bluuebunny/crossref_metadata_2025_split huggingface dataset:
IIB von Willebrand's disease: pathogenetic and therapeutic studies
Authors: Kyrle P. A. , Niessner H. , Dent J. , Panzer S. , Brenner B. , Zimmerman T. S. , Lechner K. 
Published: March 2008

Summary. Infusion of 1‐deamino‐(8‐D‐arginine)‐vasopressin (DDAVP) into patients with IIB von Willebrand's disease (vWD) has been reported to induce thrombocytopenia. In some families with this disorder thrombocytopenia is present even in the resting state. We have investigated the basis of this chronic thrombocytopenia in one such patient by performing platelet recovery and survival studies. Increased platelet consumption was suggested by a decrease in platelet recovery (40.5%, normal 45%) and mean platelet survival (112 h, normal range 144–224 h). In addition, we have administered test infusions of DDAVP and observed the effect on bleeding time and platelet count. DDAVP caused a decrease in the median platelet count from 86 × 109/1 (range 30–221) to 60 × 109/1 (range 5‐144), the individual decline in the nine subjects ranging from 12% to 84% compared to the pretreatment values. Formation of platelet aggregates was observed in all patients following DDAVP. The bleeding time was prolonged before DDAVP in all patients and lengthened further in two after the infusion. However, partial correction of the bleeding time was seen in three and normalization in one patient following DDAVP infusion.Two IIB vWD patients were treated with virus‐inactivated cryoprecipitate (Ristofact®). Infusion of cryoprecipitate was followed by rapid appearance of all but the largest vWF multimers in plasma and did not affect the platelet count. The bleeding time was normalized in one patient but remained prolonged in the other.In conclusion, in IIB vWD patients virus‐inactivated cryoprecipitate is the treatment of choice in the case of bleeding. Infusion of DDAVP might be effective in a subset of IIB vWD patients that has yet to be characterized.
The in vivo ageing of red cell enzymes: direct evidence of biphasic decay from polycythaemic rabbits with reticulocytosis
Authors: Zimran Ari , Torem Shlomo , Beutler Ernest 
Published: March 2008

Summary. The rate at which the activities of red cell enzymes decay during maturation of the reticulocyte and ageing of the erythrocyte is poorly understood. It has recently been suggested that loss of enzyme activity may be rapid during reticulocyte maturation and occur slowly thereafter. We have now devised a rabbit model in which reticulocytosis is combined with transfusional polycythaemia. This makes it possible to follow the enzymatic activity of a cohort of reticulocytes without the interfering effect of newly formed cells.In this model the reticulocyte count of the experimental animals falls from about 60% to subnormal levels within 4 d. Red cell hexokinase activity declined rapidly with more than half of the activity being lost within 7 d, little change occurring thereafter. Glucose‐6‐phosphate dehydrogenase activity declined more gradually, but also followed a biphasic course. The fall of pyrimidine 5’nucleotidase activity was the slowest of the three age‐dependent enzymes studied. This is consistent with our observations in children with transient erythroblastopenia of childhood, in which this enzyme, alone of the age‐dependent enzymes, was found to be decreased in a senescent red cell population. In contrast to the three age‐dependent enzymes studied, the activity of lactate dehydrogenase remained unchanged during the course of the experiment.These studies provide direct verification of the suggestion that the decline of red cell enzyme activities may be biphasic. They show, moreover, that enzyme decay is not only rapid in reticulocytes, but also in young erythrocytes.
Human liquid bone marrow culture in serum‐free medium
Authors: Drouet Xavier , Douay Luc , Giarratana Marie‐Catherine , Baillou Claude , Gorin Norbert‐Claude , Salmon Charles , Najman Albert 
Published: March 2008

