bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myelodysplastic syndrome (MDS)‐associated inhibitory activity on haemopoietic progenitor cells
Authors: Ohmori Masami , Ohmori Seiichi , Ueda Yasunori , Tohyama Kaoru , Yoshida Yataro , Uchino Haruto 
Published: March 2008

SummaryWe studied MDS‐associated inhibitory activity, which inhibited colony formation in vitro of granulocyte‐macrophage progenitors (CFU‐GM). Macrophages obtained from MDS bone marrow mononuclear cells (BM‐MNC) when pretreated with granulocyte‐macrophage colony stimulating factor (GM‐CSF) suppressed the growth of normal CFU‐GM. These macrophages were designated as ‘MDS‐derived inhibitory macrophages’. Media conditioned by MDS‐derived inhibitory macrophages (MDS‐CM) also suppressed the growth of normal CFU‐GM. In the MDS‐CM, high levels of prostaglandin E2 (PGE2) and ferritin were found. However, MDS‐CM did not contain detectable levels of tumour necrosis factor (TNF) or gamma‐interferon (γ‐IFN). Antiserum against human placental ferritin and/or against PGE2 blocked the haemopoietic inhibitory activity to some extent.These results suggest that inhibitory macrophages may be responsible for the suppression of granulopoiesis in patients with MDS and that the suppression may be mediated by soluble factors including PGE2 and ferritin.
P47 phosphoprotein of blood platelets (pleckstrin) is a major target for phorbol ester‐induced protein phosphorylation in intact platelets, granulocytes, lymphocytes, monocytes and cultured leukaemic cells: absence of P47 in non‐haematopoietic cells
Authors: Gailani David , Fisher Thomas C. , Mills David C. B. , Macfarlane Donald E. 
Published: March 2008

SummaryAggregating agents including phorbol esters which activate protein kinase C induce the rapid phosphorylation of a Mr= 47 000 cytosolic protein in blood platelets (P47 or pleckstrin). This protein is well resolved by analytical 16‐BAC‐SDS two‐dimensional PAGE and was purified from platelets by preparative 16‐BAC‐SDS PAGE. Polyclonal antibodies were raised to the protein in mice and rabbits. These antisera detected a single protein with the migration of P47 on Western blots of platelet extracts, and the rabbit antisera immunoprecipitated 32P‐labelled P47 from platelet cytosol. The presence of P47 in other haematopoietic cells was determined by prelabelling them with 32P and observing increased 32P incorporation into the location of P47 on autoradiographs of 16‐BAC‐SDS analytical PAGE of cells exposed to phorbol ester. The identity of the phosphoprotein found in this location was further established by probing Western blots of SDS PAGE gels of cultured cell lines with the P47 antisera. P47 was detected in peripheral blood lymphocytes, monocytes and granulocytes (including the granulocytes of two unrelated patients with X‐linked chronic granulomatous disease). P47 was also found in HL‐60 promyelocytes (especially after differentiation with retinoic acid), U937 histiocytes, HEL leukaemia cells, and Raji ‘B’lymphoblasts. It was not detected in normal erythrocytes. K562 leukaemic cells, MOLT‐3 ‘T’lymphoblasts, or in wide range of non‐haematopoietic cell lines. We conclude that P47 is a major target for the action of phorbol ester induced phosphorylation in platelets, normal leucocytes and some haematopoietic cell lines. These cells have as their common feature the ability when stimulated to develop adhesive functions on their plasma membranes.
Re‐evaluation of the role of azathioprine in the treatment of adult chronic idiopathic thrombocytopenic purpura: a report on 53 cases
Authors: Quiquandon Isabelle , Fenaux Pierre , Caulier Marie Thérèse , Pagniez Dominique , Huart Jean Jacques , Bauters Francis 
Published: March 2008

