bluuebunny/crossref_metadata_2025 huggingface dataset:
Ferritin and Sideroblastic Anaemias: Inhibition of Protein Synthesis by Protease Contaminants in Commercial Preparations of Ferritin
Authors: Freedman Michael L. , Cohen Howard S. , Rosman Judith , Forte Frank J.
Published: March 2008

Commercial preparations of ferritin inhibited reticulocyte‐lysate cell‐free protein synthesis and disaggregated polyribosomes to monoribosomes and ribosomal subunits. These effects were prevented by addition of reduced glutathione (GSH) to the incubation medium, but ferritin did not lower GSH concentration in the lysates. The more purified the ferritin preparation, the less inhibition of protein synthesis was observed. These data suggested that the effect was due to a contamination of the ferritin with proteolytic activity. In confirmation of this proposal we demonstrated that there was protease activity in both the 2 × and 5 × crystallized ferritin preparations, with 2.5 times greater activity in the 2 × preparation. The proteolytic activity in ferritin was inhibited by incubation with the protease inhibitor tosyl lysine chloromethyl ketone (TLCK). When an amount of trypsin equivalent to the protease activity of the ferritin was added to the incubation mixture, similar effects on protein synthesis and the ribosome‐polyribosome component were found. Both GSH and TLCK prevented these effects of trypsin. These data suggest that the previously reported effect of ferritin on reticulocyte cell‐free protein synthesis was due to contamination of the ferritin by a protease. It appears that ferritin does not play a direct role in the pathogenesis of sideroblastic anaemias.
A Hypothesis for the Increased Oxygen Affinity in Haemoglobin Malmö
Authors: Zak Solomon J. , Geller Gary R. , Rrivit William , Tukey David , Brimhall Bernadine , Jones Richard T. , Bunn H. Franklin , McCormack Michael
Published: March 2008

Summary.

Haemoglobin Malmöβ97HisGln, a high oxygen affinity haemoglobin which causes secondary erythrocytosis, is transmitted in an autosomal dominant manner. A hypothesis accounting for the high oxygen affinity, hyperbolic oxy‐haemoglobin dissociation curve, and the relatively normal Bohr effect is presented. The purified abnormal haemoglobin from the present family provided biochemical and functional data for this hypothesis based on the allosteric model proposed by Perutz. Experimental results support the formation of a chemical bond between the ‐SH proton of the β93 cysteine and the amide of oxygen of the substituted β97 glutamine as an explanation for the high oxygen affinity of haemoglobin Malmö.
Relationship between Paraprotein Polymerization and Clinical Features in IgA Myeloma
Authors: Roberts‐Thomson P. J. , Mason D. Y. , MacLennan I. C. M.
Published: March 2008

Summary.

The clinical manifestations of IgA multiple myeloma are usually not considered distinguishable from those of IgG myeloma despite the fact that IgA differs from IgG in several characteristics, particularly molecular size heterogeneity. The clinical and laboratory features of 25 patients with IgA myeloma seen during a 5 year period are presented. The degree of paraprotein polymerization was observed to vary greatly in these patients but remained chronologically constant in six individuals studied on several occasions over this period. The patients were divided into two groups on the basis of the degree of paraprotein polymerization. The first group comprised those patients in whom the IgA paraprotein was greater than 50% polymerized, whilst in the second group the paraprotein was predominantly monomeric. No clinical or pathological differences were seen between the ‘polymeric’ and ‘monomeric’ groups of myeloma apart from that directly attributable to the physicochemical effect of the paraprotein polymerization. Thus, five patients out of 11 of the ‘polymeric’ group had developed the hyperviscosity syndrome, whilst no patients in the ‘monomeric’ group had developed this complication. The concentration of the paraprotein during the course of the disease was comparable in both groups.

This syndrome is considered to be relatively common in IgA myeloma and adds to the morbidity and mortality of the disease. Its anticipation and treatment may improve the quality and survival of patients likely to develop this complication.
The Effect of Transfer Factor on Neutrophil Function in Chronic Mucocutaneous Candidiasis
Authors: Lawton J. W. M. , Costello Christine , Barclay G. R. , Urbaniak S. J. , Darg C. , Raeburn J. A. , Uttley W. S. , Kay A. B.
Published: March 2008

Summary.

Chronic mucocutaneous candidiasis with hypoparathyroidism in a 6‐year‐old boy is described. In addition to defects of in vivo and in vitro correlates of delayed‐type hypersensitivity to Candida albicans the child also had abnormalities of neutrophil function in terms of their capacity to respond by chemotaxis to a known attractant and to kill suspensions of C. albicans. Dialysable transfer factor was given on six occasions at intervals of between 26 and 45 days. Neutrophil chemotaxis (optimal conditions) was restored following each of the six injections, neutrophil chemotaxis (sub‐optimal conditions) following five of the six injections and candidicidal capacity following four of the six injections. The effects of transfer factor were transient requiring repeated injections. The Candida delayed‐type hypersensitivity skin test was restored to normal but lymphocyte transformation to Candida extract was not consistently positive following treatment. There was a slight clinical improvement following therapy. These abnormalities of neutrophil and lymphocyte function point to the complexity of chronic mucocutaneous candidiasis. The improvement in neutrophil chemotaxis and candidicidal capacity following treatment suggests that transfer factor may be a heterogeneous group of molecules, some of which affect granulocytes and restore defects in their function.
The Effect of Cytotoxic Drugs on Neutrophil Phagocytosis in Vitro and in Patients with Acute Myelogenous Leukaemia
Authors: Davies J. E. , Whittaker J. A. , Khurshid M.
Published: March 2008

Summary.

