bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the partition of transferrin‐donated iron in rabbit reticulocytes
Authors: Egyed A.
Published: March 2008

Summary. Reticulocytes with high cytosolic non‐haem radioiron content were prepared by adding metabolic inhibitors. The cells were then reincubated without the inhibitors for various periods of time. Cytosol was prepared from the labelled cells and fractionated on a Sephadex G‐100 column on which four main non‐haem radioiron containing peaks could be distinguished. During reincubation the 59Fe content of these cytosol fractions changed in different ways.

The high molecular weight fraction showed little metabolic activity, indicating that this fraction is not utilized for haem synthesis when iron is in excess in the cytosol. The second non‐haem radioiron containing peak eluted with the haemoglobin moiety. This non‐haem iron binding substance proved to be rather stable: 1 mM EDTA could not remove a significant amount of iron from it. During reincubation its radiorion content decreased almost linearly with time. Two further peaks eluted in the low molecular weight region. Their kinetics during reincubation suggest that these peaks represent those non‐haem iron components of the cytosol which can reversibly move from the cytosol into the stroma compartment.
Thromboplastin as a marker for monocyte differentiation
Authors: Lyberg T. , Ivhed I. , Prydz H. , Nilsson K.
Published: March 2008

Summary. The thromboplastin synthesis of the human monocytoid cell line U‐937 and its two subclones designated U‐937‐3 and U‐937‐4 has been studied. U‐937‐4 seems by several functional criteria to represent a more advanced stage of monocyte differentiation than the original U‐937. U‐937‐3 appears to be arrested at an even more immature stage than the original population. The basal thromboplastin activity was higher in U‐937‐4 than in U‐937‐3 or U‐937 cells (7·0±l‐9 (SEM), 1 0±0 2 and l 6±0 6 units/mg protein, respectively) although not as high as in human normal monocytes (14 1 ±2 4). The thromboplastic expression of the two clones was maximai when cells were in logarithmic growth. Both clones responded with a weak to moderate thromboplastin synthesis upon addition of stimulants like phytohaemagglutinin (PHA), immune complexes or endotoxin. Thromboplastin production was also potentiated in the presence of lymphocytes. The supporting effect of lymphocytes was strong in the case of U‐937‐3 as well as in U‐937 cells, but less pronounced in U‐937‐4 cells as it also is in human monocytes. The thromboplastin response after PHA stimulation was more rapid in U‐937‐4 cells (maximai after 4–8 h) than in U‐937 or U‐937‐3 cells (12–16 h). Human monocytes also responds quickly to PHA (maximally 4 h). TotAl phospholipid content and the relative distribution of individual phospholipids were essentially similar in U‐937‐3, U‐937‐4 and U‐937. With regard to thromboplastin production, U‐937‐4 cells seem to be more monocyte‐like than the more immature cells U‐937‐3 and U‐937. It is concluded that thromboplastin seems to be a useful marker for monocyte differentiation.
Studies with human erythrocyte pyruvate kinase (PK): effects of modification of sulfhydryl groups
Authors: Valentine William N. , Paglia Donald E.
Published: March 2008

Summary. Cysteinyl residues of red cell pyruvate kinase (PK; ATP: pyruvate phosphotransferase, EC 2.7.1.40) were modified with methylmethanethiosulfonate (MMTS), p‐nitrophenoxycarbonyl methyl disulfide (NPCMD), and sodium tetrathionate (NaTT). At pH>iddot;0, K0·5s phosphoenol‐pyruvate (PEP) was markedly increased. Fructose‐1, 6‐diphosphate (FDP) increased affinity for PEP, but K0·5s (PEP) remained elevated and hyperbolic kinetics were not achieved. Inhibition by negative effectors ATP and alanine was not reversed by PEP and FDP concentrations far greater than those abolishing inhibition of unmodified enzyme. At pH < 7·0, PEP affinity was reduced, and FDP markedly increased Vmax and diminished K0·5s (PEP). MMTS greatly impaired the thermostability of PK. Acid pH alone and the simultaneous presence of Mg++, K+ and PEP prior to MMTS treatment protected against the effects on PEP kinetics, but did not alter the induction of thermolability. No MMTS effect on the FDP binding site, on ADP kinetics or on the relative effectiveness of GDP, UDP or CDP cofactors was demonstrated. The MMTS‐induced alterations closely resembled those observed with certain PK mutants associated with haemolytic anaemia.
Effects of valinomycin, A23187 and repetitive sickling on irreversible sickle cell formation
Authors: Westerman Maxwell P. , Allan David
Published: March 2008

Summary. The formation of irreversibly sickled red cells has been studied by inducing cell shrinkage, ion loss, Ca2+ accumulation and membrane loss either singly or in combination. Valinomycin, A23187 + Ca2+ or hypertonic saline caused shrinkage of the cells with retention of the sickled form after reoxygenation. The cells which had retained the sickle shape after treatment with the ionophores and reoxygenation remained sickled after exposure to hypotonic media. These cells were also osmotically insensitive. Retention of the sickled form was not dependent upon membrane loss as induced by repeated sickle‐unsickle cycles or by A23187 + Ca2+ treatment although repetitive sickling did give rise to shorter, stubbier spicules. Sickled red cells, either the endogenous irreversibly sickled cells or the sickled cells induced by deoxygenation, did not lose membrane by vesicle or spicule loss as normal cells or oxygenated sickle red cells do. Cell water loss without cell membrane loss appears to be an important factor in the irreversible sickling of red cells.
Antibodies against platelet membrane glycoproteins
Authors: Jenkins C. S. P. , Clemetson K. J. , Ali‐Briggs Elizabeth F.
Published: March 2008

