bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential regulation by cytokines of constitutive and stimulated secretion of von Willebrand factor from endothelial cells
Authors: Paleolog EM , Crossman DC , McVey JH , Pearson JD 
Published: October 2019

Abstract
We examined the effect of cytokines on basal and agonist-stimulated release of von Willebrand factor (vWf) by human endothelial cells. Treatment of endothelial cells for up to 48 hours with human recombinant or purified interleukin 1 (IL-1) or human recombinant tumor necrosis factor-alpha (TNF-alpha) did not significantly affect constitutive secretion of vWf or intracellular levels of vWf, although basal prostacyclin (PGI2) production was markedly enhanced. In contrast, both IL-1 and TNF-alpha modulated vWf release in response to thrombin or phorbol ester. Pretreatment of endothelial cells for 2 hours with either cytokine enhanced by up to threefold the stimulatory effect of a subsequent 60-minute exposure to thrombin. Addition of cycloheximide (5 micrograms/mL) during the preincubation abolished this enhancement. Moreover, if the cytokine pretreatment time was extended to 24 hours, agonist-stimulated vWf release was significantly suppressed. Cytokine treatment for 2 or 24 hours had no detectable effect on levels of vWf messenger RNA. The effects of cytokines were not the result of contamination with bacterial lipopolysaccharide and were not attributable to endothelial cell injury. These results show that cytokines have little or no direct effect on vWf release from endothelial cells but can significantly modulate its acute release in response to other stimuli in a complex time- and dose-dependent manner.
Effect of tamoxifen on regulation of viral replication and human immunodeficiency virus (HIV) long terminal repeat-directed transcription in cells chronically infected with HIV-1
Authors: Laurence J , Cooke H , Sikder SK 
Published: October 2019

Abstract
The protein kinase C (PKC) activator phorbol myristate acetate (PMA) was used to upregulate viral replication in a clone of promonocytic cells chronically infected with human immunodeficiency virus (HIV)-1. Induction of virus could be inhibited by the triphenylethylene anti- estrogen tamoxifen at concentrations that had minimal effects on cellular DNA synthetic responses and cell cycle kinetics. This effect correlated with tamoxifen's ability to block PMA-mediated enhancement of HIV-promoter-driven transactivation in cells of monocyte and CD4+ T- lymphocyte lineages. No interference with a primary infection was noted. Tamoxifen's mechanism of action may relate both to its capacity to inhibit PKC and to consensus sequences for gonadal steroid responsive elements in the HIV long terminal repeat, as it was able to partially inhibit another HIV activator, 5-azacytidine, which does not modulate PKC function. The finding that regulation of HIV in a model for low-level chronic or latent infection is amenable to a nonimmunosuppressive steroid antagonist may suggest approaches to pharmacologic intervention early in HIV infection.
Homozygous deletion of the retinoblastoma gene in an acute lymphoblastic leukemia (T) cell line
Authors: Cheng J , Scully P , Shew JY , Lee WH , Vila V , Haas M 
Published: October 2019

Abstract
Human leukemia cell lines were examined for the status of the retinoblastoma (RB) protein by immunoblotting analysis using antibodies raised against the TrpE-RB fusion protein. One of 16 cell lines examined, the T-cell acute lymphoblastic leukemia (ALL) line HSB-2, lacked the 110-Kd RB protein. Southern blot analysis of genomic DNA extracted from HSB-2 cells showed a large homozygous deletion of the RB gene, stretching from exon 18 beyond exon 27. Northern blot analysis showed multiple, abnormal RB transcripts in HSB-2. A truncated protein (72 Kd) was detected with 35S-methionine labeling but not with 32P- orthophosphate labeling of the HSB-2 cells. The genomic deletion of greater than 85 kb DNA at the RB locus (13q14) was not detectable in the karyotype of the HSB-2 cells. Among the 16 human leukemia cell lines examined for the status of the RB gene, only one, the HSB-2 line, showed an abnormal RB protein. Further study of primary leukemia and lymphoma samples appears to be warranted.
A fixed low number of T cells in HLA-identical allogeneic bone marrow transplantation
Authors: Verdonck LF , de Gast GC , van Heugten HG , Dekker AW 
Published: October 2019

