bluuebunny/crossref_metadata_2025 huggingface dataset:
Platelet fragments do not contribute to elevated levels of platelet associated IgG
Authors: Kelton John G. , Sheridan David , Neame Peter B. , Simon Gerard T.
Published: March 2008

Summary. Most assays that measure platelet associated IgG (PAIgG) relate the IgG associated with the test platelets to the platelet count. This could lead to a systematic error if platelet fragments were present in the washed platelet sample but not counted. To address this issue, we studied platelets from patients with idiopathic thrombocytopenic purpura (ITP), thrombocytopenia complicating cardiopulmonary bypass, and laboratory synthesized platelet fragments (freezethawed) using electron microscopy. Scanning electron microscopic (SEM) examination of the platelet samples demonstrated appreciable numbers of fragments only in the freeze‐thawed specimens. Yet, ‘fragments’ could be seen in all specimens using transmission electron microscopy (TEM). Most of these ‘fragments’ proved to be artefacts: we found that the ratio of ‘fragments’ to intact platelets observed in the TEM specimens was similar to the estimated ratio of ‘fragments’ to platelets that would have been generated had the specimens been sectioned at 90° to the plane of the actual section.

Platelets labelled with the membrane label 125I‐iodosulfanilic acid were fragmented by repetitive freeze‐thawing. Measurement of pellet radioactivity following washing indicated that the fragments were lost during the washing procedure.

These studies indicate that elevated levels of platelet associated IgG in ITP do not represent artefacts due to contamination of the test platelets by platelet fragments.
The effect of retinoids on CFU‐GM from normal subjects and patients with myelodysplastic syndrome
Authors: Bailey‐Wood R. , May S. , Jacobs A.
Published: March 2008

Summary. Five retinoid analogues differ in their effects on the growth of CFU‐GM from normal human marrow. At concentrations above 10−6 M all have inhibitory activity. This is maximal with 13‐cis‐retinoic acid. At lower concentrations the effect of retinoids is usually to reduce clone size rather than clone numbers though 10−8‐10−7 M etretinate increases clone size.

The incubation of marrow cultures in the presence of 10−6 M all‐trans retinoic acid showed that in normal subjects colony counts are never reduced to less than 45% of the control value and total clone counts to less than 70% of the control value. In cultures from patients with myelodysplastic syndrome 20 out of 34 cases showed a greater inhibition of colony numbers than normal and 14 out of 35 cases showed a greater reduction in total clone numbers than normal. The results suggest that CFU‐GM from some patients with myelodysplastic syndrome may have a greater sensitivity than normal to the inhibitory effect of retinoic acid.
Variable differentiation of human acute myeloid leukaemia during colony formation in vitro: a membrane marker analysis with monoclonal antibodies
Authors: Touw Ivo , Löwenberg Bob
Published: March 2008

Summary. The capacities of human acute myeloid leukaemia (AML) cells for differentiation were evaluated by the degree of maturation of the cells following in vitro colony formation. For this purpose highly purified blast cells were seeded into culture. Exogenous differentiation inducers, other than the colony stimulating materials, were not added to the cultures. Phenotypes of the colony cells were determined by use of monoclonal antibodies directed against a number of maturation antigens. In all 10 cases marked changes in the surface phenotypes of the cells post culture were seen. Differentiation was incomplete and quite variable as compared with normal myeloid colonies. Following colony formation myeloid maturation antigens became apparent on the cells of the one patient with morphologically undifferentiated leukaemia. The residual differentiation capacities among individual cases of human AML, as revealed in vitro, are diverse and do not parallel the morphological maturation features of the blasts prior to culture according to the FAB nomenclature. This approach may be utilized to improve the classification of human AML and to disclose the lineage relationship of certain cytologically unclassifiable leukaemias.
Specific production of eosinophil colony stimulating factor from sensitized T cells from a patient with allergic eosinophilia
Authors: Enokihara Hideo , Hamaguchi Hiroyuki , Sakamaki Hisashi , Hazama Sakae , Saito Kenji , Furusawa Shimpei , Shishido Hideo
Published: March 2008

Summary. To explore the possibility that an eosinophil colony stimulating factor (EO‐CSF) is elaborated independently of neutrophil CSF (N‐CSF), we compared the effect on the production of EO‐CSF and N‐CSF of adding a specific antigen, an aspergillus extract, to peripheral blood leucocytes of an eosinophilic patient with allergic bronchopulmonary aspergillosis. Conditioned media prepared from the patient's mononuclear (MN) and T cells were assayed for EO‐CSF and N‐CSF activities by agar culture technique, using normal human nonphagocytic MN bone marrow cells as target cells. The addition of the specific antigen to the cultures of the patient's MN or T cells significantly stimulated the production of EO‐CSF, but not that of N‐CSF, while the patient's non‐T cells and normal MN or T cells were not stimulated by the antigen challenge to produce either CSF. These results suggest that EO‐CSF is a factor distinct from N‐CSF, that its production is dependent on the presence of sensitized T cells with antigen‐specific stimulation, and that it might be one of the causes of blood eosinophilia in this patient.
Lysosomal isoenzyme profiles used to classify a case of acute undifferentiated leukaemia
Authors: Eden O. B. , Darbyshire P. , Simpson R. McD. , Besley G. T. N. , Moss S. , Gentle T.
Published: March 2008