Summary. Glycocalicin has been proposed as the common platelet receptor for both ristocetin‐human VIIIR:WF and thrombin‐induced platelet aggregation. Platelets which have lost glycocalicin do not respond to either ristocetin‐human VIIIR:WF or bovine VIIIR:WF. Using antibodies to the platelet membrane glycoproteins la and lb, lib and Ilia, and glycocalicin we show that the Fab'fragments of anti‐glycoproteins la and lb and anti‐glycocalicin IgG totally inhibited bovine VIIIR:WF‐induced platelet aggregation, while those from anti‐glycoproteins lib and Ilia IgG were without effect. Thrombin‐induced platelet aggregation was strongly inhibited by the Fab'fragments of anti‐glycoproteins la and lb IgG and anti‐glycocalicin IgG, indicating that these glycoproteins play a major role in thrombin‐platelet interaction. Fab'fragments of antiglycoproteins lib and Ilia IgG inhibited thrombin‐induced platelet aggregation to a lesser extent implying that these glycoproteins are also somehow involved in the platelet response to thrombin perhaps as fibrinogen receptors.

The data presented here give further support to the proposal that ristocetin‐human VIIIR:WF and bovine VIIIR:WF share a common receptor on the platelet surface and indicate that this structure plays an important role in thrombin‐induced platelet responses.
Colchicine ultrasensitivity of lymphocytes in chronic lymphocytic leukaemia
Authors: Wetherley‐Mein G. , Thomson A. E. R. , O'Connor T. W. E. , Peel W. E. , Singh A. K.
Published: March 2008

Summary. It has been previously reported that, in comparison with normal lymphocytes, the lymphocytes in chronic lymphocytic leukaemia (CLL) are ultrasensitive in culture to the cytocidal action of colchicine. In this report the results of 240 colchicine studies in 87 patients with CLL are presented and analysed in terms of the diagnostic, clinical and haematological significance of colchicine ultrasensitivity (CUS) in CLL.

All patients with CLL showed very significantly increased CUS of lymphocytes. The CUS did not vary with clinical and haematological status or time and only very rarely with treatment. There was no correlation between % CUS and subsequent course or survival. The results in CLL and in other forms of lymphocytosis and in non‐Hodgkin's lymphoma are compared.

It is concluded that the test is of considerable diagnostic value, particularly in identifying low‐count and treated CLL and in the exclusion of non‐CLL lymphocytosis. It appears to have no prognostic value but may have future application in monitoring treatment which selectively eliminates the abnormal cell population.
Fibrinogen Manchester: identification of an abnormal fibrinopeptide A with a C‐terminal arginine→histidine substitution
Authors: Southan C. , Kehl M. , Henschen A. , Lane D. A.
Published: March 2008

Summary. Purified samples of fibrinogen Manchester, a congenital dysfibrinogenaemia with impaired fibrinopeptide A (FPA) release, were digested with thrombin. Amino acid sequencing of the fibrin showed that FPA had been completely released. High performance liquid chromatographic (HPLC) analysis of the clot supernatant showed the presence of a new peptide eluting ahead of the normal FPA. The amino acid composition and sequence of the new peptide established its identity as a variant of FPA containing histidine in position 16 instead of the usual arginine. The chromatograms from both siblings with the defect demonstrated that they were heterozygous for this clotting defect.
Defective spectrin dimer–dimer association in a family with transfusion dependent homozygous hereditary elliptocytosis
Authors: Evans J. P. M. , Baines A. J. , Hann I. M. , Al‐Hakim I. , Knowles S. M. , Hoffbrand A. V.
Published: March 2008

Summary. Red cell membrane proteins have been examined in a family in which three children have severe transfusion‐dependent homozygous hereditary elliptocytosis. The membranes in all three show a considerable excess of spectrin dimers over tetramers in spectrin extracts. The red cell membranes of their parents with heterozygous hereditary elliptocytosis show a lesser but significant increase in spectrin dimers. Some of the family members also have an α‐globin gene deletion and haemoglobin D trait.

The present results are the first demonstration of a defect of spectrin dimer–dimer association in homozygous elliptocytosis and provide strong support for the concept that this defect is the primary cause of the red cell abnormality in at least some families of hereditary elliptocytosis.
Acquired von Willebrand's disease: demonstration of a circulating inhibitor to the factor VIII complex in four cases
Authors: Sampson Barbara M. , Greaves M. , Malia R. G. , Preston F. E.
Published: March 2008

Summary. We have studied four patients suffering from acquired von Willebrand's disease. All patients had a severe bleeding diathesis with recurrent life‐threatening haemorrhages. Three of the patients had a monoclonal gammopathy and one of these developed multiple myeloma. In three patients tested, a plasma inhibitor to ristocetin cofactor activity was detected. In each case this was localized to the IgG fraction of plasma. In addition, VIII:C activity was found to be associated with the IgG fraction of patients’ plasma and altered mobility of VIII: C was detected on Laurell immunoelectrophoresis. Furthermore, plasma from all four patients and the IgG fraction therefrom resulted in a dissociation of normal VIII:C into two components separable by gel‐filtration on Sepharose 6B. Finally, the circulating half‐life of the three factor VIII activities was found to be markedly reduced in the patients with acquired von Willebrand's disease.

