bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of delta-globin gene mutations in Greek cypriots
Authors: Trifillis P , Kyrri A , Kalogirou E , Kokkofitou A , Ioannou P , Schwartz E , Surrey S 
Published: October 2019

Abstract
We recently described four delta-globin gene mutations in Greek Cypriots studied by polymerase chain reaction (PCR) amplification and automated fluorescence-based DNA sequence analysis (Blood 78:3298, 1991). Selective restriction enzyme digestion of PCR products facilitated direct mutation detection. Twenty-eight additional samples from unrelated Cypriots with Hb A2 levels ranging from 0.6% to 3.6% were studied by PCR and showed the following: twelve had the delta 27 (ala-->ser) mutation, one was heterozygous for the delta IVS-2 AG-->GG change, and none had either the delta 116 (arg-->cys) or delta 141 (leu- ->pro) mutations. The remaining samples were divided into two groups: 11 with borderline normal Hb A2 values that were not pursued; and four with abnormal Hb A2 values. The delta-globin genes from these four samples were sequenced and the same four changes identified in each: a C-->T at -199, a C-->T at codon 4 (thr-->ile), a silent C-->T at codon 97, and an AT deletion at position 722 in IVS-2. The codon 4 change abolishes a Ple I site whereas the codon 97 creates an Nla III site, thus facilitating rapid identification. All four changes are in cis position, suggesting that the -199 C-->T, the C-->T at codon 97, and the AT deletion in IVS-2 are neutral polymorphisms present on the codon 4 (thr-->ile) chromosome. DNA haplotype analysis suggests all five delta-globin gene mutant alleles arose independently on different chromosomal backgrounds.
Alpha 4 beta 1-integrin expression on sickle reticulocytes: vascular cell adhesion molecule-1-dependent binding to endothelium
Authors: Swerlick RA , Eckman JR , Kumar A , Jeitler M , Wick TM 
Published: October 2019

Abstract
Important complications in sickle cell anemia occur secondary to vascular occlusion, which is postulated to be initiated by interactions of erythrocytes with vascular endothelial cells. In patients with sickle cell anemia, up to 25% of reticulocytes express the alpha 4 beta 1-integrin complex. Furthermore, erythrocytes from patients with sickle cell anemia bind to endothelial cells activated by tumor necrosis factor alpha via (TNF alpha) via interactions between erythrocyte alpha 4 beta 1 and endothelial cell vascular cell adhesion molecule-1 (VCAM- 1). Thus, binding of alpha 4 beta 1-expressing reticulocytes to cytokine-activated endothelial cells may initiate vascular complications in sickle cell anemia and perhaps other hemolytic anemias during episodes of infection and inflammation.
Cytokines in inflammatory malignant fibrous histiocytoma presenting with leukemoid reaction
Authors: Melhem MF , Meisler AI , Saito R , Finley GG , Hockman HR , Koski RA 
Published: October 2019

Abstract
Inflammatory malignant fibrous histiocytomas (IMFH) are rare tumors and are frequently associated with leukocytosis. In rare cases, leukemoid reactions were attributed to tumor production of unidentified hematopoietic factors. In this study, we used immunohistochemical techniques to show cytokine immunoreactivity in the malignant cells of two cases of IMFH presenting with leukemoid reactions and compared them with two malignant fibrous histocytomas, noninflammatory type. All four tumors stained positively for stem cell factor (SCF), granulocyte colony-stimulating factor (G-CSF), interleukin-2 (IL-2), IL-4, IL-5, interferon-alpha (IFN-alpha), and insulin-like growth factor-I. Other cytokines detected only in the two IMFH included IL-6, IL-7, IL-8, IFN- gamma, and keratinocyte growth factor. Granulocyte-macrophage-CSF, IL- 3, and transforming growth factor-beta staining was present in one of the two IMFH tumors and was not present in the noninflammatory tumors. The immunohistochemical staining was localized to the malignant cells, suggesting deregulated cytokine expression consistent with their monocytic/histocytic origin. Expression of certain cytokines in the IMFH may account for the local inflammatory infiltrate, tumor fibrosis, and the aggressive nature of the malignant cells. We also detected elevated serum levels of SCF, G-CSF, IL-6, and tumor necrosis factor in one or both of the IMFH patients. These latter observations may explain the bone marrow hypercellularity and other paraneoplastic symptoms, including fever, malaise, and weight loss, observed in both patients. Different cytokines present in the two IMFH tumors appear to be responsible for the eosinophilic leukemoid reaction observed in one case and for the granulocytic leukemoid reaction observed in the other patient. They may also be responsible for expansion of the tumor-cell population, fibroblast proliferation, and enhanced secretion of extracellular collagen.
Phenotypic and clonal analysis of T lymphocytes in childhood immune thrombocytopenic purpura
Authors: Ware RE , Howard TA 
Published: October 2019