Summary. Lysosomal enzyme activities and isoenzyme profiles were measured in lymphoid and non‐lymphoid leukaemic cells from childhood patients. High activities, especially of β‐hexosaminidase and α‐mannosidase, were associated with leukaemic cells of myeloid or monocytic origin. Leukaemic cells from two children with acute myeloid leukaemia had a relative reduction in the B isoenzyme of β‐hexosaminidase activity, whereas in patients with non T, non B cell acute lymphoblastic leukaemia, intermediate β‐hexosaminidase isoenzymes were expressed. A patient is described on whom conventional marker studies were either negative or equivocal, but lysosomal enzyme markers were consistent with a myeloid leukaemia. This observation was supported by the clinical course of this patient.
Reduced thromboplastin activity in blood monocytes and reduced sensitivity to stimuli in vitro of blood monocytes from pregnant women
Authors: ØIan P. , Omsjø I. , Maltau J. M. , ØSterud B.
Published: March 2008

Summary. The thromboplastin activity in blood monocytes from 18 normal third trimester pregnant women has been compared with a group of 20 healthy non‐pregnant women. The thromboplastin activity in unstimulated monocytes from the normal pregnant group was on average 40% of the activity in the non‐pregnant group (P<0.01). In endotoxin stimulated monocytes, the thromboplastin activity was also significantly lower in the pregnant group as compared to the non‐pregnant group (P <0.001). Fibrinogen and factors V, VII and VIII were significantly higher in the pregnant than in the non‐pregnant group, whereas no difference was observed in AT‐III, prekallikrein and α2‐antiplasmin levels.
Membrane cross bonding in red cells in favic crisis: a missing link in the mechanism of extravascular haemolysis
Authors: Fischer T. M. , Meloni T. , Pescarmona G. P. , Arese P.
Published: March 2008

Red cells of G6PD (D‐glucose‐6‐phosphate:NADP+ 1‐oxidoreductase; G6PD) deficient (Mediterranean variant) subjects were studied during a fava bean haemolytic crisis. Two representative cases are described. In Case 1, haemolysis was still going on. In more than 50% of the red cells the Hb was confined to one part of the cell, leaving the other part as transparent as a Hb‐free ghost. In this part the membranes appeared tightly bonded because swelling did not peel apart the bonded membrane areas. This feature is defined as membrane cross bonding (MCB). In Case 2. haemolysis had terminated and MCB‐cells were less than 1%. MCB was reproduced in vitro by incubating G6PD‐deficient whole blood with 1 mM divicine for up to 10 h. Subsequent shrinkage of red cells in hypertonic plasma (400 mOsm) resulted in the rapid formation of MCB. Membrane modifications by divicine, contained in fava beans, followed by osmotic shrinkage in the kidney and/or squeezing in the microcirculation are proposed as the cause of MCB during the favic crisis. MCB reduces the effective surface area of red cells. This is a plausible cause for sequestration by the reticulo‐endothelial system. Intravascular haemolysis observed in favic crisis cannot be explained by mechanical forces, but it is possible that the effective surface area is reduced by MCB to such an extent that red cells lyse osmotically.
Zwa antigen distribution on the human platelet: an electron microscope study using a colloidal gold labelled marker
Authors: Saunders P. W. G. , Durack B. E. , Narang H. K.
Published: March 2008

Summary

We present the application of a new technique for visualizing surface antigen distribution patterns on intact platelets, treated with anti Zwa antibody, using colloidal gold labelled anti‐human immunoglobulin as a marker. Platelets from Zwa negative and from both heterozygous and homozygous Zwa positive individuals were examined for surface Zwa antigen distribution. Platelets fixed with paraformaldehyde show an even distribution of gold particles with a well‐developed reticular pattern over their surfaces. Platelets heterozygous for Zwa shows considerable antigen variation, some platelets having similar quantities of antigen to, others much less than, homozygotes. The importance of platelet fixation prior to antigen demonstration by anti Zwa antibody and immunogold visualization is seen by the redistribution of antigen on unfixed platelets. It is suggested that this technique could be exploited to investigate the relationship between platelet surface antigens or structures and their functions.
Purification of antithrombin ‘Vicenza’: a molecule with normal heparin affinity and impaired reactivity to thrombin
Authors: Finazzi G. , Tran T. H. , Barbui T. , Duckert F.
Published: March 2008

Summary

Antithrombin III (AT) ‘Vicenza’, a previously described dysfunctional AT associated with familial thrombosis, has been isolated by heparin affinity chromatography. The purified molecule has been investigated by SDS‐polyacrylamide gel electrophoresis and crossed immunoelectrophoresis after incubation with different amounts of thrombin. A normal affinity for heparin has been demonstrated. However, evidence is produced that AT ‘Vicenza’ poorly inhibits thrombin. Present data suggest that AT ‘Vicenza’ consists of a population of two molecules, half of which does not form a complex with thrombin however and loses its heparin affinity upon thrombin treatment.
Pathogenesis of hepatic fibrosis in experimental iron overload
Authors: Weintraub Lewis R. , Goral Anthony , Grasso Joseph , Franzblau Carl , And Albert Sullivan , Sullivan Susanne
Published: March 2008

Summary

Significant increases in prolyl hydroxylase activity, a key enzyme in the collagen biosynthetic pathway, were noted in the hepatic homogenates of iron‐loaded animals as compared to controls. The increase in prolyl hydroxylase activity was seen without any light microscopic histologic evidence of cell necrosis or accumulation of collagen in the livers from the iron‐loaded animals. However, utilizing electron microscopy, collagen fibrils were demonstrated immediately adjacent to the hepatocytes in the iron‐loaded animals but not the controls. No fibroblasts or inflammatory cells were noted in this area. There was no evidence of damage to the subcellular organelles of the iron‐loaded hepatocytes. The hydroxy‐proline content of the iron‐loaded livers was also shown to be increased. These experimental studies in conjunction with clinical observations described below suggest that in vivo iron overload may have a primary effect on stimulating collagen synthesis by hepatocytes.
Cyclical eosinophilia: a manifestation of periodic haemopoiesis?
Authors: Davies J. R. , Geary C. G. , Testa N. G. , Pumphrey R. S. H.
Published: March 2008