We conclude that in the patients studied the coagulation defect was related to the presence of a circulating inhibitor to the factor VIII complex and that this inhibitor was associated with the IgG fraction of plasma.
Determination of the amino acid substitution in human prothrombin type 3 (157 Glu Lys) and the localization of a third thrombin cleavage site
Authors: Board P. G. , Shaw D. C.
Published: March 2008

Summary. Prothrombin was purified from normal blood donors and individuals heterozygous for prothrombin type 3. Comparison of the purified prothrombin preparations by tryptic peptide mapping, amino acid analysis and automated sequencing after thrombin digestion, has indicated that prothrombin type 3 results from the substitution of a lysine residue for glutatmic acid at position 157. This substitution can result from a single base change in the structural gene and explains the relatively slow electrophoretic mobility of prothrombin type 3 at alkaline pH. An additional thrombin cleavage site in profragment 1 has been identified at arginine 54 by automated sequence analysis of thrombin digests of prothrombin.
Characterization of the erythropoietic precursors (BFU‐E) in a patient with juvenile chronic myelogenous leukaemia by the analysis of Gγ and Aγ globin chains
Authors: Terasawa Takashi , Ito Toshiharu , Matsuda Sachiko , Suzuki Hitoshi , Kasai Shiro
Published: March 2008

Summary. In order to investigate the pathogenesis of juvenile chronic myelogenous leukaemia (J‐CML) we examined the biosynthetic rates of Gγ and Aγ globin chains in the erythropoietic bursts from the bone marrow of a patient with J‐CML. Globin chains were labelled with 14C‐labelled amino acids, separated by isoelectric focusing and quantitated by fluorography. The synthesis of γ‐chains in the erythropoietic bursts comprised 89·0% of the total non‐α‐chains. The Gγ: Aγ ratio was 0·67, which is within the ratios obtained in newborns. Furthermore, individual erythropoietic bursts contained varying ratios of both γ and β chains and all revealed more Gγ than Aγ chain synthesis. The relative proportions of Gγ and total γ chain biosynthesis in 62 separate erythropoietic bursts were 0·69·0·06 and 0·86·0·06, respectively. Cumulative frequency distributions of individual bursts differing in the ratios of γ/(γ+β) and Gγ/(Gγ+Aγ) approached normal frequency distributions. These results suggest that the levels of Hb F in J‐CML are controlled by qualitative changes in a single population of erythropoietic precursors, in which normal switching of the Gγ:Aγ ratio has not occurred, rather than by the abnormal proliferation of an F‐cell clone.
Radiosensitivity in Fanconi anaemia: application to the conditioning regimen for bone marrow transplantation
Authors: Gluckman E. , Devergie A. , Dutreix J.
Published: March 2008

Summary. Fanconi anaemia, an autosomal recessive constitutional aplastic anaemia, seems to be related to a DNA repair mechanism defect. Bone marrow transplantation is the only treatment which can cure these patients. Previous attempts at BMT have shown an increased sensitivity to Cyclophosphamide used for the conditioning. Such a sensitivity has also been observed in vitro when Fanconi anaemia cells were incubated with alkylating agents. We have tested the in vivo radiosensitivity and cell repair after skin contact radiotherapy to calculate the irradiation dose which could be tolerated by FA patients. Eight patients have been tested and the results confirmed the suspected increased radiosensitivity in the majority of patients. Following these results, four patients were conditioned with low dose Cyclophosphamide (20 mg/kg) associated with 5 Grays thoraco‐abdominal irradiation. All had a take and no major complication of the conditioning regimen. All are alive in good condition from day 51 to day 330 after transplant. Oesophagitis was one major unexpected complication. This study confirms the possibility of curing FA patients with BMT when the conditioning regimen is modified according to the pathophysiology of the disease.
Effect of DDAVP on plasma level of factor XII
Authors: Nenci G. G. , Berrettini M. , Cunto M. De , Agnelli G.
Published: March 2008

Summary. The effect of DDAVP on blood coagulation factors was investigated after its intravenous infusion into normal subjects. A marked increase in factor XII was observed in addition to the expected rise of factor VIII coagulant activity (VIII:C), factor VIII related antigen (VIII:Ag) and plasminogen activator. DDAVP also produced a concomitant but less pronounced rise of factor VII, but there was no change in factors V, IX, X and XI.
Haemopoietic stimulators and inhibitors in aplastic anaemia serum
Authors: Nissen Catherine , Moser Yolanda , Speck Bruno , Bendy Johanna
Published: March 2008

Summary. Normal serum and serum from four patients with severe aplastic anaemia was fractionated by Sephadex G‐150 gel filtration. Fractions were tested for direct haemopoietic activity on colony forming cells in methylcellulose cultures, and for their indirect influence on haemopoiesis via CSA‐ and BPA‐producing cells. All aplastic anaemia sera contained abnormal inhibitors and stimulators. An inhibitor acting on both haemopoietic and factor producing cells, eluting with the IgM fraction was found in all, variable inhibitors of lower molecular weight in single patients. Stimulatory activity of 10000–50000 MW acting on factor producing cells, but not on colony forming cells directly, was found in all, a variable stimulator eluting with the very high MW fraction in single patients.

In two patients who achieved complete autologous bone marrow remission after treatment with high dose immunosuppression, Sephadex fractions of serum before treatment and remission serum were simultaneously tested on autologous bone marrow in remission. Inhibitors were detected before treatment and disappeared in remission, stimulators were not detectable before treatment but became strong in remission. It is concluded that the effect of aplastic anaemia serum on haemopoiesis in culture is determined by the balance of inhibitors and stimulators on both haemopoietic and CSA/BPA producing cells.
Detoxification of xenobiotics by glutathione S‐transferases in erythrocytes: the transport of the conjugate of glutathione and 1‐chloro‐2,4‐dinitrobenzene
Authors: Awasthi Yogesh C. , Misra Gopal , Rassin David K. , Srivastava Satish K.
Published: March 2008

