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RBC
Terms modified by RBC Selected AbstractsDecreased red blood cell aggregation subsequent to improved glycaemic control in Type 2 diabetes mellitusDIABETIC MEDICINE, Issue 4 2003B. Chong-Martinez Abstract Aims Reports of rheological changes following intensification of metabolic control are limited and not concordant. The present study was designed to test the hypothesis that intensification of management of Type 2 diabetes (T2DM) with diet, exercise and insulin improves haemorheological behaviour by reducing red blood cell (RBC) aggregation. Methods Blood was sampled from 55 subjects before and following 14 ± 3 weeks of intensified management. RBC aggregation was measured in vitro for cells in plasma or in an aggregating 70 kD dextran solution. Plasma viscosity and whole blood viscosity were also measured. Results During treatment, fasting glucose fell 27%, HbA1c fell 21%, and serum triglycerides and total cholesterol fell 28% and 12%, respectively (P < 0.0001 for each). The extent and strength of RBC aggregation in plasma fell by 10,13% (P < 0.002). Similar decreases of RBC aggregation were seen for cells suspended in dextran (P < 0.002). Plasma viscosity decreased by 3% (P < 0.02) and high shear blood viscosity by 6,7% (P < 0.0001). Changes of RBC aggregation in plasma and in dextran were significantly correlated, supporting a cellular rather than a plasmatic origin for these changes. However, there were no significant correlations between RBC aggregation changes and changes of fasting glucose, HbA1c, serum triglycerides, serum cholesterol, or plasma fibrinogen. Conclusions Intensified metabolic control results in a reduction of RBC aggregation that appears to be intrinsic to RBC. Since increased RBC aggregation can impair microcirculatory flow, it is possible that haemorheological factors may contribute to the reduction of microvascular complications resulting from improved metabolic control in T2DM. [source] 2-DE using hemi-fluorinated surfactantsELECTROPHORESIS, Issue 14 2007Mireille Starita-Geribaldi Dr. Abstract The synthesis of hemi-fluorinated zwitterionic surfactants was realized and assessed for 2-DE, a powerful separation method for proteomic analysis. These new fluorinated amidosulfobetaine (FASB- p,m) were compared to their hydrocarbon counterparts amidosulfobetaine (ASB- n) characterized by a hydrophilic polar head, a hydrophobic and lipophilic tail, and an amido group as connector. The tail of these FASB surfactants was in part fluorinated resulting in the modulation of its lipophilicity (or oleophobicity). Their effect on the red blood cell (RBC) membrane showed a specific solubilization depending on the length of the hydrophobic part. A large number of polypeptide spots appeared in the 2-DE patterns by using FASB- p,m. The oleophobic character of these surfactants was confirmed by the fact that Band 3, a highly hydrophobic transmembrane protein, was not solubilized by these fluorinated structures. The corresponding pellet was very rich in Band 3 and could then be solubilized by using a strong detergent such as amidosulfobetaine with an alkyl tail containing 14 carbon atoms (ASB-14). Thus, these hemi-fluorinated surfactants appeared as powerful tools when used at the first step of a two-step solubilization strategy using a hydrocarbon homologous surfactant in the second step. [source] Cholesterol-rich membrane coatings for interaction studies in capillary electrophoresis: Application to red blood cell lipid extractsELECTROPHORESIS, Issue 20 2006Maria V. Lindén Abstract The purpose was to develop a stable biological membrane coating for CE useful for membrane interaction studies. The effect of cholesterol (chol) on the stability of dipalmitoylphosphatidylcholine (DPPC) and sphingomyelin (SM) coatings was studied. In addition, a fused-silica capillary for CE was coated with human red blood cell (RBC) ghost lipids. Liposomes prepared of DPPC/SM with and without chol or RBC ghost lipids were flushed through the capillary and the stability of the coating was measured electrophoretically. Similar mixtures of DPPC/SM with and without chol were further studied by differential scanning calorimetry. The presence of phosphatidylcholine as a basic component in the coating solution of DPPC/SM/chol was found to be essential to achieve a good and stable coating. The results also confirmed the stability of coatings obtained with solutions of DPPC with 0,30,mol% of chol and SM in different ratios, which more closely resemble natural membranes. Finally, the electrophoretic measurements revealed that a stable coating is formed when capillaries are coated with liposomes of RBC ghost lipids. [source] New drug combinations for the treatment of murine AIDS and macrophage protectionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2001A. Fraternale The failure of highly active antiretroviral therapies (HAART) is mainly due to the existence of latent infected reservoirs, such as macrophages and resting CD4+ T cells. In this paper, we report the results that we obtained in a murine model of AIDS by alternating the administration of the lympholitic drug 2-Fluoro-ara-AMP (Fludarabine) to eliminate the infected cells, with that of Azidothymidine (AZT) plus reduced glutathione (GSH) encapsulated in erythrocytes, to protect lymphocytes and macrophages not yet infected, respectively. Two groups of infected mice were treated as follows: one group was treated by alternating the administration of Fludarabine and AZT (treatment A), while the other group received the same treatment plus GSH-loaded erythrocytes given with AZT (treatment A + L,RBC). Fludarabine was administered intraperitoneally, AZT in the drinking water and GSH was encapsulated in erythrocytes by a procedure of hypotonic dialysis and isotonic resealing. The results obtained show that GSH-loaded erythrocytes provide additive effects in all the parameters examined. Alternation of a lympholitic drug and antiretroviral drug is effective in reducing the progression of murine AIDS. Addition of a system to protect macrophages provides additive effects in almost all the parameters considered, confirming