SummaryProlonged in vitro maintenance of human bone marrow progenitor cells was achieved using a serum‐free (SF) liquid culture system. Culture medium was based on Iscove's medium supplemented with bovine serum albumin, human transferrin, bovine insulin, soybean lecithin, cholesterol, hydrocortisone and alpha‐thioglycerol. Under these standardized culture conditions, CFU‐GM were maintained for up to 4 weeks, as is the case when using conventional serum‐dependent medium. Erythropoiesis exhibited a slower decline than that found using serum containing medium. Development of normal haematopoiesis was effective in spite of poor stromal cell development—a confluent adherent layer as classically described in serum conditions was never achieved. Our newly defined system provides a reliable technique for studying human haematopoietic stem cell proliferation and differentiation in vitro; it allows for rational utilization of currently available purified recombinant growth factors. It may be a promising tool in the clinical use of cultured haematopoietic stem cells.
Regulatory abnormalities in the marrow of patients with myelodysplastic syndromes
Authors: Merchav Shoshana , Nagler Arnon , Fleischer‐Kurtz Gila , Tatarsky Ilana 
Published: March 2008

SummaryRegulation of haemopoiesis in the marrow of patients with myelodysplastic syndromes (MDS) was evaluated by assaying (1) the production of haemopoietic regulators acting upon multipotent and committed progenitors by MDS marrow cells, and (2) the responsiveness of MDS marrow progenitors to stimulation with granulocyte colony‐stimulating factor (G‐CSF). The levels of multipotent progenitor cell colony‐stimulating activity (CFU‐GEMMCSA) in 7 d bone marrow‐conditioned medium (BMCM) from MDS patients were markedly reduced as compared to controls. MDS BMCM also exhibited reduced levels of burst‐promoting activity (BPA) for primitive erythroid (BFU‐E) progenitors. Both CFU‐GEMMCSA and BPA detected in BMCM were completely neutralized by antibodies directed against interleukin‐3. MDS BMCM exhibited markedly reduced levels of murine‐active CSA. This activity was partially neutralized by anti‐CSF‐1 antibodies. Levels of regulators in BMCM of refractory anaemia (RA), sideroblastic anaemia, RA with excess blasts, and chronic myelomonocytic leukaemia were virtually the same. CFU‐GEMM and BFU‐E growth in MDS marrow (n= 9) was markedly reduced. A 5‐fold saturating dose of G‐CSF induced an approximately 2‐fold increase in CFU‐GEMM in four of eight MDS and a 1.5‐fold increase of BFU‐E in five of nine MDS, but not in control (n= 5) marrow cell cultures. Impaired haemopoiesis in MDS marrow may be related to abnormalities both in regulator production by marrow accessory cells and in regulator responsiveness of multipotent and committed progenitors.
Co‐incident N and K ras gene mutations in a case of AML, restricted to differing cell lineages
Authors: Hiorns Lynne R. , Cotter Finbarr E. , Young Bryan D. 
Published: March 2008

SummaryPeripheral blood from a patient with acute myeloid leukaemia (AML) of M5 FAB classification, was shown to have mutations to both the N and K ras genes. Leucophoresed blood was separated on a discontinuous Percoll density gradient to provide fractions enriched for different cell lineages. DNA extracted from these fractions was amplified using the polymerase chain reaction (PCR) technique, and hybridized with oligonucleotide probes specific for the single base mutations previously demonstrated. The N‐ras mutation was shown to be restricted to the blast and monocytic cell fractions, concordant with the FAB subtype of M5. The K‐ras mutation, however, was present in all fractions, suggesting it had occurred in a multi‐potential stem cell representing an earlier stage in the generation of the leukaemia, or possibly an incidental background phenomenon.
IL‐2 and myelopoiesis: IL‐2 induces blast cell proliferation in some cases of acute myeloid leukaemia
Authors: Carron J. A. , Cawley J. C. 
Published: March 2008

