bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of Storage Iron in the Pregnant Rat
Authors: Wyllie John C. , Kaufman Nathan 
Published: March 2008

Summary. It has been established that maternal storage iron is depleted during pregnancy in order to supply part of the iron required by the developing foetus and by the increasing red cell mass of the mother. It is also accepted that ferritin and haemosiderin are equally available as sources of storage iron.We measured the quantity of ferritin and haemosiderin in the liver and spleen of the rat at intervals during the latter half of pregnancy and have shown that ferritin iron is reduced whereas haemosiderin iron remains unchanged. The 2 and 24 hr uptake of 59Fe by these compounds was also measured. 59Fe is incorporated into both compounds; the uptake of 59Fe by ferritin falls in late pregnancy. Newlydeposited 59Fe is withdrawn from ferritin but not from haemosiderin.These results indicate that ferritin is the major source of storage iron in the pregnant rat. Ferritin iron is reduced in the liver and spleen because of a decreased uptake of iron as well as an increased mobilization.
A Controlled Trial of Joint Aspiration in Acute Haemophilic Haemarthrosis
Authors: Ingram G. I. C. , Mathews J. A. , Bennett A. E. 
Published: March 2008

Summary. Twelve severely affected haemophiliacs presenting with 22 acute haemarthroses of the knee were admitted to a trial in which, with their consent, they were treated either by intravenous infusion of human antihaemophilic factor alone or by aspiration of the knee joint in addition. The trial was restricted to patients with haemarthroses of intermediate size, as only in this situation were the indications for aspiration considered doubtful. Thus, patients were excluded if there was insufficient knee swelling to make it likely that blood could be withdrawn, or if aspiration was positively indicated by distension causing continuous pain at rest.By the next day, a significantly greater average range of movement had been regained in the 11 aspirated knees than in the 11 knees not aspirated, although at 5 days the average improvements were nearly equal. In planning treatment of individual cases, this benefit must be set against the painfulness of the procedure.
Determinants of Prothrombinase Activity and Modification of Prothrombin Conversion by Thrombin‐Treated Factor V
Authors: Kandall Carol , Akinbami T. K. , Colman R. W. 
Published: March 2008

Summary. The development of an intrinsic two‐stage assay for factor V using highly purified protein components is described. Phospholipid, activated factor X, calcium ion and factor V are incubated together to form a prothrombinase. After addition of prothrombin, sequential aliquots are removed and tested for thrombin activity using fibrinogen as a substrate. The rate of thrombin generation is linear for at least 10 min and increases with increasing concentrations of factor V or activated factor X. At a fixed concentration of activated factor X, a linear relationship is observed between the logarithm of the initial rate of thrombin generation and the logarithm of the factor V concentration. Oligomeric forms of factor V generate parallel but non‐identical concentration curves indicating differing abilities to form prothrombinase.The rate of thrombin generation eventually decreases and a maximum thrombin concentration is attained. This phenomenon is not attributable to substrate exhaustion or to decay of prothrombinase activity. Evidence for the formation of an inhibitor during prothrombin conversion, which is directed against both prothrombinase and the reaction of thrombin with fibrinogen, is offered.Activation of factor V by thrombin is demonstrable in the two‐stage intrinsic system and in a modified extrinsic sequential technique. In both systems the time course and extent of activation are similar to those observed using a one‐stage extrinsic assay.Thrombin formation began immediately with or without prior exposure of factor V to thrombin. The ‘lag time’ observed by some previous workers is shown to be an artifact due to inappropriate extrapolation of the standard thrombin curve.
The Lysis of Paroxysmal Nocturnal Haemoglobinuria Red Cells by Serum and Cobra Factor
Authors: Kabakĉi Tomris , Rosse W. F. , Logue G. L. 
Published: March 2008

Summary. The complement‐sensitive red cells of patients with paroxysmal nocturnal haemoglobinuria (PNH) are haemolysed in the presence of serum and a protein factor present in cobra venom (CoF). The reaction of CoF and a serum factor, C3 proactivator, requires Mg2+. Once this interaction has taken place, the activation of C3 and the terminal components of complement can occur in the presence of EDTA and result in the lysis of PNH red cells.The concentration of reactants may be adjusted so that all of the complementsensitive red cells of PNH patients and the red cells of no other patients are lysed. A simple but specific and precise test for the presence of the complement‐sensitive red cells of PNH was devised. Normal human red cells treated with trypsin and neuraminidase are not lysed, whereas these cells treated with glutathione or 2‐aminoethylisothiouronium bromide (AET) are lysed.
Slow Rate of Haemichrome Formation from Oxidized Haemoglobin Bart's (γ4): A Possible Explanation for the Unequal Quantities of Haemoglobins H (β4) and Bart's in Alpha‐Thalassaemia
Authors: Rachmilewitz E. A. , Harari E. 
Published: March 2008

