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Red Cells (red + cell)
Terms modified by Red Cells Selected AbstractsThe Reduced Folate Carrier (SLC19A1) c.80G>A Polymorphism is Associated with Red Cell Folate Concentrations Among WomenANNALS OF HUMAN GENETICS, Issue 5 2009Anna Stanis, awska-Sachadyn Summary Low folate status may be a consequence of suboptimal intake, transport or cellular utilization of folate and, together with elevated homocysteine, is a recognized risk factor or marker for several human pathologies. As folate transport across cell membranes is mediated in part by the reduced folate carrier (RFC1), variants within SLC19A1, the gene that encodes RFC1, may influence disease risk via an effect on folate and/or homocysteine levels. The present study was undertaken to assess the association between the SLC19A1 c.80G>A polymorphism and folate/homocysteine concentrations in healthy young adults from Northern Ireland. The SLC19A1 c.80G>A polymorphism was not strongly associated with either serum folate or homocysteine concentrations in either men or women. However, in women, but not in men, this polymorphism explained 5% of the variation in red blood cell (RBC) folate levels (P= 0.02). Relative to women with the SLC19A1 c.80GG genotype, women with the GA and AA genotypes had higher RBC folate concentrations. Consequently, compared to women with the SLC19A1 c.80GA and AA genotypes, women who are homozygous for the 80G allele may be at increased risk of having a child affected with a neural tube defect and of developing pathologies that have been associated with folate insufficiency, such as cardiovascular disease. [source] Quinacrine Enhances Vesicular Stomatitis Virus Inactivation and Diminishes Hemolysis of Dimethylmethylene Blue,phototreated Red Cells,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2002Stephen J. Wagner ABSTRACT Several photodynamic methods for virus inactivation in red blood cell (RBC) suspensions have resulted in unwanted hemolysis during extended 1,6°C storage. To explore the possibility that hemolysis may be mediated by a membrane-bound dye, a molecule similar in structure to yet different in light absorption properties from the photosensitizer was used as an inhibitor for RBC membrane binding in virus photoinactivation and photohemolysis studies. The addition of 500 ,M quinacrine to oxygenated RBC before treatment with 3.6 ,M dimethylmethylene blue (DMMB) and 219 mJ/cm2 red light resulted in an increased extracellular concentration of the sensitizer, increased extracelluar viral inactivation kinetics, and decreased hemolysis during 1,6°C storage without alteration of quinacrine absorption properties. These results collectively suggest that despite its recognized affinity for viral nucleic acid, DMMB also binds to RBC membranes and that the bound dye is, in part, responsible for photoinduced hemolysis. [source] Red cells playing as activated platelets in thalassemia intermediaJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2010P. M. MANNUCCI See also Taher AT, Musallam KM, Karimi M, El-Beshlawy A, Belhoul K, Daar S, Saned M, Cesaretti C, Cappellini MD. Splenectomy and thrombosis: the case of thalassemia intermedia. This issue, pp 2152,8. [source] Splenectomy and thrombosis: the case of thalassemia intermediaJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 10 2010A. T. TAHER See also Mannucci PM. Red cells playing as activated platelets in thalassemia intermedia. This issue, pp 2149,51. Summary.,Background:,Hypercoagulability in splenectomized patients with thalassemia intermedia (TI) has been extensively evaluated. However, clinical and laboratory characteristics of patients who eventually develop overt thromboembolic events (TEE) are poorly studied. Patients/Methods:,Three Groups of TI patients (n = 73 each) were retrospectively identified from a registry involving six centers across the Middle East and Italy: Group I, all splenectomized patients with a documented TEE; Group II, age- and sex-matched splenectomized patients without TEE; and Group III, age- and sex-matched non-splenectomized patients without TEE. Retrieved data included demographics, laboratory parameters, clinical complications, and received treatments that may influence TEE development, and reflected the period prior to TEE occurrence in Group I. Results:,The mean age of Group I patients at development of TEE was 33.1 ± 11.7 years, with a male to female ratio of 33:40. TEE were predominantly venous (95%) while four patients (5%) had documented stroke. Among studied parameters, Group I patients were more likely to have a nucleated red blood cell (NRBC) count , 300 × 106 L,1, a platelet count , 500 × 109 L,1 and evidence of pulmonary hypertension (PHT), or be transfusion naïve. The median time to thrombosis following splenectomy was 8 years. Patients with an NRBC count , 300 × 106 L,1, a platelet count , 500 × 109 L,1, or who were transfusion naive also had a shorter time to thrombosis following splenectomy. Conclusion:,Splenectomized TI patients who will develop TEE may be identified early on by high NRBC and platelet counts, evidence of PHT, and transfusion naivety. [source] The utility of immature reticulocyte fraction as an indicator of erythropoietic response to altitude training in elite cyclistsINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1p2 