Summary. The incubation of human erythrocytes with 1‐chloro‐2,4‐dinitrobenzene (CDNB) results in almost quantitative conjugation of glutathione (GSH) to form S‐(2,4‐dinitrophenyl) glutathione. The reaction is catalysed by erythrocyte glutathione S‐transferase. During the present studies we have identified the conjugate in the incubation medium of CDNB‐treated erythrocytes, indicating that the conjugate of GSH and CDNB is transported out by the erythrocytes. Quantitation of the conjugate in the incubation medium by amino acid analysis and thin layer chromatography indicates that the erythrocytes transport the conjugate at an approximate rate of 140 nmol/h/ml erythrocytes. The transport of the conjugate is inhibited by sodium fluoride. Exhaustion of ATP from the erythrocytes results in a significant decrease in the rate of transport which is restored with the regeneration of ATP by incubating the erythrocytes with adenine and inosine. This indicates that the transport of conjugate is an energy dependent process.
Serum beta2microglobulin and survival duration in multiple myeloma: a simple reliable marker for staging.
Authors: Bataille Regis , Durie Brian G. M. , Grenierj Jean
Published: March 2008

Summary.Previous reports have shown serum beta2microglobulin (SB2M) to be a reliable marker for evaluation of presenting tumour mass, response to chemotherapy and prognosis of patients with multiple myeloma (MM). In the current study, SB2M was evaluated and correlated by bivariate and multivariate regression analyses with the main presenting clinical features, response to chemotherapy and survival duration of 115 untreated myeloma patients.

In the bivariate analysis, there was a clear correlation between SB2M and myeloma stage (P= 0·002). Other interesting correlations were between SB2M and creatinine values (P< 0·001), SB2M and the likelihood of having lambda subtype (P< 0·001), high SB2M and high uric acid (P< 0·036), high SB2M and a low haemoglobin (P< 0·001). In the multivariate regression analyses, SB2M alone completely substituted for the effect of initial staging and gave a very reliable fit for survival prediction. Particularly noteworthy was the dramatic difference in survival duration observed between patients with a high pre‐treatment SB2M (> 6 μg/ml) and those with low SB2M: 26 months versus 52 months (P< 0·0001).

We conclude that SB2M is the major determinant of survival in MM and can be used alone for effective pretreatment stratification of myeloma patients.
A phenomenological difference between membrane skeletal protein complexes isolated from normal and hereditary spherocytosis erythrocytes
Authors: Pinder Jennifer C. , Dhermy D. , Baines A. J. , Lux S. E. , Gratzer W. B.
Published: March 2008

Summary. Membrane skeletons may be obtained from human erythrocytes by extraction with non‐ionic detergent. When treated under defined conditions with a cAMP‐independent kinase preparation from normal membranes, a suspension of these membrane skeletons sets to a gelatinous mass. Membrane skeletons from the cells of hereditary spherocytosis patients fail to show this response. Those from subjects with some other haemolytic anaemias do not share the abnormality. The gelation process could be shown also to occur with normal membrane skeletons, extracted at high ionic strength, and containing essentially only the structural protein constituents, spectrin, actin, 4·1 and 4·9. It also occurred rapidly when a column‐purified kinase preparation was used, so that no significant amounts of contaminating proteins were introduced. Added spectrin, 4·1 or actin in moderate amounts did not induce gelation in the presence of ATP. Cytochalasin E did not perturb the gelation process. Gelation required ATP as well as kinase, and did not occur when the non‐hydrolysable analogue, AMP‐PNP, was used instead. Gelation was accompanied by phosphorylation of the spectrin alone, and is thus evidently a consequence of the modification of its properties by this means. Inhibition of phosphorylation by added adenosine retarded gelation. It may be inferred that phosphorylation of spectrin generates new, probably weak, non‐covalent interactions between cytoskeletal constituents that cause association of the isolated cytoskeletons. A semi‐quantitative method of observing the gelation process, based on the time of incubation before the membrane skeleton suspension ceases to flow under gravity a t a low shear. is described.
Susceptibility to invasion by Plasmodium falciparum of some human erythrocytes carrying rare blood group antigens
Authors: Cartron J. P. , Prou O. , Luilier M. , Soulier J. P.
Published: March 2008

Summary. Tn and Cad erythrocytes which carry unusual carbohydrate moieties attached to glycophorin A and B, the main red cell membrane sialoglycoproteins, resist invasion by the malarial parasite Plasmodium falciparum. Tn red cells are defective in sialic acid and galactose whereas Cad erythrocytes are characterized by a normal sialic acid content but the presence of an additional N‐acetylgalactosamine residue attached to each sialotetrasaccharide chain O‐glycosidically linked to glycophorin A and B. Homozygous MgMg red cells, which are defective in the cluster of three sialotetrasaccharide chains located at positions 2, 3 and 4 of glycophorin A, are normally invaded. Erythrocytes typed McM carry a glycophorin A molecule intermediate between those from M and N (amino acid substitution at position 1 or 5) but are, like control MN red cells, susceptible to invasion. These results suggest that the primary requirement for entry of P. falciparum merozoites into human red cells is the recognition of a carbohydrate structure present on glycophorin A or B which includes sialic acid and galactose, but is not necessarily clustered at the N‐terminal end of the molecule.
A new congenital defect of platelet secretion: impaired responsiveness of the platelets to cytoplasmic free calcium
Authors: Hardisty R. M. , Machin S. J. , Nokes T. J. C. , Rink T. J. , Smith Sharon W.
Published: March 2008

