Blood platelet surface interactions on fibrinogen under flow as viewed with fluorescent video-microscopy

The interaction of fluorescently labeled blood platelets with fibrinogen-coated glass was studied in Poiseuille flow at 3 wall shear rates, 40, 80 and 944 s-1. Observations were made via video-microscopy at a distance of 0.5 cm from a tube's entrance over a 1370 microns 2 portion of luminal area. The rates of arrival and detachment, and the net rate of adhesion of cells increased nonlinearly with flow rate. The fraction of arriving cells, first contacts, which adhered without subsequent movement and the fraction of arriving cells which adhered, moved to new positions and then remained adherent, were maximal at 80 s-1. For platelets which adhere and then move to a number of new positions, the likelihood of permanent adhesion is greater than 85 percent. The adhesion process is one in which 40-60 percent of cells permanently adhere on first contact with an additional 30 percent adhering after several moves along the surface. Cells contacting where a platelet was previously adherent had a greater chance of adhering than they would on an unaltered fibrinogen surface. The efficiency of platelet adhesion is greater for second contacts than for first contacts on unaltered fibrinogen coated surface.     

Platelet adhesion to polyurethane blended with polytetramethylene oxide

The surface and blood compatibility characteristics of Pellethane polyurethane blended with 1% or 5% (w/w) polytetramethylene oxide (PTMO) were evaluated. Analysis by X-ray photoelectron spectroscopy indicated that blending of PTMO caused an increased amount of amide wax, a processing agent present in Pellethane, to be expressed on the surface of the blended films in vacuo. Dynamic contact angle measurements in water, however, showed that PTMO was preferentially expressed on the blend film surfaces in water. The two lower molecular weight species, PTMO and amide wax, were thus capable of reorienting, depending on the environmental conditions. An in vitro assay of platelet adherence and thrombosis showed that polyurethane blended with 5% PTMO had about two-thirds fewer adherent platelets compared to unblended polyurethane and that a blend containing 1% PTMO was intermediate in platelet adherence. Measurements of albumin adsorption from binary solution with fibrinogen indicated that PTMO blends did not preferentially adsorb albumin compared to unblended polyurethane. (c) 1996 John Wiley & Sons, Inc.     

Formation of reactive oxygen species in monocytes at adhesion to glass

Processes of oxygen activation in monocytes stimulated with adhesion to glass were studied by methods of luminol-dependent and lucigen-independent chemiluminescence. It was shown that monocyte chemiluminescence was caused by cell adhesion to glass surface. Generation of reactive oxygen species at monocyte adhesion to glass was dependent on calcium ion concentration in the medium. The increase in the level of cytosolic calcium, as the extracellular calcium concentration elevated, was accompanied by the activation of phospholipase A2, 5-lypoxygenase and cycloxygenases. Magnesium ions exerted no influence on oxygen activation by cells. Incubation of cells in glucose-free medium, or the addition of glycolysis blocker (2-deoxy-D-glucose) to cell suspension led to a decrease in chemiluminescence intensity. By means of inhibitory analysis, it has been established that processes of oxygen activation are related to arachidonic acid metabolism, and depend on the activity of phospholipase A2.     

Platelet adhesion onto the wall of a flow chamber with an obstacle

In the present study, the data of the initial adhesion of platelets onto the wall of a flow chamber with an obstacle in steady human blood flows were obtained. The flowfields and the distribution of stress-related factors were simulated numerically by a finite volume method and the fluid dynamic effect on the platelet adhesion is discussed. In addition to the wall shear effect, the normal stress effect was also taken into account. A parameter Vn/¦Vt¦ was devised to assess the combined effect of both shear and normal forces in platelet adhesion. It was found that the peak adhesion occurred next to, but not on, the impingement point on the obstacle where the value of Vn/¦Vt¦ was negative. In these regions, direct impact played a major role in platelet adhesion. On the other hand, near the separation point before the obstacle where Vn/¦Vt¦ was insignificant, the mechanism was believed to be different from that in the direct impact region. Denser adhesion there might be caused by the accumulation and frequent collision of particles due to flow retardation and/or detour of the flow path. Interestingly, relatively low adhesion was found inside the recirculation regions. These results show that the normal stress effect (impingement) should be considered in platelet adhesion in addition to the shear effect.     

Platelet adhesion to collagen-coated wells: analysis of this complex process and a comparison with the adhesion to matrigel-coated wells.