SummaryInterleukin‐2 (IL‐2) stimulated H‐thymidine incorporation in the blasts of six of 21 cases of acute myeloid leukaemia (AML). An IL‐2 induced increase in cell numbers was directly demonstrated in the two patients studied in this way, and T‐cell contamination was rigorously excluded. The IL‐2‐induced proliferation was usually less marked than that caused by granulocyte‐macrophage colony stimulating factor (GM‐CSF), and IL‐2 moderately enhanced GM‐CSF‐induced stimulation in five of the six patients; in the sixth, IL‐2 and GM‐CSF were strongly synergistic. IL‐2‐induced proliferation was observed only in AML with a monocytic component (M4/M5), but not all M4/M5 leukaemias responded to IL‐2. There was no correlation between expression of the light‐chain of the IL‐2 receptor and IL‐2‐induced stimulation.It is suggested that IL‐2 is involved at a restricted stage of early myelopoiesis, perhaps when cells are becoming committed to the monocytic lineage: and that IL‐2 is a growth factor for early myeloid cells in a proportion of cases of AML.
True histiocytic lymphoma: histopathologic, immunophenotypic and genotypic analysis
Authors: Hanson Curtis A. , Jaszcz Waclaw , Kersey John H. , Astorga Magdalena G. , Peterson Bruce A. , Gajl‐Peczalska Kazimiera J. , Frizzera Glauco 
Published: March 2008

SummaryFive cases of true histiocytic lymphoma (THL) were analysed by immunophenotyping and immunoglobulin/T‐cell receptor genotyping. These cases showed striking morphologic diversity but a strong degree of immunophenotypic homogeneity. The malignant cells reacted with multiple histiocytic markers including CD11c (Ki‐M1, LeuM5), CD14, CD68 (Ki‐M6) and Ki‐M8; anti‐HLA‐DR and non‐specific esterase staining was also found in all cases. The malignant cells did not express monoclonal immunoglobulin and did not react with the B‐ or T‐cell monoclonal antibodies used except for those known to be cytoplasmically expressed in monocytes/histiocytes, such as CD4 and CD19; B‐ and T‐cell staining was otherwise limited to background small lymphocytes. By genotypic analysis, three cases showed rearrangements: one with Tβ, one with Tβ and immunoglobulin heavy chain (JH) and one with both JH and light chain: the remaining two cases retained their immunoglobulin and T‐cell receptor genes in germline configuration. The results not only suggest that certain subsets of the histiocyte/reticulum cell system may be capable of rearranging immunoglobulin or Tβ genes while simultaneously expressing multiple histiocytic surface antigens but also demonstrate the necessity of using multiple histiocytic‐specific monoclonal antibodies and cytochemical staining in diagnosing THL. Gene rearrangement studies must be interpreted in conjunction with immunophenotyping and morphology in the determination of cell lineage.
Effect of exchange transfusion of reticulocytes on in vitro and in vivo intestinal iron (Fe3+) absorption in mice
Authors: Raja K. B. , Simpson R. J. , Peters T. J. 
Published: March 2008

SummaryThe effect of acute changes in erythron demands and in plasma‐iron turnover (PIT) on the in vitro and in vivo absorption of 59Fe3+ was studied in the mouse. Hypoxic exposure for 20 h (a time at which intestinal iron absorption is markedly stimulated) induced reticulocytosis with a marked elevation in PIT. More prolonged exposure (3 d) further enhanced the plasma‐iron clearance, even though the absorption of 59Fe was not further increased.Recipient mice, exchange transfused with whole blood from phenylhydrazine‐treated animals, had a marked reticulocytosis and elevated PIT. However, in vivo studies exhibited only a small enhancement in intestinal 59Fe absorption. In vitro studies, in contrast, showed no changes in the kinetic parameters for duodenal Fe3+ uptake in similarly‐transfused mice. Blood cells, rather than plasma, were responsible for the enhanced in vivo absorption in the transfused animals.These data indicate that acute changes in body iron demands and in PIT have only a small effect on iron absorption via a process independent of the adaptive increase in carrier‐mediated uptake following chronic (3 d) hypoxia. This regulatory process, however, is inadequate to explain the adaptive changes seen during acute (20 h) hypoxic exposure.
The development of spatial distributions of CFU‐S and in‐vitro CFC in femora of mice of different ages
Authors: Mason T. M. , Lord B. I. , Hendry J. H. 
Published: March 2008

