bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Hyperoxia on Superoxide Anion and Hydrogen Peroxide Production of Polymorphonuclear Leucocytes and Alveolar Macrophages
Authors: Rister M. , Baehner R. L.
Published: March 2008

Hyperoxia activates superoxide dismutase (SOD) while inactivating catalase and glutathione peroxidase in polymorphonuclear leucocytes (PMN) and alveolar macrophages (AM) obtained from guinea‐pigs exposed to 85% oxygen for 90 h. The influence of these altered enzyme activities on the rate of oxygen consumption and release of superoxide anion (O) and hydrogen peroxide (H2O2−) was investigated. By 18 h O2− released from resting PMN increased two‐fold and remained elevated through the entire periods of the study, whereas H2O2− release and oxygen consumption at the same time points remained normal. At 66 h PMN phagocytizing opsonized zymosan particles released additional quantities of O2− and H2O2− and consumed significantly more oxygen compared to the usual increase noted at earlier time points. Although oxygen consumption was almost two‐fold higher in AM than PMN, phagocytizing AM released three‐fold less O2− and fivefold less H2O2− than did PMN. Furthermore, AM of animals exposed to hyperoxia no longer exhibited enhanced O2− production upon exposure to opsonized zymosan. Hydrogen peroxide release progressively decreased at rest but progressively increased during phagocytosis of opsonized zymosan during the 90 h exposure to hyperoxia. No changes in oxygen consumption of AM occurred during hyperoxia. The divergent oxidative responses in PMN and AM of guinea‐pigs exposed to hyperoxia suggest different biochemical adaptive mechanisms.
Serum Ferritin in Haemochromatosis: Changes in the Isoferritin Composition during Venesection Therapy
Authors: Halliday J. W. , Mckeering L. V. , Tweedale R. , Powell L. W.
Published: March 2008

The isoferritin composition of serum ferritin in 13 patients with untreated idiopathic haemochromatosis (IHC) has been shown to differ from normal in exhibiting an increase in isoferritins in the pH range 5.54–5.62. A similar change was observed in four patients with gross iron overload secondary to haemolytic anaemia. During the course of venesection therapy there was a progressive rise in isoferritins of pI 5.02–5.06 relative to the more basic isoferritins. These observations are consistent with previous studies showing alterations in tissue isoferritins in untreated IHC before and after venesection therapy and they are compatible with the hypothesis that the more basic isoferritins correspond to a ‘storage’ferritin and the more acidic to a ‘secretory’ferritin. The studies also provide further evidence for a possible biological role of the individual isoferritins.
The Effect of Androstanes on Granulopoiesis in Vitro and in Vivo
Authors: Francis G. E. , Berney J. J. , Bateman S. M. , Hoffbrand A. V.
Published: March 2008

Summary. Bone marrow culture in a patient with aplastic anaemia responding to anabolic steroid (methandienone) therapy, showed an unusually high degree of growth in unstimulated cultures. Growth in unstimulated cultures is due to factors with colony stimulating activity (CSA) released by monocyte macrophages in the bone marrow sample. These cells, which can be identified by staining for non‐specific esterase activity, were not increased in this patient's marrow, implying either increased production of colony stimulating factors or increased sensitivity to these factors. Addition of methandienone or testosterone to feeder‐layers containing normal peripheral blood leucocytes increased their stimulatory activity. Addition of these drugs to feeder‐layers of CSF‐containing conditioned medium did not have this effect, implying that androstanes cause increased production of colony stimulating factors rather than increased sensitivity to them. Lack of response to androstane therapy may be related to lack of response by bone marrow monocyte macrophages or to the inability of granulopoietic cells to respond to the increased CSF production induced by androstane therapy. A means of predicting lack of response is proposed.
Thrombin Activation of Factor VIII: the Effect of Inhibitors
Authors: Rick Margaret E. , Hoyer Leon W.
Published: March 2008

Summary. Factor VIII is a large glycoprotein which can be separated into a high molecular weight component which retains factor VIII‐related antigens and supports ristocetin‐induced platelet agglutination, and a low molecular weight component which has procoagulant activity. It has been suggested that this separation, observed in high ionic strength buffers, might be the consequence of proteolysis by plasma proteins. To consider this possibility, we have examined the interaction of the proteolytic enzyme thrombin with factor VIII. This study, carried out with highly purified materials, has used thrombin‐mediated factor VIII proagulant activation as an indicator of this interaction. Several proteolytic inhibitors have been studied to determine their ability to inhibit factor VIII activation by thrombin. Under the current experimental conditions, diisopropylfluorophosphate (DFP) and hirudin inhibited the reaction, while heparin was an effective inhibitor only when plasma proteins were added. Benzamidine inhibited factor VIII activation when used at high concentrations, and phenylmethyl sulphonylfluoride and soybean trypsin inhibitor were found to be ineffective. These results show that DEP and hirudin prevent thrombin alteration of factor VIII and will be useful in purification and characterization studies of the factor VIII molecule.
Mechanisms of Microtubule Disassembly in Vivo: Studies in Normal and Chronic Granulomatous Disease Leucocytes
Authors: Oliver Janet M. , Berlin Richard D. , Baehner Robert L. , Boxer Lawrence A.
Published: March 2008

