bluuebunny/crossref_metadata_2025 huggingface dataset:
Human monocytes bind to two cytokine-induced adhesive ligands on cultured human endothelial cells: endothelial-leukocyte adhesion molecule-1 and vascular cell adhesion molecule-1
Authors: Carlos T , Kovach N , Schwartz B , Rosa M , Newman B , Wayner E , Benjamin C , Osborn L , Lobb R , Harlan J
Published: October 2019

Vascular cell adhesion molecule-1 (VCAM-1) and endothelial-leukocyte adhesion molecule-1 (ELAM-1) are adhesive proteins induced on endothelium by cytokines. We examined the contribution of these adhesive proteins to human peripheral blood monocyte adherence to endothelium using transfected Chinese hamster ovary (CHO) cells stably expressing these proteins and monoclonal antibodies (MoAbs) to ELAM-1, VCAM-1, or CD49d/CD29 (VLA-4), the leukocyte receptor for VCAM-1. Monocytes bound to CHO cells transfected with cDNA of ELAM-1 or VCAM-1. Binding to ELAM-1 was inhibited by MoAb to ELAM-1 and binding to VCAM-1 was inhibited by MoAb to VCAM-1 or the alpha-chain of very late activation antigen-4 (VLA-4) (CD49d). Additive inhibition of adherence to unstimulated human umbilical vein endothelium (HUVE) was observed when monocytes were pretreated with both MoAb to CD49d and MoAb to CD18, the common beta-chain of the leukocyte beta 2 integrin receptors. Adherence of monocytes to HUVE stimulated by recombinant human tumor necrosis factor-alpha was not reduced by MoAbs to CD18, CD49d, or ELAM- 1 when used singly, but combinations of these MoAbs produced significant inhibition. We conclude that multiple receptor-ligand systems are involved in monocyte adherence to endothelium.
Antilymphocytic antibodies and marrow transplantation. XIV. Antibody- induced suppression of graft-versus-host disease in C3-decomplemented mice differentiates two T-cell-depletion pathways
Authors: Thierfelder S , Mysliwietz J , Hoffmann-Fezer G , Kummer U
Published: October 2019

Remarkable differences in the suppression of graft-versus-host disease (GVHD) have been found for anti-Thy-1 antibodies to relate to (1) antigen density and antibody coating on the target cells, (2) antibody isotype, and (3) uptake of complement subcomponent C1q. Regarding (2) and (3) we now demonstrate that depletion of the third complement component C3 by cobra venom factor (CVF) differentiates two T-cell elimination pathways in mice: four rat IgG2c anti-Thy-1 monoclonal antibodies (MoAbs) with low uptake of mouse C1q lost most of their T- cell-depleting and consequently GVHD-preventing effect in C3-depleted H2 IA incompatible semiallogeneic (C57BL/6xCBA)F1 mice. In contrast, eight rat IgG2b, mouse IgG2a, and 2b anti-Thy-1 MoAbs with high affinity for C1q still remained strongly T-cell-depleting and prevented GVHD even in fully mismatched CBA mice depleted of C3. In conjunction with our observation that anti-Thy-1 MoAbs also suppress GVHD in C5- deficient AKR mice, we conclude that complete complement activation until T-cell lysis is not required for our antibodies to be effective in vivo. Activation, but only until deposition of C3b on target-cells for opsonisation via C3b receptors, is necessary with the less immunosuppressive anti-Thy-1 IgG2c isotype with low affinity for C1q. Mouse C1q uptake and C3/C4 deposition on target cells were measured with labeled antibodies and localized in T-cell areas. Interestingly, not even activation until C3b is necessary with the most immunosuppressive C1q-high-affine isotypes. As far as the latter is concerned, we discuss whether elimination of antibody-coated cells via Fc receptors is enhanced by binding to C1q-receptors and/or by intercalating C1q expressed on macrophages.
In vitro effects of hematopoietic growth factors on the proliferation, endoreplication, and maturation of human megakaryocytes
Authors: Debili N , Hegyi E , Navarro S , Katz A , Mouthon MA , Breton-Gorius J , Vainchenker W
Published: October 2019

A liquid culture technique was used to study regulation of human megakaryocytopoiesis in vitro. Low-density cells from adult bone marrow were cultured in the presence of normal plasma, plasma from patients with aplastic marrows (AP), recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and interleukin-3 (IL-3). Megakaryocytes (MK) were studied at day 10 of culture by a two-color staining technique using a pool of monoclonal antibodies for their identification and propidium iodide to label DNA. Their ploidy distribution was analyzed by flow cytometry. In some experiments cytoplasmic maturation was also studied by ultrastructural techniques. Normal plasma provides a low number of MK with a ploidy distribution including 8 N and 16 N MK. AP promoted in a dose-dependent manner proliferation of MK and some batches favored endoreplication. This effect was clearly demonstrated when ploidy distribution was compared between normal plasma and AP on parallel marrow cultures. However, ploidy distribution was shifted toward low values compared with uncultured MK. rhGM-CSF had no significant effect on these two parameters. In contrast, rhIL-3 from 0.1 U/mL to 100 U/mL had a proliferative effect but was unable to induce endoreplication. Furthermore, when associated with AP it totally abrogated the effect of AP on endoreplication because in most experiments more than 90% of MK were 2 N and 4 N. This effect was also observed when rhIL-3 was added after 7 days of culture (when it has little proliferative effects). Studies of the maturation of MK grown with rhIL-3 indicate that the majority were small mature cells synthesizing alpha-granules and demarcation membranes. The effect of AP on MK proliferation and endoreplication was not related to IL-6 because its IL-6 content was identical to that of normal plasma and its neutralization did not modify these parameters. In conclusion, this study indicates that liquid culture technique in association with flow cytometry could be a powerful tool in identifying the humoral regulators of human megakaryocytopoiesis.
Developmental hematopoiesis in normal human fetal blood
Authors: Forestier F , Daffos F , Catherine N , Renard M , Andreux JP
Published: October 2019