Abstract
Allogeneic bone marrow transplantation (BMT) in humans is hampered mainly by graft-versus-host disease (GVHD). Ex vivo T-cell depletion of the marrow graft has decreased the incidence and severity of GVHD, but has resulted in a higher incidence of graft failure and of relapse of the disease. In order to find an optimal T-cell number that avoids the extreme risks on both sides, we performed BMTs with a fixed low number of T cells. Thirty-one patients received marrow grafts, containing 1 x 10(5) T cells per kilogram body weight, from their HLA-identical sibs. All patients, except one, received cyclosporin A. Engraftment of donor marrow cells occurred in all patients and (late) graft rejections are not observed to date. Eighteen of 30 (60%) evaluable patients had acute GVHD, grade I (10 patients) or grade II (8 patients), limited to the skin in all patients. Chronic GVHD, also limited to the skin, was found in 9 of 27 (33%) evaluable patients. Incidence but not severity of GVHD in our study seems similar to that observed in non-T-cell depleted marrow grafting. Relapse was observed in 1 of 13 leukemic patients transplanted in first (or second) remission or first chronic phase with a follow-up of at least 6 months. These results suggest that with a fixed low number of T cells severe GVHD and failure to engraft can be avoided. More patients and longer follow-up are necessary for conclusions regarding relapse rate and late graft failure.
Heterogeneity in the properties of burst-forming units of erythroid lineage in sickle cell anemia: DNA synthesis and burst-promoting activity production is related to peripheral hemoglobin F levels
Authors: Croizat H , Billett HH , Nagel RL 
Published: October 2019

Abstract
Circulating 14-day erythroid progenitors (BFU-E) from 28 sickle cell anemia (SS) patients with hemoglobin F (HbF) levels ranging from 2% to 16% were studied to determine their sensitivity to [3H] thymidine kill and burst-promoting activity (BPA)-like factor production. We find that the proportion of BFU-E sensitive to 3H-dT kill, and hence active in DNA synthesis, was inversely correlated with the percent of peripheral HbF when light density (LD) mononuclear cells were used for plating. Regression analysis showed that the correlation between HbF level and BFU-E kill was highly significant (r = .88; P less than .00003). We confirmed the BPA-like factor(s) production by LD mononuclear cells of SS patients, and found, in addition, that this phenomenon is restricted to the population of SS patients with HbF levels lower than 9%. Circulating BFU-E of patients with high HbF levels are not sensitive to 3H-dT, and their mononuclear cells do not release BPA-like factor. In summary, SS patients exhibit differences in the capacity of their mononuclear cells to produce BPA activity according to their peripheral HbF level, as well as to the DNA synthesis-state of their circulating BFU-E. We conclude that erythroid progenitors differ among SS patients in relation to their peripheral HbF level.
Treatment of corticosteroid resistant acute graft-versus-host disease by in vivo administration of anti-interleukin-2 receptor monoclonal antibody (B-B10) [see comments]
Authors: Herve P , Wijdenes J , Bergerat JP , Bordigoni P , Milpied N , Cahn JY , Clement C , Beliard R , Morel-Fourrier B , Racadot E 
Published: October 2019

Abstract
In a multicenter pilot study, 32 patients showing steroid-resistant acute graft-versus-host disease (GVHD) were treated by in vivo administration of anti-interleukin-2 (IL-2) receptor monoclonal antibody (MoAb B-B10). Twenty-three patients received marrow from HLA- matched related donors, four from matched unrelated donors and five from partially matched related donors. The overall grade of GVHD was II in 16 patients, III in two, and IV in five. Five milligrams of B-B10 MoAb was infused in bolus daily for 10 days and then every second day for a further 10 days in an attempt to reduce GVHD recurrence. No clinical side effects were noted during the B-B10 treatment period. A complete response (CR) acute GVHD was achieved in 21 patients (65.6%). Six patients (18.7%) showed partial improvement (PR) and 5 patients (15.6%) no response (NR). A significant factor associated with GVHD response was the delay between the onset of the GVHD and the first day of B-B10 infusion. The earlier B-B10 was introduced, the greater the probability of CR (P = .03). There was no correlation between the serum B-B10 level and GVHD response (P = .69). There was, however, a significant correlation between the clinical response and the B-B10 kinetics as a function of time: serum B-B10 levels attained a plateau level more rapidly in the CR group than in the PR/NR group. Among the 26 complete and partial evaluable responders, GVHD recurred in 10 cases (38.4%). Host anti-B-B10 MoAb immune response occurred in only one (7.1%) of the 14 patients analyzed. Fourteen of the 32 patients (43.7%) are currently alive between 2 and 14 months after GVHD treatment with B- B10 was completed.
Prognostic value of pretreatment serum beta 2 microglobulin in myeloma: a Southwest Oncology Group Study [see comments]
Authors: Durie BG , Stock-Novack D , Salmon SE , Finley P , Beckord J , Crowley J , Coltman CA 
Published: October 2019