SummaryWe treated 53 adults (mean age 54 years, range 17‐89; 37 females and 16 males) with chronic idiopathic thrombocytopenic purpura (ITP) by azathioprine. All patients had received at least one form of therapy (including splenectomy in 40 patients) and had less than 50 x 109/1 platelets. The duration of ITP before azathioprine was started ranged from 6 to 350 months (median 19). All patients initially received 150 mg/d of azathioprine. This was associated with a short initial course of prednisone (0.3–0.5 mg/kg d) in 10 of them, who were refractory to prednisone alone. 34 (64%) patients responded, including 24 (45%) complete remissions (CR), three (6%) partial remissions (PR) and seven (13%) minor responses (MR). Median time to achieve response was 4 months. 17 of the CR persisted after 7–182 months, 10 of them after discontinuation of azathioprine. Seven patients relapsed after 4–26 months, five of them after azathioprine was stopped or its dose was reduced. PR were short and the median duration of MR was 8 months. Overall, 21 patients (40%) had responses lasting 1 year or more and 17 (32%) lasting 2 years or more. Median duration of treatment was 18 months (range 3–84). Five patients died of bleeding while on treatment. No prognostic factors for response to azathioprine were found. Mild leucopenia was seen in seven patients and a moderate (x3) increase in transaminases in two patients. No opportunistic infections were seen and no malignancy has occurred since the onset of azathioprine. We conclude that azathioprine gives a relatively high incidence of durable responses and very limited side effects in chronic ITP, when splenectomy has failed or is contraindicated. This efficacy, in our experience, is superior to that obtained with other therapeutic approaches. As responses may be delayed, a course of azathioprine of 4 months is required before one can infer a failure to respond. In responding patients, however, the optimum duration of treatment remains to be established.
Increased platelet sensitivity to ristocetin is predicted by the binding characteristics of a GPIb/IX determinant
Authors: Miller Jonathan L. , Hustad Kent O. , Kupinski John M. , Lyle Vicki A. , Kunicki Thomas J. 
Published: March 2008

SummaryPlatelets from patients with platelet‐type von Willebrand disease (vWD) were used as immunogens for the production of murine monoclonal antibodies (MoAbs). One such MoAb, C‐34, inhibited ristocetin‐induced aggregation of patient or normal platelets. but not aggregation induced by other aggregating agents. As demonstrated by crossedimmunoelectrophoresis, C‐34 recognized an epitope within the GPIb/IX complex. In indirect immunofluorescence studies on fresh platelets, the ratio of any of four different anti‐GPIb MoAbs to one another was near unity (0.88‐1.14) both for normals and for patients. In contrast, the ratio of the binding of C‐34 to such a MoAb (AP‐1) was 0.31 ± 0.02 (x± SE) for normal platelets and significantly increased to 0.54 ± 0.01 for patient platelets (P < 0.001). In NP‐40 lysates of 3H‐labelled platelets, saturating concentrations of C‐34 produced much fainter bands than did AS‐2 or other anti‐GPIb MoAbs in the GPIb and GPIX regions. In contrast to the other anti‐GPIb MoAbs. C‐34 did not bind to the purified 125I‐Iabelled glycocalicin fragment of GPIb, to the glycocalicin derivative identified by crossed‐immunoelectrophoresis, or to the amino‐terminal ˜ 40 kDa portion of GPIbα cleaved from 3H‐labelled platelets by trypsin. C‐34 appears to be the first MoAb that is quantitatively informative in identifying the abnormal platelets in platelet‐type vWD. The observed differences between the patient and normal platelets may reflect an abnormality in the primary structure of the GPIb/ IX complex. Alternatively, patient platelets may have an abnormality of other structures near this region that impose less of a steric hindrance upon binding of antibody to the C‐34 epitope.
A genetic defect of erythrocyte band 4.2 protein associated with hereditary spherocytosis
Authors: Ideguchi Hiroshi , Nishimura Junji , Nawata Hajime , Hamasaki Naotaka 
Published: March 2008

SummaryWe report two patients with hereditary spherocytosis associated with band 4.2 protein deficiency from a Japanese family. The defect of band 4.2 protein was confirmed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) not only in freshly prepared white ghosts but also in washed whole erythrocytes. The finding was quite reproducible and was also recognized postsplenectomy. The interaction of ankyrin with band 3 in the patients’ghosts was stable both at low ionic strength and at acidic pH. Our results suggested that band 4.2 protein might not be essential for the structural stability of band 3‐ankyrin interaction. On the other hand, membrane protein phosphorylation studies revealed an increased phosphorylation of spectrin/ankyrin, band 3 and band 4.1 in the patients’erythrocytes as compared with normal cells. The finding might be related to a dysregulation of protein phosphorylation which could result in membrane instability in affected cells. Band 4.2 deficiency is an inherited disorder in association with hereditary haemolytic anaemias and seems to be relatively prevalent in the Japanese population.
CRM+ haemophilia A due to a missense mutation (372→Cys) at the internal heavy chain thrombin cleavage site
Authors: Pattinson J. K. , McVey J. H. , Boon M. , Ajani A. , Tuddenham E. G. D. 
Published: March 2008