Using an easy and safe procedure for fetal blood sampling in utero, we studied 3,415 fetuses for prenatal diagnosis. Retrospectively, 2,860 normal blood samples, performed from the 18th week of gestation to the end of pregnancy, were selected. Differentials were evaluated in 732 cases. Burst-forming unit erythroid (BFU-E) and erythropoietin (Epo) were measured in 27 and 163 cases, respectively. Total nucleated cell and platelet counts did not change from the 18th to the 30th week of gestation. The lymphocytes represented the main population and the decrease of normoblastic cells made up for the increase in neutrophils. The increase of red blood cells and hemoglobin was substantial during the studied period. At mid trimester threefold more BFU-E were obtained than at birth. Epo levels remained stable throughout the pregnancy and no correlation was found between Epo and gestational age. These normal values of fetal erythropoiesis will improve our knowledge of physiology and provide a better insight into developmental hematopoiesis.
Platelet activation by fMLP-stimulated polymorphonuclear leukocytes: the activity of cathepsin G is not prevented by antiproteinases
Authors: Evangelista V , Rajtar G , de Gaetano G , White JG , Cerletti C
Published: October 2019

Human polymorphonuclear leukocytes (PMN) activated by fMLP (in the presence of CaCl2, fibrinogen, and cytochalasin B) were able to induce aggregation, cytoplasmic Ca2+ increase, and thromboxane A2 production in coincubated autologousplatelets. Cell-free supernatants prepared from n-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated PMN were able also to induce platelet activation. Antibodies against cathepsin G and different serin protease inhibitors completely suppressed the activity of PMN-derived supernatants, indicating that cathepsin G is the major platelet activator released by PMN in our system. However, antiproteinases only partially affected platelet activation induced by PMN in mixed cell suspensions. Superoxide dismutase and catalase added to the cell suspension did not affect platelet activation nor potentiated serin protease inhibitors, making a role for short-lived oxygen radicals in our experimental system unlikely. Electron microscopic observation of stirred mixed cell suspensions preincubated for 2 minutes at 37 degrees C before stimulation showed a close PMN- platelets contact without any morphologic or biochemical event suggesting platelet activation. Preincubation of the cells without stirring to minimize PMN-platelet interaction before stimulation did not modify subsequent aggregation and platelet cytoplasmic Ca2+ increase in control samples. However, in this condition trypsin inhibitor from soybean completely prevented PMN-induced platelet activation. In samples preincubated without stirring in the presence of the antiproteinase, activated PMN stuck together but platelets preserved their discoid shape and did not appear significantly activated. We propose that membrane-to-membrane contact could create a microenvironment in which cathepsin G, discharged from stimulated PMN on adherent platelets, is protected from antiproteinases.
Tissue inhibitor of metalloproteinases-1 (TIMP-1) RNA is expressed at elevated levels in malignant non-Hodgkin's lymphomas
Authors: Kossakowska AE , Urbanski SJ , Edwards DR
Published: October 2019

Secreted metalloproteinases (MPs) and their specific inhibitors (TIMPs, tissue inhibitors of MPs) are important mediators of extracellular matrix metabolism. Previous studies have linked either excessive MP release or reduced TIMP-1 production to the invasive and metastatic phenotypes of cancer cells. In the present study we investigated the relationship between the expression of TIMP-1 and the clinical behavior of 28 non-Hodgkin's lymphomas. Northern blot analysis showed that levels of TIMP-1 mRNAs correlated directly with clinical aggressiveness: tumors in the high-grade category contained the highest levels of TIMP-1 transcripts approaching those found in maximally growth factor-stimulated fibroblasts in vitro. In situ hybridization localized the TIMP-1 expression to stromal cells of endothelial and fibroblastic origin. In contrast, transcripts hybridizing with metalloproteinase gene probes (interstitial collagenase and 72-Kd type IV collagenase) were expressed at very low levels in malignant lymphomas and their expression was not coordinately regulated with that of TIMP-1. The majority of tumors expressed either interstitial collagenase or 72-Kd type IV collagenase, and only a small number expressed both. Interstitial collagenase transcripts were only detected in high-grade tumors. The relative levels of TIMP-1 expression did not correlate with the degree of fibrosis of the tumors. Our data suggest the importance of tumor-stromal interactions in non-Hodgkin's lymphomas, and moreover, our results indicate a possible relationship between high-level, localized expression of TIMP-1 and the malignant phenotype of high-grade advanced-stage lymphomas.
Impact of pretransplant conditioning and donor T cells on chimerism, graft-versus-host disease, graft-versus-leukemia reactivity, and tolerance after bone marrow transplantation
Authors: Truitt RL , Atasoylu AA
Published: October 2019

