bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence that Washed Human Platelets Possess Factor‐X Activator Activity
Authors: Semeraro N. , Vermylen J.
Published: March 2008

Summary. Human platelets, washed by repeated albumin density gradient centrifugation or by gel filtration, aggregate upon addition of normal human serum and calcium chloride, due to generation of thrombin from the small amount of residual prothrombin present in normal serum. The rate of thrombin formation is dependent on the factor V provided by the platelets as shown by a marked decrease in formation when platelets from a subject with congenital factor‐V deficiency are used instead of normal platelets. When phospholipid, factor V (bovine serum absorbed with barium sulphate), calcium chloride and fibrinogen were added to serum, no thrombin formation was observed, indicating that serum itself was devoid of factor Xa. In addition, when washed platelets and calcium chloride were mixed with a factor‐X deficient serum or with a highly purified prothrombin preparation devoid of factor X, hardly any thrombin generation occurred, indicating that the washed platelets did not supply factor Xa. Therefore activated factor X is probably generated in the mixture containing washed platelets, normal serum and calcium chloride. Activation of factor X via the intrinsic pathway is unlikely since (a) washed platelets and normal serum are devoid of factor VIII, and (b) washed platelets and/or serum obtained from subjects with factor‐VIII or factor‐IX deficiency or with factor‐VIII antibodies behaved in the same way as normal platelets or serum in the test system. Activation of factor X via the extrinsic pathway is also unlikely since (a) serum and platelets from a congenitally factor‐VII deficient subject behaved normally in the test system, and (b) rapid thrombin generation occurred when serum was replaced by purified prothrombin and purified factor X devoid of factor VII. These findings indicate that washed human platelets possess factor‐X activator activity. Platelet factor 3 is not strongly implicated in the generation of thrombin in this test system since prostaglandin El, which reduces its availability, had no influence on the reaction.
The Assessment of Red Cell Survival in Normal Subjects and in Patients with Haemoly tic Disorders and Ineffective Erythropoiesis using the Radioiron Occupancy Method
Authors: Hutcheon A. W. , Horton P. W. , Orr J. S. , Dagg J. H.
Published: March 2008

A direct method for measuring red cell lifespan in vivo using the radioiron occupancy method (Dagg et al, 1972) has been applied to eight normal subjects. The mean red cell lifespan was 116 d with a range of 104‐124 d.

To establish the method clinically in the presence of haemolysis and ineffective erythropoiesis, 22 patients with haemolytic disease and six patients with megaloblastic and sideroblastic anaemia were studied. All 22 patients with haemolytic anaemia had shortening of the red cell lifespan, with a range from 62 to 10 d; the results were compared with red cell lifespan derived from simultaneous radiochromium studies (Bentley et al, 1974). A close agreement between the two methods was obtained (r = 0.87; P<0.00I).

To assess the validity of the method in the presence of ineffective erythropoiesis, double isotope studies were also carried out in three patients with megaloblastic anaemia and diree with sideroblastic anaemia. Close agreement was again obtained between lifespan measurements obtained from radioiron occupancy data and those derived from radiochromium studies, suggesting that the presence of significant ineffective erythropoiesis does not invalidate the method.

The theoretical considerations involved in the application of the radioiron occupancy method to haemolytic states are discussed.
The Exchangeable Splenic Platelet Pool in Response to Selective Adrenergic Beta‐1‐Receptor Blockade
Authors: Kutti Jack , Fredén Krister , Melberg Per‐Erik , Lundborg Per
Published: March 2008

The aim of the present work was to investigate the effect of selective beta‐I‐blockade on the exchangeable splenic platelet pool (ESPP). Therefore, 50 mg of metoprolol (a selective beta‐i‐receptor blocking agent) was given by mouth to three groups of subjects: (1)15 healthy volunteers, (2) five asplenic subjects, and (3) 10 patients with different myeloproliferative disorders (MPD) with and without splenomegaly. The platelet count was determined 90, 150, 210, 270 and 330 min after the ingestion of the drug.

In the group of healthy controls a significant increase (P< 0.005) in the platelet count occurred and amounted to about 10% over baseline. The average peak value was reached at 150 min and the elevation in platelet count was maintained more than 4 h. An increase in the platelet count was also induced in patients with MPD, but the mean for the peak value only reached borderline significance (o. 10 P 0.05). In the group of asplenic subjects no change in the platelet count occurred.

It is concluded that acute oral administration of metoprolol causes a significant release of platelets from the ESPP. This platelet release is, however, not enhanced if the ESPP is enlarged.
Double Heterozygosity for Two Unstable Haemoglobins: Hb Sydney (β67[E11] Val→Ala) and Hb Coventry (β141[H19] Leu Deleted)
Authors: Casey R. , Kynoch P. A. M. , Lang A. , Lehmann H. , Nozari G. , Shinton N. K.
Published: March 2008