SummaryThe radial distributions of spleen colony forming units (CFU‐S) and in‐vitro colony forming cells (in‐vitro‐CFC) were measured in the diaphyseal marrow cavity of femora removed from 3‐, 5‐ and 11‐week‐old mice. The distributions observed in 11‐week‐old mice confirm earlier findings that the highest concentrations of CFU‐S exist near bone surfaces whereas the concentration of in‐vitro‐CFC increases to a peak value approximately 300 μm from the femoral axis with a low value at the bone surface. The gradients of the distributions in all three age groups are very similar suggesting that spatial organization in marrow is established by 3 weeks at the latest and, as the marrow cavities grow, so the distributions extend into the new space following their respective gradients. The peak of CFU‐S concentration at the bone surfaces in all age groups coincides with increased rates of DNA synthesis and a low self‐renewal capacity. Conversely. CFU‐S nearer the centre of the cavity maintain a low turnover but have a high self‐renewal capacity. Measurements made on 1‐week‐old mice show that the marrow contains a lower average concentration of CFU‐S in the femoral cavity compared to older mice. However, these CFU‐S have both a high rate of turnover and a high self‐renewal capacity. It appears that these better quality CFU‐S remain in a central location while the rest of the population ages and expands in association with growing bone regions.
Slow evolution of chronic myeloid leukaemia relapsing after BMT with T‐cell depleted donor marrow
Authors: Hughes T. P. , Economou K. , Mackinnon S. , Vlitos M. , Arthur C. K. , Guo A. P. , Rassool F. , Apperley J. F. , Hows J. , Goldman J. M. 
Published: March 2008

SummaryThirty‐three patients with Philadelphia positive (Ph +) chronic myeloid leukaemia (CML) treated in chronic phase by bone marrow transplantation (BMT) with T‐cell depleted HLA‐identical sibling marrow were evaluable for relapse at a median follow up of 41 months (range 16‐59 months). Twenty‐six (78%) had Ph+ marrow metaphases demonstrated at some time post BMT. The subsequent pattern of disease was variable. In 15 of these cases haematological relapse occurred within 24 months of BMT. Four patients proceeded to haematological relapse more slowly. Seven patients had only cytogenetic evidence of relapse. Of the 19 patients with haematological relapse, five received second transplants and two survive; 13 of the other 14 survive in chronic phase at median times from allografting and from recognition of haematological relapse of 41 months (range 25‐59 months) and 18 months (range 5‐36 months) respectively. For these 13 patients disease progression after relapse seems to be relatively indolent. In the four patients we could study, blood lymphocytes were almost all of donor origin. We suggest that even in patients with cytogenetic or haematological evidence of relapse after T‐cell depleted BMT, leukaemic cell proliferation may still be restrained to some extent by a graft‐versus‐leukaemia effect mediated by donor‐derived lymphoid cells.
Cytotoxic potential of anti‐CD7 immunotoxin (WT1‐ricin A) to purge ex vivo malignant T cells in bone marrow
Authors: Preijers F. W. M. B. , Witte T. De , Wessels J. M. C. , Meyerink J. P. P. , Haanen C. , Capel P. J. A. 
Published: March 2008