The in vitro effects of a range of concentrations of cyclophosphamide, doxorubicin, actinomycin D, cytarabine and methotrexate on neutrophil phagocytosis of C. albicans was studied. The reduction in phagocytic index (PI) was inversely proportional to the dilution of the drug and there was some inhibition of phagocytosis at all dilutions of all drugs. In patients with acute myelogenous leukaemia (AML), in vivo experiments showed that remission chemotherapy of doxorubicin or daunorubicin together with cytosine arabinoside increasingly inhibited phagocytosis over the period studied. The importance of these findings in the chemotherapy of malignant disease and the possible mode of action of cytotoxic drugs are discussed.
The Kenya Form of Hereditary Persistence of Fetal Haemoglobin: Structural Studies and Evidence for Homogeneous Distribution of Haemoglobin F using Fluorescent Anti‐haemoglobin F Antibodies
Authors: Nute P. E. , Wood W. G. , Stamatoyannopoulos G. , Olweny C. , Failkow P. J.
Published: March 2008

Summary.

Several members of a Ugandan family were heterozygous for the γβ fusion gene of Haemoglobin Kenya. Levels of Hb Kenya were significantly higher than those in subjects of previous reports, ranging from 20.68 to 23.35% of the total haemoglobin. The individuals had also 5–8% Hb F, consisting solely of α and Gγ chains. Investigation of the distribution of Hb F among the red cells of Hb Kenya heterozygotes, using monospecific antibodies absorbed against pure Hb Kenya and rendered fluorescent by conjugation with fluorescein isothiocyanate, showed the presence of fetal haemoglobin in all red cells. The data suggest that the phenotype of the Hb Kenya trait resembles that of the Gγ form of hereditary persistence of fetal haemoglobin rather than that of thalassaemia.
Heterozygous Beta Thalassaemia of Unusual Severity
Authors: Friedman Sh. , ÖZsoylu S. , Luddy R. , Schwartz E.
Published: March 2008

Summary.

The proband of each of three families of Northern European or Italian extraction had an unusual form of heterozygous β‐thalassaemia, confirmed by haem‐atological, genetic and peripheral blood globin synthesis studies. The unusual severity of this disorder was indicated by chronic haemolysis leading to splenectomy and cholecystectomy, by numerous nucleated red cells and reticulocytes in the peripheral blood, and by leg ulcers in one family. The diversity of clinical expression in many family members with heterozygous β‐thalassaemia was striking. Bone marrow examination in the probands showed numerous large inclusion bodies of the type usually found only in thalassaemia major. In addition, there was unbalanced globin synthesis in the bone marrow, in contrast to the more balanced synthesis found in asymptomatic β‐thalassaemia trait. The amount of newly synthesized α‐chain found in the free δ‐chain pool was markedly elevated. The unbalanced globin synthesis and δ‐chain inclusions in the bone marrow cells suggest that the severity of the disorder in these patients may be due to the inability of their red cell precursors to fully compensate for the thalassaemic defect or to remove excess δ‐chains. The diversity of clinical expression suggests the influence of undefined acquired or genetic factors on the expression of β‐thalassaemia in these families.
The Pattern of Fetal Haemoglobin Disappearance after Birth
Authors: Colombo B. , Kim B. , Atencio R. Perez , Molina C. , Terrenato L.
Published: March 2008

Summary.

Haemoglobin F (Hb F) levels were determined in 209 full‐term newborn babies or infants of different ages ranging from birth to 11 months. A follow‐up study of the disappearance of Hb F after birth was carried out on 25 premature babies; they were followed periodically from birth until 8 months. The results obtained in both samples show that Hb F levels remain constant after birth for periods varying from about 15 d in at term babies to about 40 d in premature babies; a linear decrease follows in both cases. The initial plateau is a finding contrary to what has been reported. A possible model for the phenomenon is discussed in terms of haemoglobin genes and ontogenetic differentiation.
Mouse Red‐Cell Rosettes in B‐Lymphoproliferative Disorders
Authors: Catovsky D. , Cherchi Maria , Okos A. , Hegde U. , Galton D. A. G.
Published: March 2008

Summary. A high proportion of peripheral‐blood lymphocytes formed spontaneous rosettes with mouse red cells in 22 out of 23 cases of chronic lymphocytic leukaemia (CLL); the proportion was significantly higher than in 19 cases of other B‐lymphoproliferative disorders (non‐CLL group) and in 19 normal controls. Intermediate findings were obtained in 10 cases of ‘hairy’ cell leukaemia. Blast cells from various types of acute leukaemia did not bind mouse red cells. Pre‐treatment of the lymphocytes with neuraminidase led to a significant increase in the proportion of rosettes in CLL only. This test may prove useful in distinguishing CLL from other B‐lymphoproliferative disorders, particularly prolymphocytic leukaemia.
A Familial Abnormality of Circulating Vitamin B12 Binding Proteins: Occurrence in a Family of High Serum Concentrations of Transcobalamin II
Authors: Kane S. P. , Hoffbrand A. V. , Allen R. H. , Neale G.
Published: March 2008

Summary. A family is described in which two members (a father and daughter), both with quiescent ulcerative colitis, had abnormally high serum concentrations of a vitamin B12 binding protein. This protein had the molecular weight of transcobalamin II on gel filtration, and behaved like transcobalamin II with respect to its elution from DE‐23 cellulose, its inhibition at acid pH, its absorption by uncoated charcoal, its binding by anti‐TC II antibodies, and its ability to transfer vitamin B12 to transformed lymphocytes. Its plasma clearance and tissue distribution when injected into rabbits was indistinguishable from that of transcobalamin II from normal subjects. It migrated on electrophoresis in the βγ region.

