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A Lundblad

Publications and source records attributed to A Lundblad.

At least 55 records · Page 3Linked to original sources
PubMed1988

Oligosaccharides from faeces of a blood-group B, breast-fed infant.

Eight oligosaccharides have been isolated from faeces of a blood group B, secretor, breast-fed infant and characterized by sugar and methylation analysis, f.a.b. mass spectrometry and 1H-n.m.r. spectroscopy. One of these oligosaccharides has not previously been reported and is a tri-L-fucosyl derivative of lacto-N-hexaose. The other compounds were identical to oligosaccharides found in human milk. Several of the reported compounds require the secretor dependent 2'-fucosyltransferase for their biosynthesis. Since the mother of this child was an O(H) non-secretor, an intestinal biosynthesis of at least some of these compounds is strongly indicated. No blood group B active oligosaccharides were detected which is in sharp contrast to the oligosaccharide excretion in faeces from a blood group A infant [Sabharwal et al., Mol. Immunol., 21 (1984) 1105-1112] in which all the major oligosaccharides isolated were blood group A active.

ABO Blood-Group System↗
PubMed1988

A carbohydrate epitope associated with human squamous lung cancer.

A monoclonal antibody, 43-9F, specifically recognizes a tumor-associated antigen expressed both on surface membrane glycoproteins and on secreted soluble mucins of human squamous lung carcinoma (SLC) cells, and the corresponding antigen can be detected as a circulating tumor marker in plasma of SLC patients. Thin-layer chromatography immunostaining of neutral glycolipids extracted from SLC cells reveals a 43-9F-reactive glycolipid whose carbohydrate structure, as determined by fast atom bombardment-mass spectrometry, is identical with that of an Lea-active pentaglycosylceramide described previously: Gal beta 1-3[Fuc alpha 1-4]-GlcNAc beta 1-3Gal beta 1-4Glc-Cer. However, the Lea-active oligosaccharide hapten, lacto-N-fucopentaose II, with the same carbohydrate structure, fails to inhibit binding of 43-9F, and a well-characterized anti-Lea monoclonal antibody blocks only 40% of 43-9F binding sites on SLC cells, suggesting that the major epitope recognized by 43-9F is more complex than the Lea epitope. To search for a higher affinity 43-9F epitope among more complex oligosaccharides, a mixture of tritiated neutral oligosaccharide alditols from pooled human milk was passed through a 43-9F affinity column. A major retarded oligosaccharide was purified by high-performance liquid chromatography and shown by fast atom bombardment-mass spectrometry to have the following structure: Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4[Fuc alpha 1-3] GlcNAc beta 1-3Gal beta 1-4Glc. Oligosaccharides containing this sugar sequence are at least 100-fold more active than lacto-N-fucopentaose II as competitive inhibitors of 43-9F. Thus, antibody 43-9F binds to the above difucosyl Lea-X determinant with high affinity and weakly cross-reacts with the Lea antigen under some conditions such as occurs in thin-layer chromatography and enzyme-linked immunosorbent assay where multiple weak interactions of the decavalent IgM antibody may occur.

Antibodies, Monoclonal↗
PubMed1988

Monoclonal antibodies specific for oligosaccharides prepared by partial nitrous acid deamination of heparin.

Monoclonal antibodies were raised against a conjugate between heparin oligosaccharides and human serum albumin. The oligosaccharides were prepared by partial nitrous acid degradation of heparin and were coupled to human serum albumin by reductive amination. Characterization of the antibodies secreted by one of the resulting clones showed that they recognize a determinant present in the oligosaccharide antigen, but not in intact heparin, nor in a variety of related polysaccharides. Degradation of heparin by nitrous acid generates a 2,5-anhydro-D-mannose residue at the reducing end of the resulting oligosaccharides, and it is concluded that this structure is essential for interaction with the antibodies. Reduced oligosaccharides (containing a terminal anhydromannitol residue) are also active. After gel chromatography of partially degraded heparin, the smallest components capable of binding to the antibodies were found in a tetrasaccharide fraction. Affinity chromatography on immobilized monoclonal antibodies separated this tetrasaccharide fraction into distinct populations of binding and nonbinding species. Structural analysis showed that the tetrasaccharide fraction that bound to the monoclonal antibodies contained one single component with the structure IdoA(2-OSO3)-GlcNSO3 (6-OSO3)-IdoA(2-OSO3)-aManR(6-OSO3), whereas the fraction that did not bind to the antibodies contained a mixture of different structures.