Summary. A patient is described who has had a marked eosinophilia of unknown cause for 9 years in association with episodic facial swelling. Weekly blood counts for 8 months showed cyclical variations in eosinophils, neutrophils and monocytes (mean cycle length 35 d). Marrow culture studies showed fluctuation in the incidence of granulocyte‐macrophage colonies (GM‐CFC), and the proportion of eosinophil colonies was higher than the values reported for normals. The blood lymphocyte T4/T8 ratio was reversed, due to an increase of T8 + cells. It is suggested that this condition is a rare form of periodic haemopoiesis.
Myelodysplastic syndromes: a study of 101 cases according to the FAB classification
Authors: Vallespi T. , Torrabadella M. , Julia A. , Irriguible D. , Jaen A. , Acebedo G. , Triginer J.
Published: March 2008

Summary. The myelodysplastic syndromes (MDS) are a group of closely related disorders characterized by chronic cytopenias with cellular marrow, poor prognosis and refractoriness to treatment. We studied 101 consecutive cases of MDS diagnosed over a 7–year period. Peripheral blood (PB) and bone marrow (BM) samples were reviewed and classified according to the proposals of the French–American–British (FAB) cooperative group for MDS. The combined analysis of the initial laboratory features and qualitative haematological abnormalities readily allowed the distinction between the different subgroups. Thirty‐two of 79 cases (40.5%) evolved towards other diseases, frequently acute leukaemia (24/79, 30%), or transformed into other MDS (7/79, 9%). In five cases, initially classified as refractory anaemia (RA) or refractory anaemia with ring sideroblasts (RAS), a transitory change to another type of MDS—two chronic myelomonocytic leukaemias (CMML), two refractory anaemias with excess of blasts (RAEB) and one refractory anaemia with excess of blasts ‘in transformation’(RAEB‐t)—was observed before the evolution towards acute leukaemia. This provides a new link between all these syndromes and increases the number of transitions to other MDS. Overall prognosis was very poor, with differences between subgroups. RA had the best prognosis whereas RAEB‐t had the worst one. This study shows that the FAB classification is readily usable and defines well‐characterized subgroups of MDS, although there are frequent transitional forms, and as the natural history of the MDS unfolds they may convert into another. The actual poor prognosis and the frequent evolution towards acute leukaemia makes necessary to investigate new methods of treatment for these disorders.
Increased growth and collagen synthesis of bone marrow fibroblasts from patients with chronic myelocytic leukaemia
Authors: Yonekura Shuji , Nagao Tadami , Arimori Shigeru
Published: March 2008

Summary. Growth and collagen synthesis were measured in human bone marrow fibroblasts derived from patients with chronic myelocytic leukaemia (CML) and normal individuals. The 3H‐thymidine uptake, growth rate and collagen synthesis of fibroblasts from patients with CML were significantly greater than those from normal subjects. Thus, there is increased proliferation and collagen synthesis of fibroblasts in patients with CML. These findings show that CML fibroblasts may display a greater sensitivity to stimulator contained in the fetal calf serum used for the cultures, and they are relevant to the myelofibrosis by bone marrow fibroblasts in this disease.
Phenotypic and karyotypic properties of hyperdiploid acute lymphoblastic leukaemia of childhood
Authors: Smets L. A. , Slater R. M. , Behrendt H. , Van't Veer M. B. , Homan‐Blok J.
Published: March 2008

Summary. The DNA/cell content was measured by flow cytometry in samples obtained from 98 unselected children with acute lymphocytic leukaemia (ALL) at diagnosis. The frequency of anomalies in modal DNA content was compared to that encountered in acute childhood non‐lymphocytic leukaemia (ANLL) and disseminated non‐Hodgkin's lymphoma (NHL). In ALL the most frequent (35%) aberration in DNA content was an increase by 20% relative to the modal value of normal white blood cells. This subcategory, referred to as hyperdiploid ALL (HD‐ALL), was characterized by a close association with the expression of the c‐ALL surface marker (20/20 patients) and characteristic numerical chromosome changes, including tri‐ or tetrasomy of chromosome 21. Moreover, patients with hyperdiploid ALL had a much lower peripheral leucocyte count (P= 0.001) than those with diploid disease and a varying proportion of their leukaemic cells existed in the peripheral blood as morphologically normal lymphocytes expressing the c‐ALL antigen. Within the standard risk category, patients with HD‐ALL had a longer disease‐free survival than those with diploid disease (P= 0.058). It is concluded that routine analysis by flow cytometry can conveniently and consistently detect ALL patients with hyperdiploid chromosome numbers. Hyperdiploid ALL constitutes a fairly large subtype of childhood ALL with specific biological and karyotypic properties, possibly associated with favourable prognosis.
Release of vascular plasminogen activator (v‐PA) after venous stasis: electrophoretic—zymographic analysis of free and complexed v‐PA
Authors: Stalder M. , Hauert J. , Kruithof E. K. O. , Bachmann F.
Published: March 2008