This is the first case report of related subjects in whom high serum concentrations of transcobalamin II have been observed.
The Effect of Some Anticonvulsant Drugs on Depletion of Folate in Rats on a Vitamin B12‐Deficient Diet
Authors: Williams D. L. , Spray G. H.
Published: March 2008

Summary. Rats fed on vitamin B12‐deficient or vitamin B12‐supplemented diets and treated with phenobarbitone by intraperitoneal injection for 5 d showed significant increases in the activity of glutamate formiminotransferase in liver. The only significant depletion in liver folate activity was in vitamin B12‐supplemented rats that were starved for 48 h. When rats were given the same diets, with phenobarbitone and diphenylhydantoin added, for 12 weeks or more in two separate experiments, significant increases in transferase activity were found only in the livers of animals fed on the deficient diet. However, there was significant depletion of liver folate in animals taking the supplemented diet.
Rheological Properties of Red Cells in Haemoglobin Köln Disease
Authors: Tillmann W. , Labitzke N. , Schröter W.
Published: March 2008

Summary. The rheological properties of erythrocytes of four patients with haemoglobin Köln (Hb Köln) disease were studied. Filtration of erythrocytes through polycarbonate sieves with a pore diameter of 5 μm and viscosity measurements of erythrocytes suspensions with a PCV of 80% were carried out. The rheological properties of erythrocytes of two of the patients were severely altered. In both patients an increased haemoglobin attachment to erythrocyte membranes resulting in a decreased filtration rate of erythrocytes was found. One of these cases had been splenectomized some years before. About half of the erythrocytes of this patient contained large Heinz bodies. Erythrocytes of this patient showed a decreased filtration rate and an increased viscosity. Moreover, erythrocytes of healthy adults containing Heinz bodies after incubation with acetylphenylhydrazine showed a decreased filtration rate as well as an increased viscosity. Membranes of erythrocytes of the other patients contained haemoglobin in an amount within the normal range of haemoglobin content of membranes of healthy adults. Erythrocytes of these patients showed normal rheological properties. The haemolytic process in these patients was only mild. We suggest that the amount of total haemoglobin attached to the erythrocyte membrane corresponds to the percentage of the unstable Hb Köln present in the erythrocytes of the particular patient.
Erythrocyte Membrane Modification in Malignant Diseases of Myeloid and Lymphoreticular Tissues
Authors: Bird G. W. G. , Wingham June , Pippard M. J. , Hoult J. G. , Melikian V.
Published: March 2008

Summary. Tn polyagglutination (persistent mixed‐field polyagglutination) occurring in a patient with an acute myelocytic leukaemia, is described. The association of this RBC membrane change, thought to be due to somatic mutation at stem cell level, with a myeloproliferative disorder, has not been previously reported.
Erythrocyte Membrane Modification in Malignant Disease of Myeloid and Lymphoreticular Tissues
Authors: Bird G. W. G. , Wingham June , Chester G. H. , Kidd P. , Payne R. W.
Published: March 2008

Summary. A case of acute erythroleukaemia is described. The patient's RBC, which at first appeared to be a mixture of groups B and O, were shown in fact to be a mixture of normal B and very weak B.
Severe Hereditary Haemolytic Anaemia in Dogs Treated by Marrow Transplantation
Authors: Weiden Paul L. , Storb Rainer , Graham Theodore C. , Schroeder Maria‐Louise
Published: March 2008

Summary. Severe hereditary haemolytic anaemia related to pyruvate kinase deficiency occurs in Basenji dogs homozygous for this autosomal recessive defect. In the current study, three anaemic dogs were treated by total body irradiation and marrow transplantation from non‐anaemic histocompatible littermates with resultant complete correction of their haemolytic anaemia. The possible use of marrow transplantation for life‐threatening haemolytic anaemias in man is discussed.
Control of Haemopoietic Stem Cell Proliferation by Cells in DNA Synthesis
Authors: Nečas E. , Neuwirt J.
Published: March 2008

Summary. It has been demonstrated that for the slowly proliferating population of the haemopoietic pluripotent stem cells (CFUs) the response after damage by hydroxyurea to cells synthesizing DNA differs from that after damage by colchicine to cells entering mitosis. The killing of DNA synthesizing cells elicits increased proliferation in the CFUs population. From this it has been inferred that cells in the S phase may inhibit the entry of nonproliferating G0 cells into the cell cycle and in this way control cellular proliferation.
Lymphoid Cell Dependent (K‐Cell) Lysis of Human Erythrocytes Sensitized with Rhesus Alloantibodies
Authors: Urbaniak S. J.
Published: March 2008

Summary. An in vitro homologous system using human Rhesus alloantibodies and target erythrocytes labelled with 51Cr has been used to demonstrate the ability of normal peripheral blood lymphoid cells to lyse antibody‐coated human red cells. The results obtained suggest that this type of mechanism may be relevant to certain haemolytic diseases in man.
Intercellular Contacts between Erythroid Precursors in the Bone Marrow in Dyserythropoiesis
Authors: Frisch B. , Lewis S. M. , Swan M.
Published: March 2008