Summary. A 16‐year‐old boy with a bleeding disorder since infancy has a long bleeding time, normal platelet count and morphology and normal plasma factor‐VIII activities. His platelets undergo normal shape change and primary aggregation in response to ADP but show defective 5‐hydroxytryptamine (5‐HT) secretion and aggregation in response to adrenaline, sodium arachidonate, U44069, PAF‐acether, A23187 and low concentrations of collagen. Thrombin and higher concentrations of collagen produce a normal response. Secretion of β‐thromboglobulin and platelet factor 4 parallels that of 5‐HT. Thromboxane B2 is produced normally in response to exogenous arachidonate and to stimulation by thrombin, collagen and A23187 in all concentrations tested. The patient's endoperoxides and thromboxane A2 aggregate aspirin‐treated platelets, though his platelets are themselves unresponsive. Cyclic AMP is present at normal concentration in the patient's unstimulated platelet‐rich plasma, and PGI2 inhibits platelet aggregation by ADP and thrombin in a normal dose‐related manner. Platelet ultrastructure, 5‐HT uptake and content of adenine nucleotides, platelet factor 4 and β‐thromboglobulin are all within normal limits.

When the patient's platelets were loaded with the fluorescent dye quin 2, which serves as an indicator of cytoplasmic free calcium ions, their responses to thrombin, whether in the presence or virtual absence of extracellular Ca2+, were entirely normal in respect of free calcium ions, secretion, shape‐change and aggregation. In response to ionomycin, however, a normal increase in free calcium ions was accompanied by normal shape‐change but virtually no aggregation or 5‐HT secretion. The platelet calmodulin content was normal. These findings show that the defect in this patient's platelets is of utilization of cytoplasmic Caz+ for secretion and aggregation, rather than of Ca2+ uptake or mobilization of Ca2+ from intracellular storage sites. It is suggested that the most likely site of the defect is the phosphorylation of one of the proteins concerned in the secretory mechanism.
Rhesus immunization in male volunteers: changes in lymphocyte functions following secondary immunizations in anti‐D responders and non‐responders
Authors: Barclay G. R. , Greiss M. A. M. , McCann Moira C. , Urbaniak S. J.
Published: March 2008

Summary. After secondary immunizations of rhesus(D)‐negative male volunteers with Rh(D)‐positive red cells, changes were found in the in vitro transformation and antibody‐dependent cell‐mediated cytotoxicity (ADCC) capacities of the volunteers’ lymphocytes. Responders, who produced anti‐D, showed marked depressions of ADCC which were not found in non‐responders. Responders and non‐responders in general showed similar changes in lymphocyte transformation. The relationships between altered lymphocyte functions following immunization, immunoregulatory activity and responsiveness to the Rh(D) antigen are discussed.
Activation of coagulation and fibrinolytic systems following stroke
Authors: Lane D. A. , Wolff S. , Ireland H. , Gawel M. , Foadi M.
Published: March 2008

Summary. When the human blood coagulation and fibrinolytic systems are activated thrombin cleaves fibrinopeptide A (FPA) and plasmin cleaves Bβ1‐42 from fibrin(ogen). Elevated plasma concentrations of FPA and Bβ1‐42 are evidence for enhanced thrombin and plasmin activities in plasma. We have determined the plasma concentrations of FPA and Bβ1‐42 in patients who have had thrombotic stroke. Patients who were studied immediately following stroke were found to have greatly elevated plasma FPA and Bβ1‐42 levels, but these decreased to the concentrations found in an apparently healthy age‐matched control group 1 month after the infarct. In contrast, the plasma concentrations of the platelet release product β‐thromboglobulin (βTG) were slightly, but significantly, elevated immediately following the stroke and these did not alter with time after the infarct. It is concluded that following thrombotic stroke increased thrombin and plasmin activities are to be found in plasma. These increased protease activities are probably not directly associated with an increased in vivo platelet release reaction and may be useful in deciding which patients are at risk of reinfarction or stroke progression.
Alpha globin gene analysis in a Sardinian family with interacting alpha and beta thalassaemia genes
Authors: Melis M. A. , Galanello R. , Cao A.
Published: March 2008

Summary. This paper reports the results of alpha globin gene analysis in a Sardinian family with interacting α and β thalassaemia genes. The propositus, who was identified in a newborn survey as he had 26·0% Hb Bart's and 74·0% Hb F, successively developed the clinical and haematological picture of a transfusion‐dependent thalassaemia major. According to the haemoglobin pattern, restriction endonuclease analysis of the DNA from this patient showed the deletion of three of the four α‐globin structural genes. Thus β°‐thalassaemia homozygotes with the deletion of three α‐structural genes seem to have a severe clinical phenotype similar to that of patients with a full complement of four a‐globin structural genes.
T‐cell acute lymphoblastic leukaemia with late developing Philadelphia chromosome
Authors: Miller Barbara A. , Reid Michael M. , Nell Marilyn , Lipton Jeffrey M. , Sallan Stephen E. , Nathan David G. , Tantravahi Ramana
Published: March 2008

Summary A case of childhood T‐cell acute lymphoblastic leukaemia (ALL) is presented in which the only chromosome abnormality at diagnosis was a deletion of part of the short arm of one chromosome 9 (9p−). Cytogenetic studies at relapse showed, in addition to 9p−, a partial deletion of the long arm of one chromosome 6 (6q−) and the Philadelphia chromosome (Ph1) produced as a result of the classical translocation t(9q+;22q−). All metaphases from haemopoietic colonies grown from a cryopreserved specimen of this patient's marrow at relapse were normal, in contrast to haemopoietic colonies cultured from patients with chronic myelogenous leukaemia (CML) which contained the Ph1. A hypothesis which incorporates T‐cell ALL with late development of the Ph1 into the overall family of Ph1 positive diseases is suggested.
Late onset pyridoxine‐responsive sideroblastic anaemia after allogeneic bone marrow transplantation
Authors: Nicholls M. D. , Atkinson K. , Biggs J. C. , Concannon A. J. , Dodds A. J.
Published: March 2008