SummaryWe have used the polymerase chain reaction (PCR) and differential oligonucleotide melting to screen for mutations in selected CpG dinucleotides in the factor VIII genes of haemophilia A patients. By this means we have identified and confirmed by sequencing a novel point mutation in codon 372 (CGC) of the factor VIII gene of a moderately severe CRM+ haemophiliac. The first C of this codon has been substituted by T resulting in the non‐conservative substitution of cysteine for arginine at an essential thrombin cleavage site in factor VIII. Analysis of three intragenic restriction fragment length polymorphisms was uninformative in the patient's family. However, DNA analysis for the specific mutation shows one sister and the patient's mother to be carriers, and the other sister to be normal. This DNA analysis confirmed the results of phenotype analysis by factor VIII coagulant to von Willebrand factor antigen ratios for the females at risk. The two carrier females had low factor VIII coagulant activity and excess VIII antigen as predicted but the non‐carrier sister also had anomalously high VIII antigen in her plasma. When feasible, mutation specific DNA analysis is able to resolve the difficulties posed by variable phenotype data and unknown level of mutation in sporadic haemophilia A.
An infrequent DNA polymorphism associated with severe von Willebrand's disease
Authors: Caekebeke‐Peerlinck Kathelijne M. J. , Bakker Egbert , Briet Ernest 
Published: March 2008

SummaryGenomic DNA of six unrelated Dutch patients with severe von Willebrand's disease (vWD) was submitted to restriction fragment length polymorphism analysis. We observed a strong association between a 36 kb allele detected by a partial complementary DNA probe (pvWF 1100) and the restriction enzyme XbaI with severe von Willebrand's disease. This 36 kb allele is rare (allele frequency of 7%) both in the general population and in patients with autosomal dominant types of von Willebrand's disease. Three of our six patients were found to be homozygous for this allele while two others were heterozygous. The association of this rare XbaI allele with severe vWD enables carrier detection and prenatal diagnosis in these families. The high frequency (67%) of the 36 kb allele observed in this patient group raises the possibility that a subgroup of patients with severe vWD has a genetic defect with a common origin.
Development of a highly sensitive assay, based on the polymerase chain reaction, for rare B‐lymphocyte clones in a polyclonal population
Authors: Brisco M. J. , Tan L. W. , Orsborn A. M. , Morley A. A. 
Published: March 2008

SummaryA method has been developed to use the polymerase chain reaction to amplify and sequence the chain determining region 3 (CDR3) of the human immunoglobulin heavy‐chain gene, and to use the sequence as a marker for rare neoplastic B lymphocytes. Consensus primers for the Variable and Joining regions of the gene were constructed and shown to enable efficient amplification, directed cloning, and sequencing of CDR3. Using leukaemic cell line PFMC as a test system, CDR3 was sequenced, specific primers synthesized, and PFMC DNA was detected down to a dilution of 1:1300 in DNA from normal lymphocytes. This strategy should be useful for monitoring therapy and detecting early disease relapse in B lymphoproliferative disease.
Stem cell recovery from cyclophosphamide‐induced myelosuppression requires the presence of CD4+ cells
Authors: Pantel Klaus , And Zora Djuric , Nakeff Alexander 
Published: March 2008

SummaryRecently, we have reviewed studies regarding the growth‐stimulating effect of CD4+ cells on haematopoietic cells in culture (Pantel & Nakeff, 1989a). In the present study we have tested the physiologic relevance of this interaction using a drug‐perturbed mouse model. The long‐term application of cyclophosphamide (CY, 30 mg/kg/d, five i.p. injections per week over 7 weeks) in B6D2F1 mice resulted in initial CY‐induced cytotoxicity to CFU‐S followed by the re‐establishment to pretreatment values of the femoral content of CFU‐S within 2–3 weeks of CY‐treatment. An examination of CY‐metabolism in these treated mice excluded a pharmacological explanation for the compensation of CY‐cytotoxicity. However, a three‐fold increase in the cycling fraction of CFU‐S (determined by in vivo hydroxyurea suicide) was observed concomitant with a two‐fold increase in the femoral content of L3T4+ cells (the murine equivalent to human CD4+ cells), as compared to the corresponding values in untreated mice. Ablating these L3T4+ cells in vivo by means of a cytotoxic monoclonal antibody (MoAb) to the L3T4 determinant resulted in a decrease in the cycling fraction of CFU‐S from 56.8% to essentially zero and a decrease in the femoral content of CFU‐S when comparing mice receiving either CY alone or CY plus MoAb, respectively. It would appear that the CY‐induced increase in the proliferative activity of CFU‐S requires the presence of L3T4+ cells. These data constitute the first in situ evidence for the physiologic relevance of immunocompetent L3T4+ cells as regulators involved in the recovery of stem cells from drug‐induced myelosuppression.
Exercise‐induced CD8 lymphocytosis: a phenomenon associated with large granular lymphocyte leukaemia
Authors: Mulligan S. P. , Wills E. J. , Young G. A. R. 
Published: March 2008