Summary. The ultrastructure of the cellular interfaces between erythroid precursors has been studied in both congenital and acquired dyserythropoiesis. The types of cell‐to‐cell contacts found included highly convoluted interdigitating septate‐like junctions as well as apparent confluence of the cellular membranes of adjacent erythroid cells. Such findings are not characteristic of the intercellular relationships found in the normal erythroblastic islands. The erythroid plasma membrane modifications are possibly related to the changes in the plasma membranes of erythroid cells known to occur in dyserythropoiesis and their presence may well contribute to the ineffective erythropoiesis with intramedullary cell destruction which characterizes many dyserythropoietic states.
The Use of Chang Cells Cultured in Vitro to Evaluate Potential Iron Chelating Drugs
Authors: White G. P. , Jacobs A. , Grady R. W. , Cerami A.
Published: March 2008

Summary. A number of iron chelating agents, consisting largely of hydroxamic acid and benzoic acid derivatives, have been studied in an in vitro Chang cell culture system to determine their effect on cellular iron uptake, ferritin synthesis and the incorporation of iron into ferritin. The results have been compared with those of a previous study in which iron balance was determined in hypertransfused rats. Both techniques appear to be of value in screening new iron chelating agents for potential therapeutic use in patients with iron overload.
The Uptake of Ferric Iron by Rat Liver Ferritin in Vivo and in Vitro
Authors: Hoy T. G. , Harrison Pauline M.
Published: March 2008

Summary. The incorporation of ferric iron labelled with 59Fe into rat liver ferritin has been studied in whole animals, into liver homogenate and into purified protein. Uptake of Fe3+ into purified rat liver ferritin followed a pattern similar to that with horse spleen ferritin given Fe2+ and an oxidant. The distributions of iron incorporated as a function of molecular iron content obtained in vivo resembled the in vitro patterns for iron contents above 500 Fe atoms/molecule and times after injection of up to 12 h. At larger intervals a maximum label moved to molecules of highest iron content as the molecules accumulated more iron. The apparently reduced uptake of injected 59Fe into molecules of low iron content might be due either to the chase of cold iron through an existing iron pool or the presence of functionally different ferritins at more than one anatomic site within the cell.
Acquired von Willebrand Syndrome with Inhibitors Both to Factor VIII Clotting Activity and Ristocetin‐Induced Platelet Aggregation
Authors: Stableforth P. , Tamagnini G. L. , Dormandy Katharine M.
Published: March 2008

Summary. A case of acquired von Willebrand's syndrome (vWs) is described which appeared to be due to antibodies directed against factor VIII clotting activity (FVIIIC), factor VIII‐related antigen (FVIIIRAg) and von Willebrand factor. The antibodies directed against FVIIIRAg was demonstrated by the inhibitory effect of a platelet eluate on Ristocetin‐induced aggregation of normal platelets. This effect was not shown by the patient's platelet‐poor plasma alone, nor could it be demonstrated in platelet eluates from 13 other patients who had antibodies to FVIIIC but in whom there was no evidence of an acquired vWs.
Sheehan's Syndrome with Complete Bone Marrow Aplasia: Long‐term Results of Substitution Therapy with Hormones
Authors: Ferrari E. , Ascari E. , Bossolo P. A. , Barosi G.
Published: March 2008

Summary. A case of Sheehan's syndrome with pancytopenia and bone marrow aplasia is presented. The diagnosis was made 6 years after an ante‐partum haemorrhage. The presenting feature was an anaemia unresponsive to usual therapy. Hormonal therapy alone (cortisone and thyroid extract with triiodothyronin, oestrogen and progestogen given sequentially) produced full haematological recovery, which has continued for 2 years since the treatment was begun.
An Epidemiological Study of the Haemostatic and Other Effects of Oral Contraceptives
Authors: MEADE T. W. , BROZOVIć MILICA , CHAKRABARTI R. , HOWARTH D. J. , NORTH W. R. S. , STIRLING YVONNE
Published: March 2008

Summary. Factors V, VII and VIII (each determined by biological assay), fibrinogen, platelet count and adhesiveness, and fibrinolytic activity were measured in 234 white pre‐menopausal women, of whom 57 (24%) were on oral contraceptives and 177 (76%) were not. Cholesterol, triglyceride and blood pressure levels were also recorded. In 20 of the women on oral contraceptives, and in an age‐matched group of 20 who were not, prothrombin, factor X, antithrombin III and α2‐macroglobulin levels were determined, and factors VII and VIII were also measured immunologically. For the majority of the variables studied, the differences between those using and not using oral contraceptives were greater in younger than older women; in the case of factor VII (biological assay) and fibrinogen, the differences between the regression slopes on age were statistically significant, and mean values were substantially higher in those on oral contraceptives. There was also a significant difference between regression slopes on age for cholesterol. Mean levels of prothrombin, factors VII (immunological assay) and X, triglycerides and blood pressure were significantly higher, and mean levels of antithrombin III significantly lower, in those on oral contraceptives compared with those not. Overall, fibrinolytic activity was significantly higher in the women on oral contraceptives; this difference was, however, almost entirely due to the greatly increased fibrinolytic activity of the non‐smokers on oral contraceptives, activity in the smokers on oral contraceptives being similar to that of the women not on these preparations. There were no significant differences in mean platelet count or adhesiveness, or in haemoglobin, packed cell volume, uric acid and blood sugar levels. Among the women on oral contraceptives, there was a significant negative correlation between factor VIII and fibrinolytic activity; this was largely due to five women all of blood groups A and B, in whom, besides high factor‐VIII levels and poor fibrinolytic activity, other variables (e.g. fibrinogen) were raised in a direction that might be expected to favour thrombogenesis. It is possible that it is those women whose fibrinolytic activity does not increase in order to compensate for the effects of oral contraceptives on clotting factors, lipids and blood pressure, who are at special risk of thromboembolic episodes. The differential effects of oral contraceptives by age must be borne in mind in evaluating the effects of these preparations on the haemostatic and lipid systems.
Evidence for a Splenic Release Factor of Platelets in Chronic Blood Loss Plasma of Rabbits
Authors: WEINTRAUB A. H. , KHAN I. , KARPATKIN S.
Published: March 2008