The mechanisms of platelet adhesion to collagen type III-coated wells and Matrigel-coated wells were analyzed. The adhesion of 51Cr-labeled platelets to collagen-coated wells showed a biphasic pattern. The early stage of adhesion was inhibited by antibodies against platelet glycoprotein(GP)s Ia/IIa and VI. The later stage of platelet adhesion was inhibited by an antibody against the GPIIb/IIIa complex and a concomitant release of 14C-labeled serotonin was observed. The percentage of adhered platelets was increased when a higher platelet concentration was added in the reaction medium. These results indicated that the adhesion assay of platelets to collagen-coated wells was composed of two reactions: the first one is the platelet-collagen interaction that depends on GPIa/IIa and GPVI on the platelet surface; and the second reaction is the platelet-platelet interaction, platelet aggregation, which depends on GPIIb/IIIa. The adhesion of platelets to Matrigel-coated wells was indicated to involve platelet-Matrigel interactions that were partly dependent on the laminin in the Matrigel solution.     

Hexapod Walking: an expansion to Walknet dealing with leg amputations and force oscillations

The control of the legs of a walking hexapod is a complex problem as the legs have three joints each, resulting in a total of 18 degrees of freedom. We addressed this problem using a decentralized architecture termed Walknet, which consists of peripheral pattern generators being coordinated through influences acting mainly between neighbouring legs. Both, the coordinating influences and the local control modules (each acting only on one leg), are biologically inspired. This investigation shows that it is possible to adapt this approach to account for additional biological data by (1) changing the structure of the selector net in a biological plausible way (including force as an analog variable), (2) introducing a biologically motivated coordination influence for coactivation between legs and (3) adding a hypothetical influence between hind and front legs. This network of controllers has been tested using a dynamic simulation. It is able to describe (a) the behaviour of animals walking with one or two legs being amputated and (b) force oscillations that occur in a specific experimental situation, the standing legs of a walking animal.     

Cell adhesion to agrin presented as a nanopatterned substrate is consistent with an interaction with the extracellular matrix and not transmembrane adhesion molecules

Background  

Molecular spacing is important for cell adhesion in a number of ways, ranging from the ordered arrangement of matrix polymers extracellularly, to steric hindrance of adhesion/signaling complexes intracellularly. This has been demonstrated using nanopatterned RGD peptides, a canonical extracellular matrix ligand for integrin interactions. Cell adhesion was greatly reduced when the RGD-coated nanoparticles were separated by more than 60 nm, indicating a sharp spacing-dependent threshold for this form of cell adhesion.     

Platelet expression of CD40/CD40 ligand and its relation to inflammatory markers and adhesion molecules in patients with atrial fibrillation

Recent studies suggest the importance of prothrombotic and proinflammatory cascades in vascular thrombus formation. However, the impact of platelet CD40 and CD40 ligand (CD40L) expression and its relation to inflammatory markers in atrial clot formation have not yet been determined. Therefore, we studied a total of 40 patients. A total of 20 patients with persistent atrial fibrillation (AF) and 20 matched patients with sinus rhythm (SR) were included to quantify platelet surface expression of CD40/CD40L, serum levels of intercellular adhesion molecule-1 (ICAM), vascular adhesion molecule-1 (VCAM), high-sensitivity C-reactive protein (hsCRP), and monocyte chemoattractant protein-1 (MCP-1). Using fluorescence-activated cell sorting analysis, baseline CD40 expression (antibody binding capacity [ABC]) was increased during AF (AF: 7776 +/- 8.46 ABC vs. SR: 7753 +/- 7.32 ABC; P < 0.05), whereas CD40L expression was not different. In contrast to the effect of adenosine diphosphate, ex vivo stimulation with thrombin receptor activating peptide (TRAP) increased CD40 and CD40L expression in both groups. MCP-1, hsCRP, ICAM, and VCAM levels were significantly increased during AF, reaching highest levels in patients with atrial thrombi. Importantly, VCAM and MCP-1 were independent predictors for atrial thrombi (P < 0.05) using multivariate analysis. In contrast to declining levels of hsCRP, levels of ICAM, VCAM, MCP-1, and platelet CD40 expression remained elevated 5 weeks after successful electrical direct current cardioversion (CV). In conclusion, prothrombogenic markers are substantially elevated in patients with AF, reaching highest levels in patients with AF and atrial thrombi. Interestingly, amounts of adhesion molecules and platelet CD40 levels remain elevated even 5 weeks after successful CV, which may imply a persistently increased risk for atrial thrombus formation. In addition to hsCRP, MCP-1 and VCAM may serve as new biomarkers, which may help to identify patients with an increased risk for thromboembolic events.     