SummaryHaemoglobins A, H (β4) and Bart's (γ4) obtained from two adult patients with haemoglobin H and persistent haemoglobin Bart's were separated and eluted from starch block electrophoresis. The spectrum of oxidized haemoglobin Bart's separated from the two patients indicated the presence of a haemichrome. In this respect, the properties of oxidized y‐chains are similar to those of oxidized haem‐bear‐ing α‐chains and haemoglobin H.The rate of haemichrome formation was found to be different for each sub‐unit in the following order α > β > γ > α2β2. These in vitro observations correlate well with the properties of excess haemoglobin subunits present in vivo in red cells of patients with the thalassaemia syndrome: α‐chains precipitate as inclusion bodies in the bone marrow and β‐chains mainly in peripheral mature red cells while precipitates of γ‐chains have not been identified. On the other hand, γ‐chains are the most stable in a soluble form while α‐chains, even when present in excess, can hardly be detected in a soluble form.In the heterozygote for α‐thalassaemia an average of 6.0% haemoglobin Bart's usually diminishes during the first year without being replaced by a similar amount of haemoglobin H. In haemoglobin H disease large quantities of haemoglobin Bart's are replaced by much smaller amounts of haemoglobin H. Assuming that the genetic defect in α‐chain production is the same in foetal and adult life, the differences in solubility and stability between γ and β‐oxidized chains may explain this phenomenon. Since γ‐chains are stable in their oxidized form, they do not precipitate readily in contrast with β‐chains which form inclusion bodies.
Bone Marrow Involvement in Burkitt's Lymphoma: Results of a Prospective Study
Authors: Bluming Avrum Z. , Ziegler John L. , Carbone Paul P. 
Published: March 2008

SummaryEighty‐five previously untreated patients with Burkitt's lymphoma were studied prospectively for the development of generalized bone marrow involvement by tumour. Fourteen (16%) of the patients in this series manifested marrow tumour involvement at some time during the course of their disease and seven of these presented with this complication. Only 20% of the affected patients had a peripheral leukaemic picture with a high percentage of circulating tumour cells. The prognosis associated with this complication appeared to be slightly worse in patients developing this picture following initial therapy than in those presenting with it. Pretreatment bone marrow lymphocyte counts were found to be 50% higher in patients who later developed bone marrow tumour involvement than in those who remained free of this complication. The implications of these observations are discussed.
Uptake of Latex and Thorotrast by Human Platelets In Vitro: Effect of Various Chemicals Demonstrating Differing Mechanisms and Metabolic Requirements
Authors: Mant M. J. , Firkin B. G. 
Published: March 2008

Summary In vitro platelet uptake of latex and thorotrast has been studied in the presence of a number of chemicals which inhibit metabolism and alter platelet ukrastructure. Latex uptake appears to require energy from anaerobic glycolysis and divalent cations, and is relatively easily influenced by substances which alter platelet ukrastructure. Platelet ATPases play either no role or only a minor one, and intact microtubules are unnecessary. Energy requirements for thorotrast uptake appear to be minimal or absent, divalent cations are not needed, and gross alteration of platelet ukrastructure still allows small amounts of thorotrast to gain entry into a few platelets. Platelet ATPases and intact microtubules are unnecessary for thorotrast uptake. It is concluded that latex uptake is probably by an active phagocytic process and thorotrast uptake is by a different mechanism. The relationship of increased citric acid cycle activity to degranulation and particle uptake is discussed, and it is suggested that this respiratory burst is unnecessary for either of these events, and that it is not a necessary accompaniment of platelet phagocytosis, nor specific for this process.
The Effects of Collagen and Kaolin on the Intrinsic Coagulant Activity of Platelets. EVIDENCE FOR AN ALTERNATIVE PATHWAY IN INTRINSIC COAGULATION NOT REQUIRING FACTOR XII
Authors: Walsh P. N. 
Published: March 2008