2010V. S. NADARAJAN Summary Altitude training is sometimes employed by elite endurance athletes to improve their sea level performance. This improvement results from the increased red cell mass consequent upon the boost in erythropoietin (EPO) level that occurs as a response to the relatively hypoxic environment at high altitudes. We measured serum EPO levels together with various red cell and reticulocyte parameters including immature reticulocyte fraction (IRF) in eight national track-endurance cyclists, resident at sea-level, prior to and upon return from an altitude of approximately 1905 m. Reticulocytes and soluble transferrin receptor (sTfR) were significantly increased with reduction in ferritin levels immediately on return from high altitude indicating increased erythropoietic activity. IRF in particular showed a significant peak immediately on return but decline to sub-baseline levels by day 9, and recovery to baseline by day 16. Our results indicate that IRF is a sensitive marker of erythropoietic status in athletes undergoing altitude training and subsequent loss of EPO stimuli on return to sea level. [source] Blocked D phenomenon, a rare condition with Rh D haemolytic disease of newborn , a case reportINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2008P. V. SULOCHANA Summary Accurate Rh testing can be difficult if the red cells are heavily coated with IgG anti D antibodies , a phenomenon called blocked D. Repeatedly, Rh D negative blood group report was obtained in a newborn male baby with severe haemolytic disease and features of kernicterus born to a 2nd gravida B Rh D negative mother. On investigation, the baby was grouped as B Rh D negative by direct grouping, but after elution, D antigen was detected and phenotyped as CcDe. Antibody was identified as anti D. All D antigens of the baby were fully saturated with anti D leaving any antigen to bind with antisera. Direct Coombs test was strongly positive even after three exchange transfusions. The baby also had free antibody apart from the red cell bound and the red cell eluate, gave a titre of 512. The mother was grouped as B Rh D negative and phenotyped as ce. She had IgM and IgG class of anti D with titres 32 and 1024 respectively. She also had IgM anti C (only in neat) and IgG anti-A with a titre of 512. [source] Where will pathogen inactivation have the greatest impact?ISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2007T. Hervig Blood safety has always been a major task in transfusion medicine. A strategy to obtain this aim should include donor education, donor selection, and testing of blood donations. Pathogen inactivation adds another level of safety. In the fractionation industry, pathogen inactivation methods are mandatory. Several countries also use pathogen-inactivated plasma , from pools or single donors. Concerning the cellular blood components, there is still no method available for red cell concentrates, whereas methods for platelet concentrates are available in some countries and others are in the pipeline for commercialization. The efficiency of the ,old' methods to increase blood safety and the costs of the methods seem to be major obstacles for the introduction of the systems. There are also concerns on product quality and loss of volume during the inactivation process. As the importance of pathogen inactivation is largest in countries with blood donors who carry infections it is impossible to protect against, either due to high incidence of the infection or due to shortage of tests, cost will be a major question when pathogen inactivation is considered. Pathogen inactivation of red cell concentrates will also be a necessity. When pathogen inactivation methods are available for all blood components, they will have great impact to protect the patients in countries where a high percentage of the population is infected by agents transmissible through blood transfusion, and in all situations to protect against new pathogens and ,old' pathogens that become more virulent. The total risk of contracting infectious diseases through blood transfusion will probably be important when implementation of new methods for pathogen inactivation is considered. [source] The Energetics of Ion Distribution: The Origin of the Resting Electric Potential of CellsIUBMB LIFE, Issue 5 2002Richard L. Veech Abstract The relation between the energies of ion movement and ATP hydrolysis is unknown in tissues with widely varying electric potentials. Consequently, we measured the concentration of the nine major inorganic ions in the extra- and intracellular phases in heart, liver, and red cells with resting electrical potentials, E N, of -86, -28, and -6 mV, respectively, under six different physiological conditions. We calculated the Nernst electric potential and the energy of ion movement between the phases. We found that the energy of ATP hydrolysis was essentially constant, between -54 and -58 kJ/mol, in all tissues and conditions. In contrast, as E N decreased, the energies of the Na + and K + gradients decreased, with slopes approximating their valence. The difference between the energies of Na + and K + gradients remained constant at 17 kJ/mol, which is approximately one third of the energy of ATP hydrolysis, demonstrating near-equilibrium of the Na +/K + ATPase in all tissues under all conditions. All cations, except K +, were