bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decrease of Alpha‐Hasharon Globin in Beta‐Thalassaemia
Authors: Conconi F. , Alberti R. , Mariuzzi G. M. , Guglielmini C. , Vullo C. , Senno L. del 
Published: March 2008

In time course experiments performed in subjects carrying haemoglobin Hasharon and β‐thalassaemia the synthesis of αA‐, αHasharon‐, β‐ and γ‐globin has been determined. The α‐globin molecules synthesized in excess were found to be removed from the red cell cytoplasm (phenomenon characteristic of β‐thalassaemia, described by Bargellesi et al, 1968a); in addition the αHasharon‐globin molecules were removed at a faster rate than normal α‐globin. The preferential removal of the mutant α‐globin explains the reduced level of haemoglobin Hasharon found in subjects carrying the gene for β‐thalassaemia (Alberti et al, 1975).Reductions below normal levels of other haemoglobin variants occurring in the presence of the counterpart‐globin thalassaemia are probably determined through a similar mechanism.
The Effect of Deoxyuridine, Vitamin B12, Folate and Alcohol on the Uptake of Thymidine and on the Deoxynucleoside Triphosphate Concentrations in Normal and Megaloblastic Cells
Authors: Ganeshaguru K. , Hoffbrand A.V. 
Published: March 2008

SUMMARY Deoxyuridine suppression of labelled thymidine uptake tests were performed in the bone marrows of 58 patients with megaloblastic anaemia (haemoglobin less than 10.0 g/dl) and invariably gave values (range ro.3–58.8%) above the range in 16 control marrows (range 1.0–9.0%). Folinic acid corrected the test equally well in either folate or vitamin B12 deficiency, even at concentrations as low as 60 ng/ml. Folic acid also corrected the test equally well in either deficiency but was only effective at concentrations down to 5 μg/ml. Vitamin B12 (100 μug/ml) only corrected the test in vitamin B12 deficiency and 5‐methyltetrahydrofolate only corrected the test in folate deficiency at the concentrations tested between 60 and 1.2 μg/ml.Among 16 patients with subnormal serum levels of both vitamin B12 and folate, vitamin B12 partially corrected the test in eight, including all five with pernicious anaemia, but had no effect in the other eight.Despite the clear‐cut results of the dU suppression test, measurement of the deoxythymidine triphosphate (dTTP) concentration in normal and megaloblastic pliytohaemagglutinin stimulated lymphocyte cultures or short‐term bone marrow cultures gave no clear‐cut differences between normal and megaloblastic cells after addition of deoxyuridine nor did the addition of vitamin B12 folic acid or folinic acid either alone or with deoxyuridine produce consistent changes in the dTTP concentration in lymphocytes or bone marrow cells in megaloblastic anaemia.Alcohol caused a rise in deoxyadenosine triphosphate concentration in normal PHA‐stimulated lymphocytes which was concentration dependent but caused no consistent change in any of the other three deoxynucleoside triphosphate (dNTP) concentrations. Diphenylhydantoin (10‐3 m, 10‐4 m) had no consistent effect on any of the four dNTP concentrations.
Monocyte‐Induced Increase in Osmotic Fragility of Human Red Cells Sensitized with Anti‐D Alloantibodies
Authors: Fleer A. , Koopman Marion G. , von dem Borne A. E. G. Kr. , Engelfriet C. P. 
Published: March 2008

Summary.The mechanism by which human monocytes increase the osmotic fragility of red cells sensitized with Rhesus alloantibodies anti‐D was studied in vitro. Both the increase in osmotic fragility and the lysis of red cells by monocytes were enhanced by cytochalasin B and were inhibited by hydrocortisone. These effects were similar to the effects of these agents on lysosomal enzyme release by monocytes. However, hydrocortisone was completely ineffective when added I h after mixing monocytes and sensitized red cells. This indicates that the damage responsible for the fragility increase and lysis is completed within I h and suggests that it is due to lysosomal enzymes released by the monocytes. Since for the full expression of the osmotic fragility increase and lysis an incubation time much longer than I h is required, it appears that the latter phenomena are the non‐specific sequelae of damage inflicted upon the red cell by released lysosomal enzymes.
Erythrokinetic Studies in Hairy‐Cell Leukaemia
Authors: Castro‐Malaspina Hugo , Najean Yves , Flandrin Georges 
Published: March 2008