Summary. Rabbits subjected to chronic blood loss with iron supplementation raised their platelet count and megathrombocyte number 1.7x and 2.1 x above baseline, respectively. In similarly treated splenectomized animals, no significant response was obtained. When chronic blood loss plasma was injected into recipient animals there was a rise in platelet count and megathrombocyte number of 1.8 x and 3.4 x respectively compared to animals injected with control plasma. In similarly treated splenectomized animals no such rise was obtained; neither was there a rise in platelet count or megathrombocyte number in intact recipient animals when chronic blood loss plasma was obtained from splenectomized animals. It is concluded that the thrombocytosis of chronic blood loss requires the presence of an intact spleen. The data suggest the presence of a release factor which requires the spleen for its elaboration as well as expression.
Identification of Human Mononuclear Cells by Anti‐Monocyte Serum
Authors: STUART A. E. , YOUNG GILLIAN A. , GRANT P. F.
Published: March 2008

Summary. An antiserum to human leukaemic monocytes was raised in rabbits. Adsorption with human thymocytes and chronic lymphatic leukaemia cells rendered the antiserum specific for cells of the human myeloid and monocytic cell series. Additional adsorption with granulocytes left a weak, but specific, activity for monocytes. The cells in normal peripheral blood with which the antiserum reacts by an immunoperoxidase technique have typical monocyte morphology. Cells with typical lymphocyte morphology do not react with the antiserum, but a few cells with intermediate morphology were also stained by the antiserum. Using the antiserum as a marker, the precursor cells of the monocytic and myeloid cell series were traced in the bone marrow.
Effect of Pyridoxal 5′‐Phosphate on the Oxygen Affinity of Human Erythrocytes
Authors: MAEDA NOBUJI , TAKAHASHI KENJI , AONO KENJI , SHIGA TAKESHI
Published: March 2008

Summary. Pyridoxal 5′‐phosphate (PLP), an allosteric effector for the oxygenation of haemoglobin, was incorporated readily into erythrocytes and disappeared from them by simple passive diffusion. The disappearance of PLP from the cells was accelerated by the generation of 2,3‐DPG in a medium of inosine, pyruvate and phosphate. The oxygen dissociation curve measured at an extracellular pH of 7.4 demonstrated that PLP incorporated into the cells also lowered the oxygen affinity and that PLP functionally compensated for a metabolically reduced 2,3‐DPG. However, the dependency of the oxygen affinity on the intracellular PLP concentration showed a different pattern from that observed for 2,3‐DPG. On the other hand, the lowering of intracellular pH by organic phosphates accumulated in the cells was much larger with PLP than with 2,3‐DPG. The peculiar relationship between the oxygen affinity of erythrocytes and the intracellular PLP concentration is discussed in detail. The present study may offer a new prospect for the preservation of blood with a normal function.
Ultrastructure of Sickling and Unsickling in Time‐Lapse Studies
Authors: HAHN J. A. , MESSER M. J. , BRADLEY T. B.
Published: March 2008

Summary. The denser subpopulation of erythrocytes from patients with sickle cell anaemia was deoxygenated to a pO2 of 4.7 kPa or reoxygenated to a pO2 of 12 kPa with a continuous‐flow apparatus. Samples were collected into modified Karnovsky's fixative at intervals between 0.5 and 15 s. The earliest event after deoxygenation was aggregation of haemoglobin followed by the formation of fibres of 160–200 Å diameter. These polymers were always randomly distributed in a loose network. A highly ordered, close packing of fibres characteristic of the nematic liquid crystal was not achieved within 15 s. Depolymerization involved a shortening of fibres followed by aggregation similar to that observed early in the polymerization process and prior to the return to the unperturbed state. Irreversibly sickled cells were the first to demonstrate polymers following deoxygenation and the last to lose polymers after reoxygenation. Polymerization of the haemoglobin preceded the appearance of the sickled deformity of reversibly sickled cells and, following reoxygenation, the return to the discoid shape lagged behind the disappearance of polymers. These studies, carried out under physiologic conditions, have demonstrated intracellular changes during time intervals that correspond to the normal venous and arterial circulation that may contribute to the pathophysiology of sickling disorders.
Studies with the Folate Binding Protein in Chronic Granulocytic Leukaemia Cells: I. SYNTHESIS AND RELEASE OF BINDER BY CELLS IN SHORT‐TERM CULTURE
Authors: COSTA MARIA DA , ROTHENBERG SHELDON P.
Published: March 2008

Summary. Chronic granulocytic leukaemia (CGL) cells which contained a high concentration of unsaturated folate binding protein were incubated in suspension culture for a period of 5 h. Cell samples were periodically assayed for binder and these demonstrated active synthesis which was inhibited by puromycin, cyclo‐heximide, N‐ethylmaleimide, and by incubation at 4°, but not by actinomycin D.

Folate binding activity could also be demonstrated in the culture medium and this increased with the duration of incubation. This release of binder was inhibited by culturing the cells at 4° and by the addition of N‐ethylmaleimide, but not by actinomycin D, puromycin, or cycloheximide.