pumped out of cells and all anions, except Cl - in liver and red cell, were pumped into cells. We conclude that the energy of ATP was expressed in Na +/K + ATPase and its linked inorganic ion transporters to create a Gibbs-Donnan near-equilibrium system, an inherent part of which was the electric potential. [source] The effect of storage on the P50 of feline bloodJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2007Chris Wong DVM Abstract Objective: To determine the effect of storage on the P50 of feline hemoglobin. Design: Prospective, in vitro, laboratory study. Subjects: Venous blood from 4 clinically healthy cats. Measurements: Blood was collected into CPDA-1 anticoagulant/preservative and maintained at 4°C for 5 weeks. Measurements were made on Days 0, 2, 4, 7, 14, 21, 28, and 35. The blood samples were equilibrated in a tonometer to gas mixtures containing 2.5%, 4%, 5%, or 8% oxygen, with 5% carbon dioxide balance nitrogen; pH was adjusted to 7.4. Chloride, partial pressure of oxygen, and hemoglobin saturation were measured; P50 was calculated. Results: Chloride decreased from 124.3±2.1 to 88.5±1.9 mEq/L immediately after dilution with CPDA-1, and did not change for the 5 weeks thereafter. The P50 decreased from an average of 35.0±1.2 to between 31 and 32 mmHg after 7 days, and did not change further for 4 weeks thereafter. Conclusions: The decrease in P50 of feline hemoglobin was minor compared with that of blood from species in which 2,3-diphosphoglycerate (2,3-DPG) is a major modifier of hemoglobin affinity for oxygen. The decrease in P50 in the present study was attributed to an initial decrease in chloride and a subsequent loss of modest quantities of red cell 2,3-DPG. [source] Open-label pilot study of folic acid in patients with nonalcoholic steatohepatitisLIVER INTERNATIONAL, Issue 2 2007Phunchai Charatcharoenwitthaya Abstract: Background/Aims: Folate deficiency disturbs hepatic methionine metabolism and promotes the development of steatohepatitis in animal models. Our aims were (1) to determine the safety and efficacy of folic acid treatment in patients with nonalcoholic steatohepatitis (NASH) on changes in liver biochemistries, and (2) to investigate the presence of subclinical folate deficiency in this population. Methods: Patients with biopsy-proven NASH were treated with folic acid 1 mg/day for 6 months. Liver enzymes and adverse events were monitored every 3 months until completion. Results: Ten patients (one male and nine females) with a median age of 54 years were enrolled in this study. At baseline, the median steatosis grade was 2 (range 1,3), the median necroinflammatory grade was 1 (1,3), and the median fibrosis stage was 2 (0,4). The median level of red cell folate was 526 ng/ml (range 99,708); the normal level was 268,616 ng/ml. One compensated cirrhotic patient had folate deficiency. No serious adverse events occurred. After 6 months of therapy, no significant reductions in serum aspartate and alanine aminotransferase levels (60±25 vs. 54±29, P=0.5 and 86±29 vs. 83±42, P=0.6, respectively), were observed. Serum levels of bilirubin, alkaline phosphatase, albumin, and prothrombin time remained in the normal range during treatment in all patients. Conclusion: Six months of therapy with folic acid at a dose of 1 mg/day, although safe and well tolerated, does not lead to a significant biochemical improvement in patients with NASH. In a small number of patients, folate deficiency was present in only a cirrhotic patient. [source] Erythropoietin effect on red cell and plasma volumeTHE JOURNAL OF PHYSIOLOGY, Issue 1 2008Dieter Böning No abstract is available for this article. [source] Combined bezafibrate and medroxyprogesterone acetate have efficacy without haematological toxicity in elderly and relapsed acute myeloid leukaemia (AML)BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2010Jim A. Murray Summary Acute myeloid leukaemia (AML) causes life-threatening deficits of functional blood cells that require management using red cell and platelet transfusion and aggressive treatment of neutropenic infections. Current cytotoxic chemotherapy further worsens the problem of reduced haemopoiesis and two-thirds of patients are too frail to tolerate intensive chemotherapy at all. Median survival amongst these patients remains at <3 months emphasizing the urgent need for anti-AML therapies that do not suppress haemopoiesis. Our laboratory studies showed combined Bezafibrate and Medroxyprogesterone acetate (BaP) had activity against AML without toxicity to normal stem cells. Here we report the safety and efficacy of BaP in 20 patients (19 AML, 1 high-risk myelodysplasia) for whom intensive chemotherapy was not an option. No patient exhibited haematological toxicity from BaP. Eleven patients took BaP alone for >4 weeks. One reverted from high risk myelodysplasia and remains transfusion independent after 201 weeks of therapy. Three AML patients gained major haematological improvements for 22,30 weeks; in one, marrow was available to document a partial AML response. Thus, this trial indicates that BaP therapy has potential for treatment of elderly and relapsed AML. [source] Genetic variation and susceptibility to infection: the red cell and malariaBRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2008D. J. Weatherall Summary There is now convincing evidence that