Summary. Microtubule assembly in human polymorphonuclear leucocytes is a dynamic process that can be initiated by binding of the plant lectin Concanavalin A to surface receptors. Colchicine inhibits lectin‐induced microtubule assembly and promotes the movement of Concanavalin A into surface caps. Inhibition of microtubule assembly and enhanced Concanavalin A cap formation also follow treatment of normal leucocytes with two specific glutathione‐oxidizing agents, ‘diamide’ and tertiary butylhydroperoxide. Our objective here was to determine if microtubule inhibition is mediated via glutathione disulphide or via hydrogen peroxide that is generated in Concanavalin A‐treated leucocytes and may accumulate when cells are depleted of reduced glutathione. We show that exogenous hydrogen peroxide induces Concanavalin A capping on normal polymorphonuclear leucocytes but only at concentrations that simultaneously oxidize glutathione. We also show that ‘diamide’ and tertiary butylhydroperoxide cause Concanavalin A cap formation in leucocytes from patients with chronic granulomatous disease. These cells cannot generate significant amounts of superoxide or hydrogen peroxide. Thus, it seems likely that the reversible inhibition of microtubule assembly and function caused by glutathione oxidants requires only increased glutathione disulphide and is not dependent on subsequent accumulation of other metabolites.
Increased Survival of Haemopoietic Pluripotent Stem Cells in Vitro Induced by a Marrow Fibroblast Factor
Authors: Blackburn Mary J. , Patt Harvey M.
Published: March 2008

Summary. When mouse bone marrow was incubated in medium conditioned by marrow fibroblasts, the survival of pluripotent stem cells (CFUS) was considerably greater than when marrow was incubated in fresh medium. This increase in CFUS survival depended on the age of the marrow fibroblast culture, the initial number of cells in the culture, and the concentration of the conditioned medium. Medium conditioned by fibroblasts from other adult tissues—spleen, bone, and subcutaneous tissue—did not increase CFUS survival, but medium conditioned by embryo bone did. The increase in CFUS survival by marrow‐fibroblast‐conditioned medium was not accompanied by any change in the total number of nucleated cells of the incubated marrow nor by any comparable increase in the survival of granulopoietic stem cells (CFUC) or erythropoietic stem cells (BFUE). These results indicate that marrow fibroblasts produce a factor that increases the survival of CFUS, which may be involved in the role of marrow stroma in the control of haemopoiesis.
The Fragility of Normal and Abnormal Erythrocytes in a Controlled Hydrodynamic Shear Field
Authors: Williams A. R. , Escoffery C. T. , Gorst D. W.
Published: March 2008

Summary. Fresh human erythrocytes (suspended in a compatible isotonic viscous saline medium containing plasma) were disrupted by the uniform shear stresses generated in the laminar flow field of a conventional cone and plate viscometer. A range of normal fragilities was established and blood samples from patients having certain well‐defined haematological abnormalities were found to be partially or completely outside these limits. The present technique is sensitive enough to distinguish between young and old cell fractions isolated from the same original population and also appears to be able to resolve discrete sub‐populations having different mechanical fragilities within unfractionated samples from certain patients (e.g. macrocytosis). This technique provides additional information which could aid or facilitate diagnosis and might eventually form the basis of a routine screening test in clinical haematology.
The Histone Content of Chromatin Preparations from Leukaemic Cells
Authors: Simpkins H. , Mahon K.
Published: March 2008

Summary. The histone compositions of chromatin preparations obtained from different adult leukaemias were compared and showed differences between myeloid, monoblastic and lymphoblastic types. The differences were observed whether or not the myeloid precursors were mature or blast forms. Mixing experiments revealed that a potent histone protease was present in the myelocyte chromatin fraction which, unlike most histone proteases, appeared not to be inhibited by serine esterase inhibitors. It is concluded that the differences observed in the histone patterns do not reflect the histone composition present in the cell but are created by proteolytic degradation during the isolation procedure. However, these may still provide some help in identifying myeloblasts in undifferentiated leukaemias.
Characterization of Marrow Granulocyte Development: Changes in Response to Inflammatory Reactions
Authors: Scott R. B. , Eanes R. Z. , Cooper Laverne W. , Higgins Linda L. , Eastment Christine A.
Published: March 2008

Summary. Studies of marrow granulocyte differentiation require separation of precursors into populations of varying stages of maturity. This has been accomplished by isopycnic sedimentation of marrow cells in density gradients of Ficoll and Hypaque under conditions in which erythrocyte precursors are virtually eliminated and lymphocyte contamination is small. Immature cells have lower buoyant density and predominate in the top of the gradients and cells of increasing maturity are found as the density level of the gradient increases. Distinct differences were found between control marrows and those of animals with an intense inflammatory response. The inflammatory stimulus depleted the marrow of many mature granulocytes and the immature cell populations were shown to be enriched. Peritoneal exudate cells (mostly mature granulocytes) were shown to have altered buoyant density properties compared to mature granulocytes in marrow. Activity of alkaline phosphatase (a granule‐associated enzyme) increased progressively as cells matured, while lactic dehydrogenase activity (a cytosol enzyme) remained stable.

Protein synthesis in control and stimulated marrows showed two‐ to five‐fold greater synthesis in immature cells compared to nearly mature marrow cells. Successful separation of varying stages of development in granulocytes permits varied studies of cell properties involved in the process of differentiation.
Distribution of Rhesus Antigens on Red Cell Surfaces
Authors: Knox E. G.
Published: March 2008

Summary. Two pieces of evidence suggest different conclusions about the arrangement of the rhesus antigens on the surfaces of red cells. Indirect evidence suggests an ordered arrangement; electron‐microscopic evidence has been interpreted visually as essentially random.

