bluuebunny/crossref_metadata_2025_split huggingface dataset:
A qualitative and quantitative analysis of the activation and inactivation of protein C in vivo in a primate model
Authors: Hoogendoorn H , Nesheim ME , Giles AR 
Published: October 2019

Abstract
A model of Protein C (PC) activation in vivo was used to investigate the complexing of activated PC (APC) with its plasma inhibitors, PC inhibitor (PCI) and alpha 1-antitrypsin (alpha 1AT). Chimpanzees were infused with a bolus of activated factor X (F.Xa) together with vesicles of phosphatidylcholine and phosphatidylserine (PCPS). Pre- and post-infusion plasma samples were analyzed using enzyme linked immunosorbent based assays (ELISA) for PC and APC complexes, and immunoblotting of PC from nondenaturing polyacrylamide gel electrophoresis. Within 2 minutes of infusion, a 60% decrease in nonactivated PC zymogen (PCz) levels was observed. This coincided with a precipitous drop in plasma activities of cofactors VIIIa and Va. In contrast, total PC antigen (PCt) levels decreased by only 1%, indicating APC generation. Complexes of APC with both PCI and alpha 1AT were observed on immunoblots, and further identified and quantified using a sandwich ELISA employing antibodies to both PC and these inhibitors. The distribution of APC between these two inhibitors varied with the dose of F.Xa/PCPS infused. At a dose of F.Xa/PCPS of 24.05 pmol and 37.70 nmol/kg, respectively, an initial spike of APC generation, associated with decreases in the levels of factors VIIIa and Va, was noted but dissipated over the next 30 minutes. During this period, APC/inhibitor complexes appeared with the levels of APC-PCI and APC-alpha 1AT reaching 8.5 nmol/L and 2.2 nmol/L by 30 minutes, respectively. In contrast, at a higher dose of F.Xa/PCPS of 36.60 pmol and 56.30 nmol/Kg respectively, complexes of APC-alpha 1AT appeared rapidly and reached a level of 6 nmol/L by 30 minutes postinfusion, whereas APC-PCI complexes were only present at a concentration of 3.4 nmol/L by this time. Additional experiments with lower doses of F.Xa/PCPS suggest that PCI is the preferred inhibitor of APC, but as the availability of this inhibitor becomes limiting, alpha 1AT plays an increasingly crucial role as a secondary inhibitor of endogenously generated APC. Moreover, evidence is presented suggesting the existence of additional inhibitor(s) of APC that may have a role similar to alpha 1AT.
Degranulating mast cells secrete an endoglycosidase that degrades heparan sulfate in subendothelial extracellular matrix
Authors: Bashkin P , Razin E , Eldor A , Vlodavsky I 
Published: October 2019

Abstract
Mast cells are widely distributed in perivascular connective tissues, especially in areas of active tumor growth and vascular reactivity. Incubation of metabolically [35S]O4 = -labeled subendothelial extracellular matrix (ECM) with lysates of bone marrow-derived mouse mast cells (BMMC) resulted in extensive degradation of heparan sulfate (HS) into fragments 5 to 6 times smaller than intact HS side chains. A much lower activity (seven- to eightfold) was expressed by intact BMMC incubated in contact with the ECM. These fragments were not produced in the presence of heparin, were sensitive to deamination with nitrous acid, and resistant to further degradation with papain or chondroitinase ABC. These results indicate that an endoglycosidase (heparanase) is involved in BMMC-mediated degradation of HS in the subendothelial ECM. Heparanase activity was not detected in medium conditioned by cultured BMMC, or in lysates of Ableson transformed BMMC and rat basophilic leukemic (RBL) cells. Both heparanase and beta- hexosaminidase, a mast cell granule enzyme, were released on degranulation of BMMC induced by the calcium ionophore A23187, or by exposure to IgE-Ag, suggesting that heparanase is localized in the cell granules. Under these conditions, less than 5% of the cellular content of lactate dehydrogenase were released. Degradation of the ECM-HS by the mast cell heparanase and the associated release of HS-bound endothelial cell growth factors that are stored in ECM (Vlodavsky et al, Proc Natl Acad Sci USA 84:2292, 1987; Bashkin et al, Biochemistry 28:1737, 1989) may play a role in the proposed mast cell-mediated stimulation of neovascularization.
Glycophorin C content of human erythrocyte membrane is regulated by protein 4.1
Authors: Reid ME , Takakuwa Y , Conboy J , Tchernia G , Mohandas N 
Published: October 2019