Graft rejection, mixed chimerism, graft-versus-host disease (GVHD), leukemia relapse, and tolerance are interrelated manifestations of immunologic reactivity between donor and host cells that significantly affect survival after allogeneic bone marrow transplantation (BMT). In this report, a mouse model of BMT, in which the donor and host were compatible at the major histocompatibility complex (MHC), was used (1) to examine the interrelationship of pretransplant conditioning and T- cell content of donor BM with regard to lymphoid chimerism and GVHD and (2) to determine how these factors affected graft-versus-leukemia (GVL) reactivity and donor-host-tolerance. AKR (H-2k) host mice were administered optimal or suboptimal total body irradiation (TBI) as pretransplant conditioning followed by administration of BM cells from B10.BR (H-2k) donor mice with or without added spleen cells as a source of T lymphocytes. Transplanted mice were injected with a supralethal dose of AKR leukemia cells 20 and 45 days post-BMT to assess GVL reactivity in vivo. The pretransplant conditioning of the host and T- cell content of the donor marrow affected the extent of donor T-cell chimerism and the severity of GVH disease. GVL reactivity was dependent on transplantation of mature donor T cells and occurred only in complete chimeras. Transplantation of T-cell-deficient BM resulted in the persistence of host T cells, ie, incomplete donor T-cell chimerism, even when lethal TBI was used. Mixed chimerism was associated with a lack of GVL reactivity, despite the fact that similar numbers of donor T cells were present in the spleens of mixed and complete chimeras. In this model, moderate numbers of donor T cells facilitated complete donor T-cell engraftment, caused only mild GVHD, and provided a significant GVL effect without preventing the subsequent development of tolerance after conditioning with suboptimal TBI. In contrast, severe, often lethal, GVHD developed when the dose of TBI was increased, whereas tolerance and no GVH/GVL reactivity developed when the T-cell content of the marrow was decreased.
Autologous bone marrow transplantation in 69 patients with a history of low-grade B-cell non-Hodgkin's lymphoma
Authors: Freedman AS , Ritz J , Neuberg D , Anderson KC , Rabinowe SN , Mauch P , Takvorian T , Soiffer R , Blake K , Yeap B
Published: October 2019

Sixty-nine patients with a history of low-grade B-cell non-Hodgkin's lymphoma (NHL) in sensitive relapse or incomplete first remission underwent high-dose chemoradiotherapy and anti-B-cell monoclonal antibody (MoAb)-treated autologous bone marrow transplantation (ABMT). At ABMT, 51 patients had low-grade histology and 18 patients had a history of low-grade NHL that had undergone histologic transformation to a higher-grade NHL. Before ABMT, only 20 of the 51 low-grade patients and 10 of the 18 patients with transformed histologies were in complete remission. Moreover, at the time of marrow harvest, 24 of the low-grade and eight of the transformed histology patients had histologic evidence of lymphoma cells infiltrating the marrow. Following high-dose therapy, only one acute, in-hospital death was observed. There was no significant difference in the disease-free survival (DFS) between patients with low-grade and patients with transformed histologies. Among patients with low-grade NHL, the patients in complete remission before ABMT experienced significantly longer DFS than those in partial remission (P less than .05). This preliminary study suggests that some patients with relapsed low-grade NHL may experience prolonged DFS following high-dose ablative therapy.
Toxicity and immunomodulatory effects of interleukin-2 after autologous bone marrow transplantation for hematologic malignancies
Authors: Higuchi CM , Thompson JA , Petersen FB , Buckner CD , Fefer A
Published: October 2019

Autologous bone marrow transplantation (ABMT) for advanced hematologic malignancies is associated with high relapse rates. Interleukin-2 (IL- 2) and lymphokine-activated killer (LAK) cells represent a potentially non-cross-resistant therapeutic modality that might prevent or delay relapses if used early after ABMT at a time when the tumor burden is minimal. However, high-dose chemoradiotherapy and ABMT might increase patients' susceptibility to IL-2 toxicity, and might interfere with immunologic responses to IL-2 in vivo. Therefore, to determine safety, tolerance, and immunomodulatory effects of IL-2 therapy early after ABMT, IL-2 was administered by continuous intravenous infusion to 16 patients 14 to 91 days (median, 33) after ABMT for acute leukemia, lymphoma, or multiple myeloma. Patients were sequentially assigned to escalating IL-2 “induction” doses (0.3 to 4.5 x 10(6) U/m2/d, days 1 to 5), and all patients received a nonescalating IL-2 “maintenance” dose (0.3 x 10(6) U/m2/d, days 12 to 21). Most patients exhibited mild to moderate fever, nausea, diarrhea, and/or skin rash with IL-2 infusions. The maximum tolerated “induction” dose was 3.0 x 10(6) U/m2/d; dose- limiting toxicities were hypotension and thrombocytopenia. All toxicities reversed on stopping the IL-2 infusions, and all patients completed “maintenance.” Postinfusion lymphocytosis was exhibited by patients at all IL-2 dose levels. With the higher IL-2 doses, increased percentages of patients' PBMC expressed CD16 and CD56, with augmented lysis of K562 and Daudi, reflecting the induction of natural killer and circulating LAK effector activities. Increased LAK precursor activity was exhibited by patients at all IL-2 dose levels. Thus, the IL-2 therapy regimen was safely tolerated after ABMT, and pronounced immunomodulatory effects were observed with the higher IL-2 doses. These studies support the planned use of IL-2 and LAK cells after ABMT in an attempt to reduce relapses of advanced hematologic malignancies.
Erythropoietin receptor characteristics on primary human erythroid cells
Authors: Broudy VC , Lin N , Brice M , Nakamoto B , Papayannopoulou T
Published: October 2019