Re‐analysis of electron‐microscopic material, using a form of computer spectral analysis, suggests that the visual interpretation was mistaken, and that the pattern is orderly. The material suggests that the maternally derived and paternally derived proteins are linked into couplets, and that the couplets may be regularly linked or packed, at least at shorter ranges. The material does not at present illuminate the question of longer range periodicity.
Assay and Characterization of the Factor in Porcine and Bovine Plasma which Aggregates Human Platelets
Authors: Evans R. J. , Austen D. E. G.
Published: March 2008

Summary. A sensitive and objective bioassay has been developed to measure the factor present in porcine or bovine plasma which aggregates human blood platelets. The technique is based on direct measurement of platelet aggregation using an electronic particle counter.

Using this assay it has been established that platelet aggregating activity is present in both bovine and porcine plasma and in therapeutic concentrates of factor VIII prepared from these materials. Platelet aggregating activity was found to be a function of the factor‐VIII‐related antigen concentration and independent of factor‐VIII coagulant activity. The activity is absent in the plasma from pigs with von Willebrand's disease. It is concluded that factor‐VIII‐related antigen and the platelet aggregating factor are closely related and may represent one protein species.
SDS Polyacrylamide Gel Characterization of Serum FDP Produced in Response to Ancrod and Streptokinase/Plasminogen Infusions in Man
Authors: Lane D. A. , Robbins Patricia A. , Rampling M. W. , Kakkar V. V.
Published: March 2008

Summary. The serum FDP produced in response to defibrination with ancrod and to thrombolytic therapy with intermittent streptokinase/plasminogen infusion have been characterized using a method of solid phase immuno‐precipitation followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Using this method it is possible to distinguish between the plasmin degradation products of fibrinogen and factor XIIIa induced crosslinked fibrin. During ancrod administration, fragments of similar mobility to fibrinogen fragments X, Y, D and E are present in serum samples taken 24 h after the initiation of treatment, while subsequent samples contain mainly fragments with the same mobility as fibrinogen fiagment D. The intermittent nature of the streptokinase/plasminogen infusions produces fibrinogen fragments X, Y, D and E in the serum 1 h after each daily streptokinase/plasminogen administration. An early clearance of fragment E from the circulation of patients receiving either ancrod or streptokinase/plasminogen infusions accords with the results of other investigations. The presence of the D dimer fragment, which is produced only by plasmin lysis of factor XIIIa crosslinked fibrin, could not be conclusively confirmed in either group of patients.
Cyclic AMP Maintenance of Rabbit Reticulocyte Haem and Protein Synthesis in the Presence of Ethanol and Benzene
Authors: Freedman Michael L. , Spieler Paul J. , Rosman Judith , Wildman Joseph M.
Published: March 2008

Haemin is necessary for maximal protein synthesis in intact reticulocytes and their cell‐free lysate preparations. Under conditions of haemin deficiency a translational protein repressor of initiation (HCRA) forms from a non‐inhibitory form of the same protein (HCR1) and protein synthesis ceases. It has recently been suggested that this repressor is a protein kinase and that high concentrations of 3′,5’cyclic AMP could substitute for haemin in maintaining reticulocyte lysate cell‐free protein synthesis. The present study was undertaken, therefore, to investigate if cAMP had a similar function in intact rabbit reticulocytes. The cells were incubated with eidier epinephrine (10‐6 M), isoproterenol (10‐4 M), theophylline (10‐4 M) or dibutyryl cAMP (10‐4 M). All these compounds elevated the intracellular concentration of cAMP within the first 2 min of incubation, as measured by a specific competitive binding assay. This indicates that rabbit reticulocytes contain both adenyl cyclase and phosphodiesterase systems. The cells were incubated with an inhibitor of haem synthesis (either 0.1 M ethanol or 0.1 M benzene) to form HCRA prematurely and inhibit protein synthesis. When the cells were incubated simultaneously with any one of these inhibitors and either epinephrine, isoproterenol, theophylline or dibutyryl cAMP, there was no inhibition of haem or protein synthesis and no demonstrable HCRA. Furthermore, dibutyryl cAMP reversed the inhibition of both haem and protein synthesis induced by ethanol or benzene. Dibutyryl cAMP relieved the inhibition of haem synthesis prior to relieving the inhibition of protein synthesis, which indicates that sufficient haemin must be present before maximal protein synthesis may resume. In contrast, elevation of cyclic AMP levels did not protect against iron deficiency inhibition of either haem or protein synthesis. This indicates that in intact cells cAMP does not directly convert HCRA to HCR1

On the basis of these findings, we postulate that in intact reticulocytes (in contrast to cell‐free systems) a major role of cAMP is maintenance of maximal haem synthesis, even in the presence of inhibitors. Intracellular haemin concentration appears to be a major control mechanism of protein synthesis via prevention and reversal of HCRA. This model assures a balance between haem and globin synthesis in erythroid precursors.
Quantitation of the Reticuloendothelial System Clearance of Soluble Fibrin
Authors: Sherman L. A. , Lee J. , Jacobson A.
Published: March 2008