A 7‐year‐old English girl was found to have a lobar pneumonia with a marked haemolytic anaemia. Routine electrophoresis revealed no abnormal haemoglobin but, as anticipated, an unstable haemoglobin fraction readily formed in haemolysates on routine in vitro instability tests. From the subsequent structural and biosynthetic studies it was concluded that the propositus' red cells contained, in addition to Hbs A, A2 and F, two unstable haemoglobins with abnormalities in the primary structure of their non α‐chains: Hb Sydney and Hb Coventry. The first has an amino acid substitution Val→Ala at position β67 (E11), while the other, Hb Coventry, is a new variant with a non α‐chain which resembles the βA‐chain except that the leucine residue at position β141(H19) is deleted. This suggests that, instead of the normal complement of two β‐chain genes, the propositus' genome has three, i.e. βA‐, βSydney‐ and βCoventry‐chain genes. Evidence is presented from which it can be concluded that the non α‐chain of Hb Coventry, whilst being structurally a β‐chain variant is, in fact, a βδ fusion chain variant with 140β‐ and 5δ‐chain residues. The oxygen dissociation curve of the propositus showed a reduced affinity at the upper part of the curve, a feature which she shared with a straightforward heterozygote for Hb Sydney, and a slight shift to the left in the lower part, a feature which she shared with her father who possessed Hb Coventry.
Differential Blood Cell Separation using a High Gradient Magnetic Field
Authors: Paul F. , Roath S. , Melville D.
Published: March 2008

A technique for the separation of erythrocytes from whole blood is described which exploits the magnetic property of haemoglobin in the reduced state. The technique is characterized by the use of a filter consisting of a cylinder, containing stainless steel wire mesh, placed between the jaws of an electro magnet. When activated, the electromagnet induces a magnetic field gradient in the vicinity of each of the constituent wires, sufficient to attract and trap erythrocytes in suspension. The number of erythrocytes captured varies with the applied field (0–1.4 Tesla in these experiments) and flow rate (1.9–12.9 × 10−4 m s−1). The capture process does not cause haemolysis or observable surface damage to the erythrocytes and neither leucocytes nor platelets are retained by the filter.
Intracellular λ Light Chain Inclusions in Chronic Lymphocytic Leukaemia
Authors: McCann S. R. , Whelan A. , Greally J.
Published: March 2008

A case of chronic lymphocytic leukaemia (CLL) with intracytoplasmic crystalline inclusions in peripheral blood lymphocytes is presented. The inclusions were identified as crystals of lambda (Δ) light chain and were present in bone marrow derived (B‐cells) lymphocytes. The occurrence of light chain crystals in CLL may reflect a more primitive defect in immunoglobulin (Ig) synthesis, intracellular transport or secretion than has previously been reported.
Lack of Effect of Prednisone Administration on Bleeding Time and Platelet Function of Normal Subjects
Authors: Thong K. L. , Mant Michael J. , Grace Michael G.
Published: March 2008

The effect of 80 mg prednisone given orally for 2 d on normal and post‐aspirin bleeding times and platelet function has been studied in a randomized, multiple cross‐over, double‐blind controlled trial in 12 normal volunteers. Mean template bleeding times were 6.6 min (placebo/placebo), 5.9 min (prednisone/placebo), 10.0 min (placebo/aspirin) and 8.7 min (prednisone/aspirin). The shortening after prednisone administration was not statistically significant. Prednisone had no effect on platelet glass bead retention nor on platelet aggregation by collagen, adrenalin and adenosine diphosphate. Thus conventional clinical doses of prednisone did not impair platelet function and did not enhance primary haemostatis in normal subjects as measured by the bleeding time.
International Collaborative Study of Assay of Anti‐D (Anti‐Rho) Immunoglobulin
Authors: Bangham D. R. , Kirkwood T. B. L. , Wybrow G. , Hughes‐Jones N. C. , Gunson H. H.
Published: March 2008

An international collaborative study of anti‐D assays has been carried out by 21 laboratories in 11 countries. Samples of anti‐D immunoglobulin assayed in this study included two dilutions of a preparation used in clinical trials to determine a dose–protection relation, a national standard, commercial clinical preparations and the proposed international reference preparation in coded ampoules.

Manual, automated haemagglutination and isotope labelling methods all gave similar relative potencies. Several of these estimates were significantly (P=0.95) heterogeneous and some modifications to improve assay design and procedure are suggested.

The coded preparation was shown to be stable and suitable for comparative assays. It was estimated to contain 60 μg of anti‐D IgG immunoglobulin per ampoule, and 150 i.u./ampoule when assayed against the International Standard for Incomplete Anti‐D Blood Typing Serum. Thus for this preparation 1 μg of IgG anti‐D immunoglobulin ≡ 2.5 i.u. anti‐D antibody. At its 28th meeting the Expert Committee on Biological Standardization of WHO established the preparation 68/419 as the International Reference Preparation of Anti‐D Immunoglobulin and assigned to it a potency of 150 i.u. per ampoule. The Preparation has been widely used (with a nominal content of 60 μg of IgG anti‐D immunoglobulin) for control of clinical preparations.
The Effects of Glucocorticoids on Cultured Human Endothelial Cells
Authors: Maca R. D. , Fry G. L. , Hoak J. C.
Published: March 2008

The effects of hydrocortisone, dexamethasone and prednisone on the morphology, replication, DNA synthesis, cell protein content and protein synthesis of cultured, human endothelial cells were evaluated. After culturing the cells with these glucocorticoids for 24–48 h, the cells covered a greater portion of the culture surface area. The mean surface area of the individual endothelial cell treated with glucocorticoids was 1.53 times greater than that of the untreated control endothelial cell. When compared with controls, the endothelial cover provided by the cells treated with glucocorticoids was more extensive and in many instances covered the entire culture surface. The change in morphology was associated with an increase in protein synthesis and protein content of the cells without an increase in DNA synthesis or cellular replication. Dexamethasone was approximately 10‐fold more effective than hydrocortisone, while prednisone was the least effective. Aldosterone, DOCA, testosterone, progesterone, oestradiol and oestriol were ineffective. These studies indicate that glucocorticoids can alter the morphology and biochemistry of cultured endothelial cells and may have implications for the effects of steroids in the treatment of thrombocytopenic states and vascular disorders in man.
The Role of Adherence to Human Mononuclear Phagocytes in the Destruction of Red Cells Sensitized with Non‐Complement Binding IgG Antibodies
Authors: van der Meulen F. W. , van der Hart Mia , Fleer A. , von dem Borne A. E. G. Kr. , Engelfriet C. P. , van Loghem J. J.
Published: March 2008

In patients with IgG incomplete non‐complement binding warm autoantibodies, the subclass composition of the antibodies was studied in relation to the occurrence of increased haemolysis in vivo and the adherence of the patients red cells to peripheral blood monocytes (PBM) in vitro.