Abstract
Six hundred twelve eligible, previously untreated patients with active multiple myeloma and at least some data available for analysis were entered into a randomized trial (Southwest Oncology Group [SWOG] Phase III myeloma study 8229/30), in which the prognostic significance of pretreatment serum beta 2 microglobulin levels was evaluated. Because there was no statistically significant survival difference between the alternating and syncopating VMCP/VBAP regimens, it was possible to evaluate serum beta 2 microglobulin for the total population all together. The serum beta 2 microglobulin measurements showed the highest significance of any prognostic factor, both in the bivariate and multivariate regression analyses. The median survival was 36 months for the 322 patients with pretreatment serum beta 2 microglobulin values of less than 6 micrograms/mL, as compared with a median survival of 23 months for the 225 patients with a beta 2 level of greater than or equal to 6 mcg/mL (P less than .0001). The stepwise multiple regression model first contained serum beta 2 microglobulin, followed by serum albumin, serum calcium, age, and serum creatinine. Serum beta 2 microglobulin was highly correlated with stage: median values ranged from 3.7 micrograms/mL for stage IA, to 10.1 for stage IIIB. It was possible to stratify myeloma patients based on combinations of serum beta 2 microglobulin with both albumin and age, producing excellent separation of patients into low-, intermediate-, and high-risk categories. It is concluded that serum beta 2 microglobulin is the most powerful prognostic factor currently available for multiple myeloma and that it can be used alone or in combination with other variables for pretreatment stratification.
Inhibition of receptor binding and neutralization of bioactivity by anti-erythropoietin monoclonal antibodies
Authors: D'Andrea AD , Szklut PJ , Lodish HF , Alderman EM 
Published: October 2019

Abstract
We have generated four high affinity monoclonal antibodies (MoAbs) to recombinant human erythropoietin (EPO). All four MoAbs immunoprecipitate radioiodinated native EPO, and the concentrations of MoAbs required for maximum binding range from 10 nmol/L to 100 nmol/L. Two MoAbs, designated Group I MoAbs, bind to an epitope within the N- terminal 20 amino acids of EPO and also immunoprecipitate sodium dodecyl sulfate (SDS)-denatured EPO. Two other MoAbs (Group II MoAbs) do not immunoprecipitate SDS-denatured EPO and do not bind to any of the eight endo C fragments of EPO. We first used murine erythroleukemia (MEL) cells to test the MoAbs for inhibition of EPO-receptor binding. MEL cells, although unresponsive to EPO, express 760 high affinity receptors for EPO per cell (Kd = 0.24 nmol/L). To assay our MoAbs, MEL cells were grown as monolayers on fibronectin-coated Petri dishes and incubated at 4 degrees C with radioiodinated EPO. Group I MoAbs do not inhibit binding of radioiodinated EPO to the MEL EPO-receptor, but Group II MoAbs do inhibit binding in a dose-dependent manner. We next examined the neutralization of EPO bioactivity by our MoAbs, using EPO- dependent cell line. Only Group II MoAbs inhibit a newly developed EPO- dependent cell growth, demonstrating that inhibition of EPO-receptor binding correlates with neutralization of EPO bioactivity.
Homocysteine, an atherogenic stimulus, reduces protein C activation by arterial and venous endothelial cells
Authors: Rodgers GM , Conn MT 
Published: October 2019

Abstract
Elevated blood levels of homocysteine are associated with atherosclerosis and thrombotic disease. We previously reported that treatment of cultured endothelial cells with homocysteine increased endogenous factor V activity by activation of the cofactor. Because endothelial cell-associated factor Va would be regulated by the protein C mechanism, the ability of homocysteine-treated arterial and venous endothelial cells to activate protein C was investigated. Both arterial and venous endothelial cells activated protein C; 0.6 mmol/L homocysteine reduced endothelial cell protein C activation by 12%. Maximal inhibition (90%) of protein C activation occurred with 7.5 to 10 mmol/L homocysteine after 6 to 9 hours of incubation. Metabolism of homocysteine was not accelerated by cultured endothelial cells. Investigation of the mechanism(s) by which homocysteine reduced protein C activation indicated that the metabolite did not induce an inhibitor to activated protein C, but in low concentrations acted as a competitive inhibitor to thrombin. These data suggest that perturbation of the vascular endothelial cell protein C mechanism by homocysteine may contribute to the thrombotic tendency seen in patients with elevated blood levels of this metabolite.
Platelet factor 4 and the platelet secreted proteoglycan: immunologic characterization by crossed immunoelectrophoresis
Authors: Levine SP , Knieriem LK , Rager MA 
Published: October 2019