Summary. Erythrokinetics were studied in 29 patients with hairy‐cell leukaemia. In all cases there was an increase in plasma volume, closely correlated to the size of the spleen, indicating that the true degree of anaemia can only be appreciated by red cell volume measurement. Moderately increased haemolysis was observed in most cases, which did not correlate with the spleen size. Simultaneous study of autologous and isologous red cell life‐span suggested an extra‐corpuscular mechanism for the haemolysis in most patients.A quantitative erythropoietic defect, either relative or absolute, was found in half the cases, without any qualitative defect. Only one case showed erythroid metaplasia of the spleen. Thus marrow failure appears to be largely responsible for the anaemia and granulocytopenia in hairy‐cell leukaemia. A clear correlation was shown between the short‐term prognosis after splenectomy and the degree of hypersplenism. However, long‐term survival correlated chiefly with the degree of bone marrow failure, whether splenectomy had been carried out or not. The results indicate that isotope studies in hairy‐cell leukaemia are useful both in determining the best form of treatment and predicting survival.
Diamond‐Blackfan Syndrome: Evidence for T‐Cell Mediated Suppression of Erythroid Development and a Serum Blocking Factor Associated with Remission
Authors: Steinberg Martin H. , Coleman Mary F. , Pennebaker James B. 
Published: March 2008

Summary. Diamond‐Blackfan syndrome may be a disorder of cellular immunity. Lymphocytes from some patients are capable of suppressing erythropoiesis in cultures of normal bone marrow.We studied two adults with this disorder, both in complete unmaintained remission, using a technique for cloning peripheral blood erythroid precursors (BFU‐E) in culture. The BFU‐E may be an early, erythropoietin sensitive, erythroid committed stem cell. Under culture conditions, which employ fetal calf serum, neither patients cells formed normal numbers of erythroid colonies. Controls yielded 15.3 ± 5.2 BFU‐E/2.5 × io5 mononuclear cells. Culture of patients cells using autologous serum, promoted more normal growth of BFU‐E (21.4 ± 6.9 and 7.3 ± 2.3 BFU‐E/2.5 × io5 cells). Patient mononuclear cells, cocultured with normal cells, generally suppressed BFU‐E generation. Cocultures of normals were not inhibitory. Removal of T‐lymphocytes from patient mononuclear cells permitted normal growth of BFU‐E in coculture with controls. T‐cells depleted Diamond‐Blackfan mononuclear cells showed BFU‐E formation in fetal calf and autologous serum. Diamond‐Blackfan T‐cells inhibited BFU‐E formation by normal mononuclear cells.The cellular defect in Diamond‐Blackfan syndrome persists during complete remission and may be mediated by lymphocytes. The development of a serum factor which blocks the suppressive effects on erythroid precursors of a subpopulation of autologous T‐cells may be responsible for the development of remission in our patients.
Mechanism of the Decreased Erythropoiesis in the Water Deprived Rat
Authors: Giglio J. M. , Alippi R. M. , Barceló A. C. , Bozzini C. E. 
Published: March 2008

Radioiron uptake by erythrocytes, metabolic rate, erythropoietin formation during hypoxia and erythroid responsiveness to exogenous erythropoietin were determined in both starved and water deprived rats. The feed intake showed a marked and progressive reduction during water deprivation. The metabolic rates of rats deprived of either food of water declined progressively showing a 40% reduction 5 d after water deprivation or starvation began. At this time, the 24 h red blood cells 59Fe incorporation was 85% lower in both starved and dehydrated rats than in normal rats. Plasma erythropoietin levels in response to hypoxia were approximately 50% decreased in both starved and dehydrated rats. Both polycythaemic starved and polycythaemic water deprived rats injected with human urinary erythropoietin showed a 75% decrease in 59Fe incorporation into erythrocytes when compared to control rats.It is suggested that depression of erythropoiesis during water deprivation in the rat depends on a reduced sensitivity to erythropoietin, possibly associated with decreased production of the hormone. Since water deprived rats drastically reduce feed intake it is suggested that secondary starvation is the principal cause of the decreased erythropoiesis induced in the rat by water deprivation.
Comparison of in Vitro Effects of Normal IgG and of a Monoclonal IgG on the Rheological Behaviour of Erythrocytes
Authors: Rovel A. , Vigneron C. , Streiff F. 
Published: March 2008