When the pre‐ and post‐culture cell lysates were saturated with tritiated folic acid ([3H]PteGlu) and subjected to chromatography on DEAE‐agarose, approximately half of the bound folate eluted with 0.001 M phosphate buffer at pH 6.0 and the other half eluted with 0.2 M buffer at pH 7.2. The culture medium and plasma from this patient with CGL as well as serum from two normal subjects saturated with [3H]PteGlu and similarly chromatographed contained primarily the acidic binder and much less of the binder eluting with the low molarity buffer.

Since a folate binding protein immunochemically similar to the binder in CGL cells has been identified in the serum of non‐leukaemic subjects, these experiments suggest that the source of circulating folate binding protein may be the immature granulocyte.
Studies on Calcium Transport and Calcium‐dependent Adenosine Triphosphatase Activity of Erythrocyte Membranes in Hereditary Spherocytosis
Authors: ZAIL S. S. , HOEK ANNE K. VAN DEN
Published: March 2008

Summary. Evidence has been recently presented of a relative deficiency of Ca2+‐dependent adenosine triphosphatase activity of erythrocyte membranes obtained from patients with hereditary spherocytosis. We have sought to confirm these findings by measuring calcium efflux from intact erythrocytes of patients with hereditary spherocytosis, as well as erythrocyte calcium concentrations, but find both these parameters to be normal. Ca2+‐dependent adenosine triphosphatase activity, as well as Ca2+‐dependent membrane phosphorylation was also not found to be deficient in erythrocyte membranes from subjects with hereditary spherocytosis. These studies do not support the postulate that an accumulation of calcium affects the deformability of erythrocytes and their subsequent destruction in the spleen.
Differential Expression of Cell Surface Binding Sites for Cholera Toxin in Acute and Chronic Leukaemias
Authors: REVESZ T. , GREAVES M. F. , CAPELLARO D. , MURRAY R. K.
Published: March 2008

Summary. Binding of purified cholera toxin to cell surface receptors has been visualized by an indirect immunofluorescence procedure. Normal nucleated cells from blood, bone marrow and lymphoid tissues, express these receptors with the possible exception of erythroid precursors. Cells from patients with chronic lymphoid or myeloid leukaemias have a normal receptor expression but acute leukaemic cells showed a marked deficiency in cholera toxin binding. Insertion of purified Gm1 ganglioside into membranes of acute leukaemic cells provided cellular binding sites for the toxin.
Megakaryocytes and the Heterogeneity of Circulating Platelets
Authors: PENINGTON D. G. , STREATFIELD K. , ROXBURGH A. E.
Published: March 2008

Summary. Megakaryocytes mature to the point of cytoplasmic disintegration in three principal ploidy classes: 8n, 16n and 32n. Cells of each of these ploidy classes have been identified, using both microdensitometry and measurement of cell volume and submitted to morphometric analysis. Mature megakaryocytes of the three ploidy classes have been shown to differ in the concentration of cytoplasmic constituents which would be expected to relate to the buoyant density of their platelet progeny. Density separated platelets have been similarly analysed. Light platelets correspond with the 32n megakaryocytes and are more liberally endowed with surface connected canalicular system than the progeny of the common 16n megakaryocytes; it is proposed that they have functional characteristics related to this finding. Dense platelets, which are larger in size, correspond with 8n megakaryocytes and show a greater content of granules and mitochondria than platelets of average density. These platelets most probably show specialized function relating to release of granule constituents.

Fragments of cytoplasm released from megakaryocytes represent one form of ‘megathrombocyte’equated by others with newly formed platelets. The differences in structure between these fragments and circulating platelets are emphasized; each such fragment must undergo further disintegration into a number of platelets. It is suggested that the heterogeneity of circulating platelets with respect to both size and density stems from the origin of platelets of varying density from the different populations of megakaryocyte and their release in the form of large cytoplasmic fragments rather than as platelets.
Benzene Inhibition of in Vitro Rabbit Reticulocyte Haem Synthesis at Delta Aminolaevulinic Acid Synthetase: Reversal of Benzene Toxicity by Pyridoxine
Authors: Freedman Michael L. , Wildman Joseph M. , Rosman Judith , Eisen Jane , Greenblatt David R.
Published: March 2008

Benzene (0.113 M) inhibited haem and protein synthesis in rabbit reticulocytes. This inhibition of haem synthesis was found when L‐2‐[14C]‐glycine was used as the radioactive precursor. However, when 4‐[14C]Δ‐aminolaevulinic acid (ALA) was used, there was no significant inhibition. Since ALA measures the haem synthetic pathway beyond the enzyme Δ‐aminolaevulinic acid synthetase (ALA synthetase), these results suggest that benzene inhibits haem synthesis at or before ALA synthetase. This was confirmed by demonstrating that 1 mM ALA both protected against and reversed the benzene inhibition of reticulocyte protein synthesis. In addition, 1 mM pyridoxine both protected against and reversed the benzene inhibition of reticulocyte haem and protein synthesis. These results indicate that benzene (or a metabolite) either competes with pyridoxal phosphate at ALA synthetase or competes with pyridoxine for pyridoxal phosphokinase.