Abstract
Platelet factor 4 (PF4) is a hydrophobic, alpha-granule protein with potent antiheparin activity. It also binds to a chondroitin sulfate- containing proteoglycan (PG) isolated from platelets. In order to evaluate further the relationship between PF4 and the chondroitin sulfate-containing proteoglycan in resting platelets, the PF4-binding proteoglycan from human platelets has been purified using purified PF4 as an affinity ligand and used to prepare polyclonal antiserum. Two antisera have been characterized: one reacts primarily with chondroitin sulfate (CS), the other reacts with the protein core of the platelet proteoglycan after chondroitinase AC digestion. PF4 and PG core protein antigen are present in separate, dissimilar precipitin arcs when triton- solubilized platelets are analyzed by crossed immunoelectrophoresis using polyclonal antisera to purified PF4 and PG. PF4 was demonstrated in a complex with a separate chondroitin sulfate antigen by crossed immunoelectrophoresis (CIE) experiments in which either anti-PF4 or anti-CS antisera was incorporated in the intermediate gel. Both the PF4- chondroitin sulfate complex and the proteoglycan are secreted from platelets when fresh, washed human platelets are stimulated by human alpha-thrombin. This second antigen may represent the PG after posttranslational modification of a precursor form of the proteoglycan.
Tumor necrosis factor/cachectin and lymphotoxin gene expression in lymph nodes from lymphoma patients
Authors: Sappino AP , Seelentag W , Pelte MF , Alberto P , Vassalli P 
Published: October 2019

Abstract
We investigated the mRNA content for tumor necrosis factor (TNF)/cachectin and lymphotoxin (LT) in tumoral tissues of a prospective series of 35 non-Hodgkin's (NHL) and 23 Hodgkin's (HL) lymphomas, to assess their postulated contribution to systemic symptoms. Total RNAs were extracted from diagnostic tissue specimens and submitted to Northern blot analysis, using specific TNF and LT cRNA probes. High amounts of TNF mRNA were found exclusively in NHL (12/35). The majority (9/12) of these were low grade B-cell NHL, which contained a uniform population of malignant cells. In contrast, abundant LT mRNA production was detected in most HL (21/23) and in 19 of 35 NHL. The highest LT mRNA levels were observed in high grade NHL and in lymphocytic predominant subtypes of HL specimens. A significant correlation was found between TNF/cachectin and LT gene expression in NHL and the presence of constitutional symptoms. The biologic and prognostic implications of these preliminary findings are presently unknown, but they demonstrate that lymphoma tissues sharing common histologic features are highly heterogeneous in their ability to synthesize cytokines susceptible to playing a role in the growth control of malignant cells. These results suggest that the evaluation of TNF/cachectin and LT production in lymphomas may help to elucidate the mechanisms of tumoral fever and cachexia.
Isolation of an early T-cell precursor (CFU-TL) from human bone marrow
Authors: Bertho JM , Mossalayi MD , Dalloul AH , Mouterde G , Debre P 
Published: October 2019

Abstract
CD2-CD3-CD4-CD8- human bone marrow (BM) cells were previously shown to generate T-cell clones in vitro. This capacity was abolished after treatment of this population with anti-CD7 monoclonal antibody and complement. In this study, using rosetting with sheep erythrocytes, complement-dependent cytotoxicity, and specific immunoadherence method, we isolated a minor BM subset that contained more than 80% CD7+CD2-CD3- CD4-CD8- cells with small lymphoid cell morphology. They comprised most early T-cell precursors (CFU-TL) as they displayed high capacity to generate T-cell clones when cultured in limiting dilutions. CFU-TL nature of these cells was also confirmed by the sequential expression of mature T-cell specific markers on their surface after in vitro induction. This BM subset also contained 2% to 3% CFU-GM precursors. Together, these results pointed to the existence of BM CD7+CD2- precursors with high differentiation potential and showed the commitment of most of them to T-cell lineage.
Factor VIIa-catalyzed activation of factor X independent of tissue factor: its possible significance for control of hemophilic bleeding by infused factor VIIa
Authors: Rao LV , Rapaport SI 
Published: October 2019