Summary With the perspective of bone marrow purging in autologous transplantation, we investigated the cytotoxicity of the anti‐T cell immunotoxin (IT) WT1‐ricin A (anti‐CD7) to malignant T cells obtained from patients with T cell acute lymphoblastic leukaemia or lymphoma. The cytotoxic efficacy of IT was based on the extent of protein synthesis inhibition. Cytotoxicity of IT to malignant T cells showed a dependency on antigen density comparable to the T cell lines GH1, CEM, Jurkat, HSB‐2 and HPB‐ALL and was enhanced considerably in the presence of 6 mm ammonium chloride. The ultimate proof of cell kill can only be obtained from clonogenic assays: however, culturing of malignant T cells was not feasible. Therefore these assays were performed with the cell line CEM that expresses comparable amounts of CD7 antigen as malignant T cells of most patients. More than 6‐logs of CEM appeared to be eliminated after incubation with 10‐8m WT1‐ricin A.Immunotoxins are only effective after entering the target cell. The pattern of internalization of the IT was determined by means of 125I‐WT1. After internalization the CD7 antigen was re‐expressed on the cell membrane. This enables a long incubation period resulting in an increased elimination of malignant T cells. Even after 16 h the IT was still accumulated intracellularly. This pattern of continuous uptake of IT was reflected in a gradually increasing cytotoxicity with incubation time. Effective bone marrow purging can be carried out without adverse effects on progenitor cells with 10‐8m WT1‐ricin A. At that concentration the antibody binding capacity was saturated.We showed that the protein synthesis inhibition in malignant T cells by WT1‐ricin A is comparable to the inhibition in T cell lines and that high amounts of CEM cells can be killed. These data suggest that cell lines can be used to test the efficacy of IT to malignant T cells. WT1‐ricin A appears to be very potent for the purging of autologous bone marrow from patients with T cell malignancies.
Complement sensitivity of erythroblasts and erythropoietic precursors in paroxysmal nocturnal haemoglobinuria (PNH)
Authors: Shichishima Tsutomu , Terasawa Takashi , Uchida Tatsumi , Kariyone Shigeo 
Published: March 2008

Summary To clarify the regulation of erythropoiesis of complement (C')‐sensitive erythrocytes (E) during erythroid cell maturation and differentiation in paroxysmal nocturnal haemoglobinuria (PNH), the C'sensitivity of (1) erythroblasts from erythropoietic bursts and (2) erythropoietic precursors was examined in seven patients with PNH. For the former, a modified complement lysis sensitivity (CLS) test using the trypan blue dye exclusion method was employed. For the latter, an erythropoietic cell culture following the CLS or sucrose haemolysis (SH) test for mononuclear cells was used. Linear relationships were found between the concentrations of C'and proportions of C'‐mediated haemolysed erythroblasts in both PNH and normal erythropoietic bursts. In addition, PNH erythroblasts showed hypersensitivity to C'; in the C'dilution for 50% lysis was 12·5±8·1 ml in PNH patients and 42·3±4·5 ml in normal controls. There was also a significant correlation (r=0·919; P<0·01) between the proportions of PNH‐III E and haemolysed erythroblasts. Significant hypersensitivity of mature erythroid progenitors (CFU‐E) to C'was found in both the SH (P<0·01 or P<0·05) and CLS (r=‐0·712: P<0·001) tests in PNH patients. However, no hypersensitivity to C'was observed at the primitive erythroid progenitors (BFU‐E) level in either the PNH patients or the normal controls.These findings suggest that in PNH the property of C'sensitivity appears during differentiation and maturation from BFU‐E to CFU‐E and that the proportions of PNH‐III E are already programmed at the level of erythroblasts.
Immunoglobulin light chains in common acute lymphoblastic leukaemia
Authors: Markey Geraldine M. , Alexander H. D. , Nolan R. L. , Morris T. C. M. , Robertson J. H. 
Published: March 2008

SummaryA single immunoglobulin light chain λ was identified in the blast cells of two out of 12 patients with common acute lymphoblastic leukaemia (C‐ALL) using the alkaline phosphatase/anti‐alkaline phosphatase (APAAP) technique. Inhibition at the cell surface proved that the reaction was a genuine anti‐λ reaction. Immunoglobulin μ chain was not identified in these patients. Results of immunoglobulin typing in 103 patients with B chronic lymphocytic leukaemia (B‐CLL) are cited to show the increased sensitivity of the APAAP technique as compared to the indirect immunoperoxidase technique for cellular immunoglobulin identification.
PL2‐49, a monoclonal antibody against glycoprotein IIb which is a platelet activator
Authors: Morel M.‐C. , Lecompte T. , Champeix P. , Favier R. , Potevin F. , Samama M. , Salmon C. , Kaplan C. 
Published: March 2008