that combination therapies aimed at protecting different infectable cell compartments are better than treatments protecting mainly lymphocytes. [source] Haematological reference values in Spanish adolescents: the AVENA studyEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2009Javier Romeo Abstract Objectives:, To provide reference values for haematological indices in Spanish adolescents according to age and gender. Methods:, A cross sectional study conducted in five Spanish cities was performed. Blood was drawn from a representative sample of 581 adolescents with age ranging from 13 to 17,18.5 yr. Age- and gender-specific means, standard deviations and percentiles were determined for the following parameters: total red blood cell counts (RBC), haemoglobin concentration (Hb), haematocrit percentage (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red cell distribution width and total white blood cell (WBC) counts as well as counts and percentage of neutrophils, lymphocytes, monocytes, eosinophils and basophils; platelet count (PLT), mean platelet volume and plateletcrit percentage. Results:, Younger male subjects presented lower RBC, Hb, Hct and MCV means that their older counterpart. By contrast these differences were not observed in female subjects. As expected, RBC, Hb and Hct mean values in males were found significantly higher than in girls for all studied age groups. No significant differences were observed in WBC by age and gender. PLT values gradually decreased with age, except for females aged 17,18.5 yr. Conclusion:, The present study provides reference data on the distribution of haematological indices of Spanish adolescents. These data can be useful biomarkers of the nutritional status in adolescents. [source] Oxidative stress in red blood cells, platelets and polymorphonuclear leukocytes from patients with myelodysplastic syndromeEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 6 2007Hussam Ghoti Abstract Low-risk myelodysplastic syndrome (MDS) is characterized by cytopenia, mainly anemia, because of ineffective hematopoiesis. Some of the patients with ineffective erythropoiesis, with or without ring sideroblasts in their bone marrow, develop severe anemia requiring frequent blood transfusions and consequently develop iron overload. Excess free iron in cells catalyses the generation of reactive oxygen species (ROS) that cause cell and tissue damage. Using flow cytometry techniques, we compared the oxidative status of red blood cells (RBC), platelets and neutrophils in 14 MDS patients with those of normal donors. The results show that ROS were higher while reduced glutathione (GSH) was lower in their RBC and platelets compared with normal cells. In neutrophils, no difference was found in ROS, while the GSH levels were lower. A correlation (r = 0.6) was found between serum ferritin levels of the patients and the ROS in their RBC and platelets. The oxidative stress was ameliorated by a short incubation with the iron-chelators, the deferrioxamine and deferiprone or with antioxidants such as N -acetylcysteine, suggesting that MDS patients might benefit from treatment with iron-chelators and antioxidants. [source] Optical tweezers for measuring red blood cell elasticity: application to the study of drug response in sickle cell diseaseEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 4 2003M. M. Brandão Abstract: The deformability of erythrocytes is a critical determinant of blood flow in microcirculation. By capturing red blood cells (RBC) with optical tweezers and dragging them through a viscous fluid we were able to measure their overall elasticity. We measured, and compared, the RBC deformability of 15 homozygous patients (HbSS) including five patients taking hydroxyurea (HU) for at least 6 months (HbSS/HU), 10 subjects with sickle cell trait (HbAS) and 35 normal controls. Our results showed that the RBC deformability was significantly lower in haemoglobin S (HbS) subjects (HbSS and HbAS), except for HbSS/HU cells, whose deformability was similar to the normal controls. Our data showed that the laser optical tweezers technique is able to detect differences in HbS RBC from subjects taking HU, and to differentiate RBC from normal controls and HbAS, indicating that this is a very sensitive method and can be applied for detection of drug-response in sickle cell disease. [source] Regulatory T cells in human geohelminth infection suppress immune responses to BCG and Plasmodium falciparumEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2010Linda J. Wammes Abstract Chronic helminth infections induce T-cell hyporesponsiveness, which may affect immune responses to other pathogens or to vaccines. This study investigates the influence of Treg activity on proliferation and cytokine responses to BCG and Plasmodium falciparum -parasitized RBC in Indonesian schoolchildren. Geohelminth-infected children's in vitro T-cell proliferation to either BCG or pRBC was reduced compared to that of uninfected children. Although the frequency of CD4+CD25hiFOXP3+ T cells was similar regardless of infection status, the suppressive activity differed between geohelminth-infected and geohelminth-uninfected groups: Ag-specific proliferative responses increased upon CD4+CD25hi T-cell depletion in geohelminth-infected subjects only. In addition, IFN-, production in response to both BCG and parasitized RBC was increased after removal of CD4+CD25hi T cells. These data demonstrate that geohelminth-associated Treg influence immune responses to bystander Ag of mycobacteria and plasmodia. Geohelminth-induced immune modulation may have important consequences for co-endemic infections and vaccine trials. [source] Multiple functions of human T cells generated by experimental malaria challengeEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2009Stephen M. Todryk Abstract Protective immunity generated following malaria infection may be comprised of Ab or T cells against malaria Ag of different stages; however, the short-lived immunity that is observed suggests deficiency in immune memory or regulatory activity. In this study, cellular immune responses were investigated in individuals receiving Plasmodium