VaporSPOT: Parallel Synthesis of Oligosaccharides on Membranes.

Automated chemical synthesis has revolutionized synthetic access to biopolymers in terms of simplicity and speed. While automated oligosaccharide synthesis has become faster and more versatile, the parallel synthesis of oligosaccharides is not yet possible. Here, a chemical vapor glycosylation strategy (VaporSPOT) is described that enables the simultaneous synthesis of oligosaccharides on a cellulose membrane solid support. Different linkers allow for flexible and straightforward cleavage, purification, and characterization of the target oligosaccharides. This method is the basis for the development of parallel automated glycan synthesis platforms.

Automated Laser-Transfer Synthesis of High-Density Microarrays for Infectious Disease Screening.

Laser-induced forward transfer (LIFT) is a rapid laser-patterning technique for high-throughput combinatorial synthesis directly on glass slides. A lack of automation and precision limits LIFT applications to simple proof-of-concept syntheses of fewer than 100 compounds. Here, an automated synthesis instrument is reported that combines laser transfer and robotics for parallel synthesis in a microarray format with up to 10 000 individual reactions cm- 2 . An optimized pipeline for amide bond formation is the basis for preparing complex peptide microarrays with thousands of different sequences in high yield with high reproducibility. The resulting peptide arrays are of higher quality than commercial peptide arrays. More than 4800 15-residue peptides resembling the entire Ebola virus proteome on a microarray are synthesized to study the antibody response of an Ebola virus infection survivor. Known and unknown epitopes that serve now as a basis for Ebola diagnostic development are identified. The versatility and precision of the synthesizer is demonstrated by in situ synthesis of fluorescent molecules via Schiff base reaction and multi-step patterning of precisely definable amounts of fluorophores. This automated laser transfer synthesis approach opens new avenues for high-throughput chemical synthesis and biological screening.

Probing Multivalent Carbohydrate-Protein Interactions With On-Chip Synthesized Glycopeptides Using Different Functionalized Surfaces.

Multivalent ligand-protein interactions are a commonly employed approach by nature in many biological processes. Single glycan-protein interactions are often weak, but their affinity and specificity can be drastically enhanced by engaging multiple binding sites. Microarray technology allows for quick, parallel screening of such interactions. Yet, current glycan microarray methodologies usually neglect defined multivalent presentation. Our laser-based array technology allows for a flexible, cost-efficient, and rapid in situ chemical synthesis of peptide scaffolds directly on functionalized glass slides. Using copper(I)-catalyzed azide-alkyne cycloaddition, different monomer sugar azides were attached to the scaffolds, resulting in spatially defined multivalent glycopeptides on the solid support. Studying their interaction with several different lectins showed that not only the spatially defined sugar presentation, but also the surface functionalization and wettability, as well as accessibility and flexibility, play an essential role in such interactions. Therefore, different commercially available functionalized glass slides were equipped with a polyethylene glycol (PEG) linker to demonstrate its effect on glycan-lectin interactions. Moreover, different monomer sugar azides with and without an additional PEG-spacer were attached to the peptide scaffold to increase flexibility and thereby improve binding affinity. A variety of fluorescently labeled lectins were probed, indicating that different lectin-glycan pairs require different surface functionalization and spacers for enhanced binding. This approach allows for rapid screening and evaluation of spacing-, density-, ligand and surface-dependent parameters, to find optimal lectin binders.

On-Chip Neo-Glycopeptide Synthesis for Multivalent Glycan Presentation.

Single glycan-protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding.

Multivalent glycan arrays.

Glycan microarrays have become a powerful technology to study biological processes, such as cell-cell interaction, inflammation, and infections. Yet, several challenges, especially in multivalent display, remain. In this introductory lecture we discuss the state-of-the-art glycan microarray technology, with emphasis on novel approaches to access collections of pure glycans and their immobilization on surfaces. Future directions to mimic the natural glycan presentation on an array format, as well as in situ generation of combinatorial glycan collections, are discussed.

The iSCREEN Electronic Diabetes Dashboard: A Tool to Improve Knowledge and Implementation of Pediatric Clinical Practice Guidelines.

OBJECTIVES: Clinical practice guidelines (CPG) provide evidence-based recommendations for patient care but may not be optimally applied in clinical settings. As a pilot study, we evaluated the impact of a computerized, point-of-care decision support system (CDSS) on guideline knowledge and adherence in our diabetes clinic. METHODS: iSCREEN, a CDSS, integrated with a province-wide electronic health record, was designed based on the Canadian Diabetes Association 2013 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada. Evaluation data were gathered by retrospective chart review and clinician questionnaire prior to and after implementation of iSCREEN. Records of patients with type 1 diabetes, 14 to 18 years of age, were assessed for appropriate screening for complications and comorbidities. RESULTS: To assess guideline adherence, 50 charts were reviewed at 2 time periods (25 before and 25 after launch of iSCREEN). Results revealed improved frequency of appropriate screening for diabetic nephropathy (p=0.03) and retinopathy (p=0.04), accompanied by a decrease in under- and overscreening for these outcomes. To assess guideline knowledge, 58 surveys were collected (31 prior to and 27 after the launch of iSCREEN) from care providers in the field of pediatric diabetes. There was a trend toward improved guideline knowledge in all team members (p=0.06). CONCLUSIONS: Implementation of a de novo CDSS was associated with improved rates of appropriate screening for diabetes-related complications. A trend toward improvement in health professionals' knowledge of the guidelines was also observed. Evaluation of this point-of-care computerized decision support tool suggests that it may facilitate diabetes care by optimizing complication screening and CPG knowledge, with the potential for broader implementation.

