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H Gralnick

Publications and source records attributed to H Gralnick.

15 recordsLinked to original sources
PubMed2000

A preliminary analysis of platelet von Willebrand factor oligosaccharides.

Little is known about the carbohydrate structure of the platelet von Willebrand factor (vWf). We have analyzed N-linked oligosaccharides from both plasma and platelet vWf by Fluorophore-Assisted-Carbohydrate Electrophoresis (FACE) and isoelectric focusing before and after digestion of the proteins with neuraminidase. We observed a greater variety of N-linked oligosaccharides derived from plasma vWf than from platelet vWf. Neuraminidase treatment reduced the oligosaccharides from both proteins to only two or three bands and produced significant increases in their isoelectric points.

Blood Platelets↗
PubMed1994

Platelet adhesion to collagen in individuals lacking glycoprotein IV.

The Naka isoantigen is expressed on glycoprotein (GP) IV (CD36), a platelet membrane GP that has been identified as having a role in platelet interactions with collagen and thrombospondin and in binding Plasmodium falciparum-infected erythrocytes to endothelial cells and melanoma cells. We have studied normal platelets and Naka- platelets from two Japanese donors that have 1% of GPIV by concentration-dependent antibody binding and flow cytometry. We studied the adherence of normal and Naka- platelets to types I, III, and IV collagen in static and to type I collagen in flowing systems at high shear force. We have also studied aggregation of normal and Naka- platelets to type I collagen. Naka- platelets showed normal or increased aggregation to type I collagen and normal adhesion to types I, III, and IV collagen in the presence of Mg++ or EDTA. Platelet aggregation and adhesion were inhibited by the anti-alpha 2 beta 1 antibody 176D7 to the same extent in Naka- as in normal platelets. We also studied endogenous thrombospondin surface expression and found that thrombin-stimulated Naka- platelets expressed the same amount of thrombospondin as did normal platelets. From our studies with Naka- platelets, we cannot identify a definitive role for GPIV in platelet aggregation, in adhesion to types I, III, and IV collagen, or in endogenous thrombospondin binding to platelets.

Antigens, CD↗
PubMed1994

The chronic myeloid leukaemias: guidelines for distinguishing chronic granulocytic, atypical chronic myeloid, and chronic myelomonocytic leukaemia. Proposals by the French-American-British Cooperative Leukaemia Group.

We have reviewed our experience with four of the entities that are included under the generic term chronic myeloid leukaemia (CML), namely the classic Ph+ CGL, both BCR+ and BCR-, aCML and CMML. We have developed a statistical model that confirms that CGL, aCML and CMML can be distinguished from each other with reasonable success employing five quantitative parameters (WBC, percentage immature granulocytes, percentage monocytes, percentage basophils, percentage erythroid precursors in bone marrow) and one qualitative parameter (granulocytic dysplasia). It is hoped that these detailed recommendations will enable investigators to improve their diagnostic accuracy. This should permit more uniform comparisons of molecular biologic and clinical studies.

Bone Marrow↗
PubMed1994

Glycoprotein Ia-IIa (VLA-2) and glycoprotein Ib-IX complexes are processed independently during thrombin-induced platelet activation.

We have previously shown that when human platelets are stimulated by thrombin, glycoprotein Ib-IX (GP Ib-IX) complexes are cleared to the surface-connected canalicular system (Blood 1990;76:1503). The question arose as to whether GP Ia-IIa complexes (VLA-2), another adhesion receptor thought to be linked to the membrane cytoskeleton, behaved similarly. Monoclonal antibodies to GP Ia-IIa were used in either (1) immunofluorescence procedures and flow cytometry or (2) immunogold staining and electron microscopy. In flow cytometry, VLA-2 was shown to have a low but variable expression in the platelets of different donors. Immunogold staining showed that the complexes were regularly distributed over the platelet surface. This was best seen after staining of paraformaldehyde-fixed whole mounts, where bound antibodies were often visualized in small clusters. The surface expression of VLA-2 receptors increased somewhat after thrombin stimulation, the receptors coming from a small intracellular pool revealed by flow cytometric analysis of Triton X-100-permeabilized cells. Immunogold staining showed that after activation the receptors were equally as present on pseudopods as on the peripheral zone of the platelet. Down-regulation, as seen with GP Ib-IX complexes, was not observed. Our results therefore show that two-way trafficking of adhesion receptors can occur during platelet activation. This would imply that GP Ib-IX and VLA-2 are attached to different elements within the membrane cytoskeleton.

Blood Platelets↗
PubMed1994

Nomenclature of quantities and units in thrombosis and haemostasis (recommendation 1993). A Collaborative project of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH/SSC) and the Commission/Committee on Quantities and Units (in Clinical Chemistry) of the International Union of Pure and Applied Chemistry-International Federation of Clinical Chemistry (IUPAC-IFCC/CQU(CC)).

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Blood Proteins↗
PubMed1991

Plasticity of integrin expression by nerve-derived connective tissue cells. Human Schwann cells, perineurial cells, and fibroblasts express markedly different patterns of beta 1 integrins during nerve development, neoplasia, and in vitro.