Erythropoietin (EP) exerts its effects on erythropoiesis by binding to a cell surface receptor. We examined EP receptor expression during normal human erythroid differentiation and maturation from the burst- forming unit-erythroid (BFU-E) to the reticulocyte level. In contrast to previous studies, we assessed EP receptor number and affinity in erythroid precursors immunologically purified from fresh bone marrow aspirates or fetal liver samples and in reticulocytes purified from peripheral blood. EP receptors were quantitated by equilibrium binding experiments with 125I EP. We found that purified primary erythroblasts from both adult and fetal sources exhibited a single high-affinity (kd 100 pmol/L) binding site for EP under our experimental conditions, and 135 or 250 receptors per cell, respectively. Reticulocytes were devoid of EP receptors. We compared these data to in vitro-derived BFU-E progeny at both early and late stages of maturation. Cultured BFU-E progeny also displayed a single class of receptors of slightly lower affinity (210 to 220 pmol/L). Preparations enriched in colony-forming units-erythroid (CFU-E) and proerythroblasts (day 9 BFU-E progeny) displayed approximately 1,100 receptors per cell, whereas populations containing mature erythroblasts (day 14 BFU-E progeny) exhibited approximately 300 receptors per cell. Furthermore, information from binding experiments was complemented by autoradiography in both enriched BFU-E preparations, cultured BFU-E progeny (days 9 and 14), and marrow mononuclear cells. These studies are consistent with a peak in EP receptor expression at the CFU-E/proerythroblast stage and a decrease with further maturation to undetectable levels at the reticulocyte stage. These data examining EP receptor characteristics on freshly isolated erythroid precursor cells complement previous data on EP receptor biology using culture-derived erythroblasts.
Identification and comparison of CD34-positive cells and their subpopulations from normal peripheral blood and bone marrow using multicolor flow cytometry
Authors: Bender JG , Unverzagt KL , Walker DE , Lee W , Van Epps DE , Smith DH , Stewart CC , To LB
Published: October 2019

Four-color flow cytometry was used with a cocktail of antibodies to identify and isolate CD34+ hematopoietic progenitors from normal human peripheral blood (PB) and bone marrow (BM). Mature cells that did not contain colony forming cells were resolved from immature cells using antibodies for T lymphocytes (CD3), B lymphocytes (CD20), monocytes (CD14), and granulocytes (CD11b). Immature cells were subdivided based on the expression of antigens found on hematopoietic progenitors (CD34, HLA-DR, CD33, CD19, CD45, CD71, CD10, and CD7). CD34+ cells were present in the circulation in about one-tenth the concentration of BM (0.2% v 1.8%) and had a different spectrum of antigen expression. A higher proportion of PB-CD34+ cells expressed the CD33 myeloid antigen (84% v 43%) and expressed higher levels of the pan leukocyte antigen CD45 than BM-CD34+ cells. Only a small fraction of PB-CD34+ cells expressed CD71 (transferrin receptors) (17%) while 94% of BM-CD34+ expressed CD71+. The proportion of PB-CD34+ cells expressing the B-cell antigens CD19 (10%) and CD10 (3%) was not significantly different from BM-CD34+ cells (14% and 17%, respectively). Few CD34+ cells in BM (2.7%) or PB (7%) expressed the T-cell antigen CD7. CD34+ cells were found to be predominantly HLA-DR+, with a wide range of intensity. These studies show that CD34+ cells and their subsets can be identified in normal PB and that the relative frequency of these cells and their subpopulations differs in PB versus BM.
Stimulatory effects of granulocyte colony-stimulating factor on colony- forming units-spleen (CFU-S) differentiation and pre-CFU-S proliferation in mice
Authors: Tanaka T , Suda T , Suda J , Inoue T , Hirabayashi Y , Hirai H , Takaku F , Miura Y
Published: October 2019

Granulocyte colony-stimulating factor (G-CSF) was reported to increase the number of colony-forming units-spleen (CFU-S) and multilineage colonies as well as myeloid-committed cells. We investigated the effects of G-CSF on myeloid progenitors and primitive stem cells in a mouse bone marrow transplantation (BMT) system. Lethally irradiated mice received BM cells from untreated or 5-fluorouracil-treated mice, and then were administered G-CSF or carrier buffer (control) for 5 days from immediately after BMT. A pre-CFU-S assay was performed by the repeated transplantation of BM cells from the first BMT recipients to other mice. By the method of polymerase chain reaction, most of the spleen colonies in the secondary recipients were confirmed to be derived from the first donors. G-CSF did not increase the peripheral white blood cell count significantly, but did increase the number of immature myeloid cells and granulocyte-macrophage colony-forming cells in the BM. The number of erythroid cells in the BM was initially suppressed and then increased by G-CSF treatment. In addition, the pre- CFU-S assay showed an increase in pre-CFU-S cells due to G-CSF administration. The number of spleen colonies of first BMT recipients did not increase, but a higher percentage of them were committed to a certain lineage by G-CSF treatment. These findings suggest that G-CSF has important roles in the early stages of hematopoiesis.
DNA synthesis in human bone marrow is circadian stage dependent
Authors: Smaaland R , Laerum OD , Lote K , Sletvold O , Sothern RB , Bjerknes R
Published: October 2019