Summary We report the late development of transfusion‐dependent sideroblastic anaemia in two patients who received a bone marrow transplant for chronic granulocytic leukaemia in blast crisis and T‐cell acute lymphoblastic leukaemia respectively. Treatment with pyridoxine has either stopped or reduced these transfusion requirements. Red cell transfusion dependence late after marrow transplantation is rare and sideroblastic anaemia must be excluded.
Abnormal in vitro function of a variant human transferrin
Authors: Young S. P. , Bomford A. , Madden A. D. , Garratt R. C. , Williams R. , Evans R. W.
Published: March 2008

Summary. Normal and variant transferrins have been isolated from the plasma of an individual heterozygous for the abnormal protein. The normal and variant proteins were separated, saturated with 59Fe, labelled with 125I and then compared in their interaction with PHA‐stimulated human lymphocytes in vitro.

At 4°C the variant protein bound to the transferrin receptors on these cells with an association constant (6·25±2·53×107 I mol‐1, mean ± SD; n= 4) which was an order of magnitude lower than that of the normal diferric transferrin (6·31 ± 1·82 × 108 1 mol‐1, mean±SD; n= 4). This low association constant was reflected in a much reduced rate of iron donation to the cells at 37°C (22·2±8·3 pg/106 cells/h compared with 48·1±15·6 pg/106 cells/h).

As the variant transferrin has both abnormal iron‐binding properties (Evans et al, 1982) and an abnormal interaction with the transferrin receptor, it would appear that these two functions may be closely interdependent.
Platelets deficient in glycoprotein I have normal Fc receptor expression
Authors: Pfueller Sharron L. , de Rosbo Nicole Kerlero , Bilston Robyn A.
Published: March 2008

Summary. Platelet glycoprotein I (GPI) is known to be required for the interaction of platelets with ristocetin and factor VIII:von Willebrand factor (VIII:vWf). However, its role as Fc receptor is not clear. Some studies have shown that enzymatic removal of GPI destroys the ability of platelets to react with VIII:vWf but not their ability to bind Ig G (IgG). Others have shown that IgG immune complexes which block the Fc receptor also inhibit VIII:vWf interaction with platelets. This subject has been re‐examined by testing the ability of platelets with reduced amounts of GPI to aggregate and undergo the release reaction in response to stimuli which act at the platelet Fc receptor. Platelets from two patients with Bernard‐Soulier syndrome, congenitally deficient in GPI, both aggregated and released 14C‐serotonin normally when exposed to latex particles coated with IgG. Levels of GPI were decreased experimentally in normal platelets by treating them with chymotrypsin. Platelets treated in this manner did not aggregate or release [14C]serotonin in response to ristocetin‐VIII:vWf. They did, however, both aggregate and release when incubated with heat‐aggregated IgG, antigen‐antibody complexes or latex particles coated with IgG. Thus the presence of GPI is not a prerequisite for platelet stimulation via the Fc receptor.
The effects of low‐dose vincristine on megakaryocyte colony‐forming cells and megakaryocyte ploidy
Authors: Harris R. A. , Penington D. G.
Published: March 2008

Summary. The administration of low‐dose vincristine (VCR) (0.1 mg/kg) to mice resulted in thrombocytosis without prior thrombocytopenia. No significant changes in marrow megakaryocyte numbers were found. However, after a minor early decrease, mean megakaryocyte ploidy increased, with a peak at 3 d. The number of megakaryocyte colony‐forming cells (MEG‐CFC) in bone marrow did not change significantly. In contrast with the effects on marrow, the concentration of megakaryocytes and the content of MEG‐CFC in the spleen were significantly reduced for 1–2 d after VCR. This reduction was followed by a compensatory rise in the splenic content of MEG‐CFC (peak 3‐fold increase at 3 d), and 1–2 d later, an increase in splenic megakaryocytes which was concurrent with the increased platelet count. Culture of marrow and spleen cells in the presence of VCR resulted in inhibition of megakaryocyte colony formation at concentrations > 5 ng/ml and parallel reduction of the number of megakaryocytes per colony and the mean ploidy of colony megakaryocytes.

The results suggest that the thrombocytosis induced by low‐dose VCR does not result simply from an effect on platelets, but reflects compensatory changes in megakaryopoiesis secondary to toxic suppression of megakaryocytes and their progenitors.
Production and availability of thromboplastin in endothelial cells: the effects of thrombin, endotoxin and platelets
Authors: Brox J. H. , ØSterud B. , Bjørrlid E. , Fenton J. W.
Published: March 2008

Summary. Freshly prepared endothelial cells from umbilical cord veins were demonstrated to possess a weak but significant thromboplastin activity. Upon exposure of cultured endothelial cells to catalytically active thrombin (4.5 U/ml) or endotoxin (0.05 μg/ml), the thromboplastin activity of the cells was increased 10–40‐fold during 5 h incubation, and with the additional presence of washed, isolated platelets during the incubation, the activity was enchanced up to 170‐fold. Platelets or catalytically inactivated thrombin added alone were largely ineffective as stimulants. 75–80% of the enhanced thromboplastin activity became available on the surface of the cultured cells as demonstrated by utilizing thromboplastin antibodies. Such exposed activity is suggested to be important in thrombotic situations where initial formation of thrombin may significantly accelerate the generation of thrombin by a positive feedback effect upon thromboplastin synthesis in the endothelial cells.
Population and genetic studies suggest a single origin for the Indian deletion β° thalassaemia
Authors: Thein S. L. , Old J. M. , Wainscoat J. S. , Petrou M. , Modell B. , Weatherall D. J.
Published: March 2008

