Automated solution-phase synthesis of HIV- and Leishmania-associated oligosaccharides to probe structure-dependent immune responses

Infectious disease associated-oligosaccharides are important target molecules for synthesis to enable studies of their functions in infection mechanisms both in humans and animals. Unlike solid-phase automated chemical syntheses of oligonucleotides and oligopeptides that serve to provide these molecules for systematic structure-function relationships, automated chemical synthesis of oligosaccharides has been restricted due to the need to manage stereochemistry of each linkage and to the greater complexity of the monomeric carbohydrate building blocks. A new solution-phase automation platform that relies on fluorous solid-phase extraction (FSPE) to purify intermediates potentially offers easier access to complicated oligosaccharides with several features such as simpler monitoring of reactions, only 2-3 equivalents of building block usage per glycosylation cycle, labor savings, and easier access to previously constructed compounds. In addition, the fluorous allyl-tag used to simplify purification in the automation platform also allows not only direct incorporation into microarrays but also ready modification of the tag for facile conjugation to polymeric vehicles. Herein are reported the development of methods for this automation platform for the first construction of HIV- and Leishmania-associated oligosaccharides. Automated methods to make phosphate-linked sugars as well as conventional glycosidic linkages are demonstrated. Several Leishmania-associated oligosaccharides--including capping structures, phosphate-linked capping structures and phosphoglycan repeats--were synthesized as probes for carbohydrate microarrays to screen sera of infect animals. The further development of efficient conjugation chemistry allowed the multivalent modification of latex beads and degradable micro-/nanoparticles with these bioactive oligosaccharides to probe carbohydrate-related structure/function relationships in the stimulation of cellular immune responses

Newly designed coil tube for bowel decompression in patients with small bowel obstructions

AbstractBackgroundThe purpose of this study was to clinically evaluate a coil tube that we recently designed for bowel decompression in patients with a small bowel obstruction.MethodsThe coil tube was composed of a stainless steel coil, a polyolefin tube, and a rubber adaptor. The tube was inserted under fluoroscopic guidance in 14 consecutive patients with small bowel obstructions. Technical success was defined as insertion of the distal end of the tube into at least the proximal jejunum, and clinical success was defined as intestinal decompression and relief of obstructive symptoms.ResultsThe technical success rate was 100%. Clinical success was achieved in 12 patients (86%). The clinical failures were a patient with peritoneal carcinomatosis and an ileocolic fistula, and a patient with bezoars following intestinal hemorrhage. No coil-related complications occurred.ConclusionOur newly designed coil tube was safe and effective in patients with bowel decompression associated with a small bowel obstruction. In addition, our tube has several advantages over other currently used tube types

The Fingerprint of Climate Change and Urbanization in South Korea

Understanding long-term changes in precipitation and temperature patterns is important in the detection and characterization of climate change, as is understanding the implications of climate change when performing impact assessments. This study uses a statistically robust methodology to quantify long-, medium- and short-term changes for evaluating the degree to which climate change and urbanization have caused temporal changes in precipitation and temperature in South Korea. We sought to identify a fingerprint of changes in precipitation and temperature based on statistically significant differences at multiple-timescales. This study evaluates historical weather data during a 40-year period (1973–2012) and from 54 weather stations. Our results demonstrate that between 1993–2012, minimum and maximum temperature trends in the vicinity of urban and agricultural areas are significantly different from the two previous decades (1973–1992). The results for precipitation amounts show significant differences in urban areas. These results indicate that the climate in urbanized areas has been affected by both the heat island effect and global warming-caused climate change. The increase in the number of rainfall events in agricultural areas is highly significant, although the temporal trends for precipitation amounts showed no significant differences. Overall, the impacts of climate change and urbanization in South Korea have not been continuous over time and have been expressed locally and regionally in terms of precipitation and temperature changes

Protective Effect of Heme Oxygenase-1 on High Glucose-Induced Pancreatic β-Cell Injury

BackgroundGlucose toxicity that is caused by chronic exposure to a high glucose concentration leads to islet dysfunction and induces apoptosis in pancreatic β-cells. Heme oxygenase-1 (HO-1) has been identified as an anti-apoptotic and cytoprotective gene. The purpose of this study is to investigate whether HO-1 up-regulation when using metalloprotophyrin (cobalt protoporphyrin, CoPP) could protect pancreatic β-cells from high glucose-induced apoptosis.MethodsReverse transcription-polymerase chain reaction was performed to analyze the CoPP-induced mRNA expression of HO-1. Cell viability of INS-1 cells cultured in the presence of CoPP was examined by acridine orange/propidium iodide staining. The generation of intracellular reactive oxygen species (ROS) was measured using flow cytometry. Glucose stimulated insulin secretion (GSIS) was determined following incubation with CoPP in different glucose concentrations.ResultsCoPP increased HO-1 mRNA expression in both a dose- and time-dependent manner. Overexpression of HO-1 inhibited caspase-3, and the number of dead cells in the presence of CoPP was significantly decreased when exposed to high glucose conditions (HG). CoPP also decreased the generation of intracellular ROS by 50% during 72 hours of culture with HG. However, decreased GSIS was not recovered even in the presence of CoPP.ConclusionOur data suggest that CoPP-induced HO-1 up-regulation results in protection from high glucose-induced apoptosis in INS-1 cells; however, glucose stimulated insulin secretion is not restored