Correlation between binding activity, inhibition of lymphoblastic transformation and metabolism of tixocortol 21 pivalate in mouse thymocytes

1987 ◽  
Vol 21 (3-4) ◽  
pp. 262-265
Author(s):  
V. Lelièvre ◽  
B. Bertin ◽  
F. Chanoine ◽  
J. Buré ◽  
J. L. Junien
Author(s):  
T. Mullin ◽  
G. Yee ◽  
M. Aheam ◽  
J. Trujillo

There have been numerous reports in the current literature suggesting that hematopoietic precursor cells in some human chronic myelocytic leukemias (CML) undergo lymphoblastic transformation at the time of the acute blast crisis (BC) stage. The primary evidence offered in support of this transformation theory--lymphoblastic appearing morphology, increased terminal deoxynucleotidyl transferase (TdT) activity, and chemotherapeutic sensitivity to vincristine and prednisone--has been indirect, however, since these features may occur in nonlymphoid cells. More direct support for the Pre-B lineage of these cells has recently been provided by immunofluorescent light microscopic studies demonstrating the presence of intracytoplasmic immunoglobulin M (IgM) in these CML-BC cells.


2002 ◽  
Vol 69 ◽  
pp. 59-72 ◽  
Author(s):  
Kurt Drickamer ◽  
Andrew J. Fadden

Many biological effects of complex carbohydrates are mediated by lectins that contain discrete carbohydrate-recognition domains. At least seven structurally distinct families of carbohydrate-recognition domains are found in lectins that are involved in intracellular trafficking, cell adhesion, cell–cell signalling, glycoprotein turnover and innate immunity. Genome-wide analysis of potential carbohydrate-binding domains is now possible. Two classes of intracellular lectins involved in glycoprotein trafficking are present in yeast, model invertebrates and vertebrates, and two other classes are present in vertebrates only. At the cell surface, calcium-dependent (C-type) lectins and galectins are found in model invertebrates and vertebrates, but not in yeast; immunoglobulin superfamily (I-type) lectins are only found in vertebrates. The evolutionary appearance of different classes of sugar-binding protein modules parallels a development towards more complex oligosaccharides that provide increased opportunities for specific recognition phenomena. An overall picture of the lectins present in humans can now be proposed. Based on our knowledge of the structures of several of the C-type carbohydrate-recognition domains, it is possible to suggest ligand-binding activity that may be associated with novel C-type lectin-like domains identified in a systematic screen of the human genome. Further analysis of the sequences of proteins containing these domains can be used as a basis for proposing potential biological functions.


1991 ◽  
Vol 66 (03) ◽  
pp. 310-314 ◽  
Author(s):  
David C Sane ◽  
Tammy L Moser ◽  
Charles S Greenberg

SummaryVitronectin (VN) stabilizes plasminogen activator inhibitor type 1 (PAI-1) activity and prevents the fibrin(ogen)-induced acceleration of plasminogen activation by t-PA. These antifibrinolytic activities as well as other functions are mediated by the glycosaminoglycan (GAG) binding domain of VN. Since the GAG binding region is rich in arginyl and lysyl residues, it is a potential target for enzymes such as plasmin. In this paper, the dose and time-dependent proteolysis of VN by plasmin is demonstrated. The addition of urokinase or streptokinase (200 units/ml) to plasma also produced proteolysis of VN. With minimal proteolysis, the 75 kDa band was degraded to a 62-65 kDa form of VN. This minimal proteolysis destroyed the binding of [3H]-heparin to VN and reversed the neutralization of heparin by VN.Thus, the plasmin-mediated proteolysis of the GAG binding activity of VN could destroy the antifibrinolytic activity of VN during physiologic conditions and during thrombolytic therapy. Furthermore, other functions of VN in complement and coagulation systems that are mediated by the GAG binding domain may be destroyed by plasmin proteolysis.


1992 ◽  
Vol 68 (04) ◽  
pp. 464-469 ◽  
Author(s):  
Y Fujimura ◽  
S Miyata ◽  
S Nishida ◽  
S Miura ◽  
M Kaneda ◽  
...  

SummaryWe have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca2+-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957–64).Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an “activated complex” formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GPIb, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.


1997 ◽  
Vol 78 (02) ◽  
pp. 930-933 ◽  
Author(s):  
Ping Chang ◽  
D L Aronson

SummaryFive plasma preparations (11 lots) used in the treatment of von Willebrand’s disease (vWD) were evaluated. The collagen binding function of von Willebrand factor (vWF) containing preparations was compared with the ristocetin cofactor activity and the vWF antigen. Some preparations have higher ratio of functional activity (ristocetin cofactor and collagen binding) relative to the antigen than is found in normal plasma. The ristocetin cofactor activity and the collagen binding activity are tightly correlated (r = .95). Ultracentrifugal (UCF) analysis was used to compare the size distribution of vWf antigen, ristocetin cofactor and collagen binding activity. The sedimentation of all of the vWF parameters in the plasma products was slower than in plasma. In plasma products the ristocetin cofactor activity sediments the most rapidly, the collagen binding activity is slower and the antigen the slowest. The collagen/antigen ratio decreases with decreasing vWF size. Assignment of potency to vWF containing preparations utilizing the collagen binding activity may be more precise and as accurate as with the traditional ristocetin cofactor assay.


1969 ◽  
Vol 62 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Jeanine Guidollet ◽  
Pierre Louisot

ABSTRACT Corticosteroid-binding activity (transcortin) was investigated at the subcellular level of the rat liver cell: it was located exclusively in the cell sap, and not on the ribosomes or membranes. Oestrogens were found to increase the biological activity of this glycoprotein (corticosterone binding) in the plasma and in the cell sap. The isotopic activity of the glucidic fragments of glycoprotein (after incorporation of 14C-D-glucosamine), however, remained constant or decreased in the specific subcellular sites at which they were incorporated (membranes and cell sap). This absence of correlation between these two results is not in agreement with an induction of transcortin synthesis by oestrogens, but in favour of an activation of normally masked molecular sites.


Author(s):  
Khvorova L.S. ◽  
Byzov V.A.

The article is devoted to the creation of a carbohydrate product with rosehip extract in the form of sweets (glucose Fudge) with a therapeutic and preventive effect aimed at restoring the body of people exposed to intense physical and mental stress and the effects of damaging environmental factors. As carbohydrates in the recipe, simple carbohydrates (glucose) and complex carbohydrates in the form of starch molasses containing (maltose, tri - Tetra - sugars, dextrins) are used. Glucose in the formulation is the main energy ingredient, sweetener and structure-forming component that gives the product a solid consistency due to crystallization. The medicinal effect of the product is provided by rosehip extract. Numerous published studies have established its vitamin, immunostimulating and antioxidant activity, inhibition of uric acid formation and obesity, which are associated with flavonoids, other phenolic compounds, and vitamins. The list of medicinal properties of rosehip extract shows the feasibility of using it in additional nutrition of people in order to prevent diseases. For the formulation of our sweets, the extraction of crushed rosehip fruits was carried out three times with hot water at a temperature of 65-700C, followed by concentration of the extract under vacuum to 25-30% SV. The resulting extract-concentrate was introduced into the formulation in a dosage of 5.5% SV per 100 g of SV glucose Fudge, which provided the necessary dosage for the product when used from 3 (for children) to 10 sweets a day (for adults) for the prevention of colds.


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