Phagocytosis of particulate fibrin has been previously established as a function of the reticuloendothelial system (RES). More recently, reticuloendothelial cells have been shown to bind soluble fibrin/fibrinogen (f/F) complexes in vitro. To quantitate RES clearance us microthrombus formation, varying doses (0.1‐6 mg/kg) of 125I‐soluble f/F was injected into rabbits. One hour later the animals were killed, at which time 48 $pM 8% of the 125I f/F had been cleared from the blood. Homogenized organ samples were separated into insoluble pellet, soluble protein bound, and free 125I. Treatment of other samples with plasmin prior to homogenization differentiated the insoluble 125I into RES cleared (intracellular‐plasmin resistant) vs microthrombi (plasmin sensitive pellet 125I). 125I‐f/F was chiefly found in liver and spleen. Injection of low f/F concentrations resulted in no plasmin sensitive pellet 125I. 3 mg/kg f/F caused small, variable amounts of plasmin sensitive pellet 125I, chiefly in the kidney. With 6 mg/kg, 21‐50% of the insoluble 125I in all organs was plasmin sensitive, and occasional 1–2 mm thrombi were found. The data indicate complete and rapid RES clearance of small amounts of soluble f/F from the blood, without microthrombi being formed. The RES was acutely saturated at 1.5–3.0 mg f/F/kg, which is equivalent to immediate conversion to fibrin of 1–2% of the intravascular fibrinogen pool.
An Immunoenzyme Histochemical Technique for the Detection of Platelet Antibodies from the Serum of Patients with Idiopathic (Autoimmune) Thrombocytopenic Purpura (ITP)
Authors: Tate D. Y. , Sorenson R. L. , Gerhard J. M. , White J. G. , Krivit W.
Published: March 2008

The present report describes a simple, reproducible, semi‐quantitative immunohistochemical assay for the detection of antiplatelet antibody. Evaluation of the technique in 10 children with active idiopathic (autoimmune) thrombocytopenic purpura (ITP), seven children with thrombocytopenia due to other causes, and 12 normal individuals revealed that the assay consistently and reliably distinguished children with ITP from the other groups. Individuals who had had multiple platelet transfusions and individuals with systemic lupus erythematosus (SLE) also had antiplatelet antibodies detectable using this technique although the levels were less than those of individuals with ITP. The method can be used effectively to monitor the course of ITP and the effects of therapy.
Platelet Autoimmunity
Authors: Chanarin I. , James D. , Stafford Denise , Tidmarsh Elizabeth
Published: March 2008

Autoimmunity to platelets was looked for by complement fixation, antiglobulin consumption, transformation and migration‐inhibition techniques. Only the migration‐inhibition method gave consistently positive results. The test was positive in nine out of 14 patients with idiopathic thrombocytopenic purpura and all five patients with glandular fever.
Non‐Tropical ‘Idiopathic Splenomegaly’: a Follow‐up Study of Ten Patients Described in 1969
Authors: Dacie J. V. , Galton D. A. G. , Gordon‐Smith E. C. , Harrison C. V.
Published: March 2008

The later history is described of four of 10 patients who were reported in 1969 as suffering from non‐tropical ‘idiopathic splenomegaly’. Two of the four patients developed malignant lymphomas 6 years and 2 years, respectively, after splenectomy but the two other patients have lived for 17 and 15 years, respectively, without developing any signs of a malignant tumour. Thus, four of the original 10 patients have developed malignant lymphomas. The histology of the patients' spleens has been reviewed in the light of their clinical history, but no criteria have been found which are of clear prognostic value. However, with hindsight it was possible to recognize some cytological abnormality in the spleens in three out of the four patients who developed malignant lymphomas, and it appears that unless the cell population in both the red and white pulp is strictly normal, the patient is likely to develop a malignant lymphoma. The tumours which subsequently developed showed no special or characteristic features. The title ‘idiopathic splenomegaly’ is clearly unsatisfactory but the alternative ‘chronic lymphocytic lymphoma with hypersplenism’, although appropriate for the illness of the patients who developed malignant lymphomas, is inappropriate for those in which the pathological process seems not to be neoplastic.
Evidence that Endotoxins Enhance the Factor X Activator Activity of Washed Human Platelets
Authors: Semeraro N. , Fumarola D. , Mertens F. , Vermylen J.
Published: March 2008

The in vitro effect of several bacterial endotoxins on human platelets was determined. Nine different endotoxins failed to induce aggregation in platelet‐rich plasma (PRP) or of platelets washed by two different methods; four of them which we studied further failed to induce [14C]serotonin release in PRP. In contrast, using recently described test systems for platelet coagulant activity, all the endotoxins shortened the latent period occurring before aggregation of a mixture of washed platelets, normal serum, and CaCl2, and the clotting time of this mixture upon addition of fibrinogen. Washed platelets obtained from PRP preincubated with endotoxin had a higher platelet coagulant activity than platelets obtained from PRP preincubated with buffer. Washed platelets contribute to thrombin generation by providing factor V, a factor X activator and possibly phospholipid. Since the endotoxins did not influence the factor V activity of platelets or the platelet factor 3 activity, either in PRP or using platelets washed by albumin density gradient centrifugation, it is suggested that they enhance the factor‐X activator activity of human platelets.
Impairment of Platelet Thromboxane A2 Generation and of the Platelet Release Reaction in Two Patients with Congenital Deficiency of Platelet Cyclo‐oxygenase
Authors: Lagarde Michel , Byron Paul Andre , Vargaftig Bernardo B. , Dechavanne Marc
Published: March 2008

Two cases of thrombocytopathia with congenital deficiency of platelet cyclo‐oxygenase were investigated. The platelet release reaction was impaired. There was a marked decrease of aggregation with collagen and with adrenalin and a total absence of aggregation with sodium arachidonate. The platelet response to labile aggregation stimulating substance (LASS, mostly thromboxane A2) was normal. There was no biosynthesis of prostaglandin cyclic endoperoxides or of thromboxane A2 from arachidonic acid. Basal levels of platelet PGE1 were lowered although plasma levels were normal. Thrombin decreased the cyclic AMP content of patients' platelets and also that of control platelets pretreated with aspirin. The patients' platelets showed no ultrastructural difference when compared with control platelets, except for a slight decrease of granule volume, but, in contrast to control platelets, thrombin (0.02 U/ml) did not provoke contraction of the patients' platelets.
Recommendations for Measurement of Serum Iron in Human Blood*
Authors:   International Committee for Standardization in Haematology
Published: March 2008