Bi-FoRe:an efficient bidirectional knockin strategy to generate pairwise conditional alleles with fluorescent indicators

Gene expression labeling and conditional manipulation of gene function are important for elaborate dissection of gene function.However,contemporary generation of pairwise dual-function knockin alleles to achieve both conditional and geno-tagging effects with a single donor has not been reported.Here we first developed a strategy based on a flipping donor named FoRe to generate conditional knockout alleles coupled with fluorescent allele-labeling through NHEJ-mediated unidirectional targeted insertion in zebrafish facilitated by the CRISPR/Cas system.We demonstrated the feasibility of this strategy at sox10 and isl1 loci,and successfully achieved Cre-induced conditional knockout of target gene function and simultaneous switch of the fluorescent reporter,allowing generation of genetic mosaics for lineage tracing.We then improved the donor design enabling efficient one-step bidirectional knockin to generate paired positive and negative conditional alleles,both tagged with two different fluorescent reporters.By introducing Cre recombinase,these alleles could be used to achieve both conditional knockout and conditional gene restoration in parallel;furthermore,differential fluorescent labeling of the positive and negative alleles enables simple,early and efficient realtime discrimination of individual live embryos bearing different genotypes prior to the emergence of morphologically visible phenotypes.We named our improved donor as Bi-FoRe and demonstrated its feasibility at the sox10 locus.Furthermore,we eliminated the undesirable bacterial backbone in the donor using minicircle DNA technology.Our system could easily be expanded for other applications or to other organisms,and coupling fluorescent labeling of gene expression and conditional manipulation of gene function will provide unique opportunities to fully reveal the power of emerging single-cell sequencing technologies.     

Inhibition of Streptococcus mutans NS adhesion to glass with and without a salivary conditioning film by biosurfactant- releasing Streptococcus mitis strains

The release of biosurfactants by adhering microorganisms as a defense mechanism against other colonizing strains on the same substratum surface has been described previously for probiotic bacteria in the urogenital tract, the intestines, and the oropharynx but not for microorganisms in the oral cavity. Two Streptococcus mitis strains (BA and BMS) released maximal amounts of biosurfactants when they were grown in the presence of sucrose and were harvested in the early stationary phase. The S. mitis biosurfactants reduced the surface tensions of aqueous solutions to about 30 to 40 mJ m(-2). Biochemical and physicochemical analyses revealed that the biosurfactants released were glycolipids. An acid-precipitated fraction was extremely surfactive and was identified as a rhamnolipidlike compound. In a parallel-plate flow chamber, the number of Streptococcus mutans NS cells adhering to glass with and without a salivary conditioning film in the presence of biosurfactant-releasing S. mitis BA and BMS (surface coverage, 1 to 4%) was significantly reduced compared with the number of S. mutans NS cells adhering to glass in the absence of S. mitis. S. mutans NS adhesion in the presence of non-biosurfactant-releasing S. mitis BA and BMS was not reduced at all. In addition, preadsorption of isolated S. mitis biosurfactants to glass drastically reduced the adhesion of S. mutans NS cells and the strength of their bonds to glass, as shown by the increased percentage of S. mutans NS cells detached by the passage of air bubbles through the flow chamber. Preadsorption of the acid-precipitated fraction inhibited S. mutans adhesion up to 80% in a dose-responsive manner. These observations indicate that S. mitis plays a protective role in the oral cavity and protects against colonization of saliva-coated surfaces by cariogenic S. mutans.     

Leukocyte adhesion molecule-1 (LAM-1, L-selectin) interacts with an inducible endothelial cell ligand to support leukocyte adhesion.