the extremely high frequencies of certain genetic disorders of the red cell involving haemoglobin, the red-cell membrane, or its metabolic pathways reflect relative resistance to malaria over thousands of years. At least some progress has been made towards an understanding of the cellular mechanisms involved, although much remains to be learnt. As well as the extremely valuable information that this field is providing about how exposure to infection has moulded the current structure of the human genome, recent research in this field is starting to provide some valuable new approaches to the better control of parasitic and other infections that remain a major global health problem. [source] Flow cytometry antibody screening using pooled red cells,CYTOMETRY, Issue 2 2010Dong Il Won Abstract Background: For red cell alloantibody screening, the column agglutination technique (CAT) is used extensively, and flow cytometry (FC) screening has recently been demonstrated to be accurate, rapid, and cost effective. We attempted to determine whether the high sensitivity of FC allows pooling of screening red cells, which is generally not an acceptable technique in CAT. Methods: For FC screening, a commercial two-cell screening panel was utilized for the preparation of individual cells (CSi), as well as pooled cells diluted 1 in 2 (CSp), and 1 in 3 (CS1/3). Another panel was pooled from 120 randomly selected group O donors (RSp). Results: Comparing the endpoint titrations of serial dilutions, CS1/3 was found to be one dilution, on the average, less sensitive than CSi. In 33 CAT-positive patient samples, the sensitivities of CSi and CSp did not differ significantly without polyethylene glycol (PEG) (30/33, 26/33, respectively, P = 0.125), although they did differ significantly with PEG (32/33, 25/33, respectively, P = 0.016). The percentages of reactive cells among the total cells from RSp were roughly proportional to the relevant antigen frequencies of the local donors. Conclusions: A trend toward reduced sensitivity was observed using pooled red cells, even via FC. Pooled cells from randomly selected group O donors may be employed as another method by which the characteristics of known antibodies might be assessed. © 2009 Clinical Cytometry Society [source] Erythropoiesis and red cell function in vertebrate embryosEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005R. Baumann Abstract All vertebrate embryos produce a specific erythroid cell population , primitive erythrocytes , early in development. These cells are characterized by expression of the specific embryonic haemoglobins. Many aspects of primitive erythropoiesis and the physiological function of primitive red cells are still enigmatic. Nevertheless, recent years have seen intensive efforts to characterize in greater detail the molecular events underlying the initiation of erythropoiesis in vertebrate embryos. Several key genes have been identified that are necessary for primitive and the subsequent definitive erythropoiesis, which differs in several aspect from primitive erythropoiesis. This review gives in its first part a short overview dealing with comparative aspects of primitive and early definitive erythropoiesis in higher and lower vertebrates and in the second part we discuss the physiological function of primitive red cells based mainly on results from mammalian and avian embryos. [source] Impact of parturition on iron status in nonanaemic iron deficiencyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2003A. Krafft Abstract Background, Iron-deficient nonanaemic parturients risk underdiagnosis as a result of the reliance on postpartum ferritin and haemoglobin as markers of iron status. Ferritin is an acute-phase protein whose levels increase during the inflammatory response, as occurs after delivery. Our aims were to evaluate the impact of parturition on iron status, erythropoiesis and the inflammatory response, and identify the optimal parameters and timing for diagnosing iron deficiency in the presence of postpartum inflammation. Materials and methods, Conventional parameters of iron status, erythropoiesis and the inflammatory response (serum ferritin, serum iron, transferrin saturation, C-reactive protein) were compared with more recent parameters [soluble transferrin receptors (sTfR), hypochromic red cells, reticulocyte indices] within 48 h either side of delivery in 64 iron-deficient nonanaemic women (defined by a prepartum serum ferritin , 15 µg L,1, and a pre- and postpartum haemoglobin of , 11·0 g dL,1 and , 10·0 g dL,1, respectively). Results, Mean sTfR decreased pre to postpartum from 7·3 to 5·8 µg mL,1 (P < 0·01), while mean serum ferritin increased from 9·7 to 16·9 µg L,1 (P < 0·01). Serum ferritin did not correlate with haemoglobin pre or postpartum (r = 0·04, P = 0·7; r = 0·2, P = 0·09), but a correlation persisted postpartum between hypochromic red blood cells and haemoglobin (r = ,0·26; P < 0·05). The percentage of hypochromic red cells remained virtually unchanged pre- and postpartum (4·0% vs. 3·8%; NS). Postpartum mean reticulocyte haemoglobin content (CHr) was 27·1 ± 1·6 pg. Conclusion, Iron status should be tested prepartum, in the absence of an inflammatory response, rather than in the early postpartum. A valuable additional parameter, where available, might be the hypochromic red cell percentage, which is