Animals↗
PubMed1988

Novel approach to affinity chromatography using "weak" monoclonal antibodies.

Affinity purification generally relies on specific high-affinity recognition between two species of biological molecules: one molecular species (the ligate) dissolved in a mobile phase is selectively adsorbed to the other species (the ligand) coupled to a solid support. Desorption of the ligate often requires harsh conditions that degrade biological activity of the purified product. As an alternative to this general procedure, we have studied affinity chromatography in a weak affinity mode, where ligand-ligate interactions are in dynamic equilibrium. Ligates recognized with low affinities (dissociation constant greater than 10(-4) M) elute from affinity columns under mild, isocratic conditions as retarded peaks, separated from noninteracting solutes that elute in the void volume. To illustrate the procedure, we report chromatography of an oligosaccharide on a 2-ml column containing 86 mg of a monoclonal antibody coupled to 10-micron microparticulate silica particles. Using a temperature-sensitive antibody, we observed that when the ligand-ligate dissociation constant is greater than 10(-3) M, performance of the system exceeds 300 theoretical plates/10 cm column length and approaches the efficiencies generally associated with high-performance liquid chromatography.

Antibodies, Monoclonal↗
PubMed1988

Oligosaccharides from feces of preterm infants fed on breast milk.

Nine neutral and five acidic oligosaccharides were isolated from feces of a preterm (30th postmenstrual week) blood group A nonsecretor infant fed on pooled breast milk. Structural analyses were carried out using sugar and methylation analyses, fast atom bombardment mass spectrometry, and 1H NMR. The acidic oligosaccharides are well-known components of human milk. The neutral oligosaccharides are characteristic of nonsecretor milk. Surprisingly, no secretor gene-dependent oligosaccharides were present in the feces. Another preterm (27th postmenstrual week) blood group A, secretor infant fed on pooled breast milk showed the same fecal oligosaccharide pattern as above during the first week after birth, despite being a secretor individual. Also notable was the absence of blood group A-active oligosaccharides in this sample. Another sample of feces collected 8 weeks later from the latter infant contained the expected blood group A-active oligosaccharides. Furthermore, free sialic acid was present at the cost of the sialyl oligosaccharides seen earlier. Thus, infants born prematurely do not show the same degree of development of oligosaccharide metabolism as their more mature counterparts.

Carbohydrate Conformation↗
PubMed1988

Detection and isolation of oligosaccharides with Lea and Leb blood group activities by affinity chromatography using monoclonal antibodies.

Affinity columns prepared by immobilizing monoclonal antibodies that specifically recognize the Lea or the Leb blood group antigens can be used for analytical or preparative isolation of oligosaccharides with the corresponding reactivities. The number of immobilized functional antibody combining sites on a column and the dissociation constants for standard oligosaccharides are determined by frontal analysis. By employing a simple approximation [K.-I. Kasai et al. (1986) J. Chromatogr. 376, 33-47] these parameters can be used to rationally design columns with properties appropriate for zonal affinity chromatography. The affinity for binding of the Lea-active oligosaccharide lacto-N-fucopentaose II (LNF II) by the anti-Lea antibody CO-514 doubles for each 8 degrees C downward shift in temperature between 37 and 4 degrees C. By zonal chromatography, Lea- or Leb-active oligosaccharides are recovered from a complex mixture of milk oligosaccharides containing more than a 20-fold molar excess of structurally similar but antigenically distinct oligosaccharides. The capacity for preparative isolation of an oligosaccharide increases in a linear fashion with the amount of antibody loaded on the solid support. The monoclonal antibodies used in these studies are products of hybridomas derived from mice immunized with human colorectal carcinoma cell lines [M. Blaszczyk et al. (1984) Arch. Biochem. Biophys. 233, 161-168]. The experiments establish that affinity chromatography applied to mixtures of oligosaccharides released by enzymatic or chemical cleavage of glycoconjugates may simplify the task of isolating and characterizing biologically interesting target antigens of monoclonal antibodies.