SummaryCollagen and kaolin have been shown by other workers to initiate intrinsic coagulation by activating factor XII in plasma and to have complex effects on platelets. Because of the presence of collagen at sites of vascular injury there is good reason to believe that collagen has physiological importance in haemostasis. The present experiments were done to determine the effects of collagen and kaolin on platelets and to distinguish the platelet effects from the activity which these surface‐active agents produce in plasma.Using an albumin‐density‐gradient separation (ADGS) method for washing platelets free of loosely adsorbed coagulation factors, it is shown here that collagen can induce a coagulant activity in platelets which initiates intrinsic coagulation. This activity is independent of factor XII, provided factor XI is present. It is postulated that this collagen‐induced coagulant activity of platelets provides an alternative pathway, by‐passing factor‐XII activation, for initiating intrinsic coagulation. The existence of this alternative pathway may provide an explanation for the absence of a haemostatic defect in Hageman trait. The effects of kaolin were similar to those of collagen, but kaolin had greater capacity to activate plasma factor XII and platelet factor 3 and relatively less capacity to activate platelet‐associated factor XI.
Observations on the Myelocyte to Tissue Transit Time (MTT) in Acute Leukaemia and Other Proliferative Disorders
Authors: Galbbaith Peter R. , Advincula Edgardo G. 
Published: March 2008

SummaryThe myelocyte to tissue transit time (MTT) was determined by labelling leucocytes in vivo with radioactive diisopropylfluorophosphate (DF32P) and determining the time for labelled leucocytes to disappear from the blood. Normally this is complete in 22 days or less. Prolongation of MTT suggests that the later stages of granulopoiesis may be impaired (dysgranulopoiesis). Dysgranulo‐poiesis was found previously in patients with acute myelogenous and myelo‐monocytic leukaemia. In this study we have found that MTT was reduced during treatment of the acute leukaemia with cy to toxic drugs, suggesting that there was a defect in myelocyte maturation in this disease. In addition we have found evidence of dysgranulopoiesis in patients (a) whose acute leukaemia was in complete remission, (b) with myeloproliferative disorders, and (c) with obscure blood dyscrasias without leukaemia. These findings suggest that acute leukaemia may be antedated by a proliferative disorder more frequently than is usually apparent, and that remission of acute leukaemia does not necessarily depend upon marrow repopulation by normal cell lines.
Co‐ordinated Increase of Sodium Leak and Sodium Pump in Hereditary Spherocytosis
Authors: Wiley J. S. 
Published: March 2008

SummaryThe presence of an increased sodium leak into hereditary spherocytes up to three times normal has been confirmed from measurement of 22Na+ influx into red cells. 22Na+ influx was not identical to the net inward leak of Na+ but the two kept a constant relationship since influx was about double the net Na+ gain in both normal and abnormal cells incubated with ouabain. The intracellular concentration of Na+ ions in fresh cells from hereditary spherocytes was identical to that in normal red cells. Hereditary spherocytes showed increased maximal activity of a membrane ATP‐ase inhibited by ouabain and the Na+ concentration giving half‐maximal activation of this ATP‐ase was the same for spherocytes and normal cells. When the 22Na+ influx into red cells from nine patients with hereditary spherocytosis was compared with maximal activity of cation pump ATP‐ase in the same cells a significant correlation was obtained (r= 0.78, P > 0.01). The results indicate some linkage between the increase in the Na+ leak and functional number of active cation pumps in the membrane of hereditary spherocytes.
The Control of Oxygen Affinity of Red Cells with Hb‐Shepherds Bush
Authors: May A. , Huehns E. R. 
Published: March 2008

SummaryThe red cells of the original patient with Hb‐Shepherds Bush (Hb‐ShB 25%, Hb‐A 75%) have a physiologically significant increased oxygen affinity. This is one third due to the intrinsic raised oxygen affinity of Hb‐ShB and two‐thirds due to its diminished response to 2,3‐DPG, there being no interaction between the two haemoglobins present in the cells.
Erythrocyte Glutathione Peroxidase Content and Serum Tocopherol Levels in Newborn Infants
Authors: Emerson Pauline M. , Mason David Y. , Cuthbert Jean E. 
Published: March 2008