These results are discussed in terms of their implications for the possible roles of ALA synthetase and the haemin‐controlled repressor in benzene‐induced aplastic anaemia.
Platelet Antibodies in Thrombocytopenic Patients
Authors: Hegde U. M. , Gordon‐smith E. C. , Worlledge Sheila
Published: March 2008

Platelet antibodies either bound to the surface of platelets or free in the serum were sought in patients who had low platelet counts for a variety of reasons. They were detected by finding excess IgG on the surface of washed platelets either directly or after incubation of the serum with normal platelets. The technique used was a modification of that described recently (Dixon et al, 1975) in which the greater the amount of anti‐IgG consumed by the reaction with platelets the less the subsequent lysis of sheep red cells coated with IgG. This test could be calibrated by adding known quantities of IgG to the antisera and thus the amount of bound IgG could be measured. Platelets from normal donors and those with thrombocytopenia due to non‐immunological causes such as aplastic anaemia or acute leukaemia were found to have 15–70 ng IgG/107 platelets (mean 53 ng). 37 out of 38 thrombocytopenic patients in whom immune destruction of platelets was suspected were found to have excess IgG on their platelets ranging from 70 to 720 ng/107 (mean 297 ng, P < 0.001) and there was a significant inverse correlation between this amount and the platelet count (r= 0.85, P < 0.001). Antibody in the serum was found in 14 of 22 patients with ‘idiopathic’thrombocytopenic purpura (ITP), three of four patients with underlying lymphoma and in all five cases of systemic lupus erythematosus (SLE). Four non‐thrombocytopenic patients with autoimmune haemolytic anaemia (AIHA) due to IgG on the red cells were also studied and were shown to have no increase in platelet‐bound IgG. Our results confirm the work of Dixon et al (1975) that platelet antibody as excess IgG can be readily detected on the surface of platelets in patients with immune thrombocytopenia. The clinical implications of these findings are discussed.
Effects of Cephalothin and Penicillin G on Platelet Function in Vitro
Authors: Cazenave Jean‐Pierre , Guccione Maria A. , Packham Marian A. , Mustard J. Fraser
Published: March 2008

High concentrations of cephalothin or penicillin G inhibit a number of the functions of human or rabbit platelets in citrated platelet‐rich plasma (PRP) and in suspensions of washed platelets. The reactions shown to be inhibited are: ADP‐induced shape change and the primary and secondary phases of aggregation and release induced by ADP or adrenaline in human citrated PRP; release and aggregation of washed human platelets exposed to collagen, thrombin, vasopressin, or the ionophore A23,187; aggregation of washed human platelets exposed to phytohaemagglutinin from Phaseolus vulgaris (PHA) or polylysine; release induced by concanavalin A or PHA in suspensions of washed platelets from rabbits; platelet adherence to a collagen‐coated surface or to the damaged intimal surface of the rabbit aorta; platelet factor 3 availability; lysis of rabbit platelets by an antiserum directed against them; and clot retraction. Neither antibiotic affected serotonin‐induced aggregation; a high concentration of cephalothin slightly inhibited the initial rate of serotonin uptake. Penicilloic acid showed about half the inhibitory effect of penicillin G on ADP‐induced aggregation. In citrated human platelet‐rich plasma, ampicillin and oxacillin inhibited ADP‐induced aggregation to the same extent as similar concentrations of penicillin G; in suspensions of washed platelets, however, ampicillin was less inhibitory than penicillin G or oxacillin. Platelet ultrastructure, assessed by transmission electron microscopy, was not visibly altered. Evidence that the antibiotics become bound to platelets is the finding that platelets incubated with the antibiotics and resuspended in fresh media showed less response to aggregating agents compared with control platelets. Penicillin G and related antibiotics may be inhibitory because they coat the platelet surface. Their effects on platelet functions are probably responsible for excessive bleeding and increased bleeding times observed in patients and volunteers receiving high doses of these antibiotics.
Acquired Dysfibrinogenaemia in Acute and Chronic Liver Disease
Authors: Lane D. A. , Scully M. F. , Thomas D. P. , Kakkar V. V. , Woolf I. L. , Williams Roger
Published: March 2008

Plasma from patients with both acute and chronic liver disease has been examined for evidence of acquired dysfibrinogenaemia, using electrophoretic methods and coagulation tests. An examination of isolated fibrins upon SDS polyacryamide gel electrophoresis failed to demonstrate any molecular or structural defect associated with the polypeptide chains of the patients’fibrinogen or fibrinogen derivatives produced by thrombin or plasmin. However, purified fibrin monomers isolated from plasma using both Reptilase and thrombin exhibited delayed polymerization rates and the occurrence of acquired dysfibrinogenaemia in liver disease is therefore confirmed.
Pathophysiological Changes in Serum Erythropoiesis Stimulating Activity
Authors: Napier J. A. F. , Dunn C. D. R. , Ford T. W. , Price V.
Published: March 2008

The mouse fetal liver cell bioassay has been used to study serum levels of erythropoiesis stimulating activity (ESA) in patients with a variety of haematological disturbances. The results indicate that this assay system provides a quantitative measurement of ESA, the concentration of which varies predictably in a manner which is consistent with it having a function as an in vivo regulator of erythropoiesis. Dose‐response curves for serum ESA show highly significant parallelism with those obtained from sheep plasma erythropoietin and the International Reference Preparation of human urinary erythropoietin.
Isolation and Characterization of an Actin‐like Protein from Membranes of Human Red Cells
Authors: Ohnishi Tsuyoshi
Published: March 2008

The existence of an actin‐like protein in human red‐cell membranes has been confirmed. The protein was extracted from acetone‐treated ghosts and purified by (NH4)2SO4 fractionation. The protein undergoes G‐F transformation and forms filaments in the presence of O.I. M KCl. The filaments can be ‘decorated’by muscle heavy meromyosin. The protein has the same molecular weight as muscle actin and interacts with muscle myosin. All these properties show that the protein closely resembles muscle actin.
Depression of the Platelet Count after Inoculation of Mice with L1210 or L5178Y Cells
Authors: Hacker M. , Roberts D. , Jackson C.
Published: March 2008