Fraction of human bone marrow (BM) cells in DNA synthesis has been studied by sampling BM from the sternum or the iliac crests every 4 hours during one 24-hour period in 16 healthy male volunteers. Three of the subjects underwent the sampling procedure twice, resulting in 19 24- hour profiles. The percentage of cells in DNA synthesis measured by flow cytometry demonstrated a large variation along the circadian time scale for each 24-hour profile, with a range of variation from 29% to 339% from lowest to highest value. Seventeen profiles (89.5%) had the highest DNA synthesis during waking hours between 08:00 hours and 20:00 hours, and the lowest percentage of cells in DNA synthesis between 00:00 hours and 04:00 hours. The mean value of the lowest DNA synthesis for each 19 24-hour period was 8.7% +/- 0.6%, while the mean value of the highest DNA synthesis was 17.6% +/- 0.6%, ie, a twofold difference. There was no difference in DNA synthesis between winter and summer. A significantly higher DNA synthesis was demonstrated for samples obtained from sternum as compared with the iliac crests, but the same circadian pattern was demonstrated for both localizations. By taking circadian stage-dependent variations in DNA synthesis into account it may be possible to reduce BM sensitivity to cytotoxic chemotherapy, to increase the effect of hematopoietic growth factors as well as increase the fraction of proliferating cells with careful selection of time of day for harvesting BM cells for auto- or allografting.
The importance of N- and O-linked oligosaccharides for the biosynthesis and in vitro and in vivo biologic activities of erythropoietin
Authors: Wasley LC , Timony G , Murtha P , Stoudemire J , Dorner AJ , Caro J , Krieger M , Kaufman RJ
Published: October 2019

Erythropoietin (EPO) plays a critical role in stimulating the proliferation and differentiation of erythroid precursor cells. EPO is heavily glycosylated with three asparagine (N)-linked tetraantennary oligosaccharides that may contain N-acetyl-lactosamine repeats and a single serine (O)-linked oligosaccharide. EPO expressed in Chinese hamster ovary cells exhibits biologic properties and amino acid and carbohydrate composition similar to natural urinary EPO. The importance of the complex N-linked and the O-linked carbohydrate was studied by expressing EPO in cells that are deficient in UDP-galactose/UDP-N- acetylgalactosamine 4-epimerase activity. In these cells, the ability to add galactose and N-acetylgalactosamine to glycoproteins can be controlled by the addition of these sugars to the culture medium. The results demonstrate that a block in O-linked glycosylation and/or the ability to process N-linked carbohydrate to completion does not alter EPO secretion. EPO produced without O-linked carbohydrate exhibits normal in vitro and in vivo biologic activity and in vivo clearance. However, EPO produced with incompletely processed N-linked oligosaccharides exhibits normal in vitro activity but is at least 500- fold less effective in stimulating erythropoiesis in vivo. Studies on the survival of bioactive EPO remaining in the circulation demonstrated that EPO with incomplete N-linked oligosaccharides exhibits a sevenfold increased rate of clearance. However, this increased clearance may not fully account for the 500-fold loss of in vivo activity. These results suggest a potentially important unique requirement for appropriate complex N-linked oligosaccharides for the intrinsic biologic activity of EPO in vivo.
Genotype establishments for protein C deficiency by use of a DNA polymorphism in the gene
Authors: Yamamoto K , Tanimoto M , Matsushita T , Kagami K , Sugiura I , Hamaguchi M , Takamatsu J , Saito H
Published: October 2019

During the course of structural gene analyses for protein C deficiency, we have confirmed that a T or G nucleotide variation is present at exon 6 of the protein C gene. This single-base substitution was located at the third nucleotide coding for Ser (TCT) at 99 residue, and neither produces an amino acid substitution nor creates a new restriction enzyme site. By using mutagenic primers that could introduce A instead of G at the third nucleotide 3′ to the de novo polymorphic site, we have created the polymorphic Xba I site (T/CTAGA) in a more-frequent allele. Polymerase chain reaction using these mutagenic primers and subsequent Xba I digestion of 20 normal Japanese genomic samples showed that the frequency of this new sequence polymorphism designated as PC- 493 was 0.18 and that the estimated heterozygosity rate was 28.9%. In Caucasians, the frequency of this polymorphism was 0.25, and a significant difference did not exist between Japanese and Caucasian populations. The examination of the haplotype inter-relationships with PC-493 and the Msp I polymorphism 5′ to the protein C gene established that PC-493 gave a 16.7% chance of new information per individual for people who were previously homozygous for the Msp I polymorphism. We have performed a family study of the protein C-deficient pedigree using this sequence polymorphism, and found that the PC-493 DNA polymorphism was a useful marker for tracing the affected gene in protein C- deficient family members.
Inhibitor of the thrombin time in systemic amyloidosis: a common coagulation abnormality
Authors: Gastineau DA , Gertz MA , Daniels TM , Kyle RA , Bowie EJ
Published: October 2019

Patients with primary systemic amyloidosis (AL) often experience bleeding, and we report a newly recognized coagulation abnormality in AL. Of 103 patients with primary systemic AL studied over 2 years, 41 had prolongation of the thrombin time (range, 25 to 46 seconds; normal, less than 22 seconds) and reptilase time (range, 17 to 39 seconds; normal, 14 to 16 seconds). The fibrinogen from the plasma of 36 patients was precipitated by beta-alanine and diluted to a concentration of approximately 200 mg/dL. The thrombin times of the precipitated fibrinogens were normal in 34 patients, implying that an inhibitor was responsible for the abnormal tests. The addition of patient fibrinogen-free plasma to normal plasma prolonged the thrombin times, and this result confirmed the presence of an inhibitor. The inhibitor is more likely to be present in patients with nephrotic syndrome (20 of our patients) and congestive heart failure (six). A circulating monoclonal protein (24 patients), the presence of amyloid liver involvement (eight), and the presence of amyloid neuropathy (nine) were not predisposing factors. Only one patient had deficiency of factor X. We conclude that inhibition of fibrinogen conversion to a fibrin clot rather than dysfibrinogenemia is the cause of the prolonged thrombin time in primary systemic AL.
Alpha 2-macroglobulin-kallikrein complexes detect contact system activation in hereditary angioedema and human sepsis
Authors: Kaufman N , Page JD , Pixley RA , Schein R , Schmaier AH , Colman RW
Published: October 2019