Abstract
Human erythrocyte transmembrane sialoglycoprotein, glycophorin C, plays a functionally important role in maintaining erythrocyte shape and regulating membrane material properties, possibly through its interaction with protein 4.1. Moreover, it has previously been shown that membranes deficient in protein 4.1 exhibit decreased content of glycophorin C. To further define the relationship between protein 4.1 and glycophorin C, a series of studies were performed using both protein 4.1- and glycophorin C-deficient erythrocytes. Quantitation by flow cytometry showed that the glycophorin C content of cells totally deficient in protein 4.1 was 9% of normal and that of cells partially deficient in protein 4.1 was 44% of normal. Interestingly, while homozygous glycophorin C-deficient cells had no detectable levels of this sialoglycoprotein, cells from obligate heterozygotes had normal levels. Protein 4.1 content of membranes of these glycophorin C- deficient cells was also normal. These data suggest that glycophorin C may be synthesized in excess by erythroid cells and its membrane content regulated by protein 4.1. To investigate if this regulation is due to association between protein 4.1 and glycophorin C, we examined the retention of glycophorin C in membrane skeletons (Triton shells) prepared from normal membranes, protein 4.1-deficient membranes, and protein 4.1-deficient membranes reconstituted with exogenous protein 4.1. Glycophorin C is retained by Triton shells prepared from normal membranes, whereas Triton shells prepared from protein 4.1-deficient membranes are totally devoid of this sialoglycoprotein. However, reconstitution of protein 4.1-deficient membranes with purified protein 4.1 resulted in retention of glycophorin C with the Triton shells. This finding suggests that protein 4.1 is necessary for association of glycophorin C with the membrane skeleton. Furthermore, these data suggest that through its interaction with glycophorin C, protein 4.1 may play a role in regulating the membrane content of this sialoglycoprotein in mature human erythrocytes.
Anti-leukemia potential of interleukin-2 activated natural killer cells after bone marrow transplantation for chronic myelogenous leukemia
Authors: Hauch M , Gazzola MV , Small T , Bordignon C , Barnett L , Cunningham I , Castro- Malaspinia H , O'Reilly RJ , Keever CA 
Published: October 2019

Abstract
The anti-leukemia potential of natural killer (NK) cells has been evaluated in 40 patients transplanted for chronic myelogenous leukemia (CML) to determine whether differences in NK cell function were correlated with subsequent leukemic relapse. Cells from patients and their donors were tested in 51Cr release assays against fully allogeneic CML targets and against cultured K562 targets; cells from 26 patients were tested against host-derived CML targets that were cryopreserved before transplantation. Cultured CML targets (K562) were highly susceptible to lysis by freshly isolated peripheral blood lymphocytes (PBL) and to a greater degree by PBL cultured in medium containing interleukin-2 (IL-2) in all assays performed. In contrast, noncultured CML targets were lysed only by IL-2-activated cells from a subset of patients. When present, lytic activity to CML targets was detectable as early as 3 weeks after bone marrow transplantation, and remained positive throughout the posttransplant period. Optimal lytic activity developed within the first week of culture and required greater than or equal to 250 U/mL of IL-2 in the culture medium. Lytic activity to fully allogeneic and host-derived CML targets appeared to be mediated by CD16+ and CD56+ cells but not by CD3+ cells. Lysis of allogeneic CML targets was variable, but patients could be divided into two groups: those with and those without lytic activity to the majority of targets tested. The basis for the differences in lytic activity could not be ascribed to target susceptibility to lysis, the proportion of NK cells in the cultures, or to the phenotype of the NK cell subsets in the cultures. When tested in parallel, the lytic activity of donor and recipient cultures against host-derived CML targets was highly correlated, suggesting that there may be inherent differences in the ability of NK cells to recognize CML targets. The risk of relapse for patients who failed to generate lytic activity against host-derived CML targets was significantly increased over that for patients with lytic activity against host leukemia. These data indicate that posttransplant immunotherapy with IL-2 designed to activate NK cells will likely augment the graft-versus-leukemia potential of the graft.
Polymorphism of human platelet membrane glycoprotein IIb associated with the Baka/Bakb alloantigen system
Authors: Lyman S , Aster RH , Visentin GP , Newman PJ 
Published: October 2019