The inoculation of L1210 or L5178Y leukaemia cells decreased the platelet count of the recipient mouse before extensive infiltration of marrow was expected by either tumour line. The decrease was more pronounced after intravenous inoculation of L1210 leukaemia than after intraperitoneal inoculation. Inoculation of L5178Y cells by both routes caused an initial decrease but the count recovered to 80% of normal before becoming markedly depressed prior to death of the host. Implantation of diffusion chambers containing L1210 cells also decreased the platelet count, which later returned to normal.
Abnormal Platelet Function in Chediak‐Higashi Syndrome
Authors: Jordison Boxer Grace , Holmsen Holm , Robkin Linda , Bang Nils U. , Boxer Laurence A. , Baehner Robert L.
Published: March 2008

Platelets in an infant with Chediak‐Higashi (C‐H) syndrome without bleeding manifestations and not in the accelerated phase showed abnormal function consistent with storage pool disorder as shown by abnormal aggregation, decreased storage capacity and release of [14C]5‐HT, low endogenous 5‐HT, reduced ATP and ADP with an increased ATP/ADP ratio, increased specific radioactivity of ADP after [14C]adenine labelling, decreased release of adenine nucleotides after stimulation, impaired secretion of acid hydrolases despite normal stores, and decreased calcium content. Incorporation of [14C]adenine into metabolic pool adenine nucleotides was normal. Nucleotide conversion to hypoxanthine in stimulated platelets was mildly impaired. Platelet cyclic‐AMP (c‐AMP) was initially elevated, but even when c‐AMP returned to normal levels after ascorbate treatment, platelet function was not improved. Elevated intracellular c‐AMP was not solely responsible for the abnormal platelet function.
Binding of Factor VIII to Platelets in the Presence of Ristocetin
Authors: Zucker Marjorie B. , Kim Sook‐ja , Mcpherson Jean , Grant Robert A.
Published: March 2008

Ristocetin agglutinates platelets in platelet‐rich plasma (PRP) containing factor VIII‐related von Willebrand factor (WF). When the clumps were separated from the supernatant and resuspended in buffer, the platelets dispersed if the buffer was free of ristocetin and the PRP had been treated with aspirin or EDTA to prevent the platelet release reaction. Binding to platelets was determined by measuring WF (ristocetin cofactor assay), VIIIR‐antigen (AG, by radioimmunoassay), and coagulant activity (C) in the initial plasma, the supernatant remaining after removing the clumps formed by ristocetin, and the eluate produced after resuspending the clumped platelets in buffer. No activity was bound to platelets in the absence of ristocetin. After agglutinating platelets in PRP with ristocetin, WF, AG and C activities in the supernatants were about 65% of the initial plasma values, and in the eluates about 9%. Formalin‐fixed washed platelets resuspended in 1 in 3 plasma, and platelets in PRP diluted 1 in 3 also agglutinated when shaken with ristocetin. There was no difference between results with fixed and unfixed platelets. In one series of experiments, the supernatants had about 60% of the initial WF and AG activities; since these activities were the same, they may measure the same substance. In a later series, WF and C were compared; in shaken samples the supernatants had 39% of the initial WF activity and 56% of the initial C activity, and in unshaken samples the supernatants had 3% WF and 29% C. The significantly lower values for C binding suggest that this activity is located on a different molecule from WF‐AG and that the molecules are more readily separated in diluted than in undiluted plasma. Activity in the eluates was inversely proportional to that in the supernatants although the initial activity was never completely recovered. WF and C binding increased with platelet number and ristocetin concentration. Platelets exposed to ADP before fixation showed less agglutination than control fixed platelets and bound less WF. Fixed platelets incubated for 15 min with 30 μg trypsin/ml and washed, or platelets from a patient with the Bernard‐Soulier syndrome failed to agglutinate and bound virtually no WF, AG or C. We conclude that WF, AG and C reversibly bind to fixed or unfixed platelets in the presence of ristocetin, that binding is similar in undiluted plasma but greater for WF and AG than C in plasma diluted 1 in 3, and that ADP and trypsin alter binding, probably by affecting a platelet receptor.
The Correlation of Cold Agglutinin Titrations in Saline and Albumin with Haemolytic Anaemia
Authors: Garratty George , Petz Lawrence D. , Hoops J. K.
Published: March 2008

Cold agglutinin syndrome (CAS) is usually associated with IgM cold agglutinins with titres exceeding 1000 at 4deg;C and a thermal amplitude of 30‐32deg;C. Occasionally patients are encountered who although having clinical and laboratory findings compatible with CAS do not have the characteristic serological findings. Thirty‐two patients with a positive direct antiglobulin test due to complement sensitization were studied. Thirty‐one of these patients had cold agglutinin titres greater than 64. Twenty‐eight had haemolytic anaemia, including one patient with a cold agglutinin titre of only 8 against saline‐suspended red cells. 53.6% of sera from patients with haemolytic anaemia reacted at 30deg;C and 7.1% at 37deg;C when albumin was not present, whereas in the presence of albumin all of the sera reacted at 30deg;C and 67.9% reacted at 37deg;C. None of the four patients without haemolytic anaemia reacted at 30deg;C or 37deg;C in the presence of albumin, even though one serum reacted to a titre of 1280 at 4deg;C. Cold agglutinin titres and thermal amplitudes in the presence of bovine albumin were found to correlate better with haemolytic anaemia than reactions without albumin. If bovine albumin is utilized in compatibility testing, multiple cold autoabsorptions may be necessary before alloantibody activity at 37deg;C can be excluded.