Activation of the contact system has been documented in severe sepsis and hereditary angioedema, but a sensitive, specific, and quantitative assay for assessing the degree of involvement of this proteolytic enzyme cascade is not yet available. We have developed a quantitative sandwich enzyme-linked immunosorbent assay (ELISA) for the alpha 2- macroglobulin-kallikrein (alpha 2M-Kal) complex using an F(ab')2 derivative of a monospecific polyclonal antibody against alpha 2 M as the capture antibody and a unique murine monoclonal antibody, 13G11, against the heavy chain of kallikrein as the detector antibody. The assay does not detect complexes in normal plasma but reacts with complexes generated by activating normal plasma with dextran sulfate at 4 degrees C in a range of 5 to 375 nmol/L. A close correlation of the ELISA with an amidolytic assay for alpha 2M-Kal was documented. Patients with sepsis syndrome but negative bacterial blood cultures did not show elevated plasma complexes, whereas a majority of those with positive blood cultures did show modest elevation and a single patient with septic shock showed a very high level of alpha 2M-Kal complex. Similarly, a patient with classic hereditary angioedema (HAE) showed increased concentration of complexes on three separate occasions during attacks but normal levels between attacks. Two other HAE patients did not show elevated levels at quiescent periods. The ELISA for alpha 2M- Kal appears to be sensitive, specific, and quantitative, and it can be used to reflect the degree of contact system activation in human sepsis and in HAE attacks.
'Role of bone marrow stromal cells in the growth of human multiple myeloma
Authors: Caligaris-Cappio F , Bergui L , Gregoretti MG , Gaidano G , Gaboli M , Schena M , Zallone AZ , Marchisio PC
Published: October 2019

We have verified the hypothesis that multiple myeloma (MM) may be disseminated by circulating clonogenic cells that selectively home to the bone marrow (BM) to receive the signal(s) leading to proliferation, terminal differentiation, and production of the osteoclast activating factors. Long-term cultures of stromal cells have been developed from the BM of nine patients with MM. These cells were mostly fibroblast- like elements, interspersed with a proportion of scattered macrophages and rare osteoclasts. BM stromal cells were CD54+, produced high levels of interleukin-6 (IL-6) and measurable amounts of IL-1 beta, and were used as feeder layers for autologous peripheral blood mononuclear cells (PBMC). After 3 weeks of cocultures, monoclonal B lymphocytes and plasma cells, derived from PBMC, developed and the number of osteoclasts significantly increased. Both populations grew tightly adherent to the stromal cell layer and their expansion was matched by a sharp increase of IL-6 and by the appearance of IL-3 in the culture supernatant. These data attribute to BM stromal cells a critical role in supporting the growth of B lymphocytes, plasma cells, and osteoclasts and the in vivo dissemination of MM.
Lipid hydroperoxides permit deformation-dependent leak of monovalent cation from erythrocytes
Authors: Sugihara T , Rawicz W , Evans EA , Hebbel RP
Published: October 2019

Subtle peroxidative perturbation of normal red blood cells (RBC) using t-butylhydroperoxide creates a leak pathway for monovalent cations that is reversibly activated by cell deformation. To determine what factor promotes expression of this unique membrane defect, we have dissected “peroxidation” into components that can be evaluated separately by comparing K leak from suitably modified RBC during elliptical deformation and parallel control incubation. Selective introduction of phospholipid hydroperoxides into normal RBC membranes successfully induces a deformation-dependent leak pathway having the same phenomenology as that previously documented for cells treated with t- butylhydroperoxide itself (fully recoverable; calcium-independent; inhibited at lower pH; K efflux balanced by Na influx). This leak pathway occurs in the absence of detectable secondary peroxidative change and appears to reflect a direct influence of lipid hydroperoxide. Using micropipette examination of vesicular bilayers reconstituted from RBC lipid extracts, we find that lipid from peroxidized RBC exhibits only a slight tendency to be less cohesive than normal lipid, apparently precluding isolated lipid properties as an explanation for altered permeability barrier function. However, addition of a hydrophobic membrane-spanning peptide to these same lipids significantly diminishes bilayer cohesion, an effect that is exacerbated further by the presence of peroxidized lipid. These observations suggest that lipid hydroperoxide is a necessary, but perhaps not sufficient, factor for induction of this unique leak pathway. Our results may be relevant to the abnormal cation homeostasis of sickle RBC in which deformation of an oxidatively perturbed membrane occurs during the sickling phenomenon.
Induction of the paroxysmal nocturnal hemoglobinuria phenotype in normal human erythrocytes: effects of 2-aminoethylisothiouronium bromide on membrane proteins that regulate complement
Authors: Ezzell JL , Wilcox LA , Bernshaw NJ , Parker CJ
Published: October 2019