falciparum sporozoite challenge by the natural (mosquito bite) route as part of a malaria vaccine efficacy trial. Parasitemia, monitored by blood film microscopy and PCR, was subsequently cleared with drugs. All individuals demonstrated stable IFN-,, IL-2 and IL-4 ex vivo ELISPOT effector responses against P. falciparum -infected RBC (iRBC) Ag, 28 and 90,days after challenge. However, infected RBC-specific central memory responses, as measured by IFN-, cultured ELISPOT, were low and unstable over time, despite CD4+ T cells being highly proliferative by CFSE dilution, and showed an inverse relationship to parasite density. In support of the observation of poor memory, co-culture experiments showed reduced responses to common recall Ag, indicating malaria-specific regulatory activity. This activity could not be accounted for by the expression of IL-10, TGF-,, FOXP3 or CTLA-4, but proliferating T cells expressed high levels of CD95, indicating a pro-apoptotic phenotype. Lastly, there was an inverse relationship between FOXP3 expression, when measured 10 days after challenge, and ex vivo IFN-, measured more than 100 days later. This study shows that malaria infection elicits specific Th1 and Th2 effector cells, but concomitant weak central memory and regulatory activity, which may help to explain the short-lived immunity observed. [source] Effect of irradiation type (LED or QTH) on photo-activated composite shrinkage strain kinetics, temperature rise, and hardnessEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 6 2002Norbert Hofmann This study compares commercially available light-emitting diode (LED) lights with a quartz tungsten halogen (QTH) unit for photo-activating resin-based composites (RBC). Shrinkage strain kinetics and temperature within the RBC were measured simultaneously using the ,deflecting disc technique' and a thermocouple. Surface hardness (Knoop) at the bottom of 1.5-mm thick RBC specimens was measured 24 h after irradiation to indicate degree of cure. Irradiation was performed for 40 s using either the continuous or the ramp-curing mode of a QTH and a LED light (800 mW cm,2 and 320 mW cm,2, respectively) or the continuous mode of a lower intensity LED light (160,mW cm,2). For Herculite XRV and Filtek Z250 (both containing only camphoroquinone as a photo-initiator) the QTH and the stronger LED light produced similar hardness, while in the case of Definite (containing an additional photo-activator absorbing at lower wavelength) lower hardness was observed after LED irradiation. The temperature rise during polymerization and heating from radiation were lower with LED compared to QTH curing. The fastest increase of polymerization contraction was observed after QTH continuous irradiation, followed by the stronger and the weaker LED light in the continuous mode. Ramp curing decreased contraction speed even more. Shrinkage strain after 60 min was greater following QTH irradiation compared with both LED units (Herculite, Definite) or with the weaker LED light (Z250). [source] Red Cell Pulmonary Transit Times Through the Healthy Human LungEXPERIMENTAL PHYSIOLOGY, Issue 2 2003G. S. Zavorsky It has previously been postulated that rapid red cell capillary transit through the human lung plays a role in the mechanism of diffusion limitation in some endurance athletes. Methodological limitations currently prevent researchers from directly measuring pulmonary capillary transit times in humans during exercise; however, first pass radionuclide cardiography allows direct measurement of red blood cell (RBC) transit times through the whole lung at various exercise intensities. We examined the relationship between mean whole lung red cell pulmonary transit times (cardiopulmonary transit times or CPTT) and different levels of flow in 88 healthy humans (76 males, 12 females) from several studies (mean age 31 years). The pooled data suggest that the relationship between CPTT and cardiac index (CI), beginning at rest and progressing through to maximum exercise demonstrates that CPTT reaches its minimum value when CI is about 8.1 l m2 min,1 (2.5-3 times the CI value at rest), and does not significantly change with further increases in CI. Cardiopulmonary blood volume (CPBV) index also does not change significantly until CI reaches 2.5 to 3 times the CI value at rest and then increases roughly linearly after that point. Consequently, the systematic increase in CPBV index with increasing pulmonary blood flow between 8.1 and 20 l m2 min,1 displays an adaptive response of the cardiopulmonary system by augmenting CPBV (and perhaps pulmonary capillary blood volume through distension and recruitment) to offset the reduction in CPTT, as no significant difference in mean CPTT is observed between these levels of flow (P > 0.05). Therefore, these data demonstrate that CPBV does not reach maximum capacity during strenuous or maximum exercise. This does not support the principle of quarter-power allometric scaling for flow when explaining modifications during exercise. Therefore, we speculate that the observed relationships between CPTT, CBPV index and flow may prevent mean CPTT (and perhaps mean pulmonary capillary transit times) from decreasing below the threshold time required for oxygenation. [source] Interpreting temporal variation in omnivore foraging ecology via stable isotope modellingFUNCTIONAL ECOLOGY, Issue 4 2009Carolyn M. Kurle Summary 1The use of stable carbon (C) and nitrogen (N) isotopes (,15N and ,13C, respectively) to delineate trophic patterns in wild animals is common in ecology. Their utility as a tool for interpreting temporal change in diet due to seasonality, migration, climate change or species invasion depends upon an understanding of the rates at which stable isotopes incorporate from diet into animal tissues. To best determine the foraging habits of invasive rats on island ecosystems and to illuminate the interpretation of wild omnivore diets in general, I investigated isotope incorporation rates of C and N in fur, liver, kidney, muscle, serum and red blood cells (RBC) from captive rats raised on a diet with low ,15N and ,13C values and switched to a diet with higher ,15N and ,13C values. 