Summary. Erythrocyte sedimentation, viscosity, electrophroetic mobility, and osmotic fragility were measured in a study of the rheological behaviour of the erythrocyte in vitro. In comparison with physiological saline solution, a suspending medium containing a γ2γ2 monoclonal IgG from a patient with multiple myeloma caused rheological changes 2–3 times as great as a medium with normal IgG.Our results demonstrate the existence of nonimmunological interactions between erythrocytes and normal or monocolonal immunoglobulins, and they raise questions about the widely held assumption that paraproteins are structurally ‘normal’.
Cellular Mechanisms in the Regulation of Iron Absorption by the Human Intestine: Studies in Patients with Iron Deficiency before and after Treatment*
Authors: Cox T. M. , Peters T. J. 
Published: March 2008

Summary.An in vitro method for measuring initial rates of iron uptake by mucosal biopsies of human duodenum was used to study control mechanisms for iron absorption. Within the physiological range of intraluminal concentrations (18–450 μmo1/1) iron influx has many features of active, carrier‐mediated transport. In biopsies from six patients with iron deficiency anaemia, uptake rates were increased 2–3–fold at the higher concentrations, when compared with normal controls (P < 0.01) and overall were related inversely to serum transferrin saturation. Uptake was examined in four anaemic patients before and after therapy: the enhanced uptake fell to normal after repletion with iron, but was not reduced in two patients treated initially by red cell transfusion alone. Total mucosal iron in the anaemic patients was significantly lower at 58±7 nmol/mg protein, compared with 129±25 nmol/mg in normal subjects (P < 0.05). In the serial studies, iron therapy for 6 weeks corrected the anaemia but did not restore mucosal iron levels to normal, even though uptake had fallen to control values. The experiments indicate that iron deficiency reversibly induces brush border iron carriers, and suggest that in man initial entry into the enterocyte rather than cellular retention of iron is a major regulatory step in the control of iron absorption.
Positive Interaction between Agonists in the Aggregation Response of Human Blood Platelets: Interaction between ADP, Adrenaline and Vasopressin
Authors: Grant J. A. , Scrutton M. C. 
Published: March 2008

Summary.ADP, adrenaline and vasopressin interact positively as agonists in aggregating human blood platelets in vitro. This interaction is maximal if the addition of two of the agonists is separated by 10–20 s but decreases rapidly at longer intervals especially at low agonist concentrations. The agonist concentrations at which positive interaction gives full aggregation are significantly less than those required for such a response to each agonist alone. The lowest concentrations at which adrenaline and vasopressin interact positively are at least two orders of magnitude greater than the normal blood concentrations of these hormones, and at least an order of magnitude greater than the concentrations achieved in pathological states. Specifically antagonizing the adrenaline and ADP receptors showed that the response was to the second agonist added to the system. An inhibitor of intracellular Ca2+ movement (tetracaine) is equally effective in blocking the responses generated by a single agonist or by interaction of two agonists. Inhibitors which increase cyclic‐3′,5′‐AMP concentration (adenosine, prostaglandin E1, dipyridamole) are more effective against the response to a single agonist than that to agonist interaction. These data suggest that positive agonist interaction results from effects on the concentrations of second messengers within the platelet rather than from a direct interaction on the membrane receptors or the transmembrane coupling mechanisms.
A Specific, Fluorescent Activity Staining Procedure Applied to Plasma and Red Blood Cells in Congenital Factor XIII Deficiency
Authors: Henriksson P. , Stenberg P. , Nilsson I. M. , Rasovic N. , Kezic J. , Stenbjerg S. 
Published: March 2008

Summary.The activity staining procedure introduced by Stenberg & Stenflo (1979) has been applied to studies on human blood transamidases (transglutaminases; endo‐γ‐glutamine:ɛ‐lysine transferases; e.g. factor XIII). The technique combines agarose gel electrophoresis with activity staining based on the transamidase catalysed incorporation of monodansylthiacadaverine (N‐(5–amino‐3–thiapentyl)‐5–dimeth‐ylamino‐1–naphtalenesulfonamide) into casein. The method permits detection of plasma factor XIII activity down to 1% of the normal adult standard. The technique was used on plasma from two patients with tentative congenital plasma factor XIII deficiency (based on clot solubility). No activity was found in platelet poor as well as in platelet rich plasma which confirmed the diagnosis. In the erythrocytes studied in one of the two patients, transamidase activity was present which means separate genetic determinations of the plasma and red blood cell transamidases. Using immunoelectrophoresis, the plasma factor XIII b subunit was found to be 43% and 44% of the concentration in normal standard plasma.
The Effects of Surgical Trauma on Human Granulopoiesis
Authors: Philip Mark A. , Standen Graham , Fletcher John 
Published: March 2008

