bluuebunny/crossref_metadata_2025_split huggingface dataset:
Negative regulation of human megakaryocytopoiesis by human platelet factor 4 and beta thromboglobulin: comparative analysis in bone marrow cultures from normal individuals and patients with essential thrombocythaemia and immune thrombocytopenic purpura
Authors: Han Z. C. , Bellucci S. , Tenza D. , Caen J. P. 
Published: March 2008

SummaryThe effect of human platelet factor 4 (PF4) and beta‐thromboglobulin (BTG) on megakaryocyte colony formation in normal subjects as well as in essential thrombocythaemia (ET) and in immune thrombocytopenic purpura (ITP) was studied. Both PF4 and BTG were found to be capable of inhibiting the development of isolated megakaryo‐cytes and their colonies in normal marrow cultures in a dose‐dependent fashion. A significant 50% inhibition was seen at a PF4 or BTG concentration of 1–2·5 μg/ml, and complete inhibition in the range of 5–10 μg PF4 or BTG/ml. The two platelet proteins had similar effects on megakaryocyte development. A combination of PF4 and BTG resulted in an additive effect. Antibodies against PF4 or BTG could effectively neutralize the inhibitory effect of PF4 or BTG respectively. In ET and ITP, in vitro megakaryocyte development was also inhibited by PF4 and BTG in a similar way to that seen in normal subjects, suggesting that the responsiveness of megakaryocyte progenitors to PF4 and BTG is normal in these two disorders. PF4 and BTG did not affect the growth of colony forming units granulocyte‐macrophage (CFU‐GM) except at very high concentration (≥ 10 γg/ml) but they did inhibit erythroid colony formation by normal and ET burst forming units erythroid (BFU‐E). However, the inhibition of BFU‐E by PF4 and BTG was dose‐related, and a 50% inhibition required a PF4 or BTG dose ranging from 5 to 10 μg/ml. These results indicate that PF4 and BTG are involved in negative regulation of normal and pathologic megakaryocytopoiesis and that their inhibition acts predominantly on the megakaryocytic lineage.
Ras activation in myelodysplastic syndromes: clinical and molecular study of the chronic phase of the disease
Authors: Melani Cecilia , Haliassos Alexandre , Chomel Jean Claude , Miglino Maurizio , Ferraris Anna Maria , Gaetani Gian Franco , Kaplan Jean Claude , Kitzis Alain 
Published: March 2008

SummaryWe studied N‐ras and Ki‐ras point mutations respectively at codons 12–13 and 12 in 15 patients with myelodysplastic syndromes (MDS) using the polymerase chain reaction (PCR) method for DNA amplification, and slot blot hybridization to allele specific oligonucleotide (ASO) probes. We analysed peripheral blood and bone marrow samples collected at diagnosis and repeatedly during the chronic phase of the disease to define when the activation occurred and in which haemopoietic cell populations, in order to establish possible relationships between clinical and molecular features. In three cases the N‐ras oncogene was mutated at codon 12 in every cell population, both at diagnosis and throughout the chronic phase. Point mutations were not seen at the 12 codon of the Ki‐ras oncogene. In patients lacking activated ras oncogene at diagnosis, mutations were not discovered during the entire period of observation. Therefore in our cases disease progression and leukaemic transformation did not correlate with the presence of the activated N‐ras. Our data suggest that ras activation occurs early in the pathogenesis of MDS and involves a haemopoietic progenitor with multiple differentiative capacity, without however conferring an apparent proliferative advantage on its progeny.
A comparative evaluation of assays for markers of activated coagulation and/or fibrinolysis: thrombin–antithrombin complex, D‐dimer and fibrinogen/fibrin fragment E antigen
Authors: Boisclair M. D. , Lane D. A. , Wilde J. T. , Ireland H. , Preston F. E. , Ofosu F. A. 
Published: March 2008