The following method has been approved by the International Committee for Standardization in Haematology (ICSH) Board for publication as an ICSH standard (EP7/1978).
Acquired Haemoglobin H Disease in Leukaemia: Pathophysiology and Molecular Basis
Authors: Weatherall D. J. , Old J. , Longley J. , Wood W. G. , Clegg J. B. , Pollock A. , Lewis M. J.
Published: March 2008

A case of the acquired form of haemoglobin H disease is described in an 81‐year‐old male whose illness terminated in acute myeloblastic leukaemia. At presentation the peripheral blood showed two red cell populations; the majority of the cells were markedly hypochromic but there was a small normochromic population. The presenting symptoms were unusually severe for the degree of anaemia; this was because of the presence of large amounts of haemoglobin H which resulted in a high oxygen affinity state. Haemoglobin synthesis studies, both in intact cells and in a cell free system, showed an almost total absence of α chain synthesis in the abnormal cell line. cDNA/mRNA hybridization analysis showed that there was a marked reduction of α chain mRNA in the peripheral blood. However, cDNA/DNA hybridization analysis indicated that the α globin genes were intact in DNA prepared from both peripheral blood and bone marrow. These findings indicate that, unlike the genetic form of haemoglobin H disease, the acquired variety does not result from deletions of the α globin genes but rather from a defect in globin gene transcription involving both sets of haploid genes in the neoplastic cell line. Furthermore they provide evidence for involvement of the red cell series early in a condition which terminated in acute myeloblastic leukaemia.
Immunologic Characterization and Quantification of Haemoglobin A1c
Authors: Javid Jamshid , Pettis Penelope K. , Koenig Ronald J. , Cerami Anthony
Published: March 2008

Sheep antiserum developed against the human glycohaemoglobin, Hb A1c, distinguishes this fraction from the major component Hb A0. Partial cross reactivity is observed with Hb A1a and Hb A1b, as well as with analogous glycohaemoglobins from mouse and dog haemolysates. The reactivity of the haemoglobins with this specific antiserum is abolished by the reduction of the keto group of the sugar ligand.

The immunological specificity displayed provides the basis of a quantitative assay for Hb A1c, suitable for studies of clinical and experimental diabetes.
Maturation Linked Expression of a Myeloid Cell Surface Antigen
Authors: Roberts Marion M. , Greaves M. F.
Published: March 2008

An antiserum raised against myelomonocytic and monocytic leukaemia cells has been used to define a cell surface antigen shared by normal and leukaemic cells of the granulocyte and monocyte cell lines. The quantitative expression of this antigen was investigated using the Fluorescence Activated Cell Sorter and was shown to correlate with the degree of morphological maturation.
An Inhibitor of Fibrin Formation in Thromboplastins Prepared by Saline Extraction of Human Brain
Authors: Duncan B. McL. , Lloyd J. V.
Published: March 2008

Human brain is a common source of thromboplastin for the prothrombin time, where the end point is the conversion of fibrinogen to fibrin. Experiments showed that human brain also contains a proteolipid which inhibits the conversion of fibrinogen to fibrin. The proteolipid is removed when brain tissue is washed with acetone, but remains as a contaminant when brain is extracted with saline. For this reason prothrombin times on the same plasma are longer when saline extracts, rather than acetone dried preparations, are the source of thromboplastin. The proteolipid explains why the prothrombin time becomes shorter when saline extracts are diluted to standardize their activity against the British comparative thromboplastin.
Neutralization of Heparin in Plasma by Platelet Factor 4 and Protamine Sulphate
Authors: Michalski R. , Lane D. A. , Pepper D. S. , Kakkar V. V.
Published: March 2008

The neutralization of heparin by protamine sulphate and platelet factor 4 (PF4) has been studied using kaolin cephalin clotting time (KCCT), thrombin clotting time (TCT) and anti‐Xa assays to measure residual heparin levels. Protamine sulphate and purified PF4 had almost equivalent neutralizing ability on a weight basis regardless of which assay system was used. Plasma samples that were heparinized in vitro could be totally and readily neutralized by both agents in all of the assay systems used. However, when heparinized plasma samples were obtained following intravenous injection of the drug different results for neutralization were obtained depending on the heparin assay used. When residual heparin was measured by anti‐Xa assay partial neutralization of heparin was observed even in the presence of a large excess of neutralizing agent. The same in vivo derived heparinized plasma samples had no heparin activity following neutralization if residual heparin was measured by KCCT and TCT assays. Further ion exchange chromatography experiments demonstrated that the heparin‐like activity that could not be neutralized in the anti‐Xa assay was not adsorbed by the resin ECTEOLA‐cellulose, and therefore could not be removed from plasma by this technique. These results suggest, therefore, that part of the plasma anti‐Xa activity produced following intravenous injection of heparin differs from the anti‐Xa activity obtained following addition of the drug to plasma in vitro.
Immune Complexes in Myelofibrosis: a Possible Guide to Management
Authors: Lewis C. M. , Pegrum G. D.
Published: March 2008

Using a fluorescent technique intracellular immune complexes were found in the peripheral leucocytes in all of 12 patients with myelofibrosis studied. Fluorescent cells varied from 12% to 81%; with no relation to the total white count or any obvious clinical finding.

