Constitutively hyposialylated human T-lymphocyte clones in the Tn-syndrome: binding characteristics of plant and animal lectins.

Previously, beta 1,3-galactosyltransferase-deficient (Tn+) and normal (TF+) T-lymphocyte clones have been established from a patient suffering from Tn-syndrome [Thurnher et al. (1992) Eur J Immunol 22: 1835-42]. Tn+ T lymphocytes express only Tn antigen GalNAc alpha 1-O-R) while other O-glycan structures such as sialosyl-Tn (Neu5Ac alpha 2,6GalNAc alpha 1-O-R) or TF (Gal beta 1-3GalNAc alpha 1-O-R) antigens are absent from these cells as shown by flow cytometry using specific mABs for TF and sialosyl-Tn antigen, respectively.

Localization of the putative sialic acid-binding site on the immunoglobulin superfamily cell-surface molecule CD22.

B-lymphocyte antigen CD22 is a member of the recently described sialoadhesin family of immunoglobulin-like cell-surface glycoproteins that bind glycoconjugates terminating in sialic acid. One prominent ligand for CD22 is the highly glycosylated leukocyte surface protein CD45. Using surface plasmon resonance spectroscopy, we characterized the interaction of recombinant mouse CD22 with native CD45 purified from rat thymus (CD45-thy).

Characterization of the sialic acid-binding site in sialoadhesin by site-directed mutagenesis.

The sialoadhesins are a distinct subgroup of the immunoglobulin superfamily, comprising sialoadhesin, CD22, the myelin-associated glycoprotein, and CD33. They can all mediate sialic acid-dependent binding to cells with distinct specificities. Sialoadhesin is a murine macrophage-restricted cell-surface molecule with 17 extracellular immunoglobulin-like domains that recognizes NeuAc alpha 2-3Gal in N- and O-glycans and interacts preferentially with cells of the granulocytic lineage.

HLA-B alleles of the Navajo: no evidence for rapid evolution in the Nadene.

New HLA-B locus alleles have been found in South American Amerindian populations but were largely absent in North American Amerindian tribes also descended from this first Paleo-Indian migration. We have now extended these studies to the Navajo, descendants of the second Nadene migration. No new functional alleles were found at the B locus of this tribe.

A role for sialoadhesin-positive tissue macrophages in host resistance to lymphoma metastasis in vivo.

Sialoadhesin (SER) is a newly described macrophage-restricted adhesion molecule with a sequence similarity to CD22 on B cells and to myelin-associated glycoprotein on Schwann cells. We describe here a functional role of SER+ spleen macrophages in antigen processing and presentation to T lymphocytes. In two syngeneic murine tumour systems (ESb-MP and lacZ transduced ESbL T-lymphoma cells), the activation state of SER+ macrophages (tested by activity of marker enzymes adenosine deaminase and 5'-nucleotidase) correlated with the arrest of lymphoma metastasis.

Molecular characterisation of ninein, a new coiled-coil protein of the centrosome.

We describe the cDNA cloning of ninein, a novel component of centrosomes. In the mouse, ninein is predicted to be an acidic protein (calculated pI of 4.8) with alternatively spliced forms of 245 kDa and 249 kDa that contain extensive regions of coiled-coil structure flanked by non-coiled ends.

The amino-terminal immunoglobulin-like domain of sialoadhesin contains the sialic acid binding site. Comparison with CD22.

Sialoadhesin and CD22 are members of a recently characterized family of sialic acid-dependent adhesion molecules belonging to the immunoglobulin superfamily. Sialoadhesin is a macrophage-restricted receptor containing 17 extracellular Ig-like domains which recognizes oligosaccharides terminating in NeuAc alpha 2-3Gal in N- and O-linked glycans. CD22 is a B cell-restricted receptor with seven Ig-like domains which selectively recognizes oligosaccharides terminating in NeuAc alpha 2-6Gal in N-glycans.

Intraosseous secondary calcium salt crystal deposition: an artefact of acid decalcification.