Summary. In a study of β thalassaemia in the Asian Indian immigrant populations in the U.K., 23 out of 125 β‐Thalassaemic chromosomes (18%) were of the Indian deletion β° type (600 bp deletion involving the 3’ end). The individuals with β thalassaemia had originated from various parts of India and Pakistan. However, all those individuals with deletion β° thalassaemia were from Sind and the adjacent area of Gujarat. Analysis of restriction fragment length polymorphisms in the β globin gene cluster showed that all the 23 deletion β° thalassaemia chromosomes had an indentical haplotype. These findings suggest a single origin for the Indian deletion β° thalassaemia.
The use of intermediate dose cytosine arabinoside (ID Ara‐C) in the treatment of acute non‐lymphocytic leukaemia in relapse
Authors: van Prooijen H. C. , Dekker A. W. , Punt K.
Published: March 2008

Summary. Cytosine arabinoside in a high dose of 3 g/m2 (HD Ara‐C), alone or in combination with doxorubicin, has been advocated for the treatment of patients with acute non‐lymphocytic leukaemia (ANLL) in relapse. Although a remission rate of 65% has been reported, the toxicity was severe and was possibly related to the high plasma concentrations of Ara‐C (about 100 μm) reached during 1 h infusion. It has been postulated, however, that the intracellular enzymes which convert Ara‐C into the active metabolite cytosine arabinoside triphosphate (Ara‐CTP), are saturated at plasma concentrations of about 10 μM. We calculated that this level could be reached with an intermediate dose of 0.5 g/m2 Ara‐C, given in a 1 h infusion (ID Ara‐C). Subsequently 15 patients with ANLL (12 in relapse and three refractory to conventional therapy) were treated with ID Ara‐C every 12 h for 6 d in combination with doxorubicin and vincristine. The overall remission rate was 80%. The median duration of bone marrow depression was 20 d (range 14–29 d) and side effects were comparable to conventional treatment. These preliminary data suggest that the therapeutic results of this ID Ara‐C regimen are not inferior to comparable schedules with HD Ara‐C as reported by others while toxicity is less severe.
K cell mediated haemolysis: influence of large numbers of unsensitized cells on the antibody‐dependent lysis of anti‐D‐sensitized erythrocytes by human lymphocytes
Authors: Bakács Tibor , Kimber Ian , Ringwald Gabor , Moore Michael
Published: March 2008

Summary. The inhibition of K cell mediated haemolysis of anti‐D‐sensitized human red blood cells by unsensitized erythrocytes has been demonstrated. Inhibition of lysis was non‐competitive in nature and influenced by the size and number of unsensitized cells. However, even in the presence of high inhibitor: target cell ratios (50:1) haemolysis, although reduced, was still effected suggesting that K cells are highly motile and capable of recognizing and destroying minority populations of antibody‐sensitized erythrocytes. These data are compatible with a role for cytotoxic lymphocytes in the intravascular lysis of autoantibody or alloantibody‐sensitized red cells.
Use of Adsol® preservation solution for prolonged storage of low viscosity AS‐1 red blood cells
Authors: Heaton A. , Miripol J. , Aster R. , Hartman P. , Dehart D. , Rzad L. , Grapka B. , Davisson W. , Buchholz D. H.
Published: March 2008

Summary. A new red cell preservation solution is described in which the red cells may be stored for 49 d with greater than 75% mean post‐transfusion recovery. Blood is drawn into Anticoagulant Citrate Phosphate Dextrose Solution, centrifuged, the plasma removed and the cells resuspended in 100 ml of a solution containing saline, adenine, dextrose and mannitol (Adsol Preservation Solution, Fenwal Laboratories, Deerfield, Illinois). The final product, AS‐1 Red Blood Cells, has a haematocrit of approximately 0.60 and flow properties that are similar to those of whole blood. After storage, red cell haemolysis is minimal and erythrocyte adenosine triphosphate is well preserved. This study documents that red cells may be stored in a protein‐poor electrolyte medium for periods of 49 d with good post‐transfusion survival.
Book Review
Authors: Wardle Jane M.
Published: March 2008

Blood Cell Volume Analysis – A New Screening Technology for the Haematologist. By R. M. Rowan.
Hybridoma antibodies to human von Willebrand factor
Authors: Meyer Dominique , Baumgartner H. R. , Edgington T. S.
Published: March 2008

Summary. Hybridoma antibodies specific for seven independent topographical sites were used to characterize von Willebrand factor (vWF) and to relate the epitopes to functional loci required for vWF‐mediated adhesion of platelets to subendothelium and ristocetin‐induced platelet aggregation. The capacity of antibodies to influence the adhesion of human platelets to rabbit aortic subendothelium was analysed in annular perfusion chambers. At a high shear rate similar to that of the microcirculation, four monoclonal antibodies inhibited adhesion. In contrast, no inhibition was observed at low shear. Only one of the four antibodies that inhibited platelet adhesion also attenuated ristocetin‐cofactor activity (VIIIR:RCo). Conversely, one antibody that inhibited VIIIR:RCo had no effect upon platelet adhesion. These data support the hypothesis that the molecular loci involved in the two biological functions of vWF are not identical. When these conclusions are considered within the context of a spatial map of the vWF protein surface developed by competitive displacement analysis, the epitopes related to platelet adhesion appear to be spaced and differ from those involved in ristocetin‐induced platelet‐platelet interaction.
A monoclonal antibody binding to human medulloblastoma cells and to the platelet glycoprotein IIb‐IIIa complex
Authors: Jones Dawn , Fritschy Jean , Garson J. , Nokes T. J. C. , Kemshead J. T. , Hardisty R. M.
Published: March 2008