The human lymphocyte homing receptor, LAM-1, mediates the adhesion of lymphocytes to specialized high endothelial venules (HEV) of peripheral lymph nodes. We now report that LAM-1 is also a major mediator of leukocyte attachment to activated human endothelium. In a novel adhesion assay, LAM-1 was shown to mediate approximately 50% of the adhesion of both lymphocytes and neutrophils to TNF-activated human umbilical vein endothelial cells at 4 degrees C. The contribution of LAM-1 to leukocyte adhesion was only detectable when the assays were carried out under rotating (nonstatic) conditions, suggesting that LAM-1 is involved in the initial attachment of leukocytes to endothelium. In this assay at 37 degrees C, essentially all lymphocyte attachment to endothelium was mediated by LAM-1, VLA-4/VCAM-1, and the CD11/CD18 complex, whereas neutrophil attachment was mediated by LAM-1, endothelial-leukocyte adhesion molecule-1, and CD11/CD18. Thus, multiple receptors are necessary to promote optimal leukocyte adhesion to endothelium. LAM-1 also appeared to be involved in optimal neutrophil transendothelial migration using a videomicroscopic in vitro transmigration model system. LAM-1-dependent leukocyte adhesion required the induction and surface expression of a neuraminidase-sensitive molecule that was expressed for at least 24 h on activated endothelium. Expression of the LAM-1 ligand by endothelium was optimally induced by LPS and the proinflammatory cytokines TNF-alpha and IL-1 beta, whereas IFN-gamma and IL-4 induced lower levels of expression. The LAM-1 ligand on HEV and cytokine treated endothelium may be similar carbohydrate-containing molecules, because phosphomannan monoester core complex from yeast Hansenula hostii cell wall blocked binding of lymphocytes to both cell types, and identical epitopes on LAM-1-mediated lymphocyte attachment to HEV and activated endothelium. Thus, LAM-1 and its inducible endothelial ligand constitute a new pair of adhesion molecules that may regulate initial leukocyte/endothelial interactions at sites of inflammation.     

8-vinyl-deoxyadenosine, an alternative fluorescent nucleoside analog to 2'-deoxyribosyl-2-aminopurine with improved properties

We report here the synthesis and the spectroscopic characterization of 8-vinyl-deoxyadenosine (8vdA), a new fluorescent analog of deoxyadenosine. 8vdA was found to absorb and emit in the same wavelength range as 2′-deoxyribosyl-2-aminopurine (2AP), the most frequently used fluorescent nucleoside analog. Though the quantum yield of 8vdA is similar to that of 2AP, its molar absorption coefficient is about twice, enabling a more sensitive detection. Moreover, the fluorescence of 8vdA was found to be sensitive to temperature and solvent but not to pH (around neutrality) or coupling to phosphate groups. Though 8vdA is base sensitive and susceptible to depurination, the corresponding phosphoramidite was successfully prepared and incorporated in oligonucleotides of the type d(CGT TTT XNX TTT TGC) where N = 8vdA and X = A, T or C. The 8vdA-labeled oligonucleotides gave more stable duplexes than the corresponding 2AP-labeled sequences when X = A or T, indicating that 8vdA is less perturbing than 2AP and probably adopts an anti conformation to preserve the Watson–Crick H-bonding. In addition, the quantum yield of 8vdA is significantly higher than 2AP in all tested oligonucleotides in both their single strand and duplex states. The steady-state and time-resolved fluorescence parameters of 8vdA and 2AP were found to depend similarly on the nature of their flanking residues and on base pairing, suggesting that their photophysics are governed by similar mechanisms. Taken together, our data suggest that 8vdA is a non perturbing nucleoside analog that may be used with improved sensitivity for the same applications as 2AP.     

Effect of medium pH on oxygen activation by human blood neutrophils and lymphocytes during adhesion to glass and treatment with concanavalin A

It has been established that oxygen activation by neutrophils and human blood lymphocytes at adhesion to glass and under the action of concanavalin A differently depends on pH. It has been suggested that oxygen activation by neutrophils and lymphocytes occurs through different mechanisms.     

Tree range expansion in eastern North America fails to keep pace with climate warming at northern range limits