Abstract
Infusing factor VIIa (FVIIa) has been reported to control bleeding in hemophilic patients with factor VIII (FVIII) inhibitors. This is difficult to attribute to an enhanced FVIIa/tissue factor (TF) activation of factor X, since in vitro studies suggest that infusion of FVIIa should neither increase substantially the rate of formation of FVIIa/TF complexes during hemostasis (Proc Natl Acad Sci USA 85:6687, 1988) nor bypass the dampening of TF-dependent coagulation by the extrinsic pathway inhibitor (EPI) (Blood 73:359, 1989). Partial thromboplastin times have also been reported to shorten after infusion of FVIIa. The experiments reported herein establish that shortening of partial thromboplastin times after adding FVIIa to hemophilic plasma in vitro stems from an FVIIa-catalyzed activation of factor X independent of possible trace contamination of reagents with TF. Experiments in purified systems confirmed that FVIIa can slowly activate factor X in a reaction mixture containing Ca2+ and phospholipid but no source of TF. The rate of activation was sufficient to account for the shortening of partial thromboplastin times observed. EPI, which turned off continuing FVIIa/TF activation of factor X, was unable to prevent continuing FVIIa/phospholipid activation of factor X. Because circulating plasma contains only a trace, if any, free FVIIa, such a reaction could never occur physiologically. However, infusing FVIIa creates a nonphysiologic circumstance in which a continuing slow FVIIa/phospholipid catalyzed activation of factor X could conceivably proceed in vivo unimpeded by EPI. Such a mechanism of factor X activation might compensate for an impaired factor IXa/FVIIIa/phospholipid activation of factor X during hemostatis, and therefore control bleeding in a hemophilic patient.
Factor IX New London: substitution of proline for glutamine at position 50 causes severe hemophilia B
Authors: Lozier JN , Monroe DM , Stanfield-Oakley S , Lin SW , Smith KJ , Roberts HR , High KA 
Published: October 2019

Abstract
We describe a novel point mutation in the fourth exon of human factor IX (encoding the first EGF-like domain) in which cytosine is substituted for adenosine at position 10,401, resulting in the substitution of proline for glutamine at position 50 in the polypeptide chain. Sequence analysis of all eight exons, all exon-intron junctions, 160 base pairs (bp) of DNA 5′ to the proposed translation start site, and 60 bp 3′ to the translation termination site shows no other difference from the normal factor IX gene, with the exception of a previously described benign polymorphism at position 148 in the protein (Ala----Thr). The affected subject has severe hemophilia B with no detectable factor IX activity despite normal factor IX antigen levels. We purified the abnormal factor IX by immunoaffinity chromatography and demonstrated that its activation by factor Xla is markedly delayed compared with normal factor lX. Once activated, the abnormal factor lX binds antithrombin III in a 1:1 molar ratio, and the activated protein demonstrates catalytic activity, suggesting an intact active site. The mutation creates a new Bst Yl restriction endonuclease cleavage site. Restriction with Bst Yl shows the mutation in maternal DNA and offers the possibility of direct carrier status analysis and prenatal diagnosis in kindreds with this mutation. We designate this new mutation factor lXNew London. This is the only reported mutation in the first EGF-like domain that causes severe hemophilia B.
Chronic myeloid leukemia may be associated with several bcr-abl transcripts including the acute lymphoid leukemia-type 7 kb transcript [see comments]
Authors: Selleri L , von Lindern M , Hermans A , Meijer D , Torelli G , Grosveld G 
Published: October 2019

Abstract
In the majority of Philadelphia (Ph)-positive chronic myeloid leukemia (CML) patients, the c-abl gene is fused to the bcr gene, resulting in the transcription of an 8.5 kb chimeric bcr-abl mRNA, which is translated into a p210bcr-abl fusion protein. In about 50% of the Ph- positive acute lymphoid leukemias (ALL), the bcr-abl gene fusion is identical to CML, while in 50% an alternative fusion between these two genes occurs, in which the central bcr-sequences are absent. This results in transcription of a 7 kb bcr-abl mRNA, encoding a P190bcr-abl fusion protein. Cloning and sequencing of the chimeric part of bcr-abl cDNAs from two Ph-positive CML patients in chronic phase showed that in one patient, as in the Ph-positive ALL, all central bcr sequences are absent, while in the other patient, part of the bcr central sequences are deleted. Therefore, we speculate that the presence of the 7 kb chimeric ALL type mRNA in one of the patients is not sufficient to drive an acute rather than a chronic leukemic process in this case. The deletions of the central bcr-sequences described here define the minimal sequence requirement of the bcr-abl fusion gene in CML patients so far.