The presence of IgG3 autoantibodies was almost always accompanied by haemolytic anaemia, but the presence of IgG1 autoantibodies only in some patients but not in others. IgG2 and IgG4 autoantibodies were not associated with increased red cell destruction.

A relation identical to that between subclass composition and increased haemolysis was found between subclass composition and adherence of the patients erythrocytes to PBM and thus a strong correlation between positive adherence in vitro and increased red cell destruction in vivo.

These results support an important role of adherence to mononuclear phagocytic cells in the destruction of red cells sensitized with non‐complement binding IgG antibodies. Strong indications were found that IgG1 autoantibodies are of two kinds, only one of which causes adherence to phagocytes and thus increased red cell destruction.
Plateletpheresis by Discontinuous Centrifugation: Effect of Collecting Methods on the in Vitro Function of Platelets
Authors: Chao Francis C. , Tullis James L. , Tinch Robert J. , Conneely Gail S. , Baudanza Phyllis
Published: March 2008

The in vitro function of platelets collected by two different methods during centrifugal plateletpheresis was compared. The RBC method involves collecting platelets with red cells followed by a supplementary spin to remove them, whereas the no‐RBC method requires collecting platelets only from the buffy coat without red cells. Platelet response to adenosine diphosphate (ADP), epinephrine and collagen was slightly reduced in platelet‐rich plasma (PRP) prepared by no‐RBC technique and was markedly decreased in samples obtained by the RBC technique when compared to prepheresis controls. The decrease in platelet response to ADP, epinephrine and collagen was apparent in three testing systems: aggregation, release of serotonin and reptilase clot retraction. Both plasma and platelets appeared to be affected by the pheresis procedure. Platelet preparations obtained by both RBC and no‐RBC techniques showed an increase of platelet factor 3 activity and an enhancement of aggregation, release of serotonin and clot retraction induced by thrombin as compared to prepheresis controls. Postpheresis platelet‐poor plasma contains platelet membrane fragments which exhibit a high platelet factor 3 activity. The results showed that the RBC method, although providing a higher platelet yield, caused more qualitative alterations in platelets than in those obtained by no‐RBC method, and that both methods of collecting platelets activated the procoagulant activity of platelets.
A Simple Immunofluorescence Test for the Detection of Platelet Antibodies
Authors: von dem Borne A. E. G. Kr. , Verheugt F. W. A. , Oosterhof F. , von Riesz E. , de la Rivière A. Brutel , Engelfriet C. P.
Published: March 2008

Immunofluorescence tests on platelets have always been hampered by nonspecific fluorescence caused by non‐immunological binding of plasma proteins to the platelet membrane. It was found that this could be easily overcome by fixation of the cells with paraformaldehyde (PFA). By using PFA‐fixed platelets, a simple method for the detection of platelet antibodies, the platelet suspension immunofluorescence test (PSIFT) was developed.

PFA fixation did not alter or inactivate the platelet antigens tested. Platelet‐reactive antibodies detected specifically with the PSIFT included platelet‐specific agglutinins of the IgM class, non‐agglutinating platelet‐specific antibodies of the IgG class, drug‐dependent platelet antibodies, HLA antibodies, as well as anti‐A and anti‐B antibodies. The sensitivity of the new test was satisfactory, as was its reproducibility. Measurement of platelet immunofluorescence was possible in a continuous flow microfluorometer, making in principle, quantitation of platelet antibodies and antigens possible.
Paroxysmal Nocturnal Haemoglobinuria in Thailand with Special Reference to an Association with Aplastic Anaemia
Authors: Kruatrachue M. , Wasi P. , Na‐Nakorn S.
Published: March 2008

Eighty‐five cases of PNH in Thailand were analysed, with emphasis on the comparison with European series and on an association with aplastic anaemia. Compared with European series, two points emerge: (1) the disease in Thai affects individuals of younger age group with a tendency to male preponderance; (2) the incidence of arterial and venous thrombosis is relatively rare. In association with aplastic anaemia, two main categories of PNH patients, are described, which differ in their clinical and laboratory citeria.
Autoimmune Granulocytopenia: the Detection of Granulocyte Autoantibodies with the Immunofluorescence Test
Authors: Verheugt F. W. A. , von dem Borne A. E. G. Kr. , van Noord‐Bokhorst J. C. , Engelfriet C. P.
Published: March 2008

Neutropenia may be caused by neutrophil autoantibodies. The detection of such antibodies has always been difficult. Recently, we developed a sensitive indirect immunofluorescence technique applicable to granulocytes which proved to be of value in the detection of granulocyte alloantibodies. We have now used this method to investigate the serum and cells of 29 patients with idiopathic or secondary neutropenia.

In four patients neutrophil‐antigen‐specific autoantibodies were detected in the serum and the patient's own granulocytes showed direct fluorescence. Furthermore, differences in the immunoglobulin composition and the temperature of optimal activity of the autoantibodies were found.