Summary. To better characterize the plasminogen activators present in the euglobulin fraction (EF) of plasma before and after venous occlusion, euglobulins of 30 healthy volunteers and of 32 patients with idiopathic thromboembolic disease were submitted to SDS‐PAGE and zymographic detection. The patterns thus obtained were compared to the fibrinolytic activity (FA) of the EFs measured on fibrin plates. There were significantly more patients with a low fibrinolytic response (FR) to stasis (difference between FA after and before stasis ≤0.3 TAU/ml) than controls (P<0.01). The electrophoretic–zymographic analysis revealed that: (i) in the resting state vascular plasminogen activator (v‐PA) is always present in a form exhibiting a mol wt of 110 000 (complex of v‐PA with its fast‐acting antiactivator); (ii) a high FR to stasis (> 1.3 TAU/ml) is always associated with the presence of free v‐PA (68 kdalton band); (iii) free v‐PA is never detected when the FR is low; and (iv) a poor FR is generally (15 of 17 patients with low FR) associated with apparently complete inhibition of the released v‐PA by the fast‐acting antiactivator; in the two remaining patients in whom no broadening of the 110 kdalton band is observed, the release mechanism for v‐PA is probably impaired.
Myelodysplastic syndromes: a scoring system with prognostic significance
Authors: Mufti G. J. , Stevens J. R. , Oscier D. G. , Hamblin T. J. , Machin D.
Published: March 2008

Summary 141 patients with MDS were classified according to the FAB criteria and followed up for a period of 4–192 months. It was recognized that patients with RAEBT had a uniformly poor prognosis. However, there was a wide variation in survival among the other subgroups. A score of 1 was assigned to each of the following presenting haematological features: bone marrow blasts ≤ 5%, platelets ≤ 100 × 109/1, neutrophils ≤ 2.5 × 109/1 and Hb ≤ 10.0 g/dl. Therefore the score for each patient ranged between 0 and 4. There were no statistically significant differences between those patients who scored 0 or 1, or between those who scored 2 and 3. Therefore patients were put into three groups: Group A (score 0 or 1), Group B (score 2 or 3), Group C (score 4). The differences in survival between each of the three groups are highly significant (P<0.00001). This system further separates patients with RA, RAS, RAEB into good and bad prognostic groups.

This study also confirms that deaths due to cytopenias are more common than those due to transformation to AML. The use of this scoring system in conjunction with the FAB criteria for MDS should serve as a prognostic tool on which to base treatment.
Differentiation of patients with subtype IIb‐like von Willebrand's disease by means of perfusion experiments with reconstituted blood
Authors: Sakariassen Kjell S. , Nieuwenhuis H. Karel , Sixma Jan J.
Published: March 2008

Summary Four unrelated patients with a bleeding diathesis (bleeding time longer than 30 min), some spontaneous platelet aggregation, thrombocytopenia and large platelets, had decreased levels of factor VIII‐von Willebrand factor (FVIII‐VWF) related properties and impaired platelet adherence to human artery subendothelium. The largest multimers of plasma FVIII‐VWF were absent and enhanced ristocetin induced platelet aggregation in platelet‐rich plasma was observed.

‘Pseudo‐von Willebrand's disease’ was excluded, because FVIII‐VWF from normal subjects did not initiate platelet aggregation. Perfusion studies with reconstituted blood, consisting of respectively patient platelets in normal plasma or normal platelets in patient plasma, yielded evidence for an intrinsic platelet abnormality in two out of the four patients and a plasma defect in the other two patients. Similar experiments with platelets and plasma from four patients with von Willebrand's disease (VWD) subtype I and four patients with VWD subtype IIa showed that the impaired platelet adherence in blood from these patients was caused by a plasma defect.

These experiments indicate that patients with laboratory findings in many respects similar to those originally reported for patients with VWD subtype IIb may represent a heterogeneous group of individuals. The data derived from our study imply that perfusion experiments with reconstituted blood offer a new approach in characterization of these patients, which may be more relevant for the treatment of the patients than characterization by ristocetin induced adsorption of FVIII‐VWF to platelets.
Investigation of a coagulation accelerating factor (CAF) in glomerulonephritis
Authors: Salem Hatem H. , Howard Margaret A. , Koutts Jerry , Firkin Barry G.
Published: March 2008

Summary A coagulation accelerating factor was purified from the plasma of two patients with glomerulonephritis (GN) who suffered from thrombotic complications. The factor co‐purified with factor VIII/von Willebrand factor complex (FVIII/vWf) and under dissociating conditions remained associated with the factor VIII coagulant activity (FVIII). Control purified FVIII/vWf showed no coagulation accelerating activity under the experimental conditions used. The levels of coagulation accelerating factor, FVIII and von Willebrand factor (vWf) were reduced by incubation with rabbit anti‐human FVIII/vWf or human anti‐FVIII serum indicating a close association of these three activities. Multimeric analysis of the plasma FVIII/vWf complex from the two patients demonstrated a reduction in the high molecular weight multimers and the presence of an additional band not present on analysis of normal FVIII/vWf. It is sugggested that the coagulation accelerating factor represents an active form of FVIII which has different in vitro properties to thrombin activated FVIII.
Unmasking of Kx antigen by reduction of disulphide bonds on normal and McLeod red cells
Authors: Branch Donald R. , Hian Anita L. Sy Siok , Petz Lawrence D.
Published: March 2008