SummaryTwo methods for the determination of glutathione peroxidase (GSH‐Px) activity have been compared and the overall superiority of a linked‐enzyme system has been confirmed. The erythrocyte GSH‐Px activity was measured in 120 newborn infants and compared with older children and adults. A definite deficiency of the enzyme was found in the former group, but could not be related to evidence of haemolysis. A relationship between serum tocopherol levels and erythrocyte GSH‐Px was found and the possible implications are discussed.
The Role of Platelets in Intrinsic Factor‐Xa Formation
Authors: Walsh P. N. , Biggs Rosemary 
Published: March 2008

SummaryAlthough the essential role of phospholipid in the interaction of factors VII and IX has been demonstrated (Lundblad & Davie, 1964), detailed studies of platelet activity in intrinsic coagulation have not previously been reported. A basic test system has been developed for studying the interaction of factors XIa, VIII, IX, and X in the formation of factor Xa. Using platelets from normal and coagulation‐factor‐deficient donors, washed by albumin density gradient separation (ADGS), a comparative study of platelets and phospholipid in intrinsic factor‐Xa formation has been done under various test conditions.Both platelets and phospholipid (Folch) are shown here to play a part in intrinsic factor‐Xa formation, whereas neither enhances extrinsic factor‐Xa formation. Collagen promotes a platelet coagulant activity which increases the rate of factor‐Xa formation in the test system employed. The effect of collagen depends entirely on the presence on the platelet surface of factor XI, but not of factor XII. In contrast to collagen, adenosine diphosphate has no effect on this intrinsic platelet coagulant activity. In experiments carried out in the presence of naturally‐occurring inhibitors to active clotting factors (anti‐factors Ila, Xa, and XIa) it is shown here that contact product is adsorbed to the platelet surface where it is protected from destruction by antifactor XIa. Factor Xa is formed subsequently by the interaction of intrinsic clotting factors, which is presumed to occur on the platelet surface since factor Xa is found in association with the platelets, not the surrounding plasma.
The Metabolism of Maturing Reticulocytes
Authors: Gasko O. , Danon D. 
Published: March 2008

SummaryA functional Krebs tricarboxylic acid cycle was demonstrated to exist in rabbit reticulocytes by the following methods:

Measurement of the rate of oxygen consumption of the cells, using acetate and succinate as substrates.
Demonstration of the Crabtree effect exerted by glucose on cellular respiration.
Following the metabolic pathway of [2‐14 C]acetate, [3‐14 C]pyruvate and [6‐14 C]glucose and measuring the formation of labelled CO2 by the cells. The effects of some inhibitors of mitochondrial activity on this pathway were also studied.
Demonstration of the conversion of labelled acetate into various intermediates of the Krebs cycle by chromatography and autoradiography.
Intestinal Conversion of Folinic Acid to 5‐Methyltetrahydrofolate in Man
Authors: Whitehead V. Michael , Pratt Roy , Viallet André , Cooper Bernard A. 
Published: March 2008

Summary. In three adult subjects undergoing diagnostic umbilical vein catheteriza‐tion, the active stereoisomer of folinic acid (dl,‐5‐formyltetrahydrofolate) was metabolized during absorption and appeared in hepatic portal venous plasma as 5‐methyltetrahydrofolate. A small amount of 5‐formyltetrahydrofolate and probably of 10‐formylfolate was detected in hepatic portal venous plasma early during absorption as well.Peripheral venous plasma folate changes in these subjects and in two achlorhydric subjects fed folinic acid were similar, suggesting that isomerization of 5‐formyl‐ to 10‐formyltetrahydrofolate by gastric acid was not necessary for its subsequent metabolism by the intestinal cell.Similar increments in peripheral venous plasma folate followed feeding of comparable doses of folinic acid and folic acid, evidence that folinic acid may be effectively administered by mouth. When so administered, the effect in respect of all tissues except the intestine is essentially equivalent to the feeding of 5‐methyltetra‐hydrofolate itself.
Preparation of Suspensions of Washed Platelets from Humans
Authors: Mustard J. F. , Perry D. W. , Ardlie N. G. , Packham M. A. 
Published: March 2008