We previously observed, in decalcificated bone specimens, intraosseous crystal deposits with morphological and analytical similarity to calcium pyrophosphate dihydrate. We have now been able, by a combination of more detailed morphological studies of these and similar cases, and by infrared spectroscopy in three cases, to show that this is, in fact deposition of the secondary calcium salts brushite and monetite, occurring as an artefact during formic acid decalcification. Our earlier postulate of bone as an additional primary crystallization site for calcium pyrophosphate dihydrate is effectively disproved.

Sialoadhesin (Sn) maps to mouse chromosome 2 and human chromosome 20 and is not linked to the other members of the sialoadhesin family, CD22, MAG, and CD33.

Sialoadhesin is a cell-cell interaction molecule expressed by subpopulations of tissue macrophages. It contains 17 immunoglobulin (Ig)-like domains and is structurally related to CD22, MAG, and CD33. These molecules establish a distinct family of sialic acid-dependent adhesion molecules, the sialoadhesin family.

Characterization of CD33 as a new member of the sialoadhesin family of cellular interaction molecules.

CD33 is a member of the Ig superfamily that is restricted to cells of the myelomonocytic lineage but whose functions and binding properties are unknown. It shares sequence similarity with sialoadhesin, CD22, and the myelin-associated glycoprotein, which constitute the Sialoadhesin family of sialic acid-dependent cell adhesion molecules. In the present study, we show that CD33 is a fourth member of this family.

Extruded erythroblast nuclei are bound and phagocytosed by a novel macrophage receptor.

Resident bone marrow macrophages (RBMM) play an important role in clearance of nuclei extruded from late-stage erythroblasts (Eb). To investigate the nature of macrophage receptors involved in this process, extruded erythroblast nuclei (EEN) were purified by cultivation of erythroblasts with erythropoietin, followed by density gradient centrifugation. By electron microscopy, the majority of free nuclei had an intact plasma membrane.

Sialoadhesin binds preferentially to cells of the granulocytic lineage.

Sialoadhesin is a macrophage-restricted, sialic acid-dependent receptor of 185 kD that binds to the oligosaccharide sequence NeuAc alpha 2,3Gal on cell surface glycoconjugates. Recent cDNA cloning has shown that sialoadhesin is a new member of the immunoglobulin superfamily with sequence similarity to CD22, a sialic acid-dependent receptor of B lymphocytes. Sialoadhesin has been implicated in cellular interactions of stromal macrophages with developing myeloid cells.

Modifications of cell surface sialic acids modulate cell adhesion mediated by sialoadhesin and CD22.

An increasing number of mammalian cell adhesion molecules, including sialoadhesion, CD22 and the family of selectins, have been found to bind cell surface glycoconjugates containing sialic acids. Here we describe how the structural diversity of this sugar influences cell adhesion mediated by the related molecules sialoadhesin and CD22 in murine macrophages and B-cells respectively. We show that the 9-O-acetyl group of Neu5,9Ac2 and the N-glycoloyl residue of Neu5Gc interfere with sialoadhesin binding.

Sialoadhesin, a macrophage sialic acid binding receptor for haemopoietic cells with 17 immunoglobulin-like domains.

Sialoadhesin is a macrophage-restricted adhesion molecule of 185 kDa that mediates sialic acid-dependent binding to cells. It is expressed strongly by macrophages in lymphoid and haemopoietic tissues where it is likely to mediate cell-cell interactions. Here we report the molecular cloning of murine sialoadhesin and show that it is a new member of the immunoglobulin (Ig) superfamily with 17 Ig-like domains.

A novel role for myelin-associated glycoprotein as an inhibitor of axonal regeneration.

Following nerve injury, axons in the CNS do not normally regenerate. It has been shown that CNS myelin inhibits neurite outgrowth, though the nature of the molecules responsible for this effect are not known. Here, we demonstrate that the myelin-associated glycoprotein (MAG), a transmembrane protein of both CNS and PNS myelin, strongly inhibits neurite outgrowth from both developing cerebellar and adult dorsal root ganglion (DRG) neurons in vitro.

Isolation of the gene for McLeod syndrome that encodes a novel membrane transport protein.

McLeod syndrome is an X-linked multisystem disorder characterized by abnormalities in the neuromuscular and hematopoietic systems. We have assembled a cosmid contig of 360 kb that encompasses the McLeod gene locus. A 50 kb deletion was detected by screening DNA from patients with radiolabeled whole cosmids, and two transcription units were identified within this deletion.