Abstract
In an attempt to identify and characterize T-lymphocyte immunoregulatory abnormalities in immune thrombocytopenic purpura (ITP), we have performed phenotypic and clonal analysis on peripheral T lymphocytes from 23 children with ITP. Quantitation of lymphocyte subpopulations showed that children with acute ITP had higher numbers of CD45RA+ and lower numbers of CD45RO+ T cells than children with chronic ITP or controls, but these differences may be age related. Analysis of T-cell receptor variable beta gene usage identified 2 boys with chronic ITP and elevated numbers of V beta 8+ T cells. Eight T- cell clones were established (6 CD4+, 4B4+ helper-inducer lines and 2 CD8+ lines) that showed in vitro proliferation against allogeneic platelets. The addition of autologous antigen-presenting cells enhanced the proliferation of six clones, but not for two clones that coexpressed natural killer (NK) markers. Four of seven positive clones also had measurable interleukin (IL)-2 secretion following platelet stimulation, providing further evidence for T-cell reactivity. Our results provide the first evidence that patients with ITP may have platelet-reactive T lymphocytes identifiable at the clonal level, supporting the hypothesis that autoreactive peripheral T lymphocytes may mediate or participate in the pathogenesis of this disorder.
X-linked chronic granulomatous disease: correction of NADPH oxidase defect by retrovirus-mediated expression of gp91-phox
Authors: Porter CD , Parkar MH , Levinsky RJ , Collins MK , Kinnon C 
Published: October 2019

Abstract
Chronic granulomatous disease (CGD) is an inherited immunodeficiency resulting from the inability of an individual's phagocytes to produce superoxide anions because of defective NADPH oxidase. The disease may be treated by bone marrow transplantation and as such is a candidate for somatic gene therapy. Two thirds of patients have defects in an X- linked gene (X-CGD) encoding gp91-phox, the large subunit of the membrane cytochrome b-245 component of NADPH oxidase. Epstein-Barr virus-transformed B-cell lines from patients with CGD provide a model system for the disease. We have used retrovirus-mediated expression of gp91-phox to reconstitute functionally NADPH oxidase activity in B-cell lines from three unrelated patients with X-CGD. The protein is glycosylated and membrane associated, and the reconstituted oxidase is appropriately activated via protein kinase C. The kinetics of superoxide production by such reconstituted cells is similar to that of normal B-cell lines. These data show the potential of gene therapy for this disease.
p53 mutations are associated with histologic transformation of follicular lymphoma
Authors: Lo Coco F , Gaidano G , Louie DC , Offit K , Chaganti RS , Dalla-Favera R 
Published: October 2019

Abstract
The majority of low-grade non-Hodgkin's lymphomas (NHL) undergo clinical progression toward intermediate- and high-grade lymphomas. This progression is often associated with histologic transformation from follicular to diffuse-type NHL. The pathogenetic mechanisms underlying this evolution are presently unknown. In this study, we have analyzed the role in NHL progression of relevant genetic lesions affecting proto-oncogenes and tumor suppressor genes. Sequential biopsies from 21 patients with clinical progression with (5 cases) or without (16 cases) evidence of histologic transformation were analyzed for karyotypic changes, c-myc rearrangements and deletions affecting 6q27 by Southern blot analysis, and p53 mutations by single-strand conformation polymorphism (SSCP) analysis coupled with direct sequencing of polymerase chain reaction-amplified products. No novel cytogenetic aberration was detected in association with progression, and all samples analyzed displayed a normal c-myc gene. Mutations of the p53 gene were detected in 4 of 5 cases displaying histologic transformation from follicular to diffuse-type NHL and in none of the 16 cases displaying clinical progression in the absence of histologic transformation. In 1 of these positive cases, the same mutation was also present in the pretransformation biopsy, correlating with the presence of diffuse-type areas within a predominant follicular pattern. In 1 of these cases, a deletion of 6q27 was also detected in the posttransformation biopsy along with a p53 mutation. These findings indicate that p53 mutations are associated with and may be responsible for histologic transformation of follicular lymphoma.
Interleukin-10 inhibits the osteogenic activity of mouse bone marrow
Authors: Van Vlasselaer P , Borremans B , Van Den Heuvel R , Van Gorp U , de Waal Malefyt R 
Published: October 2019