2I used the reaction progress variable method (RPVM), a linear fitting procedure, to estimate whether a single or multiple compartment model best described isotope turnover in each tissue. Small sample Akaike Information criterion (AICc) model comparison analysis indicated that 1 compartment nonlinear models best described isotope incorporation rates for liver, RBC, muscle, and fur, whereas 2 compartment nonlinear models were best for serum and kidney. 3I compared isotope incorporation rates using the RPVM versus nonlinear models. There were no differences in estimated isotope retention times between the model types for serum and kidney (except for N turnover in kidney from females). Isotope incorporation took longer when estimated using the nonlinear models for RBC, muscle, and fur, but was shorter for liver tissue. 4There were no statistical differences between sexes in the isotope incorporation rates. I also found that N and C isotope incorporation rates were decoupled for liver, with C incorporating into liver tissue faster than N. 5The data demonstrate the utility of analysing isotope ratios of multiple tissues from a single animal when estimating temporal variation in mammalian foraging ecology. [source] Helicobacter pylori and Early Duodenal Ulcer Status Post-Treatment: a ReviewHELICOBACTER, Issue 2 2001Joette M. Meyer Abstract Background. Data submitted to the FDA were reviewed to analyze the relationship between Helicobacter pylori infection and the incidence of early duodenal ulcers, within 6 weeks, following treatment. Materials and Methods. Retrospective analyzes were performed on data from three H. pylori development programs submitted to the FDA: ranitidine-bismuth-citrate (RBC), lansoprazole (L) and omeprazole (O). Efficacy assessments for the RBC, L and O programs were made at end of a 4-week treatment period, 4,6 weeks following the end of a 14-day treatment period, and 4 weeks following the end of a 4-week treatment period, respectively. Results. Overall, there was a 15%, 21% and 23% decrease in the number of patients in the RBC, L and O programs, respectively, with ulcers among H. pylori cleared/eradicated patients post-treatment compared with patients with persistent infection. Among patients who did not have cleared/eradicated H. pylori in the RBC and O programs, where antisecretory agents were continued beyond the antimicrobial treatment period, the number of ulcers was lower in the antisecretory plus antimicrobial subgroups compared with the antimicrobial alone subgroups (37% vs. 46% for RBC and 33% vs. 42% for O). Among patients with cleared/eradicated H. pylori, the number of patients with ulcers in the antimicrobial alone subgroups and antisecretory plus antimicrobial subgroups were similar within each program. Antimicrobials alone had significantly lower rates of ulcers among patients with cleared/eradicated H. pylori as compared with patients without clearance/eradication. Conclusions. The early incidence of duodenal ulcers is significantly decreased in patients with H. pylori clearance/eradication. [source] Congenital dyserythropoietic anemia type II (CDAII) is caused by mutations in the SEC23B gene,HUMAN MUTATION, Issue 9 2009Paola Bianchi Abstract Congenital dyserythropoietic anemia type II (CDAII) is an autosomal recessive disease characterized by ineffective erythropoiesis, hemolysis, erythroblast morphological abnormalities, and hypoglycosylation of some red blood cell (RBC) membrane proteins. Recent studies indicated that CDAII is caused by a defect disturbing Golgi processing in erythroblasts. A linkage analysis located a candidate region on chromosome 20, termed the CDAN2 locus, in the majority of CDAII patients but the aberrant gene has not so far been elucidated. We used a proteomic-genomic approach to identify SEC23B as the candidate gene for CDAII by matching the recently published data on the cytoplasmic proteome of human RBCs with the chromosomic localization of CDAN2 locus. Sequencing analysis of SEC23B gene in 13 CDAII patients from 10 families revealed 12 different mutations: six missense (c.40C>T, c.325G>A, c.1043A>C, c.1489C>T, c.1808C>T, and c.2101C>T), two frameshift (c.428_428delAinsCG and c.1821delT), one splicing (c.689+1G>A), and three nonsense (c.568C>T, c.649C>T, and c.1660C>T). Mutations c.40C>T and c.325G>A were detected in unrelated patients. SEC23B is a member of the Sec23/Sec24 family, a component of the COPII coat protein complex involved in protein transport through membrane vesicles. Abnormalities in this gene are likely to disturb endoplasmic reticulum (ER)-to-Golgi trafficking, affecting different glycosylation pathways and ultimately accounting for the cellular phenotype observed in CDAII. Hum Mutat 30:1,7, 2009. © 2009 Wiley-Liss, Inc. [source] Increased strength of erythrocyte aggregates in blood of patients with inflammatory bowel diseaseINFLAMMATORY BOWEL DISEASES, Issue 5 2009Nitsan Maharshak MD Abstract Background: Increased strength of red blood cell (RBC) aggregates are present during the acute inflammatory response and contribute to erythrocyte aggregation and may lead to microvascular dysfunction. Inflammatory bowel diseases (IBDs) are characterized by damage to the bowel wall. This damage may be at least partially attributed to microvascular ischemia caused by enhanced erythrocyte aggregation. The aim of this study was to evaluate the strength of RBC aggregates in the blood of patients with IBD. Methods: The strengths of RBC aggregates were characterized by integrative RBC aggregation parameters, determined by measuring of RBC aggregation as a function of shear stress. The results are represented as the area under the curve (AUC) of aggregate size plotted against shear stress. For each patient, dynamic aggregation and disaggregation of RBC were recorded and analyzed according to the RBC aggregate size distribution at the different shear stresses. Aggregation indices were correlated with disease activity and inflammatory biomarkers. Results: We examined 53 IBD patients and 63 controls. IBD patients had significantly elevated concentrations of inflammation-sensitive proteins and aggregation parameters. The strength of