Direct fluorescence was also demonstrated with the granulocytes from five other neutropenic patients and with the granulocytes from five non‐neutropenic patients mainly with infectious disease. However, no granulocyte antibodies could be eluted or shown to be present in the serum. This indicates that a positive direct granulocyte fluorescence test may not be considered as proof that autoantibodies are present.
Erythropoiesis and Mean Red‐Cell Lifespan in Normal Subjects and in Patients with the Anaemia of Active Rheumatoid Arthritis
Authors: Dinant H. J. , de Maat C. E. M.
Published: March 2008

Recently developed ferrokinetic methods offer a tool to measure effective and ineffective erythropoiesis and mean red‐cell lifespan (Ricketts et al, 1975). We have used this tool to investigate erythropoiesis in normal subjects and in patients with the anaemia of active rheumatoid arthritis. In normal subjects the results are comparable with the results published by Cavill et al (1977). In patients with the anaemia of active rheumatoid arthritis there appears to be a total and an effective red‐cell production as in the normal subjects. The ineffective erythropoiesis in the patients is increased and the produced red cells have a shortened mean lifespan in the circulation. The increased ineffective erythropoiesis is probably due to inadequate supply of iron to the marrow and the shortened mean red‐cell lifespan to an extra‐corpuscular haemolytic factor. The impaired marrow response to the anaemia of active rheumatoid arthritis has been confirmed.
Acceleration of Methaemoglobin Reduction by Riboflavin in Human Erythrocytes
Authors: Matsuki Takasumi , Yubisui Toshitsugu , Tomoda Akio , Yoneyama Yoshimasa , Takeshita Masazumi , Hirano Masami , Kobayashi Kenichi , Tani Yoshio
Published: March 2008

The effect of riboflavin on nitrite treated erythrocytes from normal subjects and patients with hereditary methaemoglobinaemia due to the deficiency of NADH‐cytochrome b5 reductase was studied in the presence of glucose, 2‐deoxy‐d‐glucose or lactate. When glucose or 2‐deoxy‐d‐glucose was used as a substrate for these erythrocytes, the rate of methaemoglobin reduction in these cells was accelerated more than two‐fold in the presence of riboflavin. The acceleration was dependent on the concentration of riboflavin and was suppressed by the addition of atebrin. The stimulative effect of riboflavin was, however, not observed when lactate was used in place of glucose or 2‐deoxy‐d‐glucose. On the basis of these results, the acceleration of methaemoglobin reduction by riboflavin was considered to be due to the activation of NADPH‐flavin reductase (Yubisui et al, 1977) in erythrocytes by the reagent. The availability of riboflavin for patients with methaemoglobinaemia due to the deficiency of NADH‐cytochrome b5 reductase and for those with toxic methaemoglobinaemia is discussed in relation to methaemoglobin reducing systems in erythrocytes.
A New Type of Congenital Dyserythropoietic Anaemia
Authors: Sansone G.
Published: March 2008

This report concerns a 6‐year‐old child with severe dyseythropoietic anaemia and splenomegaly, apparently present since the first months of life. Striking anisopoikilocytosis was observed in the blood smear. The bone marrow showed marked erythroblastic hyperplasia with dyserythropoiesis. Ineffective erythropoiesis was demonstrated by ferrokinetic studies. Ultrastructurally erythroblasts appeared grossly abnormal. The clinical course was progressively worsening, necessitating repeated transfusions. The patient's father, also affected by a chronic anaemia of moderate degree since childhood, had a peripheral picture of anisopoikilocytosis, a shortened life span of the erythrocyte, and in his bone marrow an erythroblastic hyperplasia with many atypical erythroblasts. His condition deteriorated because of persistent jaundice, biliary cholelithiasis, fibrosis and haemosiderosis of the liver. The clinical course, the pattern of the genetical transmission, the peculiar features of the erythroblasts disclosed by light and by electron microscope studies suggest that these cases represent a new type of congenital dyserythropoietic anaemia.
Evaluation of Toluidine Blue for Measuring Erythrocyte Membrane Loss during in Vivo Ageing
Authors: Greenwalt Tibor J. , Lau Francis O.
Published: March 2008

A simple method using a cationic dye, toluidine blue (TB), to quantify changes of red cell membrane area has been developed and tested for its validity. After incubating a glucose‐depleted red cell suspension with a fixed quantity of TB at 37°C for 10 min, the remaining TB was measured spectrophotometrically at 640 nm. Using this technique, we were able to show differences in TB uptake by populations of young and old red cells. The exact mechanism for TB uptake by the red cells is not clear. Treatment of the cells with bromelin, papain and trypsin reduced the uptake of TB, but neuraminidase and ficin had little or no effect. No inhibition of TB removal by red cells was observed using heparin, d‐glucose, glucuronic acid, or n‐acetylglucosamine.
Defective Binding of Thrombin to Platelets in Myeloid Leukaemia
Authors: Ganguly P. , Sutherland S. B. , Bradford H. R.
Published: March 2008

Platelets from patients with myeloid leukaemia showed reduced aggregation with collagen or thrombin. These platelets also had a lower capacity to bind thrombin. This lower thrombin binding is due to a decrease in the total quantity of receptors available and not because of a change in the affinity. In the presence of the patients’plasma, the aggregation behaviour of normal platelets induced by thrombin as well as the clotting time of fibrinogen remained unchanged. The results suggest that the platelet dysfunction in myeloid leukaemia is partially due to a membrane defect involving the thrombin receptors which leads to an impaired induction of the initial stimulation.
The Surface Morphology of Mitogen‐Stimulated Human Peripheral Blood Lymphocytes
Authors: Newell D. G. , Roath S.
Published: March 2008