Abstract
The human Baka/Bakb alloantigen system has been implicated in the pathogenesis of post-transfusion purpura and neonatal alloimmune thrombocytopenic purpura. Human alloantisera specific for either the Baka or Bakb allele have been shown to react exclusively with the heavy chain of membrane glycoprotein (GP) IIb. To investigate the structure of the Bak epitopes, we used the polymerase chain reaction (PCR) to amplify GPIIb cDNA synthesized from platelet RNA samples prepared from individuals of known serologic phenotype. Subsequent DNA sequence analysis of amplified GPIIb cDNAs derived from one Baka homozygous individual and one Bakb homozygous individual revealed a single nucleotide base difference near the 3′ end of the mRNA encoding the GPIIb heavy chain. Short 13 base allele-specific oligonucleotides (ASO) containing the putative phenotype-specific base in the middle were then synthesized, end-labeled with digoxigenin-11-dUTP using terminal transferase, and used as probes in subsequent dot-blot hybridization experiments. Platelet RNA was prepared from a panel made up of four Baka/a, three Bakb/b, and two Baka/b individuals, and the mRNA encoding GPIIb was amplified using PCR and spotted onto nylon membranes. ASO hybridization showed that the nucleotide base difference identified above segregated with Bak phenotype in all nine individuals examined (P = .002). The base pair substitution results in an amino acid polymorphism at residue 843 of the mature heavy chain. The Baka form of GPIIb encodes an isoleucine at this position, whereas the Bakb allele contains a serine. Identification of the polymorphism associated with this clinically important alloantigen system should permit new therapeutic and diagnostic approaches for treating and managing patients with alloimmune thrombocytopenic disorders.
Evidence that an abnormality in the glycoprotein Ib alpha gene is not the cause of abnormal platelet function in a family with classic Bernard-Soulier disease
Authors: Finch CN , Miller JL , Lyle VA , Handin RI 
Published: October 2019

Abstract
The underlying molecular basis for Bernard-Soulier Disease (BSD) is currently unknown. Platelets from patients with this autosomal recessive bleeding disorder have multiple abnormalities, including a markedly reduced von Willebrand factor-dependent adhesiveness due to a deficiency of the platelet membrane glycoprotein (GP) Ib/IX complex. In the present studies, we have used an intragenic restriction fragment length polymorphism (RFLP) for Taq I in the GPIb alpha gene to study linkage between this gene and the inheritance of BSD in a family with two affected siblings. Whereas the proband was heterozygous, showing both the 0.7 and 4.0 kb bands of this polymorphism (A/B), her affected brother was homozygous for the 0.7 kb band (A/A). Accordingly, these siblings did not inherit the same pair of GPIb alpha alleles from their parents. Additionally, one child of the proband was A/A, while the second studied child was A/B, with neither showing any evidence of BSD. No construct of heterozygosity or homozygosity for GPIb alpha alleles in this family is consistent with a model in which one or more defective GPIb alpha alleles could produce BSD. RFLP analysis with BamHI or HindIII showed entirely normal patterns in the patients, indicating the absence of any gross deletion of the GPIb alpha gene. GPIb alpha mRNA from patient platelets was reverse transcribed and subsequently amplified by the polymerase chain reaction, demonstrating the presence of GPIb alpha transcript. Furthermore, trace amounts of GPIb could be shown on the surface of patient platelets. Based on these results, a defect in the GPIb alpha gene is unlikely to be the cause of BSD in this family.
Risk factors for chronic graft-versus-host disease after HLA-identical sibling bone marrow transplantation
Authors: Atkinson K , Horowitz MM , Gale RP , van Bekkum DW , Gluckman E , Good RA , Jacobsen N , Kolb HJ , Rimm AA , Ringden O 
Published: October 2019