virtually uninfluenced by the inflammatory response. Furthermore, hypochromic red cell percentage, CHr and sTfR can be helpful to differentiate between functional iron deficiency and depleted iron stores. [source] A novel mutation in the last exon of ATRX in a patient with , -thalassemia myelodysplastic syndromeEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2006Daniel B. Costa Abstract:, We describe a patient with acquired alpha-thalassemia myelodysplastic syndrome (ATMDS). A previously healthy 66-year-old man presented with hemoglobin of 9.3 g/dL, mean corpuscular volume 59 fL, and a bone marrow aspirate with increased erythroid precursors and hypolobulated megakaryocytes. Hemoglobin H inclusions were seen in most red cells after 1% brilliant cresyl blue supravital stain of the peripheral blood. At the molecular level, we identified of a novel mutation in the most 3, exon of the ATRX gene (CGA,TGA substitution in codon 2407) resulting in a premature termination codon (p.R2407X). This case provides further evidence for a link between ATRX mutations and ATMDS, and suggests a possible role for the conserved Q-box element in ATRX function. [source] Splenic function and IgM-memory B cells in Crohn's disease patients treated with infliximabINFLAMMATORY BOWEL DISEASES, Issue 5 2008Antonio Di Sabatino MD Abstract Background: Under experimental chronic inflammation, tumor necrosis factor (TNF)-, plays a role in damaging spleen marginal zone. This latter has a crucial function in mounting B cell-dependent immune responses against infections by encapsulated bacteria. In Crohn's disease (CD), a chronic inflammatory disorder where TNF-, is centrally involved, impaired splenic function may increase the susceptibility to bacterial infections. On this basis, we aimed to investigate the influence of anti-TNF therapy on splenic function in CD patients. Methods: Peripheral blood samples were obtained from 15 CD patients before and after treatment with infliximab administered at weeks 0, 2, and 6 at a dose of 5 mg/kg. Counting of erythrocytes with membrane abnormalities (pitted red cells) was used as an indicator of splenic function. Multicolor flow cytometry was performed to analyze circulating B cells. Results: A substantial clinical improvement in 10 of the 15 CD patients was associated with a significant reduction of pitted red cells (from median 6.0% to 3.6%; P < 0.01) after 10 weeks of treatment. In responder patients the improvement of splenic function was accompanied by a parallel increase of circulating IgM-memory B cells (from median 6.9% to 13.3%; P < 0.005). Splenic function was not ameliorated in nonresponder patients. Conclusions: Splenic function improved in CD patients who responded to infliximab and was accompanied by a concomitant restoration of the IgM-memory B cell pool responsible for the protection against encapsulated bacteria. Restoration of splenic function after infliximab treatment is intriguing and requires further investigation. (Inflamm Bowel Dis 2008) [source] Blocked D phenomenon, a rare condition with Rh D haemolytic disease of newborn , a case reportINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2008P. V. SULOCHANA Summary Accurate Rh testing can be difficult if the red cells are heavily coated with IgG anti D antibodies , a phenomenon called blocked D. Repeatedly, Rh D negative blood group report was obtained in a newborn male baby with severe haemolytic disease and features of kernicterus born to a 2nd gravida B Rh D negative mother. On investigation, the baby was grouped as B Rh D negative by direct grouping, but after elution, D antigen was detected and phenotyped as CcDe. Antibody was identified as anti D. All D antigens of the baby were fully saturated with anti D leaving any antigen to bind with antisera. Direct Coombs test was strongly positive even after three exchange transfusions. The baby also had free antibody apart from the red cell bound and the red cell eluate, gave a titre of 512. The mother was grouped as B Rh D negative and phenotyped as ce. She had IgM and IgG class of anti D with titres 32 and 1024 respectively. She also had IgM anti C (only in neat) and IgG anti-A with a titre of 512. [source] An improved method for detecting red cells with hemoglobin H inclusions that does not require glass capillary tubesINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 2 2003D.E. Sabath Summary, -Thalassemia trait is the most common inherited abnormality worldwide. Diagnosis of , -thalassemia trait can be difficult as there are no abnormalities detectable by hemoglobin electrophoresis or high-performance liquid chromatography. Detection of individuals with , -thalassemia trait, particularly the type present in many Asian populations, is important for genetic counseling purposes, because these individuals are at risk for having offspring with hemoglobin Bart's hydrops fetalis, a fatal condition. The best routine diagnostic method to detect individuals with , -thalassemia trait is staining reticulocyte-enriched red cell preparations with brilliant cresyl blue to detect hemoglobin H inclusions. Current methods use centrifugation of microhematocrit tubes to enrich for reticulocytes, which presents a laboratory safety hazard. In this report, we describe an alternative technique to enrich for reticulocytes that does not require glass capillary tubes, but