemistry and computational sciences.

In the current era of high-throughput drug discovery and development, molecular modeling has become an indispensable tool for identifying, optimizing and prioritizing small-molecule drug candidates. The required background in computational chemistry and the knowledge of how to handle the complex underlying protocols, however, might keep medicinal chemists from routinely using in silico technologies. Our objective is to encourage those researchers to exploit existing modeling technologies more frequently through easy-to-use graphical user interfaces.

Biogeography and historical demography of the Juan Fernandez Rock Lobster, Jasus frontalis (Milne Edwards, 1837).

The genetic structure of present-day populations has been highly affected by glacial periods and physical oceanographic forcing, particularly with respect to species distributions and population gene-flow patterns. We assessed the current genetic composition of the Jasus frontalis population in the southeastern Pacific Islands off the coast of Chile to evaluate their connectivity modulated by contemporary and historic oceanographic processes. Population structure and demographical history for this species were assessed based on classic and Bayesian approaches using 84 sequences of cytochrome oxidase subunit I.

Nanocavity-based determination of absolute values of photoluminescence quantum yields.

We present a new method for determining absolute values of quantum yield of luminescent emitters, which is based on the modification of the radiative transition of emitters within a tunable metallic nanocavity. The method presented is easy to set up and works without any calibration. It will thus be useful for all applications where absolute and calibration-free measurements of luminescence quantum yields are needed.

Reduced circulating androgen levels after gastric bypass surgery in severely obese women.

Background: Previous studies have shown a reduction of elevated androgen levels in premenopausal women after marked weight loss induced by bariatric surgery. In this study, we aimed to assess whether circulating androgen levels also decline after bariatric surgery in women displaying normal values preoperatively as well as in postmenopausal women.

Methods: In 36 severely obese women (six postmenopausal), levels of total testosterone, dehydroepiandresterone sulfate (DHEA-S), and sex hormone-binding globulin (SHBG) were assessed before and at ~1 year after gastric bypass.

Alpine drug discovery summit: 10th Swiss Course on Medicinal Chemistry.

Alpine fresh! Aimed at instructing young scientists at the beginning of their careers in industry, this medicinal chemistry course provides an overview of the state of the art techniques and current approaches to drug discovery and development.

The hedonic drive to consume palatable foods appears to be lower in gastric band carriers than in severely obese patients who have not undergone a bariatric surgery.

Background: We have recently shown that severely obese patients display a markedly enhanced drive to consume palatable food, and that this hedonic hunger is reduced after gastric bypass surgery. Adjustable gastric banding is another frequently performed bariatric operation with unknown effects on hedonic hunger motivation. Here, we compared the level of hedonic hunger in patients who have undergone a gastric banding with that in severely obese patients who have not undergone a bariatric operation and nonobese controls.

Experimental measure of retinal impact force resulting from intraocular foreign body dropped onto retina through media of differing viscosity.

Background: To evaluate and compare the perfluorocarbon liquid, silicone oil, and viscoelastic against standard saline, in their ability to dampen the impact force of a foreign body, dropped within the eye. In an experimental surgical model in where cohesive and adhesive forces of the substances are not enough to float heavy-than-water foreign bodies.

Methods: A model of ophthalmic surgery was constructed.

Differential changes in exercise performance after massive weight loss induced by bariatric surgery.

Background: Exercise performance and pulmonary function are often impaired in severely obese subjects. Bariatric surgery represents the most effective therapy for severe obesity, but data on changes in exercise performance after massive weight loss induced by bariatric surgery have rarely been assessed so far.

Methods: Exercise performance was obtained by bicycle spiroergometry in 18 severely obese patients before and at least 1 year after bariatric surgery.

Target Selectivity of FimH Antagonists.

Mannose-based FimH antagonists are considered new therapeutics for the treatment of urinary tract infections (UTIs). They prevent the adhesion of uropathogenic Escherichia coli (UPEC) to urothelial cell surfaces triggered by the lectin FimH, which is located at the tip of bacterial type 1 pili. Because all reported FimH antagonists are α-d-mannosides, they are also potential ligands of mannose receptors of the human host system.

Roux-en Y gastric bypass surgery reduces hedonic hunger and improves dietary habits in severely obese subjects.

Background: Many obese subjects suffer from an increased hedonic drive to consume palatable foods, i.e., hedonic hunger, and often show unfavorable dietary habits.

Pesticide application and detection in variable agricultural intensity watersheds and their river systems in the maritime region of Canada.

Applications of pesticides in areas of agricultural production have been an environmental concern for the past several decades. Varying-sized watersheds draining regions of intense agriculture in the Maritime Provinces of Canada were monitored between 2003 and 2007 to determine the major in-use pesticides and to gain an understanding of the risks posed to aquatic ecosystems. A questionnaire collected from farmers in one watershed intensively cropped with potato indicated that 43 pesticides were applied with 18 of them being detected in that watershed.

Ionic-liquid-based MS probes for the chemo-enzymatic synthesis of oligosaccharides.

A new N-benzenesulfonyl-based ionic-liquid mass spectroscopy label (I-Tag2) for covalent attachment to substrates has been prepared. I-Tag2 was used to monitor oligosaccharide elongation and serve as a purification handle. Starting from chemically synthesized I-Tag2-labelled N-acetyl glucosamine (GlcNAc) 1, I-Tag2-LacNAc (Galβ(1-4)GlcNAc) 2 and I-Tag2-Lewis(X) (Galβ(1-4)[Fucα(1-3)]GlcNAc) 3, which are oligosaccharides of biological relevance, were enzymatically prepared.

A novel distal very long Roux-en Y gastric bypass (DVLRYGB) as a primary bariatric procedure--complication rates, weight loss, and nutritional/metabolic changes in the first 355 patients.

Proximal Roux-en Y gastric bypass (RYGB) representing the most frequently performed bariatric procedure yields a weight loss failure rate of around 20 %. In order to reduce failure rates, we established a novel distal RYGB variant characterized by a very long alimentary (Roux) limb and a short common channel. Up to 5 years, follow-up data (complication rates, weight loss, nutritional/metabolic changes) of the first 355 patients (mean ± SD preoperative age, 41.

Sialyl Lewis(x): a "pre-organized water oligomer"?

Organized and released: Sialyl Lewis(x) (sLe(x)) represents a "pre-organized water oligomer", that is, a surrogate for clustered water molecules attached to a scaffold. The impetus for sLe(x) binding to E-selectin is shown to be the high degree of pre-organization allowing an array of directed hydrogen bonds, and the entropic benefit of the release of water molecules from the large binding interface to bulk water (see picture).

Characterizing permeability and stability of microcapsules for controlled drug delivery by dynamic NMR microscopy.

Microscopic capsules made from polysaccharides are used as carriers for drugs and food additives. Here, we use NMR microscopy to assess the permeability of capsule membranes and their stability under different environmental conditions. The results allow us to determine the suitability of different capsules for controlled drug delivery.

23-gauge vitrectomy for retained lens material.

A technique for removal of retained lens material is described with a three-port 23-gauge vitrectomy system. Removal of the core vitreous is first performed, followed by removal of the cortical vitreous. All vitreous adhesions to the lens are cleared.