Abstract
Chronic graft-versus-host disease (GVHD) is an important complication of bone marrow transplantation. We analyzed risk factors for chronic GVHD in 2,534 recipients of HLA-identical sibling transplants surviving at least 90 days after transplantation. The actuarial probability of developing chronic GVHD within three years posttransplant was 46% +/- 3% (95% confidence interval). The most important risk factor for chronic GVHD was acute GVHD. The 3-year probabilities of chronic GVHD were 28% +/- 3%, 49% +/- 5%, 59% +/- 6%, 80% +/- 9%, and 85% +/- 15% for persons with grades 0, I, II, III, and IV acute GVHD, respectively (P less than .0001). Among patients with no or grade I acute GVHD, recipient age greater than 20 years, use of non-T-cell depleted bone marrow, and alloimmune female donors for male recipients predicted a higher risk of chronic GVHD. When all three adverse risk factors were present, the probability of chronic GVHD was 62% among persons with no prior acute GVHD and 85% among those with grade I acute GVHD. Among patients with grade II through IV acute GVHD, no other risk factor predicted chronic GVHD. These data identify individuals who might benefit from treatment strategies aimed at changing the incidence of chronic GVHD.
Fetal expression of hemonectin: an extracellular matrix hematopoietic cytoadhesion molecule
Authors: Peters C , O'Shea KS , Campbell AD , Wicha MS , Long MW 
Published: October 2019

Abstract
Hemonectin, a component of bone marrow extracellular matrix, is a lineage- and organ-specific attachment molecule for cells of the granulocytic lineage. We hypothesized that hemonectin is an important marker of fetal granulopoiesis that is developmentally regulated during the ontogeny of the hematopoietic system. Murine hematopoiesis originates in the yolk sac and subsequently appears in the liver, spleen, and bone marrow. Using an affinity-purified polyclonal antibody to purified hemonectin as a probe of developing hematopoietic organs, we observe that hemonectin is coordinately expressed at developmental stages of the mouse in those tissues that are supporting hematopoiesis. Multiparameter flow cytometric analysis reveals that approximately 7% of fetal liver cells express hemonectin by day 13 of gestation, and that 32% of the cells are positive by day 19. Additionally, restricted hemonectin expression is noted in other tissues (cartilage, skin, developing bone, and capillary endothelial cells), suggesting that this molecule subserves other developmental functions and/or belongs to a previously unrecognized family of molecules.
Effects of interleukin-3 and interleukin-4 on the development of "connective tissue-type" mast cells: interleukin-3 supports their survival and interleukin-4 triggers and supports their proliferation synergistically with interleukin-3
Authors: Tsuji K , Nakahata T , Takagi M , Kobayashi T , Ishiguro A , Kikuchi T , Naganuma K , Koike K , Miyajima A , Arai K 
Published: October 2019

Abstract
We examined the effects of interleukin-3 (IL-3) and interleukin-4 (IL- 4) on connective tissue-type mast cells (CTMC) purified from murine peritoneal cells. Although both factors failed to induce extensive proliferation of CTMC, they stimulated CTMC proliferation synergistically in a dose-dependent manner. Pretreatment of CTMC with IL-3 and/or IL-4 indicated that the sustained presence of both factors was required for the development of type 1 mast cell colonies. The delayed addition of IL-3 to cultures of purified CTMC with IL-4 induced no colony formation, while the delayed addition of IL-4 to cultures with IL-3, even on day 28 of culture, induced type 1 colony formation. In replating type 1 colonies induced by IL-3 and IL-4 to secondary cultures with IL-3 alone, few secondary colonies developed. However, the delayed addition of IL-4 to the secondary culture induced many type 1 colonies. The purified CTMC cultured with IL-3 retained the morphological and cytochemical characteristics of CTMC, as well as proliferative ability. These observations indicate that IL-3 supports the survival of CTMC in methylcellulose culture and that IL-4 triggers and supports CTMC proliferation synergistically with IL-3. The serum- free culture of purified CTMC and the culture of single CTMC demonstrated that the synergistic effect of IL-3 and IL-4 on colony growth and the surviving effect of IL-3 on CTMC require no influence from accessory cells or other humoral factors.
Human neutrophils contain a protein kinase C-like enzyme that utilizes guanosine triphosphate as a phosphate donor. Cofactor requirements, kinetics, and endogenous acceptor proteins
Authors: Stoehr SJ , Smolen JE 
Published: October 2019