Three of the patients with severe refractory anaemia benefited from immunosuppressive therapy.
A Quantitative Assessment of Neutrophil Marrow in Seven Patients with Chronic Granulocytic Leukaemia
Authors: Dancey J. T. , Vadnais‐Metz L. H.
Published: March 2008

Neutrophil marrow cellularity was determined in seven patients with chronic granulocytic leukaemia (CGL). The size of the mitotic pool (promyelocytes and myelocytes) and the number of metamyelocytes and bands and of segmented neutrophils in the postmitotic pool were determined from measurements of neutrophil—erythroid ratios in marrow biopsy sections and ferrokinetic estimates of marrow normoblasts. A section mitotic index was calculated in each patient from the numbers of mitotic figures and mitotic pool cells counted on marrow sections. Basal values previously established in normal subjects for the mitotic pool, for metamyelocytes and bands, and for segmented neutrophils, were 2.11 ± 0.36 × 109 cells/kg, 3±33 ±0.61 × 109 cells/kg, and 2.26 ±0.42 × 109 cells/kg, respectively (± 1 SD, n= 13). The basal section mitotic index was 0.07 ± 0.01 (± 1 SD, n= 13). In the seven patients with CGL the mitotic pool comprised 3±71–25±70 × 109 cells/kg, metamyelocytes and bands 7±70–51.02 × 109 cells/kg, and segmented neutrophils 3±45–28±81 × 109 cells/kg. Mitotic indices ranged from 0.04 to 0.10. No relationship was found between marrow cellularity and blood neutrophil count. A negative correlation existed between mitotic pool cellularity and mitotic index (±=−0.76, n= 7 pairs). The results provide quantitative affirmation of neutrophil marrow hyperplasia and of increased neutrophil production by the marrow in CGL.
Unmasking Covert Folate Deficiency in Iron‐Deficient Subjects with Neutrophil Hypersegmentation: dU Suppression Tests on Lymphocytes and Bone Marrow
Authors: Das Kshitish C. , Herbert Victor , Colman Neville , Longo Dan L.
Published: March 2008

Fifteen patients with apparently uncomplicated iron‐deficiency anaemia were studied to determine the presence of covert folate or vitamin B12 deficiency. None had morphologic or conventional biochemical evidence of folate or vitamin B12 deficiency on admission, except for neutrophil hypersegmentation in peripheral blood smears of 10 of the 15 patients, and giant metamyelocytes in some of the bone marrow aspirates.

Although deoxyuridine (dU) suppression tests on pretreatment bone marrow were normal in all 15 patients, similar tests on pretreatment transformed lymphocytes were characteristic of folate deficiency in eight of 14 patients (57%), with poor transformation obscuring results in the fifteenth subject.

After six patients were given 6 weeks of oral folate and iron therapy, the dU suppression test was repeated in the lymphocytes of two subjects who demonstrated folate deficiency in this test on admission. The test still showed folate deficiency, supporting our prior report that the test was useful as a marker of past folate deficiency despite intervening folate therapy.

The nine remaining subjects received iron alone for 3–6 weeks, which produced no change in serum folate, red cell folate, or dU suppression tests in lymphocytes. In five of the nine subjects (56%), however, an abnormality characteristic of folate deficiency appeared for the first time in bone marrow dU suppression tests, with morphologic megaloblastosis developing frankly in four and equivocally in one. Four of these five subjects had a folate corrected defect in the lymphocyte dU suppression test before treatment, and the fifth was the subject in whom lymphocytes did not transform sufficiently to allow testing for the defect.

These observations: 1. Suggest that when a patient with apparently uncomplicated iron deficiency has hypersegmentation of his granulocyte nuclei, underlying folate deficiency should be sought. It was found in nine of the 10 current such subjects. 2. Suggest that the most sensitive test to detect covert folate deficiency in contrary to the situation in severe uncomplicated deficiency of vitamin B12 or folate, in which hypersegmentation is striking and rapid scanning of a hundred neutrophils yields a minimum of five with more than five lobes.

In uncomplicated iron deficiency, iron binding capacity is almost always elevated above 400 μg/dl. Such levels were seen in only four of our 15 patients, two without hypersegmentation and two with hypersegmentation. This may suggest that a patient population with relatively low total iron binding capacity, perhaps often in association with liver disease, is more likely to have covert folate deficiency with their iron deficiency.
A Unique Thalassaemic Syndrome: Homozygous α‐Thalassaemia + Homozygous β‐Thalassaemia
Authors: Loukopoulos Dimitris , Loutradi Aphrodite , Fessas Phaedon
Published: March 2008

The disturbed balance of globin chain synthesis is a major factor in the pathophysiology of the thalassaemic disorders; this concept is strongly supported by the study of a patient displaying an extreme but symmetrical deficit of both major types of chains α and β. The patient had a mild clinical picture but presented a striking hypochromia (MCH 10 pg) with compensatory erythrocytosis (RBC 1012l.). Study of the propositus and his family by haematological, biochemical and biosynthetic techniques indicates that the patient carries two α‐ and two β‐thalassaemia genes resulting in balanced globin chain synthesis; in addition, several members of the family carry two or three abnormal genes. During observation a change in the haematological pattern occurred with a shift towards more intensive β‐chain and away from γ‐chain synthesis; this appeared with be associated with improvement of his anaemia through more effective erythropoiesis.
In Vivo and in Vitro Variations of Human Erythrocyte Glutathione Peroxidase Activity as Result of Cells Ageing, Selenium Availability and Peroxide Activation
Authors: Perona G. , Guidi G. C. , Piga A. , Cellerino R. , Menna R. , Zatti M.
Published: March 2008

Cases showing erythrocyte glutathione peroxidase (GSH‐Px) defects have been previously described. Our experiments demonstrate that a number of non genetic factors may influence the GSH‐PX activity in human erythrocytes.