Animals↗
PubMed1988

Intestinal-type glycosphingolipids in urine from patients with enterocutaneous urinary diversions.

Ureteroenterocutaneous stoma is a surgical procedure for urinary diversion by which an intestinal segment is used as a conduit or reservoir for the urine. The intestinal mucosa continues to produce a mucous gel containing desquamated epithelial cells. This mucous gel is easily obtainable from the urine. Glycosphingolipids were isolated from such gels and analyzed with immunological methods using a thin-layer chromatography overlay assay and mass spectrometry. The glycosphingolipids obtained mainly belong to the lacto-type I series comprising ABH, Lea, and Leb determinants. These observations support the intestinal origin of the glycosphingolipids. A regional distribution of the ABH and Lewis antigens, which is in accordance with previous immunohistochemical findings, was observed.

Chromatography, Thin Layer↗
PubMed1988

Distribution of some Gal beta 1-3(4)GlcNAc related carbohydrate antigens on the mouse uterine epithelium in relation to the peri-implantational period.

Using monoclonal antibodies of defined carbohydrate specificity we have looked at the distribution of various Gal beta 1-3(4)GlcNAc related oligosaccharide determinants in the mouse uterus during the first 6 days of pregnancy. Frozen sections of uterus from B6D2F1, B6CBF1 or B6D2F1/BOM female mice were incubated with the monoclonal antibodies and then with a fluorescein isothiocyanate conjugate of goat anti-mouse IgM and viewed by epifluorescence illumination. None of the antibodies bound specifically to stroma cells but antibodies recognising difucosylated Gal beta 1-3(4)GlcNAc structures, the monofucosylated type II determinant (SSEA-1) and an H type I oligosaccharide bound to cells of the uterine luminal epithelium and glands and to the uterine secretions. Antibodies recognising the three different types of saccharide showed independent changes in staining intensity during early pregnancy. The antibody which recognises H type I structures (667/9E9) showed a change in distribution from binding to most cells of the uterine epithelium in the non-pregnant mouse and on day 3 of pregnancy to binding restricted to areas of epithelial cells interspersed with non-staining clumps of cells between days 4 and 5 of pregnancy.

Animals↗
PubMed1988

The milk oligosaccharide, lacto-N-fucopentaose I, inhibits attachment of mouse blastocysts on endometrial monolayers.

Seven oligosaccharides isolated from human milk were tested for their effect in an in-vitro model of mouse blastocyst adhesion and trophoblast outgrowth on endometrial epithelial monolayers. One compound, lacto-N-fucopentaose I (LNF I), produced a significant reduction in the percentage of attached and outgrown blastocysts after co-culture for 72 h (P less than 0.001). No significant effect of any other tested oligosaccharide was obtained.

Animals↗
PubMed1988

Mucins obtained from patients with enterocutaneous urinary diversions.

The ureteroenterocutaneostomy is a surgical procedure for urinary diversion by which an intestinal segment is used as a conduit or a reservoir for urine. Histological studies on colonic segments have shown a well preserved mucosal surface with numerous goblet cells and urine from these patients contains a mucus-like sediment. The present study demonstrates that such gels are composed of mucins occurring predominantly as a glycoprotein complex which is 'insoluble' in 6 M guanidinium chloride. The complex was brought into solution by reduction of disulphide bonds and the fragments (subunits) obtained behaved as typical mucins when subjected to density-gradient centrifugation in CsCl/4 M guanidinium chloride. High-Mr glycopeptides obtained after trypsin digestion of subunits expressed the ABH and Lewis antigens, in accordance with the patients' blood-group phenotype and with the regional distribution known from previous immunohistochemical studies on normal colonic mucosa. A heterogeneous population of mucin glycopeptides was revealed by using high-performance ion-exchange chromatography and the major carbohydrate-containing peak did not coincide with that expressing the blood-group activity.