SummaryMeasurements were made of levels of D‐dimer in plasma and serum, thrombin–antithrombin complex (TAT) in plasma and fibrinogen/fibrin fragment E antigen (FgE) in serum in a normal healthy control group and in patients with a range of disorders associated with hypercoagulability. Levels were determined in 31 normal healthy controls, 30 patients with disseminated intravascular coagulation (DIC), 21 patients with deep venous thrombosis (DVT), 27 patients with myocardial infarction (MI), 26 patients with acute leukaemia and 56 patients with liver disease. Considering all subjects, significant correlations were established between the results of all assays. Notably high correlations (r>0·9) were established between plasma and serum levels of D‐dimer, between plasma levels of D‐dimer and serum levels of FgE, and between serum levels of D‐dimer and FgE. All assays showed very high discrimination (sensitivity) between the normal control group and patients with DIC (97–100%), but there were marked differences between the assays in sensitivity for DVT and MI. In general, the FgE assay was more sensitive than the D‐dimer assay, whilst both the FgE and D‐dimer assays were more sensitive than the TAT assay. The same trends were apparent in the capability of the assays to discriminate between the normal control group and patients with acute leukaemia and liver disease: disorders with an unknown prevalence of activation of coagulation/fibrinolysis. Our results indicated that measurements of fibrinogen/fibrin degradation products (FDPs) in serum were almost unaffected by artefacts. The data further suggested that the broad‐spectrum FgE assay was better than the more specific D‐dimer assay in detecting clinical hypercoagulability. Our study showed that, in the clinical conditions examined, FDPs were more effective markers of hypercoagulability than TAT.
Previous donor pregnancy as a risk factor for acute graft‐versus‐host disease in patients with aplastic anaemia treated by allogeneic marrow transplantation
Authors: Flowers Mary E. D. , Pepe Margaret Sullivan , Longton Gary , Doney Kristine C. , Monroe Deborah , Witherspoon Robert P. , Sullivan Keith M. , Storb Rainer 
Published: March 2008

SummaryTo determine if previous donor pregnancies influence the development of acute graft‐versus‐host disease (GVHD) we evaluated data from 136 patients with aplastic anaemia greater than 15 years of age and given marrow grafts from HLA‐identical sibling donors. Of the 136 marrow donors, 30 were parous females (previous history of pregnancy), 30 were nulliparous females (no history of pregnancy or abortions), and 76 were males. The cumulative incidence of grade II‐IV GVHD was 57%, 21% and 46% for patients with parous, nulliparous and male donors, respectively. A multivariate analysis of the data confirmed that the risk of grade II‐IV acute GVHD was significantly increased among patients receiving marrow from parous females as compared to those from nulliparous females (relative risk = 2·5,P= 0·02). There was no statistically significant difference in the incidence of acute GVHD, however, between patients with parous donors and male donors (relative risk = 1·3,P= 0·26). Male patients given grafts from parous donors showed a higher incidence of acute GVHD (63%) than female patients (45%), though this difference was not statistically significant. The 5‐year probability of survival was 47% for patients with parous donors, 68% for patients with nulliparous donors and 70% for those with male donors. We confirm that prior donor pregnancy represents an important factor in selecting marrow donors or designing clinical protocols for GVHD prophylaxis.
Deficiency of glycosyl‐phosphatidylinositol anchored proteins on paroxysmal nocturnal haemoglobinuria (PNH) neutrophils and monocytes: heterogeneous deficiency of decay‐accelerating factor (DAF) and CD16 on PNH neutrophils
Authors: Kawakami Zenji , Ninomiya Haruhiko , Tomiyama Junji , Abe Tsukasa 
Published: March 2008

SummaryGlycosyl‐phosphatidylinositol (GPI) anchored membrane proteins have been reported to be deficient on affected paroxysmal nocturnal haemoglobinuria (PNH) blood cells. In the present study we investigated the deficiency of several GPI anchored membrane proteins on PNH neutrophils (PMN) and monocytes from 10 patients with PNH. Decay‐accelerating factor (DAF) and FcyR‐III (CD 16) on PMN, DAF and CD14 on monocytes, were investigated by two‐colour immunofluorocytometry. Neutrophil alkaline phosphatase activity was also assayed on PNH neutrophils. Normal human PMN were always shown phenotypically to be DAF+/CD16+. A DAF−/CD16− subpopulation of PMN was demonstrated in all the patients studied. In six out of the 10 patients, deficiencies of DAF and CD16 were found simultaneously on affected PNH PMN. The percentage of DAF− PMN showed a positive correlation with the neutrophil alkaline phosphatase (NAP) score. However, it should be noted that, in four out of the 10 patients with PNH, a DAF+/CD16− subpopulation of PMN was also clearly found. This may indicate that the deficiencies of DAF and CD16 on PNH PMN are heterogeneous. Normal human monocytes were demonstrated to be DAF+/CD14+, whereas PNH monocytes consisted of subpopulations of DAF+/CD14+ and DAF−/CD14−. In the same patients with PNH, the deficiencies of DAF on PMN and monocytes correlated well with each other. These results suggest that, at least in some patients with PNH, the mechanisms which induce the membrane defects of PNH blood cells are heterogeneous.
Prognostic importance of immunophenotyping in adults with acute myelocytic leukaemia: the significance of the stem‐cell glycoprotein CD34 (My 10)
Authors: Geller Robert B. , Zahurak Marianna , Hurwitz Craig A. , Burke Philip J. , Karp Judith E. , Piantadosi Steven , Civin Curt I. 
Published: March 2008

