Hemolytic-uremic syndrome is a clinical syndrome characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia that often follows infection by Shiga toxin- or verotoxin-producing strains of Escherichia coli. Because thrombocytopenia and platelet activation are hallmark features of hemolytic-uremic syndrome, we examined the ability of Shiga toxin to bind platelets by flow cytometry and high-performance thin-layer chromatography (HPTLC) of isolated platelet glycosphingolipids. By HPTLC, Shiga toxin was shown to bind globotriaosylceramide (Gb3) and a minor platelet glycolipid with anRf of 0.03, band 0.03. In a survey of 20 human tissues, band 0.03 was identified only in platelets. In individuals, band 0.03 was expressed by 20% of donors and was specifically associated with increased platelet Gb3 expression. Based on glycosidase digestion and epitope mapping, band 0.03 was hypothesized to represent a novel glycosphingolipid, IV3-β-Galα1-4galactosylglobotetraosylceramide. Based on incidence, structure, and association with increased Gb3 expression, band 0.03 may represent the antithetical Luke blood group antigen. By flow cytometry, Shiga toxin bound human platelets, although the amount of Shiga toxin bound varied in donors. Differences in Shiga toxin binding to platelet membranes did not reflect differences in platelet Gb3 expression. In contrast, there was a loose association between Shiga toxin binding and decreasing forward scatter, suggesting that Shiga toxin and verotoxins bind more efficiently to smaller, older platelets. In summary, Shiga and Shiga-like toxins may bind platelets via specific glycosphingolipid receptors. Such binding may contribute to the thrombocytopenia, platelet activation, and microthrombus formation observed in hemolytic-uremic syndrome.

Activated platelets are known to express P-selectin, a lectin-like adhesion receptor (CD62), through which they bind to sialyl Lewis X (sLex) ligands displayed on the membranes of leukocytes. To determine whether direct platelet-platelet interactions via P-selectin/sLex interactions are also possible, we have examined the ganglioside extract of human blood platelets for the presence of sLex ligands. Using the sensitive method of high-performance thin-layer chromatography (HPTLC)-immunostaining with the monoclonal antibody (mAb) CSLEX or with sialidase followed by mAbs MC480 or PM81, eight sLex bands were demonstrated at Rf 0.01, 0.03, 0.05, 0.06, 0.08, 0.10, 0.14 and 0.21 in the solvent 45:55:10 chloroform-methanol-aqueous 0.02% CaCl2. The sensitivity of all eight bands to sialidase or endoglycoceramidase confirmed that they were gangliosides. Comparison of the HPTLC mobilities and densities of platelet bands with those from five other human tissues (granulocytes, monoblasts, kidney, aortic endothelium and erythrocytes) in three different solvents revealed three major bands associated with platelets: 3 (Rf0.03), 6 (0.08) and 14 (0.21). Platelet bands were demonstrated not to have resulted from granulocyte contamination. Partial purification of platelet sLex gangliosides by high-performance liquid chromatography and their reaction with 14 oligosaccharide-specific mAbs (FH4, FH5, LM112-161, LM119-181, A5, 1B2, BR55-2, BE2, ES4, MC631, MH04, SH34, P001 and MC813-70) revealed that band 6 is a multifucosylated neolacto ganglioside and band 14 is a branched, disialo neolacto fucoganglioside. Platelet band 3 combined the features of both bands 6 and 14, and reacted differently than granulocyte band 3. These partial structures resemble gangliosides associated with adhesion in other cell systems. It is concluded that platelets express tissue-specific sLex gangliosides (sLex ligands). Thus, it is possible that platelet-platelet binding may be mediated at least partially through P-selectin/sLex interactions, especially after platelet activation.

Chronic pain, a debilitating medical condition affecting approximately 15% of the US population, leads to individual suffering and costs to society in terms of health care dollars and lost productivity. To examine the effectiveness of a comprehensive pain management program, data from 108 program participants were evaluated. Preprogram, postprogram, and 6-month follow-up data were collected from 80 participants, and preprogram, postprogram, and 1-year data were collected from 46 participants. Outcomes data from several domains were assessed: pain severity, emotional distress, interference of pain on function, perceived control of pain, treatment helpfulness, and number of hours resting. Within-subject repeated-measure analyses of variance found statistically significant findings on the six outcome measures utilized in this study for both the 6-month and 1-year samples. Examination of 95% confidence intervals revealed no overlap in pretreatment scores with 6-month and 1-year outcomes in five of the six domains studied. Mean scores on emotional distress did not maintain statistical significance in the 6-month or 1-year review. Overall, this study strengthens the case for interdisciplinary care for chronic pain management and provides evidence for the long-term effectiveness of this therapy. Furthermore, this study lends support to the notion that interdisciplinary treatments are effective in targeting multiple domains affected by the pain condition.

Hemolytic-uremic syndrome is a clinical syndrome characterized by acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia that often follows infection by Shiga toxin-or verotoxin-producing strains of Escherichia coli. Because thrombocytopenia and platelet activation are hallmark features of hemolytic-uremic syndrome, we examined the ability of Shiga toxin to bind platelets by flow cytometry and highperformance thin-layer chromatography (HPTLC) of isolated platelet glycosphingolipids. By HPTLC, Shiga toxin was shown to bind globotriaosylceramide (Gb 3) and a minor platelet glycolipid with an R f of 0.03, band 0.03. In a survey of 20 human tissues, band 0.03 was identified only in platelets. In individuals, band 0.03 was expressed by 20% of donors and was specifically associated with increased platelet Gb 3 expression. Based on glycosidase digestion and epitope mapping, band 0.03 was hypothesized to represent a novel glycosphingolipid, IV 3-␤-Gal␣1-4galactosylglobotetraosylceramide. Based on incidence, structure, and association with increased Gb 3 expression, band 0.03 may represent the antithetical Luke blood group antigen. By flow cytometry, Shiga toxin bound human platelets, although the amount of Shiga toxin bound varied in donors. Differences in Shiga toxin binding to platelet membranes did not reflect differences in platelet Gb 3 expression. In contrast, there was a loose association between Shiga toxin binding and decreasing forward scatter, suggesting that Shiga toxin and verotoxins bind more efficiently to smaller, older platelets. In summary, Shiga and Shiga-like toxins may bind platelets via specific glycosphingolipid receptors. Such binding may contribute to the thrombocytopenia, platelet activation, and microthrombus formation observed in hemolytic-uremic syndrome.

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