To investigate the mechanism by which treatment of normal human erythrocytes with the sulfhydryl reagent 2-aminoethylisothiouronium bromide (AET) induces susceptibility to complement mediated lysis, the effects of AET on the structural and functional integrity of decay accelerating factor (DAF), membrane inhibitor of reactive lysis (MIRL), and complement receptor type 1 (CR1) were examined. Following treatment with AET, erythrocyte MIRL and CR1 were no longer recognized in situ by antibodies, and antibody binding to DAF was diminished by approximately 50%. These studies indicated that the structural integrity of the three complement regulatory proteins was either partially (DAF) or completely (MIRL and CR1) disrupted by AET. Subsequent experiments showed that functional inactivation paralleled the structural disruption. Treatment of normal erythrocytes with AET induced susceptibility to cobra venom factor-initiated hemolysis, indicating that the functional activity of MIRL had been destroyed. The capacity of erythrocyte CR1 to serve as a cofactor for factor I-mediated cleavage of iC3b to C3c and C3dg was lost following treatment with AET. C3 convertase activity increase markedly following treatment of erythrocytes with AET, but convertase activity on AET cells was approximately 50% less than that observed when DAF function on normal cells was completely inhibited by antibody. Susceptibility of AET cells to acidified serum lysis was shown to be due primarily to inactivation of MIRL. Unexpectedly, in acidified serum the activity of the amplification C3 convertase of the APC was found to be controlled by MIRL as well as by DAF. These studies show that AET induces susceptibility to complement-mediated lysis by disrupting the structural and functional integrity of membrane constituents that regulate the activity of both the C3 convertases and the membrane attack complex of complement.
Posttransfusion purpura due to an alloantibody reactive with glycoprotein Ia/IIa (anti-HPA-5b)
Authors: Christie DJ , Pulkrabek S , Putnam JL , Slatkoff ML , Pischel KD
Published: October 2019

A 38-year-old woman (JT) was diagnosed with posttransfusion purpura and significant posthysterectomy vaginal bleeding 9 days after the transfusion of 2 U of packed red blood cells. Analysis of JT's serum by a monoclonal antibody-antigen capture enzyme-linked immunosorbent assay method showed the presence of anti-HPA-5b (anti-Bra) antibodies directed against an epitope on platelet glycoprotein (GP) la of the GPIa/IIa complex. The patient's serum immunoprecipitated two proteins from 125I-labeled HPA-5b positive platelets that migrated under both nonreducing and reducing conditions on sodium dodecyl sulfate polyacrylamide gels at molecular weights characteristic of GPIa (150 Kd and 165 Kd, respectively) and GPIIa (120 Kd and 145 Kd, respectively). These bands were not precipitated when 125I-labeled HPA-5b negative platelets were used. Platelet typings performed on JT and her three children showed that the patient was HPA-5b negative and one of her children was HPA-5b positive. Platelets obtained from one of the donors who provided blood for the inciting transfusion also typed as HPA-5b positive. These findings demonstrate that posttransfusion purpura may be induced by antibodies directed against an alloantigenic epitope, namely HPA-5b (Bra), located on GPIa/IIa. Moreover, clinically significant bleeding can be associated with antibody reactions directed against this GP complex.
Erythropoietin mRNA levels are governed by both the rate of gene transcription and posttranscriptional events
Authors: Goldberg MA , Gaut CC , Bunn HF
Published: October 2019

The human hepatoma cell line, Hep3B, synthesizes large quantities of erythropoietin (Epo) mRNA and protein in a regulated manner in response to hypoxia and cobaltous chloride (CoCl2). To further understand the regulation of Epo gene expression, we studied the effects of hypoxia and CoCl2 on the rate of Epo gene transcription. While Northern blot analyses showed that steady-state Epo mRNA levels increase more than 50- fold in response to hypoxia or CoCl2, nuclear run-off experiments demonstrated only a 10-fold increase in Epo gene transcription in response to these stimuli. In the presence of either actinomycin D (Act D) or cycloheximide, the stability of biologically functional Epo mRNA was much greater than that observed in the absence of these agents and much greater than that which has been reported in vivo. These findings suggest that the stability of Epo mRNA is modulated by the transcription and translation of rapidly turning over gene product(s). Thus, Epo mRNA levels are determined by both the rate of gene transcription and posttranscriptional events. These experiments demonstrate a potential pitfall in estimating mRNA half-lives based on Act D chase experiments alone.
Fibrinogen is not synthesized by human megakaryocytes
Authors: Louache F , Debili N , Cramer E , Breton-Gorius J , Vainchenker W
Published: October 2019

The origin of platelet fibrinogen is controversial. It may arise from two sources: (a) exogenously by endocytosis of plasma fibrinogen, or (b) endogenously by synthesis. We explored the second possibility because we previously demonstrated that the first mechanism does occur. Fibrinogen synthesis by human megakaryocytes (MK) was investigated by in situ hybridization and the polymerase chain reaction (PCR) applied to mRNA. MK differentiating from marrow CFU-MK were cultured in suspension. In situ hybridization using the 35S alpha and beta fibrinogen chain anti-sense riboprobes was totally negative in MK in comparison with negative controls (lambda phage and alpha and beta fibrinogen chain sense riboprobes). In contrast, synthesis of fibrinogen was detected by this technique in a hepatoma cell line (HepG 2). Furthermore, mRNA for alpha and beta chains of fibrinogen was not detected by the PCR performed on mRNA from cultured MK enriched to 90% purity, by the immunomagnetic bead technique, even after Southern blotting of the amplified products. In addition, fibrinogen mRNA was undetected in marrow MK and in platelets by the same technique, whereas a specific megakaryocyte gene transcript (GPIb alpha) was easily detected. These observations demonstrate that the only mechanism responsible for the presence of fibrinogen in platelets is endocytosis of fibrinogen from plasma.
Synergistic inhibition by verapamil and quinine of P-glycoprotein- mediated multidrug resistance in a human myeloma cell line model
Authors: Lehnert M , Dalton WS , Roe D , Emerson S , Salmon SE
Published: October 2019