ABO Blood-Group System↗
PubMed1987

Nucleotide and translated amino acid sequences of cDNA coding for the variable regions of the light and heavy chains of mouse hybridoma antibodies to blood group A and B substances.

This is the first report of nucleotide and translated amino acid sequences of the variable region light (VL) and heavy (VH) chains of mouse monoclonal hybridoma anti-blood group A and B substances, the combining sites of which have been mapped. Monoclonal hybridoma anti-A and anti-B produced in BALB/c mice by immunization with A or B blood group substances, with A1 erythrocytes, and water-soluble blood group A substance or with synthetic B determinants coupled to bovine serum albumin or to O erythrocytes have been characterized immunochemically. To relate the immunochemical properties of the monoclonals to their primary structures, we have cloned and sequenced cDNAs of variable regions of light and heavy chains of two anti-A and two anti-B. The anti-A hybridomas have very similar combining site specificities and have almost identical VH sequences belonging to the J558 germ-line family, but their VL are from different germ-line VK gene families. The two anti-B hybridomas have different combining site specificities and use the same VL which differs completely from the anti-A VL; their VH are derived from different VH germ-line genes belonging to the J606 family. The results suggest that the heavy chains play a major role in determining the specificities of the antibody combining sites, with only minor contribution of VL. Additional sequence data on monoclonal antibodies of defined specificity for blood group substances are needed for further insights into the genetic and structural basis for their specificities.

ABO Blood-Group System↗
PubMed1987

Separation of blood group A-active oligosaccharides by high-pressure liquid affinity chromatography using a monoclonal antibody bound to concanavalin A silica.

A column for high-pressure liquid affinity chromatography is prepared by binding a murine monoclonal anti-blood group A antibody of IgM isotype to concanavalin A-coated silica particles. The column specifically retards blood group A-active oligosaccharides with the nonreducing immunodominant trisaccharide sequence, GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1- ..., and separates three A-active oligosaccharides with different core structures. Retention of the oligosaccharides on the column diminishes with increasing temperatures, permitting thermal elution in the range 25-50 degrees C.

ABO Blood-Group System↗
PubMed1987

A monoclonal anti-glycophorin A antibody recognizing the blood group M determinant: studies on the subspecificity.

A mouse monoclonal antibody (425/2B, IgM) was obtained which shows specificity for blood group M determinant of glycophorin A. The antibody is pH-dependent. At pH 6-7 it reacted strongly with blood group M antigen, but also cross-reacted distinctly with N antigen. At pH 8.3 the antibody showed moderately decreased reactivity with M antigen, but no interaction with N antigen was detectable by hemagglutination, immunoblotting, or microplate ELISA. The direct binding studies and inhibition of 425/B antibody by untreated or modified blood group M and N glycoproteins or tryptic glycopeptides showed that the binding to the antigens was not affected by acetylation of their amino groups, or removal of amino-terminal amino acid residue. Desialylation of the antigens decreased their reactivity with the antibody and this effect was distinctly stronger at pH 7 than 8.3. The antibody reacted strongly at pH 7 and 8.3 with glycophorin B of Henshaw phenotype, whereas its reactivity with normal glycophorin B was weak or undetectable at these pH values, respectively. The results obtained indicated that anti-M specificity of 425/2B antibody is related to the 5th amino acid residue of glycophorin A (anti-Mgly specificity) and that pH shift from 7 to 8.3 changes the fine specificity of the antibody. At pH 8.3 the reactivity of the antibody is more dependent on glycine residue (higher anti-M specificity) and less dependent on sialic acid residues in the antigen.

Animals↗
PubMed1987

Lewis blood group antigens in urine sediments from patients with urinary bladder carcinoma.