Summary We have investigated the effect of dithiothreitol (DTT) treatment of human red cells upon the Kx blood group antigen. At low concentrations of DTT (≤2 mM) there is enhancement of the Kx antigen concomitant with the complete denaturation of the Jsa and Jsb antigens of the Kell blood system. This unmasking of the Kx antigenic site is near maximal using 2 mM DTT. At this concentration of DTT, only the Jsa and Jsb antigens are completely denatured; all other Kell system antigens tested (K, k, Kpb, Ku) are essentially unaffected. These results argue against the Kx antigen serving strictly as a carbohydrate precursor substance involved in a sequential biosynthetic pathway of Kell blood group antigens. Also, McLeod red cells, after treatment with DTT, were found to contain Kx antigen, although in much lower density than normal red cells, indicating that, although not a typical carbohydrate precursor substance, Kx may, nevertheless, be essential for the serological expression of Kell related antigens. It is hypothesized that the Kx structure and the Kell blood group antigen structure are two separate subunits associated in a quaternary conformation involving at least one interchain S‐S bond. Our results should allow for a clearer understanding of the relationship between the serological expression of the Kx antigen and the serologically observed reactivity of the Kell blood group antigens of individuals having normal, Ko and McLeod phenotypes.
Red cell kinetics in thalassaemia intermedia: its use for a prospective prognosis
Authors: Najean Y. , Deschryver F. , Henni T. , Girot R.
Published: March 2008

Summary A kinetic study of erythroid cell production and destruction (radioactive iron incorporation, red blood cell survival time, bone marrow scintigraphy) was performed in 12 cases of thalassaemia intermedia (six adults and six children), classified retrospectively, and compared to that performed in 17 cases of Cooley's anaemia.

Our results confirm the genetic heterogeneity of these cases, the level of Hb F varies from 30% to 100% and the non α/α chain synthesis is only statistically superior to that seen in Cooley's disease. On the other hand, the kinetic study clearly separates the cases who are, or will be, clinically intermediate, showing a higher radioactive iron medullary uptake, a less ineffective erythropoiesis than that seen in Cooley's disease, and a greater peripheral haemolysis. In our study, no overlap was seen between the two groups.

Iron kinetic study is then of prognostic interest and may help in therapy decisions, transfusion regimen and iron chelation, and splenectomy.
Incidence of hypertension after marrow transplantation among 112 patients randomized to either cyclosporine or methotrexate as graft‐versus‐host disease prophylaxis
Authors: Loughran T. P. , Deeg H. J. , Dahlberg S. , Kennedy M. S. , Storb R. , Thomas E. D.
Published: March 2008

SummaryWe investigated the frequency of hypertension (sustained diastolic blood pressure ≥90 mmHg) in 112 patients given HLA‐identical marrow grafts. Patients were conditioned with 2 × 60 mg/kg of cyclophosphamide and 6 × 2 Gy of total body irradiation and randomized to receive as graft‐versus‐host disease prophylaxis either the standard methotrexate regimen (n= 61) or cyclosporine (n= 51), starting on day −1 as 12.5 mg/kg/d orally or as 3 mg/kg/d i.v. and later converting to p.o. when oral intake was tolerated. Kaplan‐Meier estimates indicate a 60% incidence of hypertension in the first 120 d in patients given cyclosporine (median time to onset: 4 d post transplant) compared to 20% in patients given methotrexate (P<0.0001). Multifactorial analysis using a Cox regression model showed that cyclosporine was the most significant risk factor for developing hypertension (relative risk: 32.1,P<0.0001). In addition, glucocorticoids, used for treatment of GVHD, were associated with an increased risk for hypertension (relative risk 7.2,P<0.0001). Age, sex, underlying disease, cyclosporine trough levels, and renal function had no significant association with hypertension. Early therapy of hypertension in cyclosporine‐treated patients appears to be indicated.
An immunoradiometric assay for human factor VIII/von Willebrand factor (VIII:vWF) using a monoclonal antibody that defines a functional epitope
Authors: Goodall Alison H. , Jarvis Jacky , Chand Sadhna , Rawlings Eira , O'Brien Donagh P. , McGraw Angus , Hutton Ronald , Tuddenham Edward G. D.
Published: March 2008

Summary A murine monoclonal antibody has been produced (RFF‐VIII:R/2) that binds specifically to human factor VIII‐related antigen (VIII:RAg) in plasma and in vascular endothelial cells but has no reactivity with factor VIII procoagulant antigen (VIII:cAg). This antibody is a potent inhibitor of von Willebrand factor activity (VIII:vWF) in that it can totally neutralize ristocetin‐induced aggregation of platelet rich plasma and inhibit platelet adhesion at high flow rates. RFF‐VIII:R/2 can be used in a one‐stage, fluid phase immunoradiometric assay that can detect VIII:RAg at concentrations of 0.001 u/ml. This method has been used to analyse plasma from patients with von Willebrand's disease (vWD). Results obtained in these patients showed a high degree of correlation between the monoclonally‐defined epitope and VIII:vWF levels measured by ristocetin‐induced aggregation of washed platelets. This correlation was maintained in those patients with the ‘variant’ types of vWD who exhibit highly disparate VIII:vWF and VIII: RAg levels when the latter is determined using polyclonal antisera. It appears that this monoclonal antibody recognizes a site on the VIII:RAg molecule which is associated with its interaction with the platelet membrane. Immunoradiometric assays using RFF‐VIII:R/2 offer a simplified, reproducible means of detecting functionally‐active VIII:RAg as an alternative or supplement to techniques involving platelet interactions.
The destabilization of factor VIII by a vitamin K dependent protein
Authors: Waintraub Stanley E. , Sussman Ira I.
Published: March 2008

