Glycomic analysis of human mast cells, eosinophils and basophils

In allergic diseases such as asthma, eosinophils, basophils and mast cells, through release of preformed and newly generated mediators, granule proteins and cytokines, are recognized as key effector cells. While their surface protein phenotypes, mediator release profiles, ontogeny, cell trafficking and genomes have been generally explored and compared, there has yet to be any thorough analysis and comparison of their glycomes. Such studies are critical to understand the contribution of carbohydrates to the induction and regulation of allergic inflammatory responses and are now possible using improved technologies for detecting and characterizing cell-derived glycans. We thus report here the application of high-sensitivity mass spectrometric-based glycomics methodologies to the analysis of N-linked glycans derived from isolated populations of human mast cells, eosinophils and basophils. The samples were subjected to matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) screening analyses and MALDI-TOF/TOF sequencing studies. Results reveal substantive quantities of terminal N-acetylglucosamine containing structures in both the eosinophil and the basophil samples, whereas mast cells display greater relative quantities of sialylated terminal epitopes. For the first time, we characterize the cell surface glycan structures of principal allergic effector cells, which by interaction with glycan-binding proteins (e.g. lectins) have the possibility to dictate cellular functions, and might thus have important implications for the pathogenesis of inflammatory and allergic diseases.

The Amplifier - v. 4, no. 4

In this issue...Dean D. C. McAuliffe, Chelation, Copper Guards, March of Dimes, Ski Club, Coach Simonich, Sigma Rho, Anderson-Carlisle Society, Mineral Club

Biomarkers of the involvement of mast cells, basophils and eosinophils in asthma and allergic diseases.

Biomarkers of disease activity have come into wide use in the study of mechanisms of human disease and in clinical medicine to both diagnose and predict disease course; as well as to monitor response to therapeutic intervention. Here we review biomarkers of the involvement of mast cells, basophils, and eosinophils in human allergic inflammation. Included are surface markers of cell activation as well as specific products of these inflammatory cells that implicate specific cell types in the inflammatory process and are of possible value in clinical research as well as within decisions made in the practice of allergy-immunology.

Zu Berachot 1,1

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Evaluation of the LBJ Hospital Ask Your Nurse Advice Line

This retrospective, case-control study investigated the effectiveness of the Houston, Texas Ask Your Nurse Advice Line (AYN) in diverting callers with non-emergent medical conditions away from the emergency department (ED). After asking callers a series of questions, AYN nurses evaluate the medical condition and make recommendations for appropriate care, e.g., home care, see a clinic physician, or visit the ED. To evaluate the AYN, the rate of caller ED visits before accessing the AYN for the first time was compared to the caller ED visit rate afterwards. The pre-post rate change was compared to that of a control group of similar caller age, race, gender, and insurance status drawn from a Harris County Hospital District HCHD database. ^ The treatment group (AYN caller) had a 66% reduction in ED visits after the first AYN call compared to an 18% drop in ED visits among control group subjects during the same time period. Study results were presented to HCHD staff on August 30th, 2007 and recommendations were made for future studies that would provide a basis for policy development. ^

Modern and fossil corals from Palmyra and Christmas islands

The relationship between decadal to centennial changes in ocean circulation and climate is difficult to discern using the sparse and discontinuous instrumental record of climate and, as such, represents a large uncertainty in coupled ocean-atmosphere general circulation models. We present new modern and fossil coral radiocarbon (D14C) records from Palmyra (6°N, 162°W) and Christmas (2°N, 157°W) islands to constrain central tropical Pacific ocean circulation changes during the last millennium. Seasonally to annually resolved coral D14C measurements from the 10th, 12th-17th, and 20th centuries do not contain significant interannual to decadal-scale variations, despite large changes in coral d18O on these timescales. A centennial-scale increase in coral radiocarbon from the Medieval Climate Anomaly (~900-1200 AD) to the Little Ice Age (~1500-1800) can be largely explained by changes in the atmospheric D14C, as determined with a box model of Palmyra mixed layer D14C. However, large 12th century depletions in Palmyra coral D14C may reflect as much as a 100% increase in upwelling rates and/or a significant decrease in the D14C of higher-latitude source waters reaching the equatorial Pacific during this time. SEM photos reveal evidence for minor dissolution and addition of secondary aragonite in the fossil corals, but our results suggest that coral D14C is only compromised after moderate to severe diagenesis for these relatively young fossil corals.

Stable isotope record of benthic and planktonic foraminifera in sediment cores of ODP Leg 177, Southern Ocean

While onboard ship during Leg 177, we used variations in sediment physical properties (mainly percent color reflectance) in conjunction with biomagnetostratigraphy to correlate among sites and predict the position of marine isotope stages (MISs) (e.g., see fig. F11 in Shipboard Scientific Party, 1999, p. 45). Our working assumption was that physical properties of Leg 177 sediments are controlled mainly by variations in carbonate content. Previous studies of Southern Ocean sediment cores have shown that carbonate concentrations are relatively high during interglacial stages and low during glacial stages at sites located within the Polar Frontal Zone (PFZ). Today, the PFZ marks a lithologic boundary in underlying sediment separating calcareous oozes to the north and silica-rich facies to the south (Hays et al., 1976). Although there is debate whether the position of the "physical" PFZ actually moved during glacial-interglacial cycles (Charles and Fairbanks, 1990; Matsumoto et al., 2001), the "biochemical" PFZ, as expressed by the CaCO3/opal boundary in sediments, certainly migrated north during glacials and south during interglacials. This gave rise to lithologic variations that are useful for stratigraphic correlation. At Leg 177 sites located north of the PFZ and at sublysoclinal depths, we expected the same pattern of carbonate variation because cores in the Atlantic basin are marked by increased carbonate dissolution during glacial periods and increased preservation during interglacials (Crowley, 1985).

Age determination and stable isotope ratios of sediment core RC11-83

The Southern Ocean is perhaps the only region where fluctuations in the global influence of North Atlantic Deep Water (NADW) can be monitored unambiguously in single deep-sea cores. A carbon isotope record from benthic foraminifera in a Southern Ocean core reveals large and rapid changes in the flux of NADW during the last deglaciation, and an abrupt increase in the NADW production rate which immediately preceded large-scale melting of the Northern Hemisphere ice sheets. This sudden strengthening of the NADW thermoha-line cell provides strong evidence for the importance of NADW in glacial-interglacial climate change.