Abstract
Murine bone marrow cells synthesize bone proteins, including alkaline phosphatase (ALP), collagen type I, and osteocalcin, and form a mineralized extracellular matrix when cultured in the presence of beta- glycerophosphate and vitamin C. Interleukin-10 (IL-10) suppressed the synthesis of these bone proteins and mineralization without affecting cell proliferation. In addition, mRNA levels for the latter proteins were reduced in IL-10-treated cultures. This inhibitory effect was most outspoken when IL-10 was added before ALP activity peaked, eg, day 15 of culture. No significant effect was observed when IL-10 was added at later time points. This finding suggests that IL-10 acts at osteogenic differentiation stages that precede ALP expression but is ineffective on cells that progressed beyond this maturation stage. Likewise, IL-10 appeared to be unable to block both ALP activity and collagen synthesis in the preosteosteoblastic cell lines MN7 and MC3T3 that constitutively synthesize these proteins. Whereas IL-10 did not alter the number of fibroblast colony-forming cells of the marrow, it significantly reduced their osteogenic differentiation potential. In contrast to control cultures, IL-10-treated stroma was unable to either synthesize osteocalcin or to mineralize when subcultured over a 25-day period in the absence of IL-10. The inhibitory activity of IL-10 coincided with significant changes in stroma morphology. Whereas control cultures contained mainly flat adherent polygonal cells, significant numbers of rounded semiadherent to nonadherent cells were observed in the presence of IL-10. Scanning and transmission electron microscopy showed that, in contrast to control cultures, IL-10-treated stromas completely lacked a mineralized extracellular matrix. Collectively, these data suggest that IL-10 may have important regulatory effects on bone biology because of its capacity to downregulate early steps of osteogenic differentiation.
Type-I interferons are potent inhibitors of interleukin-8 production in hematopoietic and bone marrow stromal cells
Authors: Aman MJ , Rudolf G , Goldschmitt J , Aulitzky WE , Lam C , Huber C , Peschel C 
Published: October 2019

Abstract
nterleukin-8 (IL-8) is produced by many cell types upon stimulation with bacterial products or inflammation-associated cytokines such as tumor necrosis factor-alpha and IL-1. Interferons (IFNs) represent another group of cytokines that are induced by similar stimuli in inflammatory reactions. We show now that type-I IFNs are potent inhibitors of IL-8 expression in vitro and in vivo. A significant reduction of both secretion of IL-8 protein and accumulation of IL-8 mRNA in vitro was observed in several cell types comprising peripheral blood mononuclear cells (PBMNC) from healthy donors and from patients with chronic myelogenous leukemia (CML), the myelomonocytic cell line THP-1, and bone marrow (BM) stromal cells as a representative model for BM microenvironment. By contrast, in lipopolysaccharide-stimulated polymorphonuclear phagocytes IFN failed to suppress IL-8 expression. In untreated patients with CML, a constitutive expression of IL-8 mRNA was detected in freshly isolated PBMNC that was markedly reduced 5 hours after therapeutic application of IFN-alpha. The mechanism of IL-8 downregulation was studied more in detail in the THP-1 cell line. The experiments showed that de novo protein synthesis was not required for the inhibitory effect. RNA decay analysis and nuclear run-on assays suggest that in THP-1 cell line the inhibition of IL-8 expression is predominantly regulated at the posttranscriptional level.
Splice site mutation in the human protein C gene associated with venous thrombosis: demonstration of exon skipping by ectopic transcript analysis
Authors: Lind B , van Solinge WW , Schwartz M , Thorsen S 
Published: October 2019

Abstract
Heterozygosity for a G-->C mutation converting the highly conserved Gln184 (CAG) to His (CAC) was identified at the last nucleotide of exon 7 of the protein C gene in two family members with deep vein thrombosis. As the nucleotide is a part of the 5 splice site of intron G, it was examined how the mutation affected splicing of protein C pre- mRNA. Relevant protein C cDNA fragments were amplified with polymerase chain reaction after reverse transcription of ectopic mRNA from peripheral blood lymphocytes. Southern blot analysis and nucleotide sequencing of these fragments showed a fragment (A) corresponding to correctly spliced mRNA originating from the normal allele and a fragment (B) corresponding to a truncated mRNA lacking exon 7, originating from the mutant allele. A third fragment (C) lacking exons 7 and 8 was identified in both affected and unaffected family members, as well as in normal controls. Analysis of human liver protein C mRNA indicated that the ectopic lymphocyte mRNA was qualitatively representative for the tissue-specific mRNA. In conclusion, evidence is provided showing that the mutation abolishes formation of correctly spliced mRNA. This agrees with the observation that the mutation results in a type 1 protein C deficiency.
Dusart syndrome: a new concept of the relationship between fibrin clot architecture and fibrin clot degradability: hypofibrinolysis related to an abnormal clot structure
Authors: Collet JP , Soria J , Mirshahi M , Hirsch M , Dagonnet FB , Caen J , Soria C 
Published: October 2019