Summary Since a vitamin K dependent protein, protein C, can inactivate factor VIII, a study was undertaken to determine if the level and stability of factor VIII in plasma are influenced by such a protein. Factor VIII lability was determined by incubating citrated plasma, diluted 1:10 and 1:20 in pH 7.2 imidizole buffer, for 6 h at 37°C. Normal plasma had a mean factor VIII of 98 ± 61 U/100 ml. The amount of factor VIII remaining after 6 h of incubation was 68 ± 14% of the original factor VIII level. In warfarinized patients, factor VIII (218± 65 U/100 ml) and VWF:AGN (331 ±102 U/100 ml) were elevated (P<0.001). Following incubation, their residual activity was 103 ±20% of the original factor VIII level. In samples taken after warfarin was discontinued, normal factor VIII lability returned, while plasma levels of factor VIII and VWF: AGN remained elevated. Similarly, in the plasma of a vitamin K deficient patient, increased factor VIII stability was also evident; lability was restored following vitamin K replacement. We conclude that factor VIII stability is determined in part by a vitamin K dependent protein. In clinical states in which this protein is functionally absent, factor VIII is elevated and more stable.
Control of lysozyme gene expression in differentiating HL‐60 cells
Authors: Polansky Daniel A. , Yang Angela , Brader Kevin , Miller D. M.
Published: March 2008

Summary

We have investigated the control of lysozyme gene expression in HL‐60 cells induced to differentiate into macrophage‐like cells with phorbol myristate acetate (PMA). Differentiation, as evidenced by cellular adherence, and morphological changes corresponded temporally to an increase in nonspecific esterase activity. The lysozyme concentration in the medium of uninduced HL‐60 cells was 10 μg/107 cells. increasing to a maximum of 46 μg/107 cells after 48 h incubation with PMA (16 nm). At 72 h the lysozyme concentration decreased to 16 μg/107 cells. Intracellular lysozyme activity remained constant throughout differentiation. If HL‐60 cells were exposed to PMA for 24 h, washed, then maintained in normal medium, they differentiated normally, confirming their irreversible commitment to differentiate. The increase in lysozyme secretion by these cells, however, is markedly blunted suggesting that continued PMA treatment of differentiated cells is required for their secretion of lysozyme. There is no change in the rate of extracellular degradation of lysozyme during differentiation. The level of lysozyme mRNA does not correlate directly with the amount of lysozyme secreted into the medium. Hybridization of uninduced HL‐60 cell RNA with a chicken lysozyme cDNA probe demonstrates moderate hybridization. There is a modest (five‐fold) increase in lysozyme mRNA between 0 and 36 h of exposure to PMA, corresponding to the burst of lysozyme secretion by these cells. The lysozyme mRNA decreases to a level which is lower than the original baseline by 72 h, when the cells are still secreting substantial amounts of lysozyme. These data suggest that both transcriptional and post‐transcriptional controls are operative in the control of lysozyme gene expression during the differentiation of HL‐60 cells. They also imply that lysozyme secretion is not a necessary component in the macrophage‐monocyte differentiation of these cells.
Platelet associated complement components (PAC3c and PAC3d) in patients with autoimmune thrombocytopenia
Authors: Hegde U. M. , Bowes A. , Roter B. L. T.
Published: March 2008

Summary

Platelet associated C3c and C3d (PAC3c and PAC3d) were quantitated by enzyme linked assay in 105 patients with idiopathic autoimmune thrombocytopenia (AITP) in whom elevated platelet associated immunoglobulins (IgG and IgM) had previously been documented. Increased levels of complement components were demonstrated in 46 of 105 patients (43.8%). In 11 of these patients, PAC3d alone was abnormal implying that C3b had been inactivated after cleavage by C3 inactivator in vivo. Complement binding was seen in two of 16 patients (12.5%) with raised PAIgG alone, four of 19 patients (21.0%) with raised PAIgM alone and in 40 of 70 patients (57.1%) in whom PAIgG and PAIgM were raised together. This difference was highly significant (P= 0.01). The clinical implication of these findings are discussed.
A sensitive cytochemical staining method for glucose‐6‐phosphate dehydrogenase activity in individual erythrocytes II. FURTHER IMPROVEMENTS OF THE STAINING PROCEDURE AND SOME OBSERVATIONS WITH GLUCOSE‐6‐PHOSPHATE DEHYDROGENASE DEFICIENCY
Authors: Van Noorden Cornelis J. F. , Vogels Ilse M. C.
Published: March 2008

Summary

A cytochemical method for staining glucose‐6‐phosphate dehydrogenase (G6PD) activity in individual erythrocytes as reported previously has been optimized further by the incorporation of a number of technical improvements. Analysis of the enzyme content in erythrocytes of normal individuals as well as patients suffering from G6PD deficiency in the homozygous and heterozygous forms allows these three categories to be easily distinguished. Considerable formazan production occurs in most erythrocytes of a healthy person and only a small percentage of the cells appeared to be negative. Two cell populations of almost equal size could be discerned in heterozygotes for G6PD deficiency, one completely negative, the other with a variable amount of formazan per cell. Homozygous deficiency leads to a population of negative cells with a few positive ones after staining. It is concluded that a reliable method has been found for analysis of G6PD deficiency in erythrocytes at the single cell level.
Transient expression of a second monoclonal component in two forms of biclonal gammopathy
Authors: Bast E. J. E. G. , Slaper‐Cortenbach C. M. , Verdonck L. F. , Samson W. , Ballieux R. E.
Published: March 2008

Summary

Two cases of transient biclonal gammopathy are described, one having an IgGK and an IgAK monoclonal component and another with IgG1K and IgGK monoclonal components. In both of these cases the second monoclonal component gradually disappeared. Anti‐idiotypic antibodies were made against the major monoclonal serum component; in the first case the idiotype of the IgGK clone was not found in the IgAK plasma cells (real biclonal gammopathy) whereas in the second case the idiotypes of the two clones were identical (apparent biclonal gammopathy). The evolution to monoclonal gammopathy is discussed with regard to the existence of common malignant precursor cells in biclonal gammopathy.
Platelet hyperaggregability occurring during prolonged continuous intravenous infusions of prostacyclin analogue ZK 36374
Authors: Yardumian D. A. , Mackie I. J. , Bull H. , Goldstone A. H. , Machin S. J.
Published: March 2008