Mouse sialoadhesin is not responsible for Candida albicans yeast cell binding to splenic marginal zone macrophages.

Candida albicans hydrophilic yeast cells specifically adhere to mouse macrophages in the splenic marginal zone and in lymph node subcapsular and medullary sinuses. These macrophages express sialoadhesin that binds erythrocytes, but binding of yeast cells is not mediated by sialoadhesin because (i) erythrocytes did not block yeast cell binding, (ii) yeast cell adherence was unaffected by sialoadhesin-specific monoclonal antibodies, (iii) the purified sialoadhesin did not bind to yeast cells, and (iv) an Fc-sialoadhesin chimera immobilized on plastic did not bind yeast cells. These data give further support for a unique macrophage adhesion system that binds C.

Coping by individuals with physical disabilities with perceived challenge in physical activity: are people consistent?

This study examined coping and affective experience to perceived challenge in physical activity settings in 30 individuals with physical disabilities in three separate situations over 6 months. On every occasion, each individual was asked to report the most challenging physical activity of the preceding week and indicate how he or she coped with the challenge and what affective states were experienced. Coping was measured using a modification of Carver, Scheier, and Weintraub's (1989) COPE inventory.

The effects of calcium site occupancy and reagent length on reactivity of calmodulin lysyl residues with heterobifunctional aryl azides. Mapping interaction domains with specific calmodulin photoprobe derivatives.

The relationship of structural and functional moieties on calmodulin is important in all venues of cell activity. In this study, we investigate the effect of lysine modification on calmodulin function. Azidosalicylate reagents containing different "linker arm" lengths, between the photoactive terminus and an amine-reactive N-hydroxysuccinimidyl ester moiety were used to modify calmodulin lysines at three different positions in a calcium-dependent manner.

Prediction of response to lithotripsy--the use of scanning electron microscopy and X-ray energy dispersive spectroscopy.

A single urine sample was obtained from each of 38 patients before and immediately after treatment with a Wolf Piezolith 2300. Each sample was analysed for crystals using scanning electron microscopy and X-ray energy dispersive spectroscopy. In all cases it was possible to make a stone diagnosis prior to treatment and there was 100% correlation between the pre- and post-treatment diagnosis.

Sialoadhesin on macrophages: its identification as a lymphocyte adhesion molecule.

In this study we present evidence that the mouse and rat sialoadhesin (originally named sheep erythrocyte receptor) on macrophages can function as a lymphocyte adhesion molecule. Lymphocytes were shown to bind to the splenic marginal zone, and lymph node subcapsular sinus and medulla in a frozen section assay. Selective depletion experiments showed that binding was mediated by macrophages.

Encrustation of intraprostatic stents--a comparative study.

Metallic stents have been used in the management of prostatic disease in patients unfit for surgery. A variety of stents have become available but the optimum design and metal of construction has not yet been defined. This study examined one of the potential complications of stent insertion by demonstrating that they are susceptible to encrustation.

Application of an N-(4-azido-2,3,5,6-tetrafluorobenzoyl)tyrosine-substituted peptide as a heterobifunctional cross-linking agent in a study of protein O-glycosylation in yeast.

In order to investigate the O-mannosyltransferase involved in the initial O-mannosylation of glycoproteins in Saccharomyces cerevisiae, a photoactive hexapeptide, [125I]-N-(4-azido-2,3,5,6-tetrafluorobenzoyl)-3-iodo-Tyr-Asn-Pro-T hr-Ser-Val ([125I]azidoTyr-peptide), was synthesized by solid-phase techniques using a new photoactive cross-linking reagent, N-(4-azido-2,3,5,6-tetrafluorobenzoyl)tyrosine, and resin-bound Asn-Pro-Thr(tBu)-Ser(tBu)-Val. When this modified hexapeptide substrate was incubated with O-mannosyltransferase preparations, the hexapeptide was an acceptor of [14C]-mannose from dolichol phosphate-[14C]mannose. After partially purifying the O-mannosyltransferase and photolabeling these enzyme preparations with [125I]azidoTyr-peptide, a ca.