Abstract
Fibrinogen Dusart is a congenital dysfibrinogenemia (A-alpha 554 Arginine-->Cysteine) associated with severe thrombotic disorder, high incidence of thrombotic embolism, and abnormal fibrin polymerization. This thrombotic disorder was attributed to an abnormal clot thrombolysis with reduced plasminogen binding to fibrin and defective plasminogen activation by tissue plasminogen activator. The purpose of this work was to assess whether clot architecture could be involved in the thromboresistance of the fibrin Dusart and the high incidence of embolism. An important change in Dusart fibrin clot structure was identified with dramatic decrease of gel porosity (Ks), fiber diameters (d), and fiber mass-length ratios (mu) derived from permeation analysis. In addition, rigidity of the Dusart clot was found to be greatly increased compared with normal fibrin. We provide evidence that both thrombolysis resistance and abnormal rigidity of the fibrin Dusart are related to this abnormal architecture, which impairs the access of fibrinolytic enzymes to the fibrin and which is responsible for a brittle clot that breaks easily, resulting in a high incidence of embolism. Indeed, when restoring a normal clot structure by adding dextran 40 (30 mg/mL) before coagulation, clot thrombolysis and clot rigidity recovered normal values. This effect was found to be dose- dependent. We conclude that clot architecture is crucial for the propensity of blood clot to be degraded and that abnormal clot structure can be highly thrombogenic in vivo. The alpha-C domains of fibrinogen are determinant in fibrin clot structure.
Production of granulocyte colony-stimulating factor in vitro by monocytes from preterm and term neonates [see comments]
Authors: Schibler KR , Liechty KW , White WL , Christensen RD 
Published: October 2019

Abstract
We postulated that defective generation of granulocyte colony- stimulating factor (G-CSF) by cells of newborn infants might underlie their deficiencies in upregulating neutrophil production and function during bacterial infection. To test this, we isolated monocytes from the blood of preterm neonates, term neonates, and adults and, after stimulation with various concentrations of interleukin-1 alpha (IL-1 alpha) or lipopolysaccharide (LPS), quantified G-CSF concentrations in cell supernatants and G-CSF mRNA in cell lysates. When stimulated with plateau concentrations of IL-1 alpha for 24 hours, G-CSF concentrations were higher in supernatants of adult cells (8,699 +/- 5,529 pg/10(6) monocytes) than in those from term infants (2,557 +/- 442 pg, P < .05) or from preterm infants (879 +/- 348 pg, P < .05 v adults). When stimulated with plateau concentrations of LPS, supernatants of monocytes from preterm neonates had less G-CSF than did those from term neonates or adults. G-CSF mRNA content was low in cells from preterm infants, higher in those from term infants, and highest in those from adults. On the basis of the in vitro studies, we speculated that serum G-CSF concentrations might be less elevated in neutropenic neonates than in neutropenic adults. Indeed, serum concentrations were relatively low in all nonneutropenic subjects; 92 +/- 34 pg/mL (mean +/- SEM) in 10 preterm neonates, 114 +/- 21 pg/mL in 16 term neonates, and 45 +/- 13 pg/mL in 11 healthy adults. Serum concentrations were not elevated in 7 neutropenic neonates (39 +/- 17 pg/mL) but were in 8 neutropenic adults (2101 +/- 942 pg/mL, P < .05 v healthy adults). Other studies suggested that the lower G-CSF production in neonates is not counterbalanced by a heightened sensitivity of G-CSF--responsive progenitors to G-CSF. Therefore, we speculate that newborn infants, particularly those delivered prematurely, generate comparatively low quantities of G-CSF after inflammatory stimulation, and that this might constitute part of the explanation for their defective upregulation of neutrophil production and function during infection.
One percent of human circulating B lymphocytes are capable of producing the natural anti-Gal antibody
Authors: Galili U , Anaraki F , Thall A , Hill-Black C , Radic M 
Published: October 2019