Summary

We describe two patients suffering from vascular problems refractory to conventional treatment, who received prolonged continuous infusion of ZK 36374, a stable prostacyclin analogue. During the infusion, the patients' platelets became progressively refractory to the in vitro inhibitory action of exogenous ZK 36374. During the early stages of the infusions, platelet aggregability studied ex vivo was inhibited, but this effect too diminished progressively as the infusions continued. The platelets of one patient become spontaneously aggregable and hyperaggregable to standard agonists during the last 2 d of his 9 d infusion. This effect was not seen during an initial 10 d infusion in our second patient, who was concurrently receiving indomethacin, a reversible cyclo‐oxygenase inhibitor. However, such hyperaggregability became evident in the platelets of this patient during a second, shorter continuous infusion after cessation of the indomethacin. The hyperaggregability was accompanied in each case by a significant rise in serum thromboxane B2 levels.
Haematological change in sickle cell–haemoglobin C disease and in sickle cell‐beta thalassaemia: a cohort study from birth
Authors: Stevens M. C. G. , Maude G. H. , Beckford M. , Grandison Y. , Mason K. , Serjeant B. E. , Taylor B. , Topley J. M. , Serjeant G. R.
Published: March 2008

Summary

The haematological changes in early years following neonatal diagnosis have been observed in representative groups of children with sickle cell‐haemoglobin C (SC) disease, sickle cell‐β+ thalassaemia, and in sickle cell‐β° thalassaemia.

Most haematological indices in SC disease were intermediate between previously published values in SS disease and in AA controls, generally being closer to values in normal children. Exceptions were microcytosis which may be genetically determined and a striking elevation of mean cell haemoglobin concentration from age 2 months to 4 years. The combination of a raised MCHC and a lowered MCV is unusual and may be characteristic of SC disease.

Features in sickle cell‐β thalassaemia generally differed according to the type ofβ thalassaemia gene. Sickle cell‐β° thalassaemia had lower levels of haemoglobin, MCHC, red cell count, MCV, and higher reticulocytes, most differences being significant before 1 year. No differences between Sβ° thalassaemia and Sβ+ thalassaemia were apparent in HbF levels (which resembled those in SS disease) or in HbA2 levels (which exceeded those in SS disease by 1 year of age).
An ultrastructural study of stored human platelets after washing using prostacyclin
Authors: Read N. G. , Radomski M. W. , Goodwin D. A. , Moncada S.
Published: March 2008

Summary

The morphology of washed human platelets stored at 4°C has been examined over a period of 96 h. Platelets prepared using prostacyclin showed good preservation of their internal structure. These platelets showed no signs of activation when stirred in an aggregometer and only small reversible aggregates were formed during storage. In contrast, platelets prepared using a more conventional method, which does not use prostacyclin, showed poor preservation of internal structure. Storage and stirring of these platelets resulted in activation and morphological deterioration. These observations support our previous finding that prostacyclin prolongs the viabilty of washed human platelets in vitro.
Standardization of prekallikrein activator (PKA): the 1st International Standard for PKA
Authors: Kerry P. J. , Curtis A. D. , Thomas D. P.
Published: March 2008

Summary

A international collaborative study was carried out to establish an international standard for prekallikrein activator (PKA). The candidate material, coded 82/530, was assayed against the Office of Biologics (FDA) PKA reference preparation No. 2 (OoB 2) and the 1st British Reference Preparation for PKA. There was good agreement between participant laboratories on the relative PKA activity of the three preparations. Preparation 82/530 has been established by the World Health Organization as the 1st I.S. for PKA, with an assigned potency of 85 International Units per ampoule.
Prognostic value of B‐cell mitogen‐induced and spontaneous thymidine uptakein vitroin chronic B‐lymphocytic leukaemia cells
Authors: Juliusson Gunnar , Robèrt Karl‐Henrik , Nilsson Bo , Gahrton Gösta
Published: March 2008

Summary

Blood lymphocytes from 50 patients with chronic B‐lymphocytic leukaemia (B‐CLL) were culturedin vitrowith and without the polyclonal B‐cell activators (PBA) dextran sulphate (DxS), lipopolysaccharide fromE. coli(LPS), and Epstein Barr virus (EBV). Patients with blood lymphocytes that showed a high spontaneous or PBA‐induced3H‐thymidine uptake in 4 d cultures had a significantly shorter therapy‐free survival than patients whose lymphocytes showed a low thymidine uptake. The DxS‐induced cellular thymidine uptake was the most powerful predictor of prognosis. Eighteen patients with leukaemic cells responding to DxS stimulation had a median therapy‐free survival of 17 months and a probability of 5 year therapy‐free survival of <0.1, whereas for 30 patients with DxS unresponsive cells the corresponding figures were >120 months and >0.7, respectively (log rank,P<0.0001). A multivariate Cox's regression analysis revealed that the DxS‐induced leukaemic cell response was of greater prognostic importance than clinical features such as blood counts and staging according to Rai and Binet. Therefore PBA‐induced leukaemic cell thymidine uptake seems valuable in the prediction of prognosis in B‐CLL.
High risk of non‐A non‐B hepatitis after a first exposure to volunteer or commercial clotting factor concentrates: effects of prophylactic immune serum globulin
Authors: Kernoff P. B. A. , Lee C. A. , Karayiannis P. , Thomas H. C.
Published: March 2008