The changes occurring in surface morphology during the transformation of normal peripheral blood lymphocytes by phytohaemagglutinin (PHA) are described and the surface ultrastructure of the PHA‐induced blasts is compared with that of pokeweed mitogen (PWM)‐ and rabbit anti‐β2‐microglobulin antiserum‐induced blasts. Both mitogen‐specific and non‐specific changes were observed and their possible relationship to the activation of lymphocyte subpopulations is discussed. Similar surface characteristics found in various tissue lymphoid cells are also described.
A Sensitive Test Demonstrating Lupus Anticoagulant and its Behavioural Patterns
Authors: Exner T. , Rickard K. A. , Kronenberg H.
Published: March 2008

SUMMARY The kaolin clotting time of platelet poor plasma was used as a sensitive test for detecting the lupus anticoagulant in mixtures of normal and patients' plasmas. Platelets were found to decrease the anticoagulant effect of a typical lupus inhibitor. Thus, high sensitivity in this test system was achieved by ensuring low platelet coilcentrations and omitting platelet lipid substitute. In 17 patients with disseminated lupus erythematosus (DLE), 12 had detectable inhibitor by this method, more than would be detected with routine coagulation tests. Mixing patterns were of four distinct types, representing three different modes of anticoagulant behaviour. The pattern (type 3) of plasma mixtures giving longer kaolin clotting times than the individual components could be reproduced in vitro by adding trace amounts of crude thrombin or platelet fragments to a more typical lupus anticoagulant‐containing plasma: formation of such a mixing pattern by the plasma of a patient with DLE may therefore indicate activation of the coagulation pathway. Six patients with idopathic thrombocytopenic purpura (ITP) had no detectable inhibitor indicating that anti‐platelet antibodies behave differently from the lupus anticoagulant.
Erythrocyte Calcium Abnormalities and the Clinical Severity of Sickling Disorders
Authors: Steinberg Martin H. , Eaton John W. , Berger Elaine , Coleman Mary B. , Oelshlegel Fred J.
Published: March 2008

Summary. We studied erythrocyte calcium levels and uptake in a group of patients with sickle haemoglobinopathies of different clinical severity in an attempt to relate these measurements to the production of irreversibly sickled cells and disease severity. Erythrocyte calcium levels were measured by atomic absorption spectroscopy and calcium uptake by isotopic means. In sickle cell anaemia, erythrocyte calcium content was elevated and the uptake of isotopic calcium increased under both oxygenated and deoxygenated conditions. There was a direct correlation between the numbers of irreversibly sickled cells and calcium uptake and an inverse relationship between calcium uptake and red cell potassium level. The clinical course of disease was milder in patients with high fetal haemoglobin levels, but there was no relationship between clinical course and calcium levels, calcium flux or irreversibly sickled cells. Our observations suggest that calcium accumulation and irreversibly sickled cell formation are related processes. The absence of good correlation between various biochemical and clinical parameters emphasizes the complexity of factors which modify the clinical course of this disorder.
Haem Biosynthesis in Rheumatoid Disease
Authors: Campbell B. C. , Rennie N. , Thompson G. G. , Moore M. R. , Goldberg A.
Published: March 2008

Summary.The activities in blood of six enzymes of the haem biosynthetic pathway have been determined in 12 patients with rheumatoid disease, six of whom were anaemic. The porphyrin and porphyrin‐precursor intermediary products of haem biosynthesis were also determined in blood, urine and faeces. No significant differences were found between anaemic and non‐anaemic subjects. Failure of δ‐aminolaevulinate synthase activity to increase in response to anaemia may be the nature of the marrow unresponsiveness suggested as one factor in the causation of the anaemia. Normal ferrochelatase activity and normal concentrations of free protoporphyrin support the view that iron is effectively unavailable although present in normal amounts. Coproporphyrinogen oxidase activity was significantly depressed.
Congenital Dyserythropoietic Anaemia Type III: an Electron Microscopic Study
Authors: Björkstén Bengt , Holmgren Gösta , And Göran Roos , Stenling Roger
Published: March 2008

Summary

The morphological features of erythroblasts in congenital dyserthropoietic anaemia (CDA) type III were studied by electron microscopy. Typical findings included clefts and blebs within the nuclear region, autolytic areas within cytoplasm, iron‐filled mitochondria and myelin figures. The findings resembled those reported in other dyserythropoietic anaemias particularly in CDA type I; the main morphologic features which distinguished the two types were lack of spongy appearance of the chromatin, lack of cytoplasmic organelles within the nuclear region and intact nuclear envelope in CDA type III.
Calcium‐induced Damage of Haemoglobin SS and Normal Erythrocytes
Authors: Eaton John W. , Berger Elaine , White James G. , Jacob Harry S.
Published: March 2008