Abstract
The natural anti-Gal antibody constitutes 1% of circulating IgG in humans and interacts specifically with the carbohydrate epitope Gal alpha 1–3Gal beta 1–4GlcNAc-R (the alpha-galactosyl epitope). In view of the unusually large amounts of this antibody in the serum, it was of interest to determine the proportion of circulating B lymphocytes capable of synthesizing anti-Gal. For this purpose, blood B lymphocytes were incubated with Epstein-Barr virus (EBV) and plated in microtiter wells. Proliferation of the EBV transformed B lymphocytes was readily visible after 3 weeks of incubation. The supernatants from wells containing proliferating B-lymphoid clones were assayed for anti-Gal by an agglutination assay with rabbit red blood cells and the specificity of the agglutinating antibodies was further confirmed by their interaction with synthetic oligosaccharides and by enzyme-linked immunosorbent assay with glycoproteins. Approximately 5% of the wells contained anti-Gal antibodies. Limiting dilution studies and IgH gene rearrangement patterns suggested that each well contained an average of five proliferating B-lymphoid clones. Thus, it is concluded that approximately 1% of circulating B lymphocytes are capable of producing anti-Gal. The proportion of anti-Gal--producing lymphoid clones exceeds by fourfold that of clones producing anti-blood group A or anti-blood group B antibodies. Individual anti-Gal clones display fine variations in their combining site, as indicated by their differential interaction with alpha-galactosyl epitopes on glycolipids and on N-linked carbohydrate chains of glycoproteins. The high frequency of precursor B lymphocytes capable of producing anti-Gal, found in every individual and the restricted specificity of this antibody to alpha-galactosyl epitopes, potentially makes anti-Gal--producing lymphocytes an effective system for studying human Ig genes involved in the natural immune response to structurally defined haptens.
Interferon-gamma antagonizes interleukin-6-induced expression of interleukin-4 receptors in murine myeloid cells by a transcriptional mechanism
Authors: Ruhl S , Feldman GM , Akahane K , Pluznik DH 
Published: October 2019

Abstract
The murine myeloid leukemia cell line M1 induced by interleukin-6 (IL- 6) is a model system to study the differentiation of blast cells to mature macrophages. We have recently shown that IL-6 induces the expression of the IL-4 receptor (IL-4R) in these cells. In the present study we investigate the mechanism of action of interferon-gamma (IFN- gamma), an antagonist of IL-4 in numerous cells and a cofactor in both induction and suppression of myelopoiesis, on the expression of IL-4R. Flow cytometry shows that IFN-gamma downregulates the IL-6-induced expression of IL-4R whereas it has no such effect on the high-affinity receptors for monomeric IgG2a (Fc gamma RI). As demonstrated by Scatchard analysis, the number of IL-4R decreases by more than 50% after IFN-gamma treatment whereas the receptor affinity remains unchanged. Northern analysis shows that this decrease is paralleled by a decrease in IL-4R mRNA but not Fc gamma RI or lysozyme mRNA. Nuclear run-on analysis shows that IFN-gamma suppresses the IL-6-induced transcription of the IL-4R gene, whereas actinomycin-D chase experiments showed no change of IL-4R mRNA stability. Furthermore, the production of soluble IL-4R protein is suppressed by IFN-gamma as well. These data explain how IL-4R can be modulated by IFN-gamma in myeloid cells and are consistent with the myelosuppressive capacity of IFN- gamma.
Exogenous tat protein activates human endothelial cells [see comments]
Authors: Hofman FM , Wright AD , Dohadwala MM , Wong-Staal F , Walker SM 
Published: October 2019

Abstract
tat protein, a human immunodeficiency virus (HIV) gene product that functions as a transactivator for HIV replication, is known to be secreted extracellularly by infected cells. To determine the potential role of tat in the dissemination of HIV into extravascular tissue, this protein was examined for its ability to activate human endothelial cells. The results show that tat does indeed stimulate endothelial cells. This is evidenced by their expression of the endothelial- leukocyte adhesion molecules, E-selectin, critical for the initial binding of leukocytes to the blood vessel wall, and their increased synthesis of interleukin-6 (IL-6), a cytokine known to enhance endothelial cell permeability. Furthermore, tat acts synergistically with low concentrations of tumor necrosis factor-alpha to enhance IL-6 secretion. These data suggest that extracellular tat protein secreted or released into the microenvironment may contribute significantly to the determination of specific sites of leukocyte binding to blood vessels, to transmigration into tissue, and to eventual dissemination of HIV-infected cells or free virions into tissue.