SummaryA series of 23 monoclonal antibodies reactive with normal lymphoid and myeloid cells at various stages of differentiation were used to characterize 96 adult patients with acute myelocytic leukaemia (AML), concentrating on the possible role the expression of these antigens may have in predicting response to intensive chemotherapy. Only the expression of CD34 (P= 0·008) and HLA‐DR (P= 0·035) was significant in predicting response to therapy; patients with leukaemic cells expressing CD34 (My10) had a complete remission (CR) rate of 59% compared to 87% for those with blasts not expressing the antigen. In a multivariate analysis predicting for CR, the expression of CD34, the disease category (de novoAML versus secondary AML [SAML] or a history of antecedent haematological disorder [AHD]), and WBC were significant covariates. Adjusting for disease category and WBC, patients with CD34‐positive AML were one‐third as likely to enter CR as with those with disease not expressing the antigen (P= 0·066). Comparison of clinical characteristics between the 58 patients whose leukaemia expressed CD34 and the 33 which were CD34‐negative found that patients with CD34‐positive AML had a higher incidence of SAML and AHD, a lower WBC at diagnosis, and a more frequent incidence of chromosomal abnormalities involving chromosomes 5 and/or 7. Twenty‐eight of these patients also had immunophenotyping performed at relapse. Patients who presented with CD34‐positive AML, and entered remission, and then relapsed all recurred with CD34‐positive leukaemia; there was no case of CD34‐positive AML at diagnosis relapsing with CD34‐negative disease. In addition, there were patients presenting with CD34‐negative AML and then relapsing with CD34‐positive AML. These results suggest that intensive cytoreductive therapy is ineffective against CD34‐positive AML. Patients who present with CD34‐positive AML may require different therapeutic approaches to completely eradicate their disease.
Pretransfused patients with severe aplastic anaemia exhibit high numbers of cytotoxic T lymphocyte precursors probably directed at non‐HLA antigens
Authors: Kaminski E. R. , Hows J. M. , Goldman J. M. , Batchelor J. R. 
Published: March 2008

SummaryPatients with severe aplastic anaemia (SAA) have a relatively high risk of graft rejection after transplantation of bone marrow from HLA‐identical siblings compared with patients transplanted for leukaemia. This is presumed to be due to pretransplant blood transfusions which sensitize the recipient's immune system to non‐HLA antigens expressed on donor marrow cells. To test this hypothesis, we estimated in the peripheral blood of 18 SAA patients, the frequencies of alloreactive cytotoxic T lymphocyte precursors (CTL‐p) directed against mononuclear cells from syngeneic twins, HLA‐identical siblings or HLA‐matched unrelated individuals. The results were compared with the frequencies of CTL‐p in 13 healthy subjects or leukaemia patients who had not been transfused. Pretransfused patients with SAA had significantly higher frequencies of CTL‐p directed against HLA‐identical siblings (P= 0·002), and against HLA‐matched unrelated individuals (P= 0·004), than did untransfused individuals. In contrast, the frequency of CTL‐p in two pretransfused patients against syngeneic mononuclear cells was very low. We propose that the increased numbers of CTL‐p in the blood of pretransfused SAA patients are directed against non‐HLA antigens on target cells and may be the result of prior blood transfusion.
Immunocytochemical detection of ferritin in human bone marrow and peripheral blood cells using monoclonal antibodies specific for the H and L subunit
Authors: Invernizzi Rosangela , Cazzola Mario , De Fazio Pasqualina , Rosti Vittorio , Ruggeri Giuseppina , Arosio Paolo 
Published: March 2008