Summary.Marked changes in the concentration and proliferative state of circulating granulocytic progenitor cells (colony forming units in culture; CFUc) were observed in female patients following surgical trauma. Within one day of an abdominal hysterectomy there was an abrupt fall in the number of blood CFUc to between 10% and 20% of normal and an increase in the proportion synthesizing DNA which coincided with the maximum neutrophilia. Subsequently, as the neutrophil count declined, the CFUc concentration increased to supranormal values and the proliferative response persisted, both parameters returning to normal 2 weeks after surgery. These results suggest that, following surgical trauma, the increased demand for neutrophils is rapidly met by increased CFUc proliferation.
Glutamic Pyruvate Transaminase Phenotypes in Polycythaemia Rubra Vera
Authors: Kirkland D. J. , Welch S. G. , Povey Susan , Najfeld Vesna , Price D. J. , Lawler Sylvia D. 
Published: March 2008

Summary. Glutamate pyruvate transaminase (GPT) has been studied in the red cells of 46 patients with a confirmed diagnosis of polycythaemia rubra vera (PRV). The red cells of many of the patients showed low levels of enzyme activity. This activity could be restored by in vitro incubation with pyridoxal phosphate suggesting that the effect was due to low levels of B6 rather than to a primary abnormality of the GPT. Patients with the lowest levels of GPT activity were likely to have clonal chromosomal abnormalities in the bone marrow cells, particularly 20q —. Among 43 patients in whom the GPT phenotypes could be determined by an electrophoretic method there was a marked deficiency of heterozygotes. This disturbance in phenotypic expression may be related to the clonal nature of the disease in PRV, the clone showing lack of response to homeostatic controls and irregularities of gene expression.
Transient Increase of Fetal Haemoglobin in Kala‐azar
Authors: Schilirò G. , Musumeci S. , Russo A. , Marino S. , Sciotto A. , Russo G. 
Published: March 2008

Summary.Haemoglobin F (HbF) levels were significantly increawd in 40 children with kala‐azar in comparison with controls (3.36 ± 2.32 versus 0.90±1.8; P<0.01). The HbF was heterogeneously distributed among the red blood cells. The glycine residue of peptides γ CN3 were within the normal umbilical cord blood range, and the haemoglobin synthesis in vitro was balanccd. After recovery from kala‐azar the HbF fell within the normal range. These results suggest that increased production of HbF is associated with accelerated erythropoiesis due to temporary marrow stress.
Inhibitory Effect of Autologous Plasma on the Uptake of Tritiated Thymidine by Leukaemic Lymphoblasts and its Relation to Prognosis
Authors: Sugden P. J. , Lilleyman J. S. 
Published: March 2008

Summary. In vitro incorporation of tritiated thymidine was measured in blast cells from 33 unselected and untreated patients with lymphoblastic leukaemia (ALL) both when autologous plasma was present and also when it was substituted by pooled normal plasma. A similar procedure was carried out on 19 patients with acute non‐lymphoblastic leukaemia (AnonLL).Plasma from the patients with ALL was variably found to reduce the uptake of the radiolabelled DNA‐precursor by their own blasts, with the most marked effect apparent in those with shorter survival times (P < 0.42). This phenomenon was not observed in AnonLL. The amount of plasma‐mediated inhibition shown by the ALL patients also correlated overall with their WBC, a known feature of a poor outlook, but even in the 21 patients with WBC below 20.0 ± 109/1 there was still a significant association between plasma effect and survival (P < 0.01).The demonstration of such inhibitory plasma may be a useful prognostic marker in otherwise ‘standard risk’ ALL, and also may indicate a large tuniour inass where this is not reflected by the height of the circulating WBC.
Red Cell Glutathione Deficiency: Clinical and Biochemical Investigations using Sheep as an Experimental Model System
Authors: Tucker E. M. , Young J. D. , Crowley C. 
Published: March 2008