SummaryPL2‐49 is a murine monoclonal IgG1 antibody obtained after immunization of Balb/c mice with EDTA washed platelets. Binding could be detected on Zwa(+) as well as Zwa(—) platelets, but not on type I Glanzmann's thrombasthenia platelets using an ELISA screening test. Immunoprecipitation studies showed that PL2‐49 bound to glycoprotein IIb when the glycoprotein IIb/IIIa complex dissociation was performed after the monoclonal antibody binding. Experiments with a human alloantibody against Zwa antigen were run in parallel to control the complex dissociation. Ascitic fluid, as well as the purified antibody, induced activation and aggregation of washed platelets and ATP release. PL2‐49‐induced aggregation did not require exogenous fibrinogen and was inhibited, partially, in the presence of aspirin, apyrase, isosorbide dinitrate. Raising intra‐platelet cyclic AMP with a stable PGI2 analogue, iloprost, and/or a phosphodiesterase inhibitor, RA 233, suppressed the responses to PL2‐49. F(ab')2 fragments did not induce aggregation of normal platelets but inhibited the response to the whole immunoglobulin. Finally PL2‐49 was shown to induce aequorin‐detected elevations in intraplatelet Ca++ levels. Thus PL2‐49 seems to differ from monoclonal antibodies so far described, since it binds to glycoprotein IIb in a complex‐dependent manner at least under our experimental conditions for immunoprecipitation studies, and it induces platelet Ca++ mobilization and platelet aggregation after a lag‐time. These reactions depend both on Fab and Fc domains of the antibody and require neither complement nor exogenous fibrinogen.
A prospective comparison of four techniques for measuring platelet‐associated IgG
Authors: Kelton John G. , Murphy William G. , Lucarelli Anne , Garvey‐Williams Judy , Santos Aurelio , Meyer Ralph , Powers Peter 
Published: March 2008

SummaryWe describe a prospective study comparing four different assays for PAIgG. Platelets from patients with a variety of thrombocytopenic disorders were collected into ACD, washed, and the PAIgG then measured using three assays for surface PAIgG. These included: (a) a direct binding assay using 125I‐monoclonal anti‐IgG (MoAb); (b) a direct binding assay using 125I‐staphylococcal protein A (SPA); and (c) a two‐stage assay. PAIgG also was measured using an assay for ‘total’ PAIgG following platelet lysis. The mean ± SD number of molecules of IgG per platelet on washed platelets from 29 healthy, non‐thrombocytopenic controls was: 86 ± 80 (125I‐MoAb); 94 ± 96 (125I‐SPA); 3520 ± 1890 (two‐stage surface assay); and 10 850 ± 3720 (total PAIgG). A total of 62 different patients with idiopathic thrombocytopenic purpura or thrombocytopenia complicating systematic lupus erythematosus, and 73 different patients with‘non‐immune’ thrombocytopenia, were tested using each of the four assays. These ‘non‐immune’ thrombocytopenic patients included patients with carcinoma, septicaemia, pre‐eclampsia, chronic leukaemia, thrombotic thrombocytopenic purpura, haemolytic uraemic syndrome, acute leukaemia and myelodysplasia. All four essays gave similar results for both the immune and non‐immune thrombocytopenic patients. The sensitivity of the assays for the most severely thrombocytopenic patients with immune thrombocytopenia was: MoAb 60%; SPA 88%; two‐stage 82%; and‘total’ PAIgG 88%. The specificity of the four assays in the non‐immune thrombocytopenic patients was 57%‘total’ PAIgG; 63% two‐stage surface; 25% SPA; 38% MoAb. There was no quantitative cut‐off point that could be used to segregate the non‐immune thrombocytopenic patients from the immune thrombocytopenic patients. These results indicate that all of these assays share a similar high sensitivity but low specificity for ITP.