Summary: Methods have been developed for the preparation of suspensions of washed platelets from humans. Heparin is used in the washing fluids to prevent: thrombin generation and apyrase is used to prevent adenine nucleotide accumulation. Platelets suspended in Eagle's tissue culture medium containing albumin were more responsive to ADP than platelets in Tyrode's‐albumin solution. Addition of fibrinogen is required for maximum sensitivity to ADP‐induced aggregation. These platelets can be stored for 4 hr or more at 37°C in the presence of apyrase and maintain their ability to aggregate upon the addition of low concentrations of ADP.Without apyrase the platelets gradually become insensitive to ADP upon storage at 37°C; this is presumably caused by the accumulation of ADP in the suspending fluid because sensitivity can be partially restored by the addition of apyrase and further incubation.
Copper and Zinc Concentration in the Plasma of Leukaemic Children
Authors: Delves H. T. , Alexander F. W. , Lay Helen 
Published: March 2008

Summary. The concentrations of copper and zinc have been measured in the plasma of children with acute lymphoblastic leukaemia before and after treatment, and compared with healthy controls.The plasma copper concentrations were higher and the plasma zinc concentrations lower for the untreated leukaemic children than for the other two groups. The concentrations of both metals were altered after treatment to values approaching the normal range.The plasma copper: zinc ratio discriminated well between the untreated leukaemic children and the other two groups. This ratio might prove useful in monitoring the response to treatment.
A Three‐Year Study of Adolescent Boys Suffering from Haemophilia and Allied Disorders
Authors: Rainsford S. G. , Hall Angela 
Published: March 2008

Summary. Details concerning the frequency of bleeding in haemophilia, Christmas disease and von Willebrand's disease in adolescent boys are given. The results show that the frequency of bleeding remained constant throughout eight academic terms. There was no seasonal variation. Severity, as judged by frequency of bleeding, cannot be correlated entirely with factor‐VIII activity, there being evidence that there is some other factor in addition to factor VIII concerned with bleeding in haemophilia.Of 61 haemophilic boys treated, only one developed an inhibitor to factor VIII. A higher incidence of haematuria was observed among boys with factor‐VIII inhibitors. The advent of replacement therapy has increased the role of orthopaedic surgery. The requirements for the care of 50 boys suffering from serious coagulation defects are discussed, and indications for further research are suggested.
Lysozyme Activity in Human Neutrophilic Granulocytes
Authors: Hansen Niels Ebbe , Andersen Vagn 
Published: March 2008

Summary. Among five different methods for the extraction of lysozyme from human neutrophilic granulocytes (mechanical disruption, freezing‐thawing, sonication, solubilization with saponin and with n‐butanol), extraction with n‐butanol was found to give the highest lysozyme yield per cell. With this method the lysozyme content of neutrophilic granulocytes was measured in a control group with no haematological, renal or infectious disease, and in patients with bacterial infection, severe uraemia, and myeloproliferative disorders.It was found that the lysozyme concentration in normal human adults was 2.7 μg per 106 neutrophils. Intraneutrophilic lysozyme in patients with bacterial infection was reduced by 50% whereas the activity in patients with severe uraemia was reduced by 25%. The content in patients with myeloproliferative disorders was normal. The intraneutrophilic lysozyme content varied inversely with the severity of the infection as judged by the degree of neutrophil leucocytosis. Taking all patients examined, the intraneutrophilic lysozyme activity varied inversely with the degree of toxic granulation. A negative correlation was also demonstrated between neutrophilic lysozyme and the serum creatinine level.It is suggested that bacterial infection and uraemia suppress lysozyme synthesis in the bone marrow, although other mechanisms cannot be excluded. The consequences for neutrophil function are unknown.
A Method of Antithrombin Estimation using Plasma Defibrinated with Ancrod
Authors: Howie P. W. , Prentice C. R. M. , McNicol G. P. 
Published: March 2008

Summary. A method for the measurement of progressive antithrombin activity is described. Higher levels of antithrombin activity are found in plasma defibrinated with ancrod than in plasma defibrinated by heating to 56°C or by thrombin. As ancrod itself has no antithrombin activity, it is recommended as the best agent for defibrinating plasma prior to antithrombin estimation.The relationship between plasma and serum antithrombin concentration was studied in patients during oral contraceptive therapy. There was a fall in both plasma and serum antithrombin during this therapy but the fall in serum antithrombin was significantly greater than that seen in plasma; this reflects the fact that the serum antithrombin concentration is dependent on the degree of thrombin generation which has taken place during clotting.