Strikingly selective expression patterns of beta 1, alpha 2, alpha 3, and alpha 5 integrin subunits were revealed in endoneurium, perineurium, and epineurium of fetal and adult human peripheral nerve by immunostaining with specific antibodies. The alpha 2 subunit was expressed only on Schwann cells both in fetal and adult nerve, whereas the alpha 3 epitopes were expressed exclusively in the adult tissue and were primarily present on perineurial cells. The alpha 5 epitopes were expressed only on the innermost cell layer of perineurium of fetal and adult nerve. The tumor cells within schwannomas and cutaneous neurofibromas expressed both alpha 2 and alpha 3 subunits, indicating that Schwann cells have the potential to express also the alpha 3 subunit in vivo. Cell cultures established from human fetal nerve and neurofibromas revealed expression of the alpha 2 and alpha 5 epitopes on Schwann cells, perineurial cells, and fibroblasts, whereas only Schwann cells contained the alpha 3 epitopes which were occasionally concentrated on the adjacent Schwann cells at cell-cell contacts. Our findings emphasize that nerve connective tissue cells change their profiles for expression of extracellular matrix receptors under conditions which have different regulatory control signals exerted by, for example, axons, humoral factors, or the extracellular matrix of the peripheral nerve. This plasticity may play an important role during nerve development and in neoplastic processes affecting the connective tissue compartments of peripheral nerve.

Antibodies, Monoclonal↗
PubMed1990

Monoclonal antibody and synthetic peptide inhibitors of human tumor cell migration.

The processes of migration and invasion by human tumor cells are likely to involve specific cell surface receptors, such as receptors for the extracellular matrix molecules fibronectin, laminin, and collagen. We have examined the roles of several of these receptors using a set of monoclonal antibodies directed against the beta 1 integrin family, as well as a series of synthetic peptides reported to inhibit various interactions of each of these proteins with the cell surface. The most general inhibitor of tumor cell migration was found to be the anti-beta 1 monoclonal antibody 13, which inhibited the migration of human HT-1080 fibrosarcoma cells, 5637 bladder carcinoma cells, VA13 viral transformants, and HCT 116 colon carcinoma cells when fibronectin was the migration substrate. Moreover, this antibody was particularly effective in blocking cell migration on laminin, as well as migration within 3-dimensional collagen gels. It also inhibited in vitro invasiveness in a reconstituted basement membrane invasion assay (Matrigel assay) at concentrations as low as 1 microgram/ml. Integrins of the beta 1 class thus appear to play a central role in several types of migration by a variety of human tumor cell lines. Anti-alpha 5 fibronectin receptor monoclonal antibody 16 also significantly inhibited migration on fibronectin, but not on other substrates, in 3 of the 4 cell lines. Conversely, anti-alpha 2 monoclonal antibody F17 strikingly inhibited migration in 3-dimensional collagen gels, but not on other substrates, implicating the alpha 2 beta 1 integrin system in migration of tumor cells within collagenous matrices. A series of synthetic peptides previously reported to inhibit interactions of normal cells with fibronectin, laminin, and collagen were also tested as inhibitors of tumor cell migration. Peptides containing the Arg-Gly-Asp adhesive recognition signal were partially inhibitory, but with occasional exceptions, most other peptides had no effects on migration. Our results indicate the central importance of several specific beta 1 integrins in human tumor cell migration and show the effectiveness of monoclonal antibody treatment in blocking this process in vitro.

Amino Acid Sequence↗
PubMed1989

Diffuse osteosclerosis in hairy cell leukemia.

We describe two patients with a new clinical pathologic syndrome of diffuse osteosclerosis in association with hairy cell leukemia. In both patients bone marrow biopsies could not be obtained due to extremely hard bones and inability to insert the biopsy needle; neither patient had a history of bony pain or fracture. The osteosclerotic process in one patient stabilized after successful treatment of her hairy cell leukemia with interferon alpha and deoxycoformycin suggesting that the osteosclerosis observed was related to the underlying malignant disease. Possible etiologic mechanisms are discussed.

Adult↗
PubMed1989

Localization of integrin receptors for fibronectin, collagen, and laminin in human skin. Variable expression in basal and squamous cell carcinomas.

VLA integrins in human skin were examined by indirect immunofluorescence utilizing antibodies recognizing the beta 1, alpha 2, alpha 3, or alpha 5 subunits. Staining of fetal, newborn, or adult skin with antibodies to beta 1, alpha 2, or alpha 3 subunits gave essentially similar staining patterns: intense staining was associated with the basal layer of the epidermis, hair follicles, and blood vessel walls. The alpha 5 subunit could be detected only in epidermis and the inner root sheath of hair follicles in fetal skin. In epidermis, the staining reaction for the beta 1 subunit was not only found in sites interfacing with the basement membrane zone, but also around the entire periphery of these cells. We speculate that these receptors might have previously unrecognized functions in cell-cell interactions or that these findings may suggest the presence of previously unrecognized ligands in the intercellular spaces of keratinocytes. Examination of nine nodular basal cell carcinomas revealed a prominent staining reaction with anti-beta 1 and anti-alpha 3 antibodies at the periphery of the tumor islands. In contrast, staining of five squamous cell carcinomas revealed either the absence of integrins or altered and variable expression. Thus, matrix components and their receptors may participate in modulation of growth, development, and organization of human skin.