Summary

After a first exposure to factor VIII concentrates, 9/9 British patients treated with U.S.A.‐derived commercial products, and 10/12 treated with British volunteer (NHS) products, developed acute non‐A, non‐B (NANB) hepatitis. Hepatitis following commercial products was more severe, and of shorter incubation. High previous exposure to NHS blood products seemed to prevent NHS but not commercial factor VIII‐induced hepatitis; the latter was also not attenuated by administration of U.S.A.‐derived commercial immune serum globulin (ISG). After a first exposure to NHS factor IX concentrates without ISG, 4/4 patients developed short incubation NANB hepatitis; one also contracted prolonged incubation hepatitis B. One patient treated with ISG and factor IX of proven infectivity did not develop hepatitis, suggesting protection by ISG. Observed differences between concentrates might be attributable to their content of different NANB agents, but dose‐related effects could provide alternative explanations. This data provides a basis for comparative assessment of new products of possible reduced infectivity in only small numbers of patients.
Effects of cetiedil on the oxidative metabolism of activated polymorphonuclear leucocytes
Authors: Kohzaki Hitoshi , Kakinuma Katsuko , Asakura Toshio , Yamakawa Tamio
Published: March 2008

Summary

Cetiedel, α‐cyclohexyl‐3‐thiopheneacetic acid 2‐ (hexahydro‐lH‐azepin‐1‐yl)‐ethyl ester, was found to specifically suppress oxygen uptake by polymorphonuclear leucocytes (PMN) that were exposed to myristate or heat‐killed E. coli. The chemical had no effect on the basal respiration rate of PMN in the resting state. Inhibition of oxygen uptake by cetiedil was proportionate to the degree of inhibition of the generation of O‐2 and H2O2. It was also found that cetiedil suppressed the rate of the phagocytosis by PMN of opsonized oil droplets. Cetiedil had no effect on subcellular NADPH oxidase, an enzyme responsible for the respiratory burst that is activated by the perturbation of PMN plasma membrane with phagocytable particles or stimulators such as myristate. These results suggest that cetiedil affects the trigger mechanism of the plasma membrane to inhibit the activation of NADPH oxidase.
Multiple myeloma in a pair of monozygotic twins: the first reported case
Authors: Judson I. R. , Wiltshaw E. , Newland A. C.
Published: March 2008

Summary

A pair of monozygotic twins both developed multiple myeloma within a 2 year period. The first patient is alive with stable disease 4 years later, his twin brother died within a year of diagnosis. Monozygosity is well established and in both cases the paraprotein was IgGK. The relative influence of environmental and hereditary factors on the aetiology of myeloma is discussed. We believe this to be the first case of myeloma in twins to be reported.
A monoclonal antibody against a Burkitt lymphoma associated antigen has an anti‐Pk red blood cell specificity
Authors: Fellous Marc , Cartron Jean‐Pierre , Wiels Joelle , Tursz Thomas
Published: March 2008

Summary

The blood group specificity of a rat IgM monoclonal antibody (38–13) directed against most EBV‐positive or ‐negative Burkitt's lymphoma was investigated. The target antigen was previously identified as the neutral glycolipid ceramide trihexoside (CTH), a substance which accumulates in red cells from very rare individuals of the Pk phenotype and which appears as a normal intermediate in the biosynthetic pathway of the P blood group antigen (globoside).

The 38–13 antibody agglutinated Pk/1 and Pk/2 red cells at 4°C with a very high titre but was inactive against native P1, P2 and p erythrocytes, although a very weak activity was noticed towards papain‐treated P1 and P2 erythrocytes. These results were confirmed by an indirect radio‐binding assay which also demonstrated that the 38–13 antibody reacted with lymphocytes, fibroblasts and EBV‐positive lymphoblastoid cell lines derived from Pk/1 and Pk/2 individuals but not from other donors.

These findings demonstrate that the 38–13 monoclonal antibody previously considered as specific of Burkitt cells could be routinely used as an anti‐Pk blood group typing reagent. The mechanism of CTH accumulation in Burkitt cells and Pk red cells is probably different and might be associated respectively with the activation of an α‐4‐galactosyltransferase or the genetic blockage of a β‐3‐N‐acetylgalactosa‐minyltransferase.
Suppression of clonal evolution in two chronic myelogenous leukaemia patients treated with leucocyte interferon
Authors: Talpaz M. , Trujillo J. M. , Hittelman W. N. , Keating M. J. , Gutterman J. U.
Published: March 2008

Summary

Two patients with Philadelphia chromosome‐positive (Ph1 +) chronic myelogenous leukaemia (CML) were treated with human leucocyte interferon (HuIFN‐α). Karyotypic changes in addition to the Ph1 chromosome developed in these patients before the start of HuIFN‐α treatment. In one patient the administration of HuIFN‐α resulted in clinical haematological remission and stable suppression of the secondary Ph1 clone. The second patient was in myeloid blastic crisis when given HuIFN‐α. While she was receiving HuIFN‐α, suppression of the blast cell population in the bone marrow occurred. The subsequent cytogenetic changes included a near‐complete suppression of a secondary Ph1 clone of cells carrying a deletion in the short arm of chromosome 7 and partial population of the bone marrow with primary Ph1 clone. These observations suggest a potential role for interferons in altering the progressive course of CML.
Changes in platelet immunoprotein levels during therapy in adult immune thrombocytopenia
Authors: Ball S. , Zuiable A. , Roter B. L. T. , Hegde U. M.
Published: March 2008

Summary

Very early falls in platelet associated IgG, IgM and C3d were demonstrated following therapy with high dose i.v. immunoglobulin and with fresh frozen plasma. This suggests that the changes in platelet immunoproteins may be a primary event and that interference with antibody binding is a possible early mode of action of i.v. IgG.