SummaryThis report describes a patient with a large granular lymphocyte leukaemia (CD8 + lymphoproliferative disease) and severe neutropenia (<0.5×109/l) in whom exercise resulted in a marked lymphocytosis, a phenomenon which has not previously been recorded. The lymphocyte count at rest was within normal limits (2.2 × 109/l), rose to a peak with strenuous exercise (38 x 109/l), then fell to the resting level within 15 min of cessation of exercise. The peripheral blood mononuclear cells showed the morphology of large granular lymphocytes (LGL) by light and electron microscopy both at rest (30%) and to a much greater extent during exercise (70%). Immunophenotyping of these lymphocytes during exercise demonstrated that the predominant cell was CD3+, CD8+, CD57+ (Leu7)/CD4‐, CD16‐, CD25‐. In the resting state, despite a total lymphocyte count within the normal range, surface marker studies indicated an excess of cells with the CD8+/CD57 + T cell phenotype (26%; cf. normal range ≦10%). Functional assays revealed a minimal increase in natural killer (NK) activity during exercise. T cell receptor β chain gene rearrangement was demonstrable in the peripheral blood at rest and during exercise. Although severe neutropenia was present, the growth of normal colony forming units, granulocyte‐macrophage (CFU‐GM) was not inhibited by patient lymphocytes and no anti‐neutrophil antibodies were demonstrated. Finally, hyposplenism has developed and the relationship of this to the LGL leukaemia is discussed. In summary, the findings demonstrated large granular lymphocyte leukaemia as the primary disorder for which the primary manifestation, apart from the neutropenia, was a marked exercise‐induced lymphocytosis.
A mutation adjacent to the beta cleavage site of factor IX (valine 182 to leucine) results in mild haemophilia Bm
Authors: Taylor S. A. M. , Liddell M. B. , Peake I. R. , Bloom A. L. , Lillicrap D. P. 
Published: March 2008

SummaryThe genetic basis of a mild form of haemophilia Bm has been investigated. The patient under investigation has a mild bleeding disorder and has never experienced spontaneous bleeds. Factor IX coagulant activity (FIX:C) was 0.15 units/ml and factor IX antigen (FIX:Ag) 1.32 units/ml. The prothrombin time performed with an ox brain thromboplastin was 65 s (normal plasma 31 s). Studies of the abnormal factor IX protein in this patient showed a normal molecular weight and normal calcium binding properties. Activation of the mutant factor IX with factor XIa showed normal proteolytic cleavage. DNA sequence from the eight factor IX exons and flanking introns was amplified from this patient using the polymerase chain reaction. The amplified material was subjected to direct chain termination nucleotide sequencing. The only nucleotide sequence alteration found was a G→C transversion at nucleotide 20.524, changing the amino acid encoded at residue 182 from valine to leucine. This residue is one amino acid removed from the beta cleavage site of factor IX. This residue is highly conserved in other vitamin K dependent serine proteases and we propose that its alteration in this patient is responsible for his mild haemophilic phenotype, and for the abnormal interaction of this factor IX protein with the extrinsic system of coagulation.
Clinical and laboratory evaluation of the treatment of von Willebrand's disease patients with heat‐treated factor VIII concentrate (BPL 8Y)
Authors: Pasi K. J. , Williams M. D. , Enayat M. S. , Hill F. G. H. 
Published: March 2008

SummaryAdequate rises of vWF:activity and satisfactory haemostasis have been obtained in six von Willebrand patients treated with heated 8Y factor VIII concentrate, despite multimeric analysis showing the concentrate to have an alteration in the proportions of the different vWF:Ag multimers including slight loss of the highest molecular weight multimers and an abnormal triplet. As heat‐treated concentrates reduce the risk of transmitting blood borne viruses 8Y concentrate should be considered as a possible first line treatment of vWD patients in the U.K. if they do not have mild forms of type I von Willebrand's disease which can be treated with desmopressin (DDAVP) infusions.
Two human monoclonal antiplatelet autoantibodies established from patients with chronic idiopathic thrombocytopenic purpura
Authors: Honda Shigenori , Tsubakio Tadahiro , Tomiyama Yoshiaki , Take Hironori , Furubayashi Takayasu , Mizutani Hajime , Kurata Yoshiyuki , Yonezawa Takeshi , Tarui Seiichiro 
Published: March 2008