Rising global temperatures are suggested to be drivers of shifts in tree species ranges. The resulting changes in community composition may negatively impact forest ecosystem function. However, long‐term shifts in tree species ranges remain poorly documented. We test for shifts in the northern range limits of 16 temperate tree species in Quebec, Canada, using forest inventory data spanning three decades, 15° of longitude and 7° of latitude. Range shifts were correlated with climate warming and dispersal traits to understand potential mechanisms underlying changes. Shifts were calculated as the change in the 95th percentile of latitudinal occurrence between two inventory periods (1970–1978, 2000–2012) and for two life stages: saplings and adults. We also examined sapling and adult range offsets within each inventory, and changes in the offset through time. Tree species ranges shifted predominantly northward, although species responses varied. As expected shifts were greater for tree saplings, 0.34 km yr^?1, than for adults, 0.13 km yr^?1. Range limits were generally further north for adults compared to saplings, but the difference diminished through time, consistent with patterns observed for range shifts within each life stage. This suggests caution should be exercised when interpreting geographic range offsets between life stages as evidence of range shifts in the absence of temporal data. Species latitudinal velocities were on average <50% of the velocity required to equal the spatial velocity of climate change and were mostly unrelated to dispersal traits. Finally, our results add to the body of evidence suggesting tree species are mostly limited in their capacity to track climate warming, supporting concerns that warming will negatively impact the functioning of forest ecosystems.     

Fluorolabeling of antibody variable domains with green fluorescent protein variants: application to an energy transfer-based homogeneous immunoassay

A site-specific and efficient fluorolabeling of antibody variable regions with green fluorescent protein (GFP) variants and its application to an energy transfer-based homogeneous fluoroimmunoassay (open sandwich FIA) were attempted. Two chimeric proteins, Trx-V(H)-EBFP and Trx-V(L)-EGFP, consisting of V(H) and V(L) fragments of anti-hen egg lysozyme (HEL) antibody HyHEL-10 and two GFP color variants, EBFP and EGFP, respectively, were designed to be expressed in cytoplasm of trxB - mutant Escherichia coli as fusions with thioredoxin from E.coli The mixture of two proteins could be purified with HEL-affinity chromatography, retaining sufficient intrinsic fluorescence and binding activity to HEL. A significant increase in fluorescence resonance energy transfer (FRET) dependent on HEL concentration was observed, indicating the reassociation of the V(H) and V(L) domains of these chimeric proteins due to co-existing antigen. With this open sandwich FIA, an HEL concentration of 1-100 microg/ml could be non-competitively determined. The assay could be performed in a microplate format and took only a few minutes to obtain a sufficient signal after simple mixing of the chimeric proteins with samples. This represents the first demonstration that the FRET between GFP variants is applicable to homogeneous immunoassay.     

3H]AVP binding to rat renal tubular receptors during long-term treatment with an antagonist of arginine vasopressin

The interaction of an antagonist of arginine vasopressin (AVP), d(CH2)5-D-Tyr(Et)VAVP, with renal tubular V2 receptors were studied in medullary membrane preparations from kidneys of Sprague-Dawley and Brattleboro rats. In both rat strains, V2 receptors had comparable KD and Bmax values for binding of [3H]AVP. In vitro studies revealed that the V2-antagonist was more potent than cold AVP in displacing [3H]AVP. In vivo treatment of Sprague-Dawley rats with the antagonist over one week resulted only in a transient state of diabetes insipidus (DI). No specific [3H]AVP binding was detectable throughout the period of administration. Chronic treatment of Brattleboro rats resulted in a complete normalization of water intake. This agonistic effect was also associated with undetectable [3H]AVP binding. After stopping the infusion of d(CH2)5-D-Tyr(Et)VAVP, Bmax values tended to rise but had still not reached base line values after 6 days. In contrast, the chronic infusion of AVP in Brattleboro rats resulted in a reduction in water intake which was accompanied by a decreased Bmax. [3H]AVP binding remained detectable during the entire treatment period. Thereafter Bmax was restored to base line values within 2 days of stopping the infusion. These results suggest that d(CH2)5-D-Tyr(Et)VAVP has a high affinity for V2 receptors in both Sprague-Dawley and Brattleboro rats. Its rate of dissociation from the receptor appears to be much slower than that of AVP. In Brattleboro rats, the binding of d(CH2)5-D-Tyr(Et)VAVP leads to an antidiuretic response. In Sprague-Dawley rats, a transient diuretic response is followed by a progressive normalization in water intake. This occurs despite persistent and complete blockade of renal medullary V2 receptors.     