is as effective as the capillary tube method for reticulocyte enrichment and detection of cells containing hemoglobin H inclusions. [source] Patterns of pseudo-reticulocytosis in malaria: fluorescent analysis with the Cell-Dyn® CD4000INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2002C. S. SCOTT This study of Plasmodium falciparum malaria evaluated patterns of fluorescent reticulocyte measurements as determined with the Abbott Cell-Dyn® CD4000. The parasitaemia of positive samples (n=180) ranged from 0.04% to 25.5%, with those (19/180) showing gametocytes having lower parasitaemia levels (mean 0.31%, median 0.2%) compared to those that did not (mean 2.59%, median 0.8%). There was a reasonable association (R2=0.60) between parasitaemia level and CD4000 reticulocyte percentages, although there was overall a small statistical bias towards higher parasitaemia estimates determined microscopically. Consistently high immature reticulocyte fraction (IRF) values of >0.5 were observed in cases with a parasitaemia exceeding 5%, while samples with lower parasitaemia levels showed more variable IRF values. Visual examination of CD4000 reticulocyte histograms revealed that 81/100 malaria-positive samples with an IRF above 0.5 showed the presence of a fluorescent population `spike' consistent with the staining of intracellular malaria parasites. Only three of the 80 malaria-positive samples with an IRF below 0.5, and none of the 237 malaria-negative samples, showed this histogram pattern. These observations indicate that samples with malaria parasites give erroneously high CD4000 reticulocyte estimates that essentially comprise the sum total of true reticulocytes and parasite-infected red cells (pseudo-reticulocytes). This limitation is common to all automated reticulocyte procedures but recognizing the differences between homogenous staining parasitized red cells and heterogeneous staining reticulocytes has potential applications in monitoring parasitaemia levels both at patient presentation and during subsequent treatment. [source] Respiratory changes in human red cellsINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2001G. Aliberti To investigate physiological respiratory changes in human red cells, we measured automated red cell parameters in samples from the pulmonary and radial arteries of 86 patients undergoing aorto-coronary bypass and from the pulmonary artery and the aorta in 23 patients. Our results showed higher mean corpuscular volume (88.53 ± 5.06 fl vs. 88.12 ± 4.94 fl, P < 0.000001), haematocrit (0.369 ± 0.039 vs. 0.367 ± 0.038, P < 0.0005), red cell distribution width (43.38 ± 4.16 vs. 43.04 ± 4.05 fl, P < 0.000001) and a lower mean corpuscular haemoglobin concentration (338.3 ± 15.9 vs. 339.9 ± 16.8 g/l, P < 0.005) in pulmonary arterial as compared to radial arterial blood. There were no differences with respect to haemoglobin concentration, red blood cell count, or mean corpuscular haemoglobin. Similar differences were observed between pulmonary arterial and aortic blood. Our results suggest cyclic respiratory modifications of red cell parameters attributable to the CO2 Jacobs,Stewart cycle. [source] Flow cytometric method for simultaneous assay of foetal haemoglobin containing red cells, reticulocytes and foetal haemoglobin containing reticulocytesINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2001Y. Mundee Level of foetal haemoglobin (HbF) containing red cells (F cells) is a parameter for monitoring sickle cell anaemia (SS) patients undergoing treatment with HbF modulating drugs (including hydroxyurea (HU)). One convenient technique for F cell assay is flow cytometry. A flow cytometric method for the simultaneous assay of F cells, reticulocytes and HbF-containing reticulocytes (F reticulocytes) is described in this paper. These three parameters can be obtained within 2 h using double colour staining flow cytometry. Glutaraldehyde fixation, Triton X-100 permeabilization, monoclonal antibody to HbF Tri-colour® conjugate (MoAb-HbF-TC; deep-red fluorescence) immuno-staining and thiazole orange (TO; green fluorescence) are employed. The red cell gate was set on forward scatter (FSC) and logarithmic side scatter (logSSC) for 50 000 cells on the flow cytometer. Fluorescent signals were acquired from fluorescent channel 1 (FL1; green) and (FL4; deep-red). Coefficient of variation percent (%CVs) of intra- and inter-assay were less than 9% and 15%, respectively. EDTA, citrate, heparin and CTAD anticoagulants are all suitable; the samples can be stored at 4°C for up to 6 days. The method is a simple, rapid, convenient, reproducible and useful way of determining F cell, reticulocyte and F reticulocyte levels in sickle cell and thalassaemic patients. [source] Automated counting of white and red blood cells in the cerebrospinal fluidINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2000M.W. Aune Summary The objective of this study was to examine to what extent the automated method of the Bayer H*2 instrument could replace the visual counting of white and red blood cells in cerebrospinal fluid. The number of white blood cells as well as the percentage of mononuclear and polymorphonuclear cells were counted in the ,Baso channel' (Research screen 3) whereas the number of red cells were registered as the ,R-count' (Research screen 1). All automated cell counts were