large aggregates, represented by AUC for large fraction aggregates, among patients (15.2 ± 18.6) was double that of controls (7 ± 10.9) (P = 0.006). The strength of large aggregates correlated with disease activity (r = 0.340; P < 0.001) with concentration of fibrinogen (r = 0.575; P < 0.001) and with concentration of high sensitivity C-reactive protein (r = 0.386; P < 0.001). Conclusions: The strength of RBC aggregates is increased in patients with IBD and correlates with the intensity of the acute phase response. This could contribute to bowel damage in these diseases. (Inflamm Bowel Dis 2009) [source] TECHNOLOGY SHOCKS AND ROBUST SIGN RESTRICTIONS IN A EURO AREA SVAR,INTERNATIONAL ECONOMIC REVIEW, Issue 3 2009Gert Peersman We use a model-based identification strategy to estimate the impact of technology shocks on hours worked and employment in the euro area. The sign restrictions applied in the vector autoregression (VAR) analysis are consistent with a large class of dynamic stochastic general equilibrium (DSGE) models and are robust to parameter uncertainty. The results are in line with the conventional Real Business Cycle (RBC) interpretation that hours worked rise as a result of a positive technology shock. By comparing the sign restrictions method to the long-run restriction approach of Galí (Quaterly Journal of Economics,(1992) 709,38), we show that the results do not depend on the stochastic specification of the hours worked series or the data sample but only on the identification scheme. [source] Relationships of serum free thyroxine and erythrocyte measures in euthyroid HFE C282Y homozygotes and control subjects: the HEIRS StudyINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2010J. C. BARTON Summary Hemoglobin (Hb) levels and mean corpuscular volume (MCV) are abnormal in some persons with hemochromatosis or thyroid disorders. We sought to determine whether serum free thyroxine (T4) affects erythrocyte measures in euthyroid adults with or without C282Y homozygosity. We evaluated 488 white HFE C282Y homozygotes and controls (no HFE C282Y or H63D; normal serum iron measures) identified in screening; we excluded those with thyroid disorders, anemia, erythrocytosis, or serum ferritin (SF) <34 pmol/l. In the remaining 141 C282Y homozygotes and 243 controls, we evaluated correlations of log10 free T4 with Hb, RBC, MCV, and red blood cell distribution width (RDW). C282Y homozygotes had lower mean age, higher mean Hb, MCV, and log10 SF, and lower mean RBC and RDW than controls; mean log10 free T4 did not differ significantly. In HFE C282Y homozygotes, there was no significant correlation of log10 T4 with erythrocyte measures. In controls, there was a positive correlation of log10 T4 with Hb (P = 0.0096) and a negative correlation with RDW (P = 0.0286). Among euthyroid white adults without iron deficiency, there are significant correlations of log10 free T4 with Hb and RDW in controls, but not in HFE C282Y homozygotes. [source] Evaluation of F cells in sickle cell disorders by flow cytometry , comparison with the Kleihauer,Betke's slide methodINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2007K. Y. ITALIA Summary Adult F cell numbers are raised in inherited haemoglobin disorders, such as , -thalassaemia and sickle cell anaemia, hereditary persistence of foetal haemoglobin, and some acquired conditions, such as juvenile myelomonocytic leukaemia, during acute erythropoietic stress and pregnancy. True foetal erythrocytes containing foetal amounts of HbF can also occur in the adult circulation during the leakage of HbF-containing cells from the foetus to the maternal circulation. In normal adults, HbF is restricted to a small proportion (3,7%) of red blood cells (RBC), termed ,F cells'. Techniques estimating the amount of HbF use lysates prepared from RBC, whereas those that estimate the adult F cell count use intact RBC. An accurate assessment of adult F cells in sickle cell disorders is important because increased adult F cells are associated with decreased morbidity in these disorders. In the present study, HbF levels were measured and adult F cell numbers were estimated in 100 blood samples (25 normal individuals, 25 sickle heterozygotes, 25 sickle homozygotes and 25 sickle , -thalassaemia cases), using high pressure liquid chromatography for HbF levels, and flow cytometry and the Kleihauer,Betke (KB) acid elution microscope slide method for cell counts. Flow cytometry gave a more accurate assessment of adult F cells, eliminating any manual error, as compared to KB, which was less sensitive and precise as it is based on subjective visual interpretation. [source] Venous stasis and routine hematologic testingINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2006G. LIPPI Summary Prolonged venous stasis, as generated by a long tourniquet placement, produces spurious variations in several measurable analytes. To verify to what extent venous stasis influences routine hematologic testing, we assessed routine hematologic parameters, including hemoglobin, hematocrit, red blood cell count (RBC), main cell hemoglobin (MHC), main cell volume (MCV), platelet count (PLT), main platelet volume (MPV), white blood cell count (WBC) and WBC differential on the Advia 120 automated hematology analyzer in 30 healthy volunteers, either without venous stasis (no stasis) or after application of a 60 mmHg standardized external pressure by a sphygmomanometer, for 1 (1-min stasis) and 3 min (3-min stasis). Although the overall correlation between measures was globally acceptable, the mean values for paired samples were significantly different in all parameters tested, except MCV, MHC, PLT, MPV, eosinophils, basophils and large unstained cells after 1-min stasis and all parameters except MCV, MHC, MPV and basophils after 3-min venous stasis. As expected RBC, hemoglobin and hematocrit displayed a significant trend towards increase, whereas WBC and the WBC subpopulations were decreased. Difference between measurements by Bland and Altman plots exceeded the current analytical quality specifications for desirable bias for WBC, RBC, hemoglobin, hematocrit, lymphocytes and monocytes in samples collected after