Summary

An ionophore specific for divalent cations has been used to load normal erythrocytes and erythrocytes from patients with sickle cell anaemia (Hb SS disease), with small amounts of calcium. Such calcium accumulation leads to decreased cellular water, potassium, adenosine triphosphate (ATP), and osmotic fragility, all characteristics of irreversibly sickled cells (ISCs). In addition, calcium loading of Hb SS, but not normal, erythrocytes causes a marked decrease of haemoglobin oxygen affinity; another, and specific, hallmark of ISCs. Ionophore‐induced accumulation of calcium by deoxygenated Hb SS erythrocytes also leads to temporary retention of sickled shape following reoxygenation, despite the absence of detectable intracellular haemoglobin S fibres. All these effects require calcium in the incubation medium and support the idea that increased intracellular calcium is important in the formation of ISCs in patients with Hb SS disease.
Thrombin Activation of Factor VIII
Authors: Rick Margaret E. , Hoyer Leon W.
Published: March 2008

Summary

The current experiments examine the reaction between purified human α‐thrombin and purified human factor VIII and compare this with the reaction between α‐thrombin and the low molecular weight factor VIII procoagulant activity obtained by high ionic strength dissociation. The reaction patterns of both procoagulants are similar, demonstrating an initial increase in factor VIII activity followed by a decay of procoagulant activity. The extent of activation which is observed in the initial phase decreases with lower temperatures and with lower thrombin concentrations. A pseudo‐first order relationship is demonstrated for the activation phase.

The labile factor VIII procoagulant activity produced by the initial action of thrombin appears to be intrinsically unstable, since the addition of hirudin or diisopropylfluorophosphate does not prevent the subsequent decay of the procoagulant activity. The similar activation and decay patterns of purified factor VIII and the dissociated low molecular weight factor VIII procoagulant support the concept that the low molecular weight procoagulant itself represents the functional coagulant moiety of the factor VIII complex.
Granulocyte Transfusions: Evaluation of Factors Influencing Results and a Comparison of Filtration and Intermittent Centrifugation Leukapheresis
Authors: Aisner Joseph , Schiffer Charles A. , Wiernik Peter H.
Published: March 2008

Summary

The clinical factors influencing the results of granulocyte transfusion were evaluated, and the incidence of reactions following transfusion of granulocytes obtained by filtration and intermittent centrifugation leukapheresis was compared. Thirty‐seven patients received 195 evaluable transfusions (99 filtration and 96 centrifugation) for 45 infectious episodes. The mean yields were 22.2 × 109 granulocytes for filtration and 8.3 × 109 granulocytes for centrifugation using non‐stimulated donors. Prospectively, 58 transfusions (29 filtration and 29 centrifugation) were transfused to 17 matched donor—recipient pairs and 12 (40%) moderate or severe reactions occurred after filtration transfusions while two (7%) moderate reactions occurred after centrifugation transfusions. Overall 36% of filtration transfusions and 3 % of centrifugation transfusions were associated with reactions. Among 18 infectious episodes which improved, five patients improved only because of granulocyte transfusions. Among 11 episodes which stabilized, six stabilized only because of transfusions. Sixteen episodes progressed. The five patients who improved and the six who stabilized only because of transfusions, received more granulocytes than those who progressed. Responses were seen following transfusion of granulocytes collected by either filtration along or both methods. Only three patients clearly progressed and they received centrifugation granulocytes alone suggesting that the dose of granulocytes derived from intermittent centrifugation may have been suboptimal.
A Simple and Efficient Method of Labelling Red Cells with 99mTc for Determination of Red Cell Volume
Authors: And Jennifer Jones , Mollison P. L.
Published: March 2008

Summary

It has been shown by others that treatment of red cells with very small amounts of tin in the form of stannous citrate or stannous pyrophosphate before incubation with 99mTc results in the subsequent binding of almost all the added technetium and that when the labelled cells are injected into the circulation the rate of elution of 99mTc is less than when cells are labelled by first adding 99mTc, then tin. Because of the instability of stannous salts in solution, methods have previously been described for the freeze‐drying of very small aliquots of tin in ‘kits’, specially designed for the labelling of red cells with 99mTc. The present paper confirms the advantage of‘pre‐tinning’in labelling red cells with 99mTc and describes a method for which no special kit is needed and in which even smaller amounts of tin than have been used previously give optimal results. A dilution of stannous chloride which provides the requisite very low concentration of tin is prepared by a simple two‐stage procedure. Since uptake of 99mTc is about 95%, only a single wash is necessary after labelling. Estimates of red cell volume based on a single sample at 10 or 20 min after an injection of labelled cells, uncorrected for loss of label, agree very closely with those obtained with 51Cr. Loss of label in the first hour after injection is only about 4% which is significantly less than that observed with a post‐tinning procedure. Because of the much lower rate of toxicity of 99mTc compared with 51Cr, 99mTc‐labelled red cells should be used for estimating red cell volume whenever practicable.
Erythrocyte Catabolism in the Inflammatory Peritoneal Monocyte
Authors: Kleber E. E. , Lynch S. R. , Skikne B. , Torrance J. D. , Bothwell T. H. , Charlton R. W.
Published: March 2008