compared to visual estimates. The automated count yielded reliable results down to 5 × 106 white blood cells/l and 5 × 108 red blood cells/l. In some samples ,noise' was present in the Baso channel. A correct white blood cell count could then be obtained by counting the cells directly as dots on the screen. It was possible to differentiate between polymorphnuclear cells and mononuclear cells at all WBC concentrations. The automated counting of cerebrospinal fluid can be performed without changing thresholds or sample volumes of the instrument. Thus, in the routine practice it will be possible to alternate between automated counting of whole blood samples and cerebrospinal fluid samples. [source] Blood group antigens and immune responses,detailed knowledge is necessary to prevent immunization and to follow up immunized individualsISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue n1 2010A. Husebekk Background The immune system is educated to detect and react with foreign antigens and to tolerate self-antigen. Transfusion of blood cells and plasma and pregnancies challenge the immune system by the introduction of foreign antigens. The antigens may cause an immune response, but in many instances this is not the case and the individual is not immunised after exposure of blood group antigens. Aims The aim of the presentation is to dissect some immune responses to blood group antigens in order to understand the mechanism of immunisation. Methods The results of immune responses to blood group antigens can be detected by the presence of antibodies to the antigens. If the antibodies are of IgG class, the activated B cells have received help from antigen specific T cells. Both antibodies, B cells and T cells can be isolated from immunised individuals and studied in the laboratory. Also B-cell receptors and T-cell receptors as well as MHC molecules on antigen presenting cells can be studied and models of the immune synapses can be created in vitro. Results The most classic immune responses in transfusion medicine and in incompatible pregnancies are immune responses to the RhD antigen on red cells, HLA class I molecules on white cells and platelets and human platelet antigens. The nature of these antigens are different; RhD antigens are part of a large complex, present on red cells from RhD positive individuals and completely lacking on red cells from RhD negative individuals. It is likely that many peptides derived from this antigen complex may stimulate T cells and B cells. HLA antigens are highly polymorphic and the antigens are known to induce strong alloimmune responses. The HPA antigens are created by one amino acid difference in allotypes based on a single nucleotide polymorphism at the genetic level. HPA 1a induce immune responses in 10% of HPA 1b homozygote pregnant women. The result of these immune responses is destruction of blood cells with clinical consequences connected to the effect of transfusions or the outcome of pregnancies. Summary/Conclusions Even though there is emerging knowledge about the immune responses to some of the blood group antigens, more information must be gained in order to understand the complete picture. The action of the innate immune response initiating the adaptive immune response to blood group antigens is not well understood. A detailed understanding of both the innate ad the adaptive part of the immune response is necessary to identify individuals at risk for immunisation and to prevent immunisation to blood group antigens. [source] A cornerstone for adequate supply of safe bloodISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2006M. Y. Zhu Blood safety and timely adequate supply have significant impacts not only on healthcare service, but also the socio-economic development and political stability of a country. However, until a decade ago the importance has not been seriously taken in the country. Distinct blood programme and safety strategy were not always available. In certain regions of the country the supervision to establishments involved in blood collection, processing and transfusion was neither strict nor sufficient. During the early period of 1990, HIV was transmitted among plasma-apheresis donors in two central provinces. The relevant plasma-apheresis centres, in which plasma is collected solely as source materials for fractionation, were accused for wrongdoings including not performing HIV screening, and mixing red cells from different donors with same blood types before back infusion. [source] The Energetics of Ion Distribution: The Origin of the Resting Electric Potential of CellsIUBMB LIFE, Issue 5 2002Richard L. Veech Abstract The relation between the energies of ion movement and ATP hydrolysis is unknown in tissues with widely varying electric potentials. Consequently, we measured the concentration of the nine major inorganic ions in the extra- and intracellular phases in heart, liver, and red cells with resting electrical potentials, E N, of -86, -28, and -6 mV, respectively, under six different physiological conditions. We calculated the Nernst electric potential and the energy of ion movement between the phases. We found that the energy of ATP hydrolysis was essentially constant, between -54 and -58 kJ/mol, in all tissues and conditions. In contrast, as E N decreased, the energies of the Na + and K + gradients decreased, with