SummaryTwo human hybridomas secreting antiplatelet autoantibodies were established by somatic cell fusion using splenocytes from two patients with chronic idiopathic thrombocytopenic purpura (ITP). These monoclonal antibodies, HT7F and HT8C, were of the IgM isotype and reacted with autologous and allogeneic platelets fixed with paraformaldehyde (PFA). They also bound to fresh platelets. An elution study showed that eluates from allogeneic platelets reacted with autologous platelets. These results indicated that HT7F and HT8C were autoantibodies recognizing a site on the platelet surface. Both monoclonal antibodies were able to induce complement activation in vitro. HT7F was demonstrated to bind to a platelet protein having a molecular mass of 105 kDa under both nonreducing and reducing conditions. No human hybridoma synthesizing antibody against 105 kDa platelet protein has been reported to date. These antibodies may play a role in the pathogenesis of thrombocytopenia in some ITP patients.
Studies of an oral iron chelator: 1,2 ‐dimethyl‐ 3 ‐hydroxy‐pyrid‐4‐one I. IRON EXCRETION IN RATS: DEVELOPMENT OF A NEW RAPID MICROWAVE METHOD FOR IRON ANALYSIS IN FAECES
Authors: Venkataram S. , Rahman Y. E. 
Published: March 2008

SummaryWe have developed a simple, rapid method for analysing faecal iron using a microwave oven for digestion followed by atomic absorption spectrometry. The chelating effect of l,2‐dimethyl‐3‐hydroxy‐pyrid‐4‐one (DMHP) has been tested in rats with experimental iron overloading and three routes of DHMP administration, oral, subcutaneous, and intraperitoneal, have been compared. Regardless of the route of administration, we have found that DMHP promotes iron excretion via the urine. We have not observed a difference in the amount of iron excreted in the faeces before and after DMHP administration by any route. The subcutaneous route of administration is the most effective in promoting iron excretion, followed by the intraperitoneal route. Although most convenient for clinical use, oral administration promotes the excretion of only a small fraction of that by the subcutaneous route.
Inhibition of lymphocyte IL2‐receptor expression by factor VIII concentrate: a possible cause of immunosuppression in haemophiliacs
Authors: Hay C. R. M. , McEvoy P. , Duggan‐Keen M. 
Published: March 2008

SummaryFactor VIII concentrate inhibits T‐cell function in vitro and in vivo. The mechanisms underlying this phenomenon were investigated. Factor VIII concentrate has a direct effect on lymphocytes, uninfluenced by haemophilic mono‐cyte dysfunction, since it inhibited lymphocyte transformation with phorbol myriscate acetate, a reaction unaffected by monocyte depletion. Inhibition of lymphocyte transformation by factor VIII concentrate is not corrected by the addition of exogenous IL2, suggesting that it does not inhibit lymphocyte function by suppression of IL2 secretion alone. Factor VIII concentrate causes profound inhibition of IL2‐receptor expression (CD25); with an 89% reduction in CD25‐positive CD4 cells and a 50% reduction in CD25‐antigen molecules per cell. CDS lymphocytes are similarly affected. Smaller reductions in CD71 and HLA‐DR expression are also observed. Down modulation of CD25‐antigen may explain the reduced IL2 secretion observed by others, and may be an important cause of immunodeficiency in HIV‐seronegative haemophiliacs.
Co‐expression of haemopoietic antigens on vascular endothelial cells: a detailed phenotypic analysis
Authors: Favaloro Emmanuel J. , Moraitis Nick , Bradstock Kenneth , Koutts Jerry 
Published: March 2008

SummaryOver 1000 monoclonal antibodies (MAB), previously characterized in terms of reactivity with various haemopoietic cells and including representatives from each of the currently known Clusters of Differentiation (CD), have now been evaluated by us for reactivity against human endothelial cells. In the current study, screening was performed on both fixed, and on non‐fixed, endothelial cells derived and cultured from umbilical cord veins. Results indicate that endothelial cells co‐express a wide variety of antigens that are otherwise characterized by expression on haemopoietic cells. The most intense and consistent degree of reactivity was seen using MAB to CD‐9, CD‐13, CD‐29, CD‐31, CD‐44, CD‐46, CD‐51, CD‐54 and CD‐55, although reactivity was also observed using MAB belonging to CD‐41, CD‐47, CD‐49, CD‐61 and CD‐71, in addition to a number of non‐clustered MAB.