either 1- and 3-min stasis. These results provide clear evidence that venous stasis during venipuncture might produce spurious and clinically meaningful biases in the measurement of several hematologic parameters, prompting further considerations on the usefulness of adopting appropriate preventive measures for minimizing such influences. [source] Significant differences between capillary and venous complete blood counts in the neonatal periodINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2003S.M. Kayiran Summary The normal capillary and venous hematologic values for neonates have not been defined clearly. It is well known that capillary blood has higher hemoglobin (Hb) and hematocrit (Hct) values than venous blood. In a recent study, we reported differences between capillary and venous complete blood counts (CBC) in healthy term neonates on day 1 of life. The aim of this study was to extend our previous investigation. Term neonates (n=141) were stratified into four groups by days of postnatal age: group 2 (day 7, n=38), group 3 (day 14, n=35), group 4 (day 21, n=32) and, group 5 (day 28, n=36). Data from our previous study were included in the statistical analysis as group 1 (day 1, n=95). A CBC and differential count were carried out on each capillary and venous sample drawn simultaneously. Within each group, the mean and standard deviation for each parameter in capillary and venous blood were calculated and then compared using the paired sample t -test. In all groups, the capillary blood samples had higher Hb, Hct, red blood cell (RBC), white blood cell (WBC), and lymphocyte counts. In each group, venous platelet counts were significantly higher than the corresponding capillary values. There was also a trend toward higher venous mean corpuscular volume, higher capillary polymorphonuclear leukocyte (PML) count and mean platelet volume in all groups. In both capillary and venous blood, Hb, Hct, RBC, MCV values and WBC, lymphocyte, PML counts decreased and platelet counts increased steadily during neonatal period. This study reveals that CBC parameters and differential counts may differ depending on the blood sampling used. The findings underline the importance of considering the sample source when using hematologic reference ranges for healthy or septic neonates. When interpreting results, the term ,peripheral blood' should be replaced with ,capillary blood' or ,venous blood' so that an accurate assessment can be made. [source] Red blood cells in the metabolism of nitric oxide-derived peroxynitriteIUBMB LIFE, Issue 10 2006Natalia Romero Abstract In this review we have analyzed the reactions of nitric oxide (·NO) with superoxide radical (O2·-) at the vascular compartment which results in limitation of the bioavailability of ·NO and the formation of peroxynitrite (ONOO-), a strong oxidant species. The intravascular formation of peroxynitrite can result in oxidative modifications of plasma and vessel wall proteins including the formation of protein-3-nitrotyrosine. The role of red blood cells (RBC) and oxyhemoglobin in the metabolism of intravascular peroxynitrite will be discussed. While RBC constitute an important 'sink' of both ·NO and peroxynitrite, redox reactions of these species with oxyhemoglobin may in part contribute to erythrocyte aging. The intravascular formation, reactions and detoxification of peroxynitrite are revealed as important factors controlling vascular dysfunction and degeneration in a variety of pathophysiologically-relevant conditions. iubmb Life, 58: 572-580, 2006 [source] Determination of the selenium requirement in kittens,JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 9-10 2003K. J. Wedekind Summary The purpose of this study was to determine the selenium (Se) requirement in kittens. Thirty-six specific-pathogen-free kittens (9.8 weeks old) were utilized in a randomized complete block design to determine the Se requirement in cats with gender and weight used as blocking criteria. Kittens were fed a low Se (0.02 mg/kg Se) torula yeast-based diet for 5 weeks (pre-test) after which an amino acid-based diet (0.027 mg Se/kg diet) was fed for 8 weeks (experimental period). Six levels of Se (0, 0.05, 0.075, 0.10, 0.20 and 0.30 mg Se/kg diet) as Na2SeO3 were added to the diet and were used to construct a response curve. Response variables included Se concentrations and Se-dependent glutathione peroxidase activities (GSHpx) in plasma and red blood cells (RBC) as well as plasma total T3 (TT3) and total T4 (TT4). No significant changes in food intake, weight gain or clinical signs of Se deficiency were noted. Estimates of the kitten's Se requirement (i.e. breakpoints) were determined for RBC and plasma GSHpx (0.12 and 0.15 mg Se/kg diet, respectively), but no definitive breakpoint was determined for plasma Se. Plasma TT3 increased linearly, whereas plasma TT4 and the ratio of TT4 : TT3 decreased in a quadratic fashion to dietary Se concentration. The requirement estimate determined in this study (0.15 mg Se/kg) for kittens is in close agreement with other species. As pet foods for cats contain a high proportion of animal protein with a Se bioavailability of 30%, it is recommended that commercial diets for cats contain 0.5 mg Se/kg DM. [source] Novel nanoporous membranes from regenerated bacterial celluloseJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Muenduen Phisalaphong Abstract Bacterial cellulose (BC) in an NaOH/urea aqueous solution was used as a substrate material for thefabrication of a novel regenerated cellulose membrane. The dissolution of BC involved swelling BC in a 4 wt % NaOH/3 wt % urea solution followed by a freeze,thaw process. The BC solution was cast onto a Teflon plate, coagulated in a 5 wt % CaCl2 aqueous solution, and then treated with a 1 wt % HCl solution. Supercritical carbon dioxide drying was then applied to the formation of a nanoporous structure. The physical properties and morphology of the regenerated bacterial cellulose (RBC) films were characterized. The tensile strength, elongation at break, and water absorption of the RBC membranes were 4.32 MPa, 35.20%, and 49.67%, respectively. The average pore size of the RBC membrane was 1.26 nm with a 17.57 m2/g surface area. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Weak inhibitors protect cholinesterases from strong inhibitors (paraoxon): in vitro effect of tiaprideJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2005G. A. Petroianu Abstract Weak and reversible inhibitors of cholinesterases, when administered before potent organophosphorus inhibitors (pretreatment), have the ability, to a certain extent, to protect enzymes from inhibition. Such a protective effect was demonstrated in vitro for metoclopramide and ranitidine. The putative mode of protective action of these substances is, when administered in excess, competition for the active site of the enzyme with the more potent organophosphate. The present paper presents results using another benzamide with weak cholinesterase inhibitory properties: tiapride (TIA). The purpose of the study was to quantify in vitro the extent that TIA conferred protection, using paraoxon (POX) as an inhibitor, and to compare the results with existing data obtained using TIA as a protective agent against dichlorvos (DDVP). POX is a highly toxic non-neuropathic organophosphate. While the use of parathion (the inactive prodrug which is metabolically converted to POX) has been restricted in most countries, the organophosphate is still responsible for a large number of accidental or suicidal exposures. DDVP is a moderately toxic, non-neuropathic organophosphate. Red blood cell (RBC) acetylcholinesterase (AChE) activities in whole blood and butyrylcholinesterase (BChE) activities in human plasma were measured photometrically in the presence of different POX and TIA concentrations and the IC50 was calculated. Determinations were repeated in the presence of increasing TIA concentrations. The IC50 of POX increases with the TIA concentration in a linear manner. The protective effect of tiapride on cholinesterase could be of practical relevance in the pretreatment of organophosphate poisoning. It is concluded that in vivo testing of TIA as an organophosphate protective agent is warranted. Copyright © 2005 John Wiley & Sons, Ltd. [source] Perioperative Results of the Aortic Root Replacement in Strict Graft Inclusion TechniqueJOURNAL OF CARDIAC SURGERY, Issue 5 2008Niyazi Cebi M.D. Therefore, the strict graft inclusion technique has been developed to avoid major complications. We present the early results after aortic root replacement in strict graft inclusion technique. Materials and Methods: The strict graft inclusion technique was performed in 28 patients between April 2001 and June 2006 in St-Johannes-Hospital-Dortmund, Dortmund, Germany. There were nine female and 19 male patients. The mean age was 57.78 ± 12.01 years (28 to 77 years). A type A aortic dissection and an ascending aortic aneurysm with aortic valve lesion were the indication to operation in patients. Results: There were no early mortality and postoperative rethoracotomy. The mean postoperative bleeding over mediastinal drains was 565 ± 310 mL. (100,2250 mL). In exception of the patients with preoperative double thrombocyte aggregation inhibitors therapy and postoperative consumption coagulopathy, the mean postoperative bleeding over mediastinal drain was 443.04 ± 171.59 mL (100,1100) in the first 24 hours, the transfusion rate was minimal, mean 0.39 ± 0.64 packed red blood cells (RBC) (0,4) and mean 0.14 ± 0.27 packed fresh frozen plasma (FFP) (0,4), whereas only in 18 patients (78.26%) out of 23 patients was a transfusion not necessary. The intraoperative and postoperative requirement for substitution of erythrocyte concentrate was mean 1 ± 1.28 packed RBC (0,5) and FFP concentrate was mean 1.21 ± 1.90 packed FFP (0,12). Conclusions: The strict graft inclusion technique for aortic root replacement represents a safe and feasible method to avoid bleeding from coronary ostial anastomoses, from aortic annular suture lines, and annular leak. [source] Strategies for developing multi-epitope, subunit-based, chemically synthesized anti-malarial vaccinesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 5b 2008M. E. Patarroyo ,,Introduction ,,P. falciparum invasion of RBCs ,,Merozoite proteins involved in invading erythrocytes ,,Erythrocyte proteins involved in merozoite invasion ,,The state of current worldwide anti-malarial vaccine approaches ,,A rational approach towards developing subunit-based synthetic vaccines ,,The immune response elicited by conserved HABPs ,,Structural analysis of native and modified HABPs ,,Secondary structure analysis ,,Native and modified HABP 3D structure explains some immunological phenomena ,,Supporting the haplotype , and allele-conscious TCR concept ,,Modified HABPs' 3D structure revealed a fit into HLA molecules ,,Conclusion Abstract An anti-malarial vaccine against the extremely lethal Plasmodium falciparum is desperately needed. Peptides from this parasite's proteins involved in invasion and having high red blood cell-binding ability were identified; these conserved peptides were not immun genic or protection-inducing when used for immunizing Aotus monkeys. Modifying some critical binding residues in these high-activi binding peptides' (HABPs') attachment to red blood cells (RBC) allowed them to induce immunogenicity and protection against expermental challenge and acquire the ability to bind to specific HLA-DRp1* alleles. These modified HABPs adopted certain characterist structural configurations as determined by circular dichroism (CD) and 1H nuclear magnetic resonance (NMR) associated with certain HLA-DR,1* haplotype binding activities and characteristics, such as a 2-Å-distance difference between amino acids fitting into HLA-DRp1 Pockets 1 to 9, residues participating in binding to HLA-DR pockets and residues making contact with the TCR, suggesting haplotyp and allele-conscious TCR. This has been demonstrated in HLA-DR-like genotyped monkeys and provides the basis for designing high effective, subunit-based, multi-antigen, multi-stage, synthetic vaccines, for immediate human use, malaria being one of them. [source] Conserved regions from Plasmodium falciparum MSP11 specifically interact with host cells and have a potential role during