Selenium administration in vivo was followed in four subjects by elevation in erythrocyte GSH‐Px activity ranging from 30% to 1400%. Selenium operates mainly in the bone marrow erythroblasts by facilitating the synthesis of active GSH‐Px molecules; experiments in vitro demonstrate that, in the youngest erythrocytes, selenium can raise the enzyme activity, but by a different mechanism. The reticulocyte GSH‐Px activity appears to depend on selenium availability and may vary over a wide range. In some normal and iron deficient subjects, the GSH‐Px activity in the youngest erythrocyte fraction was equal or lower than that previously found in whole erythrocytes of patients affected by haemolytic anaemia.

During erythrocyte life, GSH‐Px activity may either diminish or increase, and these variations are inversely related to the initial GSH‐Px activity in the youngest cells. In vitro experiments with the addition of acetyl‐phenyl‐hydrazine strongly suggest that elevation of GSH‐Px activity may be due to allosteric enzyme activation by activated oxygen.
Estimation of Ferrokinetic Parameters by a Mathematical Model in Patients with Primary Acquired Sideroblastic Anaemia
Authors: Barosi G. , Cazzola M. , Morandi S. , Stefanelli M. , Perugini S.
Published: March 2008

Ferrokinetic parameters were estimated in eight patients with primary acquired sideroblastic anaemia (PASA) by means of a mathematical model of iron kinetics. Both plasma 59Fe clearance and red cell utilization curves were used to identify the model parameters. The close agreement between experimental and theoretical data proved that the model can describe iron kinetics in sideroblastic anaemia. Ineffective erythropoiesis was found to be the major factor in the production of the anaemia. Various degrees and patterns of peripheral haemolysis were observed. The storage iron was always markedly increased and a large non‐erythroid iron turnover was calculated in the most severely affected patients. The results are compared with present knowledge of erythropoiesis in PASA.
Destruction of IgG‐Sensitized Erythrocytes by Human Blood Monocytes: Modulation of Inhibition by IgG
Authors: Fleer A. , van der Meulen F. W. , Linthout Els , von dem Borne A. E. G. Kr. , Engelfriet C. P.
Published: March 2008

The in vitro interaction between monocytes and erythrocytes sensitized with non‐complement binding IgG antibodies (i.e. the Rh antibody anti‐D:EAIgG anti‐D) is completely inhibited by low concentrations of IgG (e.g. 30–100 μg/ml). However, the interaction between monocytes and erythrocytes sensitized with IgG anti‐A (EAIgG anti‐A) is not inhibited by IgG. The findings presented in this paper indicate that this difference is probably due to the difference in the number of IgG antibody molecules per EAIgG. Thus, the higher the number of IgG antibody molecules per EAIgG, the less the interaction between EAIgG and monocytes is inhibited by IgG.

A second factor which proved to have a strong influence on inhibition by IgG was the number of EAIgG per monocyte. When the number of EAIgG per monocyte was increased from 1 to 32, the percentage of inhibition by a fixed amount of IgG (50 μg/ml) decreased significantly. This in vitro effect is only evident when relatively weakly sensitized erythrocytes are used and, in vivo, destruction of these weakly sensitized red cells (e.g. EAIgG anti‐D) is confined to the spleen. Since a considerable haemoconcentration occurs in this organ, it is conceivable that a high EAIgG:macrophage ratio is accomplished. The latter data are an indication that this high ratio may allow interaction between weakly sensitized erythrocytes and splenic macrophages despite the presence, in vivo, of a high concentration of IgG, and that, in this way, in the spleen, the inhibitory effect of IgG is overcome.
Lactoferrin Content of Peripheral Blood Cells
Authors: Bennett Robert M. , Kokocinski Theresa
Published: March 2008

The peripheral blood of 60 normal adults was separated into plasma, red cells, neutrophils, lymphocytes, monocytes and platelets. Lactoferrin concentrations were measured in the plasma and cell extracts and compared to those of lysozyme. The neutrophil lactoferrin content in males and post‐menopausal females was found to be significantly higher than in pre‐menopausal females. A small amount of lactoferrin was found in association with monocytes, but not with lymphocytes, erythrocytes and platelets. Neutrophil lysozyme concentrations did not exhibit any variation with sex and age; but the level in monocytes was higher than that in neutrophils. No correlation was observed between individual neutrophil lactoferrin values and the plasma level. Immunofluorescent studies showed neutrophils to have a lobulated pattern suggestive of nuclear staining. Monocytes did not show direct staining, but exhibited a peripheral pattern after prior exposure to lactoferrin—confirming the existence of a surface receptor. Gel chromatography indicated that neutrophil lactoferrin is in a polymerized or complexed form which elutes with the void volume on Sephadex G‐200; serum lactoferrin consists of two forms, one of which also elutes with the void volume on Sephadex G‐200.
Studies of Erythrocyte Membrane Loss Produced by Amphipathic Drugs and in Vitro Storage
Authors: Greenwalt Tibor J. , Lau Francis O. , Swierk Ellen M. , Williams Robert E.
Published: March 2008

Four amphipathic drugs, primaquine, propranolol, chlorpromazine and tetracaine, were used to cause endocytosis in glucose‐depleted red cells, and the relative reduction of membrane surfaces was measured by the toluidine blue (TB) method. The TB measurements correlated well with the observed electron microscopic alterations. In vitro blood storage studies indicated loss of cell membrane during storage correlated with decreasing uptake of TB by the red cells. Regeneration of cellular ATP with adenosine did not always restore TB uptake by the cells.