slopes approximating their valence. The difference between the energies of Na + and K + gradients remained constant at 17 kJ/mol, which is approximately one third of the energy of ATP hydrolysis, demonstrating near-equilibrium of the Na +/K + ATPase in all tissues under all conditions. All cations, except K +, were pumped out of cells and all anions, except Cl - in liver and red cell, were pumped into cells. We conclude that the energy of ATP was expressed in Na +/K + ATPase and its linked inorganic ion transporters to create a Gibbs-Donnan near-equilibrium system, an inherent part of which was the electric potential. [source] Red cell exchange transfusion for babesiosis in Rhode IslandJOURNAL OF CLINICAL APHERESIS, Issue 3 2009Joshua Spaete Abstract We report four cases of clinically severe tick borne babesiosis treated with chemotherapy and adjunctive red cell exchange (RCE) at two Rhode Island hospitals from 2004 to 2007. All RCE procedures were performed using a Cobe Spectra device and were well tolerated without complications. The volume of allogeneic red cells used in the exchange was determined using the algorithm in the apheresis device with the input variables of preprocedure hematocrit, weight, height, an assumed allogeneic red cell hematocrit of 55 and a desired post procedure hematocrit of 27. The preprocedure level of parasitemia varied between 2.4% and 24% and the postprocedure level of parasitemia between 0.4 and 5.5% with an average overall percent reduction in parasitemia of 74%. Retrospectively, application of a new formula to calculate red cell mass appeared to correlate better with the percent reduction in parasitemia. Previous reports of RCE in babesiosis were reviewed. The reported reduction in parasitemia varied from 50% to >90%. Although a preprocedure level of parasitemia of 10% is sometimes used as a threshold for RCE in clinically severe babesiosis, this threshold does not have a firm empirical basis. No postprocedure desired level of parasitemia is indicated nor the mass of allogeneic red cells needed to achieve such a level. We conclude that current estimates of the dose of allogeneic red cells used in RCE are probably inaccurate, advocate a new formula to estimate this dose and suggest that a 90% reduction in parasitemia should be the minimally desired target of RCE in babesiosis. J. Clin. Apheresis, 2009. © 2009 Wiley-Liss, Inc. [source] Living without aprotinin: the results of a 5-year blood saving program in cardiac surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2009M. RANUCCI Background: After 20 years of regular use in cardiac surgery patients, aprotinin has recently been withdrawn from the market due to many concerns about its safety. For a number of reasons aprotinin has not been available in Italy since 1998. The present study presents an aprotinin-free treatment protocol applied at our institution during the last 5 years, and aims to verify the results of this protocol in terms of allogeneic blood product transfusions, postoperative blood loss and surgical re-exploration rate. Methods: Retrospective study on 7988 consecutive patients who underwent cardiac surgery during the years 2003,2007. All the patients received specific hemostasis/coagulation management based on (a) routine use of tranexamic acid, (b) heparin dose,response monitoring, thromboelastography, platelet (PLT) function analysis in a select population of patients, and (c) use of fresh frozen plasma (FFP), PLTs, and desmopressin according to the hemostasis/coagulation profile. Data retrieved from the institutional database were quantity of packed red cells (PRCs), FFP, PLT transfusion rate, blood loss in the first 12 postoperative hours, and surgical re-exploration rate. Results: PRCs were transfused in 40.4% of patients (with higher rates for selected high-risk subpopulations), FFP in 12.9% and PLTs in 2.6%. Surgical re-exploration rate was 3.7%. With respect to historical controls, a significant reduction of PRCs and FFP transfusions was obtained using closed circuits, point of care coagulation tests, and combination of the two. Conclusion: This aprotinin-free blood saving program is an effective strategy for allogeneic blood products transfusion containment. [source] Core-shell CdS/Cd(OH)2 quantum dots: synthesis and bioconjugation to target red cells antigensJOURNAL OF MICROSCOPY, Issue 3 2005P. M. ALBUQUERQUE DE FARIAS Summary We report a new and efficient methodology of labelling red blood cells, in order to investigate the expression of anti-A antigen, employing luminescent semiconductor nanocrystals. Highly luminescent and stable core-shell cadmium sulphide/cadmium hydroxide [CdS/CdS(OH)2] colloidal particles were obtained in the nanometre size range. The surface of these particles was characterized by using a monoclonal anti-A antibody via a one-step glutaraldehyde cross-linking procedure, followed by conjugation of the particles to red cells of blood groups A+, and O+. Laser scanning confocal microscopy images indicated that after conjugation for 30 min, A+ and erythrocytes presented different patterns of dual bright emission whereas the O+ group cells showed no emission. We suggest that this labelling procedure may be applied as a quantitative tool to investigate the distribution and expression of alloantigen in red blood cells. [source] | |||||||||||||||||||||||||||||||