merozoite invasion of red blood cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2010Ana Zuleima Obando-Martinez Abstract Despite significant global efforts, a completely effective vaccine against Plasmodium falciparum, the species responsible for the most serious form of malaria, has not been yet obtained. One of the most promising approaches consists in combining chemically synthesized minimal subunits of parasite proteins involved in host cell invasion, which has led to the identification of peptides with high binding activity (named HABPs) to hepatocyte and red blood cell (RBC) surface receptors in a large number of sporozoite and merozoite proteins, respectively. Among these proteins is the merozoite surface protein 11 (MSP11), which shares important structural and immunological features with the antimalarial vaccine candidates MSP1, MSP3, and MSP6. In this study, 20-mer-long synthetic peptides spanning the complete sequence of MSP11 were assessed for their ability to bind specifically to RBCs. Two HABPs with high ability to inhibit invasion of RBCs in vitro were identified (namely HABPs 33595 and 33606). HABP-RBC bindings were characterized by means of saturation assays and Hill analysis, finding cooperative interactions of high affinity for both HABPs (nH of 1.5 and 1.2, Kd of 800 and 600,nM for HABPs 33595 and 33606, respectively). The nature of the possible RBC receptors for MSP11 HABPs was studied in binding assays to enzyme-treated RBCs and cross-linking assays, finding that both HABPs use mainly a sialic acid-dependent receptor. An analysis of the immunological, structural and polymorphic characteristics of MSP11 HABPs supports including these peptides in further studies with the aim of designing a fully effective protection-inducing vaccine against malaria. J. Cell. Biochem. 110: 882,892, 2010. © 2010 Wiley-Liss, Inc. [source] Performance of a new separator system for routine autologous hematopoietic progenitor cell collection in small childrenJOURNAL OF CLINICAL APHERESIS, Issue 6 2007Volker Witt Abstract The AMICUSÔ system was recently introduced for peripheral blood stem cell (PBSC) aphereses in adults. We conducted a single center field evaluation to obtain data about the performance of this system in children with a body weight (bw) < 25 kg. Results of blood priming procedures were compared to historical data obtained with the Fenwal CS3000+ (CS 3000). From August, 2001 to February, 2007, 47/178 (26%) PBSC aphereses procedures were performed in our institution with the AMICUSÔ system in 35 small patients (median bw 13.9 kg; range 6.7,24; age 2.78 years; range 0.97,7.06). The patients suffered from various malignant primary diseases or recurrences. We primed the system with packed RBC in case of >30% dilution of the RBC volume (n = 31) or with saline (n = 16). Compared to the CS3000, the AMICUSÔ revealed comparable collection efficiencies (CE) for CD34+ cells (median 67%, range 26,120), lymphocytes (75%, 25,138), monocytes (54%, 23,173), and granulocytes (10%, 1.5,36), MNC (57% 24,125), but a significantly higher erythrocyte and granulocyte, and a lower platelet CE. There was a significant negative correlation between total leukocyte count and CE for MNC (r = ,0.566; P < 0.001) and CD34+ cells (r = ,0.517; P < 0.001). There was no significant statistical or clinical difference between the CE in blood-primed procedures and saline-primed procedures. With the AMICUSÔ we saw statistically less citrate reactions compared to the CS 3000. We conclude that the AMICUSÔ system is safe and efficient to harvest PBSC on a routine basis in pediatric patients, even in children ,10 kg bw. J. Clin. Apheresis, 2007. © 2007 Wiley-Liss, Inc. [source] Role of enzyme-treated cells in RBC antibody screening using the gel test: a study of anti-RH1, -RH2, and -RH3 antibodiesJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 2 2007Jocelyne Conne Abstract The role of enzyme-treated cells (ETCs) in red blood cell (RBC) antibody screening has been the subject of controversy, and its place in the clinical routine remains to be determined. In this work, plasma samples containing anti-RH1 (anti-D; N = 10), anti-RH2 (anti-C; N = 10), or anti-RH3 (anti-E; N = 10) antibodies were studied. The samples were diluted in nonbuffered or buffered normal saline, as well as in a pool of AB plasma samples. Titers and scores were determined by means of the gel test, using the indirect antiglobulin test (IAT) as well as ETCs, with R0r, r,r, or r,r test cells. Our results showed that compared to the IAT, ETCs allowed a clearer detection of anti-RH2 and anti-RH3, but not of anti-RH1 antibodies. Based on our study, it is not clear whether the ETC phase of the gel test should be maintained for RBC antibody screening. J. Clin. Lab. Anal. 21:61,66, 2007. © 2007 Wiley-Liss, Inc. [source] Relationship between renal anemia and prognostic stages of IgA nephropathyJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 2 2005Seiki Aruga Abstract In 2002, the Joint Committee of the Special Study Group on Progressive Glomerular Diseases, Ministry of Health, Labor and Welfare of Japan newly revised the clinical guidelines for IgA nephropathy (Sakai et al.: Jpn J Nephrol 37:417,421, 1995; Tomino and Sakai: Clin Exp Nephrol, 7, 93,97, 2003). The prognostic stages were classified into four groups: the good prognosis group (Group I), relatively good prognosis group (Group II), relatively poor prognosis group (Group III), and poor prognosis group (Group IV). The relationship between the levels of Hb, Ht, and RBC in peripheral blood and the renal prognostic stages was determined in 62 patients with IgA nephropathy in the present study. The mean levels of Hb, Ht, and RBC were significantly lower in Group IV than in Group I (P<0.05). However, there were no significant changes in the levels of serum creatinine (s-Cr) or creatinine clearance (CCr) among these four groups. It appears that the levels of Hb, Ht, and RBC in peripheral blood may be important clinical parameters for the evaluation of prognostic stages in patients with IgA nephropathy. J. Clin. Lab. Anal. 19:80,83, 2005. © 2005 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||