Urine sediments from 20 patients with urinary bladder carcinoma, and from 11 healthy individuals were investigated for their content of Lea and Leb active glycolipids. The investigation was restricted to blood group phenotype Le (a-b+). All individuals exhibited both Lea- and Leb-active glycolipids. In healthy individuals the ratio Lea/Leb was less than 1 in 10 out of 11 cases, whereas in patients with bladder cancer the ratio Lea/Leb was greater than 1 in 11 out of 20 cases. No correlation between the Lea/Leb ratio on the one hand and tumour grade or stage on the other hand could be shown. The results indicate one possible explanation for the loss of ABH antigens in bladder cancer and also demonstrate the potential of detailed biochemical investigations on exfoliated material in urine.

Carcinoma, Transitional Cell↗
PubMed1986

Separation and partial sequence analysis of blood group A-active oligosaccharides by affinity chromatography using monoclonal antibodies.

An affinity column containing an anti-blood group A monoclonal antibody coupled to Sepharose beads specifically retards oligosaccharides with the nonreducing trisaccharide sequence GalNAc alpha 1-3(Fuc alpha 1-2)Gal beta 1-R. Three A-active oligosaccharides, A-tetra, A-penta, and A-hepta, elute as retarded peaks, well-separated from unbound sugars. A-hepta, which contains a difucosylated type 1 (Leb) core structure, elutes much later than A-tetra or A-penta and can be completely separated from the latter oligosaccharides by affinity chromatography. The order of elution of the oligosaccharides agrees with their previously determined specific molar activities as inhibitors of quantitative immune precipitation [H.-T. Chen, and E. A. Kabat, (1985) J. Biol. Chem. 260, 13208-13217]. Treatment of A-hepta with Charonia lampas alpha-galactosaminidase abolishes its binding by the anti-A affinity column and converts it to a Leb-active oligosaccharide (lacto-N-difucohexaose I) that is specifically retarded on a second affinity column containing an anti-Leb monoclonal antibody.

ABO Blood-Group System↗
PubMed1986

Patterns of sarcomere activation, temperature dependence, and effect of ryanodine in chemically skinned cardiac fibers.

Functionally skinned and electrochemically shunted myocytes were prepared by perfusing rat hearts with collagenase in order to obtain a technically improved measurement of sarcomere dynamics and to evaluate the role of sarcoplasmic reticulum in situ with respect to contractile activation. In the presence of micromolar calcium, the myocytes exhibited phasic and propagated contraction waves beginning at one end and proceeding along the myocyte. Beating rates, the propagation velocity of the activation wave, and single sarcomere shortening and relaxation velocities were obtained by manual or automated analysis of 16-mm film recorded at 170 frames/s from a camera attached to a microscope that was equipped with a temperature-controlled stage. In parallel experiments, calcium accumulation by the sarcoplasmic reticulum of the myocytes in situ was measured by direct isotopic tracer methods. The frequency (10-38 min-1) of spontaneous contractions, the velocity (1.9-7.4 microns . s-1) of sarcomere shortening, and the velocity (1.7-6.8 microns . s-1) of sarcomere relaxation displayed identical temperature dependences (Q10 = 2.2), which are similar to that of the calcium pump of sarcoplasmic reticulum and are consistent with a rate limit imposed by enzyme-catalyzed mechanisms on all these parameters. On the other hand, the velocity (77-159 microns . s-1) of sequential sarcomere activation displayed a lower temperature dependence (Q10 = 1.5), which is consistent with a diffusion-limited and self-propagating release of calcium from one sarcomere to the other. The phasic contractile activity of the dissociated myocytes was inhibited by 10(-8)-10(6) M ryanodine (and not by myolemmal calcium blockers) under conditions in which calcium accumulation by sarcoplasmic reticulum in situ was demonstrated to proceed optimally. The effect of ryanodine is attributed to an interaction of this drug with sarcotubular structures, producing inhibition of calcium release from the sarcoplasmic reticulum. The consequent lack of sarcomere activation underlines the role of sarcoplasmic reticulum uptake and release in the phasic contractile activation of the electrochemically shunted myocytes.

Alkaloids↗