SummaryWe have used the monoclonal antibodies 2A4 (specific for the H subunit of human ferritin) and LO3 (specific for the L subunit) for immunocytochemical detection of ferritin in bone marrow and peripheral blood cells from normal subjects and patients with various haematological disorders. Formalin‐fixed slides were stained by the immunoalkaline phosphatase procedure (APAAP). In normal subjects, ferritin could be found only in bone marrow smears and appeared to be largely confined to erythroid precursors and reticuloendothelial cells. The more immature erythroid precursors contained higher concentrations of cellular ferritin. Although evaluation could be only semiquantitative, erythroblast ferritin appeared to be more reactive with the monoclonal 2A4 (15 ± 7% positive erythroblasts) than with the monoclonal LO3 (6 ± 5% positive erythroblasts), indicating that H‐type ferritin was predominant, particularly in proerythroblasts and basophilic erythroblasts. By contrast, the ferritin present in reticuloendothelial cells appeared to be predominantly of L‐type. Patients with iron deficiency showed low levels of positive erythroblast, whereas the reverse was true in patients with transfusional iron overload. Intense positivity for reticuloendothelial cell ferritin was found in patients with anaemia of chronic disease. In myelodysplastic syndromes and acute myeloid leukaemia (AML), ferritin positivity was generally very strong at any stage of erythroblast development, particularly with the monoclonal antibody 2A4. Perls‐positive perinuclear granules of ring sideroblasts were not stained, confirming that mitochondrial iron deposition is not in the form of ferritin. In AML and myelodysplastic syndromes with excess of blasts, ferritin could be detected also in immature myeloid cells. These data indicate that: (a) in normal conditions ferritin is mainly expressed in red cell precursors and reticuloendothelial cells, and this is in keeping with the peculiar role of these cells in iron metabolism; (b) abnormal cell ferritin contents can be observed in both iron overload and malignancy.
Effect of recombinant human erythropoietin on anticancer drug‐induced anaemia
Authors: Matsumoto Tomoko , Endoh Kouichi , Kamisango Keiichi , Akamatsu Ken‐ichi , Koizumi Kinya , Higuchi Masato , Imai Nobuo , Mitsui Hiroki , Kawaguchi Tsutomu 
Published: March 2008

Summary. Anaemia was induced in rats with fluorouracil (5‐FU) or cisplatin (CDDP) and the mechanisms of anaemia induction were analysed. Furthermore, the therapeutic effects of recombinant human erythropoietin (rHu Epo) on these anticancer drug‐induced anaemias were investigated.In 5‐FU‐induced anaemia, marked serum erythropoietin (Epo) elevation was observed in inverse correlation to blood Hb concentration and Hb concentration rapidly recovered to normal levels. On the other hand, in CDDP‐induced anaemia, serum Epo elevation was modest and the lowered Hb concentration persisted longer. Treatment with rHu Epo significantly improved both anticancer drug‐induced anaemias but rHu Epo was more effective on CDDP‐induced anaemia. These results suggest that rHu Epo might be useful for the therapy of anaemia associated with anticancer chemotherapy.
The platelet and plasma pools of plasminogen activator inhibitor (PAI‐1) vary independently in disease
Authors: Simpson A. John , Booth Nuala A. , Moore Norma R. , Bennett Bruce 
Published: March 2008

Summary. The relative importance and behaviour of plasma and platelet plasminogen activator inhibitor (PAI‐1) in disease has not hitherto been examined. In this study the concentration of PAI‐1 in the plasma and platelets of patients with a variety of disorders was examined using a specific ELISA and a functional assay. Mean plasma PAI‐1 was elevated in groups of patients with diabetes mellitus, hypertension, alcoholic cirrhosis, angina and myocardial infarction. Plasma PAI‐1 was raised in the post‐operative phase and the PAI‐1 released after surgery was not derived from platelets. In all groups PAI‐1 in the platelet pool reflected the platelet count, except in type II diabetes mellitus and chronic renal failure, where a reduced quantity of PAI‐1 antigen per platelet was found. In severe chronic renal failure, abnormal platelets and diminished platelet PAI‐1 may contribute to the haemorrhagic tendency sometimes seen in this disorder.Plasma PAI‐1 represents a larger proportion of total circulating PAI‐1 in disease than it does in healthy individuals; PAI‐1 per platelet is abnormal only in a minority of disorders. Plasma and platelet pools of PAI‐1 vary independently in disease and both merit consideration in evaluating the importance, if any, of PAI‐1 in thrombosis or haemorrhage.
The role of fibronectin in platelet aggregation
Authors: Thurlow P. J. , Kenneally D. A. , Connellan J. M. 
Published: March 2008