Loss of red blood cell membrane either by exocytosis or endocytosis may occur during normal in vivo or in vitro ageing, and may be increased in pathological states or by the action of drugs.
Chronic Myeloproliferative Disorders: Improved Platelet Aggregation following Venesection
Authors: Boughton B.J.
Published: March 2008

Venesection of 10% of whole blood volume or plateletpheresis was performed in nine patients with chronic myeloproliferative disorders and in five normal control subjects. Before venesection, the patients showed impaired platelet aggregation in 33% of tests, most often in response to stimulation with 9 μmol adrenaline. After venesection, the platelet and megathrombocyte counts increased rapidly and excessively in most patients and platelet aggregation improved markedly. In some cases, spontaneous in vitro aggregation was seen at high platelet concentrations. In two patients impaired platelet aggregation with adrenaline was not corrected. The splenic platelet pool is thought to be the probable source of the new platelets.
Cell Membrane Enzymes II.
Authors: Kramers Mary T. C. , Catovsky D. , Foa R.
Published: March 2008

SUMMARY The distribution of two cell membrane enzymes, alkaline phosphatase and alkaline phosphodiesterase I has been studied in normal and leukaemic lymphocytes. No reduction in the level of activity of either enzyme was found in the chronic or acute B‐ and T‐cell leukaemias. Alkaline phosphatase activity was elevated in the lymphocytes from T‐CLL, cord blood and tonsils and the blast cells from Null‐ALL. Alkaline phosphodiesterase was elevated in lymphocytes from cord blood and tonsils and the blast cells from Null‐ALL. As findings in Null‐ALL were based on only two cases, they need confirmation in a larger series. The significance of these results is discussed in relation to current theories of maturation and differentiation in the lymphoproliferative disorders.
A Comparison using Quantitative Enzyme Cytochemistry between Leucocyte Alkaline Phosphatase Levels in the Bone Marrow and Blood of the Rat
Authors: Willlams David M. , Lampert Irvin A. , Evans David J.
Published: March 2008

SUMMARY Leucocyte alkaline phosphatasc (LAP) levels have been compared in neutrophil polymorphs in bone marrow and blood in the rat, using a quantitative enzyme cytochemical technique. It has been shown that LAP levels are higher in bone marrow than blood, both in normal animals and those with experimentally‐induced local inflammatory lesions. In the latter group both bone marrow and blood LAP levels were higher than in controls; blood levels rose because of the outpouring of cells with moderately high LAP levels into the blood and marrow levels rose because only cells with very high LAP levels remained. The inverse relationship between rieutrophil age and alkaline phosphatase content, previously demonstrated in the peripheral blood of the rat, has also been shown to exist in the bone marrow.
Release of β‐Thromboglobulin from Human Platelets by Therapeutic Intensities of Ultrasound
Authors: Williams A. R. , Chater B. V. , Allen K. A. , Sherwood M. R. , Sanderson J. H.
Published: March 2008

SUMMARY The effects of therapeutic intensities of ultrasound on human platelets in whole blood were investigated by monitoring the release of the platelet specific protein β‐thromboglobulin (β‐TG). More β‐TG was released as the intensity of the ultrasound was increased and also as the driving frequency was decreased from 3.0 to 0.75 MHz. Some β‐TG was released at spatially‐averaged intensities as low as 0.6 W/cm2 at 0.75 MHz, a value significantly lower than that observed for the onset of aggregation of platelet rich plasma (obtained from the same volunteer) in the same exposure system.

Liberation of β‐TG by ultrasound was diminished but not abolished in the presence of inhibitors which rendered the platelets functionally inert. Our data suggests that β‐TG is liberated in two ways, firstly as a result of platelet disruption by cavitation, and subsequently by potent aggregating agents, liberated in parallel with β‐TG, inducing the physiological release reaction in adjacent platelets.

The low therapeutic intensities and short exposure times (30 s or less) necessary to liberate β‐TG from normal human platelets in vitro, suggests that patients with abnormally sensitive platelets and/or ‘hypercoagulable state’ could be at risk if subjected to high therapeutic intensities of ultrasound.
Demonstration of the Outer Surface of Freeze‐etched Normal Human Platelets: Correlation with Buoyant Density
Authors: Tan Henry K. , Harrison Maria , Corash Laurence
Published: March 2008

Summary. . The external surface of the normal human platelet shows clusters of spherical particles in a reticular pattern with smooth and regular surface membrane in adjacent areas. Labelling with cationic ferritin demonstrates a diffuse distribution of ferritin particles which stop at the fracture face of the intramembranous surface. The intramembranous surface is not labelled. Previously discrepant observations on the plasma membrane surface are probably due to different techniques of platelet preparation for freeze‐etch electron microscopy. Density‐dependent platelet subpopulations do not differ with respect to the ultrastructural features of their external surface and intramembranous portions of the plasma membrane. Based upon the relationship between platelet density and age, it appears that the ultrastructure of the normal platelet plasma membrane does not change with in vivo ageing.