A blood-based biomarker panel indicates IL-10 and IL-12/23p40 are jointly associated as predictors of β-amyloid load in an AD cohort

Alzheimer\u27s Disease (AD) is the most common form of dementia, characterised by extracellular amyloid deposition as plaques and intracellular neurofibrillary tangles of tau protein. As no current clinical test can diagnose individuals at risk of developing AD, the aim of this project is to evaluate a blood-based biomarker panel to identify individuals who carry this risk. We analysed the levels of 22 biomarkers in clinically classified healthy controls (HC), mild cognitive impairment (MCI) and Alzheimer\u27s participants from the well characterised Australian Imaging, Biomarker and Lifestyle (AIBL) study of aging. High levels of IL-10 and IL-12/23p40 were significantly associated with amyloid deposition in HC, suggesting that these two biomarkers might be used to detect at risk individuals. Additionally, other biomarkers (Eotaxin-3, Leptin, PYY) exhibited altered levels in AD participants possessing the APOE ϵ4 allele. This suggests that the physiology of some potential biomarkers may be altered in AD due to the APOE ϵ4 allele, a major risk factor for AD. Taken together, these data highlight several potential biomarkers that can be used in a blood-based panel to allow earlier identification of individuals at risk of developing AD and/or early stage AD for which current therapies may be more beneficial

Structural studies on the O-linked carbohydrate chains of human platelet glycocalicin

Glycocalicin (140 kDa), constituting the main part of glycoprotein Ib (160 kDa), was released from the human platelet membrane by the action of a Ca2+-dependent protease, present in the platelet cytoplasm and liberated during sonication of the platelet suspension. After activation of the protease by Ca2+, the sonicated plateled suspension was subjected to differential centrifugation. The supernatant was applied to a column of wheat germ agglutinin linked to Sepharose 4B; glycocalicin was eluted from the column with 2.5% (w/v) N-acetylglucosamine. Glycocalicin was found to contain 40% carbohydrate by weight, representing N- as well as O-glycosidically linked carbohydrate chains. The O-glycosidic chains were split off by alkaline cleavage in the presence of 3H-labelled NaBH4. The liberated 3H-labelled oligosaccharide-alditols were fractionated on a DEAE-Sephadex A-25 column. The structures of the oligosaccharide-alditols were investigated by 500-MHz 1H-NMR spectroscopy. The major compound was identified as NeuAc alpha(2->3)Galbeta(1->3)[NeuAcalpha(2->3)Galbeta(1->4)GlcNAcbeta(1->6)]GalNAc-ol. Two minor compounds were found to be NeuAcalpha(2->3)Galbeta(1->3)[NeuAcalpha(2->6)]GalNAc-ol and NeuAcalpha(2->3)Galbeta(1->3)GalNAc-ol

Identification of a tetrasialylated monofucosylated tetraantennary N-linked carbohydrate chain in human platelet glycocalicin

Glycocalicin (140 kDa), the main constituent of the glycoprotein Ib alpha-chain (150 kDa) of the human platelet membrane, contains 4 putative N-glycosylation sites. For the structural analysis of the N-glycosidic carbohydrate chains of glycocalicin, the glycoprotein has been subjected to the hydrazinolysis procedure. The acidic carbohydrate chains obtained were fractionated by ion-exchange chromatography on DEAE-Sephadex A-25, subsequently analysed by sugar analysis, anion-exchange chromatography on Mono Q HR 5/5 500 MHz 1H-NMR spectroscopy. A novel tetrasialylated monofucosylated tetraantennary chain was identified in the glycoprotein. It could also be deduced that in all structures the alpha2¨6-linked NeuAc is attached exclusively at the Gal beta 1¨4GlcNAc beta 1¨2Man alpha 1¨3 antenna, whereas the other antennae can be terminated with alpha2¨3-linked NeuAc. As minor constituents sialylated N-linked carbohydrate chains with a terminal Fuc alpha1¨2Gal beta1¨. sequence were detected

Role of sialic acid for platelet life span: exposure of β-galactose results in the rapid clearance of platelets from the circulation by asialoglycoprotein receptor–expressing liver macrophages and hepatocytes

Although surface sialic acid is considered a key determinant for the survival of circulating blood cells and glycoproteins, its role in platelet circulation lifetime is not fully clarified. We show that thrombocytopenia in mice deficient in the St3gal4 sialyltransferase gene (St3Gal-IV−/− mice) is caused by the recognition of terminal galactose residues exposed on the platelet surface in the absence of sialylation. This results in accelerated platelet clearance by asialoglycoprotein receptor-expressing scavenger cells, a mechanism that was recently shown to induce thrombocytopenia during Streptococcus pneumoniae sepsis. We now identify platelet GPIbα as a major counterreceptor on ST3Gal-IV−/− platelets for asialoglycoprotein receptors. Moreover, we report data that establish the importance of sialylation of the von Willebrand factor in its function

Impact of Neoadjuvant Therapy in Resected Pancreatic Ductal Adenocarcinoma of the Pancreatic Body or\ua0Tail on Surgical and Oncological Outcome: A Propensity-Score\ua0Matched Multicenter Study

Background: Several studies have suggested a survival benefit of neoadjuvant therapy (NAT) for pancreatic ductal adenocarcinoma (PDAC) in the pancreatic head. Data concerning NAT for PDAC located in pancreatic body or tail are lacking. Methods: Post hoc analysis of an international multicenter retrospective cohort of distal pancreatectomy for PDAC in 34 centers from 11 countries (2007\u20132015). Patients who underwent resection after NAT were matched (1:1 ratio), using propensity scores based on baseline characteristics, to patients who underwent upfront resection. Median overall survival was compared using the stratified log-rank test. Results: Among 1236 patients, 136 (11.0%) received NAT, most frequently FOLFIRINOX (25.7%). In total, 94 patients receiving NAT were matched to 94 patients undergoing upfront resection. NAT was associated with less postoperative major morbidity (Clavien\u2013Dindo 65 3a, 10.6% vs. 23.4%, P = 0.020) and pancreatic fistula grade B/C (9.6% vs. 21.3%, P = 0.026). NAT did not improve overall survival [27 (95% CI 14\u201339) versus 31 months (95% CI 19\u201342), P = 0.277], as compared with upfront resection. In a sensitivity analysis of 251 patients with radiographic tumor involvement of splenic vessels, NAT (n = 37, 14.7%) was associated with prolonged overall survival [36 (95% CI 18\u201353) versus 20 months (95% CI 15\u201324), P = 0.049], as compared with upfront resection. Conclusion: In this international multicenter cohort study, NAT for resected PDAC in pancreatic body or tail was associated with less morbidity and pancreatic fistula but similar overall survival in comparison with upfront resection. Prospective studies should confirm a survival benefit of NAT in patients with PDAC and splenic vessel involvement