Summary. Inflammatory peritoneal exudates were prepared in rats by the intraperitoneal injection of a solution of either casein or methaemalbumin, and 85–95% of the cells harvested from the peritoneal cavities were mononuclear cells. These cells actively phagocytosed antibody‐coated rat erythrocytes containing haemoglobin labelled in vivo with 59Fe. Erythrocyte phagocytosis occurred rapidly: when the ratio of erythrocytes to monocytes was 1: 8, a mean of 61.7 (± SD 12.5)% of the radioactivity was present in the monocytes within 2 h. The uptake of radioiron introduced into the incubation system in the form of haemoglobin bound to haptoglobin, haem bound to haemopexin, or iron bound to transferrin or ferritin proceeded much more slowly. Monocytes harvested after cither casein or methaemalbumin injection were capable of degrading haemoglobin and transforming up to half the radioiron originally present in haemoglobin into ferritin. A greater proportion of the haemoglobin was degraded by the ‘methaemalbumin monocytes’. Haemoglobin catabolism was accompanied by the formation of approximately equimolar quantities of bilirubin. Most of the radioiron released into the supernatant medium was in the form of either ferritin or haem bound to haemopexin. The behaviour of inflammatory peritoneal monocytes therefore appears to be different from that of liver and spleen reticuloendothelial cells, which release most of the iron derived from erythrocyte haemoglobin catabolism in a form which is available to transferrin. The results of this study may provide an explanation for the increase in plasma haem concentration and the methaemalbuminacmia which has been observed after haemorrhage into the tissues in situations in which there is no intravascular haemolysis and the haptoglobin binding capacity of haemoglobin has not been exceeded
Heparin Pharmacokinetics: Increased Requirements in Pulmonary Embolism
Authors: Simon Toby L. , Hyers Thomas M. , Gaston Joseph P. , Harker Laurence A.
Published: March 2008

Summary.Heparin disappearance after injection and plasma levels during continuous infusion were studied in normal subjects and patients with thrombophlebitis, pulmonary embolism, renal failure, and liver failure. Heparin removal in normal subjects after 75 u/kg was nearly linear with a clearance of 0.64 ml/min/kg, SD±0.11. Clearance varied inversely with dose. Heparin clearance in pulmonary embolism (0.80 ml/min/kg ±0.23) was significantly accelerated compared both to normals (P< 0.005) and to thrombophlebitis patients (0.55 ml/min/kg± 0.19, P<0.01); the disappearance was more curvilinear in thrombophlebitis and pulmonary embolism than in normal subjects (P<0.025). Continuous infusion heparin requirements were greater in pulmonary embolism than in thrombophlebitis, in accordance with pharmacokinetic predictions. The pattern and rate of disappearance in renal disease was similar to normal subjects; in liver disease clearance was accelerated (0.86 ml/min/kg±0.28) and disappearance curvilinear. Because of accelerated clearance, the initial dose of heparin in pulmonary embolism should be greater (25 u/kg/h) than in thrombophlebitis (10‐15 u/kg/h). Variability within patient groups necessitates some laboratory control of dosage.
The Influence of Red Blood Cells on the Effects of Aspirin or Sulphinpyrazone on Platelet Adherence to Damaged Rabbit Aorta
Authors: Davies J. A. , Essien E. , Cazenave J.‐P. , Kinlough‐Rathbone R. L. , Gent M. , Mustard J. F.
Published: March 2008

Summary. The effects of acetylsalicylic acid (ASA; aspirin) or sulphinpyrazone (SP) on the adherence of washed rabbit platelets to the subendothelial surface of an everted aorta mounted on a probe or to the subendothelial surface of a rabbit aorta attached to a perfusion apparatus were examined. ASA had no effect on platelet adherence to a damaged aorta perfused with a suspension of washed platelets in a medium containing 10% red blood cells (RBC); SP was slightly inhibitory at high concentration. When damaged rabbit aortae were everted on a probe and rotated in a suspension of washed platelets to which RBC were added to a packed cell volume of 10%, both ASA and SP inhibited platelet adherence to the damaged vessel wall. When the PCV was 40%, ASA was not inhibitory and SP reduced platelet adherence only at very high concentrations. It is therefore unlikely that, at the concentrations achieved in man, SP exerts an effect on platelet adherence. The different effects of ASA and SP on platelet survival do not appear attributable to their effects on platelet adherence.
Modulation of Transferrin Receptors in Bone Marrow Cells by Changes in Lipid Fluidity
Authors: Muller Claude , Shinitzky Meir
Published: March 2008

Summary. The hypothesis that modulation of transferrin receptors during haematopoiesis is mediated by changes in the lipid fluidity of the cell membranes was tested in this study with bone marrow cells. Binding conditions were first established, under which internalization of fluorescently‐labelled transferrin was reduced to a minimum during the binding assays. Cholesterol depletion, which was achieved by a mild physiological treatment, and which increased the membrane‐lipid fluidity, resulted in a substantial increase in the average number of the available transferrin receptors per bone marrow cell. Cholesterol enrichment mediated a converse effect. These findings correlate well with the changes observed in the availability of transferrin receptors and membrane microviscosity during differentiation of erythroid cells. In line with the notion of passive modulation, it is proposed that the transferrin receptor is a cross‐membrane protein with a substantial portion facing the cytoplasm.
The Low Ionic Strength Reaction of Human Blood: Relationship between the Binding of Serum Immunoglobulin and Complement to Red Blood Cells and Surface Charge of the Cells
Authors: Hsu T. C. S. , Steinberg J. , Le Doux R. , Sawitsky A.
Published: March 2008

Summary. Using the sucrose haemolysis reaction of Hartmann & Jenkins (1966) as a basic model, the low ionic strength reaction (LISR) of human blood was studied to determine: (1) serum Ig uptake by RBC with saline elution and 125I‐IgG uptake, and (2) complement fixation (CF) to RBC with lysis of PNH cells and C3/C4 antiglobulin haemagglutination (AH) of normal cells.