Summary. The biochemical properties of red cells from normal sheep and sheep with three types of red cell glutathione (GSH)‐deficiency were compared. One deficiency was due to an impaired transport system for amino acids (lesion 1), one was the result of a diminished activity of γ‐glutamyl cysteine synthetase (GC‐S) (lesion 2) and the third was a combined deficiency produced by selective breeding to give animals with both lesions 1 and 2. Under normal husbandry conditions no clinical symptoms were apparent in sheep with lesion 2, but red cells from sheep with lesion 1 and lesions 1+2 showed an increased osmotic fragility, a greater tendency to form Heinz bodies and a shorter potential life span than normal. These deficiencies were not found in tissues other than blood. Normal and GSH‐deficient red cells had the expected low concentrations of 5‐oxoproline.The effects of the toxic agents phenylhydrazine, s‐methylcysteine sulphoxide and nitrite in vivo were measured in sheep of the different types. GSH‐deficient sheep responded earlier and more dramatically than normal sheep, showing greater methaemoglobin formation, and for phenylhydrazine and s‐methylcysteine sulphoxide, more severe anaemia. Sheep with the combined lesions were in general the most susceptible, but even they had the ability to recover from moderately severe oxidative challenge.
Decreased Erythropoiesis: The Origin of the BCG Induced Anaemia in Mice
Authors: Marchal Gilles , Milon Geneviève 
Published: March 2008

Summary.Transient anaemia follows a high dose of viable BCG given intravenously to mice. The anaemia was dependent upon the dose, viability and the route of injection of the BCG. The evidence of an absolute anaemia was based on red cell mass decrease.Serum iron concentration and red cell life span were unchanged in the first 14 d after BCG infection. The erythropoietin level increased 20‐fold. Despite the high level of this hormone and the appearance of increased erythropoiesis in the spleen, the production of erythrocytes was decreased presumably because of a decrease in numbers of erythropoietin‐responsive cells.
Acid α‐naphthyl Acetate Esterase Activity in Nucleated Red Cells of Human Fetal Liver
Authors: Lassila Olli 
Published: March 2008

Summary.Acid α‐naphthyl acetate esterase (ANAE) activity was investigated in nucleated red cells obtained from nine human fetal livers at 9‐24 weeks of gestation. A strong ANAE activity was demonstrated in fetal liver erythroblasts with a staining pattern of a perinuclear ring. Occasionally some polychromato‐philic normoblasts expressed a focal ANAE activity usually observed in human T‐lymphocytes. Some 50‐70% of erythroblasts in human fetal livers showed a ring‐like staining pattern. A slight decrease of ANAE positivity was observed in cells of fetal livers after 17 weeks of gestation.
Origin of Anti‐Thomsen‐Friedenreich (T) and Tn Agglutinins in Man and in White Leghorn Chicks
Authors: Springer Georg F. , Tegtmeyer Herta 
Published: March 2008

Summary. Interest in anti‐Thomsen‐Friedenreich (T) antibodies has increased because of their significance in detection of and their possible interaction with human adenocarcinoma. The origin of anti‐T, which all humans possess, has not been ascertained. We determined here that anti‐T and ‐Tn agglutinins could readily be induced via the physiological intestinal route by an enteric bacterium, E. coli O86, which possesses T and Tn activities.One dose of live E. coli O86 given in the drinking water to germfree chicks, who had no anti‐T and ‐Tn antibodies, resulted, in all birds, in formation of saline agglutinating anti‐T and ‐Tn antibodies as well as those detectable only by indirect agglutination. Antibody specificity was confirmed by adsorption on and elution from homologous human erythrocytes and for anti‐T also by haemagglutination inhibition. In contrast, control chicks raised under ordinary conditions did have anti‐T and ‐Tn prior to feeding E. coli O86.In humans, six diarrhoeic and five healthy infants and the majority of 13 adults investigated were fed killed rather than live E. coli O86. All infants, but one, suffering from diarrhoea showed a significant increase (4‐fold) in anti‐T and/or anti‐Tn antibodies; in some, these antibodies were elicited de novo. All four adults with intestinal lesions had a significant increase of anti‐T and/or ‐Tn subsequent to ingestion of E. coli O86, as did five of nine healthy adults, but to a lesser extent. These findings support the immune nature of demonstrable levels of anti‐T and ‐Tn.