Summary. A monoclonal antibody, designated M148, produced by the hybridoma technique from spleen cells of mice immunized with human medulloblastoma, was found by indirect immunofluorescence to bind to normal human platelets (both PlAl positive and PlAl negative) and megakaryocytes, as well as to some medulloblastoma and neuroblastoma cells and cell lines and certain other solid tumours. No binding was observed to other marrow constituents, nor to any other normal tissue examined. The antibody bound to platelets from a patient with the Bernard‐Soulier syndrome but not to thrombasthenic platelets. It immunoprecipitated glycoproteins IIb and IIIa from 125I‐labelled normal platelet membranes, and completely inhibited ADP‐induced fibrinogen binding and aggregation of platelets. Aggregation was also inhibited in response to adrenaline, collagen, thrombin, sodium arachidonate and the ionophore A23187; clot retraction was partially inhibited. The antibody was without effect on thromboxane formation or 5‐hydroxytryptamine (5HT) secretion in response to thrombin, but inhibited 5HT secretion in response to arachidonate. It did not inhibit factor VIII binding or agglutination in response to ristocetin, but completely inhibited factor VIII binding in response to thrombin. These findings suggest that the epitopes are close to the fibrinogen and factor VIII binding sites on glycoproteins IIb/IIIa, and that the lack of these glycoproteins is sufficient explanation for the pattern of dysfunction observed in thrombasthenic platelets, without invoking any other membrane abnormality.
Fractionation of human antibody to factor VIII:C: an IRMA for phospholipid binding sites on factor VIII C: Ag
Authors: Kemball‐Cook G. , Barrowcliffe T. W.
Published: March 2008

Summary. Labelled Fab’ fragments, derived from the plasma of a severe haemophiliac with antibody directed against factor VIII clotting antigen (VIII C:Ag), were fractionated by immunoabsorption with, first, a complex of phospholipid (PL) vesicles and factor VIII and, second, with factor VIII alone. Two pools of labelled anti‐VIII C:Ag were obtained and were used in immunoradiometric assays (IRMAs) for VIII C:Ag. With one pool (non‐PL‐site antibody) VIII C:Ag assays were unaffected by pre‐incubation of factor VIII with PL vesicles; however, binding of the second pool of antibody to VIII C:Ag was prevented by PL preincubation, indicating that these antibody molecules bind at or near a phospholipid binding site on VIII C:Ag (PL‐site antibody). Assays of VIII C:Ag in an intermediate purity factor VIII concentrate with these two antibody pools indicate that more than one third of the VIII C:Ag may be bound to PL.
Prognostic significance of vacuoles in L1 lymphoblasts in childhood acute lymphoblastic leukaemia: a report from Children's Cancer Study Group
Authors: Potter Virginia P. , Sorell Michael , Baglivo Jenny A. , And Harland Sather , Miller Denis R.
Published: March 2008

Summary.From February 1975 to February 1977, 880 patients with acute lymphoblastic leukaemia were enrolled on Children's Cancer Study Group protocol 141 designed to evaluate prognostic factors and more intensive therapy for patients with poor prognosis. 765 diagnostic bone marrow aspirates from 23 institutions were available for classification using the French‐American‐British system. 60 of 615 patients with L1 morphology had vacuolated lymphoblasts. Patients with vacuolated lymphoblasts had a better disease‐free survival (P= 0.14) and a significantly better survival (P= 0.03) but the presence of vacuoles was associated with a low initial WBC and an age range associated with improved prognosis for disease‐free and over‐all survival.
Management of planned pregnancy in a patient with congenital antithrombin III deficiency
Authors: Samson Diana , Stirling Yvonne , Woolf Linda , Howarth D. , Seghatchian M. J. , Chazal R. de
Published: March 2008

Summary. Long‐term warfarin therapy was changed to subcutaneous heparin to cover a planned pregnancy in a patient with congenital antithrombin III (AT III) deficiency. Satisfactory anticoagulation was easily maintained in spite of low levels of biologically active AT III. Delivery and the puerperium were covered by a reduced dose of heparin and alternate day infusions of AT III concentrate. A mean dose of 0.77 U/kg of AT III concentrate produced a rise of 1% in AT III and the half‐life was of the order of 24 h, with no evidence of increased consumption during labour and delivery. Pregnancy and labour were uncomplicated and resulted in delivery of a healthy female infant. The importance of early and adequate anticoagulation during pregnancy is emphasized.
Dutch β°‐thalassaemia: a 10 kilobase DNA deletion associated with significant γ‐chain production
Authors: Gilman J. G. , Huisman T. H. J. , Abels J.
Published: March 2008

Summary. A unique β°‐thalassaemia in a Dutch family results in fetal haemoglobin expression comparable to that of δ°β°‐thalassaemia. Haemoglobin analysis and restriction endonuclease mapping studies of DNA suggest that the β‐globin gene is entirely deleted, but that the δ‐globin gene is intact. The 5’break point of the deletion is 3–4 kilobases 3’to the δ‐globin gene, while the 3’break point is 6–7 kilobases 3’to the β‐globin gene (relative to the normal DNA restriction map). The result is a ˜ 10 kilobase deletion of DNA whose 3’end point may lie very close to that for one δ°β°‐thalassaemia, within a cluster of Kpn I‐family repetitive sequences. The Dutch β°‐thalassaemia deletion is thus the shortest one which, in the absence of additional chromosomal rearrangements, results in enhancement of γ‐chain synthesis above that seen for haemoglobin Lepore. These data support the hypothesis that the region of DNA 3’to the β‐globin gene may be important to the developmental regulation of fetal γ versus adult β chain production.