The saline eluates were found to contain IgG and IgM with traces of IgA; their pH optima for the uptake by RBC were 6.0±0.5, 5.5±0.5 and c 5.0 respectively. The ratio of bound IgG to IgM was linearly related to the uptake pH. Both C4 AH and lysis were found to be optimum at pH 6.0±7.5, whereas the maximum C3 AH was at pH 6.0±0.5. The LISR performed at a constant pH (6.1±0.1) showed that an increasing concentration of neuraminidase (VCN) used in pretreatment of RBC was associated with a decrease in both IgG uptake and CF activity. A maximum VCN effect reduced the Ig uptake to c 20% of normal and abolished almost all the CF activity. An impaired LISR to various degrees was also observed with RBC pretreated with ficin, papain, bromelin, trypsin or protamine, and RBC from two individuals of En(a–) type. Preincubation of serum at LIS with and without RBC resulted in respectively a ‘complete’ and partial consumption of C in the fluid phase. The latter was not enhanced or inhibited by the addition of VCN‐treated RBC for preincubation.

A hypothesis is proposed suggesting that in the LISR the Ig uptake by RBC is an electrostatic interaction of the oppositely charged RBC and Ig and the CF to RBC results from C activation by the cell‐bound IgG and IgM. In addition, a pH‐dependent inactivation of the cell‐bound C3 in the LISR is demonstrated.
Neonatal Erythrocyte Glutathione Peroxidase Deficiency as a Consequence of Selenium Imbalance during Pregnancy
Authors: Perona G. , Guidi G. C. , Piga A. , Cellerino R. , Milani G. , Colautti P. , Moschini G. , Stievano B. M.
Published: March 2008

Summary. The red blood cell (RBC) glutathione peroxidase (GSH‐Px) activity and routine haematological parameters were measured in 38 healthy north Italian full‐term pregnant women and in their newborn infants. In 31 pairs the serum selenium concentration was also measured. Data were compared with those of 20 normal adult controls (10 males and 10 females).

Newborn infants exhibited significantly lower RBC GSH‐Px activity and serum selenium concentrations than adult controls. Pregnant women had serum selenium values intermediate between those of adult female controls and their newborn infants.

In both the pregnant women and newborns the RBC GSH‐Px activity correlated with the level of selenium in serum which suggests that the neonatal RBC GSH‐Px deficiency may be partially due to insufficient availability of selenium during pregnancy. Factors other than selenium concentration, e.g. hormonal and genetic, might also affect the RBC GSH‐Px activity as suggested by sex differences and mother/child concordances in enzyme activity found in our cases.
Correlation between Serum IgG, Platelet Membrane IgG, and Platelet Function in Hypergammaglobulinaemic States
Authors: Mc Grath K. M. , Stuart J. J. , Richards F.
Published: March 2008

Summary. Platelet membrane IgG levels were measured by the complement lysis inhibition test, and were correlated with serum IgG levels in 29 patients with elevated immunoglobulins due to multiple myeloma, benign monoclonal gammopathy, systemic lupus erythematosis, rheumatoid arthritis, benign hypergammaglobulinaemic purpura and systemic infection. Platelet membrane IgG was increased in proportion to the elevation of serum IgG with a highly significant correlation coefficient (0.5615, P≤0.01), irrespective of the underlying disease state. Further washing of the platelets did not significantly alter the amount of membrane bound IgG. Qualitative platelet defects were present in nine of the 10 myeloma patients in whom platelet aggregation, platelet factor 3 availability, platelet adhesion to glass beads and bleeding times were studied. The most severe abnormalities occurred in those patients having the highest levels of platelet membrane IgG. Platelet function was normal despite markedly elevated platelet bound IgG in one patient with benign hypergammaglobulinaemic purpura. These findings indicate that elevation of serum IgG must be excluded before inferring the presence of platelet autoantibodies in patients with elevated platelet bound IgG. They also support the concept that the qualitative platelet abnormalities seen in multiple myeloma result from platelet coating by abnormal immunoglobulins or are secondary to myeloma effect on bone marrow.
‘Prolymphocytoid’ Transformation of Chronic Lymphocytic Leukaemia
Authors: Enno A. , Catovsky D. , O'Brien M. , Cherchi M. , Kumaran T. O. , Galton D. A. G.
Published: March 2008

Summary. We report clinical, morphological and surface marker studies on seven patients with the common type of chronic lymphocytic leukaemia (CLL) whose disease underwent an insidious though progressive change in character with increasing refractoriness to treatment. This transformation was accompanied by the appearance of a population of immature‐appearing cells in the peripheral blood which resembled prolymphocytes, both at light and electron microscopy. The characteristic morphological feature was the presence of two distinct populations of cells, the typical CLL lymphocytes and the ‘prolymphocytoid’ cells. These cells retained the surface marker characteristics of CLL, i.e. the formation of mouse RBC rosettes and sparse surface‐bound immunoglobulin. This transformation can be distinguished by morphological and surface marker criteria from acute leukaemia occurring in CLL, Richter's syndrome and prolymphocytic leukaemia. The recognition of this group of CLL patients may add a new prognostic index to CLL and may help plan subsequent trials for the treatment of the disease.
Inherited Aplastic Anaemia with Increased Endoreduplications: a New Syndrome or Fanconi's Anaemia Variant?
Authors: DOSIK H. , Steier W. , Lubiniecki A.
Published: March 2008

Summary. TWO sisters with aplastic anaemia without other congenital anomalies are described. Peripheral blood cytogenetic studies revealed an increase in endoreduplications in the absence of other unstable chromosome anomalies. Increased expression of T‐antigen following SV40 virus infection in vitro was demonstrated in both sisters, as well as other normal family members. We feel that these patients represent a variant of Fanconi's anaemia. The importance of performing chromosome studies in idiopathic aplastic anaemia is emphasized.