The association of ASAP1, an ADP ribosylation factor-GTPase activating protein,with focal adhesion kinase contributes to the process of focal adhesion assembly

ASAP1 (ADP ribosylation factor [ARF]- GTPase-activating protein [GAP] containing SH3, ANK repeats, and PH domain) is a phospholipid-dependent ARF-GAP that binds to and is phosphorylated by pp60(Src). Using affinity chromatography and yeast two-hybrid interaction screens, we identified ASAP1 as a major binding partner of protein tyrosine kinase focal adhesion kinase (FAK). Glutathione S-transferase pull-down and coimmunoprecipitation assays showed the binding of ASAP1 to FAK is mediated by an interaction between the C-terminal SH3 domain of ASAP1 with the second proline-rich motif in the C-terminal region of FAK. Transient overexpression of wild-type ASAP1 significantly retarded the spreading of REF52 cells plated on fibronectin. In contrast, overexpression of a truncated variant of ASAP1 that failed to bind FAK or a catalytically inactive variant of ASAP1 lacking GAP activity resulted in a less pronounced inhibition of cell spreading. Transient overexpression of wild-type ASAP1 prevented the efficient organization of paxillin and FAK in focal adhesions during cell spreading, while failing to significantly alter vinculin localization and organization. We conclude from these studies that modulation of ARF activity by ASAP1 is important for the regulation of focal adhesion assembly and/or organization by influencing the mechanisms responsible for the recruitment and organization of selected focal adhesion proteins such as paxillin and FAK.     

Proximal tubular injury and rapid formation of atubular glomeruli in mice with unilateral ureteral obstruction: a new look at an old model

Unilateral ureteral obstruction (UUO), employed extensively as a model of progressive renal interstitial fibrosis, results in rapid parenchymal deterioration. Atubular glomeruli are formed in many renal disorders, but their identification has been limited by labor-intensive available techniques. The formation of atubular glomeruli was therefore investigated in adult male mice subjected to complete UUO under general anesthesia. In this species, the urinary pole of Bowman's capsule is normally lined by tall parietal epithelial cells similar to those of the proximal tubule, and both avidly bind Lotus tetragonolobus lectin. Following UUO, these cells became flattened, lost their affinity for Lotus lectin, and no longer generated superoxide (revealed by nitroblue tetrazolium infusion). Based on Lotus lectin staining, stereological measurements, and serial section analysis, over 80% of glomeruli underwent marked transformation after 14 days of UUO. The glomerulotubular junction became stenotic and atrophic due to cell death by apoptosis and autophagy, with concomitant remodeling of Bowman's capsule to form atubular glomeruli. In this degenerative process, transformed epithelial cells sealing the urinary pole expressed α-smooth muscle actin, vimentin, and nestin. Although atubular glomeruli remained perfused, renin immunostaining was markedly increased along afferent arterioles, and associated maculae densae disappeared. Numerous progressive kidney disorders, including diabetic nephropathy, are characterized by the formation of atubular glomeruli. The rapidity with which glomerulotubular junctions degenerate, coupled with Lotus lectin as a marker of glomerular integrity, points to new investigative uses for the model of murine UUO focusing on mechanisms of epithelial cell injury and remodeling in addition to fibrogenesis.     

Glycoconjugates with NeuAc-NeuAc-Gal-Glc are more effective at preventing adhesion of Helicobacter pylori to gastric epithelial cells than glycoconjugates with NeuAc-Gal-Glc.

Helicobacter pylori (H. pylori) adheres to human gastric epithelial cells, eliciting various gastroduodenal diseases. Gangliosides play a critical role in bacterial adhesion to cell surfaces. The present study examined how residues of gangliosides are important for inhibition of adhesion of H. pylori to MKN-45 cells. We measured adhesion or detachment effects of gangliosides on the interaction between MKN-45 cells and H. pylori, as well as interleukin-8 production. Among the gangliosides, O-Ac-GD3, GT(1b), GD(1a), GD(1b), GT(1a), and GD3 had potent dose dependent inhibitory effects on adhesion of H. pylori to MKN-45 cells, interleukin-8 production, and vacuole formation induced by H. pylori toxin binding to Vero cells. GD3 also accelerated bacterial detachment of MKN-45 cells with adherent H. pylori in a dose dependent manner. Such results strongly suggest that the mechanism involved in the inhibition of H. pylori adhesion is mediated by the variations of the residues of the NeuAc-NeuAc-Gal-Glc chain of gangliosides. NeuAc-NeuAc-Gal-Glc exhibits a more inhibitory effect on adhesion than the NeuAc-Gal-Glc chain. Such gangioside and oligosaccrharide sequences appear to have therapeutic importance for prevention of H. pylori adhesion, as well as reduction of both inflammation and gastric mucosal injuries.