In an effort to develop a clinically useful approach to overcoming P- glycoprotein-mediated multidrug resistance (MDR1), we evaluated combined chemosensitization with verapamil and quinine in a multidrug- resistant (MDR) human myeloma cell line model. In clonogenic assay, verapamil was used at concentrations from 0.1 to 1.0 micrograms/mL, bracketing the plasma levels achieved by oral administration and high- dose intravenous (IV) infusion, respectively. The dose of quinine was held constant at 1.0 micrograms/mL, a plasma concentration readily achieved by oral administration. At each dose level of verapamil tested, the combination with quinine proved more effective than either drug individually in reversing resistance to doxorubicin and vinblastine and synergistic chemosensitizing interaction was observed. Verapamil at 0.1 microgram/mL combined with quinine was capable of restoring sensitivity to doxorubicin fully and reduced resistance to vinblastine as effectively as verapamil alone at 1.0 micrograms/mL. Furthermore, the combination of 1.0 mumol verapamil with 10 mumols quinine increased accumulation and retention of anthracycline in the resistant cells to a greater extent than did either drug individually (P less than .001) and inhibited drug efflux as effectively as verapamil alone at 10 mumols. Our findings suggest that combined chemosensitization with verapamil and quinine may prove useful for overcoming MDR1 in patients with drug-refractory B-cell neoplasms such as multiple myeloma or non-Hodgkin's lymphomas.
Anti-CD33 monoclonal antibody and etoposide/cytosine arabinoside combinations for the ex vivo purification of bone marrow in acute nonlymphocytic leukemia
Authors: Stiff PJ , Schulz WC , Bishop M , Marks L
Published: October 2019

Pharmacologic and immunologic methods of ex-vivo bone marrow (BM) purging for acute nonlymphocytic leukemia (ANLL) were combined to augment the effect of either method alone. Etoposide (VP16; 20 to 30 micrograms/mL) with or without cytosine arabinoside (Ara C; 10 mg/mL) was used in tandem with the anti-CD33 monoclonal antibody (MoAb), MY9, chosen because CD33 is found on the stem cell pool in the majority of patients with ANLL. The agents were tested singly or sequentially, with a 1-hour incubation of the drugs preceding complement-mediated lysis using MY9. VP16 combined with Ara C killed up to 3.9 +/- 0.3 and 5.11 +/- 0.4 logs of the human ANLL cell lines HL60 and K562 at drug concentrations that killed only 1.2 +/- 0.1 logs of normal committed granulocyte/macrophage stem cells (CFU-GM). Adding a single exposure of the MY9 and complement (C′) to the drug-treated cells, greater than 5.4 logs of HL60 were killed. Similar to other pharmacologic agents, no differential kill for clonagenic leukemic cells (colony-forming unit- leukemia; CFU-L) from patients with ANLL was seen for drug only treated blasts versus normal CFU-granulocyte-macrophage (CFU-GM), with less than 1 log CFU-L kill at drug concentrations that spared 1 log of CFU- GM. Similarly, only 1.1 +/- 0.3 logs of ANLL CFU-L were eliminated using MY9 and C′. However, with the sequential VP16/Ara C----MY9 + C′ treatment, synergy was demonstrated and 2.6 +/- 0.3 logs of CFU-L were eliminated. Because CD33 is also found on the normal CFU-GM pool, two- stage long-term BM cultures were performed to determine pluripotent stem cell elimination by the drug/MoAb purging combination. No difference of CFU-GM or BFU-E production at 4 to 6 weeks of culture for VP16/Ara C, MY9 + C′, or VP16/AraC----My9 + C′ treated cells was seen compared with untreated controls indicating sparing of early progenitor cells. Sequential ex vivo treatment of human ANLL CFU-L with VP16/Ara C followed by complement-mediated lysis using MY9 synergistically kills CFU-L while sparing early normal hematopoietic progenitor cells, and thus may be a more effective way to purge BM than either alone.
Typing of MNSs blood group specific sequences in the human genome and characterization of a restriction fragment tightly linked to S-s- alleles
Authors: Huang CH , Guizzo ML , McCreary J , Leigh EM , Blumenfeld OO
Published: October 2019

Human erythrocyte membrane alpha and delta glycophorins (glycophorins A and B) carry the antigens for the M,N,S,s blood group system. Synthetic oligonucleotides spanning coding regions for M,N,S, and s epitopes were used to examine DNAs from 50 individuals selected at random and from individuals known to exhibit S(-)s(-)U- or S(-)s(-)U+ blood group phenotypes. We showed that M,N,S,s, blood group-specific sequences occur as multicopies in the human genome and reside within the alpha and delta glycophorin genes and also within the third glycophorin gene (glycophorin E gene). DNA typing with M- and N-epitope-specific probes showed distinct patterns that allowed correlation of the genotypes with the blood group phenotypes. The correlation using S- and s-specific probes was less definite owing to cross-hybridization. An Mspl restriction fragment length polymorphism (RFLP) residing in the E gene was detected in the black population. This RFLP is also carried by all individuals tested who exhibit the S(-)s(-)U- and S(-)s(-)U+ blood groups phenotypes, thereby serving as a useful marker for the S-s- alleles. The site of cleavage resulting in this RFLP was localized to the second intron of the E gene, and cleavage could occur through differential methylation of its two alleles.