Abstract
Investigations of protein kinase C (PKC) activity have focussed on protein phosphorylation using adenosine triphosphate (ATP), not guanosine triphosphate (GTP), as the phosphate donor. In a continuing study of the enzymology of the PKC of human neutrophils, we wanted to determine if there might be protein kinases that do use GTP as a phosphate donor. Soluble extracts or detergent-extracted fractions of human neutrophils were used as enzyme sources. Phosphorylation of histone using [gamma-32P]-GTP was 31% as effective as [gamma-32P]-ATP. Phosphorylation with GTP depended on Ca2+, Mg2+, and phospholipid, just as the ATP, and the Ca2+ requirements were similar. In all cases, H-7, an inhibitor of ATP-supported PKC activity, blocked GTP-utilizing activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that similar endogenous proteins were phosphorylated with ATP or GTP. The apparent Km and Vmax for the enzyme(s) for both phosphate donors were identical, although these were modified by treatment with Triton X-100. GTP competitively inhibited use of ATP by PKC; however, low concentrations of ATP enhanced GTP- utilizing kinase activity in some cases. Non-hydrolyzable forms of ATP and other nucleotide triphosphates were inhibitory. Detergent treatment also markedly altered the number of proteins phosphorylated by either nucleotide. The major protein phosphorylated in the soluble or detergent extract was a single polypeptide band in the 34 Kd range. These studies are the first to explicitly examine the possible phosphorylation by neutrophil PKC using GTP and point to a potential alternative mode of enzyme activity. Since high concentrations of GTP are available within neutrophils, the ability of PKC or a PKC-like enzyme to use this nucleotide may have important ramifications in signal transduction.
Sequence analysis of the gamma-globin gene locus from a patient with the deletion form of hereditary persistence of fetal hemoglobin
Authors: Stolle CA , Penny LA , Ivory S , Forget BG , Benz EJ Jr 
Published: October 2019

Abstract
The gamma-globin genes from a patient homozygous for a deletion form of hereditary persistence of fetal hemoglobin (HPFH-1) have been cloned and sequenced. The DNA sequence of the patient's gamma-globin genes corresponds to a previously identified sequence framework (chromosome A) with the exception of 10 base changes. Seven of these base changes can be attributed to normal allelic variation generated by small gene conversion events. The remaining three base changes are present in a 0.76 kb HindIII fragment containing a putative enhancer located 3′ to the A gamma-globin gene. The same three base changes have also been described in the Seattle variant of nondeletion HPFH. We have analyzed 16 alleles from non-HPFH individuals and five alleles from individuals with nondeletion or deletion HPFH for the presence of these base changes by polymerase chain reaction amplification of cloned or chromosomal DNA and hybridization to allele-specific oligonucleotide probes. Although these base changes were found in an individual with HPFH-2, they were not found in the DNA from two patients with nondeletion HPFH. More importantly, all three base changes were detected in DNA from five non-HPFH individuals and appear to be common in blacks. We conclude that these base changes do not correlate with an HPFH phenotype and that the significant mutation in HPFH-1 is the deletion of over 100 kb of genomic DNA.
Effects of tiazofurin on guanine nucleotide binding regulatory proteins in HL-60 cells
Authors: Kharbanda SM , Sherman ML , Kufe DW 
Published: October 2019

Abstract
Guanine nucleotide binding proteins (G proteins) are regulatory molecules that couple membrane receptors to effector systems such as adenylate cyclase and phospholipase C. The alpha subunits of G proteins bind to guanosine 5′-diphosphate (GDP) in the unstimulated state and guanosine 5′ triphosphate (GTP) in the active state. Tiazofurin (2-beta- D-ribofuranosylthiazole-4-carboxamide), a specific inhibitor of inosine monophosphate (IMP) dehydrogenase, decreases guanylate synthesis from IMP in HL-60 promyelocytic leukemia cells and depletes intracellular guanine nucleotide pools. This study demonstrates that treatment of HL- 60 cells with tiazofurin is associated with a fourfold increase in membrane binding sites for the nonhydrolyzable analogue GDP beta S. This increase in binding sites was associated with a 3.2-fold decrease in GDP beta S binding affinity. Similar findings were obtained with GTP gamma S. These effects of tiazofurin treatment on guanine nucleotide binding were also associated with decreased adenosine diphosphate- ribosylation of specific G protein substrates by cholera and pertussis toxin. The results further demonstrate that tiazofurin treatment results in inhibition of G protein-mediated transmembrane signaling mechanisms. In this regard, stimulation of adenylate cyclase by prostaglandin E2 was inhibited by over 50% in tiazofurin-treated cells. Furthermore, tiazofurin treatment resulted in inhibition of N- formylmethionylleucylphenylalanine-induced stimulation of phospholipase C. Taken together, these results indicate that tiazofurin acts at least in part by inhibiting the ability of G proteins to function as transducers of intracellular signals.