Summary. A monoclonal antibody (anti‐Fn2) was prepared which was reactive with both plasma fibronectin and fibronectin located within the platelet alpha granule. Immunoblotting analysis, on thermolysin digestion fragments of fibronectin, identified two immunoreactive fragments of Mr 145 kDa and 155 kDa which are known to contain a cell and DNA binding region. Anti‐Fn2 was found to inhibit binding of fibronectin to platelets and DNA. Functional platelet studies, measuring platelet aggregation and 14C‐serotonin release in washed platelet systems, demonstrated the ability of anti‐Fn2 to totally inhibit low dose thrombin and low‐dose collagen induced platelet aggregation and serotonin release. Anti‐Fn2 partially inhibited platelet aggregation induced by ADP (10 μM) and arachidonic acid, but had no effect on platelet aggregation induced by high‐dose thrombin or by the calcium ionophore A23187.These studies indicate that fibronectin participates in platelet aggregation and release induced by a range of agonists and suggest that it has a more important involvement in platelet function than previously described.
Evaluation of a new UVB source for irradiation of platelet concentrates
Authors: van Prooijen H. C. , van Marwijk Kooy M. , van Weelden H. , Aarts‐Riemens M. I. , Borghuis L. , Akkerman J. W. N. 
Published: March 2008

Summary. The application of ultraviolet B (UVB) radiation has been proposed as a new technology to decrease immunogenicity of leucocytes in platelet transfusions. UV radiation also induces platelet aggregation, which occurs most effectively at wavelengths between 240 and 280 nm and falls off sharply above 300 nm. In order to minimize the effects of UV energy on the platelets we evaluated in this study the expected benefit of a new narrow‐band UVB source, emitting a narrow peak around 312 nm. Exposure of platelet or lymphocyte suspensions to this source induced in the platelets both aggregation and functional defects at a dose of 12 J/cm2 and in the lymphocytes inhibition of in vitro function at a dose of 2 J/cm2. A conventional UVB source, emitting a broad spectrum between 280 and 340 nm, was more deleterious for the cells and induced similar defects in the platelets at a dose of 6 J/cm2 and inhibition of lymphocyte function at a dose of 1 J/cm2. These data indicate no benefit for the new UVB source, since the ratio of the doses to induce platelet defects and inhibition of lymphocyte function is identical for each of the two sources.Absorption of UV energy by plasma and the plastic material of platelet containers is another criterium for selection of UV sources. In view of the better transmission characteristics of long wavelength UV energy we propose that there is a preference for the new narrow‐band UVB source.
The utility of a HindIII polymorphism of factor VIII examined by rapid DNA analysis
Authors: Graham John B. , Kunkel Glenna R. , Fowlkes Dana M. , Lord Susan T. 
Published: March 2008

Summary. A previously described HindIII restriction fragment length polymorphism (RFLP) of factor VIII (FVIII) has its polymorphic site in the unsequenced nineteenth intron. We have located the polymorphic site, as well as an invariant site, by amplifying and sequencing IVS 19 using the polymerase chain reaction (PCR). The oligonucleotide primers were synthesized from known FVIII sequence on either side of the 19–20 splice junction. The amplified product was cloned into a plasmid and sequenced by the dideoxy chain termination method. The polymorphic HindIII site was 103 bp and the invariant site 184 bp from the 3’end of the nineteenth exon.The frequency of the polymorphism was determined in 457 subjects (643 chromosomes) of seven ethnic groups on whom frequency of the BclI RFLP of IVS 18 was also assessed. The HindIII site is highly polymorphic in all groups, ∼ 0.25:0.7 5, the expected heterozygosity averaging 37.6%. and the observed number of heterozygotes did not differ significantly from expectation. The (+):(‐) allelic ratio is similar in all groups, except African‐Americans in whom it is reversed. Strong allelic association (linkage disequilibrium) is present between the HindIII polymorphism of IVS 19 and the BclI polymorphism of IVS 18.
Lack of useful clinical predictors of response to splenectomy in patients with chronic idiopathic thrombocytopenic purpura
Authors: Juliá A. , Araguás C. , Rosselloa J. , Bueno J. , Domenech P. , Olona M. , Guardia R. , Petit J. , Flores A. 
Published: March 2008

SummaryWe set out to identify clinical or analytical variables that might predict the response to splenectomy in patients with chronic idiopathic thrombocytopenic purpura (ITP).We retrospectively examined 138 mostly adult patients with chronic ITP, treated with splenectomy. Information was compiled from five Public Health Hospitals from a questionnaire and chart review. Sixty‐one potentially prognostic variables were analysed by univariate and multivariate statistical methods. After multivariate analysis, age (relative risk=1.02; CI 1–1.03) and a severity of the bleeding diathesis (relative risk = 1.6; CI 1.13–2.22) were independent prognostic factors for a sustained response to splenectomy.An independent analysis of the postsplenectomy counts showed that an early (days 1–3) thrombocyte count exceeding 156 ± 109/1 cells increases the likelihood of a permanent unmaintained response.Our data indicate that the response to splenectomy in patients with chronic ITP cannot be adequately predicted on the basis of pre‐splenectomy clinical or analytical variables.