Celiac Disease Alone and Associated With Type 1 Diabetes Mellitus.

OBJECTIVES: The aim of the study was to evaluate complication screening and follow-up patterns in a population with type 1 diabetes mellitus and celiac disease (T1D/CD) in relation to a matched cohort with celiac disease (CD) alone at our center. METHODS: We retrospectively reviewed the health charts of 41 children with T1D and biopsy-proven CD and compared anthropometrics and complication of screening within 2 years from CD diagnosis. Follow-up patterns were determined 3 years postdiagnosis. This population was then compared with a population with both symptomatic and asymptomatic CD matched for age and sex. RESULTS: In comparison with T1D/CD, patients with CD alone had a significantly lower height, weight and body mass index (BMI z score 0.01 vs 0.81, P = 0.001) and higher rates of screening for anemia (95% vs 71%, P = 0.003) and bone health (49% vs 29%, P = 0.05). Minimal rates of laboratory abnormalities were observed in either group, irrespective of symptoms at presentation, but CD alone more often presented with anemia than T1D/CD. Repeat serology testing was significantly more frequently performed in the T1D/CD group. Follow-up was equally variable with a median of 3 (range 0-4) visits with a gastroenterologist during the first 3 years postdiagnosis. CONCLUSIONS: These results suggest that patients with T1D/CD represent a distinct and possibly milder phenotype from CD alone. Complication screening was variable and negative for the majority of the patients. Guidelines for follow-up may need to be tailored to specific groups to standardize evaluation and complication screening, especially with regard to bone health.

Salivary adiponectin levels are associated with training intensity but not with bone mass or reproductive function in elite Rhythmic Gymnasts.

Elite Rhythmic Gymnasts (RGs) constitute a unique metabolic model and they are prone to developing Anorexia Athletica. The aim of the present study was to evaluate the effect of training intensity on salivary adiponectin levels and assess a possible role of salivary adiponectin levels as a predictive factor of reproductive dysfunction and bone mass acquisition in elite RGs. The study included 80 elite female RGs participating in the World Rhythmic Gymnastics Championship tournament held in Montpellier, France on September 2011. Anthropometric values were assessed, training data and menstrual pattern were recorded, bone mass was measured with Broadband ultrasound attenuation (dB/Mhz) and baseline salivary adiponectin levels were determined. The athletes were classified as intensely and very intensely trained, considering the mean training intensity (40.84h/week). Moreover, considering their reproductive status, they were divided into RG's with normal menstruation, primary amenorrhea and oligomenorrhea. All comparisons were adjusted to age, BMI and body fat percentage differences. Very intensely trained RGs showed higher salivary adiponectin levels (p=0.05). Moreover, salivary adiponectin levels showed significant correlation with training intensity (r=0.409, p=0.003). On the other hand, no association of salivary adiponectin levels was documented with either reproductive function or bone mass acquisition. The results of the present study suggest that, in elite RGs, salivary adiponectin levels are associated with the intensity of training, possibly reflecting the deterioration of energy balance rather than the training stress. On the other hand, a predictive role of salivary adiponectin levels in reproductive dysfunction or bone mass acquisition could not be supported.

Despite a high prevalence of menstrual disorders, bone health is improved at a weight-bearing bone site in world-class female rhythmic gymnasts.

CONTEXT: Regular physical activity during puberty improves bone mass acquisition. However, it is unknown whether extreme intense training has the same favorable effect on the skeleton. OBJECTIVE: We evaluated the bone mass acquisition in a unique cohort of world-class rhythmic gymnasts. STUDY PARTICIPANTS: A total of 133 adolescent girls and young women with a mean age of 18.7 ± 2.7 (14.4-26.7) years participated in this study: 82 elite rhythmic gymnasts (RGs) and 51 controls (CONs). MAIN OUTCOME MEASURES: Anthropometric variables and body composition were assessed, and all participants completed questionnaires on their general medical, menstrual, and training histories. Broadband ultrasound attenuation (BUA in decibels per megahertz) was determined by quantitative ultrasound at the heel. RESULTS: RGs presented lower weight (-8.5%, P < .001), body mass index (-11.7%, P < .001), and body fat mass (-43%, P < .001) and higher muscle mass (6.3%, P < .01) and height (+2.8 cm, P < .01). RGs presented an age of menarche significantly delayed compared with CONs (15.6 ± 1.6 vs 12.7 ± 1.7 years; P < .001) and a high prevalence of menstrual disorders (64%). BUA values were higher in RGs vs CONs (68.6 ± 4.6 and 65.4 ± 3.3 dB/Mhz, respectively; P < .001). This difference was exacerbated when BUA was adjusted for age and body weight. BUA values in RGs were not affected by menstrual or training status. Among RGs with menarche, BUA was higher (71.5 ± 4.1 and 67.9 ± 3.5 dB/Mhz) for delayed (14.4 ± 0.8 years) vs severely delayed (17.3 ± 1.4 years) menarcheal age. BUA was positively correlated with body weight and body mass index and tended to be correlated with age. CONCLUSION: Conversely to expectations for adolescents and young women with a high prevalence of menstrual disorders and/or delayed menarche, intense training in rhythmic gymnastics appeared to have a beneficial effect on the bone health of a weight-bearing site. This effect was nevertheless modulated by the age of menarche. The high mechanical loading generated by this activity may counterbalance the negative effect of menstrual disorders.

Complications of chronic liver disease.

Children with chronic liver disease (CLD) need a head to toe approach and an early suspicion of multi organ involvement. Nutritional assessment and management is the cornerstone of management. Consider immune dysfunction in everyday treatment decisions. Consider early heart-lung-brain involvement in transplant evaluation.