Adult↗
PubMed1988

Rearrangement of both immunoglobulin and T-cell receptor genes in a prolymphocytic variant of hairy cell leukemia patient resistant to interferon-alpha.

We describe a patient with the so-called "prolymphocytic variant" form of hairy cell leukemia (HCL) resistant to treatment with interferon-alpha (IFN-alpha). Analysis of immunoglobulin (Ig) and T-cell receptor-beta (TCR beta) gene rearrangements from serial peripheral blood mononuclear cell specimens (MNCs) confirmed not only the B-cell nature of the disease, but also the subsequent emergence of a morphologically indistinguishable population of cells with a clonal TCR beta rearrangement in addition to the original Ig gene rearrangement. With the exception of a transient increase in peripheral blood T cells during treatment with deoxycoformycin (DCF), the MNCs remained essentially constant throughout therapy with no evidence of a co-existing T-cell clone to account for the TCR beta rearrangement. Although MNCs from this patient bound significantly less IFN-alpha than did MNCs from other HCL patients, the binding was of high affinity with a kd similar to that of control cells. The number of IFN-gamma receptors on our patient's MNCs was four times higher than the number of IFN-alpha receptors and was similar to the number of IFN-alpha receptors on MNCs from HCL patients responsive to IFN-alpha. While various treatments including IFN-alpha, DCF, chlorambucil, splenectomy, leukopheresis, and IFN-gamma were not able to change the clinical progression of the disease, they may have provided an opportunity for the divergent TCR beta rearranged clone to expand and displace the initially dominant clone.

Aged↗
PubMed1987

Inhibition of von Willebrand factor binding to platelets by two recognition site peptides: the pentadecapeptide of the carboxy terminus of the fibrinogen gamma chain and the tetrapeptide arg-gly-asp-ser.

When platelets are stimulated by thrombin or ADP, von Willebrand factor (vWf) binds to the platelet glycoprotein IIb/IIIa (GPIIb/IIIa). Two recognition sites for vWf binding have been identified on the GPIIb/IIIa. One is a tetrapeptide, arg-gly-asp-ser (RGDS), and the second is a dodecapeptide with the sequence HHLGGAKQAGDV. We used these purified peptides to analyze the recognition specificities for the platelet binding of vWf. The RGDS and the pentadecapeptide totally inhibited 125I-vWf in a dose-dependent manner. The IC50 was 8 microM for the RGDS and 40 microM for the pentadecapeptide. These results indicate that the RGDS binds with higher affinity to a vWf binding site on GPIIb/IIIa than does the pentadecapeptide site. When the two peptides were incubated together, they augmented the inhibition of vWf binding. These data support the evidence that the GPIIb/IIIa has two distinct binding sites for vWf binding. The RGDS site appears to have a higher affinity for the vWf binding site than does the pentadecapeptide site.

Adenosine Diphosphate↗
PubMed1980

Physiologic manifestations of human anaphylaxis.

In the course of a controlled study to evaluate different forms of immunotherapy for subjects with insect-sting hypersensitivity, we observed 11 subjects who had systemic cutaneous urticarial reactions and 3 subjects who experienced systemic anaphylaxis. With the exception of tachycardia, there were no cardiopulmonary changes in the subjects with urticaria, whereas the major manifestation of anaphylactic shock in the other three subjects was severe hypotension that was probably secondary to peripheral vasodilation. Significant abnormalities in gas exchange developed in two subjects. In one, bronchospasm precipitated a respiratory arrest followed by endotracheal intubation with mechanical ventilation. Although plasma histamine levels were not related to the development of cutaneous reactions, the plasma histamine levels correlated with the severity and duration of the cardiopulmonary changes observed during anaphylactic shock. The two subjects with the most severe shock showed evidence of intravascular coagulation characterized by a diminution of Factor V, Factor VIII, fibrinogen, and high molecular weight kininogen, as well as changes in components of the complement system. Standard therapy with epinephrine and fluids, usually recommended for the treatment of systemic anaphylaxis, did not immediately reverse either the hemodynamic or the respiratory abnormalities in the two subjects with the most severe anaphylactic shock. Hemodynamic recovery was gradual and did not seem directly related to any specific therapeutic intervention.

Anaphylaxis↗
PubMed1976

Fourteen-year remission of acute leukemia in a patient exposed to thorotrast.

A case report of a patient who developed acute myelogenous leukemia 15 years after injection of Thorotrast and who has been in a sustained long term remission for 14 years is presented with a review of the problems associated with Thorotrast, subsequently shown to be radioactive with long term sequelae.

Adolescent↗